forum thyssen krupp

forumTechnische Mitteilungen ThyssenKrupp December 2001

English Edition

TK

forumThyssenKrupp 2/2001

02

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ThyssenKrupp AGCorporate Department TechnologyAugust-Thyssen-Strasse 140211 Düsseldorf, GermanyPostfach 10 10 1040001 Düsseldorf, GermanyPhone +49/2 11/8 24-3 62 91Fax +49/2 11/8 24-3 62 85

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ISSN 1438-9754

Cover

Long proven in general engineering,

handling and mining equipment, cranes

and earthmoving machinery, large-

diameter bearings are now also a key

component of many new technologies,

such as wind turbines, offshore facilities,

communications engineering and

aerospace equipment.

Hoesch Rothe Erde has earned

international recognition as a producer of

high-quality, dependable large-diameter

bearings, with an extensive range covering

a wide variety of applications.

The cover picture shows a three-row roller

bearing with the third ring not yet

mounted, revealing the radial and support

races. The bearing is of special-purpose

design as it has steel cages with bronze

runners, a complex configuration which is

used when temperatures exceed 80 °C

(e.g. foundry, steel mill) or for continuous

operation (e.g. tunnel boring machine).

Foreword03

Prof. Dr.-Ing. Ekkehard D. Schulz, Chairman of the Executive Board of ThyssenKrupp AG

Dear Readers,

Many people still associate ThyssenKrupp

only with steel. But this fails to do justice to

the Group‘s wide range of products and

services. ThyssenKrupp enjoys success in

many other areas, such as automotive

supply, services, materials trading, and

capital goods for the mechanical and plant

engineering and transportation sectors.

Selected examples from the latter area are

presented in this issue of “forum – Tech-

nische Mitteilungen ThyssenKrupp”.

The transportation of people and freight

takes many forms. We have elevator

activities around the globe providing

products and services in close proximity to

markets. Our range takes in not only

passenger and freight elevators, but also

escalators, moving walks, aircraft

passenger boarding bridges and stair lifts.

In addition to meeting the most stringent

safety specifications, these products also

satisfy ever increasing esthetic and

economic requirements.

An order from China has provided the

breakthrough for the Transrapid magnetic

train. ThyssenKrupp plays a major part in

this as an exclusive supplier of key

Transrapid components.

Shipbuilding is another area of activity.

We have a range extending from special-

purpose merchant vessels and mega-

yachts through naval shipbuilding to all

kinds of ship repair work.

In mechanical and plant engineering we

specialize in the production of complex

capital goods, special-purpose machines

as well as engineering systems and

components. Our expertise focuses on the

development of processing technologies,

the efficient design of production processes

and design engineering, and is thus the

key to producing highly efficient plants,

machinery and equipment tailored to

individual customer specifications. From

machine tools and conveyor systems to

chemical and cement plants, the com-

panies of the ThyssenKrupp Group display

outstanding capabilities in their respective

fields and hold leading world market

positions.

Yours,

Ekkehard Schulz

Prof. Dr.-Ing. Ekkehard D. Schulz,Chairman of theExecutive Board ofThyssenKrupp AG


Contents04


Dipl.-Ing. Hans-F. Frhr. v. Scholley,Head of Engineering Development,Thyssen Aufzugswerke GmbH, Neuhausen a.d.F.Page 9

Dipl.-Ing. Dagmar Euler-Schreiter,Head of Düsseldorf Airport project,Thyssen Aufzüge Düsseldorf GmbH, DüsseldorfPage 13

Almudena Sainz,Marketing Department,José R. Magallón,Sales Department Director,Thyssen Henschel S.A., Mieres, SpainPage 18

The EVOLUTION® traffic elevatorfor railroad station platforms fromThyssen Aufzugswerke

As part of a nationwide project to specify

a standard elevator for railroad station

platforms, a joint project team from Deut-

sche Bahn and Thyssen Aufzugswerke

developed the machine-room-less

EVOLUTION® traffic platform elevator.

Disabled access and security against

vandalism were key factors determining

the size and equipment of the elevator car.

Disabled accessibility was achieved by

designing the elevator car big enough to

facilitate wheelchair users and with con-

trols at a reachable height, providing audio

announcement modules and ensuring

high-precision stopping regardless of load.

The use of a glass-paneled car allowing

good visibility from outside helps dissuade

vandals and gives passengers a feeling of

added security.

Limiting the nominal travel speed and

hoisting height made it possible to increa-

se the maximum permissible elevator car

weight without the need for special techni-

cal support solutions, allowing the princi-

ple of a machine-room-less standard ele-

vator despite the high weight of the fully

glazed car.

The design of the EVOLUTION® traffic

convinced Deutsche Bahn to such an

extent that they awarded Thyssen Auf-

zugswerke a framework supply agreement.

Innovative elevators and escala-tors for a safe future

With their state-of-the-art elevators,

escalators and passenger conveyors,

Thyssen Aufzugswerke GmbH and Thys-

sen Fahrtreppen GmbH hold leading natio-

nal and international market positions.

This is clearly reflected in the moderniza-

tion and reconstruction work being carried

out at Düsseldorf Airport under the “air-

port 2000 plus” project.

Alongside hydraulic and traction units,

the 50 elevators installed also included the

new Evolution® model, which saves costs

and space by dispensing with the machine

room.

The 31 passenger escalators installed in

Pier B and Hall C have rises of up to 7.52 m

and fit in ideally with the architectural

design of the new airport.

A monitoring system developed by

Thyssen Aufzugswerke and specially adap-

ted to airport requirements has been set

up in the security control center. Alongside

status and fault message displays, the

monitoring system can also be used to

perform specific switching commands. Fire

protection equipment has been integrated

to identify fires anywhere in the airport at

an early stage; the control system auto-

matically initiates the required actions – from

deactivating the escalators to dynamic

elevator evacuation runs.

ThyssenKrupp Airport Systemspassenger boarding bridges atDüsseldorf International Airport

Passenger boarding bridges from Thys-

senKrupp Airport Systems are the result of

decades of experience in the airport equip-

ment sector. More than 1,300 units have

been installed worldwide.

ThyssenKrupp Airport Systems has been

supplying passenger boarding bridges to

Düsseldorf Airport since 1972 – 46 units

had been installed by mid-2000 – and is

also involved in the “airport 2000 plus”

reconstruction and expansion project

started in 1997.

The telescopic apron drive bridges

used offer greater maneuverability than

the alternative T-bridge and noseloader

designs.

The apron drive bridge made by Thys-

senKrupp Airport Systems differs from

competing products through the use of hot

dip galvanized steel sheets for the struc-

ture of the tunnel – guaranteeing a mini-

mum 20-year lifespan – and the use of a

hydraulic elevating system which provides

superior control and reliability compared

with electromechanical systems.

In 2000, ThyssenKrupp Airport Systems

started production at a new passenger

boarding bridge production facility in

Mieres, Spain. This new factory raises the

annual production capacity of the two

manufacturing centers in Mieres and Fort

Worth, USA, to 300 passenger boarding

bridges.

Contents05


Dipl.-Ing. Friedhelm Worpenberg,Head of Research and Development,Thyssen Henschel S.A., Mieres, SpainPage 22

Dipl.-Ing. Jörg-Peter Körner, Managing Director,Dipl.-Ing. Michael Bork, Senior Process Engineer,Dipl.-Ing. Heribert Dierkes, Senior Sales Engineer,Dipl.-Chem. Dr. Peter Nünnerich, R&D Manager,Dipl.-Ing. Volkmar Steinhagen, Process Engineer,Uhde Hochdrucktechnik GmbH, HagenPage 31

Dr.-Ing. Robert J. Bartels,Managing Director Hüller Hille GmbH / SalesCross Hüller,Dr.-Ing. Manfred Berger,Senior Sales Manager Cross Hüller,Hüller Hille GmbH, LudwigsburgPage 26

“DUAL” and “LOWRIDER”, twonew passenger boarding bridgesfor small and medium passengeraircraft

In recent years, the number of 20 to

120-seater commuter aircraft and regional

jets has increased rapidly. Embarking and

disembarking for this aircraft category

(with on-board stairs) still generally takes

place out on the apron with no protection

from the elements. The idea of developing

a passenger boarding bridge for commuter

aircraft was born of the wish to offer pas-

sengers the level of comfort to which they

are accustomed from larger aircraft. To

enable both first floor and ground floor

variants (depending on terminal type),

Thyssen Henschel has developed two new

passenger boarding bridges – the “DUAL”

and “LOWRIDER” models.

The DUAL bridge is connected to the ter-

minal at first floor level and can be docked

with the doors of all commercial commuter

planes via two telescopic tunnels. The

pendulum floor of the cabin can be shifted

laterally to allow docking with aircraft

whose on-board stairs do not have fold-

down railings.

The LOWRIDER bridge is connected to

the terminal at ground floor level. An espe-

cially low drive unit is provided to position

the cabin against the aircraft so as to allow

virtually horizontal embarking/disembar-

king.

Both passenger boarding bridges are

available in “steel” and “glass” versions,

differing only in the closed or open design

of the tunnel side walls.

New applications of high-pressureextraction

Extraction with supercritical gases is a

very important area of high-pressure tech-

nology. Uhde Hochdrucktechnik GmbH has

developed many such applications since

1980 and has filed or applied for world-

wide patents for associated components

and processes. The company is also market

leader in this field, supplying equipment to

customers worldwide, particularly in Asia,

Europe and the USA.

As part of a government-funded re-

search project into the recycling of liquid-

containing polymer components, Uhde is

continuing its tradition as a leading innova-

tor in the field of high-pressure extraction.

The special properties of liquid-contain-

ing polymer components, such as plastic

fuel tanks, call for new recycling methods.

This has become increasingly important to

the automobile industry, as the EC end-of-

life-vehicle directive and the German law

on scrapped vehicles (coming into force in

2002) mandate rising recycling quotas for

the component materials and place limita-

tions on thermal recycling.

Manufacturing flexibility in power-train production

The Hüller Hille group is one of the

world’s leading manufacturers of machine

tools. Its biggest customer group are

manufacturers from the engine/automotive

industry and their suppliers.

Ever shorter strategy validity, the increas-

ing use of platforms, brand and company

consolidations, outsourcing decisions and

increasingly stringent emission regulations

give rise to a high degree of uncertainty

when planning volumes and product vari-

ants.

In response to this there has been a sig-

nificant increase in the demand in recent

years for flexible production systems to

allow for future changes in powertrain

manufacture.

Alongside classic transfer lines, which

still offer the lowest unit costs for produ-

cing largely standardized parts in high

volumes, there is a growing use of agile

and flexible production systems. A general

distinction is made between sequential

and parallel production together with

hybrid systems, which comprise various

aspects of transfer lines and special-pur-

pose machines.

A system producing cylinder heads for a

North American automaker is used as an

example to show that demands for work-

piece variation, output flexibility, system

configurability and a production network

comprising several plants can only be met

by a fully flexible agile production system.

Contents06


Dipl.-Ing. Klaus Schneiders, Member of theExecutive Board, Technology,Dr.-Ing. Albert Zimmermann, Senior SalesManager,Dipl.-Ing. Gerhard Henßen, Process EngineerElectrolysis,Krupp Uhde GmbH, DortmundPage 36

Dipl.-Ing. Andreas Halbleib, Project Leader, Raw Materials Processing,Dr.-Ing. Uwe Maas, Project Leader, Clinker Production,Dipl.-Ing. Franz-Josef Zurhove, Product Manager, Cement Production,Krupp Polysius AG, BeckumPage 41

Dipl.-Ing. Christof Brewka,Vice President Engineering – Structural &Mechanical,Krupp Robins Inc., Englewood, USADipl.-Ing. Martina Shehata, MSc, P. Eng.,Vice President Engineering & Project Manage-ment,Krupp Canada Inc., Calgary, CanadaPage 49

Membrane electrolysis – innovati-on for the chlor-alkali industry

With its low energy, low pollution mem-

brane technology, Krupp Uhde is an inter-

national market leader in the construction

of chlorine and caustic soda production

plants. This is proven by the construction

of 78 new plants and 18 upgrade or

revamping projects with a total capacity of

almost 4.4 million metric tons of caustic

soda.

The specific energy consumption of

chlor-alkali electrolysis plants is key to

their economic efficiency. For this reason

all components of the electrolysis cell are

subject to ongoing optimization in terms of

energy requirements, durability and mate-

rials. Krupp Uhde’s single cell element

combines optimal material choice with

simple cell maintenance. Corrosion-proof

materials guarantee maximum cell life.

Continuous design improvements to the

current-conducting elements have minimi-

zed electrical losses.

Older processes, such as the diaphragm

and amalgam methods, are being phased

out because of their high energy con-

sumption and low environmental friend-

liness. Krupp Uhde has already converted

many of these plants to the new mem-

brane technology, and others will follow.

A new variant for further reductions in

energy loss during chlor-alkali electrolysis

is the use of gas-diffusion electrodes

(GDE) as an oxygen-consuming cathode.

In collaboration with a specialist company,

Krupp Uhde has succeeded in producing

silver GDEs with low PTFE content which

have been successfully adapted to chlor-

alkali technology in test cells.

Developing the future in cementmanufacturing technology

Today cement is one of the most impor-

tant building materials, and our modern

world would be unthinkable without it.

Worldwide cement consumption is current-

ly around 1.6 billion metric tons per year.

Annual increases in demand of around 33

million tons call both for new production

plants and also for the modernization of

existing production units.

Cement plant construction today focuses

on reducing investment and operating

costs and improving environmental com-

patibility. In this respect, the research and

development department at Krupp Polysi-

us has an important role to play.

Strong competitive pressure on the

international markets necessitates a high

degree of innovation at a high technical

level.

The company continually faces up to

this challenge and develops units and entire

plants for all areas of cement production –

from raw materials preparation to clinker

production to cement production – deliver-

ing high flexibility, excellent quality control

and a high degree of automation to meet

all requirements for economical and ecolo-

gical cement production.

Krupp Canada supplies theworld’s largest downhill conveyorsystem

Krupp Canada received an order to build

a downhill conveyor for a Chilean copper

mine covering a length of 12.7 kilometers

and an elevation drop of 1,307 meters.

To protect it against avalanche and

landslide hazards, the conveyor is routed

through tunnels for almost its full length.

As no conveyor belt of this length would

be able to withstand the belt tensions

generated in a single flight, the system

consists of three sections.

The drive units feature squirrel cage

induction motors, two-stage helical bevel

reducers and mechanical disc brakes. In

the loaded condition, the drives act as

generators and feed power back into the

grid. The inverter drive system allows step-

less, smooth adjustment of torque and

speed to minimize dynamic stresses.

To prevent conveyor run-away under full

load on this downhill system, a sophistica-

ted control system was developed with five

levels of safety to bring the conveyor

system to a controlled stop in any condi-

tions.

Due to the high forces involved, a new

approach had to be taken with regard to

belt design so as to ensure the strength of

the belt and splices and allow advance

recognition of any impending splice failure.

Contents07


Burckhard Bussmann,Product Manager, Energy Technology,Dr.-Ing. Jürgen Schilling,Project Leader, Energy Technology,ThyssenKrupp EnCoke GmbH, BochumPage 56

Dipl.-Ing. Martin Braun,Object Manager FES,Dipl.-Ing. Achim Hollung,Project Manager E-System FES,Thyssen Nordseewerke GmbH, EmdenPage 68

Dr. jur. Reinhard Mehl,Head of Marine Sales Germany / Project LeaderF124,Blohm + Voss GmbH, HamburgPage 63

SVI Noord-Brabant sewage sludgeincineration plant, Netherlands

ThyssenKrupp Encoke emerged success-

ful from an international request for bids to

develop a central sewage sludge inciner-

ation plant for SVI Noord-Brabant.

With an installed capacity of 133,000

metric tons of dry material per year, the

plant is the biggest of its kind in Europe. In

terms of volume and the properties of the

unavoidable waste products, the facility

was designed to maximize the amount of

recyclable residue and thus minimize the

amount of waste to be disposed of.

The dewatered sludge is transported

to the plant by road and dumped in deep

storage bins.

After pre-drying in steam-heated disc

dryers, the sludge is incinerated without

any additional energy in a fluidized bed

incinerator using the ThyssenKrupp EnCoke

process.

The flue gases exiting the fluidized bed

incinerator are used to generate saturated

steam for sludge drying and wastewater

evaporation. The flue gases are dedusted

in an electrostatic precipitator and then

pass through a scrubbing process.

The incineration residues are mainly

recycled into building materials, a small

amount of waste is disposed of ecologically.

Experience from four years of service

has shown the plant to meet all expecta-

tions in full.

Research and testing vessel fromThyssen Nordseewerke

In December 2000, Thyssen Nordsee-

werke was awarded a contract to build a

research and testing vessel.

The design of the SWATH vessel (Small

Waterplane Area Twin Hull) is characterized

by a relatively wide platform mounted on

narrow struts ending underwater in two

large hulls similar in shape to a sub-

marine. This design provides platform

stability even in heavy seas and thus mini-

mizes restrictions on research activities

caused by bad weather.

The shape of the hulls has a key influ-

ence on resistance and damping. The

trapezoidal shape selected offers optimum

damping; the hull cross section tapers

continuously toward the stern and the bow

to offer significantly lower resistance than

a cylindrical hull.

The propulsion concept is also new:

The design of the power generation and

propulsion equipment is similar to that of

an all-electric vessel, with key components

such as the propulsion motors and the

generators utilizing permanent magnet

technology. Propulsion is via four identical

PM synchronous motors (2 per shaft); four

PM current generating units are powered

by diesel engines.

All the vessel’s systems are designed for

24-hour unsupervised automatic operation.

The “Sachsen” – impressionsfrom the sea trials

The Sachsen is a German navy frigate

class F124 vessel. Five years after the

order was placed, in August 2001 the frig-

ate left the Blohm+Voss shipyards for sea

trials.

The sea trials involve comprehensive

tests with the focus on the vessel’s

systems and machinery. They provide the

opportunity to optimize the ship’s systems

under operational conditions and detect

any faults in good time.

The main emphasis of the marine

systems trials is to test the combined

diesel and gas turbine propulsion system

(CODAG), which compared with the pre-

vious vessel generation dispenses with a

second turbine and markedly reduces op-

erating costs over the life of the frigate.

Also on test is the newly developed data

bus-based integrated monitoring and con-

trol system (IMCS), which monitors and

controls all on-board marine systems via

more than 7,000 monitoring stations dis-

tributed throughout the vessel.

As major elements of the complete

system were developed in parallel with the

construction of the frigate, to minimize

development risks a risk management

team was deployed to permanently moni-

tor all developments and ensure their sub-

sequent integratability.

Contents08


Dr.-Ing. Jörg Rollmann,Head of Research & Testing,Hoesch Rothe Erde GmbH, LippstadtPage 74

Dipl.-Ing. Winfried Kracht,Chairman of the Management Board,Luitpold Miller,Member of the Management Board,Dr.-Ing. Friedrich Löser,Chief Section Head Systems Technology,ThyssenKrupp Transrapid GmbH, KasselPage 79

Wolfgang Schmidt,Managing Director,Hogema Maschinenhandel GmbH, Cologne5

Environmentally friendly marinepropulsion systems rely on large-diameter antifriction bearingsfrom Hoesch Rothe Erde

Large-diameter bearings are used in

different forms in virtually every segment

of mechanical engineering and transporta-

tion. Since the early 1980s, these bearings

have also been used in marine applica-

tions for thruster systems on vessels whose

operation calls for high maneuverability,

such as tugboats and ferries. The large-

diameter bearings transmit forces and

moments from the thrust bearings of the

ships’ propeller screws.

The development of pod propulsion

systems is now expanding the range of

large-diameter bearings to include cruise

ships with significantly higher propulsive

power. To eliminate the weak point of the

Z-drive between the drive motor in the ship

and the propeller screw on conventional

thrusters, on pod units the motor and pro-

peller screw are housed in a pod, mounted

with 360° rotation beneath the hull of the

ship on a vertical shaft and a large-diame-

ter bearing (azimuth bearing). This solution

increases maneuverability and reduces

fuel consumption.

Pod propulsion units are generally

mounted on three-row roller-bearing slew-

ing rings. As combined axial-radial roller

bearings they can withstand high

moments of tilt and ensure the reliable

functioning of the propulsion system.

Transrapid – innovative rail tech-nology for the world market

The Transrapid system was designed for

passenger transport at speeds of up to

500 km/hour. The heart of the Transrapid

technology is a non-contacting electro-

magnetic levitation, guidance and propulsion

system which replaces the functions of

wheel and rail.

Propulsion is via a traveling magnetic

field generated in the guideway by a long-

stator linear motor, which propels the train

synchronously via its support magnets.

The vehicle wraps around the guideway

and is therefore prevented from derailing.

Deformation elements arranged on the

levitation frame ensure operational safety

in the event of collisions with stationary

objects on the guideway.

The components of the long-stator linear

motor responsible for the suspension, guid-

ance, propulsion and braking functions –

stator packs and long-stator windings –

are located in the guideway. The long-

stator winding is realized as a three-phase

traveling field winding, with each winding

strand created by means of meandering

and bending of the traveling field wire and

pressed into the slots of the stator packs

by a mobile laying unit on the guideway

supports.

Location reference flags attached to the

guideway allow the trains to be located

using the operation control technology.

The switches are of welded steel and are

shifted and locked electrically.

Certified pre-owned CNC machines: The alternative to newequipment

Trading in used machine tools offers

significant opportunities. Hogema Maschi-

nenhandel GmbH, a subsidiary of the

Hommel Unverzagt group, has moved into

this business and offers certified pre-

owned CNC machine tools along with the

same range of services available to new

equipment customers. Every year, around

100 machines change owners via existing

customer relations with sister companies,

the company’s own website or internat-

ional marketplaces.

The machines are inspected at in-house

technical centers, overhauled and repair-

ed. Customers can personally check out

the excellent quality of the pre-owned

machines there before buying, and

demonstrations are also possible.

Like its sister companies selling new

machines, Hogema offers its customers

tailored purchasing and insurance models

to ensure customers’ liquidity indepen-

dently of banks. The extensive after-sales

service offers not only classic services

such as inspection, maintenance and

repair, but also a highly efficient service

hotline to ensure high machine availability.

09


Elevator with kiosk and shaft (Fig. 1)

The EVOLUTION® traffic elevator for railroad station platforms fromThyssen Aufzugswerke

Dipl.-Ing. Hans-F. Frhr. v. Scholley

10


1 Requirements

Elevators for railroad station platforms

have to fulfill special requirements. They

are often the only access to public

transportation for the handicapped. These

elevators must therefore satisfy

requirements for barrier-free design

according to DIN 18024. Platform elevators

in any public transportation system also

face a high degree of exposure to

vandalism. Meeting such demands needs a

transparent design that is also robust.

Standard machine-room-less elevators

cannot fulfill these more demanding

requirements. The transparency required to

deter vandalism can only be sensibly

achieved by having an elevator car with

glass on all sides. The weight of such a

design has normally precluded its use for

standard machine-room-less elevators

(from all of volume manufacturers of whom

we are currently aware).

2 The “Standard Railroad StationPlatform Elevator” project

Up until now it has been common for

elevators to platforms at railroad stations to

be specially-built installations. In order to

reduce the cost of such systems and of the

difficult task of obtaining spare parts for

them while simultaneously improving their

quality, a nationwide project to specify a

standard elevator for railroad station

platforms was conducted by the German

railway company Deutsche Bahn. The

objective of the project involved offering

framework contracts to manufacturers to

develop largely standardized equipment

with a good price/performance ratio and a

secure supply of spare parts.

A joint project team from Deutsche Bahn

and Thyssen Aufzugswerke has now

specified an elevator for railroad station

platforms based on the EVOLUTION® range

of machine-room-less elevators. The

resulting design was so convincing that

Thyssen Aufzugswerke was awarded a

framework contract for the delivery of

machine-room-less elevators for railroad

platforms. This was how the EVOLUTION®

traffic was born – initially as a 3D CAD

model (Fig. 2).

2.1 Elevator car dimensions

The specifications for the dimensions

and outfitting of an elevator car are largely

influenced by suitability for the handi-

capped and security against vandalism. A

car suitable for the handicapped needs to

be at least large enough to accommodate

one individual in a wheelchair as well as

one accompanying person. The DIN 18024

standard specifies a minimum width of

1,100 mm, a minimum depth of 1,400 mm

and a minimum of 900 mm for the width of

the doors. According to ISO 4190-1, these

car dimensions correspond to an elevator

The EVOLUTION® traffic elevator for railroad station platforms from Thyssen Aufzugswerke

3D CAD animation of elevator car (Fig. 2)

11



with a 630-kg nominal load. To comply

with this, the EVOLUTION® traffic is to be

provided for nominal loads of 630 kg and

1,000 kg. The standard project plan

foresees a door width of 1,000 mm, with

either central or telescopic closing. There

may be a single entrance or doors on

facing sides.

2.2 Operating controls

One further aspect of suitability for

handicapped people is that controls to

operate the elevator should be within

reach. A wheelchair user must be able to

operate all controls without having to turn

around. DIN 18024-2 requires controls to

be at a height of 850 mm and at least

500 mm from the doors. The standard also

specifies a design for the operating panel.

Although European draft standards do

allow less expensive solutions for elevators

with handicapped access that do not

incorporate operating panels, the

EVOLUTION® traffic platform elevators will

all be equipped with panels that comply

with DIN 18024-2.

The vandal-resistant operating panel

features a stainless steel housing that

matches the stainless steel and glass

design of the elevator cab (Fig. 3). All

components are naturally resistant to

vandalism and are suitable for use by the

handicapped. The large aluminum buttons

measure 50 x 50 mm and comply with the

DIN 18024 and 18025 standards. They are

tactile and are denoted in 30-mm high

lettering and Braille.

Handrails are also matched to the

stainless steel and glass design. A double

configuration with rails at heights of

850 mm and 1,100 mm above the floor

meet the demands both of a lower handrail

for the handicapped as well as one higher

up to prevent collisions with the glass

walls. The rounded ends reduce the risk of

injury from bumping into or being crushed

against the rails. Handicapped access has

been achieved without compromise.

2.3 Comfort and security

The EVOLUTION® traffic elevators for

station platforms are all provided with an

adjustment system by which the level at

which the car halts can be set accurately

to within a few millimeters, even if the

elevator is heavily laden or when a heavy

load is removed. This considerably reduces

the likelihood of stumbling for partially

sighted or blind people. It also benefits

wheelchair users. The ease of use of the

elevators for blind and partially sighted

Handicapped-friendly, vandal-proof control panel (Fig. 3) Transparency inside and out (Fig. 4)

12



people can also be increased by means of

an optional audio announcement module.

The announcement can state the level

where the car is halting or even give

information specific to the customer’s

building. Calling the elevator is also made

easier for wheelchair users by the provision

of free-standing columns at an appropriate

distance from the doors. The height of the

controls on these columns and the controls

themselves are also in accordance with the

DIN 18024 and 18025 standards.

The maximum permissible weight for the

elevator car is 1,900 kg, which permits a

fully glazed design with lavish interior

outfitting. A transparent glass elevator

greatly reduces vandalism because its

interior is visible from outside (Fig. 4). But

being able to look out of the elevator car is

also pleasing for passengers inside it. It

reduces feelings of claustrophobia and

allows them to avoid the direct gaze of fel-

low passengers. Being visible from outside

also reduces the fear of harassment by

other passengers. The lower frame of the

windows reaches to a height of 250 mm

which prevents the glass from being

damaged by luggage trolleys. In addition a

protective bumper strip runs around it.

Furthermore, the elevator cars are equip-

ped with stainless steel floor troughs to

ensure resistance against corrosion even

by highly corrosive fluids. The troughs can

contain any of a wide variety of flooring

materials, artificial stone for example.

The EVOLUTION® traffic can be fitted in a

conventional concrete shaft or a shaft

frame. The top-floor halt is often contained

in a kiosk on the platform standing directly

in the open air (Figs 1 and 5). For this rea-

son the shaft doors have additional sealing

against rainwater and spray. The shaft

doors are also equipped with sill heaters for

use in winter.

2.4 Certification

Platform elevators need to fulfill not only

European elevator standards but also those

of the Deutsche Bahn itself. This means

that glass shaft doors need to withstand

almost twice as much kinetic energy as

specified in European standards. This is

tested for certification by means of a series

of tests involving pendulum strikes.

Thyssen Aufzugswerke’s self-produced,

eighth-generation doors were able to pass

the certification tests at the first attempt

with only minor modifications to the door

leaf guides.

2.5 Design

The EVOLUTION® traffic’s technical

specialty, however, is its cleverly engi-

neered design. By limiting the nominal

speed to 1.0 m/s and the hoisting height to

20 m, it was possible to raise the

maximum weight of the elevator car by

400 kg without resorting to specialized

solutions for supporting equipment. This

limiting of speed and hoisting height has

no adverse effect on the planning of plat-

form elevators since they do not usually

need to stop at more than three levels. In

this way it was possible to meet the special

demands on platform elevators without the

need for any special technical solutions for

the supporting equipment, enabling the

flexible EVOLUTION® family to be used as a

basis for a low-cost standard elevator for

railroad platforms.

Engineering drawing of the EVOLUTION® traffic in the shaft (Fig. 5)

13


Mobility provided by Thyssen elevators and escalators (Fig. 1)

Innovative elevators and escalators for a safe future

Dipl.-Ing. Dagmar Euler-Schreiter

14


1 Background

With the constantly growing demand for

mobility, whether in the private or the

professional sphere, people increasingly

need ever better ways to get to their

destinations even more quickly and com-

fortably. Expectations are high, as modes

of transportation with innovative engineer-

ing and modern design should be available

within a very short time. Despite all the

demands for innovation, aspects such as

safety and reliability are among the top

priorities.

In order to do justice to these criteria, the

companies Thyssen Aufzugswerke GmbH

in Neuhausen, Germany, and Thyssen

Fahrtreppen GmbH, Hamburg, began to

adapt their manufacturing program to the

new market conditions early on. As a result

of this new orientation, the two groups are

among the national and international

leaders in the market and have the most

modern assortment of intelligent elevator

solutions, escalators and passenger

conveyors. Thyssen Aufzüge and Thyssen

Fahrtreppen achieved this status also by

virtue of the high standard of quality met

by their products, which are used in

projects of all sizes.

2 Project example“airport 2000 plus”

This project name refers to a large

construction site at Düsseldorf Airport

whose objective is to complete moderni-

zation and reconstruction activities at the

airport without interrupting the overall

course of operations. This is a special

challenge for all the companies involved,

considering that, at peak hours, there are

as many as 800,000 people at this airport,

the third largest in Germany.

This project, the largest investment

project in the history of Düsseldorf Airport,

has its origin in an architectural compe-

tition to rebuild the airport that was an-

nounced after the fire of 1996. The task as

a whole encompassed the demolition of

parts of the main building and all of Pier B

and their reconstruction. An underground

car park is also being created, and the

existing Terminal C is being extended.

The full contract for this project went to

Thyssen Aufzüge Düsseldorf and included

supplying and installing 50 elevators and

31 escalators. The systems were delivered

by Thyssen Aufzugswerke GmbH in

Neuhausen and Thyssen Fahrtreppen

GmbH in Hamburg.

3 Elevators and escalators

Different versions of the elevator systems

were installed depending on the location.

Twenty-four systems are operated by a

hydraulic drive, and 26 traction elevators

have been installed. The number of

landings is between two and five, and one

of the systems is an elevator without

machine room that has a travel height of

2.18 meters – the smallest to date. Of the

24 traction elevators used, seven are Evo-

lution-type elevators without machine

rooms. In 1997, Thyssen Aufzüge in Neu-

hausen introduced the Evolution, a com-

pletely new machine-room-less elevator

design that has since become the trade-

mark of Thyssen Aufzüge. The absence of

the machine room, which was previously

planned as a small “house” on buildings,

means that the client is spared high costs,

and the architect can make better use of

the often limiting building line with an addi-

tional floor. In order to do justice to the

future market requirements in this area as

well, the Evolution was developed further. It

now breaks down into seven different

modules that can be used in accordance

with the type of building involved.

In order to fit in harmoniously with the

open and transparent design of the new


Terminal B at sundown (Fig. 2)

15


airport terminals, 15 glass elevators were

installed. The expense of a glass elevator

car of this sort is often underestimated, as

a high transparency on the part of the cars

entails a high dead weight. That results in

larger hydraulic units and the dissipation of

larger amounts of heat. The 12 cars of the

glass elevators that connect the multilevel

parking garage P1 with the main building

each have a dead weight of nearly 5 metric

tons, and can handle a loading capacity of

up to 2,450 kg.

The cars of the other passenger

elevators are equipped with stainless steel

paneling, mirrors, stainless steel skirt-

guards, handrails and stone flooring. The

passenger-freight elevator is equipped with

enameled paneling, guard strip, and

Norament flooring.

For the passenger transport in Pier B,

11 Tugela FT 845 escalators with rises of

6.62 to 7.04 m were used. In addition,

16 Velino FT 823 escalators were installed

in the main building, where they connect


stainless steel outer cladding and glass

balustrades, matching the architectural

style of the new airport.

Four more Velino FT 823 escalators are

planned for Hall C. Visually, the design of

the glass balustrade ensures that they fit in

extremely well with the overall style of the

departure hall, which is itself due for a

redesign.

The futuristic design aside, the products

of Thyssen Fahrtreppen make it the

acknowledged specialist in the field of

transportation facilities. Thyssen escalators

are particularly popular at airports,

because of their smooth and reliable

functionality. The technology of these

systems is designed in such a way that it

easily brings the huge number of persons

to be found every day at an airport to

their destinations. This flow of transport-

ation must be guaranteed, since a

stoppage of the systems or a holdup would

disrupt the entire course of a rapid

connection.

the three levels “Arrivals,” “Departures”

and the monorail. With rises of 2.18 to

7.52 m, the Velino FT 823 are the longest

escalators on the entire Düsseldorf Airport

site. These systems are furnished with

Thyssen escalators link arrivals and departures (Fig. 3)

Assembly of the two longest escalators in the new airport terminal (Fig. 4)

16



4 Monitoring

A monitoring system in the security

control center at Düsseldorf Airport is avail-

able for monitoring the elevator systems

and escalators. The system, which was

developed by Thyssen Aufzugswerke, was

specially adapted to conform to the desires

of the airport company and was sold to it.

Updates continue to be supplied by

Thyssen.

The following status and fault messages

are displayed concerning the escalators:

� Direction – up – down � Escalator stationary, moving� Step chain monitoring� Comb plate monitoring� Step misalignment� Handrail inlet guides� Emergency push button � Speed monitoring� Combination of individual messages as

multiple fault message� Principal voltage monitoring� Fire alarm

In the case of elevators, the following

status messages are shown in the overview

display:

� Location at floor level� Door position – open� Direction� Internal commands� Outside calls� Minimum load of 25 kg� Air passenger guidance system

activated (displayed on the monitoring

screen of the individual elevator)� Emergency call� Out of service� Maintenance and priority� Remote disconnection – off� Case-of-fire message� Case-of-fire detectors active per floor

� Loudspeaker fire alarm triggered� Stand-by power

The following fault messages for

elevators are displayed in plain text or as

pictographs:

� Power failure� Control and connection error� Stop outside of a door zone� Elevator car door not closed� Landing door not closed� Oil temperature over 70 degrees� Oil level monitoring� Safety circuit passive� Collective fault message

Switching commands can be executed

from the monitoring system:

� Remote disconnection (switching off

controls and light at any stop)� Car command for a run to another floor� Fire emergency simulation� Barring of landings� Reading out of error stacks

5 Fire protection/Fire control

Düsseldorf Airport has invested

approximately 100 million euros in fire

protection. There are 7,340 optical smoke

and heat detectors in the new terminal that

can identify fires anywhere at an early

stage; individual areas can be sealed off

with rolling doors. In the upper story of the

main building, 26 large ventilating fans

ensure that conflagration gases are extract-

ed quickly. In addition to the new rolling

doors, there is also a new electro-acoustic

alarm system that uses 4,700 loud-

speakers to warn visitors quickly in case of

an emergency.

Faults are recognized immediately (Fig. 5)

17 Innovative elevators and escalators for a safe future


As regards the elevators and escalators,

the airport fire alarm system sends a signal

to the Thyssen control center in the event

of a fire, and the appropriate measures are

then initiated. These measures are dis-

played via the monitoring system in the

security control center.

In the event of a fire, the escalators shut

down immediately. The elevators execute a

dynamic evacuation run. The goal of an

evacuation run of this sort is an automatic,

secure movement of the elevators to a

pre-determined landing at which the per-

sons in the elevators can reach a safe

stairwell or the outside via the shortest

route. To assist them, an announcement is

broadcast in German and English over the

voice communication system in the ele-

vator car. It informs them that there is a

failure and asks them to leave the elevator.

Intelligent passenger transport solutions (Fig. 6)

The elevator remains at the evacuation

landing with the door open and shuts

down. In conjunction with the system for

automatic early fire detection, this dynamic

elevator control system ensures that there

can be no intentional or accidental

movement of the elevator to areas affected

by fire.

All electrical lines to the controls are

designed to remain functional for at least

30 minutes and to operate with stand-by

power. The principal power supply lines to

the service room of the passenger

elevators are monitored at all points by

smoke detectors that likewise trigger an

evacuation run, since interruption to the

power supply would make an evacuation

run impossible and the elevator could

stop in the shaft between floors.

6 Outlook

Following a six-year construction phase,

the project will be completed in 2003. By

then, it is expected that over 600 million

euros will have gone into the reconstruction

of Düsseldorf International Airport. In terms

of safety, it will be in the top class of

international airports.

18


ThyssenKrupp Airport Systems passenger boarding bridges at Düsseldorf International Airport

Almudena Sainz,

José R. Magallón

TKAS passenger boarding bridge at Düsseldorf International Airport ( Fig. 1)

19



Apron drive bridge – side view (Fig. 3)

1 Introduction

In August this year, Düsseldorf Airport

awarded ThyssenKrupp Airport Systems

(TKAS) a contract for the replacement of

5 passenger boarding bridges (from

a total of 10) as part of the upgrading

program (airport 2000 plus) started in

1997.

This new order can be considered an-

other chapter in the permanent boarding

bridge supply project that ThyssenKrupp

Airport Systems has been carrying out at

this Airport since 1972.

In Germany, Düsseldorf Airport ranks

third after Frankfurt and Munich. It has

been owned, since its privatization in 1997,

by a consortium comprising Hochtief AG

(25%), Aer Rianta International (25%) and

the City of Düsseldorf (50%).

The airport has 3 terminals (A, B and C).

It suffered a serious fire in 1996, giving rise

to a rehabilitation and extension project

(airport 2000 plus) with a volume of over

€400 million in 1997. The construction of

the new Terminal (B) was entrusted to the

architects J.S.K. Perkins & Will.

The capacity of this terminal, officially

inaugurated in July 2001, is 16 million

passengers per year. In the spring of 2003,

when construction of Terminal C is comple-

ted, the airport’s capacity will be increased

to 22 million passengers per year.

2 Terminal B

ThyssenKrupp Airport Systems delivered

the last passenger boarding bridges last

July: 46 units since 1972.

9 Apron Drive units (see point 3) were

installed in gates B01 to B11 with the fol-

lowing operating lengths:

� 7 model TB 35/21-2 units (35 m exten-

ded, 21 m retracted)� 2 model TB 45/26.5 – 2 units (45 m

extended and 26.5 m retracted)

This last project, in contrast with pre-

vious ones, was totally supplied by the new

manufacturing plant that ThyssenKrupp

inaugurated in Mieres, Asturias/Spain in

the year 2000.

The new plant has a useful manufactu-

ring surface area of 10,800 m2 and a total

surface area of 24,000 m2. The plant has

the most modern equipment for manufac-

turing boarding bridges. The pressurized

painting cabins (35 x 6 m.) with the capa-

city for fast heat drying (over 70º C) and

collection of waste using a water curtain

are worth mentioning as well as the specia-

lized welding units designed specifically for

welding the side panels (of galvanized

plate) of the tunnels.

This new ThyssenKrupp Airport Systems

factory increases the Group’s manufactu-

ring capacity to 300 boarding bridges per

Düsseldorf International Airport (Fig. 2)

20



annum, distributed between its two manu-

facturing centers in Europe (Mieres, Spain)

and the U.S.A. (Fort Worth, Texas).

3 Passenger boarding bridges

For most airports, passenger boarding

bridges are no longer a system solely for

the comfort of the passengers in transit

through the terminal. This product is cur-

rently considered a key part in the design

and operating of large airports and a stra-

tegic element for efficiency in boarding and

disembarking operations for future large

capacity aircraft (A –380 or Boeing 747

Stretch).

Moreover, the esthetic concept of pas-

senger boarding bridges, as an architectu-

ral element attached to the terminal buil-

ding, plays an increasingly relevant role in

architectural studies for new airport

projects.

TKAS factory in Mieres, Spain (Fig. 4)

From an operating point of view, passen-

ger boarding bridges have undergone con-

stant evolution in design and, at present, are

classified according to the following types:

� T-Bridge

The oldest and simplest type of pas-

senger boarding bridge comprises two

rigid tunnels joined in a T-shape, in

which the longitudinal tunnel is provided

with vertical movement, while the trans-

verse tunnel is provided with telescopic

movement until it reaches the aircraft

access door.

� Noseloader

As an evolution of the previous concept

with regard to the transverse tunnel, the

cabin is provided with limited movement.

Approach to the aircraft is achieved by

means of telescoping and lifting the

longitudinal tunnel.

� Apron drive

This is the most developed bridge con-

cept and the one that allows the greatest

number of movements for serving the

aircraft. Horizontal movement is perfor-

med by driving a traction block (bogie),

which supports the structure of the

bridge and which, under cabin control,

allows movement in all directions.

Vertical movement is achieved by means

of an electro-mechanical or hydraulic

elevating system.

An apron drive passenger boarding

bridge (used in Düsseldorf) is made up of

the following elements:

� Rotunda

This element forms the interface

between the terminal building and the

telescopic tunnels of the boarding

bridge.

� Column

This is the fixed point on which the

boarding bridge is supported. Its height

varies depending on the floor level of the

terminal.

� Tunnels

Their length depends on the types of

aircraft to be served. Their lateral walls,

with two or three elements,

can be manufactured in metal or

glass.

� Cabin

The cabin, located at the airside end of

the boarding bridge, allows access to the

aircraft. It has a swivel-mounted floor

and includes the control and operating

system.

21



� Lifting unit

This allows the vertical movement of the

boarding bridge to adapt the cabin sill to

the height of the docking door of the

aircraft.

� Driving unit

This provides horizontal movement for

the bridge. It includes A.C. motors with

speed regulated by frequency conver-

ters.

� Safety devices

These include all those elements that

limit or control the movements of the

boarding bridge to avoid collision with

vehicles or the aircraft itself and to

ensure the safety of both the operation

personnel and the passengers.

4 TKAS boarding bridges

The TKAS boarding bridge is the result of

decades of experience in the airport equip-

ment sector. The more than 1,300 units

installed in airports worldwide are proof of

the market’s recognition of its superior

quality and technology.

The product manufactured by Thyssen-

Krupp Airport Systems is differentiated

from that offered by competitors by two

aspects proving the aforementioned con-

cepts. On the one hand, the use of hot

dip galvanized steel sheets for the struc-

ture of the tunnels, offering reliability

against rust that guarantees a minimum

20-year life span under adequate mainten-

ance protocols.

On the other hand, the hydraulic system,

in contrast with the electromechanical ele-

vating system, provides superior control

and reliability in vertical movements.

5 Next project

The new project launched by Düsseldorf

Airport represents the supply of

5 new apron drive boarding bridges, in

Terminals C (4 units) and A (1 unit), for

ThyssenKrupp Airport Systems.

This equipment will be manufactured

and supplied by the new TKAS factory

in Mieres, Spain, during the month of

January 2002.

Apron drive bridge – general concept (Fig. 6)

Apron drive bridge – frontal view (Fig. 5)

22


“DUAL” and “LOWRIDER”, two new passenger boarding bridges forsmall and medium passenger aircraft

Dipl.-Ing. Friedhelm Worpenberg

DUAL passenger boarding bridge in glass version (Fig. 1)

23


“DUAL” and “LOWRIDER”, two new passenger boarding bridges for small and medium passenger aircraft

DUAL passenger boarding bridge in glass version docked with a narrow body Boeing B 737 aircraft (Fig. 2)

1 Introduction

Thyssen Henschel is responsible for the

worldwide passenger boarding bridge

activities within the ThyssenKrupp Group.

At our central plant in Mieres, Spain we

develop new products for the demanding

passenger boarding bridge market.

Thyssen Henschel spearheads innovations

in this area and is investing increasing

amounts in research and development, in

line with rising demand and our growing

presence on the world market.

2 Background

Commuter aircraft or regional jets are

mainly used on short distance flights of

less then 1,000 km. Mostly used by

business travelers, they connect both

smaller airports with a major airport (HUB)

and interlink regional airports. Boarding

and disembarking of these aircraft still

mainly takes place at a distance from the

terminal.

Passengers are transported to and from

the commuter aircraft by buses and have

to brave all weathers when embarking or

disembarking via the on-board stairs.

Handicapped passengers have to be

carried on board or literally loaded using a

special lifting device. Airlines and airports

have long since realized that a fundamental

change is needed here if they are not to

lose out in the competition for business

passengers, who are accustomed to more

comfort.

Separate terminals are now being

planned and built for commuter aircraft and

regional jets at which the aircraft can be

positioned close to the building.

3 Marginal conditions fordevelopment

At commuter terminals, access to the

rotunda can be via first floor or ground

floor level.

Commuter aircraft and regional jets are

equipped with on-board stairs. On some

aircraft of this kind the stair railing can be

folded down (e.g. Canadair RJ) – on many

others, however, this is not possible (e.g.

ATR). On some propeller aircraft, the

propeller is very close to the door (e.g.

SAAB-340). In the USA in particular,

passenger boarding bridges have to satisfy

the strict requirements of US fire protection

standard NFPA 415. In the event of a fire

on the apron (spillfire) the passenger

boarding bridge must provide a safe

escape route for at least 5 minutes – i.e. it

must remain smoke- and fire-resistant and

keep temperatures bearable. Wheelchair

passengers should be able to negotiate

passenger boarding bridges easily and

without help (incline < 8.33%). If a

passenger boarding bridge is docked in

parallel to the aircraft it must be possible to

adjust the cabin floor in the horizontal

plane. The passenger boarding bridge

must have sufficient telescopic range to be

able to dock with the fore or aft doors of

the aircraft.

4 The “DUAL” passengerboarding bridge

This newly developed bridge type is very

similar to the well-known classic Thyssen

Henschel Apron Drive bridge. Like the

Apron Drive model, the “DUAL” passenger

boarding bridge (Figs 1 to 3) is provided

with a rotunda on the terminal side. The

swiveling range of the rotunda has been

limited to 90° and its diameter has also

been reduced considerably. The rotunda is

connected to the terminal at first floor level.

The passenger boarding bridge is connect-

ed to the rotunda through the inner of two

telescoping tunnels via a swivel bearing.

The aircraft-side outer tunnel features a

fixed bridgehead on which a swiveling

cabin is mounted. The elevating leg is

24



fastened to the outer tunnel approximately

half way along. The elevating leg is

supported via a central swivel joint on the

rotatable drive unit which is fitted with

pneumatic or solid tires. The “DUAL”

passenger boarding bridge can be

accessed from the apron via service stairs.

The bridge is controlled from a control

panel installed in the swiveling part of the

cabin.

What is really new about the “DUAL”

passenger boarding bridge – now largely

protected by pending and granted patents

(PZ 13877/PCT and 13872/PCT) – is the

fixed bridgehead which is offset by 35° to

the left and provided with a very large

window, as well as the laterally displace-

able pendulum floor in the swiveling

part of the cabin.

In comparison with standard cabins, the

cabin of the “DUAL” passenger boarding

bridge has a considerably smaller

diameter. The offset shape and off-center

rotation axis of the significantly lighter

cabin allow the “DUAL” passenger

boarding bridge to be positioned against

the nose door of commuter aircraft with

propeller drive (e.g. SAAB-340), which is

otherwise always a critical maneuver for

passenger boarding bridges. During

maneuvering the bridge driver has a good

view both of the on-board stairs with

railings and – thanks to the large window in

the bridgehead – the propeller drive.

The biggest advantage of the “DUAL”

passenger boarding bridge over rival

developments is its universal applicability

for all common commuter aircraft or

regional jets as well as narrow body aircraft

including the Boeing 757 and the Airbus

A 321 – at either the fore or aft doors. The

laterally displaceable pendulum floor also

allows risk-free docking with commuter

aircraft on which the railing of the on-board

stairs cannot be folded down (Fig. 3).

In addition, the pendulum floor meets

requirements specified in the marginal

conditions for slope compensation on a

“DUAL” passenger boarding bridge

docking in parallel with the aircraft. A

further very important advantage is that

strict fire protection requirements (US

standard NFPA 415) can be observed or

met without any restrictions.

5 The “LOWRIDER” passengerboarding bridge

This Thyssen Henschel development is

a variant on the “DUAL” passenger board-

ing bridge (Fig. 4). The rotunda of the

“LOWRIDER” passenger boarding bridge is

connected to the terminal at almost ground

floor level.

The horizontal swivel bearing (ball

bearing slewing ring) is bolted directly to

the anchor plate of the rotunda. Due to the

lower clearance under the bridge as

compared with the “DUAL” passenger

boarding bridge, the hydraulic unit is

installed at the side on the elevating leg. In

addition, an especially low drive unit with

solid tires is provided. Other than this, the

design of the “LOWRIDER” bridge is

identical with that of the “DUAL” bridge.

The advantages described for the

“DUAL” bridge also apply to the “LOW-

RIDER” bridge.

DUAL passenger boarding bridge docking with a Fokker F-50 commuter aircraft with on-board stairs andupright railing (Fig. 3)

25



6 “DUAL” and “LOWRIDER”passenger boarding bridges in“steel” and “glass” versions

As with all Thyssen Henschel passenger

boarding bridges, each of the newly

developed passenger boarding bridges is

available in a closed-design steel version

and an open-design glass version, i.e. with

glassed tunnel side walls. Apart from the

tunnel side walls, both passenger boarding

bridges in the steel and glass versions are

virtually identical, permitting the full

compatibility of all relevant sub-assemb-

lies. Such uniformity in the steel and glass

versions is unique in the passenger board-

ing bridge sector; on competitor bridges,

the steel and glass versions differ to such

an extent that they have only very few

compatible components. On Thyssen

Henschel passenger boarding bridges, the

steel version (Fig. 4) features hot-dip

galvanized steel sheet panels welded

between the tunnel corner profiles, while a

framework construction is used on the

glass version (Figs 1 and 2).

The type of glazing used on the outside

tunnel side walls depends on the prevailing

climatic conditions as well as on the safety

specifications (e.g. US fire protection stand-

ard NFPA 415). It may take the form of :

� single glazing� ISO double glazing� fire protection glazing

with panes of prestressed floatglass. The

specific advantages of Thyssen Henschel

passenger boarding bridges in glass

version as listed below are an indication

that airports are increasingly favoring the

glass version when purchasing new

passenger boarding bridges:

� Glass is permanently weather resistant

and reliably protects the supporting

structure of the side walls against

corrosion.� Glass is easy to clean and retains its

attractive appearance on a lasting basis.� During daylight hours the bridge lighting

remains switched off, saving energy,

maintenance and spare part costs.� Handrails can be integrated in the

supporting structure.� Problems of “tunnel claustrophobia”

are eliminated as transparent glass walls

replace the visible barrier of the tunnel

walls in the steel version.� The transparency of the glass side walls

considerably increases safety during

refueling because ground staff on the

apron can ensure that there are no more

passengers in the passenger boarding

bridge.� The appearance of glass passenger

boarding bridges fits in particularly well

with the modern architecture of many

airport buildings with glass facades.

7 Final remarks

In collaboration with Thyssen Stearns,

Thyssen Henschel has made a series of

proposals to the leading US commuter

carrier (American Airlines) regarding the

servicing of commuter aircraft with

passenger boarding bridges. To date, the

two passenger boarding bridges described

above are the most successful outcome of

this process.

The development of the “DUAL” and

“LOWRIDER” passenger boarding bridges

has given Thyssen Henschel a leadership

position in the commuter carrier market

segment. Launched in 1998, these

passenger boarding bridges are now used

at 12 airports worldwide.

LOWRIDER passenger boarding bridge in steel version (Fig. 4)

26


Manufacturing flexibility in powertrain production

Flexible machining of a crankcase (Fig. 1)

Dr.-Ing. Robert J. Bartels,

Dr.-Ing. Manfred Berger

27



1 Introduction

The Hüller Hille Group is part of the Metal

Cutting business unit of TK Technologies

and one of the world’s leading manufactur-

ers of machine tools. It produces standard

machining centers under the Diedesheim

brand – as used for one-off and small-

batch production – as well as vertical

turning machines (Hessapp), and transfer

lines and agile systems for large-batch

production (Cross Hüller).

By far the biggest customer group are

manufacturers from the engine/automotive

industry (OEM) and their suppliers. Recent

years have seen substantial changes in the

economic conditions for the type of

production facility used in this sector. As

such, the criteria used to decide upon new

investment have shifted too.By looking at a

system used to produce cylinder heads for

a well-known automobile manufacturer in

North America, we will show what effect

these changes have had on production stra-

tegy and the choice of production system.

2 Economic/operating conditions

When making plans for future produc-

tion, our customers today find themselves

faced with a growing number of uncert-

ainties. These concern factors such as

output volumes, the number of production

variants and their projected lifespan, the

need to comply with emissions regulations

that permanently change over time and

from country to country and which have a

considerable influence on engine design,

and the ever shorter validity of their own

corporate strategies (Fig. 2).

When planning new engine production

systems today, the following variables must

be taken into account:

� Variable valve timing (VVT)� Diesel direct injection (DID)� Gasoline direct injection (GDI)� Integrated starter/alternator/dampers

(ISAD)� (Electromechanical valve drive (EVA)� Cylinder cutout (CDA)� Alternative fuels (naturally occurring

gases, ethanol, methanol and propane)� Strengthened transmission flange in

response to increased torque

For example, the rapidly increasing use

of new high-performance diesel engines for

passenger cars was greatly underestimat-

ed. This, coupled with a resulting lack of

flexibility in production capacity, led to long

waiting times. At the same time, the

utilization of the production facilities for

gasoline engines of the same performance

class fell in some cases way below planned

capacity. Here, the use of agile production

systems would have been able to cushion

the impact of such a shift in demand.

At the same time, an increasing consol-

idation in the automotive industry together

with a corresponding move toward a

platform strategy has resulted in the amal-

gamation or even disappearance of certain

model series and variants. In turn, this has

led to substantial and unplanned fluctuat-

ions in production volumes.

In addition, the demand for flexible

production systems has also risen in

response to the fact that manufacturers

today are producing fewer and fewer of the

individual components used in production.

Indeed, in the majority of cases, manufac-

turers already buy in almost all of their

pistons, connecting rods, crankshafts and

camshafts from external suppliers, while

some are already talking about outsourcing

the manufacture of transmission housings,

cylinder heads and cylinder blocks.

In such an environment, it is crucial that

any investment decisions – which naturally

have an impact for a large number of years

to come – should also be taken with a view

to ensuring the greatest possible degree of

flexibility. When calculating unit costs, it is

therefore increasingly important to take into

account not only the pure capital expend-

iture and productivity factors involved with

investment in a new system but also its

ability to respond to future changes in

production needs. Here, it must also be

remembered that the more a production

system is designed to handle different

applications, the higher the volume of the

initial investment and therefore the unit

A market in transition (Fig. 2)

28



costs (Fig. 3). In order therefore to make a

sound business decision with regard to

investing in a flexible production system,

lifecycle costs must also be integrated into

the calculation.

3 The different typesof production

Alongside the classic transfer line, which

continues to represent the most economic

way of manufacturing large numbers of

more or less standardized parts, we are

witnessing a growing use of a variety of

flexible production systems.

Here, there is a general distinction to be

made between sequential and parallel

production together with so-called hybrid

systems, which comprise various aspects

of the transfer lines as well as special

machines (Fig. 4).

The major advantage of the transfer line

is that it comprises a special configuration

of machinery designed for a specific

manufacturing operation. The major

disadvantage, however, is that modifi-

cations are extremely costly if there are

any changes to the manufactured part. In

addition, such systems offer little flexibility

with regard to output volumes and attain

only average availability levels, as all the

various manufacturing operations involved

are linked to one another. Moreover, when

setting up such a system, the investment

required has to be made all at once and

must be directly tailored to the maximum

planned production volume. The advantage

of sequential flexible production, on the

other hand, is that it offers flexibility with

respect to output volumes, a phased

investment in line with a gradual build-up

of production (Fig. 5), and simpler linkage

between the various manufacturing

operations involved – although this also

brings the disadvantage that when one

machine stops, it brings the whole system

to a halt. By contrast, parallel production

not only features all the same advantages

but also offers maximum availability.

Should one manufacturing cell within the

system go down, production can still

continue.

Finally, all the manufacturing systems

offer optimal unit costs when operating

under the appropriate conditions.

4 The project

Flexibility is a major consideration not

only when it comes to manufacturing non-

standardized parts. Indeed, it can also be a

crucial feature of the systems used to make

identical products, particularly when these

are manufactured within a production

network involving several plants, or e.g.

different members of a product family that

are technically similar but may offer

a market alternative to one another

(e.g. V6 and V8 engines).

In the project for a North American

customer referred to above, such criteria

eventually led to a decision in favor of a

fully flexible production system. At the

planning stage, it was already known that

workpiece types for diesel engines, as well

Transfer lines and agile systems: A comparison (Fig. 3)

The transfer line; flexible, sequential and parallel production systems (Fig. 4)

29



as four-valve and twin spark plug tech-

nology would possibly be required in the

foreseeable future. The only way of

achieving such manufacturing flexibility at

an acceptable cost was to install an agile

system.

When a product family is manufactured

within a production network involving

several plants, the use of agile systems

can generate substantial savings with

regard to both the initial investment and

the space required to house the

equipment. This presupposes that the only

changes that need to be made to

production systems relate to the tools and

the NC programs. Once the supplier has

delivered the preprocessed workpiece, this

is then fitted with an adapter plate (Fig. 6),

which creates an identical interface to both

the machine tools and the production auto-

mation systems. In this way, the time and

costs involved in integrating a similar work-

piece into an existing production line can

be kept to a marginal amount.

In a flexible system, the manufacturing

process required to produce a component

ready for installation is broken down into

individual operations. In turn, this makes it

possible to use the machine tool best

suited for the kind of machining required.

This might involve a long or large machine

tool, for example, or equipment for special

processing. In order to achieve the

requisite production volume, a number of

identical machines are used in parallel for a

single operation. These parallel machines

are fed and discharged by the same

production automation system, using

gantry loaders, conveyor belts or robots.

Experience has demonstrated the advan-

tages of using gantry loaders with this type

of manufacturing operation, as this ensu-

res good access to the machinery as well

as helping to keep the area clean.

Gantry loaders or conveyor belts can

also be used to link up the individual

manufacturing cells within a module. Such

a system must not only transport the

workpieces but also provide a temporary

storage facility should there be any minor

disruptions (< 6-10 min) at an individual

manufacturing cell. With the help of this

technique, availability (80 – 90 percent)

well above that of conventional production

systems (60 – 75 percent) can be

achieved. Moreover, use of a parallel

production system ensures that

manufacturing will still continue when a

machine breaks down, which is not the

case with conventional production systems

employing a sequential approach.

Taking into account the complete

workpiece logistics required and the cost of

the production equipment, the ideal

capacity for a system of this kind lies

between 300,000 and 350,000 workpieces

per year. The actual size of the system

depends on the requirements for auto-

mation (max. six machines per manufac-

turing cell), metal cutting, subsequent

assembly systems, and the machines

Phased investment in line with required output volume (Fig. 5)

A cylinder head fitted with an adapter plate (Fig. 6)

Layout of a manufacturing module for 325,000 cylinder heads per year (Fig. 7)

Criteria evaluated for production system concepts(Fig. 8)

30



required to wash, assemble and leak-test

the workpieces at the metal-cutting stage.

The manufacturing module shown

produces 325,000 cylinder heads on 43

“SPECHT” machining centers every year

(Fig. 7). A total of four such modules,

which together generate an output of over

1.3 million cylinder heads a year, were

installed at the plant.

Once the workpiece has left the first

manufacturing cell, it is then trued up in

preparation for the adapter plate to be

fitted. This is screwed onto the workpiece

and remains attached until manufacturing

has been completed. A data-carrier on the

adapter plate contains production infor-

mation relating to the type of workpiece,

manufacturing specifications and geo-

metrical data. The production system is

controlled by the workpiece itself. As such,

a supervisory computer function is not

required.

Following premachining of the work-

piece, the valve guides and seats are

mounted. The screws used to fasten the

adapter are then released for a short

period so as to relieve stresses within the

workpiece. The next stage involves

completion of the machining work for the

inlet and outlet valves as well as milling

of the workpiece on both the combustion

chamber and hood sides. The camshaft

bearing cap is then mounted. In the next

manufacturing cell, the bore hole for the

camshaft is completed.

After all mechanical machining has been

finished, the workpiece is first separated

from the adapter plate before being

washed, fitted with a cap and tested for

any leaks. The cylinder head is then

prepared for final assembly. Meanwhile,

the adapter plate is washed in preparation

for another production run.

5 Outlook

The same customer also simultaneously

purchased a number of transfer lines for

the manufacture of cylinder heads in its

“bread-and-butter” program, where there

are far fewer construction modifications to

be expected in the course of the product

cycle. However, when it came to the engi-

nes for a new model series, the customer

opted for an agile system to manufacture

the cylinder blocks for the new V6 and V8

units. Behind this decision was an uncer-

tainty as to customer preferences between

the V6 and the V8 option. As such, it is dif-

ficult to predict with any accuracy the capa-

city required for either of the engine types.

Armed with such a flexible production

system, the customer is in an ideal position

to react to the current economic climate.

In Europe, the OEM industry currently

favors hybrid systems, not least because

this continues to represent the best invest-

ment of capital. However, should the trend

toward outsourcing strengthen further, we

may well see manufacturers turning toward

fully flexible production systems as a way

of increasing their options. The supply

industry has always invested in production

systems that are flexible, though with little

automation. Nevertheless, now that parts

with large and even very large production

runs are being outsourced, the trend in the

supply industry is also moving toward

linked production systems.

The final table (Fig. 8) provides an analy-

sis of some of the criteria used to compare

transfer lines and agile systems. However,

when making a decision in favor of one or

the other, these criteria must be individual-

ly weighted and, if necessary, supplemen-

ted with further information.


31

Extractors for a production plant with automatic,quick-acting clamp closure (Fig. 1)

Dipl.-Ing. Jörg-Peter Körner,

Dipl.-Ing. Michael Bork,

Dipl.-Ing. Heribert Dierkes,

Dipl.-Chem. Dr. Peter Nünnerich,

Dipl.-Ing. Volkmar Steinhagen

New applications of high-pressure extraction

32



1 Introduction

Uhde Hochdrucktechnik GmbH (UHT)

designs and manufactures a wide range of

equipment for high-pressure applications.

Its products include autoclaves, reactors,

heat exchangers, high-pressure pumps,

valves and fittings, flanges and piping. UHT

is a long-established market leader in the

engineering and production of equipment

such as LDPE tubular reactors, high-press-

ure chemical pumps and high-pressure

extraction plants.

For high-pressure extraction with

supercritical fluids, depending on indivi-

dual project requirements UHT supplies

individual high-pressure units, entire pilot

plants or complete production scale plants

as well as the required process parameters

(Fig. 2). The tasks performed by UHT

include planning, safety design and process

engineering, production, assembly and

commissioning as well as operator training.

Much of the development activity at UHT is

devoted to developing new fields of applic-

ation and designing complete extraction

processes.

2 Supercritical fluids

Supercritical fluids are substances or

mixtures under conditions of pressure and

temperature that exceed the critical point.

The critical point represents the end point

of the vapor pressure curve, beyond which

no distinction is possible between the liquid

and gaseous state (Fig. 3). As an example,

an increase in pressure will produce no

condensation. The material properties are

between those of liquids and of gases

(Fig. 4).

This particular combination of material

properties is utilized in extraction, since a

large mass transfer capability exists at

quasi-liquid densities and dissolving power.

A great variety of substances, such as

N2O, C2H6, C3H8, Xe, CO2 etc., can be used

for supercritical extraction (Fig. 5). CO2 is

most commonly used for extraction in

industrial applications due to the following

advantages:

� Low viscosity � Physiologically harmless � Environmentally friendly � Nonflammable � Economic� Readily available

3 High-pressure extraction usingsupercritical gases

Extraction refers to the separation of a

mixture of substances into its constituent

components using appropriate solvents.

Since some low-boiling organic solvents

are toxic, supercritical CO2 is now frequent-

ly used in the extraction of natural sub-

P,T phase diagram of carbon dioxide (Fig. 3)

Industrial equipment for the extraction of spices (3 extractors 500 l each, extraction pressure 440 bar(Fig. 2)


33 New applications of high-pressure extraction

stances. The low critical temperature of

31° C allows especially gentle treatment of

the natural substances. The dissolving

power can be adjusted over a wide range

by varying the pressure and temperature.

High-pressure extraction is used both for

solid and liquid raw materials and offers

a gentle process that can produce pure

extracts in a few process steps.

The extraction of solid raw materials is

performed in a batch process, while liquid

raw materials are extracted continuously

in a countercurrent column.

4 High – pressure extractionprocess

Fig. 6 shows a simplified process

diagram. Liquid CO2 from the collecting

vessel D is compressed by a pump P to the

extraction pressure and transported

through the heat exchanger E 1 (where it is

heated to the extraction temperature) to an

extraction vessel or an extraction column

C. En route through the extraction vessel/

column, the extractable substances are

dissolved in the CO2, which then flows to

the separator S. By adjusting the pressure

and/or the temperature, the dissolving

power of the CO2 is reduced in the separa-

tor, causing the dissolved substances to be

precipitated as an extract. Extract fractions

of various compositions can be obtained in

a multistage separation process. The sub-

critical gaseous CO2 from the separator is

liquefied in the condenser E 3 and collect-

ed in the collecting vessel, from where it

reenters the cycle. In extracting solid

materials, the use of several extractors

allows virtually semi-continuous operation.

This process is used, for instance, to

produce extracts of spices, hops, herbs

and blossoms for the food, cosmetics and

pharmaceutical industries, and to refine

raw materials. Examples include the

decaffeinating of coffee and tea, pesticide

removal from crude plant extracts, cholest-

erol removal from animal products, and

solvent removal from synthetic products.

Typical extraction conditions fall into the

range between 35° and 80° C at pressures

of up to 600 bars. The capacity of the

extractors varies from a few milliliters on a

laboratory scale to several cubic meters on

an industrial scale. Fig. 2 depicts the

extractors of a commercial high-pressure

extraction plant.

In view of the diverse opportunities for

the application of high-pressure extraction,

UHT maintains numerous contacts with

various research institutions and partici-

pates in research projects, some of which

receive public support. UHT also develops

customer-specific applications.

Comparison of the physical properties of gases, supercritical fluids and liquids(Fig. 4) Comparison of the critical data of various substances (Fig. 5)

Process diagram of an extraction plant for solid materials (Fig. 6)

Media Density Viscosity Diffusionr[g/cm3] h [mPa�s] coefficient

D11[m2/s]

Gases 0.6�10-3 – 2�10-3 10-4 – 5�10-5 1�10-5 – 4�10-5

Supercriticalfluids 0.2 – 1.0 10-4 – 5�10-5 2�10-8 – 7�10-8

Fluids 0.6 – 1.8 1 – 50 2�10-10 – 2�10-9

Fluids critical critical Remarkstemperature pressure

Tc[°C] Pc[bar]

Carbon Dioxide, CO2 31.1 73.8

Dinitrogen monoxide, N2O 36.8 74.0 instable

Xenon, Xe 16.8 58.0 expensive

Ethane, C2H6 32.4 48.8 inflammable*)

Ethylene, C2H4 9.4 50.4 inflammable*)

Propane, C3H8 36.8 42.5 inflammable*)

Water, H2O 374.1 220.5 high temperature,corrosive

*) inflammable and undesirable fluid residues in extract and raffinate

34



5 Extraction of liquid-containingpolymer components

The German Ministry for Research and

Technology (BMBF) financially supports a

research consortium that is studying the

recycling of liquid-containing polymer

components. The project partners are the

Fraunhofer Institute for Chemical Technol-

ogy (ICT), Nehlsen-Plump GmbH & Co. KG,

Pongs und Zahn Plastics AG, Retek Ver-

wertungsgesellschaft mbH & Co. KG, Tank

Schuler GmbH, TI Group Automotive

System Technology Center GmbH, Uhde

Hochdrucktechnik GmbH and Werit Kunst-

stoffwerke GmbH & Co. Their individual

responsibilities and interfaces are shown in

Fig. 7. The Fraunhofer ICT is responsible

for the overall coordination of the project.

This project is focused on the recycling of

plastic fuel tanks and plastic fuel oil tanks

(Figs 8 and 9) made of high-density poly-

ethylene (HDPE). At present, a volume

of about 11,000 metric tons per year of

scrapped plastic fuel oil tanks and fuel

tanks is generated. By 2015, an annual

volume of about 20,000 metric tons is

expected. Today these plastics are usually

burned or discarded as landfill. Dismantled

fuel oil tanks are removed by local disposal

companies. During scrapped-car recycling,

plastic fuel tanks are transferred with the

shredder light fraction to landfill sites. But

since the plastics are polluted by hydro-

carbon diffusion during use, these

conventional methods of disposal must be

considered problematic.

The hydrocarbon pollutants also prevent

direct reuse of the plastics, since they

impair the mechanical properties of the

HDPE, and toxic or explosive emissions can

occur during reprocessing. Moreover,

incomplete removal of the impurities would

result in odorous secondary polymer

products.

As a part of this research project, a

comprehensive analysis is being conducted

of the scrapped liquid-containing polymer

components to quantify and evaluate the

pollutant and interferent contents. A divers-

ity of processing methods are being

brought to bear to produce high-quality

recycled material which can be readily fed

back into the production process.

The removal of pollutants from the

plastic and its reuse contribute to the

preservation of the environment and of our

resources, since the amount of waste

products that must be dumped is reduced

and reusable material is created instead.

The goal of the project is to use the

recycled material in the original application,

so “downcycling” is avoided. As a result,

a new source of materials can be tapped,

disposal costs eliminated, the load on

disposal capacities reduced, and the

environment is protected. This approach

has become increasingly important to the

automobile industry as well, since the

EU directive concerning end-of-life vehicles

and the German law concerning scrapped

vehicles (which become effective in 2002)

mandate rising recycling quotas of the

used materials and limit thermal recycling.

In addition there is reason to expect that

the data obtained in this project – albeit

with modifications – could possibly be

applied to the recycle management of other

liquid-containing polymer components, for

Networked relationships among the project partners (Fig. 7)


Liquid-containing polymer components: used plastic fuel tank (Fig. 8)Liquid-containing polymer components: fuel oiltanks by Werit Kunststoffwerke GmbH & Co. (Fig. 9)

Sample of cryogenically shredded plastic fuel tanks after extraction withsupercritical CO2 at 350 bars / 100° C (Fig. 10)

35 New applications of high-pressure extraction

instance containers made of low-density

polyethylene (LDPE) used to store and

transport chemicals or lubricants.

An essential step in the processing of

liquid-containing polymer components is

the extractive removal of fuel components

that have diffused into the material.

In this application, the sorted and

shredded HDPE material is treated with

supercritical CO2 in a high-pressure

extraction plant.

Essential factors that influence the

extraction result are pressure, temperature,

extraction duration and particle size

distribution of the material to be extracted.

The effect of these parameters is first

determined on a laboratory scale, then the

process is optimized on a pilot scale.

The pilot scale is adequate for obtaining

sufficient quantities of purified HDPE to

examine the suitability for further

processing steps. Fig. 10 shows an HDPE

sample after extraction.

Once the optimum process parameters

have been established, the process

engineering and design of a production

plant begins. These parameters and the

process engineering parameters of the

other reprocessing steps are then com-

bined to provide a comprehensive descrip-

tion of the process including a profitability

review, so that by the end of the project

(January 2004) detailed data will be

available for the evaluation of the entire

material cycle.

6 Summary

High-pressure extraction has been used

successfully for years for the extraction of

natural substances. In addition to these

established uses, an increasing number of

new applications in which extraction is

used to improve the quality of technical

products (such as the removal of solvents

and residual monomers from polymers, or

the removal of production adjuvants) or to

aid the recovery of recycled materials is

being discovered.

The extensive experience gained from

extracting natural substances makes it

possible to develop such new fields of

application quickly and at low risk. Here,

however, success is dependent on close

collaboration between all of the partners

involved in the overall process.

36


Membrane electrolysis – innovation for the chlor-alkali industry

The Chlorine/EDC/VC complex built by Krupp Uhde forthe Qatar Vinyl Company, Qatar. View of the cell hallwith Krupp Uhde membrane cells (Fig. 1)

Dipl.-Ing. Klaus Schneiders,

Dr.-Ing. Albert Zimmermann,

Dipl.-Ing. Gerhard Henßen

37



1 Introduction

A key requirement in the international

plant engineering business is to have first-

rate processes that guarantee the opera-

tors of industrial plants the maximum in

productivity, availability and economy.

To meet these challenges, Krupp Uhde

continually strives to improve and expand

its technologies.

Krupp Uhde has accumulated more than

40 years of experience in building chlor-

alkali electrolysis plants, and is one

of the world’s leading suppliers of this

technology.

2 Technology overview

The first processes for the electrolytic

splitting of common salt for the production

of chlorine and caustic soda were intro-

duced in 1890 in Germany with the use of

the Griesheim diaphragm cell, and in 1897

in the USA with the use of the Castner-Kell-

ner cell, which is based on a mercury

amalgam process.

Worldwide chlorine production based on

these two processes peaked in the 1980s

with an output of about 35 million metric

tons per year. Krupp Uhde has built more

than 80 of the plants involved.

Today both the diaphragm method and

the amalgam process are being phased out

because of their high energy consumption

and their low environmental friendliness.

They are being replaced by the latest

development in chlor-alkali technology:

the membrane process (Fig. 2).

The membrane process not only saves

energy, it also produces consistently high-

grade caustic soda with a high level of

environmental compatibility and safety.

Since the 1980s, Krupp Uhde has built

over 70 plants utilizing the membrane

process. To ensure its continued ability to

supply a world-leading technology in the

future, Krupp Uhde is working intensively

on the continuing advancement of mem-

brane cell technology.

3 Krupp Uhde membrane celltechnology

3.1 The principle of electrolysiswith the membrane process

The raw material of chlor-alkali electro-

lysis is common salt (NaCl). An electro-

chemical reaction according to the formula

2 NaCl + 2 H2O 4 Cl2 + H2 + 2 NaOH

causes Cl- ions to be oxidized to chlorine

at the anode, while water is reduced to

hydrogen and OH- ions at the cathode. To

bring this about, specially prepared pure

brine (Ca2+ and Mg2+ ions < 20 ppb) is fed

into the anode compartment. A cation-

selective membrane separates the cathode

compartment from the anode compartment

(Fig. 3). Only hydrated sodium ions can

pass through the membrane. With the aid

Principle of the Krupp Uhde membrane cell (Fig. 3)

The share of different processes in the 1998 worldwide production of chlorine, and 2003 forecast (Fig. 2)

38



of the electric field, chloride ions are

blocked out very well. As a result, the OH-

ions combine with Na+ ions in the cathode

compartment to form pure caustic soda.

3.2 Cell design

The single-cell element developed by

Krupp Uhde combines the choice of an

optimal material with simple cell mainten-

ance.

The anode half shell of a membrane cell

is made entirely of titanium, the cathode

half shell of nickel. The seal system

consists of a PTFE frame gasket and a

Gore-Tex® sealing strip. The external steel

flange, which is equipped with an electri-

cally insulated bolt arrangement and spring

washers, ensures that the single element

will remain leak-proof throughout its entire

service life (Fig. 4).

3.2.1 Functional description

Pure brine is fed through an external

feed tube and nozzle into the anode half

shell and distributed over its entire width by

the internal brine inlet distributor.

A downcomer plate utilizes the gas lift

effect to produce vigorous internal circulati-

on of the brine. This results in an ideal dis-

tribution of the liquid, with uniform density

and temperature.

A baffle plate is arranged in the upper

portion of the anode half shell and has two

basic functions:

� To supply brine to the membrane and

wet it all the way to the upper rim of the

anode half shell� To separate the chlorine from the brine

behind the baffle plate, allowing the

chlorine gas and the brine to exit the

single element smoothly through the

outlet.

The diluted caustic soda solution is

dispersed across the width of the cathode

half shell by a caustic soda inlet distributor

in the same way as described above for the

brine. The products – hydrogen and a 32%

caustic soda solution – flow from the single

element through an outlet.

Due to the fact that there is only a small

difference in the caustic soda concentration

at the inlet and at the outlet and that hydro-

gen and caustic soda are more easily

separated than chlorine and brine, the

cathode half shell does not have either a

downcomer or a baffle plate.

3.3 The electrolyzer – advantagesof a modular design

The Krupp Uhde bipolar membrane

electrolyzer features a modular design that

provides many advantages. Among other

things, these include low investment costs,

low energy consumption and a long service

life.

The single elements are suspended

within a frame and are pressed together by

means of a clamping device so as to

connect them electrically in series. The

single elements are first bolted and sealed

individually, which provides a very high

degree of operational reliability.

Between 20 and 80 elements can be

connected to form a bipolar stack, and one

or several stacks are connected in series to

form a membrane electrolyzer (Fig. 1).

Single-cell element developed by Krupp Uhde (Fig. 4)

39



4 Progressive development of the cell – solving problemsthrough innovation

The success of the single-cell element is

based on the continuing development and

improvement of cell technology and cell

production, and the application of new

technologies and concepts for chlor-alkali

electrolysis that lead to greater profitability

of the entire plant. Key factors determining

the profitability of the plant and by which

plant engineering companies are assessed

nowadays include low energy consumption

(Fig. 5) combined with high system avail-

ability, flexible production rates, high cur-

rent densities and easy maintenance of the

electrolyzers.

To optimize the process, Krupp Uhde has

developed a new cell design based on the

principle of a single modular element. This

new cell generation can be used for current

densities of up to 6 kA/m2. Key advantages

of the design are:

� Minimized losses of potential� Optimized distribution of concentration

and current density� Improved product quality through acidifi-

cation of the brine supply

Demanding tests of the new cell genera-

tion at Krupp Uhde’s own heavy-duty test

stand in Gersthofen, Germany, underscore

the excellent performance of the new ge-

neration of elements. The almost linear

course of the current/voltage curve up to a

specific current of 8 kA/m2 attests to the

high efficiency of the cell’s internal com-

ponents and the improvements in the new

single element.

5 GDE – the technology of thefuture

The formation of hydrogen in the cells

can be inhibited by using porous cathodes

(Gas-Diffusion Electrodes – GDE) that are

depolarized with oxygen or CO2-free air.

Such electrodes are well known from the

field of fuel cell technology, where oxygen

is likewise reduced in an alkaline medium.

The potential level of the oxygen reduction

results in a substantial decrease in the

thermodynamic decomposition voltage in

chlor-alkali electrolysis, which can result in

energy savings of about 30% (Fig. 6).

The GDE electrolysis cell developed by

Krupp Uhde operates on the falling film

principle. It utilizes a half shell that reflects

the state of the art in chlor-alkali electroly-

sis. The cathode half shell has been newly

developed from scratch but is nevertheless

compatible with the single element design.

A cation-selective membrane separates

the anode compartment from the cathode

compartment. The GDE is located in the

cathode compartment. The side of the GDE

facing the membrane is covered with a

hydrophilic layer, the opposite side with

water saturated oxygen (Fig. 7). The hydro-

philic layer ensures a constant distance

between the GDE and the membrane,

allowing a caustic-soda falling film to form.

Promising performance data have been

obtained in various tests with the falling

film cell patented by Krupp Uhde, which

uses an oxygen-consuming cathode.

Market launch is therefore expected in

2005. This successful development was

made possible by the syntheses of a silver

catalyst at the Krupp Uhde Laboratory in

Ennigerloh, Germany.

Relative total energy consumption of the three electrolysis processes (Fig. 5)

Trend in specific energy consumption and maximum current density in Krupp Uhde membrane technology (Fig. 6)

Principle of the Krupp Uhde GDE cell (Fig. 7)

Market shares of the suppliers of membrane electrolysis plants (Fig. 8)

40



6 Outlook – a strengthened market position

The trend in worldwide production of

caustic soda in recent years, with a capa-

city of 50.9 million metric tons in 1998 and

a projected capacity of 54.7 million metric

tons in 2003 (Fig. 2), underscores the

market potential for improved technologies

in chlor-alkali electrolysis. Krupp Uhde is

the only company in the world that can

supply the full spectrum – from the expan-

sion of electrolyzer capacity to the provision

of a complete turnkey plant – from a

single source. At the same time, a growing

number of existing systems based on

the diaphragm or amalgam processes

are being converted to the leading-edge

membrane technology. Krupp Uhde also

supplies designs for such upgrades that

can help minimize downtime and produc-

tion losses during the conversion.

In terms of market shares for membrane

electrolysis systems, Krupp Uhde has con-

tinually improved its position in recent

years – notwithstanding the strong market

position of Japanese competitors – and

has further strengthened its long-term

position through a joint venture with

Gruppo De Nora (Fig. 8).

In January 2001, Krupp Uhde and Grup-

po De Nora, Milan, agreed to collaborate in

the field of electrolysis. The two companies

intend to pool their technologies and their

R&D know-how so as to be able to offer

even stronger performance to their world-

wide customers in the chlor-alkali industry

for the engineering, construction and after-

sales service of electrolysis plants. The

objective is to optimize the technologies

and further reduce energy consumption.

The partners have already established

Uhdenora S.p.A., a joint venture in Milan.

The new company’s own highly specia-

lized production of cell elements and elec-

trode coatings from De Nora Elettrodi will

enable it to supply an entire electrolysis

plant from a single source. Krupp Uhde

and Gruppo De Nora have accumulated

decades of experience in this field and

have built more than 100 reference sites

worldwide using membrane technology.

They are now represented by subsidiaries

on every continent. Krupp Uhde in Dort-

mund, Germany, is responsible for busi-

ness management of the joint venture.

Through its continuous advances in this

technology, Krupp Uhde has gained a tech-

nological edge and will be able to ensure

its market leadership well into the future.

41


Developing the future in cement manufacturing technology

Four cement production plants in Egypt with an annual productionof 6 million metric tons of cement (Fig. 1)

Dipl.-Ing. Andreas Halbleib,

Dr.-Ing. Uwe Maas,

Dipl.-Ing. Franz-Josef Zurhove

42



1 Definition

The DIN definition of cement goes like

this:

“Cement is a binding agent that sets in

the air or under water and is water-resist-

ant after setting. It essentially consists of

calcium oxide, silicic acid, alumina and iron

oxide. The raw material must be heated at

least to the point of sintering, i.e. the state

just prior to melting (1,400 to 1,450 °C).”

2 Worldwide cementconsumption

Today cement is one of the most

important building materials of all, and our

modern world is unthinkable without it.

Worldwide cement consumption adds up

to approximately 1.6 billion metric tons

annually. China is the largest consumer

with 570 million metric tons, followed by

the US with 110 million tons. Germany

consumed about 35 million tons in 2000.

Fig. 2 depicts cement consumption over

the past 30 years. It shows that the

demand for cement has been increasing by

about 33 million tons per year – and has

been doing so continuously over a span of

more than 30 years. Noteworthy current

developments in the industry include espe-

cially the adaptation of the technology to

ecological requirements by means of emis-

sion-reduction measures and the replace-

ment of primary fossil fuels by alternative

fuels, including refuse-derived fuels (RDF).

3 Process steps in a cementplant

The most important raw materials in

cement production are limestone, clay and

marl. These materials are mined in

quarries and comminuted in a crusher to

the size of gravel. It takes 1.56 tons of raw

materials to produce 1 ton of cement.

The steps in the cement-making process

are illustrated in Fig. 3.

Efficient production of high-quality

cement products mandates that the

production processes be optimally adapted

to the available raw materials. It is not

enough to merely string together a chain of

optimized individual processes – let alone

machines. Success depends on planning

and optimizing the system as a whole, with

due regard to investment and operating

costs.

Process steps in a cement plant (Fig. 3)

The cement-making process takes place

in three main stages: raw materials prepa-

ration, clinker production and cement pro-

duction.

3.1 Raw materials preparation

Raw-materials preparation involves the

following individual steps:

Quarry operations, crusher, prehomo-

genization and storage, transportation and

component metering, analyses and

blending checks, raw meal drying, raw

meal homogenization and storage, plus

metering and conveying materials to the

Worldwide consumption of cement over time (Fig. 2)

43



burning process.

Raw materials preparation begins with

the analysis and evaluation of the quarry

situation and the raw materials. Study and

evaluation of raw material deposits lays the

groundwork for the further process design.

The Polysius Research Center provides the

capabilities of a fully equipped chemical,

mineralogical and physical laboratory for

the examination, analysis, evaluation and

testing of raw materials and fuels. Even if

the available data about the intended raw

materials are limited, these materials can

nevertheless be graded and classified by

means of the extensive statistical data

already stored in the Polysius materials

database. ISAR is a program developed

especially for this purpose by Krupp

Polysius that ensures the optimization of

the raw materials preparation line.

This program is based on decades of

worldwide experience in project planning

and in the operation of cement plants. It

utilizes the chemical and geological

requirements as a basis for quantifying the

interrelationships among the systems used

in raw materials preparation. Hundreds of

materials from different quarries were stu-

died and analyzed to build the ISAR data-

base so it could calculate the overall homo-

geneity of the raw materials.

Krupp Polysius has the capability of

simulating all the different plant and

process configurations to determine the

optimum for each individual project with its

particular materials requirements and

boundary conditions. For instance it is

possible to change the size of the homo-

genization system for a materials prepara-

tion line, such as a blending bed and/or

blending silo. ISAR ensures the optimum

configuration of various types of system

used in materials preparation to suit each

particular type of plant. With regard to the

efficiency of homogenization, an optimized

materials preparation line depends not only

on the properties of the materials but also

on the equipment used. The blending bed,

the type and size of silo, and the preceding

control process (including analytical

methods and the frequency of analyses)

are all extremely important. ISAR

accordingly analyzes both the homogeneity

of the raw materials and the homogeniz-

ation effected by the system.

Fig. 4 illustrates ISAR computation of the

homogeneity characteristics during raw

materials preparation.

State-of-the-art materials handling is

unthinkable without high-tech control and

analysis technology. Krupp Polysius has

Circular blending bed for limestone in a cement plant in Argentina (Fig. 5)

Using ISAR to measure homogeneity characteristics in raw materials preparation (Fig. 4)

The POLAB® AOT quality control system (Fig. 6)

44



therefore developed a new online analytical

system for such applications.

Once they have left the quarry, the next

opportunity for improving the homogeneity

of raw materials presents itself in the

blending beds. At this point in the process,

the POLAB® CNA online analysis system

can be used to ensure the earliest possible

implementation of data concerning the

chemistry and/or homogeneity of the

transferred materials. Continuous analysis

of the entire materials flow after crushing

makes it possible to selectively control the

homogeneity of the materials at an early

stage in the process. Knowing the

composition of the materials delivered to

the blending bed also makes it possible to

adaptively regulate the different

components or material qualities.

Especially in the case of problematic

deposits, this capability can improve the

degree of homogenization so significantly

that the size of the blending bed can be

drastically reduced.

Fig. 5 depicts a circular blending bed for

limestone in a cement plant in Argentina.

Another advance in this direction was

achieved by the introduction of the

POLAB® AOT quality control system

(Fig. 6). This is an analytical system in-

stalled in the vicinity of the raw meal plant

immediately downstream of the raw mill to

sample and analyze the chemical compos-

ition of the raw meal. The composition of

the raw meal is then precisely adjusted by

an electronic controller to ensure optimum

raw meal quality in the raw meal silo.

3.2 Clinker production

Cement clinker is the principal ingredient

of cement. The raw meal that has been

temporarily stored and homogenized in the

silo is fed into the kiln, where it is subjected

to a burning process producing cement

clinker. During the burning process, the

material is heated to temperatures that

reach about 1,450 °C – high enough to

partially melt the material. This sintering

process (the term denotes the coexistence

of solid and liquid phases in the blend of

materials) is a key feature of the clinker

burning process. The partial melting is also

referred to as the melting phase and

promotes the generation of the clinker

phases.

The formation of the clinker phases

during the burning process results from a

number of chemical reactions that occur in

part sequentially, in part simultaneously.

The sequence of these reactions has been

the subject of many studies and is still not

fully understood.

In the early days, clinker was burnt in

annular kilns, later in shaft kilns. Since

about 1900, the rotary kiln has become

increasingly common. This kiln is especially

economical to operate, particularly at high

throughput rates. Another advantage is the

blending of the sintering materials at

higher temperatures. A disadvantage,

however, is poor heat transfer in the

temperature range below about 1,200 °C.

Process steps during which the material

is not yet sintering and in which efficient

heat transfer is accordingly more important

were therefore removed from the rotary kiln

and transferred to more efficient equipment

systems: By implementing a separate

facility for preheating the material (LEPOL®

grate, cyclone preheater) it became

possible to substantially shorten and

redimension the rotary kiln.

In the burning process, calcination

occurs mostly at temperatures below

950 °C. In this temperature range a molten

phase has not yet formed. In the calcinator,

a unit equipped with one or more burners,

as much as 80% – 85% of all CO2 is

extracted from the raw meal even before

the material reaches the rotary kiln. As a

result, the revolving tube can be shortened

even more, or the capacity can be

increased without any change in volume.

In plants without a calcinator, all the

energy in the fuel – and all the combustion

Modern cement plant (Fig. 7)

Developing the future in cement manufacturing technology45


air – passes through the revolving tube. In

precalcining systems, on the other hand, a

portion of the fuel – and potentially a

portion of the combustion air – can first be

fed into the calcinator.

In state-of-the-art cement plants (Fig. 7)

the burning process takes place in three

successive units. The raw meal is heated to

temperatures between 800 and 900 °C,

and the major part of the calcination occurs

in a multistage cyclone preheater-calcin-

ator unit. The material is then heated

further to the sintering temperature and

maintained at that level in the rotary kiln.

The burnt clinker is then generally cooled in

a reciprocating grate cooler with partially

movable and ventilated slats.

The high temperature required in the

rotary kiln necessitates the use of high-

quality and accordingly costly fuels at this

juncture. Even though most of the energy-

intensive calcination has already taken

place in the precalcinator, at least 50% of

the total fuel quantity used in the burning

process is consumed in the rotary kiln. An

exceptionally thorough evaluation of the

rotary kiln subsystem is therefore a

prerequisite for optimized dimensioning of

the system as a whole.

Clinker production is a high-temperature

process ideally suited for the use of refuse

as a fuel. Waste materials can be substit-

uted for the precious and costly fossil fuels

normally used in the cement burning

process. Fuel costs account for about 50%

of all energy costs in cement production.

Cement manufacturers consequently

began early on to search for ways of

reducing these costs.

The 1980s witnessed the first use of old

tires to fuel rotary kilns in cement produc-

tion. In recent years, an increasing variety

of waste products have been added as fuel

sources, and the additional advantage of

being paid for accepting them has become

increasingly important. Today such

refuse-derived fuels (RDF) are considered

very important in the cement industry since

they can meet up to 80% of the energy

requirements in rotary kilns.

To further increase the proportion of very

coarse-grain RDF in the cement-making

process, Krupp Polysius has developed the

preheater (Fig. 8). This is essentially a

shaft reactor, in which such coarse fuels

are fed into a rotary air lock and thermally

converted at very low oxygen levels. This

process essentially results in gasification of

the fuels, whose calorific value is fed into

the cement burning process in the form of

reactive gaseous and coke components.

The preheater makes it possible to triple

the use of very coarse-grain RDF in the

precalcination phase versus customary

amounts.

Even the conventional rotary kiln, which

has been used in clinker production for

over 100 years, still has room for improve-

ment. During the development of the

POLRO® 2-support kiln with its direct drive,

the process engineering and mechanical

engineering experience of Krupp Polysius

was therefore used to produce an integrat-

ed, more advanced subsystem with

enhanced performance. The rotary cement

kiln is the core system of the plant, since

the sintering process determines the

essential properties of the cement product.

The required heating, the chemical

processes involved, and the dwell time in

the sintering zone determine the length of

the rotary kiln, which must exceed a certain

minimum that also depends on the kiln

capacity. At the same time, the flow

velocity of the air and the combustion

gases flowing through the kiln must not

exceed a certain maximum to prevent

excessive carry-through of dust. The layout

of the rotary kiln is accordingly character-

ized by the ratio of its length to its diameter

– its L/D ratio.

State-of-the-art rotary cement kilns are

designed with either two or three supports.

Preheater (Fig. 8)



Each support consists of a live ring – a

hoop that encircles the rotary kiln and is

supported by two rollers. In the past, the

practical L/D ratio of 2-support kilns was

limited to about 12: Accurate meshing of

the ring-gear pinion drive could no longer

be achieved at greater lengths.

Optimum process conditions, however,

generally mandate an L/D ratio of 14 – 15,

which is incompatible with the conventional

2-support kiln. This problem has been

overcome by the development of the

POLRO® kiln. This rotary kiln is turned by a

friction drive that utilizes the live ring and

the rollers. This approach makes it possible

to combine the specific advantages of the

2-support kiln (a statically defined system)

with the required dimensions (L/D 14 – 15).

To ensure 100% contact between the

surfaces of the live ring and the rollers at

all times, a self-adjusting roller station

has been developed (Fig. 9).

3.3 Cement production

To produce cement, the coarse-grained

cement clinker must be finely ground and

combined with a setting regulator. Other

raw materials may also be added at this

point.

The product spectrum of the cement

industry has substantially changed in

recent years. This trend is sure to continue

for economic as well as ecological reasons.

An important aspect is the substitution of

waste products or other materials in place

of cement clinker – either (and preferably)

waste products from other industries or

naturally occurring materials. The first

category includes granulated blast furnace

slag from the steel industry and fly-ash

from fossil-fuel power plants; the second,

natural pozzolans and limestone. Another

option is to use gypsum from flue gas

purification as a substitute for natural

gypsum or anhydride. This substitution

reduces investment and operating costs,

and decreases environmental pollution by

eliminating emissions from the burning

process – in particular the substantial CO2

emissions from the calcining and burning

processes. But that’s not all: Such

substitute materials also endow such

“composite cements” with superior

technical characteristics. Cements contain-

ing granulated slag for instance emit less

heat while setting, experience less shrink-

age and are more resistant to sulfates than

are Portland cements.

The increasing diversity of components

used in cement production also increases

the complexity of cement plants and the

demand for technical know-how in their

design and implementation. Moreover, the

productive capacities of such plants are

Hoisting a mill cylinder onto its sliding support system (Fig. 10)

Tiltable drive station of the POLRO® kiln (Fig. 9)



constantly on the increase. In addition, a

modern plant must be able to produce

different types of cement. In the design of

such plants, several criteria must be

carefully balanced. These include on the

one hand the grinding resistance of the

individual components, the dissimilar

degrees of fineness in the cement, thermo-

dynamic considerations regarding the

drying of wet components, and the grain

size distribution which is so important in

determining the properties of the cement.

Laboratory tests of the grinding resistance

are used in designing the cement grinding

process. Several types of tests are used –

either in combinations or separately as

alternatives. The results are scaled up to

an industrial scale with continually

improving correlations.

Krupp Polysius not only has the process

engineering know-how, it also has the

necessary core equipment to meet the

requirements of the plant operator. In the

context of grinding technology, this equip-

ment includes tube mills, vertical roller

mills, high-pressure grinding rolls and air

separators. These machines have to be

engineered for continual use under harsh

operating conditions. This fact calls for very

high competency in mechanical engineer-

ing, especially the disciplines of drive

technology, bearings and lubrication, wear

protection, and the design of highly stress-

resistant forged and cast components.

Krupp Polysius mills are generally large in

size and high in capacity.

Simulation of separator optimization with the rotor vanes in motion (Fig. 12)

Vertical roller mills are used for cement

grinding and feature a disk diameter of up

to 6.6 meters, forged parts weighing about

150 metric tons, an installed drive power of

4,600 kW, and a gas flow of 600,000 cubic

meters per hour.

Ball mills are used with a drive power of

up to 9,000 kW in the cement industry and

with more than 15,000 kW in the ore

industry. For loads of up to 12,000 kN per

bearing, these mills are mounted on

hydrodynamic runners. Fig. 10 shows a

large mill cylinder being hoisted into

position on such runner bearings. A unique

software simulation was created especially

for this development and proven in

industrial tests. As a result, it was possible

to reduce the dimensions of the bearings

and live ring, and to increase the reliability

of the operation (Fig. 11).

For energy-saving pressure comminu-

tion, Krupp Polysius uses high pressure

grinding rolls with throughputs exceeding

1,000 metric tons of material per hour. The

rollers were engineered in collaboration

with forging companies to withstand sus-

tained operation without fatigue, even

Computational simulation of the live ring of a mill cylinder (Fig. 11)



under the required high grinding pressures.

This technology has proven itself in many

years of industrial use, and is an exclusive

feature of Krupp Polysius machines.

Advanced development in process

engineering will be supported by

experiments at technical universities as

well as by cutting-edge simulations of

multiphase flows encountered in the plants

and machines (Fig. 12). By combining

different processes, it is possible to over-

come the limitations of individual processes

and gain entirely new insights. As a case in

point, lab-scale and industrial-scale tests

have demonstrated that the energy

efficiency of the comminution process in a

ball mill can be substantially improved:

Quite remarkable when one considers that

the ball mill uses technology developed

more than a century ago.

4 Outlook

Due to the excellent properties of cement

as a building material as well as its

acknowledged ecological soundness, the

diversity of available types of cement will

continue to grow, and application-specific,

high-performance products will enter the

market.

These trends will require cement plants

with great flexibility, excellent quality

assurance and a high degree of automation

(Figs 13 and 14).

Reducing investment and operating

costs, enhancing quality, and continuing

the improvements in environmental

protection will be among tomorrow’s

challenges. The use of secondary raw

materials both as alternative fuels and as

cement ingredients will be part of these

challenges.

Cement production plants already exist in

which 80% of the heating energy is

generated from alternative fuels. A rotary

tube kiln for instance can burn more than a

million old tires per year, which saves

12,000 metric tons of coal.

State-of-the-art control stand with POLCID® NT process control system (Fig. 13)

POLAB® AMT robotically supported laboratoryautomation system (Fig. 14)

49


Krupp Canada supplies the world’s largest downhill conveyor system

Transfer station between first and second downhill conveyor section (Fig. 1)

Dipl.-Ing. Christof Brewka,

Dipl.-Ing. Martina Shehata, MSc, P. Eng.

50



1 Introduction

When the Chilean mining company Mine-

ra Los Pelambres decided in the mid

1990’s to upgrade the production of its

copper mining operation, a daunting diffi-

culty arose: How would it be possible to

transport 127,000 tons of copper ore per

day from the mine site located high in the

Andean mountains down steep mountain

slopes to the concentrator plant? Belt con-

veyors present the only economical means

of transportation, however, no downhill

conveyor system of this magnitude had

ever been attempted. Preliminary studies

showed that the boundaries of belt con-

veyor design would have to be pushed to

new limits to make this undertaking poss-

ible. Minera Los Pelambres turned their

attention to the leading conveyor designers

and, in the summer of 1997, awarded the

contract to Krupp Canada, a subsidiary of

ThyssenKrupp Fördertechnik, located in

Calgary, Canada. Krupp Canada was now

presented with the unique challenge to

build the world’s largest downhill conveyor

system.

2 The Challenge

The Los Pelambres project is the latest of

several Chilean copper mega-projects,

which have unfolded in that part of the

world since the late 1980’s. Different to

most other Chilean copper operations,

which are primarily located in the high

plains of the country’s northern desert, the

Los Pelambres mine is nestled on a moun-

tain ridge, about 150 kilometers north of

Santiago and only a short distance away

from South America’s highest mountain

peaks (Fig. 2).

The mine site lies at an elevation of

approximately 3200 m above sea level,

some 1600 m above and 12.7 km from the

concentrator plant. Flanked by towering

rock faces and constantly exposed to

rockslides, the only road from the concen-

trator to the mine follows an ancient Inca

foot trail.

The weather conditions at the mine site

vary greatly from the ones at the concen-

trator. Precipitation at the mine falls mainly

as snow and can reach a maximum accu-

mulation of 3 m in a 24 hour period, while

the concentrator site (Fig. 3) sees milder

conditions with precipitation mainly as rain.

Crusher discharge conveyor with mine in background (Fig. 2) Conveyor section 3 and concentrator stockpile building (Fig. 3)

Both areas are susceptible to frequent

electrical storms and avalanche hazards

are present for elevations above 2000 m.

Considering the hostile environment it

became clear that most drive stations and

most of the conveyor length would have to

be built underground and routed through

tunnels to avoid the constant exposure to

snow and rock avalanches.

Besides the obvious environmental con-

cerns, another design factor became more

and more prevalent: A downhill conveyor

system of this magnitude requires an en-

tirely different approach to conveyor design

than a horizontal or uphill system. The

potential danger of a conveyor run-away

under load makes safety the highest

design priority. A loss of control over the

conveyor could result in a catastrophic

system failure and subsequently lead to the

collapse of tunnel sections, to endanger-

ment of human lives, to extensive material

damage, and to extended loss of produc-

tion.

51



3 The Conveyor System

Copper ore is blasted from its rock bed,

then loaded by hydraulic excavators onto

large mine trucks, capable of transporting

up to 300 tons of ore in one load. The mine

trucks travel a short distance to the primary

crushing station located just outside the

mine. A gyratory crusher breaks the rock to

pieces of less than 300 mm size, i.e. small

enough to be conveyor transportable. A

discharge conveyor, 3 m wide and 120 m

long, receives the material from the

crusher and dumps it onto the 72,000 ton

capacity mine stockpile (Fig. 4). Four belt

feeders are located underground below the

stockpile to reclaim the ore at a precisely

determined rate and load it onto the down-

hill conveyor system.

The downhill conveyor system consists

of three conveyor sections: Section one

has a length of 5967 m, section two is

5337 m long, and section 3 measures

1446 m, with a total elevation drop for all

three flights of 1307 m (Fig. 5). All con-

veyor belting has a width of 1800 mm. The

subdivision of the conveying distance into

shorter sections became necessary, since

no conveyor belt would be able to with-

stand the belt tensions generated in a

single flight. Still, the belt force determined

for the first two conveyor sections necessi-

tated the strongest conveyor belt ever

employed. The drive of each conveyor is

positioned at the tail end, where the belt

tensions and thus the traction forces

between the belt and the pulleys are at

their respective maximums.

To provide protection from the harsh

environment, the drive station for section

one, measuring 45 m long by 16 m wide

by 19 m deep, is fully underground, with its

concrete roof at grade level. Only air inta-

kes protrude above the grade level, which

can be easily sacrificed to snow or rock sli-

des (Fig. 4).

The conveyor system is routed inside a

tunnel driven into the mountain (Fig. 6) and

emerges only for the last 500 m before ter-

minating in the concentrator stockpile buil-

ding. The conveyor end is equipped with a

shuttle car, allowing the conveyor discharge

point to be moved 62 m back and forth and

thus forming a longitudinal stockpile of

560,000 tons capacity inside an A-frame

pile shelter (Fig. 3).

Over 12 km of the conveyor system runs inside a tunnel (Fig. 6)

Mine ore stockpile and roof of first drive station with cooling air intakes (Fig. 4) Technical specifications (Fig. 5)

Conveyor tail end with drives and pulley (Fig. 7)

52



Moving at a speed of 6 m/s, the con-

veyor system transports up to 8,700 tons

of copper ore per hour. The 12.7 km jour-

ney from the mine to the concentrator lasts

some 35 minutes. At any one moment, up

to 5,100 tons of copper ore are loaded on

the conveyor system, exerting a pulling

force of up to 3,300 kN onto the belt.

In the loaded condition the motors of the

three overland conveyors act as genera-

tors, and for the fully loaded conveyors

25,000 kW of power are fed back into the

grid. As the belt load decreases, the power

generation drops to zero at some 15% of

belt loading. At lower belt loading rates, the

conveyor drives consume power to over-

come friction within the system. In this

case, the drives are no longer acting as

generators, but as motors.

4 The Drive System

The downhill conveyors are driven by a

total of ten individual drives units of 2,500

kW each. Four drives are installed on each

of sections one and two, and two drives on

section three. The two stage helical bevel

reducers, custom designed for the applica-

tion, are the world’s largest conveyor redu-

cers. The conveyor pulleys, at a diameter

of 2500 mm, likewise are the world’s lar-

gest. The mechanical brake system is com-

prised of 13 disc brakes, each with a rotor

diameter of 2,500 mm (Fig. 7 and Fig. 8).

The power and control system of the

downhill ore conveyors represents the

latest and most innovative state-of-the-art

technology. The power distribution system

for the ore conveyor system consists of 23

kV power centers located on each conveyor

substation. The ten 2500 kW squirrel cage

induction motors are controlled by adjust-

able frequency inverters with vector control

(AFD). With this drive system, the closed

loop speed control with secondary closed

loop torque control allows a defined initial

starting and stopping torque to be applied

to the conveyor belt at all operating conditi-

ons. This inverter drive system further

ensures that the tension forces in the con-

veyor belts are kept to a minimum. In addi-

tion, this means minimized mechanical and

dynamic stresses to the equipment and

structures by a step-less smooth adjust-

ment of torque and speed. The inverter

drive systems are equipped with braking

choppers, braking resistors, and UPS to

maintain their normal stopping capabilities

for a short time in case of line/power failure.

The conveyor control system is linked to

the overall DCS (Digital Control Station)

system and is executed by three pro-

grammable logic controllers (PLC) and

several remote I/O (Input/Output) stations.

The PLCs are interconnected by an indu-

strial open network (H1 network) used for

interlocking, diagnostic and operator con-

trol as well as for video and telephone

communication. The H1 network informa-

tion is carried between the substations and

the operator control rooms over a redun-

dant fiber optic network (OTN network).

Two local profibus networks are used in

each substation. The first network is used

to interconnect the AFD drives and the

PLC. The second network is used to

Drive station of first downhill conveyor section. In foreground 2500 kW reducers, brakes and pulley (Fig. 8)

Krupp Canada supplies the world’s largest downhill conveyor system53


connect the PLC to its remote I/O modules,

the maintenance workstation, and local

operator interface terminals.

The entire downhill ore conveyor system

is operated from four supervisory computer

stations (HMI - Human Machine Interface)

located in various control rooms. All four

HMIs communicate to all the PLCs via the

H1/OTN network. All HMIs have monitoring

and control capabilities. Furthermore,

advanced help and diagnostic information

is available through the use of a separate

interactive help file system working in con-

junction with the supervisory system

(advanced help function). The control func-

tions of each station are protected with

multi-level passwords.

Each substation is equipped with a main-

tenance workstation for local and manual

control and status information of all equip-

ment. A small operator interface is also

provided at each substation for basic sta-

tus information.

The PLC system, the central nerve

system of the conveyor, constantly moni-

tors all vital conditions of the equipment.

Should an abnormal condition be detected,

the computer selects and initiates the

appropriate reaction. The reactions can

range from a simple warning signal to the

operator for minor problems to an emer-

gency conveyor stop for more serious con-

ditions.

5 The Safety Levels

Safety has been the highest design prio-

rity. An elaborate control philosophy has

been developed and incorporated into the

control system. To prevent a conveyor run-

away, five levels of safety have been built

into the system in order to react to any

possible condition or malfunction (Fig. 9).

Level 1

In the case of a normal stop command,

or a minor malfunction, the adjustable fre-

quency drive (AFD) controlled electrical

motors bring the conveyor to a stop, follow-

ing a predetermined 70 second S-curve.

Level 2

In case of a failure of the power network,

which may for example occur as a result of

a lightning strike, the motors are isolated

from the external power grid by the “AFD

choppers”. The electrical energy is now

diverted into large resistor banks and dissi-

pated into heat. A battery back-up system

provides the necessary power for the con-

trol system.

Level 3

In the case of a malfunction to the AFD

system itself or the electrical motors, the

conveyor disc brakes will be utilized to stop

the conveyor. During the stopping process,

the speed of the conveyor is constantly

monitored and the brake force is adjusted

accordingly. This allows the conveyor to be

stopped following the same smooth speed

ramp as in levels 1 and 2.

Level 4

In the case of a PLC system malfunction,

or if an extreme overspeed condition is

detected, the brake calipers will engage

immediately by gradually releasing the

pressure of the hydraulic control system.

With decreasing line pressure, the caliper

springs apply increasing breaking force.

Different to the lower stopping levels, the

brake time is dependent upon the actual

belt loading conditions.

The five levels of braking (Fig 9)



Level 5

In the event of a severe failure to the

brake’s hydraulic system, or should an

overspeed condition occur during level 4

braking, the brake calipers are released

using the so-called quick-dump method.

The hydraulic pressure is now released

using valves located directly at the brake

calipers. The brake force will thus be

applied in full and immediately.

6 The Conveyor Belt

From the onset of the project it was

obvious that a new approach needed to be

taken with regard to the belt design. Con-

ventional belt safety factors and the high

belt forces would combine to a belt

strength requirement far beyond tested belt

constructions. More than the belt itself, the

belt splices are of great concern due to

their tendency to fatigue. Weighing all the

factors a ST-7800 belt was selected, which

pushed the previous belt strength record by

10%. At the same time, the belt safety fac-

tors were lowered from the conventional

values to 5.4 for nominal operation and 4.0

for emergency stopping. A rigorous testing

program was established as a precondi-

tion. Belt samples were manufactured and

tested for the dynamic fatigue strength

according to DIN 22110 in a revolving loop

test rig. Ultimately it could be proved that

the selected belt including the belt splice

could withstand more than 10,000 load

cycles at over 50% of the ultimate braking

strength of the belt. As conveyor belts in

general follow the Woehler fatigue theory, it

can thus be concluded that the belting will

be fatigue safe for belt safety factors better

than 2.

As an additional safety precaution, a

splice monitoring system has been devel-

oped and installed. This system measures

the length between embedded markers on

either side of the belt splice. Each time a

splice passes by the sensor, the splice

length is measured and compared to its

reference value. The measured value is

then normalized for temperature and belt

loading. In case the measured value devi-

ates from its expected value, an impending

splice failure may be the cause. The belt

can now be safely stopped and the splice

can be inspected. With this method, cata-

strophic belt rips can be avoided.

7 Structural Design

The combination of environmental condi-

tions such as high earthquake loads to

UBC zone 4, extreme snow loads for the

equipment at the mine site, the potential of

large differential settlements of foundations

due to unstable ground conditions, and

large material loads as well as high belt

tensions, set the parameters for the struc-

tural design of the conveyor system.

For the crusher discharge conveyor

(Fig. 2 and Fig. 4) a snow load of 7 kN/m2

had to be considered, together with the

material load of 14,000 t/h copper ore.

The connections to the foundations were

designed to accommodate 50 mm differen-

tial settlement, and allowances were made

in the support structure to monitor settle-

ment and to jack the conveyor structure to

compensate for excessive settlements.

The 12.7 km length of the conveyor

required careful optimization of the con-

veyor modules. The modules had to be

economical to fabricate as well as to install

in the long conveyor tunnels (Fig. 6). The

modules were optimized in 9m sections,

resulting in a total number of 1415 con-

veyor modules. The modules had to be

designed for the steep downhill sections

and the high earthquake loads, and had to

Forces acting on conveyor drive structure (Fig. 10)



allow for adjustment to the terrain as well

as to accommodate the temperature

expansion over the length of the conveyor.

The drive structures, which support the

drive and brake systems for the conveyors,

and also incorporate a take-up carriage to

release the belt tension for belt splicing and

maintenance, are subjected to very high

belt forces and braking forces (Fig. 10).

Finite element analysis was used to deter-

mine the critical stress values, the stress

distribution, and the loads to the concrete

foundation (Fig. 11). To anchor the drive

stations against the resultant pulling force

a combination of pre-stressed Dywidag

anchor bolts, conventional cast-in-place

anchor bolts and a concrete thrust block

was used to provide a redundant anchora-

ge system to the concrete foundation. This

in turn required multiple analyses to design

the structure and anchors for different pos-

sible support conditions and multiple load

paths.

8 Conclusion

The challenge, which presented itself to

the engineering team at the beginning of

the project, was overcome by the combi-

ned effort of all engineering disciplines

involved. The conveyor system has been in

operation since December 1999. The ope-

rating experience shows that the ambitious

design capacities were exceeded, and up

to 140,000 tons of copper ore per day

have been moved by the system.

Finite element analysis: Stress contour plot corresponding to force diagram (Fig. 11)

56


SVI Noord-Brabant sewage sludge incineration plant, Netherlands

SVI Noord-Brabant sludge treatment plant, Netherlands (Fig. 1)

Burckhard Bussmann,

Dr. Jürgen Schilling


57 SVI Noord-Brabant sewage sludge incineration plant, Netherlands

1 Background

Sludge is an inevitable by-product of

wastewater purification, and its quantity

increases in the course of advanced

wastewater treatment steps in sewage

treatment plants. Recycling is only possible

to a limited degree and at best after

expensive pretreatment.

The primary aim of sewage treatment

plants, which treat sewage of human and

industrial origin (polluter), is to release a

clean effluent into natural surface waters

(receiving water) and to remove the

pollutant load in as concentrated a form as

possible as sludge. The good quality of the

surface water in Central Europe indicates

that modern sewage treatment plants are

achieving this primary goal. However, the

same cannot be said of the sludge. One

look at its basic structure reveals the

reason:

The anhydrous part (the dry matter –

DM) of the sludge contains not only mineral

substances, which mainly accumulate

during the sedimentation of the suspended

particles in the water purification process,

but also approximately twice the amount of

organic matter. This consists largely of the

dead microorganisms which, on the one

hand, were mainly responsible for

successful purification during the biological

treatment step but, on the other hand, are

difficult to clear of adhering water. The

resulting sludge has a high or very high

water content, depending on the degree

of further treatment. The figures in

Fig. 2 illustrate the ratios based on the

SVI Noord-Brabant project.

In addition to these technical boundary

conditions, ecological and economic

requirements significantly influence the

choice of sludge disposal procedure, the

most common versions of which are briefly

outlined.

� Spreading liquid sludge on agricultural

land for the fertilizers and soil improvers

it contains is now only applied on a small

scale in rural areas. This method is

criticized – even by advocates of

biological recycling – because potential

contaminants that have already been

collected are redistributed over a large

area. � The disposal of mechanically dewatered

thickened sludge in landfills is subject to

increasingly stringent requirements, for

example sealing against groundwater,

and the collection and treatment of

leachate. Broader waste regulations due

Main flows in the SVI Noord-Brabant sewage sludge treatment plant (Fig. 2)

58



to take effect shortly will prohibit this

formerly inexpensive method of disposal

in the future.� Mechanically dewatered sludge –

usually also thermally dried – can be

burnt in specially constructed

incineration plants, and to some degree

also by co-incineration of fully dried

sludge, for example in cement kilns or

power plants.

Against this background the five water

associations of the Dutch province of

Noord-Brabant founded the company N.V.

Slibverwerking Noord-Brabant as part

of a project to develop a central sludge

incineration plant, the world’s largest and

most environmental friendly of its kind

(Fig. 3). ThyssenKrupp EnCoke emerged

successful from the international tendering

process and, in cooperation with

subsidiaries Thyssen Still Otto Nederland

B.V. and Blohm + Voss Industrietechnik,

was the leading industrial partner in all

phases of project development and

implementation.

2 Basis of the design

In the first step, the specifications were

defined in close coordination between the

client and the engineers. The properties

and quantities of the sludge from the

individual sewage treatment plants in the

area were tested for their combustion and

pollutant emission indices, and assess-

ments were made of expected future

changes. Special attention was given to

finding the ideal combination of buffer

capacity, line throughput capacity and

installed reserve to meet seasonal and

meteorological fluctuations (rain) in sludge

volumes. This resulted in the following

nominal plant capacity, based on the dry

matter (DM) of the sludge:

� incinerator capacity

(based on DM): 3.8 tons per hour� annual plant operating hours

(continuous): 8,760 hours per year� number of working incineration lines: 3� nominal capacity

(based on DM): 100,000 tons per year� installed reserve – number of standby

incineration lines: 1

The standby line, provided in addition to

the three working lines to accommodate

fluctuations in sludge volume and already

included in the annual tonnage of 100,000

DM, adequately compensates for down-

times of individual incineration lines due to

faults or maintenance work and ensures

that overall incineration capacity is available

at all times.

The design of the environmental

protection equipment was based on the

BATNEEC philosophy (best available

techniques not entailing excessive cost).

This calls for the use of the best available

technology, but not at any price. For

example, the dream of zero emission must

not be bought with unreasonably high

energy input. The resulting design satisfies

statutory and official thresholds even when

incinerating sewage sludge with maximum

pollutant loads, and with normal input is

well below the already extremely low

emission limits applied in the Netherlands.

One result of the “approval planning” project phase (Fig. 3)

59


Schematic of an incineration line (Fig. 4)


With regard to the quantities and properties

of the unavoidable residues, the plant is

designed to maximize the quantity of

reusable residual material and minimize the

amount of waste requiring disposal.

3 Process

The dewatered sludge from the various

sewage treatment plants is incinerated

centrally at the SVI Noord-Brabant plant in

a fluidized bed incinerator (Fig. 4). With an

installed capacity of 133,000 tons of dry

material per year for all lines, this is the

largest plant of its kind in Europe. The four

incinerator lines (one of them a standby

line) each have a capacity of 3,800 kg/h of

dry sludge material to ensure full avail-

ability.

The key process steps of the plant are:

� common sludge storage bins with a

volume of 5,600 cubic meters � four separate process lines, each

including:

– 2 disc dryers for sludge pre-drying,

heating area 250 square meters per

unit

– incineration in fluidized bed incinerator,

nominal size (air distributor area)

10 square meters

– steam boiler for recovery of heat,

capacity: 11.1 tons per hour at 10 bar

and 180°C

– triple-field electrostatic precipitator

– 2-stage flue gas scrubber to remove

sulfur and chlorine compounds

– fabric filter system to remove ecotoxic

pollutants (for example, mercury)� common infrastructure, auxiliary

equipment and residual material

treatment facilities

3.1 Sludge delivery and storage

The dewatered sludge with an average

DM content of 24% is transported by road

to the incineration plant, where it is

dumped into deep storage bins. A fully

automatic crane system mixes the different

types of sludge and charges the process-

60



ing lines by means of mechanical

conveyors and intermediate silos. Foul

smelling air, which forms over the sludge in

the closed storage bins, is extracted and

fed to the incinerators. A biofilter is on

permanent standby to supplement these

arrangements, especially when several

incinerators are shut down.

3.2 Sludge drying and vaporcondensation

Steam-heated disc dryers are used to

increase the dry solid content to approx-

imately 45%. The steam is generated

using waste heat from the incineration

process. The vapors arising from the dry-

ing process are condensed, stripped of

ammonia by steam and fed to a sewage

treatment plant. Non-condensable residual

vapors are fed to the incinerator for

burning.

3.3 Sludge incineration

The pre-dried sludge is burned without

any additional energy (fuel) in a refractory-

lined fluidized bed incinerator using the

ThyssenKrupp EnCoke process (Fig. 6).

The principle: air enters the reaction

chamber through nozzles in the distribution

plate to achieve intense fluidization of the

fine-grain, inert material (sand). The

sewage sludge falls into this fluidized bed

from above and is fully incinerated at

temperatures of approximately 870 °C.

Lime is added to the incinerator to signific-

antly decrease the SO2 content of the flue

gas. The already low NOx levels in the flue

gas are reduced further by a non-catalytic

aqueous ammonia injection system.

The distribution plate plays a significant

role in the fluidized bed process. It closes

the incineration chamber at the bottom,

supports the fluidized bed, and through its

nozzles ensures good air distribution, which

is a prerequisite for optimal incineration

with a low excess air level. Normal opera-

ting conditions and especially any cases of

expected breakdown or even mishap lead

to extra loads. The most important types of

these extraordinary stress situations can be

characterized as follows:

� Load per unit area of up to 2 tons per

square meter due to the fluidized bed

when not in operation. In operation this

load is relieved by the surface pressure

of the air below the air distributor. How-

ever, this results in cyclic dynamic loads

of several hundred kg per square meter

generated by the turbulence of the fluid-

ized bed.� The temperature load on the system is

determined from the heat of the fluidized

bed as well as the temperature of the

incoming combustion air. It can, in the

case of an emergency furnace shut-

down, be up to 900 °C.� The operating schedule can constitute an

additional load if it specifies frequent

shutdowns (there are plants used in

one-shift operation that start and shut

down again every day). In such cases,

expansion/contraction stresses are

added to the aforementioned loads.� Waste contains corrosives (e.g. chlorine)

or erosives (e.g. kaolin, used in the

paper industry). These substances also

act on the elements of the distribution

plate.

Whereas distribution plates are

conventionally made from solid ceramic

plates, which are generally less durable,

ThyssenKrupp uses a metallic design

comprising several modules. After

intensive consultation with the Group’s

structural analysis experts and steel

specialists, a material was selected that

has proved successful under long-term

exposure to the aforementioned loads in

numerous plants and, in addition, is

inexpensive and readily available: material

no. 4541, (X10 CrNiTi 18 9), also generally

known – even to the general public – as

V2A. Good solutions are even better if they

are simple.

3.4 Energy recovery

The flue gases exiting the fluidized bed

incinerator at approximately 870°C enter a

steam boiler in which they are cooled to

approximately 200 °C, thus generating

saturated steam at 10 bar and 180 °C for

sludge drying and wastewater evaporation.

This simple sounding task is performed

by a complex subsystem comprising not

only the steam boilers but also numerous

elements of the water/steam cycle; the

engineering, design and manufacture of

this subsystem are subject to national and

European rules and corresponding

acceptance tests. This whole area was

Configuration of the sludge drying, incineration andsteam generation systems (Fig. 5)

61



engineered and built by sister company

Blohm+Voss Industrie GmbH, Hamburg.

After joint consideration of the key prop-

erties, an advanced natural-circulation,

angular tube-type water boiler was chosen

with cleaning of the flue gas-side heating

surfaces via ball cleaning.

3.5 Flue gas scrubbing

A triple-field electrostatic precipitator is

provided to remove dust from the flue gas.

The separated dust is discharged and con-

veyed together with the boiler ash to a road

vehicle loading facility.

After cooling in a cross current heat

exchanger, the flue gas passes through a

two-stage scrubber process: an acid spray

scrubber cools the gas and removes HCl,

HF, heavy metals and excess ammonia

from denitrification; and an alkali packed

scrubber with caustic soda removes SO2.

Scrubber slurries are neutralized in the

wastewater evaporation plant to guarantee

that no wastewater is discharged from the

flue gas scrubbing process.

After reheating, the flue gas passes

through a filter system for final cleaning, in

particular to remove mercury. Activated

carbon mixed with hydrated lime is injected

into the flue gas stream as an adsorbant,

which is removed in the downstream fabric

filter.

As with the residue from the wastewater

evaporation, the filter dust is conveyed

to a silo vehicle loading facility for environ-

ment-friendly disposal.

4 Results

The incineration of 417,000 tons of

sewage sludge per year (in the dewatered

condition as delivered) yields the following

residues or products:

� approximately 30,000 tons of fine-grain

ash, which is processed into pellets by a

construction materials company for use

in road construction� approximately 1,000 tons of dry salts

and other wastes from flue gas

scrubbing; this is the pollutant content of

the sewage sludge concentrated to a

minimum and is properly disposed of

Experience from 4 years of service has

shown the plant to meet all expectations

in full. Of the criteria delivering better-

than-expected results, one is particularly

important to the customer:

In practice, the amount of downtime due

to breakdowns was significantly lower than

conservative estimates predicted. This

allowed the plant management to

activate the unused reserves to incinerate

edditional sewage sludge for other

provinces of the Netherlands. Obviously,

this has significantly enhanced the plant’s

economics.

The positive overall impression,

interesting technical details, good func-

tionality, low production costs and high

ecological compatibility of the plant have

shown it to be a wise investment and have

earned great recognition for our company

from experts in the field. This makes the

Noord-Brabant sewage sludge incineration

facility an outstanding advertisement and

hence an excellent reference for Thyssen-

Krupp EnCoke’s fluidized bed technology.

Typical fluidized bed incinerator design (Fig. 6)

fuel feed

freeboard

fluidized bed

air distributor

start-up burner

secondary air

ash removal

combustion air

62



5 Outlook

The plant’s higher degree of utilization

also netted additional benefits to the

plant’s designers and builders.

As stated above, the plant was designed

to operate with three working incineration

lines and one standby. Since the capacity

of the auxiliary plants was designed for

three-line operation, it was only possible to

run all four lines simultaneously for short

periods. In December 1999 the operator

decided to expand the infrastructure of the

incineration plant. NV Slibverwerking Noord

Brabant (SNB) awarded Thyssen Still

Otto Nederland B.V., a subsidiary of

ThyssenKrupp EnCoke GmbH, an order to

increase capacity with the goal of running

permanent four-line operations.

Key to this order was the construction in

a new building of a new evaporator for

wastewater from the flue gas scrubbers.

This building was also used to house

various storage tanks and a hot water

flushing system for maintenance and

cleaning of the entire system. The order

also included upgrading the existing

compressed air supply and naturally also

adapting the process control system to the

new equipment. Test runs for this capacity

expansion were successfully completed in

August 2001.

Installation of heavy machinery (Fig. 7)

63


The frigate Sachsen at sea (Fig. 1)

Dr. jur. Reinhard Mehl

The “Sachsen” – impressions from the sea trials

64


1 Introduction

At around 8:15 a.m. on August 28,

2001 the frigate Sachsen cast off from the

shipyard Blohm+Voss and left for maiden

sea trials. It was on June 13, 1996, some

five years earlier, that the contract had

originally been signed to build three frig-

ates of the 124 class. The general contrac-

tor for the project is the ARGE F124

consortium, which comprises the shipyards

Blohm+Voss GmbH (project leader),

Howaldtswerke-Deutsche Werft AG and

Thyssen Nordseewerke GmbH.

A member of the frigate class F124, the

Sachsen is the largest warship in the

German Navy (Fig. 1). The F124 program

falls under the trilateral frigate agreement

between Germany, the Netherlands and

Spain. At a contract value of around €1.5

billion, it is one of the largest of the Ger-

man armed forces’ procurement programs

currently running and involves some 800

subcontractors throughout Germany as

well as in other NATO countries. For the

participating shipyards, the project involves

around 1.9 million office hours and some

one million construction hours per ship.

The technical specifications of the frigate

are listed in Fig. 2.

2 Technical equipment

The main difference to the previous

(F123) frigate class is that the new vessels

are primarily designed for area air defense

and escort duties. To this end, they have

been fitted with a range of extra equip-

ment, including the newly developed radar

systems APAR and SMART-L as well as

long-range anti-aircraft missiles. Similarly,

the frigates also feature the decentralized

command and weapons control system

FüWES together with the command

deployment software CDS, again a new

development (Fig. 3). Here, processing

requirements are spread across 17 com-

puters connected up by a multiply redun-

dant ATM bus. As such, the system is

capable of simultaneously registering

more than 1,000 potential air targets at

a maximum range of around 400 kilome-

ters. Capable of attacking targets at a

range of more than 100 kilometers, the

new frigate is designed to serve as a

command and control platform. Aside

from its principal anti-air warfare (AAW)

capability, it is also designed for all other

combat operations such as anti-surface

warfare (ASuW) and antisubmarine

warfare (ASW).

Two distinguishing features in particular

determine the outer appearance of the new

frigate: the APAR radar fixed to the forward

mast and the so-called x-form of the outer

skin, which extends down as far as the

C-Deck (Fig. 4). This design of the super-

structure drastically reduces the reflection

of incident radar signals and therefore

gives the vessel stealth qualities. The

design incorporates all the characteristics

of the MEKO concept, as developed by

Blohm+Voss, with regard to modularity,

strength and signatures.

3 Marine systems trials

The sea trials involve comprehensive

tests, with a particular focus on the ves-

sel’s machinery. In addition, initial trials of

the FüWES command and weapons control

system are also being conducted. The

decision to hold relatively early sea trials –

more than a year before the frigate is

scheduled for commissioning (November

2002) – means that there will also be

plenty of opportunity to fine-tune the ship’s

systems under operational conditions and

identify the existence of any possible faults

in good time.

The main emphasis of the marine

systems trials is to test the combined

diesel and gas turbine propulsion system

CODAG. This comprises a gas turbine with

an output of 23,500 kilowatts plus two


Technical specifications of the Sachsen (Fig. 2)

65


diesel engines, each delivering 7,400 kilo-

watts. These are connected up via a

cross-connection gearbox to two operating

shafts, which in turn drive two variable-

pitch propellers (Fig. 5). Unlike the

propulsion system installed in the previous

generation of vessel, this configuration not

only dispenses with a second gas turbine

but is also capable of propelling the vessel

at cruising speed with the use of just one

diesel engine – a feature which markedly

reduces operating costs over the life of the

vessel.

Another installation of particular

significance is the newly developed

Integrated Monitoring and Control System

(IMCS), which is based on a data bus. Via a

total of some 7,000 different monitoring

stations distributed around the vessel, the

IMCS monitors and controls all the various

marine systems on board (Fig. 6). In


on September 9 and dynamic tests of the

radar systems including the use of

Tornadoes and helicopters from the

German Navy on September 6 and 7,

2001. Afterwards, the frigate transferred to

the Skagerrak for a further week of marine

systems trials, before returning to

Blohm+Voss on September 13.

The main emphasis of the FüWES trials

has fallen on the newly developed CDS

software and SMART-L and APAR systems.

As the land-based facilities capable of

testing such a system within the corres-

ponding development plans can only

handle parts of FüWES, the sea trials

provided a first opportunity to see how the

various elements will function together in

their ultimate configuration and under

operating conditions. As such, the trials

also offered a chance to collate data

required for further development of the

addition, the IMCS is equipped with a

comprehensive range of user interfaces

plus a fully automatic malfunction and

damage analysis system. For the purposes

of crew training, the system can be set to

simulate any conceivable malfunction or

damage scenario.

In addition to the vessel’s propulsion

unit, trials will also focus on the onboard

electrical and ventilation systems as well as

all the remaining supply and disposal

systems. These will first be tested and then

presented to the client’s acceptance com-

mission. Aside from the minor teething

troubles always encountered in a project of

this nature, the trials have been very suc-

cessful to date.

Further highlights of the sea trials have

included measurement of the acoustic

characteristics of the Sachsen in waters off

the northern German town of Eckernförde

Block diagram of the command and weapons control system FüWES (Fig. 3)

66



systems. It was for this reason – and to

minimize the risks that problems here could

pose to the program as a whole – that it

was decided to bring the FüWES trials

forward and conduct them at an earlier

date than originally planned.

These initial pre-tests proved exception-

ally successful. For example, the long-

range radar system SMART-L was able to

reliably detect air targets at a range of

around 400 kilometers. Moreover, good

results were also achieved with the newly

developed APAR system.

4 Risk management

A specific feature of the F124 program

was that major elements of the complete

system – i.e. the radar systems,

automation systems and the entire FüWES

software – were developed in parallel with

the construction of the frigates. Despite the

element of risk that such a procedure

involves, it was chosen in order to

accommodate the increasingly shorter

innovation cycles in the IT sector. Without

parallel development, a frigate built

according to definitions established some

eight to 10 years previously would hardly

correspond to the latest technological stan-

dards once it came to be commissioned –

a consequence that is less and less

acceptable given the danger this might

involve in a crisis.

In addition, the costs and risks involved

in certain developments are such that it

was decided to proceed with these on the

basis of a joint international program. It is

then the responsibility of the ARGE F124

consortium to integrate these develop-

ments, together with the CDS software

(which was developed under the responsib-

ility of ARGE F124), into a fully functioning

total frigate weapons system.

A further feature of the project is that the

frigates are being developed and built for

a fixed price that may only be modified in

order to take account of the effects of

inflation or any subsequent modifications

desired by the client.

As such, risk management has played a

major role from the very beginning of the

project. A central pillar of this process was

the establishment of permanent monitoring

procedures designed to ensure that the

various system elements developed can all

be fully integrated with one another. Here,

The frigate Sachsen at sea (Fig. 4)

Functional principle of the CODAG propulsion system (Fig. 5)

67 The “Sachsen” – impressions from the sea trials


a corresponding agreement was signed

before the construction contract between

all the companies involved came into force.

In line with this agreement, the ARGE F124

consortium has been guaranteed access to

all essential documentation and processes,

including those relating to projects

conducted by third-party companies, so

that it is able to monitor the state of

development on a continuous basis as well

as identify any potential inconsistencies.

The independent team specially created

for monitoring purposes is involved not

only in identifying problems in this area but

also in developing appropriate solutions.

Block diagram of the automation system IMCS (Fig. 6)

5 Outlook

At the end of October 2001, the Sachsen

was handed over to her crew and then

moved to Wilhelmshaven. The period until

delivery in November 2002 will feature a

host of further tests and integration work,

involving particularly the highly complex

AAW system. Given the good results

achieved during initial sea trials, the

attitude of all parties involved in the project

is very positive and cooperative — some-

thing that is absolutely essential if the tight

schedule is to be met.

With the launch of the sea trials in

August 2001, the F124 program reached

another major milestone right on schedule

– as has been the case with all the other

important project dates so far.

Work on the two remaining ships in the

F124 program is also proceeding to plan.

In Kiel, dock assembly has just begun on

the frigate Hamburg, while construction of

the third member of the F124 class, the

Hessen, officially started on September 14,

2001 at Thyssen Nordseewerke in Emden.

The procedures adopted for the F124

program have proved their effectiveness.

Despite various problems during the course

of the project, the program still remains on

schedule and within the original budget.

The partners involved in the program have

forged a pioneering path to achieve an

optimal mix of performance, risk and price.

As such, the approach used in the F124

program is well suited to serve as basis for

future naval projects of a similar com-

plexity.

68


Research and testing vessel from Thyssen Nordseewerke

Dipl.-Ing. Martin Braun,

Dipl.-Ing. Achim Hollung

3-D view from starboard (Fig. 1)

Research and testing vessel from Thyssen Nordseewerke69


1 Introduction

On December 12, 2000, a €92 million

contract for the construction of a Class 751

research and testing vessel (FES) was

signed at the German Federal Office of

Defense Technology and Procurement

(BWB) in Koblenz.

The twin hull vessel is to be delivered on

October 31, 2003 after a relatively short

design and manufacturing period. It will

be used to replace two already-decommis-

sioned vessels of the WTD 71 research

station in Eckernförde and the research

vessel “Planet” of the Underwater

Acoustics and Marine Geophysics Research

Institute in Kiel.

The FES will be constructed as a SWATH

(Small Waterplane Area Twin Hull) vessel

and thus represents a technical challenge

for the shipyard. This platform, which is

particularly stable in varying sea conditi-

ons, appears ideal for its future assignment

as a research vessel. It will be used mainly

for basic scientific research, particularly

into the influences of the oceanic environ-

ment on acoustic and electromagnetic

underwater location and communications

systems. After commissioning, the vessel

will initially be used mainly to perform re-

search tasks for the Technical Center for

Ships and Naval Weapons 71 (WTD 71),

for which an array of shipboard equipment

will be provided. In addition, container

spaces will be provided on deck for additio-

nal necessary scientific equipment.

SWATH vessels are characterized by a

relatively wide platform mounted on narrow

struts with minimal waterplane area,

ending underwater in large submersible or

floating hulls similar to submarines. The

small waterplane areas minimize the

impact of sea movements on buoyancy,

design of submarines, making the FES one

of the quietest surface vessels in the world.

(Fig. 2)

� Vessel propulsion by means of electric

motors.� Energy generators positioned on the

main deck, well above the waterline.� All other significant noise generators also

installed above the waterline to avoid

direct transfer of structure-borne sound

to the water.� Where possible, pumps installed jointly

on elastically mounted intermediate

bases.� Electric motors for acoustically relevant

equipment are of multistage design

where possible.

3 Vessel design

The vessel design is shaped by the sea-

keeping requirements.

The decision to construct the FES as a

SWATH was based on BWB research. Pre-

liminary studies defined limits for heavy

physical work at specific wave heights in

the North Sea. Put into words, this roughly

translates as: “given even distribution of

providing platform stability even in heavy

seas and thus significantly reducing restric-

tions on research activities caused by bad

weather (Fig. 1).

2 Principles

The fundamental technical design of the

FES is based on the regulations applying to

commercial vessels. Building regulations

of the Federal Armed Forces are only con-

sidered where appropriate civil regulations

are not available and/or special require-

ments were set by the client.

The FES project is accompanied by the

development – commissioned by the BWB

in May 1997 – of permanent magnet (PM)

excited machines for vessel propulsion and

power supply. These machines have been

supplied in part and were taken into consid-

eration in the technical design of the FES.

The acoustic requirements are based on

the hydro-acoustic tasks which the FES has

to perform and result in underwater sound

limiting curves corresponding to those of

advanced submarines in silent running

mode. These requirements are met

by Thyssen Nordseewerke (TNSW) using

its specialist know-how in the acoustic

General plan side view (Fig. 2)

70



vessel speeds and courses in the defined

sea conditions, the selected limiting criteria

are not exceeded in 75% of all cases.”

Monohull vessels, according to the prelimi-

nary studies, require a design approxima-

tely 2–3 times larger to achieve compara-

ble values.

The shape of the hulls has a key influ-

ence on resistance and damping. The tra-

pezoidal shape selected here (the so-called

“elephant foot”) offers optimum damping.

The hull cross-section tapers continuously

toward the stern and bow, and there is only

an approximately 3 meter long parallel

central section. This shape is costly to

manufacture, but offers significantly lower

resistance than, for example, cylindrical

hulls (Fig. 3).

The forward fins, which each have an

area of approximately 8 m2, can be used to

further improve seakeeping. They are

mounted horizontally and have an opera-

ting range of +/-20°. They are provided to

compensate for any speed-related trim-

ming, which can also be performed by

taking on ballast. The fins are also used for

controlled equalization of pitch caused by

heavy seas. The eight fins are permanently

integrated and serve to improve the

longitudinal stability of the FES.

Another key design criterion is weight.

The weight sensitivity of the FES is

exemplified by the waterplane area. The

entire waterplane area of the FES is approx-

imately 280 m2. Each additional 2.8 tons of

weight results in 1 centimeter more draft. A

planned 72 ton load of research equipment

increases the draft by 25 cm. Consumption

of the planned fuel load of approximately

350 tons results in a change in draft of

1.25 m.

These observations assume that the

masses act at the center of gravity. A one-

sided load causes a correspondingly

greater list. The shape of the waterplane

area, which runs to a point at the hull ends,

allows significant trimming with appropriate

fore or aft loading.

On the FES these effects are countered

using ballast. After a change in loading,

the FES is appropriately ballasted with the

aid of a trimming computer. Over 1000 m3

of volume is available for equalization on

the FES in various ballast water cells.

To get a clear picture of the weight situa-

tion, a weight calculation, like those used

for submarines, is performed during the

engineering phase of the FES.

The steel ship design of the hull is deter-

mined by the prevalent transverse loads.

As in all twin-hull vessels, the transitional

area from the struts to the wet deck is

particularly affected by transverse loads in

rough seas. For this reason, a transverse

frame design has been provided with

500 mm spacing above the platform deck.

The hulls have a longitudinal frame design

with 400 mm longitudinal frame spacing

and 1500 mm web frame spacing.

Dimensioning is based on a global finite

element analysis. In various studies, the

transitions between strut/haunch and

haunch/wet deck were investigated. It was

Bow view (Fig. 3)

� direct drive of the propellers by particu-

larly low-noise electric drive motors,� inclusion of propellers with cavitation at

vessel speeds above 12 knots.

4.2 Diesel-electric propulsion unit

4 identical permanent-magnet synchro-

nous motors, 2 per shaft, are used to cover

the full speed range. Power is supplied and

speed regulated via inverters. For acousti-

cally optimized operation up to 12 knots,

only 1 motor is required per shaft. The

second motor, typically connected in series,

is separated from the shafting via a clutch.

found that an angular transition design

was preferable in terms of structure weight

and manufacturing costs. Rounding the

angles does not reduce stress levels.

However, it is important that the angles are

supported by the intermediate deck or a

longitudinal wall.

4 Propulsion/drive

Not only the vessel’s shape is new but

also its propulsion concept: the design of

the power generation and propulsion

equipment is similar to that of an all-elec-

tric vessel.

The key components utilize permanent

magnet (PM) technology. These include the

propulsion engines, generators and the

associated power electronics.

4.1 Fundamentals

The higher acoustic requirements and

the travel profile of the FES, which differs

fundamentally from those of a merchant

vessel, have to be taken into account in the

selection and design of the propulsion unit.

Fundamentals for the design of the

propulsion unit with increased acoustic

requirements include:

Research and testing vessel from Thyssen Nordseewerke71


Overview of ship electrical system (Fig. 4)

4 current generating units (2 x 1250 kW

and 2 x 1700 kW) are available for energy

generation. For reasons of modularization,

all 4 generators consist of identical

1700 kW PM generators, which supply the

750 VDC propulsion network via rectifier

cabinets.

The diesel engines are MTU engines

from the 396 series, which meet the emis-

sion limits listed in Annex VI of the

MARPOL Convention (prevention of pollu-

tion from ships). The diesel engines can be

run at light load without limits.

Typically, the port diesel engines power

the port propulsion motors and the star-

board diesel engines the starboard propul-

sion motors. However, cross switching is

possible, as is powering all propulsion

motors from one unit at low speed. In prac-

tical terms, the main switchboard, from

which all 750 VDC consumers are supplied,

represents the DC link between the PM

generators and the PM propulsion motors.

Further major consumers such as the lat-

eral thrust units and the rotating converters

are also supplied with 750 VDC. As electri-

cal power is supplied and removed via con-

trolled rectifiers and/or inverters, normal

network protection via short-circuit power

cutoff is no longer possible. Appropriate

sensors have to be used to determine

in real-time where atypical situations occur

and correct them through suitable

measures.

4.3 Ship electrical system

Since the primary electrical power is pro-

vided as 750 V direct voltage, converters

must produce the 450 V 60 Hz and 400 V

50 Hz. Rotary converters are used to en-

sure high network quality and simple selec-

tive network protection.

All military and civilian voltage systems

are available throughout the vessel via

appropriate transformers, 24 V power sup-

ply units, and distributors. A 400 Hz supply

is also available for special applications.

4.4 Operation and supervision

All facilities related to vessel technology

are designed according to the specificati-

ons of GL (Germanischer Lloyd) for 24-hour

unsupervised operation in the degree of

automation “AUT”. The automation and

control facilities are designed to allow cen-

tral operation and supervision of the

� propulsion facilities,� electrical facilities and� ship operation facilities

from the machine control room and from

the bridge.

In addition to steering the ship and moni-

toring from the control room on the bridge,

the vessel can also be steered from the

bridge wings and from a portable joystick

operator terminal on the aft H-deck. The

entire propulsion facility is monitored by

two controllers, port and starboard. All

equipment needed to steer the vessel is

integrated in these propulsion facility con-

72



Stern view (Fig. 5)

73 Research and testing vessel from Thyssen Nordseewerke


trollers. During dynamic positioning, the

settings are provided by the DP system on

the bridge.

4.5 Special features

In addition to the supply with 750 VDC,

3 AC 450 V 60 Hz, 2/3 AC 115 V 60 Hz

via an IT network and 2/3 AC 400 V 50 Hz

via a TN network as already mentioned, it

is also possible to power the ship from a

containerized fuel cell (“green generator”)

for harbor operation and “silent ship” ope-

ration.

For scientific operation, very high EMC

requirements are placed on the vessel, so

the equipment configuration and cable

routing meets military requirements

to a very large extent (Fig. 4).

5 Scientific equipment and appa-ratus/testing equipment

A wide variety of research equipment

and apparatus is available to the scientists.

There are three laboratories adjoining the

free H-deck, while 4 workshops house a

wide range of tools, from metal cutting

machines to electronic testing devices.

The main crane (maximum 12 tons) and

two auxiliary cranes (2.7 tons), one on the

starboard stern and one on the starboard

B-deck, are provided for lifting loads. In

addition, stern booms, side booms and

further small booms are provided to handle

equipment. For scientific operation, three

winches are supplied. They are installed in

standardized mobile flats to make them

interchangeable. A multibeam echo sound-

er, a sediment sounder, and a surveying

sounder are installed on shipboard sonar

facilities. A Doppler log is also available for

navigation along with a UT (underwater

telephone) facility for underwater commu-

nication. A further sonar, not permanently

installed, is supplied for locating torpe-

does. The control panels and evaluation

equipment for all shipboard sonars are

installed in the central sounding room.

Military towed arrays are used for re-

search and testing, and torpedo search

sonar is used for torpedo testing. The port

hull is provided with a spherical cap which

can be removed to allow the installation of

sonar testing mounts. These projects are

carried out from a separate central testing

room in which the required operating

equipment is also installed for the duration

of the test.

A combined torpedo delivery and ejec-

tion tube is integrated in the vessel to en-

able the testing of various underwater wea-

pons. The first such test will be on the DM2

A4 torpedo, which is currently under devel-

opment.

A conference room is available for meet-

ings. Ten laboratory containers will be sup-

plied with the FES. 5 of these 20” contai-

ners can be placed on the H- and B-decks.

Alternatively, a 40” container can also be

placed on the B-deck. Some of the labora-

tory containers are designed to be coupled

together. The containers allow greater over-

all flexibility for the laboratory equipment.

Naturally, other containerized equipment

and apparatus can also be installed instead

of the laboratory containers (Fig. 5).

The key vessel data are:

Length 73 m

Width 27.2 m

Draft 6.8 m

Displacement 3500 tons

Power 2 x 2,080 kW

Speed 15 knots

Crew 25

Scientists 20

74


The cruise ship Elation with 2 x 14 MW Azipod units (Source: Azipod) (Fig. 1)

Environmentally friendly marine propulsion systemsrely on large-diameter antifriction bearings from Hoesch Rothe Erde

Dr.-Ing. Jörg Rollmann

75


1 Introduction

Large-diameter bearings are extremely

versatile machine components that are

used in different forms in virtually every

segment of mechanical engineering and

transportation. The development of new

technologies is continually expanding the

range of applications. In the past, large-

diameter antifriction bearings have proven

successful especially in general mechanical

engineering systems related to materials

handling and the extraction industries as

well as in harbor, deck and assembly

cranes and earthmoving equipment. Today

such bearings also play an important role

in many new areas of technology. These

include radio telescopes and wind power

systems, tunnel driving machines, offshore

systems and industrial robots (Fig. 2).

Since the 1980s, large-diameter

bearings have also been used in marine

applications as swivel bearings for thruster

systems. Until recently, thrusters have

been used mainly in ships whose operation

calls for high maneuverability, such as

tugboats, ferries and offshore supply

vessels. In these vessels, large-diameter

bearings transmit forces and moments

from the thrust bearings of the ships’

propeller screws, which are driven by a

propulsive power of up to about 6 MW

(Figure 2).

The introduction of innovative, environ-

mentally friendly pod propulsion systems

in shipbuilding is now expanding the range

of applications of large-diameter bearings

to include cruise ships, whose propulsive

power is currently up to about 20 MW.

2 Pod propulsion units

The origin of the pod unit dates back to

a shipbuilding contract for an icebreaker at

the Kvaerner-Masa shipyard (KMY) in

Helsinki in the late 1980s. Built under

contract for the Finnish Maritime Administ-

ration, this ship was to be designed with a

more efficient propulsion system.

Modern icebreakers are generally

powered by diesel-electric propulsion

systems. Diesel engines provide the

primary propulsive power, while generators

convert the kinetic energy into electrical

energy for the electric motors that power

the ship’s propeller screws. The dual

energy conversion in this power train is

more than compensated by the fact that

the diesel engines can operate at their

optimal design level and electric motors are

more economical in the face of inconstant

power requirements. In actual use, ice-

breakers must be highly maneuverable, so

they can break their way out of narrow

channels or exploit cracks opening in the

ice pack.

These requirements are best met by

thrusters that can be rotated about a

vertical axis and thus steer the ship even in

very tight quarters. A weak point of

thrusters, however, is the Z-drive between

the electric motor in the ship and the

propeller screw, which is mounted on a

vertical shaft. This propulsion system, in

Environmentally friendly marine propulsion systems rely on large-diameter antifriction bearingsfrom Hoesch Rothe Erde

Application examples of large-diameter antifrictionbearings (Fig. 2)

76


which the moment must be transferred

through two sets of miter gears, is only

suitable for motors with a power output of

up to 6 MW. Moreover, when thrusting

through heavy ice, the gear sets are also

subjected to severe wear, while the

system’s efficiency is reduced by the

related losses.

To avoid such problems, the engineers

at KMY decided to house the motor and

propeller screw in a pod. The pod is

mounted with 360° rotation beneath the

hull of the ship on a vertical shaft and a

large-diameter bearing (azimuth bearing).

As with a thruster, this design eliminates

the need for a rudder.


decreases mechanical noise. More of the

ship’s interior can be used to make the

passengers’ voyage more comfortable.

Even more space becomes available

because the shaft tunnel is eliminated, as

are the stern thrusters commonly used in

large cruise ships (Fig. 5).

The first cruise ship to be equipped with

pod units in 1997 (2 x 14 MW) was an

engineering upgrade in which only the

electric motors, propeller screws and rud-

der system were replaced by one “Azipod”

each, while the existing power generating

systems were retained. The performance of

this ship could be directly compared with

that of sister ships with conventional

diesel-electric propulsion systems that had

not been upgraded. The upgrade enabled a

40% reduction in turning circle, while the

distance required for a crash-stop was

reduced to 60% of that required by the

sister ship. Moreover, fuel consumption

was decreased by about 8% and vibrations

in the ship were noticeably reduced

(Fig. 1).

In the light of these benefits, newly built

cruise ships are now increasingly designed

for pod systems. By the end of 2001,

16 large cruise ships were equipped with

Azipod systems, including the MS Europa

(2 x 6 MW) and the ships built at the

The pod units did exceedingly well during

the first operations in the icepack. It turned

out that the best way for ships equipped

with a pod system to force their way

through heavy ice is stern first, with the

reinforced propeller screws breaking

through the ice. The stern-first approach

uses only 60% of the power required by

bow-first maneuvers, and higher speeds

are attained. It also became apparent that

the efficiency of the propulsion system was

further enhanced by the use of a pulling

propeller screw, i.e. by a design pointing

the pod in the direction of motion (Fig. 4).

These good results led to the formation of

the ABB Azipod OY company by KMY and

the electrical systems manufacturer ABB

for the continuing development of this

innovative propulsion system under the

name “Azipod”.

Once the “Azipod” system had proven

itself in icebreakers and ice-breaking

tankers, it also attracted the interest of

cruise ship builders. Decisive criteria for

this sector were maneuverability, reduced

fuel consumption, reduced noise, and

better utilization of onboard space.

The reduction in moving masses by

eliminating the long propeller shafts and by

relocating these masses into the pod

outside the ship’s hull substantially

Thruster (Fig. 3)

Icebreaker and flume model with Azipod system (Source: Azipod) (Fig. 4)

77



Meyer shipyard in Papenburg, Germany:

Radiance of the Seas and Brilliance of the

Seas (2 x 19.5 MW each). The success of

the pod systems also brought competitors

into this market, such as the Siemens

Schottel propulsor (SSP) from the Siemens

Schottel consortium. The pod system

developed by SSP uses a permanent

magnet-excited synchronous motor that

requires less space than an electrically

excited motor, so it can be fitted into a

smaller pod with better hydrodynamic

properties. In this design, the power feeds

two propeller screws that are mounted on a

shared shaft at both ends of the pod and

revolve in the same direction, functioning

as a push and pull propeller pair. Several

vessels have already been equipped with

these systems (Fig. 6).

3 Large-diameter bearings forthrusters and Azipod propulsionsystems

As the power output of marine engines

increases, so do the loads that must be

transferred by the large-diameter bearings

that support the pod units or thrusters. A

key task of these large bearings is to

reliably transfer the thrust from the thrust

bearing of the electric motor shaft to the

ship, and to absorb the moment of tilt

resulting from the product of thrust and

shaft length at any given slewing angle. In

specific cases, however, the bearing design

must also take into account the forces and

moments from possible contact of the pod

with the sea floor or with ice.

These tough requirements are met by

three-row roller-bearing slewing rings

mounted between the rotatable pod hous-

ing and the ship’s hull. The three-row roll-

er-bearing slewing ring is a combined

axial-radial roller bearing that withstands

high moments of tilt. The design of these

bearings is illustrated in Fig. 7a. Three bear-

ing rings (A, B, C) enclose two axial rows

and one radial row of rollers. This construc-

tion results in a self-supporting bearing, in

which the loads for each row of rollers can

be clearly defined. All three rings are made

from seamless-rolled, heat-treated steel.

The raceways are case-hardened by an

induction scan hardening process. Through

the use of special spacers a higher number

of rollers is possible, which increases the

load carrying capacity of the roller slewing

ring. The roller-bearing slewing ring is

fastened to the adjacent structure by

through bolts, for which bores are provided

in the bearing rings. The induction hard-

Installation space required for marine propulsion units on cruise ships (Source: SSP) (Fig. 5)


78


ened gear teeth minimize wear in the trans-

fer of the steering moments. Hoesch Rothe

Erde delivers similar bearings as assembly-

ready machine components to all leading

manufacturers of pod propulsion systems.

4 Summary and outlook

The development of pod propulsion

systems increases the efficiency and envi-

ronmental friendliness of ships with diesel-

electric drives. The use of pod systems is

now no longer limited to special-purpose

ships. There are many indications – not only

the increasing demand for environmentally

sound tourism – that these systems are

becoming the standard in large cruise

ships as well. Pod propulsion systems are

already in use in a number of merchant

vessels. Three-row roller-bearing slewing

rings from Hoesch Rothe Erde are an

essential component in this design and

ensure the reliable function of these

propulsion systems.

Cross-section of Siemens Schottel propulsor (Source: SSP) with azimuth bearing* from Hoesch RotheErde (Fig. 6)

a) Three-row roller-bearing slewing ring b) Cross roller bearingLarge-diameter bearing from Hoesch Rothe Erde, examples of azimuth bearings for pod units (Fig. 7)

*


79

Transrapid – innovative rail technology for the world market

The latest Transrapid vehicle, the Transrapid 08, in operation on thetest line in Emsland (Fig. 1)

Dipl.-Ing. Winfried Kracht,

Luitpold Miller,

Dr.-Ing. Friedrich Löser


80 Transrapid – innovative rail technology for the world market

1 The Transrapid project inShanghai

With the first commercial application of

the magnetic levitation train Transrapid in

Shanghai, this mode of transportation has

again become the focus of public attention.

In Shanghai, ThyssenKrupp and its

consortium partners Siemens and the joint

venture Transrapid International are linking

the large new Pudong International Airport

to the downtown subway network with a

line that is roughly 30 km long and extends

to the Longyang Road subway station.

As recently as the summer of 2000, a

feasibility study was begun together with

the Chinese side. In January 2001, the

contract was signed – and on January 1,

2003, the Chinese President Zhu Rongji

will take a first ride. Commercial service is

expected to begin a year later. A German

consortium of technology companies is

delivering the required trains, the energy

supply, the propulsion system, the

guidance technology and the guideway

equipment required by the propulsion

system. The Chinese side is building the

guideway according to the design

instructions of a German consortium made

up of construction companies and

consultants.

The technology being used in China is a

German development, in particular by

Thyssen, which decided to invest in the

Transrapid technology in the late ’70s. In

the early ’80s, the German government

gave considerable support to the

construction of the test facility in Emsland

on which, following the TR 06 and TR 07

prototype vehicles, the 8th-generation

vehicle (TR 08) is now running (Fig. 2). This

vehicle was built in the Thyssen Transrapid

center in Kassel.

2 The Transrapid principle

The Transrapid system was designed for

passenger transport at speeds of up to 500

km/hour in fully automatic operation. It is

the first fundamental innovation in rail

technology since the construction of the

first railroad – the first train system that

moves without axles and wheels. Electronic

components immune to wear take the

place of mechanical parts.

The heart of the Transrapid technology is

a non-contacting electromagnetic

levitation, guidance and propulsion system

that takes over the functions of the wheels

and rails (Fig. 3). The propulsion magnets

draw the vehicle to the guideway from

below; guidance magnets keep it centered

on the track laterally. An electronic control

system ensures that the train levitates

approximately 10 mm above its guideway.

In contrast to a car or railroad, the motor

of the high-speed magnetic train is located

not in the vehicle itself but in the guideway.

The operation of the long-stator linear

motor can be compared to that of a

rotating electric motor whose stator is cut

open and stretched. Instead of a rotary

magnetic field, it produces a traveling field

which propels the train synchronously and

without contact via its support magnets. If

the direction of the traveling field is

changed, the motor becomes a generator

that brakes the vehicle without any contact.

Compared with the wheel-rail train under

similar conditions, the Transrapid system is

quieter, smoother, consumes less energy

(Fig. 4) and requires lower investment and

operating costs. Also, the advantages of

the system allow considerably higher

speeds at comparable rates of energy

consumption. At the same time, because

of its high flexibility, the guideway can be

integrated into the landscape as most

appropriate – elevated, near the ground or

at grade, even in densely populated urban

areas – all the while allowing for high

traveling speeds. Combining these

properties opens up applications not only

as a means of high-speed, long-distance

transportation but for airport shuttles, such

The evolution of the Transrapid 08, which will now be used in Shanghai (Fig. 2)

HMB2 (1976)

TR05 (1979)

TR06 (1984)

TR07 (1989)

TR08 (1999)

➡

➡

➡ ➡



as in Shanghai, or for regional transport.

Feasibility studies are currently being

carried out in Germany for an airport

shuttle application in Munich and for a

regional “Metrorapid” linking Dortmund

and Düsseldorf in the Rhine-Ruhr area.

Additional application studies are underway

in the USA for a Pittsburgh airport link and

a line connecting Baltimore and

Washington. And studies are being done in

the Netherlands as part of the “Rondje-

Randstad Project” (Amsterdam – Utrecht –

Rotterdam – The Hague – Amsterdam),

and for a line from Amsterdam to Bremen

via Groningen and on to Hamburg.

Additional applications will emerge not only

because of the high level of availability and

security, but also due to the attractiveness

from the user’s point of view.

3 The vehicle

The vehicle wraps around the guideway

and is therefore prevented from derailing

(Fig. 5). Depending on the application,

a train can be made up of 2 to 10 sections,

each roughly 25 m long, and can

transport around 100 passengers in each

section.

In order to achieve a high level of

comfort even during rides through tunnels,

the vehicle body is pressure sealed for a

load of 6,000 Pa. To satisfy this

requirement while maintaining low weight,

a hybrid solution consisting of hollow

aluminum sections and aluminum

sandwich panels was chosen.

The cylindrical part of the body is

composed of three sandwich section

modules, the complete roof and the left

and right floor/sidewall units. These three

main modules account for the full length of

approximately 24 m of the cylindrical part

of the body. The sandwich components for

the passenger compartment and the

exterior chassis fairing consist of aluminum

paneling and a core of rigid foam. The

bonding is done with epoxy resin. The

components have a wraparound aluminum

section that is connected to the aluminum

paneling by means of laser welding. This

results in:

� better protection of the core material

and the bond� high load capacity through continual

introduction of the load into the sandwich

assembly� a simple technique for bonding the

wraparound aluminum sections with the

longitudinal extruded aluminum sections

of the vehicle structure by means of

riveted joints

Locomotive state of the art: Wheel-on-track systems have been replaced by electromechanical levitation (Fig. 3)

Comparison of energy consumption (Fig. 4)

Wheel-on-rail Electromagnetic levitation

GuidanceGuidance

Propulsion

Propulsion

SupportSupport



The spherical nose sections of the body

consist of self-supporting glass-fiber

reinforced sandwich components with

carbon and glass-fiber reinforced polyester

resin paneling. To conform to lightning

protection requirements, a copper netting

(weight 80 g/m2) is laminated into the

whole surface of the glass-fiber reinforced

structure. To achieve adequate penetration

resistance – the sandwich structure must

withstand the impact of a 1 kg standard

brick moving at 600 km/h – a rubber-

aramide layer is integrated into the

sandwich structure. The sandwich

components in the front are manufactured

using the vacuum injection process and

bonded with the cylindrical body structure

using polyurethane cement.

Each levitation chassis consists of two

levitation frame units that wrap around the

guideway and a longitudinal connector, all

of which are bolted together. Redundant

screw joints are arranged in the power

flux. Because of the low strain they

experience when the vehicle moves, the

structural components can be manufac-

tured inexpensively from extruded alumi-

num sections and aluminum sand castings.

In the case of the levitation frame in the

nose area, a supporting structure made of

extruded aluminum sections is mounted at

the front of the levitation frame unit to

accommodate five collision elements and

to fasten the frame-mounted nose paneling.

The collision elements are arranged

across the width of the guideway. The

deformation elements and the vehicle

structure are designed in such a way that

operational safety is ensured should the

following events occur:

� Collision with a 15 kg object on the

guideway while the train is moving at

500 km/h� Collision of the nose section with a 50 kg

object lying in the middle of the

guideway while the train is moving at a

speed of 500 km/h� Collision of the nose section with a tree

trunk lying on the elevated guideway at

an angle of 45° while the train is moving

at 500 km/h

� Collision of the nose section with a tree

trunk lying across the guideway while the

train is moving at 500 km/h

The box structure accommodates the

modules for the power supply, magnet

control, guidance electronics and

pneumatic system, which are installed as

slide-in units, as well as the equipment for

air conditioning, suspension and the

control of the onboard power supply. The

EMC-shielded cable ducts that separately

house the halogen-free power and

signaling cables are an integral part of the

structure. On the guideway side, the box

structure has a floor with a flat surface. The

chassis supports — two aluminum

sections each mounted on the outsides of

the box structure — guide the compressed

air in three channels for the activation of

pneumatic springs, doors and current

collectors.

The box structure essentially consists of

a riveted aluminum structure with

longitudinal extrusion sections and

bulkheads arranged lengthwise and

crosswise. The bulkheads consist of

aluminum sheets 3 to 4 mm thick. They are

riveted to the floor and the extrusion

sections. The floor is made from

longitudinally welded aluminum extrusion

sections.

4 The guideway equipment

The guideway equipment forms the

interface between the vehicle and the

guideway for the suspension, guidance,

propulsion and braking functions. The

components transmit the forces between

the vehicle and the guideway and

constitute a part of the magnetic control

system for realizing non-contacting

The guideway and vehicle system with the most important system components. The vehicle wraps aroundthe guideway and therefore cannot derail (Fig. 5)

Electromagnetic levitation

Stator pack

Guidance magnetEddy current brake

Guidance rail

Supportmagnetlineargenerator


Long-stator winding: Guideway equipment and vehicle magnet module (Fig. 7)(Source: GP Dr. Grossert Planungsgesellschaft)


magnetic suspension and guidance. The

guideway equipment includes

� Stator packs� Long-stator windings� Location reference flags

The stator packs are about 1 m long and

0.18 m wide and weigh roughly 100 kg.

Each stator pack consists of 360 magnetic

steel laminations with a thickness of

0.5 mm and 3 slotted crossmembers for

fastening it to the guideway support. The

stator packs are cast in epoxy resin in a

vacuum and in this way permanently

protected from the effects of weather. The

slots of the stator packs are shaped in such

a way that the long-stator winding can

be secured positively in the slot in an auto-

matic laying process. The system dimen-

sion for the stator packs is 1,032 mm. This

corresponds to twice the cycle length of the

traveling magnetic field, which is 516 mm.

To take account of the assembly

requirements, balance out lengths in

curves and make provision for expansion

joints on the guideway girder joints, three

types of stator packs are being used. They

have varying lengths that are less than

the system dimension (1,030 mm;

1,027.5 mm; 939 mm). For the Shanghai

project alone, 126,000 stator packs are

required.

In order to locate the trains using the

operation control technology, absolute

position information is fixed on the

guideway at intervals of 200 to 1,000 m in

the form of passive, digitally encoded flags.

The absolute position information is read in

redundantly by the vehicles. At every

absolute position, three location reference

flags with a total of 12 bits of location

information are set up redundantly on both

sides of the guideway (Figs 6 and 7).

These location reference flags consist of a

holder that is fastened to the guideway

support in the area of the long stator and a

plastic body. The plastic body contains the

location information in the form of a

copper-laminated circuit board cast in

epoxy resin.

The long-stator winding is realized as a

three-phase traveling field winding. Every

winding strand is created by means of

meandering and bending of the traveling

field wire (Fig. 8). The conductors consist

of aluminum wires with a total cross

Stator pack profile

Fixing LRF

Long stator winding

Guidance rail

Stator pack

Lacation reference flag (LRF)

Phase 1 (u)Phase 2 (v)Phase 3 (w)

Fixing LRF

Location reference flag (LRF)

Levitation frame

Guidance magnet

Guidance rail

Stator pack profile

Stator pack

Long stator winding

Levitation magnet

Long-stator winding: Equipment module with guideway components (Fig. 6)(Source: GP Dr. Grossert Planungsgesellschaft)


Transrapid – innovative rail technology for the world market84

sectional area of 300 mm2. The high-

voltage insulation consists of ethylene-

propylene rubber for a maximum operating

voltage of 20 kV. The copper sheath and

the conductive outer shell consist of

chloroprene rubber.

To create defined grounding conditions

on the outer shell of the traveling field

winding, the stator packs are faced with

stainless steel laminations, which are

interconnected by means of a grounding

cable. At the ends of the guideway

supports, the grounding line is connected

to the grounded guideway structure.

The long-stator winding is created with

a mobile laying unit on the guideway

supports. The traveling field wire is

unspooled from the transport drum, put

into the meandering shape of the traveling

field winding with a bending device and

pressed into the slots of the stator packs.

The process is carried out for each of the

three winding strands in succession. This

method of laying the windings was tested

with manually controlled prototype devices

and developed further for automatic

operation.

5 Switches

The switches are another primary

element of the overall Transrapid system

for which ThyssenKrupp is responsible.

They are made of welded steel in lengths

between 70 and 300 m. On straight line

sections they can be crossed at a speed of

500 km/h, on bends at up to 400 km/h,

depending on the switch length. The

switches are shifted and locked

electrically.

6 Development potential andprospects

The Transrapid technology has a great

deal of potential for innovation, especially

with regard to the electronic modules of the

suspension and guidance system. Here,

developments in microelectronics will help

further reduce weight and volume and

lower the costs. The same applies to the

electric components of the suspension and

guidance magnets, where advances in

insulation technology and manufacturing

processes also make additional

improvements possible, particularly when it

comes to volume production.

The coming decades will bring increased

demand for transportation services

worldwide. At the same time, ever greater

importance will be attached to accessibility,

safety, environmental impact and the

economical use of resources. The

Transrapid vehicle technology provides an

attractive solution to these requirements.

Device for bending the traveling field wire (Fig. 8)

85


Certified pre-owned CNC machines:The alternative to new equipment

Bremen Technology Center of Hogema Gebrauchtmaschinen GmbH (Fig. 1)

Wolfgang Schmidt

86


Certified pre-owned CNC machines: The alternative to new equipment

1 Introduction

Global demand for machine tools is

running high. This is borne out by statistics

recently published at the EMO trade show

that confirmed peak volumes in machine

tool imports as well as exports. A ten-

percent increase over the prior year to

€10 billion – a new record – is projected

for Germany’s machine tool production

in 2001.

But investments in new equipment are

not necessarily the best choice for every

production site. Nor does a high degree of

automation guarantee success in every

country. An extremely dynamic trade in

used machines is therefore thriving along-

side the market for new equipment. Its

growth rate of around 18% even exceeds

that of new machines. The export share of

used machines exceeds 50%. Demand has

recently soared not only in countries like

Canada, the People’s Republic of China,

Spain, the Czech Republic and in parts of

Asia but also in the USA and in neighboring

European countries.

Trading in used machine tools therefore

offers significant opportunities that can be

further increased by using more profess-

ional methods, because in this respect –

broadly speaking – there is still a lot of

room for improvement. Against this back-

ground, Hogema Maschinenhandel GmbH

was established in 1990. Hogema

Gebrauchtmaschinen GmbH is a subsidiary

of the Hommel Unverzagt group, a manu-

facturer-independent sales and customer

service organization for CNC machine tools

within the ThyssenKrupp Serv segment.

Hogema Gebrauchtmaschinen GmbH pro-

vides a broad spectrum of services and

support focused on the purchase and sale

of pre-owned machine tools for metal

cutting applications. With three locations in

the German cities of Cologne, Bremen and

Schramberg, Hogema is a highly compet-

ent supplier of CNC lathes, machining

centers, grinders and honing machines for

German and international customers.

2 The concept

The core competency of the Hommel

Unverzagt group is the exclusive sale in

Germany, Austria and Slovenia of new CNC

machine tools from various manufacturers,

including a comprehensive spectrum of

financing and other services and support.

But every new machine will eventually

become a used machine. Neglect of these

machines might degrade their performance

and thereby mar the brand image – even

the reputation of the company’s new

equipment. This was one of the reasons

why the Hommel Unverzagt group decided

to become active in this market by estab-

lishing Hogema Gebrauchtmaschinen

GmbH. The central idea is to integrate the

sales force while closely tracking the

machine-tool market as a whole.

The process of accepting machines as

trade-in, certifying and reintroducing them

into the cycle creates the opportunity of

influencing their entire life cycle. What sets

Hogema apart from other manufacturer-

independent machine-tool dealers when it

comes to implementing this process with a

high degree of professionalism is the

access it has to the competencies of its

sister companies. With this wealth of know-

how, business connections and com-

prehensive services, Hogema can achieve

a high level of professional excellence that

puts the company out in front in the

pre-owned machines business.

This cooperation among the sister

companies also benefits the financial

services company Hommel CNQuickFinanz,

the services company ComLink Service

and the sales companies Hommel CNC-

Technik, UVA Unverzagt, Hommel Präzision

Process flow plan of Hogema CNC-Gebrauchtmaschinen International (Fig. 2)

87



and precisa CNC Werkzeugmaschinen.

Trade-in acquisitions of ThyssenKrupp

machines or third-party equipment, which

are often the key to new-equipment sales,

are handled reliably by the pre-owned

equipment company. What’s more, the

company’s expert knowledge of the market

and machines in the pre-owned machines

sector allows precise calculations of

residual values, and this in turn translates

into favorable financing terms and rates.

Another advantage is more incidental: In

special cases, for instance when deliveries

are delayed or when orders are at a peak,

Hogema’s machine rental service helps

customers bridge the gap.

Customers are the ultimate beneficiaries

of these mutual and synergistic effects.

After all, these interlinked resources enable

the Hommel Unverzagt Group to live up to

its claim of providing a full spectrum of

services focused on profitable machining.

3 Hogema’s productsand services

Hogema’s range of machines encom-

passes CNC lathes, milling machines/

machining centers, grinders and honing or

cross-grinding machines from all of the

manufacturers sold by the Hommel

Unverzagt Group as well as by other

manufacturers. The majority of the mach-

ines originate in the product programs of

the sister companies: Okuma, Okuma-

Howa, Nakamura-Tome, Hwacheon, Fadal,

Colchester, Okamoto, Kellenberger and

Sunnen. In many cases the machines are

obtained from expiring financing agree-

ments or as trade-ins and are no more

than ten years old. Every machine is sold in

top condition and with a test certificate.

Hogema handles the acquisition and

sale on behalf of customers or on the

company’s own initiative as well as the

evaluation, corrective maintenance,

reconditioning and brokering of machines

from various manufacturers. Hogema

furthermore provides its customers with the

same range of services available to the

new equipment customers of the Hommel

Unverzagt Group.

This includes:

� Pre-sales services: technical and com-

mercial consulting, financial consulting,

time/profitability studies, accessories,

customized leasing and financing

models, machine insurance. � Training and know-how transfer:

introduction to operation/programming of

the machines, CNC/CAD/CAM training,

individual, one-on-one training.� After-sales services: transportation,

installation, commissioning, ServiceLine,

troubleshooting, customized inspection

and maintenance agreements, spare

parts management, customized add-on

warranties.

The motto for used machines offered

by Hogema is like that for the new machine

business within the Hommel group: The

customer gets whatever services the custo-

mer wants. That these services come at a

price goes without saying.

Backup by the Hommel Unverzagt Group: Modular range of services equivalent to the new machine market(Fig. 3)

USP customer service: Highly efficient hotlinesupport minimizes downtimes (Fig. 4)

88



3.1 USP financial services

To ensure the liquidity of the customers

independently of banks, Hogema offers its

customers flexible purchasing and insur-

ance models in exclusive cooperation with

its sister company CNCQuickFinanz and the

latter’s partner Deutsche Leasing AG.

The advantages of leasing are obvious:

No large tie-up of capital, no impact on the

balance sheet, reduced taxes. In a financ-

ed purchase the “pre-owned” equipment

becomes the user’s property and can be

fully depreciated. The customer acquires

an asset while also protecting its own

liquidity. Leasing and financed purchase

are available in four basic versions, so the

financing model can be attuned to the

individual needs of the company.

Hogema’s pre-owned equipment

customers also have access to insurance

services providing coverage against fire,

downtime or a machine crash.

3.2 USP customer supportservices

Customer support services for Hogema’s

pre-owned machines are also the same

as for the company’s new machines. These

services are provided in collaboration with

Hogema’s own technical staff, third-

party service providers and ComLink

Service GmbH, a sister company. Services

can be modularly combined and include

components such as installation, com-

missioning and training of the operating

personnel as well as programming courses

for the user.

The customer moreover has access to

extensive after-sales service by ComLink

Service. In addition to conventional

services such as inspection, maintenance

and repair ComLink also provides special

billable services. These include machine-

specific maintenance agreements, each of

which is accompanied by a machine-

specific uptime guarantee of up to 98%

according to the VDI 3423 guideline

(VDI = German Engineers’ Association).

Another way of minimizing costly

machine downtime is ServiceLine (a high-

quality telephone support service available

in two versions, Basic and Premium).

Unlike many hotlines, ServiceLine is

reliably available ten hours daily. Its

highly qualified experts restore machine

function over the telephone in verifiably

over 60% of all cases.

Even beyond Germany’s borders

Hogema has the structures in place to

support used machines throughout their

life cycle. In Austria and Slovenia the

required services are provided by precisa

CNC Werkzeugmaschinen GmbH a sister

company. In other countries Hogema works

with selected service partners.

4 The process

4.1 Acquisition/procurement

The 12-member Hogema team does not

wait passively for trade-ins to flow in from

its fellow sales companies. Instead the

trading company takes the initiative

pursuing good pre-owned CNC machines

in the marketplace. The team uses

every available tool and a diversity of

approaches. Trade-in acquisitions are

actively pursued with Hommel Unverzagt

customers; alternatively these customers

may approach Hogema when requirements

arise. Since customers’ machine tools are

registered with a complete history in the

customer service database of Hommel

Unverzagt, an especially accurate machine

evaluation is assured. Market prices are

generally paid.

Hogema furthermore uses advertise-

ments or the internet to extend its search

activities into international markets.

Participation in international trade shows (Fig. 5)

89


Rapid on-site service by experienced field servicetechnicians (Fig. 6)

Potential wear parts are replaced by high-qualityOEM parts (Fig. 7)


Searches are conducted either on Hoge-

ma’s own initiative or against customer

orders. Here the motto is: Virtually any kind

of CNC or conventional machine can be

obtained on customer request. The

company can live up to this due to its

excellent international customer contacts.

As a rule the machine is acquired by

Hogema. In a minority of cases Hogema

only acts as an intermediary.

4.2 Technical procedures andquality assurance

Every incoming pre-owned machine is

first thoroughly cleaned before being tested

by a Hogema engineer. This thorough

checkup is conducted systematically

according to a comprehensive protocol.

A Renishaw measurement system is used

in testing machining centers. In what is

known as Q 10 testing, nearly all para-

meters are measured and displayed on the

computer both graphically and numerically.

The evaluation of lathes for instance

includes criteria such as the external con-

dition of the machine, operating panel,

scraper and slideways of the different axes,

running noises in the drives, spindle or

sub-spindle, functioning of the turret index-

ing, fan, chuck and clamping cylinder,

tailstock, the entire lubrication system,

coolant system, chip conveyor and many

other points. Measuring the geometry and

operating times of the various components

is also part of the general check-up. The

protocol is used to determine appropriate

measures based on application-related,

technical and economic considerations. As

a rule these decisions concern the replace-

ment of potential wear parts by OEM new

parts.

Virtually all of the technical inspections

and tests of machines are conducted by

the company’s own technical experts in the

Bremen technology center and at WIG in

Cologne, an industrial maintenance

company within ThyssenKrupp Serv.

Uncommon and particularly complex tasks

such as surface-grinding a bedway are

performed by specialized partner compa-

nies. An intensive test run is followed by a

comprehensive machine acceptance test,

complete with a test log (certificate).

Machines are always categorized according

to the quality classes defined by the FDM

(German industry association for the

machine and tool wholesale trade). The

rock-solid documentation of the individual

pre-owned machines is a boon to custo-

mers as it provides transparency about the

machine and assures its reliability as a

production tool.

Customers can personally check out the

consistently excellent condition of Hogema

pre-owned machines at the company’s

technology centers in Cologne, Bremen

and Schramberg. Just like in new machine

sales, competent professionals are

available there for consulting – also

regarding issues relating to financing and

service. These experts are pleased to give

practical workpiece-specific demonstra-

tions on request.

4.3 Sales structure

Nearly half of all Hogema machines find

new owners not far away within Germany –

often customers of the Hommel Unverzagt

Group. That is not surprising, since about

20,000 active machines at over 6,000

customer organizations represent a

dynamic market. Especially in combination

with the dependable support services by

Hogema, these pre-owned machines in

their certified top condition provide comp-

anies with additional capabilities and the

flexibility to respond swiftly to changing

production requirements.

But well over 50% of the used machines

travel far afield. Demand has recently

soared especially in Canada, China, Spain,

the Czech Republic and parts of Asia.

Machines are also being exported to the

USA and to neighboring European

countries. In this business, international

90



electronic marketplaces that provide inter-

active virtual exchanges are commercial

hubs the Hogema team uses successfully.

Foremost among these marketplaces

is the company’s own website at

www.hogema.de. Up to 30 inquiries are

received here daily. Its clear layout and

intelligent search engines enable visitors to

rapidly review the entire list of available

machines or to apply search criteria that

will pinpoint the particular machine they

want. A typical line-up of 50 machines at

any given time provides a very good

chance of finding the right equipment.

About 100 machines change hands

through this efficient hub every year.

The Hogema team also works with other

internet exchanges. A particularly

successful cooperation has developed with

www.okuma-used.com, an affiliated,

single-brand exchange managed by

Hommel Unverzagt that benefits from a

convenient layout similar to Hogema’s own

online marketplace. Another site that is

proving increasingly useful is www.machi-

neStock.com. This is the new portal of the

pre-owned machine working group of the

FDM, which pursues no commercial

interests of its own and has about 300

members. The more than 5,000

immediately available machines from

different manufacturers are listed on this

dealer-owned platform.

5 Customer value

The lower investment for pre-owned

machine tools can certainly enhance the

financial flexibility of companies. But in

many case this is offset by considerations

concerning quality, trouble-free

commissioning, performance in actual use,

uptime reliability, warranty and support

services including concerns about long-

term availability of spare parts.

It is precisely these – entirely rational –

reservations of cautious decision-makers

which Hogema is dispelling by its highly

professional approach. Trustworthy

inspections with certification, live demos

and work trials, a large stock of spares and

replacement parts and a network of comp-

etent technicians provide customers in the

pre-owned machine market with an

exceptional degree of assurance. Added to

these are the financial advantages related

to the comprehensive financing and

support services, which are equivalent to

those offered alongside new machine sales

and provide Hogema with a unique selling

proposition.

In addition to a high degree of well-

justified confidence, Hogema customers

also enjoy a maximum in flexibility as a

result of the modest tie-up of capital and

prompt availability. All good reasons why

Hogema has detected a definite increase in

the acceptance of pre-owned machines –

even among large companies that have

traditionally invested exclusively in new

equipment.

International hub for pre-owned machines: Hogema’s easily navigable website (Fig. 8)


forum – Technische Mitteilungen ThyssenKruppContent Volume 3 / 2001

Issue/Page

Algenstaedt, C. E-commerce as a success factor in future materials marketing at Thyssen Schulte 1/67

Bartels, R. J. Manufacturing flexibility in powertrain production 2/26

Bastin, A. E-business solution for the transport industry: Telematics-based fleet management using the internet and online planning 1/73

Batres, U. CENDI – an organization created to promote the development of the stainless steel market in Mexico 1/27

Baumann, A. Organized decentralized purchasing via the internet at Krupp Presta 1/46

Berger, M. see Bartels, R. J.

Birkert, A. Hydroforming Knowledge Store 1/41

Bork, M. New applications of high-pressure extraction 2/31

Braun, M. Research and testing vessel from Thyssen Nordseewerke 2/68

Brewka, Chr. Krupp Canada supplies the world’s largest downhill conveyor system 2/49

Brill, U. WDISweb: Searching for the optimum material on the internet 1/31

Bussmann, B. SVI Noord-Brabant sewage sludge incineration plant, Netherlands 2/56

Cebulla, A. see Bastin, A.

Deimel, Th. Service product “impact performance” – hydraulic hammer with integrated electronic evaluation unit for remote transmission of performance data 1/62

Dejaco, S. The new modular steering column from Krupp Presta 1/51

Dierkes, H. see Bork, M.

Dorighi, D. Online Sales at ThyssenKrupp Stahl 1/09

Euler-Schreiter, D. Innovative elevators and escalators for a safe future 2/13

Giger, H. see Baumann, A.

Halbleib, A. Developing the future in cement manufacturing technology 2/41

Hebel, A.-Th. E-purchasing at ThyssenKrupp Stahl via the internet-based “W3AS” online RFQ system 1/13

Hedding, K. E-Business@Hoesch Hohenlimburg 1/21

Henßen, G. Membrane electrolysis – innovation for the chlor-alkali industry 2/36

Hernandez, C. see Batres, U.

Hollung, A. see Braun, M.

Humberg, H. see Brill, U.

Jacke, R. E-procurement at ThyssenKrupp Stahl by means of electronic catalogues on the intranet and internet 1/17

Jungemann, L. B2B in industrial plant construction - spare parts distribution for cement works 1/58

Körner, J.-P. see Bork, M.

Kracht, W. Transrapid – innovative rail technology for the world market 2/79

TK


Issue/Page

Kripzak, B. see Jungemann, L.

Laukas, P. see Baumann, A.

Lemm, K. see Jungemann, L.

Leonhardt, S. see Birkert, A.

Löser, F. see Kracht, W.

Ludescher, E. see Baumann, A.

Maas, U. see Halbleib, A.

Magallón, J. R. ThyssenKrupp Airport Systems passenger boarding bridges at Düsseldorf International Airport 2/18

Mehl, R. The “Sachsen” – impressions from the sea trials 2/63

Miller, L. see Kracht, W.

Müller-Beckhoff, R. see Jacke, R. und Hebel, A.-Th.

Nünnerich, P. see Bork, M.

Orthmann, K. Bilstein shock absorbers via www.Bilstein.de 1/36

Prokop, H.-J. see Deimel, Th.

Rollmann, J. Environmentally friendly marine propulsion systems rely on large-diameter antifriction bearings from Hoesch Rothe Erde 2/74

Sainz, A. see Magallón, J. R.

Schilling, J. see Bussmann, B.

Schmidt, W. Certified pre-owned CNC machines: The alternative to new equipment 2/85

Schneiders, K. see Henßen, G.

Scholley, H.-F. von The EVOLUTION® traffic elevator for railroad station platforms from Thyssen Aufzugswerke 2/09

Schulz, J. SerKom – the mobile communication solution for service engineers 1/54

Shehata, M. see Brewka, Chr.

Solèr, I. see Baumann, A.

Steinhagen, V. see Bork, M.

Sünkel, R. see Birkert, A.

Thelen, D. see Baumann, A.

Truetsch, K. see Birkert, A.

Wippermann, St. see Dorighi, D.

Worpenberg, F. “DUAL” and LOWRIDER”, two new passenger boarding bridges for small and medium passenger aircraft 2/22

Zimmermann, A. see Henßen, G.

Zurhove, F.-J. see Halbleib, A.

forum – Technische Mitteilungen ThyssenKrupp, Content Volume 3 / 2001 - continued

forum thyssen krupp

Documents

general engineering

plant engineering

mining equipment

specialpurpose machinesas

transportation of people

steel cages

naval shipbuilding

andcapital goods