blt process manual

8/17/2019 Blt Process Manual

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Functional Design Specifications ZC-14200-FDS 100804 Rev F.doc2/104

CONFIDENTIALINFORMATIONSEE PAGE 3

GENERAL DOCUMENT INFORMATION

ISSUE TO CUSTOMER: Yes

REVISIONS

REVISION REVISION WRITTEN VERIFIED APPR. REVISED COMMENTSN° DATE BY BY BY PAGES

A Nov 9, 09 WKN LNY First issue for reviewB Nov 19, 09 YKN LNYC Nov 24, 09 YKN LNY 27,88,101,

107

D Jan 6, 10 YKN JLR 56

21, 23

Dual pressure sensorsfor MHO addedDiagrams modified

E Aug. 2, 10 WKN JLR Local stationsF Aug. 4, 10 WKN JLR Local HMI functions

changed to PBs





IMPORT NT NOTICE

CONFIDENTIAL INFORMATION

THE INFORMATION SET FORTH HEREIN CONSTITUTES PROPRIETARYTECHNOLOGY OF PAUL WURTH S.A.

THE RECIPIENT OF THIS DOCUMENT AGREES

NOT TO COPY OR REPRODUCE SAID DOCUMENTS IN WHOLE OR INPART WITHOUT WRITTEN APPROVAL FROM PAUL WURTH S.A.

NOT TO DISCLOSE SAID DOCUMENTS TO ANY THIRD PARTY WITHOUTWRITTEN APPROVAL FROM PAUL WURTH S.A.

TO MAKE NO USE OF SAID INFORMATION OTHER THAN FOR THE

PURPOSE OF ENGINEERING FOR Rourkela BF5.





T BLE OF CONTENTS

1 G ENERAL DESCRIPTION .....................................................................................8

1.1 Reference Documents.................................................................................. 81.2 System Overview ......................................................................................... 91.3 Bell Less Top® Charging System Description ............................................ 10

1.3.1 Charging Capacity.................................................................................................101.3.2 Performance Criteria ............................................................................................. 101.3.3 Mechanical Equipment of Bell Less Top ................................................................ 111.3.4 Bleeder Valves...................................................................................................... 13

1.4 Process Sequence..................................................................................... 13

1.5 Auxiliary Systems of the Bell less Top........................................................ 141.5.1 Hydraulic System Overview................................................................................... 141.5.2 Water Cooling System Overview ........................................................................... 141.5.3 Gearbox Nitrogen and Purging .............................................................................. 151.5.4 Steam Heating ...................................................................................................... 151.5.5 Greasing ............................................................................................................... 15

1.6 Nomenclature............................................................................................. 16

2 AUTOMATION AND CONTROL S YSTEM H ARDWARE .............................................18

2.1 Control philosophy...................................................................................... 182.1.1 Local control.......................................................................................................... 182.1.2 Failure analysis ..................................................................................................... 192.1.3 Relationship to Stockhouse ................................................................................... 192.1.4 Diagnostics and data logging.................................................................................19

2.2 System Architecture ................................................................................... 202.2.1 Redundancies .......................................................................................................202.2.2 Control System Diagram ....................................................................................... 212.2.3 Controller Components.......................................................................................... 212.2.4 HMI Interface ........................................................................................................ 212.2.5 Interfaces to Other Systems .................................................................................. 22

2.3 Panel Block Diagram.................................................................................. 23

2.3.1 Voltage levels........................................................................................................ 232.3.2 Wiring Standards................................................................................................... 242.3.3 Controller panel..................................................................................................... 242.3.4 Main I/O Panel ...................................................................................................... 242.3.5 Motor Power Panel MCC....................................................................................... 252.3.6 MCC I/O panel ...................................................................................................... 252.3.7 Drives ................................................................................................................... 262.3.8 Operator control stations ....................................................................................... 30

2.4 Emergency Stops....................................................................................... 33

3 BLT F UNCTIONAL DESCRIPTION ......................................................................34





3.1 BLT Modes of Operation ............................................................................ 343.1.1 Automatic Mode .................................................................................................... 343.1.2 BLT Semi-automatic Mode .................................................................................... 343.1.3 Manual Mode ........................................................................................................ 353.1.4 Local Mode ........................................................................................................... 35

3.2 Charging Methods ...................................................................................... 363.2.1 Spiral Charging ..................................................................................................... 363.2.2 Ring Charging ....................................................................................................... 363.2.3 Sector Charging .................................................................................................... 373.2.4 Point Charging ...................................................................................................... 37

3.3 Chute Angle / Ring Transition Methods ...................................................... 373.3.1 Time based ring pattern......................................................................................... 373.3.2 Weight based ring pattern...................................................................................... 37

3.4 Charging Program (Matrix) ......................................................................... 383.4.1 Charging Matrix Fields...........................................................................................383.4.2 Portion Based Charging Matrix .............................................................................. 393.4.3 Percentage Base Charging....................................................................................39

3.5 Charging Modes......................................................................................... 403.5.1 Auto Start Charging...............................................................................................403.5.2 Inhibit Furnace Top Filling ..................................................................................... 413.5.3 Inhibit Discharge ................................................................................................... 423.5.4 Stop Charging ....................................................................................................... 42

3.6 BLT Sequences.......................................................................................... 423.6.1 Preferred Hopper and Catch-up Mode ................................................................... 433.6.2 Relieve to Atmosphere .......................................................................................... 433.6.3 Prepare for Material............................................................................................... 44

3.6.4 Fill Hopper.............................................................................................................443.6.5 Equalize (Pressurize Hopper) ................................................................................ 453.6.6 Discharge Hopper .................................................................................................463.6.7 Chute Tilt and Material Flow Gate during Discharge .............................................. 47

3.7 Detailed Device Operation and Interlocks................................................... 483.7.1 Distribution rocker ................................................................................................. 483.7.2 Upper seal valve ................................................................................................... 493.7.3 Lower seal valve ................................................................................................... 503.7.4 Relief valve ........................................................................................................... 503.7.5 Primary equalizing valve........................................................................................ 513.7.6 Secondary equalizing valves ................................................................................. 513.7.7 Material flow gate.................................................................................................. 523.7.8 Chute Tilting Drive................................................................................................. 533.7.9 Chute Rotation Drive ............................................................................................. 543.7.10 Goggle valve........................................................................................................ 55

3.8 Control Loops............................................................................................. 553.8.1 Sonic Flow detectors .............................................................................................553.8.2 Weighing Equipment ............................................................................................. 563.8.3 Material Flow Gate Algorithm................................................................................. 603.8.4 Centre coke charging ............................................................................................ 61

3.9 BLT HMI Screens....................................................................................... 62

3.9.1 Bell-less Top Overview.......................................................................................... 62





3.9.2 Bell-less Top Detail Screen ...................................................................................633.9.3 Charging Matrix Screens .......................................................................................683.9.4 Chute Angle Screen .............................................................................................. 693.9.5 Device Faceplates (pop-ups)................................................................................. 703.9.6 Trend Screens....................................................................................................... 71

4 P LANT INTERFACES .........................................................................................73

4.1 Stockhouse Interface.................................................................................. 734.1.1 Data Locations ...................................................................................................... 734.1.2 Data Exchange Requirements............................................................................... 734.1.3 Data definitions ..................................................................................................... 734.1.4 Common Data....................................................................................................... 734.1.5 Charging Matrix Data Exchange............................................................................ 744.1.6 Charging Matrix Validation.....................................................................................754.1.7 Dynamic Charging Data ........................................................................................764.1.8 Batch Sequencing Signals..................................................................................... 764.1.9 Communications Monitoring and Coordination....................................................... 784.1.10 Inserting Extra Material......................................................................................... 794.1.11 Communications Back-up Signals ........................................................................ 79

4.2 BLT Discharge Log..................................................................................... 794.3 Stockline Level Control System.................................................................. 81

4.3.1 Stockline Selection................................................................................................ 814.3.2 Non-contact Stockline (Radar)............................................................................... 824.3.3 Mechanical Stockline............................................................................................. 82

5 H YDRAULIC FUNCTIONAL DESCRIPTION .............................................................84

5.1 Hydraulic System Overview........................................................................ 845.2 Hydraulic System Operating Modes ........................................................... 84

5.2.1 Automatic Mode .................................................................................................... 845.2.2 Manual Mode ........................................................................................................ 855.2.3 Local Mode ........................................................................................................... 85

5.3 Detailed Device Operation and Interlocks................................................... 855.3.1 Hydraulic Tank Monitoring..................................................................................... 855.3.2 Hydraulic Pressure Pumps .................................................................................... 855.3.3 Hydraulic Return Line Filter ................................................................................... 865.3.4 Hydraulic Circulation Pumps.................................................................................. 875.3.5 Hydraulic Cooler.................................................................................................... 875.3.6 Hydraulic Circulating Filter..................................................................................... 88

5.4 Hydraulic HMI Controls............................................................................... 88

6 G REASING FUNCTIONAL DESCRIPTION ..............................................................89

6.1 Greasing Operating Modes ........................................................................ 896.1.1 Automatic Mode .................................................................................................... 906.1.2 Manual Mode ........................................................................................................ 906.1.3 Local Mode ........................................................................................................... 90

6.2 Central Grease Pumps with Grease Reservoir ........................................... 906.3 Grease Valves............................................................................................ 91

6.3.1 Change Over Valves ............................................................................................. 91





1 General Descript ion

1.1 Reference Documents

Document PW Number Customer number AUTOMATION SYSTEM DESCRIPTION D-00020616MCL LIST D-00020642INSTRUMENTATION LIST D-00020646P&I DIAGRAM BLT PROPER 5018004-0406423P&I DIAGRAM PLANETARY GEARBOX 5018004-0406985P&I DIAGRAM PRESSURE EQUALIZINGSYSTEM

5018004-0406986

STOCKHOUSEMATERIAL TIMING DIAGRAM

5018004-04062375018004-0406245

5018004-0406248TWO HOPPER BELL LESS TOPFALLING CURVES DISTRIBUTION

5018004-0406013

P&I DIAGRAM TOP HYDRAULICS 5018004-0406988P&I DIAGRAM TOP LUBRICATION 5018004-0406989BLT STEAM HEATING SYSTEM - 2H - N 594-0402102P&I DIAGRAM WATER COOLINGSYSTEM

5018004-0406987





1.2 System Overview

The following is a sketch of the Bell Less Top ® Charging System





1.3 Bell Less Top® Charging System Description

The Bell Less Top ® Charging System is an automated system designed to:

Receive batches from the stockhouse of ore, coke and miscellaneous materialsin the Bell Less Top ® Charging System Material Hoppers

Discharge those batches, as required, to a continuously rotating chute locatedbelow the Material Hoppers

Distribute material through pre-selected Chute Tilt positions, to the furnace topstockline surface for charging of the Blast Furnace.

To perform these functions, the system includes equipment and process control for theBell Less Top ® Charging System, as well as equipment and control for associatedsystems:

water cooling; nitrogen for pressurization and cooling; hydraulics for actuation of all valves in the Bell Less Top® Distribution System; grease for automatic lubrication of valves and gearbox components; and steam

heating for the upper and lower seal valve seats to prevent moisture and dirtbuild up on the seats.

1.3.1 Charging CapacityThe BLT’s charging capacity is based on the size of the lock hoppers, ring pattern, and flow ratethrough the Material flow gate. As well the Stockhouse capacity to deliver batches to the BLT canalso limit the charging capacity.

These key parameters for the BLT are list in the Table below.

Description ValueMaximum Number of Lines in the Matrix 20Working volume of lock hopper 80m3Material Flow Gate minimum flow rate 0.2 m3/sMaterial Flow Gate maximum flow rate Coke 0.8 m3/sMaterial Flow Gate maximum flow rate Pellets or Sinter 0.8 m3/sChute length 4.5mNormal charging cycle C/ONormal cycles per day 138

1.3.2 Performance CriteriaThe purpose of the BLT is to accurately and in a repeatable manner deliver and distribute thematerial from the lock hoppers onto the top of the furnace burden. This is measured by deliveringthe material to the furnace in the required discharge time with the chute at the correct angleDuring normal operation the key performance criteria are

- Discharge time will be +/-5% of the target time- Chute tilt positioning accuracy of 0.1 deg and a max speed of 1.6°/s- Material gate positioning accuracy of ± 0.1° and a max speed of 15°/s





1.3.3 Mechanical Equipment of Bell Less Top

Distribution Rocker

BLT-MR-DR

The Distribution rocker receives the material coming from thestock house by conveyor belt and has a tilting movement in order to transfer this material into the hoppers 1 or 2.

Material Hoppers

BLT-MHO-01,BLT-MHO-02

Material hoppers are two chambers, Material Hopper 1 and 2 thataccept material from the Distribution Rocker. These two hoppers,store material to be discharged into the furnace. They operate asgas locks, in that they allow the charging of solids into apressurized furnace without the loss of gas. Each material hopper

is mounted on load cells for weighing the material in the hopper Upper Seal Valves

BLT-MHO-01-USV,BLT-MHO-02-USV

These valves are installed on the upper part of each hopper inorder to close the material entrance and to ensure the gas-tightness of the hopper. This valve opens to accept materialdischarging from the tilting receiving chute, and closes after thematerial hopper is filled with a material batch.

Primary EqualizingValves

EQU-01-PEV,EQU-02-PEV

These valves permit the pressurizing of the material hopper withsemi-clean blast furnace gas.

SecondaryEqualizing Valves

EQU-01-SEV,EQU-02-SEV

These valves permit the pressurizing of the material hopper withnitrogen slightly above BF pressure, as well as dust suppressionduring material charging into the Bf by compensating the amountof discharged material with nitrogen.

Lower Seal Valves

BLT-MHO-01-LSV,BLT-MHO-02-LSV

There are two lower seal valves, one for each material hopper,installed in a common valve casing. During the filling of materialinto the blast furnace these valves are open. During the materialfilling into the hopper these valves seal the blast furnace top fromthe atmosphere.

Material FlowControl Gates

BLT-MHO-01-MFCG,BLT-MHO-02-MFCG

The material flow control gates are installed each in a casing, onegate for each hopper. The material flow control gates control thematerial flow coming out of the material hopper.





Distribution Chute:

CTG-ROT,CTG-TILT

The distribution of the material into the blast furnace is performedby tilting and rotation movement of the chute. The rotating chutetilts to one of 11 preset angles to direct the flow of material to adesired location.

Relief Valves

EQU-01-RV,EQU-02-RV

Each material hopper has a relief valve: (RV). The function of thisvalve is to depressurize the material hopper to atmosphericpressure following a batch discharge to the furnace. The relief valve opens after the lower seal and material gate have closed,and while the next Load is in transit to the furnace top. It closeswhen the upper seal valve begins to open. Material hopper pressurization begins when both the relief valve and upper sealvalve are closed.

Goggle Valve:

BLT-GV

The goggle valve is used to isolate the BLT hoppers from the BFduring maintenance stops.

Addi tional Bell -Less Top equ ipment includes:

Gearbox This is a large structure above the chute that houses gears andassociated assemblies for rotation and tilting of the distribution chute.The gearbox also includes an upper trough that accepts cooling water and nitrogen; and a lower trough that collects cooling water from thecooling panels prior to discharge.

WeighingSystem

Each material hopper is equipped with a three load beam system thataccurately reports material weight during filling and discharge of thematerial hopper. During filling, the weighing system verifies materialweight and signals that the material hopper is full. During discharge,data from the weighing system aids in calculating the opening of thematerial flow gate. In normal operation, the weighing system and sonicdetector are used to determine that the material hopper is emptyfollowing material discharge to the furnace. The weighing system hasa pressure compensation system to account for uplift on the hopper when pressurized

SonicDetectors Located below the lower seal valve of each material hopper is a sonicdetector that detects shock waves produced by material flowing fromthe material hopper to the distribution chute. Analog signals from thesonic detectors are transmitted to the Bell-Less Top Controller, andsoftware thresholds are used for material flow detection. Differentvalues are stored for coke or other burden material; for example,pellets have a higher sonic level than coke. Also, the material hopper 1may have higher or lower sonic signals than the material hopper 2.

The absence of flow via the sonic detector, along with a “0” flow rateindication and an “Empty” signal from the weighing system, indicatethat the discharge is complete and the hopper is empty. If the

weighing system is out of service, signals from the sonic detector are





used in conjunction with time-based discharge to determine that thematerial hopper is empty. Sonic detectors are also instrumental indetermining that a material bridge has occurred.

1.3.4 Bleeder Valves

Four Bleeder Valves are located at the furnace top (02-BF-BLE-01 through 02-BF-BLE-04). The bleeders are designed to open 2 to 3 seconds to depressurize any pressurepeak at the furnace top. The control of the Bleeder Valves is outside of the scope of BLTController and belongs to BF Controller.

1.4 Process Sequence

Each Material Hopper runs the identical sequence but at different times. Typically whenone hopper is being filled the other hopper will be discharging. In normal operation theBLT only waits for the discharge trigger based on Stockrod level. Therefore the only timea hopper sequence pauses is when it is full and pressurized and burden level is above

the discharge level.

The following table provides a summary of the steps. Step 0 has the initial conditionsthat the hopper is empty and the MFCG and LSV have just closed but the hopper is stillpressurized.

Step Sequence Action Description

1 Relieve Open RV Relieve the hopper to atmosphere

2 Prepare for material

Open USVand close RV

Prepare hopper to receive material. RV starts toclose as USV starts to open. RV should be

closed when filling to keep dust out of valve andpiping.

3 Tare Hopper Tare hopper empty at atmosphere

4 Move DR toHopper

Position Distribution rocker to hopper waiting for material

5 Fill Fill Hopper Stockhouse will set flag that material is at topand when flag goes off hopper weight shouldstop increasing

6 CompareWeight

The weight the stockhouse sent should be with intolerance of weight on top

7 Move DR tocentre

Position Distribution rocked back at centreposition so USV can Close. This keeps materialfrom falling on to the USV

8 Close USV Close upper seal valve so system can beequalized to furnace

9 Equalize Open PEV Equalize hopper until close to furnace toppressure





10 Close PEVCheck WeightCompensation

Primary equalizing valve must close soSecondary equalizing valve can regulatepressure to match BF top pressure. Weight inhopper should match weight just prior toequalizing

11 Open SEVs Regulate hopper pressure to slightly abovefurnace top pressure.

12 Wait for discharge

Wait until burden level requires materialdischarge to furnace and other hopper is not nextto discharge

13 Discharge Open LSV Open lower seal valve

14 Open MFCGand regulateSEV

Open material flow gate to correct position basedon required volumetric flow. Regulate the SEV tofill hopper with nitrogen as material is dischargedto help keep out dirty BF gas

15 Wait for empty Wait for Sonic and hopper weight to indicateempty

16 Open MFCGto 90 deg

Open MFCG all the way to verify all material isoff back of MFCG

17 Close MFCG Close Material flow gate

18 Close LSV,Close SEV

Close the lower seal valve and the secondaryequalizing valve

When the last step is reached the system cycles to the first step. The two places thesequence waits is when waiting for material from the stockhouse or when waiting for thedischarge trigger based on burden level.

1.5 Auxiliary Systems of the Bell less Top

1.5.1 Hydraulic System Overview

The Bell-Less Top hydraulic system maintains hydraulic pressure to all primary Bell-LessTop valves (upper seal valves, equalizing valves, secondary equalizing valves, relief valves, lower seal valves, material flow gates, goggle valve, distribution rocker, planetarygearbox grease valve, and bleeder valves). It consists of an oil tank, filtering and coolingcircuit, two pressure pumps, and accumulator station.

1.5.2 Water Cooling System Overview

The Bell-Less Top closed loop water cooling system is supported by two circulationpumps (one in operation, one as standby) that maintain a continuous water flow rate of 25 m 3/hr. Due to normal water loss from evaporation, leaks and flushing requirements,make-up water is added to the system as needed.

In this closed loop circuit, process water is pumped from a reservoir through a self-cleaning hydro-cyclone filter to a water/water heat exchanger. On the secondary side of the heat exchanger, service water circulates to cool the process water.





Cooled process water travels from the heat exchanger to the upper rotating trough of thechute transmission gear. From there, it flows by gravity through the serpentines to thelower static trough of the chute transmission gear. The accumulated process water isthen routed back to the process water reservoir.

The cooling system must operate continuously, even during blast furnace shutdown.Cooling is stopped only when working on the cooling circuit. In the event of anemergency, process water cooling can be suspended for a maximum of six hours duringblast furnace operation, with the furnace top cooled via emergency nitrogen. Operatorsmust continually monitor temperatures in the chute transmission gear while the coolingsystem is non-operational.

1.5.3 Gearbox Nitrogen and Purging

The main gearbox is pressurized with nitrogen to prevent blast furnace gas and dustfrom entering the main gearbox housing. This pressurization is accomplished by amechanical flow controls and manual valves. There are no electrical controls associated

with the gear box pressurizing nitrogen, however there is monitoring of the critical valvesas well as monitoring of the incoming nitrogen pressure, temperature and flow. An air purge fan is installed on the gearbox and valve actuation unit nitrogen cooling system.The fan is run when whenever maintenance is preformed in these areas to ensure thenitrogen is removed and there is oxygen available

In the event of a failure of the cooling water system the main gearbox can be cooled withnitrogen.

In the event of an over temperature (above 120 deg C) in the Valve Actuation Unit theemergency nitrogen cooling valve will open.

1.5.4 Steam Heating

The upper and lower seal valves are heated to prevent condensation on the seats If condensation forms on the seats the dust in the gases and materials will stick to theseats and cause premature wear.

1.5.5 Greasing

The BLT has an automatic greasing system to provide lubrication to critical componentson the Furnace Top. The system consists of two different greasing zones each operatesindependently using a common pair of pumps and grease tanks. The zones grease the

following areas

Fast Zone: cycles every 45 minutes (chute transmission and planetary gear) Slow Zone: cycles every 8 hours (stockline winch, lower seal valve, lower

material gate, upper seal valve, upper material gate, equalizing valve, relief valve, distribution rocker, bleeder valves and conveyor belt).

The chute and gearbox have individually monitored grease points while Slow Zone onlymonitors the end of line switches.





1.6 Nomenclature

Burden - A burden is a compilation of all data required for the blast furnace to producehot metal. The burden includes charge material names, weights and chemistries;furnace aims such as hot blast temperature and volume, raw material charge rate, slagchemistries, and hot metal temperatures and chemistry. While multiple burdens can becreated for a furnace, there is one and only one Active Burden.

Charge - A charge is a collection of raw materials, ore and coke, containing all of thechemical requirements in the proper balance for producing iron. However, a charge isnot necessarily all of the burden materials used. The most efficient charging sequencesfor the Bell-Less Top utilize two full lock hopper loads for a complete charge.

Round - A round is a self-contained sequence of charges that, in total, contain all of theburden materials used in the correct proportions. When the sequence of chargesrepeats, the next round begins. A round can be one charge or multiple charges. An

Active Charging Matrix contains all of the recipe parameters and setpoints for an entire

round. A round can be one charge or multiple charges. A single-charge round includesall of the burden materials needed to meet the desired chemistry. This is beneficialbecause it promotes process uniformity within in the furnace. A multiple-charge roundprovides the flexibility to add smaller amounts of materials that would normally fall belowthe lower limits for proper weighing in a coke batch or an ore batch.

Charging Matrix - The Charging Matrix, which is derived from the burden, is a recipethat details all batches, charges and rounds for charging the Blast Furnace. The ActiveCharging Matrix contains a sequential list of batches that define the raw materials, theraw material target weights and the furnace top discharge control parameters. Thecharging system uses the Active Charging Matrix data in the raw material weighingsequences and in the discharge sequences that control the delivery of the raw materialinto the furnace on a batch-by-batch basis, to maintain a consistent stockline.

Next Charging Matrix – The Next Charging Matrix, is a location for loading an entirecharging matrix from the level two system or creating and editing a matrix through theHMI. The next matrix can be accepted for running at which point the active matrix willfinish its current round and then continue on the new matrix. Since the stockhouse worksahead of the BLT the stockhouse will start the new matrix before the BLT allowing for changing the complete charging matrix without delaying the charging of the furnace.

Active Charging Matrix - The Active Charging Matrix, is the charging matrix currentlyrunning on the furnace. It can be edited as the furnace is running but any line that is

currently in the process of being weighed by the stockhouse or delivered to the furnacecan not be edited.

Batch - The stockhouse system controls the discharge of the weigh hoppers onto theFurnace charging belts which transport the raw material to the furnace top. A batch is acollection of raw materials distributed on the Furnace charging belts in one dischargesequence corresponding to one line of the Active Charging matrix.

Position - A position is a preset tilt position (angle) of the rotating distribution chute onthe furnace top. Each position directs the flow of material to a desired location in thefurnace. There are 11 positions for charging the Blast Furnace, position 1 is nearest theblast furnace center and position 11 is nearest the blast furnace shell.





Portion - The total weight of each material hopper load is divided into portions for distribution to specific positions. Each portion is an equal quantity, and each position canhave one portion or multiple portions. Only a full number of portions per position isacceptable. The Active Charging Matrix defines the positions for distribution and thenumber of portions per position.

Burden Level – The current level of the materials in the Blast Furnace. This level ismeasure either through mechanical Stodrods or radar level detectors and used to trigger the discharge of a material hopper into the furnace.

Discharge Level – The Burden level that a material hopper is discharged is triggered.

Catch-up offset – offset added to the Discharge Level below which BLT switches to“catch-up” mode. It will request new batches with maximum frequency ignoring PreferredHopper information.

Checkpoint P1 – is used to start the top preparing to receive the batch. Therefore itneeds to be the point on the belt where the travel time to the final checkpoint P2 is justslightly longer than the time for the top to get ready for a batch. This time is calculated asthe relief time plus the Upper Seal Valve opening time plus the distribution rocker traveltime.

Checkpoint P2 – is the point on the belt where if the BLT is not ready for the batch thenthe Stockhouse belts must stop to prevent dumping material on a closed lock hopper.





2 Automation and Control System Hardware

2.1 Control philosophyThe BLT is a completed automated system requiring minimal operator intervention.

Normal operation of the BLT is through the HMI screens in the main control room. TheHMI is a client server system with redundant servers to provide for a high level of availability. The BLT operator screens will be part of the overall Blast Furnace HMIsystem.

Redundant Controllers are used to monitor and control the complete BLT, and providethe interface to the rest of the blast furnace. It is located in the main Blast Furnaceelectrical room. Remote Input/Output (I/O) racks are used to receive and transmitprocess data and control signals. The remote I/O is located in the main electrical room

There are four modes of operation for the BLT, they are; Automatic (normal mode system sequences as required) Semi-automatic ( sequences run as in auto but they are initiated by the operator) Manual (none operational mode allows operator to control individual devices with

process interlocks present) Local (none operational mode allows operator to control individual devices from

the local control stations with only safety interlocks present)The following table shows which modes apply to the each subsystem

Auto Semi-auto Manual LocalBLT proper x x x xHydraulic x x xGreasing x x xGearbox Cooling x x xSteam Heating x x

The detailed description of each mode as it relates to each subsystem is included in thefunctional description of the subsystems later in the document.

2.1.1 Local control

Local controls are provided for Maintenance purposes only. The BLT is operatedremotely and normally no personnel are near the equipment when it is in operation.Therefore the local controls are only intended for use when the furnace is down or for equipment troubleshooting.Local status information and control is provided through Local maintenance pushbuttonstations are located near the major BLT devices and individual motors.





2.1.2 Failure analysisThe BLT is critical to the charging of the furnace and therefore is designed with a highdegree of reliability. Therefore both mechanical and electrical redundancies have beenprovided to increase the reliability. All critical pumps are paired and the I/O for the

pumps must be in different racks.In the event of a failure that does require a shutdown hydraulic accumulators are usedso the Material hoppers can be put in a safe state.If both hydraulic pumps pressure pumps fail the Controller will allow any discharge inprogress to complete and close the lower seal valve and leave the hopper pressurized.

Any fills will be allowed to continue and once complete if possible then the distributionrocker will move to centre and the Upper seal valve will close.

A failure in the cooling water system is protected with an emergency nitrogen coolingsystem.If there is a mechanical failure in a single material hopper then the other hopper can be

used to charge the furnace at a slightly reduce rate.

2.1.3 Relationship to StockhouseThe BLT receives the burden materials from the stockhouse. It is the Stockhouse’sresponsibility to ensure that the materials in the burden are accurately weighed anddelivered to the BLT when requested.The stockhouse is the master of the recipe and as such it sends the BLT the burdeninformation this includes a valid ring pattern for the material being delivered. In case of an error the BLT also validates the ring pattern vs the material delivered uses thematerial hopper weigh scales to verify the amount of material delivered by thestockhouse matches the burden information sent by the stockhouse. In the event of acommunications failure the BLT will continue to deliver batches based on the matrixstored in the BLT Controller memory and wired I/O signals to the stockhouse.

A full description of the Stockhouse BLT interface is included in Section 4.1

2.1.4 Diagnost ics and data loggingThe BLT control system is provided with advanced diagnostics and logging capabilities.The BLT control system

- Monitors the current and average time of critical movements and alarms if they are out of normal tolerance

- logs and buffers the information about the distribution of each discharge tothe furnace

- provides pre-configured trends of critical operation such as chute tilt androtate positions and motor currents

These features are described in details later in the document





2.2 System ArchitectureThe Automation system is based on the ABB 800xA System platform. The HMI is part of the overall Blast Furnace Control system. The MCC will be a smart MCC on Profibuswith wired inputs and outputs for the run and running feedback.

2.2.1 RedundanciesThe control system is designed for a high level of availability. Some items that havebeen used to accomplish this are;

Redundant Controller processors – if an individual Controller or network cardfails then the redundant processor is used as a back-up system

Dual cable I/O network – a dual cable I/O network is used to provide two pathsto all the remote I/O racks. These cables should be routed separately to insurethat if one cable is physically damaged the other cable will still be intact. Theyshould be run in separate cable trays and conduits.

Pairs of Controller RIO racks – where there are mechanical redundancies (dualpumps, two lock hoppers) then the I/O related to these devices are housed inseparate Controller racks this means the failure of a single Controller rack,communications card or I/O card will not cause the entire BLT to be unavailable.

The Controller processors as well as any critical I/O are backed up by a UPS.





2.2.2 Control System Diagram

The above diagram is a conceptual representation of the PLC architecture for the exact PLC andnetwork layouts Please refer to the ABB network drawings. 2B0987D1-R216-K0001

2.2.3 Controller ComponentsThe Controller will be ABB AC 800M, with S800 I/O. The VVVFs drives will be ACS8000series..

2.2.4 HMI InterfaceHMI will be developed to be part of the overall BF HMI system. The HMI will be

programmed using 800xA system version 5.0 SP2 with PG2 5.0.2 The top header area will

PLC

HSBY

By Customer

PLC ROOM

MCC ROOM

HYDRAULIC SYSTEM

GREASING SYSTEM

COOLING SYSTEM

RIO

RIO

RIO

RIO

VVFD 1

Weighing Hopper 1

Tilt1

Tilt2

Rotate 1

Rotate2

RIO

VVFD 2

VVFD 3

VVFD 4

CustomersProcessEthernet

Programming Laptop

Chute and MFG Encoders

Profibus / DeviceNet

Weighing Hopper 2





CHARGING DECK

I / O N e t w o r k

( c o p p e r )





be shared by all HMI screens the middle area will be for the process screens and thebottom are will have a navigation button bar that changes based on which area theoperator is looking at.

2.2.5 Interfaces to Other Systems

2.2.5.1 St ockhouse Int er face

The interfaces to the stockhouse Controller will be a combination of wired and networkedsignals. The stockhouse and BLT Controllers must be on the same Ethernet network.The stockhouse interface is described in Section 4 of this document.

2.2.5.2 St ockrod int erf aces

There will be two Radar Stockrods and one mechanical Stockrod.Radar Stockrods will be wired directly to the BLT Controller analog inputs and will each

have one fault contact to indicate over temperature.The Mechanical Stockrods will be interfaced, using a combination of wired I/O signalsand Profibus. The following table is based on TMT standard StocklineSignal TypePosition Input, analog 4-20 mA

At Dismantling position Input, digital At Minimum position Input, digital At Maximum position Input, digitalOn Burden Input, digitalStockrod Motor over temperature switch OK Input, digital

Dynamic brake resistor over temperature switch OK Input, digitalDrive Healthy Input, digitalDrive Remote control Output, digitalLower command Output, digitalRaise command Output, digitalCalibrate command Output, digital

The final interface is to be defined based on Stockline supplier.





2.3 Panel Block DiagramThe following diagrams shows the panels and their locations

The above drawing is conceptual for exact panel list refer to ABBs detailed electrical design.

2.3.1 Voltage levelsType ValueMotors 415VAC 3ph 50hzMCC controls 24VDC with interposing relays to customer

chosen voltageDigital Inputs and outputs 24VDC

Analog inputs and outputs 4-20mATemperature inputs RTD

Main PLC Panel2000h x8 00 w x800d

MCC

All pumps and motors

Wired I/O

I/O Network (copper)

Tilt Motor /wBrake and

1024ppm puls eencoder

Rotate Motor c/wBrake

Load Cells connected toweighing transmitter

transmitters and sensorsrelated to BLT hoppers

Chute and MFG Encoders

CHARGING DECK

Max cable length300 m

W i r e d

MCC ROOM MAIN ELECTRICAL ROOM

I/O Network (copper)Greasing I/O andHydraulics I/O Panel

2000H x 1600W x 800D


Cooling I/O Panel2000H x 800W x 800D

Main I/O andWeighinig Panel

2000H x 800W x 800D

MCC I/O Panel2000H x 800W x 800D



P r o f i b u s

/ D e v i c e N e t

W i r e d

Valves, transmitters andsensors local to HPU

Valves, transmitters andsensors local to Greasing

Valves, transmitters andsensors local to Cooling

W i r e d

Chute Tilt and Rotate Drives2000H x 1600W x 800D






2.3.2 Wiring StandardsThe following is short list of key wiring practices that must be followed

Inputs and outputs internal to apanel

The power feed to each I/O card will be protected with fuse or circuit breaker

Field Inputs and outputs All I/Os to field devices (wiring leaves panel) will be individuallyfused

Analog Inputs cards Will be non isolated and should accept the HART protocol if available

Analog inputs Will be wired f rom the I/O card to the terminal blocks to support2,3, or 4 wire transmitters all terminal related to each analogpoint will be together on the terminal strip.

Outputs to valves and starters Will be wired to terminal block style relays to allow for thehigher current required. And to allow all outputs to be 24VDC

regardless of field voltageRTD wiring All RTD inputs will be wired to terminal blocks

2.3.3 Controller panelThe Controller panel contains the redundant Controller processor racks and the I/O andHMI network communications cards. The panel must be powered by the UPS power supply.

2.3.4 Main I/O PanelThe main I/O panel contains the I/O from the BLT field devices this includes the I/Orelated to the operation of the Material hoppers, gearbox and distribution chute. Thepanel is located at the base of the furnace (ground level), in the main electrical room.Wire length for I/O and some electronics to the top becomes and issue if the panel is toofar from the BLT. The weighing transmitters should be located in the door of this panel.The approximate I/O count for this panel, not including spares, is in the following tableType QtyDI 59DO 21

AI 6 AO 0RTD 0Profibus 2

2.3.4.1 Wei ghi ng Equipment

The weighing transmitter will be a Schenck DISOMAT Tersus in VEG20450 rack withProfibus-DP module VPB 8020





The Load beam junction will be a DKK69

One digital output from the scale will be wired to the Controller to indicate the scale ishealthy

The Controller reads the scale weight, and status information from the scale over theProfibus network.The data read from the scale will be

Gross weight Weight steady Fault class and fault number dW/dt (flow rate) used for information only

2.3.5 Motor Power Panel MCC

The MCC will be a smart MCC on Profibus for status monitoring. Each motor will have awired run signal, a wired running feedback and a wired faulted signal. The network willbe a simplex cabled network on copper media.The MCC power feed must be on a reliable source as it is critical to the operation of theBLT.This can be accomplished with an automatic transfer switch in the customer distributionnetwork or at the BLT MCC by means of a low voltage automatic transfer switch and twoseparate power feeds to the MCC.

The motors to be fed from the MCC are listed in the MC list.

Each motor will have the following signals exchanged with the Controller.Signal description Type Voltage/ RangeSafety Interlock Hardwired Dry contact from relaysRun Command from Controller Wired 24VDCRunning feedback toController

Wired 24VDC from dry contact

MCC Fault Wired 24VDC from dry contactOverload Network 1 = overloadPower OK Network 1 = power OKMotor Current Network xxx.x AmpsMotor over temperature(thermisters) if installed onmotor

Network 1 = over temperature

2.3.6 MCC I/O panelThe MCC I/O will be wired to the MCC I/O panel. This panel will be located at the MCCand will house the Controller I/O cards related to the MCC. The MCC I/O will be dividedbetween two racks so that any single failure will not cause the BLT to fail. Two racks





allows any mechanically paired items to be wired to separate racks and cards to providea higher level of availability.The approximate I/O count for this panel, not including spares, is in the following table

Type QtyDI 71DO 22

2.3.7 DrivesThe chute tilt and chute rotate are critical to the operations of the furnace. These motorsrequire precise control therefore they are powered with redundant VVVF drives.The motors have the following characteristics.

Nominal power rate : 18.5kWVoltage : 415V 50 Hz / 3 phasesNominal current : 23 / 38.5 ADisc brake type : 110 V DC / 1,44 A / 158 WEncoder type : absolute

The drives will be ABB ACS8000 drives





2.3.7.1 Drive Sing le Line Diagram

Single line diagram of the drives is provided below. The drives have both incoming andout going contactors and isolation switches to provide remote selection of the activedrive. Therefore the drives can be switched from the control room in the event of afailure. The manual isolation switches provide the isolation of power wiring of one drivefrom the other allowing for maintenance on one drive while the other drive is running.

Size of fuses and drives based on motor sizeLine and load reactors based on distance from drive to motor

M

ChuteGearbox

Absolute Encoder/Resolver x2

Encoder

Fuse

FusedDisconnect

InputContactor

VVFDflux vector AC drive

BrakingResistor

OutputContactor

OutputDisconnect

Fuse

FusedDisconnect

InputContactor

VVFDflux vector AC drive

BrakingResistor

OutputContactor

OutputDisconnect

LocalDisconnect

BrakeContactor

Fuse

FusedDisconnect

Brake Rectifier

Profibus/DeviceNet

Line Reactor Line Reactor

Brake





2.3.7.2 Chute tilt driveVoltage 3phase 415VAC 50hzCurrent 23 / 38.5 ANetwork ProfibusLine reactor (if required based on distance) 3% (sized by electrical designer based on

distance to motor)Load reactor (if required based on distance) 3% (sized by electrical designer based on

distance to motor)Dynamic Brake resistor Electrical designer to size for 8 stops per

minute 480 per hour

2.3.7.3 Chute Tilt I/O

The following table lists the discrete I/O for the chute tilt drive

Signal Input/Output TypeE-Stop on Drive Panel Input RIO, Drive hardwiredMain Disconnect 1 Open Input RIODrive 1 Input contactor closed Input RIODrive 1 Output Contactor closed Input RIODrive 1 Output Disconnect open Input RIO, Drive HardwiredDB Resistor 1 Over temperature Input RIOMain Disconnect 2 Open Input RIODrive 2 Input contactor closed Input RIODrive 2 Output Contactor closed Input RIO

Drive 2 Output Disconnect open Input RIO, Drive HardwiredDB Resistor 2 Over temperature Input RIOMotor Over temperature Input RIOBrake Release Output DriveDrive 1 Select Output RIO and relay wired to

drive contactorsDrive 2 Select Output RIO and relay wired to

drive contactors At Dismantling Position Input RIO, Drive hardwired to

by-pass high limitLocal Motor Disconnect (Early breakcontacts)

Input RIO, Drive hardwired

Chute Tilt Overtravel Low-Low Limit Input RIO, Drive hardwiredChute Tilt Overtravel High Limit (is end of travel limit for chute unless in thedismantling position


Chute Tilt Overtravel High-High Limit Input RIO, Drive hardwired

The Chute tilt drive will also have the following position feedback devices

- Networked absolute encoders (Profibus) with 13 bit resolution per revolution(4096 counts/rev)





2.3.7.4 Chut e Rot at e dr iveVoltage 3 phase 415VAC 50hzCurrent 23 / 38.5 ANetwork ProfibusLine reactor (if required based on distance) 3% (sized by electrical designer based on

distance to motor)Load reactor (if required based on distance) 3% (sized by electrical designer based on

distance to motor)Dynamic Brake resistor Electrical designer to size for 2 stops per hour

2.3.7.5 Drive I/O

Since the drives are networked there will be minimal I/O wired between the drive and theController. The I/O will be located in the main I/O as it is the closest panel to drives. TheI/O wired will beChute Tilt driveSignal Input/Output TypeE-Stop on Drive Panel Input RIO, Drive hardwiredMain Disconnect 1 Open Input RIODrive 1 Input contactor closed Input RIODrive 1 Output Contactor closed Input RIODrive 1 Output Disconnect open Input RIO Drive HardwiredDB Resistor 1 Over temperature Input RIOMain Disconnect 2 Open Input RIODrive 2 Input contactor closed Input RIODrive 2 Output Contactor closed Input RIO

Drive 2 Output Disconnect open Input RIO Drive HardwiredDB Resistor 2 Over temperature Input RIOMotor Over temperature Input RIOBrake Release Output DriveDrive 1 Select Output RIO and relay wired to

drive contactorsDrive 2 Select Output RIO and relay wired to

drive contactorsLocal Motor Disconnect (Early breakcontacts)


The Chute Rotate drive will also have the following position feedback devices

- Networked absolute encoders (Profibus) with 13 bit resolution per revolution(4096 counts/rev)

2.3.7.6 Chute Tilt and Rotate Isolat ion Switches.

The chute tilt and rotate drives have lockable isolation switches at the motors. Theseswitches require early break low voltage contacts to be hardwired in the drive enablecircuit as well as to the Controller for alarm and control.





The power contacts must be rated for 100 Amps but do not need to be load break ratedbecause of the early break contacts. Electrical designer must verify switch meets alllocal code requirements.

2.3.8 Operator control st ationsLocal Maintenance Pushbutton stations will be provided at each of the major BLTdevices. These will allow the Maintenance personnel to move the device as requiredduring maintenance functions. The following panels will be provided





2.3.8.1 Dist ri but ion Rocker

Description DeviceLocal Remote Selector Selector switchLocal Light Indicating Light (yellow)To Hopper 1 PB PushbuttonTo Centre PB PushbuttonTo Hopper 2 PB Pushbutton

2.3.8.2 USV, LSV, RV, PEV, SEV-SV, MFCG local panels

Each of the USV, LSV, RV, PEV, SEV-SV, MFCG have a local control station with thefollowing controls.

A total of 12 pushbutton panels are needed.

Description DeviceLocal Remote Selector Selector switchLocal Light Indicating Light (yellow)Open PB PushbuttonClose PB Pushbutton

2.3.8.3 Moto r Local Panels

Local control of the motors is provided through the Local Pushbutton stations. The each

motor will have a Local Pushbutton stations. The wiring of these stations and exactquantity are shown in the Danieli Corus MCC drawings. The motor local stations willhave the following devicesDescription DeviceLocal Remote Selector Selector switchLocal Light Indicating Light (yellow)Start PB PushbuttonStop PB Pushbutton





2.3.8.4 Goggle Valve Local Panel

The goggle is only controlled in local mode

The goggle valve local station will have the following devicesDescription DeviceLocal Remote Selector Selector switchLocal Light Indicating Light (yellow)Clamp PB PushbuttonUn-clamp PB PushbuttonOpen PB PushbuttonClose PB Pushbutton

2.3.8.5 Chut e Local Panel s

The chute tilt and rotate has two Local Control Panels one at the gearbox elevation andone at the dismantling door elevation. They have the following operator controls.

Chute Tilt and Rotate Local Panel

Chute E-stop(at local panel)Hardwired to stop tilt drive and rotate starter also I/O signal to Controller

Local/Remote Selector

Selector Switch to choose method of control for the Chute

- Local allows the local manual controlfrom this panel or the dismantling panel.

- Remote allows the control from HMI or as dictated by the Controller.

Local LightIndicates Chute is in Local Mode and buttons onthe local panels are enabled

Chute Rotate Fast to CCW PBIn local causes chute to Rotate Fast CCWChute stops when button is released

Chute Rotate Fast to CW PBIn local causes chute to Rotate Fast CWChute stops when button is released

Chute Rotate Slow to CCW PB at local panelIn local causes chute to Rotate Slow CCWChute stops when button is released

Chute Rotate Slow to CW PB at local panelIn local causes chute to Rotate Slow CW Chute

stops when button is releasedChute Tilt Up (at local panel)

In Local causes chute to jog upward at a slowspeed. Stop when release

Chute Tilt Down(at local panel)In Local causes chute to jog downward at a slowspeed. Stop when release

Chute rotate at dismantling Position Light (atlocal panel)

Indicates chute rotate is at the dismantling limitswitch

Local panel / Dismantling panel selector Allows switching control between Local andDismantling panels when in the Local mode





Chute Tilt and Rotate Dismantling Panel

Chute E-stop(at dismantling panel) Hardwired to stop tilt drive and rotate starter

Chute Rotate Slow to CCW PB at dismantlingpanel

In local causes chute to Rotate Slow CCWChute stops when button is released

Chute Rotate Slow to CW PB at dismantlingpanel In local causes chute to Rotate Slow CW Chutestops when button is released

Chute Rotate Go to Dismantling positionSends chute rotate to dismantling position. Slowspeed is used.

Chute Dismantling (Key Switch) Selected Along with dismantling limit switch this bypassthe chute tilt cam switch

Chute Tilt Up (at dismantling panel)In Local causes chute to jog upward at a slowspeed. Stop when release

Chute Tilt Down(at dismantling panel)In Local causes chute to jog downward at a slowspeed. Stop when release

Chute rotate at dismantling Position Light(at

dismantling panel)

Indicates chute rotate is at the dismantling limit

switch

2.4 Emergency Stops

The E-stops on the BLT are affected only to the system they are related to.

The following table list the hardwired E-stops;

E-stop Location Devices AffectedCooling Water Pump1 LCP Cooling Water Pump1

Cooling Water Pump 2 LCP Cooling Water Pump2Nitrogen Purge Fan LCP Nitrogen Purge FanTwo E-Stops in Hydraulicscontrol room – one next toeach door

Hydraulic Pressure Pump1Hydraulic Pressure Pump2Hydraulic Circulation Pump1Hydraulic Circulation Pump2

Hydraulic Pump LCP Stops associated hydraulic pump.Greasing Pump 1 LCP Grease Pump 1

Greasing Pump 2 LCP Grease Pump 2

Chute Local Panel Chute Rotate Motor Chute Tilt Motor

Chute Dismantling Panel Chute Rotate Motor Chute Tilt Motor

As well as being hardwired to the motors the Controller will use logic to prevent trying torun these motors and also stop the movement of any valves in the related system. TheBLT hoppers and associated valves have no E-stops. When the hydraulic E-stop istriggered, the BLT will complete operations in process and stop at a safe state.





3 BLT Functional Descript ion

3.1 BLT Modes of OperationThere are four modes of operation for the BLT they are; Automatic Semi-automatic Manual Local

3.1.1 Automatic Mode

Automatic mode is the only operational mode for charging the Blast Furnace. In Automode, the Bell-Less Top continuously sequences the movement of batches to thefurnace top material hoppers, and discharges material to the distribution chute per thecharging matrix.

Once in automatic the controlled and orderly starting and stopping of the charging will behandled by the charging mode Auto start, Inhibit filling, Inhibit discharging, Stop. Thesefunctions are described later.

3.1.2 BLT Semi-auto matic Mode

The purpose of Semi-automatic mode is to allow the operator to run individual BLTsequences one at a time and have the sequence stop and wait for the operator to initiatethe next sequence.

The operator selects Semi-automatic mode to:

Depressurize Material Hopper 1 (Checks to be sure the lower seal valve 1 isclosed and opens relief valve 1)

Depressurize Material Hopper 2 (Checks to be sure the lower seal valve 2 isclosed and opens relief valve 2)

Request a batch – if a hopper is available for filling (empty then the operator cansend a batch request to the Stockhouse. When the batch reaches the checkpointthe automatic sequence will run the distribution rocker and hopper valve to fill the

hopper and then wait for the next operator initiated sequence. Clear the furnace top (Sequentially empties each lock hopper per the currentcharging matrix and relieves them to atmosphere)

Clear Material Hopper 1 (Sequentially empties Material Hopper 1 per the currentcharging matrix and relieves it to atmosphere)

Clear Material Hopper 2 (Sequentially empties Material Hopper 2 per the currentcharging matrix and relieves it to atmosphere)

The distribution chute continues to rotate when the Bell Less Top is in Semi-automaticmode, and distributes material per the charging matrix, or default ring program. Ring,Sector and Point Charging are permitted in this mode.





Note : The Semi-automatic sequence must be interlocked with the stockline level limit.When the operator initiates cycling of a material hopper in Semi-automatic mode,discharge occurs only when the stockline level permissive is met. I.e. the burden mustnot be too high so the material can be discharged and not hit the end of the chute.

3.1.3 Manual ModeManual mode is a non-operational mode selected ONLY when maintenance or servicerequires shutdown of the Bell-Less Top and/or control of specific equipment or chargingpatterns such as ring charging, sector charging or point charging. Manual mode is a“supervised” mode, which means that all safety interlocks and permissives are in place.When the Bell-Less Top is in Manual mode, equipment must be operated in the proper sequence. In manual mode no batches will be requested from the Stockhouse. A batchin transit will stop at the checkpoint unless all the filling interlocks are met.

On transition to manual the BLT equipment will maintain it last state. Therefore a hopper being filled would continue to fill but the upper seal valve and distribution rocker will notclose when the batch is in the hopper. As well a discharge in progress will continueunless the operator manually uses the LMG and LSV to stop it. Note the chute willcontinue to rotate but the chute tilt will need to be controlled manually by the operator. Atthe end of the discharge the Lower Seal Valve and Material Gate will remain open andthe chute will continue to rotate, the tilt will remain in its current position.

When the Bell Less Top is in Manual mode, the operator can access manual controls for Bell Less Top equipment including:

Relief valves (open and close) Equalizing valves (open and close)

Upper and lower seal valves (open and close) Material flow gates (open, close, go to setpoint) Chute tilt motor (up or down, go to setpoint) Chute rotation motor (forward, reverse, go to setpoint) Ring Charging is permitted in this mode Point charging is permitted in this mode

It is important to note that the water, steam, nitrogen, hydraulic and lubrication systems,as well as automatic valves within these systems, operate independently of the Bell-LessTop. If the operator selects Manual mode for the Bell-Less Top, the current operationalmode for these support systems and/or automatic valves is not affected.

3.1.4 Local Mode

As with Manual mode, Local mode is a non operational mode, selected only whenmaintenance or service of Bell-Less Top valves or motors is required. Local mode isselected from a Local panel and should be confirmed via the HMI. In Local mode, abatch arriving at the checkpoint will stop the conveyor travel. Unlike Manual mode:

Local mode is “unsupervised.” Only interlock preventing simultaneous opening of LSV is enforced. The rest of the operations are allowed without concern for operational sequence or equipment state.

Local mode allows operators to dismantle the chute

Local mode allows operators to open and close the goggle valve





To switch to the Local mode a handshake sequence is followed:

1. Local request is set from Local panel (switch turned to Local or Local button islatched)

2. HMI gets indication for the Local request

3. HMI grants Local control by pushing Local button for the device or subsystem

4. Local light turns on at the Local panel indicating that Local control is active

To return control back to Remote a similar sequence is followed:

1. Remote request is set from Local panel (switch turned to Remote or Remotebutton is latched)

2. HMI gets indication for the Remote request

3. HMI accepts Remote control by pushing Manual button for the device or subsystem

4. Local light turns off at the Local panel indicating that Local control is no longer active

Note the chute has a Local Remote selector at the Chute local panel. This selector isinactive until the BLT is in Local from the control room. Therefore for the chute to be inlocal both the BLT and the LCP selector must be in local. Once in local both selectionsmust be back to remote before the chute will be taken out of local.

Note on transition to local mode the chute tilt and rotate will stop.

3.2 Charging MethodsThere are four charging methods: spiral, ring, sector and point charging. Spiral chargingis the normal method charging the furnace and is the only mode available in automatic.Ring, Sector and Point charging are only available in semi-automatic mode.

Note - using Semi-auto mode for Sector and point charging allows the equalizing andlower seal valves to operate automatically while the operator can control the materialflow gate and chute as needed.

3.2.1 Spiral Charging

In spiral charging the chute tilt follows the position pattern from the charging matrix,spending the number of revolutions requested on each position. If the matrix contains a0 then the chute transitions through that position to the next non-zero position. Thematerial flow gate position is controlled from the automatic gate control algorithm

3.2.2 Ring Charging

In ring charging the chute rotates continuously while the operator manually operateschute using chute tilt controls. The material flow gate sets its initial position from theautomatic gate control algorithm, it can also be jogged in the open or close direction bythe manual controls





3.2.3 Sector Charging

In sector charging the chute rotate oscillates between two end points select by theoperator and the chute tilt is jogged up and down or sent to a particular ring using thechute tilt manual controls. The material flow gate sets it initial program from the gate

position look-up table and can also be jogged in the open or close direction by themanual controls

3.2.4 Point Charging

In point charging the operator sets the chute rotate position, the tilt position and thematerial flow gate position using the manual controls.

3.3 Chute Angle / Ring Transit ion Methods

The ring pattern made by changing the angle of the chute can be determined by two

methods one uses time and moves the chute at the exact time the chute has made acomplete rotation, the other insures the required weight has been delivered to the ring todetermine the chute transition trigger. Since the flow is volumetric and is constant for anygiven gate setting throughout the discharge if the material flow gate setting is correctthen the two methods have virtually the identical result. The two methods differ in howdifferences between the expected flow rate and actual f low rate for a given gate settingare handled.

The only time the material flow rate is not constant for a given MFG setting is, during thegate transition to target at the start of the discharge and at the very end of dischargewhen insufficient material is present to maintain the flow.

3.3.1 Time based ring pattern

Time based ring pattern moves the chute to the next position at the point the number of rotations on that ring equals the target portions. This is the traditional way of controllingthe chute tilt drive and results in any differences in the overall material flow ratesaffecting the last ring of the pattern. i.e. If the discharge time ends 2 seconds early thenthe last ring would not have any material delivered to the last 2 seconds of the ring. Or if the discharge time was three seconds longer than expected an additional three secondsof material would be delivered to the last ring.

3.3.2 Weight based ring pattern

With a weight based ring pattern the trigger to move the chute to the next rings occurswhen the target weight for the ring is delivered. Therefore if the flow rate is higher thanexpected the weight is delivered before one full revolution and the transition to the nextring occurs before the revolution is complete. If the flow rate is lower than expected thenthe transition to the next ring will occur some time after a full revolution. The result of thismethod of chute tilt control is any error in the discharge rate is spread evenly over all therings.





3.4 Charging Progr am (Matrix)The charging program and the stockhouse weighing program are tightly related.Therefore the Charging matrix will be controlled and edited by the stockhouse. Thestockhouse will pass the BLT the entire charging matrix for display on the HMI and

charging in the event of a communications fault. The stockhouse will also send thecharging information with every batch sent to the furnace during normal operations. TheBLT and BLT HMI have no ability to edit the matrix.

The charging matrix is a maximum of 20 lines long plus a location for extra material(coke)

Since the stockhouse will control the weighing of materials and the types of materials ineach batch the BLT charging matrix screen will only show the total weights and materialtypes from the stockhouse. There will be a screen as part of the stockhouse system todisplay and edit the stockhouse material portion of the matrix. The hand shaking anddata exchange with the stockhouse is described in Section 4.1

3.4.1 Charging Matrix Fields

The header of the BLT portion of the matrix is shown below

Material Portion Discharge Time

Line TypeTargetWeight Ratio

Actualweight

11>>111<<1 11 10 9 8 7 6 5 4 3 2 1

Start Angle Target Actual

Line – Is the line number of the matrix. 0-20 line 0 is the extra material line.

Type – indicates type of material as read from the stockhouse Ore or Coke

Target Weight is the total target weight of the materials in that line of the matrix

Ratio – indicates the ratio of Pellet to Sinter

Actual Weight – indicates the actual weight that was weighed in the stockhouse. Fieldwill be blank unless material has been weighed by stockhouse. This will provide a visualindication of where the stockhouse is in the matrix

11>>1, 11<<1 – Selects the directions the portions are formed The operator can choseto discharge from the shell to the centre of the BF, or from the centre to the shell of theBF.

(Portions) - The next 11 columns are used to enter the number of portions for eachselected chute position. A 0 in the portion field will not be counted as a portion but thematerial flow gate will remain open if the chute tilt must transition through this position. If a -1 is placed in the portion field then the flow gate will close while the chute transitionsthrough that position.





Start Angle - The rotation position the discharge starts at is entered in this field (-1equals random).

Target Discharge Time – is the total number of portions in this line of the matrix *7.5seconds

Actual discharge time is the discharge time for the last time this line was discharged. Itwill time up as a discharge is in progress.

3.4.2 Portion Based Charging Matrix

The portion based charging matrix is the traditional way of selecting the ring pattern for the furnace. Using this method each portion is an equal quantity, and each ring can havezero, one or multiple portions. Only a full number of portions per ring is acceptable. Afraction of a portion per ring is not acceptable. The charging matrix defines the rings for distribution and the number of portions per ring. Using this method the material flowgate position is fixed during the discharge and the automatic flow gate correction can beused to match the target and actually discharge times with high accuracy.

3.4.3 Percentage Base ChargingPercentage base charging allows for the entry of non-integer portions in the chargingmatrix. Then by adjusting the material flow gate based on the flow curve for the gateeach ring is delivered the specified amount of material. A sample matrix is shown below.

Example Matrix - Entered as Shown

Portions TotalLine Material 11 10 9 8 7 6 5 4 3 2 1 Turns

1 Coke 1 2 2 2 2 92 Ore 3.1 2 2 2 93 Coke 1.1 2.1 2 2 74 Ore 1.1 1.9 1.9 2 7

Using non integer values for the amount on each ring provides the best visualization of what portion of the discharge is going to each ring. It also allows for adjusting a singlering’s percentage of the batch without having to reconcile the entered amount to equal100%.Note the standard logic is written to reconcile any combination of numbers that will resultin a reasonable ring pattern. Therefore percentages can also be used in the matrix Thelogic looks at the requested amounts in the matrix (percent or partial portions) anddetermines the minimum number of rotations required to meet the ring pattern and notexceed the limits of the material flow gate. If a reasonable ring pattern can not becreated then the matrix will not validate ie one ring of 98% and one of 2 % would notvalidate.

Any ring with a portion amount entered is assigned a number of turns (rotations thechute will spend on that ring). The turns as calculated as0.1 to 1.4 is gets one turn





1.5 to 2.4 gets two turns2.5 to 3.4 gets three turns etcThe reason for assigning an integer number of turns is to insure the material is spreadevenly in the ring it is assigned to.

The total number of turns must be between 5 and 15 turns for the matrix to validate.

Once the integer number of turns is calculated, the volume, weight and volumetric flowrate of the material on each ring is calculated in the Controller.The matrix is then validated by checking the flow for each ring is within the maximumand minimum permissible flow values for the Material Flow Gate.

Note all of the validations and checks used for standard discharging still apply tomatrixes entered using percentage based charging.

Once the matrix is validated and sent to the furnace top, the existing dischargealgorithms are used set the material flow gate position at the start of each ring to deliver the required material to each ring. Note charge by time or charge by weight are both stillavailable for percentage based charging.In charge by time after the chute has rotated for the correct time based on the turnsrequired for the ring (7.5, 15, 22.5…seconds) the gate will adjust for the next flowposition and the chute will tilt to the next ring position.In “charge by weight” after the correct weight is delivered to each ring the gate will adjustfor the next flow position and the chute will tilt to the next ring position.

In percent base discharging, because the flow gate is moving during the discharge thegate correction algorithm will not run at the end of each discharge.

Because the target weight for each ring varies with the size of the batch, the target andactual weight delivered to each ring will only be displayed for the batch beingdischarged.

3.5 Charging Modes

The charging modes are used to control the sequence of the charging. These controls in

conjunction with similar controls for control of the stockhouse weighing are used toshutdown the charging system in known states. Note the stockhouse controls areprogrammed by others and are not described here.

3.5.1 Auto Start Charging

The Start Charging command allows the charging system to be started after a shutdown. During the start up sequence,





If both hoppers are empty and preferred hopper is not specified in batch datathen Hopper 1 will set-up to receive a batch from the stockhouse followed byhopper 2 for the next batch.

If preferred hopper is specified and it’s available, it will receive the batch If preferred hopper is specified and it’s not available, the batch will be directed to

available hopper to avoid stopping Stockhouse conveyer If burden level is too low (BLT is in “catch-up” mode), BLT will request materialfrom Stockhouse ignoring next preferred hopper information

If burden level is not too low (BLT is not in “catch-up” mode), BLT will not requestnew batch until the next preferred hopper started discharging

If preferred hopper information is not set-up, BLT keeps track of same type of material going through every hopper. When 100 of discharges of the samematerial are done through hopper, it will skip requesting a new batch once tobreak the pattern. It is done to prevent premature wear of hopper liner caused bydischarging the same material (ore) as a result of ore-coke-ore-coke patterndischarged through two hoppers.

If there is material in a hopper(s), if the Controller determines the material hasvalid batch data then it will use this data to automatically set-up and dischargethe material in the hopper when the burden level requires it. If the Controller cannot determine the batch data then an attempt will be done to use defaultdischarge pattern for that type of material. If this is not possible an alarm will beissued and the operator will need to use semi-automatic mode to clear thehoppers of the unknown material. Note the Controller will hold the batch data for batches delivered to the top in automatic or manual. However once in manual or local the operator has the capability of adding material to a hopper or partiallydischarging a hopper or delivering unknown material to a hopper. Any of theseactions will cause the Controller to not have batch data for the material in thehopper.

Start charging interlocks

- One of MHO is in Auto or Semi-Auto mode

- Goggle valve open

- One hydraulic pump running and pressure OK

- No critical Gearbox zone grease faults present

- One Cooling pump running

3.5.2 Inhibit Furnace Top Filling

The operator can prevent the delivery of batches to the furnace top material hoppers bysetting the Inhibit Furnace Top Filling flag. This will prevent the “release next batch”signal to the stockhouse preventing any new batches from being sent to the furnace top.

Any batches currently on the belts will continue to the top. The hoppers will continue todischarge to the furnace as required by the burden level. The result will be the emptyingof both hoppers which can be useful when shutting down for maintenance.

Clearing the inhibit filling will allow the charging to continue from where it was stopped.





3.5.3 Inhibit Discharge

The operator can prevent the furnace top from discharging to the furnace by setting theInhibit Top Discharge flag. Any discharge in progress will finish but no new dischargeswill start. This can be useful following a shutdown when the operator want to watch and

manually control the timing of the discharges to the furnace as the wind is brought backon.

BLT switches into Inhibit Discharge mode if:

Greasing system switched into continuous greasing mode as a result of Chutegearbox overheating

Chute stop request was set by greasing system as a result of lubrication pointsfailure

Inhibiting the discharge with the stockhouse still running will result in both BLT hoppers

being full and ready to discharge.

Clearing the inhibit discharge will allow the charging to continue from where it wasstopped

Note if charging is inhibited for any length of time while the furnace is running, thestockline level will drop and should only be done for short periods of time.

3.5.4 Stop Charging

The operator can stop the charging system by selecting stop charging. Any discharge in

progress will finish but no new discharges will start. Any batch on the belts will continuebut no release next batches will be sent to the stockhouse.

After the charging is stopped, the auto start charging command must be used to re-startthe charge sequencing.

Note the BLT equipment can be switched from auto to semi-auto and back with outaffecting the charging mode. If the BLT is switched to manual or local the charging modewill be switched to stopped.

3.6 BLT Sequences

As described in the overview the BLT continuously sequences to receive batches fromthe stockhouse and discharge them to the furnace based on the burden level. Eachhopper has the identical sequence but they run independently therefore in normaloperation one hopper will be discharging whileThe overall sequence steps are

Relieve Prepare for material Fill Hopper Equalize Discharge





The sequence waits after equalizing (ready to discharge to furnace) and after dischargeis complete. Note once discharge is complete the hopper is able to get ready to receivematerial but for better seal life experience shows the hopper should remainingpressurized as long as possible. Therefore the relieve and prepare for material steps willstart at the point the material reaches the checkpoint P2 which is a spot on thestockhouse belt far enough back from the BLT hopers to allow the hopper to be ready for material just before it arrives.

3.6.1 Preferred Hopper and Catch-up Mode

Hopper selection for accepting new batch depends on Preferred Hopper number sentfrom Stockhouse with batch data. If no such data present, batch will be delivered to theavailable Hopper (Hopper 1 if both hoppers available). If Preferred Hopper is not ready

for filling, batch will be delivered to the other hopper to prevent stopping of theStockhouse conveyer.Preferred Hopper assignment should be done in such way that varies material typesgoing through each Material Hopper. This prevents uneven liner wear in MaterialHoppers caused by the “Coke-Ore-Coke-Ore” pattern resulting in one Hopper receivingbatches of the same material.Catch-up mode is activated if Burden level falls below discharge level plus “catch-up”limit. In this case BLT will request new batch disregarding Preferred Hopper assignmentto maximize BLT throughput.If no Preferred Hopper assignment is done in the Stockhouse, each Material Hopper

counts number of times of discharging material of the same type. If this number exceeds100, Material Hopper will skip new batch request and let the other hopper receive thenext batch. This rule does not apply in the catch-up mode.If NextHopper information is present in the Stockhouse batch data, Material Hopper willrequest the next batch at the beginning of the discharge only if its number matchesNextHopper number. This assures that Preferred Hopper assignment will be done.However, this rule is ignored in the Catch-up mode.

3.6.2 Relieve to AtmosphereTrigger

- Discharge complete in semi-automatic mode- OR Material at P1 received from stockhouse- OR requested by operator in semi-auto mode

Sequence start permissives- the primary equalizing valve is closed- the secondary equalizing valve is closed- the lower seal valve is closed

Sequence steps





- Open Relief valve- Wait for pressure to equal atmosphere

Sequence faults and alarms

Relief valve fails to open – Alarm and required operator interventionPressure time out – relief is open but pressure reading does not drop to atmospherealarm and allow sequence to complete if alarm is accepted.

3.6.3 Prepare for MaterialTrigger

- Relieve to atmosphere complete in auto mode- OR requested by operator in semi-auto mode

Sequence start permissives- the relief valve is open- the lower seal valve is closed- Hopper is empty

Sequence steps- Open Upper seal valve and close relief valve- Tare Hopper at atmosphere- Move Distribution rocker to material hopper waiting for material

- Set top fill permissive to Stockhouse

Sequence faults and alarmsRelief valve fails to close – Alarm and required operator interventionUSV fails to open – Alarm and required operator intervention.Tare Error – alarm and require operator intervention may require a semi-automaticdischarge of the hopper to remove material from hopper or mat require scale be re-calibrated.Distribution Rocker fails to reach hopper - Alarm and required operator intervention

3.6.4 Fill Hopper Trigger

- Fill hopper always follows prepare for material with no wait, but the first stepof fill hopper is to wait for the material at top signal from the

Sequence start permissives- Upper seal valve open.- Distribution Rocker at hopper - Hopper tarred empty at atmosphere





Sequence steps- Material at top received from Stockhouse- Check for wait stable- Compare hopper weight to weight sent from stockhouse- Move Distribution rocker to centre- Close USV


Filling too long – Alarm and required operator interventionWeight Compare Error – alarm and require operator intervention accepting fault willallow sequence to continue.USV fails to close – Alarm and required operator intervention.Distribution Rocker fails to reach centre position - Alarm sequence continues butoperator must correct before next hopper can receive material.

3.6.5 Equalize (Pressurize Hopper)Trigger

- In auto Equalize always follows Fill hopper with no wait, the USV closes theequalize step will begin

- Or in semi auto the hopper will equalize is trigger by the operator

Sequence start permissives

- Upper seal valve closed.- Lower seal valve closed

Sequence steps- Open primary equalizing valve- Pressure in Hopper within 0.15 bar of furnace pressure- Close PEV (so SEVs can control pressure- Check pressure compensated wait. (Weight before pressurization should

equal weight after pressurizing.- Regulate hopper pressure to 0.15 bar above furnace pressure


Hopper fails to reach furnace pressure – Alarm and require operator interventionWeight Compare Error – alarm and require operator intervention; accepting fault willallow sequence to continue.SEV fault – – alarm and require operator intervention; accepting fault will allow sequenceto continue.





3.6.6 Discharge Hopper

Trigger - Furnace burden level as measured by the Stockrod has reached the

discharge levelSequence start permissives- hopper pressurised- stockline level gauge in parked position- goggle valve open- Other lower seal valve closed

Sequence steps- Open lower seal valve- Switch SEV-PCV from pressure regulator to flow regulator. Nitrogen volume

into hopper equals material flow out of hopper - Open Material flow gate to target position- Wait for empty signals (as determined by sonic sensor and weigh scale)- Fully open material Flow Gate- Close Material Flow gate.- Close Lower Seal valve- Close SEVs


Lower seal valve Failed to Open - Alarm and require operator intervention; the other Hopper may dischargeMaterial flow gate failed to open - Alarm and require operator intervention; the other Hopper may discharge (Lower Seal valve will need to be closed manually)Hopper failed to empty (bridge detection – no flow present with material weightremaining in Hopper) - Alarm and require operator interventionMaterial Flow gate failed to close - Alarm and require operator interventionLower seal valve failed to c lose - Alarm and require operator interventionSEV failed to close - Alarm and require operator intervention





3.6.7 Chute Tilt and Material Flow Gate during DischargeThe following flow chart shows the Material flow gate and chute tilting control during thedischarge.

Calculate Discharge time(Total Portions * rotation Time = Discharge time)

Calculate Flow rate required(Batch Volume / Discharge time= Flow rate)

Calculate and Move MFG Opening based onrequired Flow rate and material type

Weight or time based?

Calculate Weight delivered to each RingCalculate Time on each Ring

Calculate Flow rate during discharge

Targetweight

reached

TargetTime

reached

Chute tilt to next ring based on matrix

Store weight on ringStore time on ring

Hopper Empty?

Discharge complete

Update material flow gate model

PercentageCharging

Gate

move duringdischarge?

Discharge

Time withintolerance

End

No

Start of Discharge

Yes

YesYes

TimeWeight

No

NoNo

Yes

YesYes

No No





3.7 Detailed Device Operation and InterlocksNote interlocks marked with a (*) are hardwired. They are bypassed if Local mode isselected. The interlocks with the upper seal valve, lower seal valve and relief valve canbe by-passed by a software function key (password protected) provided BF top pressure

has been reduced below 0.15 bar. These Interlocks are marked (**).

In the local control (maintenance) mode no hardwired interlocks are provided betweenthe gates. Extreme caution in local cont rol mode is a must!

The BLT devices have the same mode as the BLT subsystem they belong to and haveall the modes the BLT has (see BLT modes). Therefore for clarity only exceptions,restrictions or special cases of the modes are described in the device detaileddescriptions

3.7.1 Distribut ion rocker The distribution rocker moves to direct the material from the stockhouse conveyor to oneof the lock hoppers. When the lock hoppers are not receiving material the DR moves tothe centre position. This is to prevent small amounts of stray material that may arrivefrom the stockhouse conveyor from falling on the closed upper seal valves.The distribution rocker is controlled by a bi-stable hydraulic valve. The valve moves inthe direction commanded by the Controller and stops when both the Controller outputsto the valve are off.Both outputs for DR can never be on at the same time.When driving the DR to a hopper the output for that direction remains on even after thelimit switch is made.The distribution rocker uses 4 limit switches to indicate the position of the valve.

The following table shows the DR rocker position limit switch arrangementSwitch

DR Position A B C D At Hopper 1 On On Off Off Between Hopper 1 and Centre

Off On Off Off

At Centre Off On On Off

Between Hopper 2 and Centre

Off Off On Off

At hopper 2 Off Off On On

The distribution rocker can move to the hopper 1 IF:

- The upper seal valve of the hopper 1 is opened.

The distribution rocker can move to the hopper 2 IF:





- The upper seal valve of the hopper 2 is opened.

The distribution rocker can move to the middle position IF:

- There is no material flow from the conveyor belt (batch at top detected andshort time delay).

3.7.2 Upper seal valveThe upper seal opens to receive material from the stockhouse. It is controlled by a bi-stable hydraulic valve. There are individual open and closed outputs, when an output ison the USV moves towards the direction of the output. When both outputs are off theUSV stays in its last position. When the USV is requested to open or close the requiredoutput stays on even after the open or closed limit switch is made. This ensures the fullhydraulic pressure is available to hold the valve in the correct position.

The upper seal valve can close IF:

- Hopper not overfilled as calculated by weighing equipment and material type.Hoper overfill level switch not made

- material hopper overfill level switch is clear - Distribution Rocker High level switch is clear - The distribution rocker is in the middle position or directed to the other

hopper -

The upper seal valve can be opened IF:

- the primary equalizing valve is closed (*)- the secondary equalizing SEV-SV valve is closed (*)- the lower seal valve is closed (**)- the relief valve is opened AND atmospheric pressure is reached (pressure

transmitter OR time delay (5s) + alarm + alarm reset





3.7.3 Lower seal valveThe lower seal opens to discharge material to the furnace. It is controlled by a bi-stablehydraulic valve. There are individual open and closed outputs, when an output is on theLSV moves towards the direction of the output. When both outputs are off the LSV staysin its last position. When the LSV is requested to open or close the required output stayson even after the open or closed limit switch is made. This ensures the full hydraulicpressure is available to hold the valve in the correct position.Both the open and close outputs can never be on at the same time.The two lower seal valves will mechanically interfere with each other therefore the other lower seal valve being closed is a hardwired interlock with no by-pass.

The lower seal valve can open IF:

- The goggle valve is open- The opposite lower seal valve is Closed (*)- the upper seal valve is closed (**)- the relief valve is closed (**)- the BF pressure is reached (differential pressure transmitter OR- time delay (5s) after equalizing valve is open + alarm + alarm reset OR

interlock bypassed and furnace pressure below 0.15 bar - max charging level not reached

The lower seal valve can close IF:

- The material flow control gate is closed

3.7.4 Relief valveThe relief valve is used to relieve the pressure in the hopper to atmosphere. It iscontrolled by a single mono-stable hydraulic valve with spring return to close the RV.When required to open, the open command remains on even after the open limit isreached. When the power to the open output is removed the RV will close.Note during the normal sequence the relief closes as the USV opens this prevents dirtfrom the material filling hopper entering the relief valve.

The relief valve can open IF:

- the primary equalizing valve is closed (*)- the secondary equalizing valve is closed- the lower seal valve is closed (*)

The relief valve can close IF:





- There are no interlocks provided.

3.7.5 Primary equalizing valveThe primary equalizing valve is used to pressurize in the hopper to near the furnacepressure. It uses Semi-clean gas which is at a slightly lower pressure than the furnace.Once the pressure is close to the furnace pressure nitrogen is used to bring the hopper to above furnace pressure (see Secondary Equalizing Valves)The PEV is controlled by a single mono-stable hydraulic valve with spring return to closethe PEV. When required to open, the open command remains on even after the openlimit is reached. When the power to the open output is removed the PEV will close.

The primary equalizing valve can open IF:

- the relief valve is closed (*)

- the upper seal valve is closed (*)- the secondary equalizing valve is closed- opposite hoppers primary equalizing valve is closed

The primary equalizing valve can close IF:- There are no interlocks provided.

3.7.6 Secondary equalizing valvesThe secondary equalizing system consists of two valves a solenoid operated shut-off valve (SV) and a pressure/flow control valve (PCV) to regulate the pressure in the

hopper.The SEV-SV opens when ever secondary equalizing is required. The SEV-SV iscontrolled by a single mono-stable hydraulic valve with spring return to close the SEV-SV. When required to open, the open command remains on even after the open limit isreached. When the power to the open output is removed the SEV-SV will close.

The SEV-PCV has two modes of operation- During the equalize step of the BLT sequence the SEV-PCV regulates the

hopper pressure to just above the furnace pressure (0.1 Bar).- During the discharge step the valve regulates the volumetric nitrogen flow to

be equal to the volumetric flow of material out of the hopper. This helps toprevent dirty blast furnace gas from entering the hopper helping to extendthe valve seal life

The secondary equalizing valves can open IF:

- the relief valve is closed- the upper seal valve is closed (*)- the primary equalizing valve is closed- hopper is not more than 0.1 bar above furnace pressure





The secondary equalizing valves can close IF:- There are no interlocks provided.

3.7.7 Material flow gateThe material flow gate is used to regulate the volumetric flow of material to the furnace.

The flow is regulated so that the discharge duration is equal to the time required tocomplete the selected ring pattern.The material flow control gate position is controlled by a hydraulic proportional valve, two(2) encoders and fully open and fully closed limit switches.

The maximum opening speed is 15°/sec and the gate is controlled via a proportionalhydraulic valve. The material flow control gate positioning accuracy is ± 0.1°. A PID

control loop has to be provided in the Controller to positioning the gate.

The opening of the material flow control gate in automatic and semi-automatic chargingis calculated and carried out automatically to the required opening. As the hopper "empty" signal is reached, (weight and/or sonic detector), the gate will be openedcompletely before it can be closed again.On manual (point and sector charging), the gate moves to the opening position selectedon the HMI as soon as the open order is activated, while in local control mode, the gatemoves only as long as the push-button on the local control box is pressed (nopositioning) and can be stopped at any position.

In local control mode, the opening speed is given by the Controller set points.

In manual and automatic control mode the opening and closing speed set point is set bythe Controller and will be selected according to the position control loop.

There are no interlocks provided in local control mode, except for proximity switches atfinal position.

The material flow control gate can be closed during discharge if selected accordingly.

Centre coke charging is a case where he MFG closes during the discharge. In this caseno complete opening before closing is required.

The material flow control gate can open IF:

- the lower seal valve is opened- Max charging level not reached

The material flow control gate can close IF:





- There are no interlocks on closing the material flow gate

3.7.8 Chute Tilting Drive

The chute tilting movement is divided into 11 positions where the position 11 is the mostouter position and position 1 is the most central position of the BF.

The definition of these 11 positions is based on the falling curves of the material from thechute. During the filling of the BF, these values may be checked and corrected if necessary. There are separate ring angle tables for each major material group (up tofive materials)

As the BF will not always be operated at the same charging level, sets of ring positionsfor different real charging levels are required. For this purpose 3sets of degree values

will be stored in the Controller. The chute tilt will position the chute based and when thecharging level is below fixed limits, the second or third set of values will be usedautomatically (if selected) by the Controller. This allows having a good materialdistribution in the case of a slip of the charge without need to change the chargingprogram (matrix) by the operator.

The ring angle tables are stored in the Controller and can be changed via HMI byauthorized person.

For the position control of the chute, two absolute position encoders (one operating and

one stand-by) are fitted on the tilting drive gearbox.

Dynamic braking will be provided on the VVVF controller to allow an accurate and quickstopping of the chute. The mechanical brake will only be closed after the chute tilt motionis stopped.

The tilting of the chute is limited by 3 limit switches installed on the planetary gearbox- 1 degree lower end of travel- 52 degrees upper end of travel when not in dismantling position- 77 degree upper end of travel when in dismantling position.

-Note the above 52 degree limit also blocks the chute rotation.

To be able to dismantle the chute, it must be moved higher than 52°. This can only bedone in the local control mode. First the chute must be positioned in front of thedismantling door (contact from the limit switch on the rotation gearbox shaft; then thetilting movement must be mechanically unlocked. After this has been done, the upper 52° limit has to be unlocked (by-passed) by the dismantling selector switch on the localcontrol box.





Now it is possible to move the chute upwards to the upper limits 77° with the pushbuttons provided on the local control box.

Note the 52 degree limit does not cause an alarm when dismantling is selected.

The safety interlocks (end of travel limit switches) are hard wired. The 52 degree limit isby-passed by the “at dismantling position” limit from the chute rotate. If an end of travellimit is reached then the chute must be placed in local and the pushbutton to move thechute away from the limit used to clear the end of travel fault.

3.7.8.1 Chute greasing

Every 100 discharges the chute must be greased this is accomplished by energizing agrease piston solenoid for one complete revolution of chute rotate which will push the

plunger for grease as the chute rotates past the grease piston. A pressure switchconfirms the grease piston was pressurized.The operator can also activate greasing cycle by triggering the “Go Grease” commandon the chute control faceplate in the HMI.

3.7.9 Chute Rotation DriveThe position of the chute is given by two encoders (one operating and one stand-by) andone limit switch. The encoder is provided for initiating the material discharge into thefurnace and for sector charging (low speed only is used for sector charging). The limitswitch provided for the chute dismantling position must be active if the chute tilting

movement has to go higher than 52°.

The encoder will be used in automatic mode to define the start of each hopper dischargeSection 3.4.1 and to record when each ring is complete.

Normally the chute rotation will not be stopped in the automatic control mode (to reducemechanical stress on the gearbox) and is rotating at high speed (1 revolution = 7.5seconds). However, if the upper limit of chute tilting angle (52°) is reached, the chuterotation will be stopped and an alarm will be given. The chute rotation direction (left or right) can be selected and will be alternated based on the number of charges dumped into the furnace, in order to guarantee an equal wear of the chute. Since the chute rotationdrive is equipped with a VVVF controller, an accurate positioning of the chute is possibleas the chute rotation speed can be well controlled. Considering the importance of therotation drive for a good operation of the BF, two (2) VVVF drives are installed whereone is in operation and the second is as stand-by unit. The chute rotation direction canonly be changed between two material discharges.

The electro-mechanical brake should only be closed after the chute has come to acomplete stop as indicated by the VVVF (The electro-mechanical break is not used tostop the chute but only to hold the chute in position).





When the direction of rotation requires changing, the direction change will follow thedeceleration and acceleration ramps set on the frequency converter.

Beside the normal standard motor protections, thermistor sensors (thermo-resistancesensors) are provided in the motor winding. The safety interlocks (52 degree chute tiltlimit switch and dismantling selector) are hardwired.

The moving speed of the rotation is approx. 48°/s (8 rpm). A dynamic braking will be pro-vided on the VVVF controller to allow a controlled stopping of the chute.

3.7.10 Goggle valve

The goggle valve can only be opened and closed in local mode.The goggle valve is hydraulically operated with motorized valve for moving the plate andsolenoid valve for unclamping. The normal operating steps are to unclamp the valve andthen swing it to the required position and then clamp the valve.The moving commands are de-energized when the destination open or closed isreached. The open and close outputs can not be energized at the same time.

The goggle valve can open IF:

- the goggle valve is unclamped

The goggle valve can close IF:

- the goggle valve is unclamped

The goggle valve can be clamped IF:

- the goggle valve is in open or closed position

The goggle valve can be unclamped IF:

- BF pressure is below 0, 05 bar.

3.8 Control LoopsThe BLT makes use of several complex control loops to assist in charging the furnace

3.8.1 Sonic Flow detectorsEach Weigh hopper is equipped with a sonic flow detector. This is an analog device thatmeasure the amplitude of the vibration created by the material flowing through the

discharge throat of the hopper. The amplitude varies by material and therefore a





threshold is set in the Controller for each major type of material. Flow is considered to bepresent when the amplitude of the signal from the sensor goes above the threshold andis considered to not be present when the amplitude is below the threshold.When using the sonic sensors to determine the end of the discharge, flow must first beestablished (threshold met) at the start of the discharge, before the lack of a signal isused to indicate an empty condition. If flow is not established an alarm is generated.(see 3.8.2.6 Discharge Monitoring for a full list of sonic vs scale conditions and their effect)

3.8.2 Weighing Equipment

3.8.2.1 Pressure compensat ion

Each hopper has a weighing system used to determine the amount of material in thehopper and control the discharge. Because the Hoppers are subjected to the furnace

pressure from the bottom, the lifting affect of the pressure on the bellows must becompensated. Since the flexibility of the bellows is also affected by age andtemperature, additional factors are needed to have an accurate and complete pressurecompensated weight.

There are two pressure sensors at the bottom of each Material Hopper (PT-5511A and Bfor Hopper1 and PT-5521A and B for Hopper 2). One of the sensors reading is used for pressure compensated weight calculation and the other is selected as spare(assignment made through HMI). If the pressure sensors reading differ for more than 0.1bar, an alarm is issued.

As well as the pressure and temperature affects the overall dead weight of the hoppersdecrease with time due to the wearing of the liners. The weighing system algorithmaccounts for all the factors affecting the weight.To provide accurate weighing the scale will have Profibus network connection to the BLTController I/O. Full details of weighing equipment are listed in Section 2.3.4.1

The following shows the weighing parameters





Max. Scale Weight - is used to set the scaling of the input if required. If a networkconnect to the scale is available then this will be for information only.

Weight Adjust Factor – compensates for difference between batch weight sent by theStockhouse and received batch weight measured by BLT (K1 = W STK/WT1)Hopper Dead Weight – the weight of the empty hopper used to calculate the raw netweight of the hopper (Raw net weight = Raw gross weight – dead weight). This isneeded if the scale can not send a negative weight to the Controller. If the scale weightoutput is set to zero when the hopper is empty and at atmosphere then the raw emptyweight of the pressurized hopper will be a negative value.No motion time – Time used to determine the scale weight has stabilized before doingtriggered weigh compensation factor calculations.Relieved tare weight – is the amount the hopper weight has changed from its deadweight when measure empty and at atmosphere. Note this value can be positive (due tobuild up of material) or negative ( due to wearing of the hopper)and is limited a maximumamount. If the maximum tare amount is reached an alarm is issued, and Hopper Deadweight needs to be changed to bring the Tare weight to zero.

Equalized Tare value - corrected remaining Hopper weight at the end of previousdischarge when Hopper became empty. Should not exceed adjustable threshold (± 500kg min, ± 1500 kg max); otherwise an alarm is triggered and pressure compensationsystem needs to be checked.





Relieved Difference value – difference between batch weight sent by the Stockhouseand compensated batch weight measured after filling the Hopper before pressurizing.Should not exceed adjustable threshold (± 500 kg min, ± 1500 kg max); otherwise analarm is triggered and pressure compensation system needs to be checked.Equalized Difference value – difference between compensated Hopper weight beforeequalizing and after equalizing. Should not exceed adjustable threshold (± 500 kg min, ±1500 kg max); otherwise an alarm is triggered and pressure compensation systemneeds to be checked.Compensator Diameter – is the affective diameter that the hopper pressure lifts againstCompensator area – is the area the lifting force acts onCurrent hopper pressure – hopper pressure as read from the pressure transmitter Lifting Force (Newtons ) – Force created by the hopper pressure on the compensationareaCompensation adjustment factor – coefficient for fine-tuning of the lifting forcecomponent of the pressure compensation system. Should be 1 at the start-up.Lifting Force (kg) – lifting force adjusted for use in the weighing calculationHopper raw weight – raw weight read from the scalePressure compensated weight - is the result of all the weighing factors = lifting Force +(Hopper raw weight – dead weight)* weight adjustment factor

3.8.2.2 Tare (hopper empt y)

As soon as the discharge is finished and before the hopper can be refilled, the hopper should be tarred. The tarring order will be given when the upper seal valve is open and

the Hopper is at atmospheric pressure. Now the stored dead weight of the hopper ischecked with the actual measured weight.

If the difference is not bigger than a preset value (+ 1 t), the net weight will be reset to 0(the stored dead weight will not be changed).Now the sequence can continue and the batch will continue up to the top.

If the difference is too big (> 1 t) an alarm will be given and the sequence will be stopped(Conveyor belt point 2). The stored dead weight as well as the allowed difference canonly be changed by authorised personnel (password protected).

3.8.2.3 Filling finished

As soon as the batch has been filled into the hopper, a signal (time delayed) "fillingfinished" (end of batch) is given and the zero flow rate signal will be waited for. If the flowrate is zero, the net weight will be stored and compared to the expected weight from thestock house.





If the difference is not bigger than + 1 t the sequence can continue with the closing of theupper seal valve. If the difference is bigger the sequence will be stopped and an alarmwill be issued.

3.8.2.4 Full - Overfull

Hopper overfill is based on the volume of the material. Since only material weight ismonitored, the weight threshold levels of each type of material are used in addition toHigh Level limit switch in each Material Hopper to calculate the overfill condition for thatmaterial. This overfill weight is compared to the hopper net weight to detect and alarmthe hopper over fill condition.The High level thresholds for each type of material should be selected at a level allowingclosing USV without interfering with material.If the High level is reached, the Stockhouse belt will be stopped and operator will begiven a warning. Operator can chose to discharge received material in semi-auto modeor to bypass the warning and continue filling.If the High-High level (stored value) is reached or High Level limit switch is triggered, theclosing of the upper seal valves will be blocked. An alarm will be given. The chargingconveyor belt must be stopped. In this case, manual action of the operator is required toempty the hopper into the BF (Select manual operation mode, reduce BF pressurebelow 0.15 bar, open lower seal valve, open material gate and discharge material intothe furnace).

3.8.2.5 Empty signal

The hopper empty signal uses the weigh scale compensated weight and the sonic flowdetectors to set the hopper empty signal.Hoper empty equals

- Scale weight below empty threshold- Scale flow rate returns to zero- Sonic flow stops (sonic flow must be seen before Sonic can be used for

empty detection)

The hopper empty signal is used to finish the normal discharge cycle and performcorrection for material flow gate set point calculations





3.8.2.6 Di scharge Moni toring

The weigh scale and sonic detectors are used to monitor for several material flow and/or sensor faults. These are described in the following table

ConditionScale SonicShows Flow No flow The sonic sensor does not register material

flow but the scale is showing a flow out of thehopper - it indicates the sonic sensor hasfailed. Alarm and finish discharge using scalesignal.

Shows no flow but notempty

shows flow Un-determined fault could be scale fault or could be sonic picking up. Alarm and finish

discharge using sonic sensor.Flow was establishedand then no flowshows and empty

shows flow Sonic detector is Faulted. Alarm and allowdischarge to end

Scale shows no flowand not empty andflow never wasestablished

Sonic matchesshowing no flow andflow not established

Material has bridged or some other failure hascaused material to not be discharging from thehopper. Alarm and request operator intervention

Flow was establishedand then lost buthopper not empty

flow established andstopped

Material has bridged or some other failure hascaused material to not be discharging from thehopper. Alarm and request operator

interventionScale show materialpresent and Materialdischarge timed out

If the maximum discharge time is exceededalarm the operator. Most likely it is due to andundetermined weighing fault but operator mustintervene to correct. Discharge does not endwithout operator intervention.

3.8.3 Material Flow Gate Algorith m

In order to distribute the material in the portions as requested by the ring pattern, the

material flow must have its setpoint determined based on the amount of and type of material being delivered to the furnace.

Based on the volume of material in the hopper and desired discharge time the requiredvolumetric flow is calculated. Then the required flow gate position to obtain the correctvolumetric flow is calculated using the gate model for that material type. When thedischarge is complete the gate positioning model is updated based on the actual flow.To stabilize the model and not react to flow changes likely not from the gate onlydischarges with 20% of the target time are used to update the model.





The model uses the last several discharges through the hopper of a particular material(5 material types can be set) to calculate the volumetric flow rate vs gate position for thatmaterial.

The charge by time or charge by weight selection is independent of the material flow

gate correction algorithm. The MFG correction algorithm makes use of the followingcharacteristics of solid material flow through the gate.

The material flow gate controls the volumetric flow which in turn is proportional tothe mass flow when an accurate density value is known for the material. Whenmaterials are mixed the average density can be used or the density and weightsof each individual material can be used to calculate the total volume.

The volumetric flow rate for a given gate setting will differ depending on materialcharacteristics. Coke, Pellets and Sinter flow differently due to the different partialsize and shape. Different types of coke may also flow at different rates. Thereforeseparate correction coefficients are used for each major type of material

The flow through the gate is not dependent on the level in the hopper. Thematerial is solid and therefore flows similar to sand in an hour glass. The materialis not a liquid and the concept of head pressure is not valid in this case.

The algorithm requires the following information to function properly.

Accurate weight of material in the hopper. When tracking or stockhouseinformation is not available the weight from the hopper scales can be used.

Accurate density information for the material in the hopper. This must come fromthe stockhouse

Accurate material types for the materials in the hopper. This must come from the

stockhouse or the recipe system. A reasonable sample length of flow rate vs position is required to provide stable

control. Sampling every half revolution does not provide a stable control of material flow gate. Sampling at a slower rate might provide stable control if theflow during the time the gate is moving is ignored. Therefore at this time if thematerial flow gate is moved during the discharge then the flow gate setting modelis not updated.

3.8.4 Centre coke charging

Centre coke charging closes the material flow gate for rings with a -1 in the ring pattern.

The intent of this feature is to allow the gate to close after distributing most of a batch of coke from the furnace wall inward and then closing the gate and transitioning to centre of the furnace and re-opening at the desired ring to place the remaining batch in the centrerings.

It is not recommended for transitions through a single ring as the MFG opening andclosing time will be slower than the chute transition time though the ring. Therefore thegate will only partially close and then stop and re-open when the chute tilt is complete.

Centre Coke charging has the affect of extending the discharge time for the batch by thetime it takes the chute to transition through the closed rings.





The material flow gate model does not update during centre coke charging.

3.9 BLT HMI Screens

The BLT portion of the HMI will contain the following main screens there will be a

Bell-less Top Overview Bell-less Top Detail Screen Charging Matrix Screens Interlock Screen(s) Chute Angle Table Material Flow Gate Correction Trend screens

The screens and their functions are described below

In addition to the main screens various pop-ups will be used as required to provide the

individual control and mode selections of the various components.

The screens samples shown below are intended to show screen content and layout theyhave not been generated using the ABB 800xA software. This will be completed oncethis functional specification is approved. The approved screens will be generated asclosely as possible using the ABB software. A working simulation of the BLT and theHMI system is available for review. The simulation can be viewed any where in the worldusing web meeting software and a conference call.

3.9.1 Bell-less Top Overview

The Bell-less Top overview screen provides an overview of the current state of the BLT.It has limited operator controls and is intended to provide a good overview of the overallstate of the BLT. It will include the following;

The status of the stockhouse conveyor that feeds the BLT as well as thecheckpoint and batch on top signals

the current position of the hopper valves, and distribution chute the current hopper pressure, weight and high level switch the chute rotation speed direction and position the chute tilt position, by angle and position number the auto, manual, local mode indication and whether any alarms are present for

each auxiliary subsystem; grease, hydraulic, cooling water, steam heating current sequence step of each hopper equalizing relieving, ready for material,

discharging etc. A summary of the last discharge position distribution actual amounts The next two lines of the discharge matrix position pattern and material based on

information received from the stockhouse Controller Top temperature and pressure Stockline level





3.9.2 Bell-less Top Detail Screen

This screen provides furnace top controls and operational details of each item

The screen is categorized as follows:Material Hopper1 (Left of screen)Material Hopper2 (Right of screen)Blast Furnace and Chute (Bottom of screen)

Current Batch data

with current ringhighlighted

Tracking data for

batches in hoppers

Chute Tilt and

Rotate Position





Material Hoppers Details

The following material hopper controls are provided with status indication:

Relief Valve (Open / Close) Primary Equalizing Valve (Open / Close) Secondary Equalizing Valve Shutoff Valve (Open / Close) Secondary Equalizing Valve Control Valve (Jog Open / Jog Close) Secondary Equalization Properties (Transmitter selection)

Upper Seal Valve (Open / Close) Lower Seal Valve (Open / Close) Material Flow Gate (Jog Open / Jog Close) Material Flow Gate Properties (Transmitter selection) Hopper Selection 1 only, 1+2(both) or 2 only

The following material hopper details are provided:

Hopper Weight (lbs.) and Status

Blast Furnace Details

Blast furnace controls and details are provided:

Hopper

sequence status

Equalizing and

Relieve

Semi-Automatic

Controls

Mode Indication

and selection





Chute Rotation Chute Tilt Stock lines Charge Method Selection Furnace Mode Selection

Semi Automatic Mode Sequence Controls

Chute Rotation:

The following chute rotation controls are provided through the chute rotation Pop-up:

Status (position, direction and speed of rotation Mode selection (auto manual local) Manual controls VVFD status and selection Position transmitter status and selection Alarm conditions(separate tab) Interlocks conditions (separate tab) Maintenance information (separate tab)

The following chute rotation details are provided:

Motor Current (Amps) Chute Position ( ° )

Chute Tilt:

The following chute tilt controls are provided:

Status (position, direction and speed) Mode selection (auto manual local) Manual controls up, down or ring selection

VVFD status and selection

Chute Rotate pop-up control tab

Chute Rotate pop-up Alarm tab

Chute Rotate pop-upMaintenance tab





Position transmitter status and selection Alarm conditions(separate tab) Interlocks conditions (separate tab) Maintenance information (separate tab)

The following chute tilt details are provided:

Motor Current (Amps)Chute Position ( ° )

Furnace Top Mode Select ionThe furnace top Mode is selected from the mode selection pop-up

Auto Semi-Auto Manual Local

Semi-Auto Mode Sequence Controls

The following sequences may be controlled by selecting the Semi Auto Sequences:

Clear Furnace Top Clear Material Hopper 1 Clear Material Hopper 2 Depressurize Material Hopper 1 Depressurize Material Hopper 2

Spiral, Ring, Sector and Point Charging via Charging Mode Controls

Charging Control

The charging control Pop-up is used to Start stop and inhibit the charging

Encoder selection

DriveSelection

Encoder calibrationand Preset





Charging ModeThe Charging Mode control selects whether the chute tilt will be imitated based on Timeor Weight

Top Filling ModeThere are situations where it may be desirable to only use one hopper for charging thefurnace. The selection of Hopper 1, Hopper 2 or both is provide through this pop-up

Charging Method

A popup screen only available in Semi Automatic is provided for changing chargingproperties by selecting the Charging Method push button.

The user has the following charging options:

Spiral Charging (Charging based on recipe charge matrix) Ring Charging (Operator manually operates chute using chute tilt controls) Sector Charging (Operator selects sector range in degrees, and manually operates chute tilt)

Point Charging (Operator manually adjusts chute using chute tilt and rotationcommands)

Stockrod interface

Pop-ups will be provided for the selection and set-up of the stock rods. They will provide;

Adjustment of discharge trigger point (burden level target)

Auto manual selection of the mechanical stockrod Selection of whether the non contact stockline value is used for discharge

triggering (On/Off) Selection of which Stockrod is used to trigger discharge All, first to reach, or

individual Stockrod.

The BLT will have a static minimum stockline value that will be lower than the lowestpoint the chute reaches when vertical that will be used as an interlock to the lower sealvalve and will be the highest level the operator can set the discharge trigger point to.This will prevent the chute from hitting the burden.





Material Flow gate Pop-up

The material flow gate pop-up provides

Mode selection of flow gate (Auto Manual Local) Status Manual control Position transmitter status and selection Alarm conditions(separate tab) Interlocks conditions (separate tab) Maintenance information (separate tab)

3.9.3 Charging Matrix Screens

The charging matrix screen will provide the display and editing of the charging matrix aswell as controls for starting, stopping and inhibiting the charging sequence.

The charging matrix is a maximum of 20 lines long plus one line for extra batch.

Since the stockhouse will control the weighing of materials and the types of materials ineach batch the BLT charging matrix screen will only show the total weights and materialtypes from the stockhouse. There will be a screen as part of the stockhouse system todisplay and edit the stockhouse material portion of the matrix. The hand shaking anddata exchange with the stockhouse is described in Section 4.1.

Operator choosestrigger method





3.9.4 Chute Angle Screen

The chute angle screen provides the list of the chute angles for each position 1 to 11 for each material. These are read only values.

There are a total of 11 sets of position angles for the chute. There is a set of 3 values,based on burden level for each type of material Coke, Pellets, Sinter and Other. If pelletsand sinter are mixed then position angle table of the material that is the larger portion of the batch is used i.e. if the mix is 60% sinter then the sinter position angle tables is used.“Other” will only be used if required by the material mix for a specific condition nothandled by the coke, pellet or sinter selections.

Material type Target Weight Ring patternHighlighted Linenumber for batch inhopper





3.9.5 Device Faceplates (pop-ups)For each type of device on the furnace a pop-up is provide for control, status, interlockand alarm information.The pop-up share a common look with tabs to select the

- Control faceplate,- Interlock faceplate- Alarm faceplate- Maintenance faceplate- Trend faceplate (where applicable)

The control faceplate allows the operator - Mode selection (auto manual local)- Manual control (open close start stop)- Status (position, running, stopped etc.)

The interlock faceplate shows the interlocks for running, opening or closing the deviceand which ones are active.The alarm faceplate shows any alarms related to the deviceThe maintenance tab shows maintenance information about a device such as;

- Usage timers or counter - Set-up information such as opening and closing fault delay timers- Access to maintenance information about the device (if available)

The trend faceplateProvides a trend of the analogue values related to the device.

The following figures show a sample set of the faceplates

Analog sensors

Alarm set-up, check boxenables alarm

Trend of analog point Maintenanceselected

Trendsselected

Alarm listselected





Proportional valve

Solenoid valves

3.9.6 Trend Screens

In addition to the small trend pop-ups the HMI will have full size trend screens for

important values. The HMI will have the following BLT related trends

Tune loop fromHMI

Trends to aid withtuning

Valve timingchecks





- Furnace top and hopper pressure- Hopper weight compensated and non-compensated- Stockline values- Chute Tilt and rotate motor currents





4 Plant Interfaces

4.1 Stockhouse Interface

4.1.1 Data Locations

The philosophy for locating data, is the originating Controller will be the master of thatdata. Therefore, the stockhouse Controller will be the master of the all charging matrixdata, and the BLT Controller will execute the ring patterns for the matrix received fromthe Stockhouse.

Since the both Controllers and all the HMIs are on the same Ethernet network the HMIwill be able to display the required data from the two Controllers into one screen asrequired.

4.1.2 Data Exchange Requirements Although the stockhouse and BLT operate independently they must exchange certaindata and perform certain checks to ensure the smooth operation of the furnace.

Although the stockhouse weighs the material, a batch must fit into the material hopper atthe top of the furnace. As well the batch must be of suitable size with respect the number of portions (discharge time) so as to not be out of the normal flow range of the materialflow gate. Therefore, the stockhouse must know the constraints on discharge time for each line of the charging matrix.

The BLT doesn’t weigh the material but must know the amount of material that is beingdelivered to the top so that the material can be correctly distributed to the furnace in theallotted discharge time. This will also make it possible to check that the weight of material received by the material hopper matches the weight of material sent by thestockhouse.

The following sections of this spec will provide the details of the data to be exchanged tomeet these requirements.

4.1.3 Data definitions

There are three types of data needed by the Controllers

Constants and static data defining the physical limitations of the system. The charging matrix data for the current active charging matrix The dynamic data for the current lines of the charging matrix being executed The timing and interlock signals that allow the smooth delivery of batches to the

Blast Furnace.

4.1.4 Common Data

This is data that is constant and can be held by both Controllers and does not need to beexchanged





Description Value

Maximum Number of Lines in the Matrix 20 + 1 extra

Working volume of lock hopper 80 m 3

Material Flow Gate minimum flow rate 0.2 m 3/s

Material Flow Gate maximum flow rate Coke 0.8 m 3/s

Material Flow Gate maximum flow rate Pellets or Sinter 0.8 m 3/s

Time for one portion** 7.5 s

** Portion time is based on 8 RPM chute rotation speed.

4.1.5 Charging Matrix Data Exchange

The following data will be sent for only the active charging matrix.

Each line of the matrix will consist of the data type BATCH_RESULT. There will be anarray of 21 BATCH_RESULT lines which make up the entire matrix.

The matrix tag will be called MATRIX_from_PCN_04 in the BLT Controller. Line 0 (zero)is reserved for the EXTRA COKE batch.

From Stockhouse to the BLT

Field Description Range Type Units

Lines Number of Lines inMatrix

0 to 20 (20 + 1) Integer

Line Data – BATCH_RESULT

Number Unique Batch Number DoubleInteger

Line_Num Matrix Line Number 0 – 20 Integer

Material Material types:1. Coke2. Ore

Number of Material typescan be extended to up to

five

1 - 5 Integer

Weight Target weight of material 0-100000 DoubleInteger

Kg

Volume Volume of material 0 – 80 m 3 Real m 3

BLT_info BLT Charging Information * See Below BATCH_BLT

BLT Charging Information





RingNr Number of Rings ateach position

Rings 1 to 11

0 to minimum flowvalue

INT[12]

Start_Angle Rotation Start Angle -1 to 359 (-1 indicatesrandom) INT Degrees

Direction Discharge patterndirection (-1 = OUT toIN, 1 = IN to OUT)

-1 OR 1 INT

Notes:

1) The table contains entries for all 21 possible lines of the matrix (x=0 to 20,where 0 is the extra line)

4.1.6 Charging Matrix Validation

Whenever a line of the charging matrix is edited it must be checked that it meets thefollowing criteria. Also, if any moisture or weigh error correction is applied by thestockhouse in real time then the amount of correction should be limited to stay within thecriteria.

Criteria Checked by ResultTotal Volume of a Batchmust not exceed capacity of the material hopper (80m 3)

Stockhouse Alarm and prevent Acceptance of Line Edit

Volume of a batch dividedby target discharge timemust be within material flowgate limits

Stockhouse Alarm (Edit can beaccepted but if the flow rateis too low, the discharge willrun at the minimum rateand the discharge will endearly. If the flow rate is toohigh, the discharge time willbe doubled and the top willspend two revolutions per portion one each ringinstead of one)

Stockhouse limitations- thestockhouse Controller should also check that thematrixes meet all thelimitations of thestockhouse. Since thestockhouse is not in PW’s

scope these checks are not

Stockhouse





defined in this document

Any recipes downloaded from a supervisory system should be valid prior todownloading, if they are not the Controllers may not allow them to become active untilthe operator corrects any validation problems.

4.1.7 Dynamic Charging Data As each batch is weighed and delivered to the furnace there will be variations in theactual values vs the target values. Therefore, as each line is delivered to the furnace theactual values must be transferred. The data should be present in these registers prior tothe Batch at Checkpoint P2 turning on.

This Dynamic Charging Data will correspond exactly to the single matrix line that isbeing charged to the furnace.

Dynamic Stockhouse data is identical to BATCH_RESULT as defined in the chargingmatrix above.

4.1.8 Batch Sequencing Signals

The following table defines the signals required to sequence the batches from thestockhouse into the material hoppers. These signals will be wired via interposing relaysto I/O points in each Controller.

Field Source Description

Conveyor run

permissive

BLTSignal turns off if high level at Material Hopper is

detected.Next_Batch BLT Turns ON at the start of the Material Hopper

discharge sequence. OR On re-start of the BLTafter stopping if a hopper is empty and there areno batches on the belts destined for that hopper

Turns Off when Batch on belt signal is receivedfrom the Stockhouse

If both hoppers are empty or will be ready toreceive a batch at the same time then the next

batch signal will be turned on again after a 30second delay after the BLT sees theBelt_on_Batch signal turn off. The stockhousewill then place the second batch on the belt after the minimum gap time (currently 80 seconds)has passed

Batch_On_Belt(Batch dischargingto belt)

Stockhouse Turns on in response to seeing Next_Batch atthe start of releasing the batch.

Remains ON while the batch is discharging tothe belt. Turns OFF when the discharge iscomplete.





Coke Stockhouse With coke batches, turns on when the trackedhead of a batch hits the logical Check Point 1located 30 seconds in advance of Check Point2. Turns off when the tail of the tracked batchpasses the logical Check Point 1 location.

Ore Stockhouse With ore batches, turns on when the trackedhead of a batch hits the logical Check Point 1located 30 seconds in advance of Check Point2. Turns off when the tail of the tracked batchpasses the logical Check Point 1 location.

Top_Ready BLT Turns ON when Upper Seal valve is open anddistribution rocker is in position to receive theBatch. If a batch is at P2 and this signal is not onthen the belt must stop immediately.

Turns OFF when End of Batch received andfurnace has started to move the distributionrocker away from the material hopper.

Batch_at_P2 Stockhouse Turns ON at the point on the belt that is just far enough back from the end that the belt can bestopped without any material discharging fromthe belt to the distribution rocker. (i.e. is thestopping distance of the belt measure back fromthe head pulley)

Turns OFF when End of Batch turns on

End_of_Batch Stockhouse Signals the tail end of the batch has reached theMaterial Hopper. Triggers the BLT to check thatthe material hopper weight has stoppedincreasing and then set-up to be ready todischarge when required by the burden level.

Turns OFF when top ready turns off.

Disch_Done

(sent on networkonly not wired)

BLT See Section 4.1.9

Turns ON when the discharge of a hopper hascompleted. Signals Level 2 system or

Stockhouse Controller to read the discharge log

Turns OFF when the Stockhouse sendsDisch_Data_Read

Disch_Data_Read Stockhouse See Section 4.1.9

Discharge Data Read Flag. Turns ON when theStockhouse has successfully read the dischargeinformation (triggered by Disch_Done) and turnsOFF when Disch_Done turns off.





CCTR


BLT See Section 4.1.9

Increments on every counter echo received fromthe Stockhouse

CCTR


Stockhouse See Section 4.1.9

Echoes the counter received from the BLT

Spare BLTStockhouse

2 spare wired Input/outputs should be wiredbetween the stockhouse and BLT Controllers

The BLT Controller will control the alternating of the hoppers and send handshakesignals to the stockhouse. This keeps the stockhouse independent of the BLT andallows the BLT to place batches on the belt in any hopper should the conditions at thetop require it.

4.1.9 Communications Monitor ing and CoordinationBoth Controllers will write five (5) DINT words to each other for the purpose of communications monitoring and trigger bits. These five words will be combined into auser defined data type containing the following items:

Field Type Description

CCTR DINT Communications Counter – BLT increments,Stockhouse Echos. Communication failuredetected when no change is seen in 1 second.

W1 DINT Trigger Bits (see below)

W2 DINT Spare

W3 DINT Spare

W4 DINT Spare

The contents of W1 trigger and clear discharge logging as indicated below.

BLT to Stockhouse

Name Bit Description

Disch_Done 0 Discharge Done Flag. Turns ON when the dischargeis done. Turns OFF when the Stockhouse sendsDisch_Data_Read

Stockhouse to BLT

Name Bit Description





Disch_Data_Read 0 Discharge Data Read Flag. Turns ON when theStockhouse has successfully read the dischargeinformation (triggered by Disch_Done) and turns OFFwhen Disch_Done turns off.

4.1.10 Inserting Extra Material

When the operator determines that the furnace conditions require the addition of anextra material (typically extra Coke), the operator can trigger the extra material line toexecute. When the extra material line is triggered the stockhouse will weigh and deliver the extra materials to the BLT. Note the stockhouse will typically have at least one cokeand one material batch weighed or weighing at any given time so these batches mayneed to be discharged to the furnace in-order to make room for the next batch.Therefore the stockhouse Controller will determine the timing of when the extra materialbatch gets delivered to the furnace. The extra material batch will be indicated by its linenumber being zero. All normal batch processing will be carried out as usual.

Note that if an extra batch is sent during a communications failure, it may be processedaccording to the default settings since there is no way for the BLT to distinguish it from anormal batch.

4.1.11 Communications B ack-up Sign als

Because the Stockhouse and BLT Controllers are communicating over a network aback-up system of Coke and Ore signals are used. These signals will only be used if acommunications failure is detected by the Controllers but are checked vs. the

communications network each batch to verify they are working correctly. If thecommunications network heartbeat is OK and the coke and ore I/O points from thestockhouse do not match the coke and ore data signals from the stockhouse an alarmwill be issued but charging will continue based on the networked signals . The electricalmaintenance staff should investigate the wired signals to determine where the problemhas occurred.

To detect communications failures two communication counters will be sent over thecommunications network. See Section 4.1.9 for details. If communication failure isdetected, then the Controllers will use the wired Coke and Ore signals to determine thematerial being delivered to the top. During a communications failure the stockhouse willweigh the material based on the charging matrix and will send a Coke or Ore signal viathe hard-wired link. The BLT will process the batch according to its last version of thecharging matrix received.

4.2 BLT Discharge Log

Once the BLT has finished discharging a material hopper to the furnace a discharge logof containing the data about how and when the material was charged to the furnace willbe created. It contains the data in the data type LogDefinition.

LogDefinition Data Type





Field Description Type Range UnitsID Identifying Data LogID

Time Time information LogTiming

MFG Material Flow Gate Data LogMFG

RingPerf Discharge Ring Performance Actual Data

RingPerformance

Data Additional Data LogInfo

LogID Data Type

Field Description Type Range UnitsBatchNo Echo of batch number for batch discharged

from BLT hopper DINT

DischNo Discharge Number (counter reset at

midnight)

INT

HopperNo Hopper number batch was discharged from(1 or 2)

INT

BatchLineNo Line number of Discharge Matrix used (-1 to20, where -1 is unknown, 0 is Extra Coke)

INT

LogTiming Data Type

Field Description Type Range UnitsStart Discharge Start Time DINT[7]

TargetDuration Target Discharge Time REAL Seconds ActualDuration Actual Discharge Time REAL

Seconds

LogMFG Data Type

Field Description Type Range UnitsMode Material Flow Gate Mode 1= Manual,

2=Timed, 3=WeightINT

Target Material Flow gate position target (0-60.0degrees)

REAL

Degrees Actual Material Flow gate position actual (0-60.0

degrees)REAL

Degrees

RingPerformance Data Type

Field Description Type Range UnitsR Array of Actual Ring Performance RingActual[13]

RingActual Data Type





Field Description Type Range UnitsPortions Number of portions discharged to Ring (0-

32767 portions)INT

ChuteAngle Chute angle for this ring (degrees) REALDegrees

Weight Weight of Material discharged to Ring (0-200000 kg)

DINT

Kg ActTime Actual time in sec that the chute discharged

in this ringREAL

Seconds ActGate Actual Gate Angle REAL

Degrees

LogInfo Data Type

Field Description Type Range UnitsChargeLevel Burden Depth at Start of Discharge REAL

Metres

FinishLevel Burden Depth at End of Discharge REAL MetresStartAngle Rotation angle at which the discharge was

startedREAL

DegreesSpiral Charge in Spiral Mode BOOL

Ring Charge in Ring Mode BOOL

Sector Charge in Sector Mode BOOL

Point Charge in Point Mode BOOL

ByTime Charge by Time Mode BOOL

ByWeight Charge by Weight Mode BOOL

4.3 Stockline Level Control System

This is based on a TMT specification for the mechanical stockline with a wired interface.TMT standard stockline uses Siemens PLCs and drives so Profibus is also possible. Thetype of stockline being used must be confirmed at by DC or TPL.

There are two types of stockline measurement devices currently used: mechanical(winches) and non-contact (radar). Totally up to three devices can be used. Their combination is used for calculating current burden level, based on operator selection.

4.3.1 Stockline Selection

The stockline level is used to trigger the start of the discharge. Since the operator hasthree possible devices to measure the burden depth, then if more than one stockline is inservice then one of the following options can be selected:

the first to reach the burden level setpoint will be used as the trigger for thedischarge

the last one to reach the burden level setpoint will be used as the trigger for thedischarge





specific Stockline will be used to trigger discharge, the other in this case will justmonitor burden level

There must always be one measuring device in auto or the hopper discharge will not betriggered. If this condition is not met then an alarm will be issued.

If more than one measuring device is in service, and their readings deviate by more than1 m (adjustable value), an alarm will be issued. It may indicate uneven burdendistribution or Stockline failure.

4.3.2 Non-contact Stockl ine (Radar)

Non-contact stockline constantly measures burden level and Controller reads it throughanalog input. The radar has a flow switch that monitors nitrogen flow through the radar body. In case of low flow, an alarm is issued.

4.3.2.1 Stockline Modes

The non-contact burden level Stockline (radar) can not be placed in manual but will havean in and out of service mode to determine whether it will be used to trigger thedischarges. When out of service it will not be used to trigger the discharge of thehoppers.

4.3.3 Mechanical Stockline

4.3.3.1 Stockline Modes

Mechanical stocklines can be in remote (Auto or Manual) or Local mode. Switchingbetween these modes is done using handshake procedure described in section 3.1.4. Inremote the BLT Controller command will control the stockline actions. In local theStockline will run based on the local pushbutton stations wired directly to the stockline aspart of the stockline control system.

Once the stockline is in Remote, the operator can use HMI to place the stockline in Auto,or Manual. In auto the stockline will be sent in and out of the furnace to measure theburden based on the charging sequence. In manual the stockline will be sent in and outof the furnace based on the operator commands via the HMI. When in manual themechanical stockrod is not used to trigger the discharges.

4.3.3.2 St ockl ine InterlocksThe stockline can not be sent into the furnace during a discharge and a discharge cannot start until the stockline is out of the furnace. Therefore the stockline lower signal canonly be sent if the both Lower Seal Valves are closed.

4.3.3.3 Interf ace Si gnals

Signals to the stockline winch

Signal Handshake Description

Remote None Signal stockline to run based on the BLT Controller





signals

Local None Stockline will run based on the local pushbuttonstations wired directly to the stockline as part of thestockline control system

Lower Stays on untilraise signalneeded or Min(-6/-24m)position signalfrom theStockline

When in remote the stockline will lower into furnaceand measure the burden. The BLT will generate thissignal if

the stockline is in use as selected by theoperator through the HMI

the discharge has finished.OR the operator has manually sent stockline into

the furnace

Raise Stays on until

Stockline parkedsignal is received

When in remote the stockline will raise out of the

furnace and go to the parking position. The BLT willgenerate this signal if

the stockline is in use as selected by theoperator through the HMI

there is a hopper ready to discharge the discharge trigger based on burden level is

reachedOR the operator manually requested the stockline

raise.

Calibrate Stays on untileither whenstockline parkedsignal is receivedor an alarmsignal is received

When in remote the stockline will do a calibrate whenthis signal is turned on. The BLT will generate thissignal

after every 150 discharges in out mode Thiswill occur during the discharge so no delay incharging will occur

OR When requested by the operator in manual

mode

Spares The standard TMT Stockrod has some spare I/O these

should be connected to the Controller.The stockline will send the BLT the following signals

Signal Handshake Description

DismantlingPosition

None Stockline is at the dismantling position

Waiting None Stockline will run based on the local pushbuttonstations wired directly to the stockline control system





Min (-6/-24m)position

Turns off onnext lower command fromBLT

Stockline went into furnace and reached the minimumposition without reaching the burden. The BLT willremember this signal and keep stockline out of thefurnace until the next discharge is completed.

On Charge None Signals the burden has been reached by the stockline

Lowering None On while stockline is lowering into furnace, turns off when On Burden

Rising None Signals stockline is rising out of the furnace

OK None Stockline is healthy and can be used for measuring

Failure None Centralised Alarm stockline can’t be used.

DB Open None Brake is Open

CalibratePosition

None The stockline is at the calibrate position

Burden LevelValue

None Is the analog value of the burden level. 4mA = 0m,20mA =24m

5 Hydraulic Functional description

5.1 Hydraulic System Overview

The Bell-Less Top hydraulic system maintains hydraulic pressure to all primary Bell-Less

Top valves (upper seal valves, equalizing valves, secondary equalizing valves, relief valves, lower seal valves, material flow gates, goggle valve, distribution rocker, planetarygearbox grease valve, and bleeder valves). Operating pressure of the system is 180-200bar.

The hydraulic system includes an oil tank with monitoring instruments; two pressurepumps, two recirculation pumps; cooling system; associated filters and manual valves;and four piston-type accumulator stands.

5.2 Hydraulic System Operating Modes

The hydraulic system’s normal mode is automatic, which is the only mode for operationof the BLT system. The hydraulic system can also be operated in Manual mode from theHMI or Local Mode from the Local Pushbutton stations.


Automatic Mode is the normal operating mode. In Automatic mode the valves andpumps will run based on the required sequences and current conditions as listed in thedescriptions below.

On transition to automatic, the system will place the valves or pumps in the correct statebased on the current system conditions.





5.2.2 Manual Mode

On transition to manual, the devices will maintain their last state. Once in manual thecontrol of the devices will be based on the Manual controls from the hydraulic HMIscreen. In Manual mode all interlocks will be active.

Operating hydraulic pump will remain in Automatic mode to provide hydraulic pressurefor BLT. If the operating pump needs to be stopped, it should be switched to standbyoperation first.

5.2.3 Local Mode

The Hydraulic Local Mode is wired through the local Pushbuttons and is available for motors only

On transition from remote to local, the devices will maintain their last state. Once in localthe control of the devices will be based on the controls on the push button stations andonly the minimal safety interlocks will be active in the control.

On transition from Local back to Remote, the system will be in manual mode.

Local control is still through the Controller.

5.3 Detailed Device Operation and Interlocks

5.3.1 Hydraulic Tank Monitoring

The hydraulic oil tank has two sections: suction and return. There is level andtemperature measuring devices in each chamber. These devices are for the interlockingand control of the hydraulic pumps and valves which are described with each device.

The following table lists the monitoring devices in the tank

5.3.2 Hydraulic Pressure Pumps

The hydraulic power supply unit is equipped with two identical pumps. One pump motor shall be designated as operating and the other as stand-by through the HMI. The stand-

LSH - 5801-AA OIL TANK HIGH LevelLSL - 5801-AB OIL TANK LOW LevelLSLL - 5801-AC Oil Tank Low Low Level - Pumps stopPS - 5801-A Return Line Filter CloggedPS - 5801-B Return Line Filter Clogged

TSH - 5801-AA OIL TANK Above 60C- EMERGENCYSTOP

TSL - 5801-ABOIL TANK Below 10C- EMERGENCYSTOP

TE - 5802 OIL TANK TEMPERATURE





by pump shall operate automatically as dictated by the system pressure requirements. If one pump is running and the pressure drops below 150 bar for more than 10 seconds alow pressure alarm is triggered and the stand-by pump is started. The stand-by pumpshall also operate automatically if the operating pump experiences a failure. TheController shall track accumulated working hours and automatically cycle the stand-bypump based on running time. One pump should always being running to supplyhydraulic pressure for the operation of the blast furnace equipment.

The hydraulic pumps have the following permissives.

Description Permissive

Hydraulic E-stop On(=OK)*

Low Low Level in oil tank On(=OK)*

Low Level in oil tank On(=OK)*

Oil Temperature Hi Hi On(=OK)*

Oil Temperature Low Low On(=OK)*

Pump Suction Valve Open On(=OK)*

No Pipe Burst in the main line On(=OK)

Pump Available from MCC On(=OK)

Pump Available from Motor Overload On(=OK)*

* hardwired,

Maintaining a reliable back-up pump is important to insuring the high availability of thehydraulic system. Therefore, one pump will be the primary operating and as such will rununless there is a fault. To keep the standby pump in good condition it will be runoccasionally for a short period of time. To accomplish this if the operating pump has run150 hours total hours since the last time the standby pump has been run then thestandby pump will be started and the operating pump stopped. The standby pump willrun for 30 minutes and then the operating pump will be restarted and the standby pumpstopped. This will have the affect of running the standby pump for 30 minutesapproximately once a week.

The time periods for Operating and Standby pumps can be adjusted through HMI byauthorized personnel. If desired, Standby pump running time can be set to zero whichwill disable automatic switching. In this case, Standby pump manual running will be

required from time to time to make sure it is in good shape.

5.3.3 Hydraulic Return Line Filter

The hydraulic return line has a dual filter with manual valves to switch the active filter.Each filter has its own pressure switch to monitor when it is time to change the filter. If the pressure switch opens, an alarm will be issued on the HMI. Since switching the filter in use will cause the switch to reset, this alarm will be latched and must be reset by theoperator through the HMI.





5.3.4 Hydraulic Circulation Pumps

The hydraulic system uses a loop to cool and filter the hydraulic oil. Two circulationpumps are used to circulate the oil through the cooling and filter circuit. One circulatingpump shall be designated as operating and the other as stand-by through the BLT HMI.

The stand-by pump shall operate automatically as dictated by the circulating line flowswitch. If operating pump is running and the flow switch indicates low flow for more than10 seconds, a low flow alarm is triggered, the stand-by pump is started, and operatingpump is stopped. If flow didn’t get back to normal level in 5 seconds, the stand-by pumpwill be stopped and an alarm “Recirculation circuit no flow detected” will be issued.

The stand-by pump shall also operate automatically if the operating pump experiences afailure. The Controller shall track accumulated working hours and automatically cycle thestand-by pump based on running time. One pump should always being running tosupply hydraulic pressure for the operation of the blast furnace equipment.

The circulation pumps have the following permissives

Description Permissive(state of input)

Hydraulic Emergency Stop On(=OK)*

Suction Valve Open On(=OK)*

Low Low Level in Hydraulic Tank On(=OK)*

Hydraulic Circulating Flow OK On(=OK) 30 sec time delay


Pump Available from Motor Overload On(=OK)** hardwired, ** not active in Local mode

To keep the standby pump in good condition it will be run occasionally for a short periodof time. To accomplish this if the operating pump has run 150 hours total hours since thelast time the standby pump has been run then the standby pump will be started and theoperating pump stopped. The standby pump will run for 30 minutes and then theoperating pump will be restarted and the standby pump stopped. This will have the affectof running the standby pump for 30 minutes approximately once a week.

The time periods for Operating and Standby pumps can be adjusted through HMI by

authorized personnel. If desired, Standby pump running time can be set to zero whichwill disable automatic switching. In this case, Standby pump manual running will berequired from time to time to make sure it is in good shape.

5.3.5 Hydraulic Cooler

The hydraulic cooler is a water oil heat exchanger located in the circulation line.

In automatic if the permissives are met, cooling water solenoid valve will turn on, whenthe hydraulic fluid is above 50°C and off below 35°C. This will allow cooling water to flowthrough the cooling heat exchanger.





The cooling water valve has the following permissives


Hydraulic Emergency Stop On(=OK)

Hydraulic Tank Temperature above35 °C

On(=above 35 °C )**

* hardwired, ** not active in Local mode

5.3.6 Hydraulic Circulating Filter

The hydraulic circulating loop has a filter with a differential pressure switch to monitor when it is time to change the filter. If the pressure switch opens an alarm will be issuedon the HMI. This alarm will be latched and must be reset by the operator through theHMI.

5.4 Hydraulic HMI Controls

The HMI will contain one main Hydraulic graphic display of the hydraulic system. Theprocess graphic will display the complete status of the Hydraulic system, includingreadouts and displays for:

- current pressures,- oil level,- temperatures,- status of valves and pumps- status of accumulators.

The screen will have the following operator controls:

- Mode selection of the hydraulic system- Mode selection for valves and motors- Controls for valves and motors in Manual mode





6 Greasing Functional description

The BLT has an automatic greasing system to provide lubrication to critical componentson the Furnace Top. The system consists of two different greasing zones each operatesindependently using a common pair of pumps and grease tanks. The zones grease thefollowing areas

- Fast Zone: cycles every 45 minutes (chute transmission and planetary gear)- Slow Zone: cycles every 8 hours (mechanical stockline winch, lower seal

valves, lower material gates, upper seal valves, distribution rocker, conveyor belt, equalizing valves, relief valves, bleeder valves).

The Fast Zone (chute and gearbox greasing) has individually monitored grease pointswhile Slow Zone only monitors the end of line switches. Continuous greasing can be

activated for each greasing cycle by the operator or automatically for fast cycle based ongearbox temperature conditions.

6.1 Greasing Operating Modes

The Greasing systems normal mode is automatic which is the recommended operatingmode for the system. The Greasing system can also be operated in Manual mode fromthe HMI or Local Mode from the pushbutton stations. Note the entire Greasing systemhas one set of Automatic/Manual controls.

CirculatingPumps

Pressurepumps

Accumulators







On transition to automatic the system will place the valves or pumps in the correct statebased on the current system conditions.

6.1.2 Manual Mode

On transition to manual the devices will maintain their last state. Once in manual thecontrol of the devices will be based on the Manual controls from the Greasing HMIscreen. In Manual mode all pump interlocks will be active.

6.1.3 Local Mode

Local control of the greasing equipment is provided through the local pushbutton stationand is available for motors only.

On transition from remote to local the devices will maintain their last state. Once in localthe control of the devices will be based on the pushbuttons at the Greasing LCP. InLocal mode all pump interlocks will be active.

On transition from Local back to Remote the system will switch to Manual mode.

Note local control is still through the Controller.

6.2 Central Grease Pumps with Grease Reservoir The system works on the two-line greasing principle. Two greasing pumps are installed.One is in operation and the other is a stand by pump. They are common for the twocycles: the fast cycle (45 minutes, half-cycle 22.5 minutes) and the slow cycle (8 hours,half cycle 4 hours). Each grease pump has its own grease reservoir.

The grease reservoirs have high, low, and low-low level switches. The high and low levelswitches are for monitoring only; the low-low level switch is used for monitoring and toprevent the associated grease pump from running.

The grease Pump1 run permissives are;


Emergency Stop On(=OK)*

Grease Reservoir 1 Low-Low Level On(=OK)

Grease Pump 1 High pressure On(=OK)

One of the changeover valves is inactuated position

Pump 1 Selection valve open ZSO=On





Pump 2 Selection valve closed ZSO=Off

Return Valve1 open ZSO=On

Return Valve2 closed ZSO=Off



** not active in Local mode,* hardwired

The grease Pump2 run permissives are;


Emergency Stop On(=OK)*

Grease Reservoir 2 Low-Low Level On(=OK)

Grease Pump 2 High pressure On(=OK)

One of the changeover valves is inactuated position

Pump 2 Selection valve open ZSO=On

Pump 3 Selection valve closed ZSO=Off

Return Valve2 open ZSO=On

Return Valve1 closed ZSO=Off



* hardwired, ** not active in Local mode

Since there are manual ball valves that must be set correctly to isolate the pump outletfrom the opposite grease pump and reservoir, switching the standby and primary pumpswill not be cycled automatically.

6.3 Grease Valves

The automatic grease valves only interlock is the Greasing E-stop which will stop themovement of the valves at their current position, done via Controller.

6.3.1 Change Over Valves

There are four Change Over valves, one per each zone per each line. The valve for theline required to be greased shifts to the actuated position to connect the pump pressureoutlet to the zone for the grease cycle and then returns to the released position when thehalf-cycle is complete. The Change-over valves are motorized valves. The motor requires a reversing contactor.

To send the valve to the P to A position, the P to A output is turned on and the valvemoves to the P to A position. An internal contact not available to the Controller stops the





movement. The output should be left on as long as the valve is required to be in the P to A position.

To send the valve to the P to B position, the P to B output is turned on and the valvemoves to the P to B position. An internal contact not available to the Controller stops the

movement. The output should be left on as long as the valve is required to be in the P toB position.

Confirmation of the valve being in correct position will only be through the End of Linepressure switches turning on correctly.

6.4 Grease Sequences

When the preset time delay has elapsed, the Controller automatically shifts the change-over valve. Once the change-over valve is in position the operating pump turns on tocarry out a half-cycle.

Once the pump turns on, the lubricant flows through the pressure line into the selectedgrease main lines.

As delivery continues, the pressure in the main line rises until the delivery resistance(the minimum operating pressure of the metering valves) and the entry resistance at thelubrication points are overcome. Only then are the control and measuring pistons of themetering valves activated, discharging a metered quantity of lubricant to the lubricationpoints.

After all affected metering valves finish operation, half of the connected lubrication pointsof the activated zone are supplied with lubricant.

When the first half-cycle is complete, pressure rises again until the change-over pressure, set on the end-of-line pressure switch, is reached. When this occurs, theController turns off the pump and the delay timer starts again. The Controller alsoswitches the change-over valve back to the relief position.

When the set delay time has elapsed once more, the other lines changeover valve is setto pressurize and the pump re-starts. The rise in pressure pushes the pistons of themetering valves in the other direction, causing the second half of the lubrication points toreceive lubricant.

Once the end-of-line pressure switch senses the predetermined change-over pressure,the Controller once again turns off the pump, switches the change-over valve to the relief position and starts the delay timer, thus bringing a full lubrication cycle to a close. Allconnected lubrication points in this zone have now received their pre-selected meteredquantity of lubricant.

Note : If start times for different zone cycles coincide, once the one zone has finished thechange-over valves will switch positions and the other zones cycle will run immediatelyfollowing the first cycles completion.





The grease cycle for each zone must complete in a pre-determined time. If the timeelapses then the cycle stops and an alarm is issued. The metering time supervisorytimer should be set at commissioning to the normal operating time of the grease zoneplus a safety margin of 3 minutes.

In the event of an E-stop during the grease cycle the pump will stop and all valves willhold their last state. The system will be placed in manual and the cycle will need to befinished manually.

6.5 Monitoring of Metering valve in Fast Cycle Zone

The planetary gear box and chute lilt bearing grease points are monitored with limitswitches. During the grease cycle the limit switches must transition from off to on or onto off depending on the whether line A or line B is being greased. During the cycle eachpoint will be monitored for transition and at the end of the cycle all the points should bein the same position

6.5.1 Failure of Metering Valves in Fast Cycle Zone

The following monitoring sequences must occur (in Automatic and Manual modes) if there is failure of metering valves serving the chute transmission gear and planetarygear.

If 1 to 5 of the 12 metering device limits switches fail (ZS 5716-AA – to AD and ZS 5716-BA to BC and ZS 5716-CA to CD and ZS 5716-DD), the chute rotation movement mustbe stopped after 3 hours. The chute angle must be positioned at 20 degrees and thechute tilting must be stopped. If a material discharge from a material hopper is inprogress, it is completed prior to stopping chute rotation.

If 6 or more of the 12 metering device limit switches fail, the chute rotation movementmust be stopped after 30 minutes and the chute must be positioned at an angle of 20degrees and the chute tilting must be stopped. If a material discharge from a materialhopper is in progress, it is completed prior to stopping chute rotation.

The two timers will be reset if one complete greasing cycle (Line A and B) has beendone without failure.

If 1 or more of the 3 metering device limit switches (ZS 5716-DA to DC) fail, the chuterotation movement must be stopped after 30 minutes and the chute angle must bepositioned at 20° angle. If a material discharge from a material hopper is in progress, it iscompleted prior to stopping chute rotation.

6.6 Continuo us Greasing of the Chute Transmission Gear

The Controller enables a selection for automatic and continuous greasing for the chutetransmission gear lubrication cycle (Zone 1).

In continuous greasing mode, a lubrication cycle begins immediately after the precedingcycle is complete. The changeover valves switch positions connecting line A and B tothe pump line, and the pump does not stop but instead continues to operate.





Continuous greasing occurs when the thermocouples installed in the chute transmissiongearbox monitor a temperature of 100°C on the tilting slewing ring support; or if ahousing gas temperature of 110°C. If either of these temperature setpoints is reached,the Controller automatically directs the Fast cycle to continuously operate until thetemperature has dropped to below 100°C. or 110°C, respectively.

Note: In normal operating temperatures, the Fast Zone lubrication cycle must beinterlocked with the chute rotation drive so that the cycle is interrupted when the chuterotation drive is stopped for more than 30 minutes. This is to prevent over-greasing of the transmission gearbox slewing rings. However, if the chute rotation drive is stoppedbut the temperature inside the gearbox reaches the alarm settings of 100°C and 110°C,continuous greasing for Fast Zone must begin and continue until the temperature dropsbelow alarm levels.

6.7 Greasing HMI Screen

The HMI will contain one main graphic display of grease system. The process graphicwill display the complete status of the Grease system. The following status information isdisplayed:

- Grease Tank Level switches status- Grease pump Operating /Standby selection status- Grease Pump pressure status- Manual Valve Position Status- Change-over valve status

Fast Zone

- Chute Transmission Gear Metering Valve Switches- Top Ring Temperature (°C)- Main Bearing Temperature (°C)- Main Housing Temperature (°C)- Continuous Greasing Status (On / Off)- Time Until Next Cycle- Zone End of Line Pressure Status- Fault Status- Remaining time until chute rotation stops (after metering valves failure)

Slow Zone

The following status information is shown:

- Time Until Next Cycle- Zone End of Line Pressure Status- Cycle in Progress Status (First / Second)- Fault Status

The screen will have the following operator controls

- Auto/manual mode selection of the Grease system- Manual control of the Changeover Valves, Grease Pumps





Failure of the pressure transmitter or the temperature transmitter will prevent the supplyvalve from opening.

Four identical circuits supply steam to the upper and lower seal valve seats. The seattemperature is set to a range of 90 C to 105 C. The temperature is controlled by

opening automatic shutoff valves according to the actual temperature as measured bythe upper and lower seal valve RTDs. When the seat temperature reaches 130 C, analarm activates to alert the operator to check the functioning of the automatic shutoff valves.

7.1 Steam Heating Valves con trol

The steam heating valve cycle on and off based on the temperature of the seat. Thevalves open if the seat temperature is at or below 90 C and the valve will close at105 C.

When the seat temperature reaches 130 C, an alarm activates to alert the operator tocheck the functioning of the automatic shutoff valves.

The steam heating valve interlocks are based only on the seat temperature

In auto, the valve opens and closes on temperature as described above

On transition from Auto to Manual, the valves will maintain their last state.

In Manual, the valves can be opened if the seat temperature is below 130 C. There areno interlocks on closing the steam valves in manual.

The Heating system can be taken out of service through HMI. In this case supply controlvalve and shut-off valves at the seals close.

No local controls provided for the subsystem.

7.2 Steam Heating HMI screens

The HMI will contain one main steam heating graphic display of steam system and atrend screen of the seat temperature of the seats and the steam system pressure. Theprocess graphic will display the complete status of the steam system. Including readoutsand displays for:

current pressure, temperatures, status of valves, position reference for steam pressure control valve

The screen will have the following operator controls

Steam Heating system mode switching Mode switching and manual controls for valves





8 Cooling Functional description

8.1 Water Cooling System Overview

The Bell-Less Top closed loop water cooling system is supported by two circulationpumps (one in operation, one as standby) that maintain a continuous water flow rate of 25 m 3/hr. Due to normal water loss from evaporation, leaks and flushing requirements,make-up water is added to the system as needed.

In this closed loop circuit, process water is pumped from a reservoir through a self-cleaning hydro-cyclone filter to a water/water heat exchanger. On the secondary side of the heat exchanger, service water circulates to cool the process water.

Cooled process water travels from the heat exchanger to the upper rotating trough of thechute transmission gear. From there, it flows by gravity through the serpentines to the

lower static trough of the chute transmission gear. The accumulated process water isthen routed back to the process water reservoir.

The cooling system must operate continuously, even during blast furnace shutdown.Cooling is stopped only when working on the cooling circuit. In the event of anemergency, process water cooling can be suspended for a maximum of six hours duringblast furnace operation, with the furnace top cooled via emergency nitrogen. Operatorsmust continually monitor temperatures in the chute transmission gear while the coolingsystem is non-operational.

8.2 Cooling Water Operating Modes

The cooling water systems normal mode is automatic which is the recommendedoperating mode for the system. The cooling water system can also be operated inManual mode from the HMI or Local Mode from the Local Control panel. Note the entirecooling water system has one set of Local/Remote and Automatic/Manual controls.



On transition to automatic, the system will place the valves or pumps in the correct statebased on the current system conditions.

8.2.2 Manual Mode

On transition to manual, the devices will maintain their last state. Once in manual thecontrol of the devices will be based on the Manual controls from the cooling water HMIscreen. In Manual mode all interlocks will be active.





8.2.3 Local Mode

The Cooling Water Local Mode is available for pumps only and is through localpushbutton stations. On transition from remote to local, the devices will maintain their last state. Once in local the control of the devices will be based on the local pushbuttons

and only the minimal safety interlocks will be active in the control.

On transition from Local back to Remote, the system will return to Manual.

Local control is still through the Controller.

8.3 Cooling Water Equipment

The cooling water equipment is shown on the Cooling Water P&ID, see document list for reference.

8.3.1 Circulation Pumps

There are two circulation pumps used to circulate the cooling water through the system.One pump is operating and the other pump is the stand by pump. The standby pump willstart if the operating pump stops for any reason or there is a cooling water low flowalarm (flow rate below 10m 3/hr for 10 seconds). The low flow alarms also stopsoperating pump. Note during the hydro-cyclone flushing a low flow will occur and thepumps will continue to run and the alarm will be inhibited.

The gearbox cooling water pumps have the following permissives.


Cooling Water E-stop On(=OK)*

Low Low Level in Cooling Water Reservoir

On(=OK)*

High Level Switch 1 in GearboxUpper Trough (10 sec Delay)

On(=OK)**

High Level Switch 2 in GearboxUpper Trough (10 sec Delay)

On(=OK)**

High Level Switch in Gearbox Lower Trough (10 sec Delay)

On(=OK)**

Gearbox Cooling Water Low Flow Flow>10m3/h**


Pump available from motor overload On(=OK)*

Suction Valve open On(=OK)** hardwired, ** not active in Local mode

Maintaining a reliable back-up pump is important to insuring the high availability of thecooling system. Therefore one pump will be the main operating and as such will rununless there is a fault. To keep the standby pump in good condition it will be run





occasionally for a short period of time. To accomplish this if the operating pump has run150 hours total hours since the last time the standby pump has been run then thestandby pump will be started and the operating pump stopped. The standby pump willrun for 30 minutes and then the operating pump will be restarted and the standby pumpstopped. This will have the affect of running the standby pump for 30 minutesapproximately once a week.

The time periods for Operating and Standby pumps can be adjusted through HMI byauthorized personnel. If desired, Standby pump running time can be set to zero whichwill disable automatic switching. In this case, Standby pump manual running will berequired from time to time to make sure it is in good shape.

8.3.2 Reservoir

The gearbox cooling water reservoir feeds water to the cooling water pumps andreceives the gravity feed return water from the gearbox cooling serpentines. The tankhas the following devices

- make-up water feed valve used to maintain a normal water level in the tank- drain valve for flushing water from the tank- level transmitter for continuous monitoring of the tank level Range 0-

2500mm- High level switch at 2040mm for preventing overflowing the reservoir - Low Level switch at 1180mm for protecting the cooling water pumps

In order to maintain good quality cooling water in the reservoir, once every eight hours,the process water reservoir is drained and refilled with fresh makeup water. In thisscheduled drain/refill cycle:

- Automatic drain valve opens. When the water level in the process water reservoir reaches 1740 mm per, the automatic drain valve closes.

- When LT-5311 indicates a water level of 1740 mm, the automatic makeupwater valve opens. This valve closes when the water level in the processwater reservoir reaches 1890 mm per.

This eight-hour drain/refill cycle is timed so as to alternate with the eight-hour flush cycleof the hydrocyclone filter. This results in a four-hour time interval between the twoalternating cycles.

The Controller will close the automatic drain valve and make-up water valve if the E-stopis pressed.

8.3.3 Reservoir Level Monitoring

The reservoir level is monitored using the level transmitter, the high level switch and thelow level switch.

The automatic makeup water valve opens when the water level in the process water reservoir reaches the minimum of 1740 mm. If the automatic makeup water valve opensat any time other than during the drain/refill cycle of the process water reservoir or theflush cycle of the hydrocyclone filter, the system alarms to indicate leakage in the circuit.The system also alarms when the water level falls to 1330 mm. At this level the





automatic drain valve and the hydrocyclone flush valve will be closed, and when it fallsto 1180 mm as indicated by the low level switch, the circulation pumps stop.

Note: The amount of time the makeup water valve is open is checked and an alarm isactivated if the makeup water valve stays open for more than five minutes. This protects

against failures in the level measuring system.If the water level reaches 2040 mm, per the High level switch, the system alarms andautomatic drain valve opens. When the water level falls to 1890 mm, the automatic drainvalve closes.

If the low level switch indicates a low level alarm and the make-up water valve is openand the level transmitter indicates the water level is rising and has passed the low levelswitch. Then an alarm is activated that the low level switch has failed and the make-water valve will be closed based on the level transmitter at 1890mm

8.3.4 Hydrocyclone

An automatic sludge flush of the hydrocyclone filter occurs every eight hours. Aspreviously noted, timing of the sludge flush cycle alternates with the makeup water drain-refill cycle.

In the flush cycle Hydrocyclone Flush valve opens for 30 seconds allowing filter flushing.

The Controller will close the automatic hydrocyclone flush valve if the E-stop is pressed.

8.3.5 Heat Exchanger

Heat exchangers have no automatic control. If f low switch on the outlet of the secondarycooling circuit indicates low flow, an alarm is issued.

8.3.6 Gearbox Temperature Monitoring

Operating the main gearbox at high temperature can cause premature failure of thegearbox. Therefore, the temperatures in the gearbox are monitored.

Description Setpoint ActionUpper trough gearboxHIGH-HIGH temperature

>100°C or High alarmpresent for > 20

minutes

Stop Chute Rotationand sent tilt to neutral

positionUpper trough gearboxHIGH temperature

>90°C Continuous greasingstarts

Upper trough gearboxLOW temperature

<25°C Warning

GEARBOX BEARINGHIGH-HIGH temperature


minutes


position

GEARBOX BEARING >90°C Continuous greasing





HIGH temperature startsGEARBOX BEARINGLOW temperature

<25°C Warning

Inside Gearbox casingTE-5304-B HIGH-HIGH

temperature


minutes


positionInside Gearbox casingHIGH temperature

>100°C Continuous greasingstarts

Inside Gearbox casingLOW temperature

<25°C Warning

8.4 Gearbox Nitrogen and Purging

The main gearbox is pressurized with nitrogen to prevent blast furnace gas and dustfrom entering the main gearbox housing. This pressurization is accomplished by amechanical flow control and manual valves. There are no electrical controls associated

with the gear box pressurizing nitrogen, however there is monitoring of the critical valvesas well as monitoring of the incoming nitrogen pressure, temperature and flow.

In the event of a failure of the cooling water system the main gearbox can be cooled withnitrogen. This is accomplished via a manually operated valve. This valve has limitswitches to monitor its position.

In the event of an over temperature (above 120 deg C) in the Valve Actuation Unit theemergency nitrogen cooling valve will open.

8.4.1 Air Purging Fan An air purge fan is installed on the gearbox and valve actuation unit nitrogen coolingsystem. The fan is run when whenever maintenance is preformed in these areas toensure the nitrogen is removed and there is oxygen available.

The fan is only run in Manual or Local mode and the permissives to run the fan are;


Cooling Water E-stop On(=OK)*

Local mode selected OnMain N2 Inlet Valve Closed

Main N2 Outlet Valve Closed

Main N2 Relief Valve Opened

Air Purge Inlet Valve Opened

Air Purge Outlet Valve Opened

Air Purge Relief Valve Closed

Fan available from MCC On(=OK)

Fan available from motor overload On(=OK)*





8.4.2 Nitrogen Valve Posit ions

The following table summarizes the correct manual valve positions for the various statesof the furnace

Description Normal EmergencyCooling

Air Purge

Main N2 Inlet Valve Opened Opened Closed

Main N2 Outlet Valve Opened Opened Closed

Main N2 Relief Valve Closed Closed Opened

Air Purge Inlet Valve Closed Closed Opened

Air Purge Outlet Valve Closed Closed Opened

Air Purge Relief Valve Opened Opened ClosedGearbox N2 Valve Opened Opened Opened

Gearbox Emergency N2valve

Closed Opened Opened

Valve Actuation Unit N2Valve

Opened Opened Opened

Valve Actuation UnitEmergency N2 Valve

Closed Opened Opened

8.5 Cooling Water/Nitr ogen HMI Contr ols

The HMI will contain one main cooling water graphic display of water system, a trendscreen of gearbox temperatures. The process graphic will display the complete status of the cooling water system, including readouts and displays for:

- current pressures,- flow rates,- water level,- temperatures,- status of valves, and pump(s)

- operating hours on the circulating pumpsThe screen will have the following operator controls

- trigger a reservoir tank flushing cycle- trigger a hydro cyclone flushing cycle- selection of pumps auto or manual; and start and stop the pumps once in

manual. The operating pump cannot be switched to manual mode.- selection of the Make-up water and flushing valves; auto or manual control

and the manual open and close controls once in manual



GearboxTemperatures

Manual ValvesStatus Displayed

Tank Level andStatus Displayed

Circulatingpumps