8/10/2019 Bulletin 23 - Installation of Supply and Demand Side Controllers for Compressed Air System

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Energy Efficiency BulletinEnergy Efficiency BulletinCase Study Bulletins from CII-Sohrabji Godrej Green Business Centre

Installation of Supply & Demand Side Controller forOptimisation of Compressed Air System

Octoberulletin No. 23

Company details

Project details

Optimizationsystem

Dalmia Cement (B) Ltd started cement production operations in1939 at Dalmiapuram. Then, the capacity of this Polysius plant was250TPD clinker production.Presently the total capacity is 4600 TPDof clinker production, due to continuous up gradation. How ever, stilltheold machinery of 1939 plant is in operationcontinuously.

Over the years, 39 compressors (Reciprocating as well as Screwtype) of different makes with a total installed capacity of 20081m /hwere installed to meet compressed air demand for various

applications.The totalinstalleddrive power is 1908.5 Kw.Out of these, 20 compressors with total capacity 17,749 m /h andrated power of 1631 KW were in old plant (VRM-1, M.H, CVRM, PHand PolysiusLine).

The compressors at old plant were initially installed near the userend. However, over a period of time these compressor lines wereinterconnected with the result that any compressor's air could besupplied for any application resulting in un-optimized use of air andconsequent wastage of energy.

To monitor the energy consumption, the plant team had installedenergy meters for individual compressors in the old plant. Theenergy consumption was recorded on a daily basis.The total energyconsumed by all compressors was approximately 2,41,000 units permonth.

From the preliminary study conducted by the plant team based oncompressed air requirement of various users, it was concluded that12Screw compressorswithtotalinstalled capacityof 9507 (andpower consumption of 1003.5 kW) could meet the compressed airdemandfor allsections- VRM-1,CVRM,MH, PH andPolysius Line.

The plat team stopped the rest of the compressors. It was observedthat excess capacity existed even than and that the continuousoperationof 12 Screwcompressors wasalso notrequired.

However, further optimization and consequent energy saving waspossible only by installing supervisory monitoring and controlsystemto operate all screwcompressors.

3

3

3

m /h

Supply side and demand side control systems were commissionedlater.The modified systemlayoutis as shown.

Basically this system classified plant air applications in two groupsone set of users that consumed compressed air at steady rate(process applications) and the other that consumes at cyclic pattern(fluxo pump applications). The compressed air lines weresegregated forming twoheaders - onededicated to each group.

Select applications were provided with pressure/flow controllers

where application pressure could be set. All twelve scrcompressors were connected to central Controller which can switon andoff each compressor dependingon demand.

All screw compressors supply air to process header at prespressure. From this header, process applications received through flow controller at lesser but steady pressure. Tcompressors are run in such a manner that the header pressuremaintainedwithin a set range.

The Demand side controller systems are connectedto 4 networks

Central Controller to controlscrew compressor operation

meet theplantdemand.

a) Demand side controller - 1000-SCFM for CVRM M

application;dischargeset pressuresat 62 psig (4.36 kg/cm

ELGI - 2 nos

110 kW/ 700 scfm

CVRM Mill

Symbols:Compressor Receiver Isolation valve

DDryer

ELGI - 2 nos

90 kW/ 525 scfm

ELGI

90 kW/ 525 scfm 7

ELGI 3 nos

75 kW/ 315 scfm

10

1 2 3

D D D

4

D

Polysius

Kiln Shell Cooling

Ball Mill - Osapa B/F

VRM-1 Hopper

Mill House

CVRM

Packing

House

ControlAiR Controller

GE 10 500 scfm

ControlAiR Controller

GE 10 500 scfm

ControlAiR Contro

GE 10 - 500 scfm

Silos

ControlAiR Controller

GE 20 1000 scfm

ELGI

20 kW/ 100 scfm 5

Packing

Machines

VRM-1 Fluxo Pump

11

ELGI

90 kW/ 525 scfm 8

ELGI

90 kW/ 525 scfm 6

12Dry FlyAsh Unloading

FLUXO PUMPS Header (6 ) inter-connecting

All the PumpingApplication compressors

ELGI

90 kW/ 525 scfm9

Polysius Fluxo Pump

1.7

1.2

ADDITIONAL

15 m3

Auto shut-off valve

Dry FlyAsh Unloading

8 88

PROCESS Header (4 ) inter-connecting

All the ProcessAir compressors

SX-8

COMPRESSOR OPTIMISATION - SYSTEM LAYOUT

Demand side controller

8/10/2019 Bulletin 23 - Installation of Supply and Demand Side Controllers for Compressed Air System

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F o r f u r t h e r d e t a i l s c o n t a c t

,

Survey No 64, Kothaguda, Near Hitech CityHyderabad - 500 032

Tel: 040-23112971 73 Fax: 040-23112837Email : k.s.venkatagiri@ciionline.org / k.sivaram@ciionline.o

www.greenbusinesscentre.com

Mr K S Venkatagiri / Mr K Sivaram

About CII& CII-Godrej GBC

About 3 Country Energy Efficiency

CII is a non-government, not-for-profit, industry led and indusmanaged organisation, playing a proactive role in Indidevelopment process. Founded over 112 years ago, it is Indiapremier business association, with a direct membership of ov6500 organisations from the private as well as public sectoincluding SMEs and MNCs, and an indirect membership of ov90,000 companies from around 350 national and regional sectoassociations.

Cll-Godrej GBC is a Centre of Excellence in Energy Efficiency, GreBuildings, Renewable Energy, Water, Environment & Recycling aClimate Changeactivities in India.

The Project "Developing Financial Intermediation Mechanisms fEnergy Efficiency Projects in Brazil, China and India" aimed substantially increase investments in energy efficiency by tdomestic financial sectors in Brazil, Chinaand India.

The project was a partnership between the World Bank, the UnitNations Environment Programme (UNEP) through the UNEP RisCentre on Energy, Climate and Sustainable Development (URC), ainstitutions in Brazil, China and India. Additional information available at

This Energy Efficiency Bulletin comprises of a series of case studon successful energy efficiency projects implemented by Indiindustry. The bulletin is supported under the "3 Country Einitiative and by USAID.

www.3countryee.org

Cost benefit analysis

Investment Rs 1.83 million

(USD 0.045 million)

Annual savings Rs 2.33 million

(USD 0.058 million)

Payback 10 months

Mr N Gopalaswamy

Dalmia Cement (Bharat) Ltd.Whole Time Director

DalmiapuramTrichy (District)Tamilnadu, IndiaPIN - 621 651Tel: 04329-235123; Extn: 503, 203Fax : 04329-235111Email: gswamyn@dalmiacement.com

b) Demand side controller - 500-SCFM for Packing Silos

application;discharge setpressures at 30 psig (2.10 kg/cm ).

c) Demand side controller - 500-SCFM Ball Mill; discharge set

pressuresat 71 psig (4.99 kg/cm ).

d) Demand side controller - 500-SCFM for Polysius Kiln Shell

Cooling application; discharge set pressures at 30 psig (2.10

kg/cm ).The Supply side Controller wasconnectedto process header. Allthe12nos. of screw compressors were operated with optimizedpressure setting of 73 psig to 78 psig (Average 75 PSIG or 5.27kg/cm ).

Commissioning of the entire system was done after a detailedfeasibility study by the vendor. Segregation of compressed air linesand installation of new headers were taken up during planned shutdown. The complete integration of the system with the existingsystem wasdone in a staggered manneras andwhen therespectiveplantwas available formodifications.

Due to advancements in automation, it is possible to preciselycontrol the bandwidth of generation pressure, matching it with thedemand, on a real time basis.Allindustries are users of compressedair & hence saving potentialexists acrossindustry.

The plant invested about Rs 1.83 million for implementing theproject.The investment was taken up fully with internal funds.

The project resulted in reducing the Compressed air pressurevariation was reduced significantly. The pressure variation wasboughtdown to a narrowband - 4.97 to5.31bar.

Only 12 compressors in operation at present as against thepreviousoperation of 20 compressors. This had resulted saving the unloadpower consumption to a great extent and reduced maintenancecost.

Energy Savings with supply & demand side controller - 3,060 kWh /day.

The annual savings achieved is.The investment made is about.The simplepaybackperiodis

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2

Rs 2.33 million (USD 0.058million) Rs 1.83 million (USD 0.045million) 10 months.

Issues facedduring implementation

Comments bythe plant team

Financing of the project

Results of theproject

Financial benefits

Benefits of the project

Segregation of compressed air system

based on pressure

Online monitoring and control for both

supply and demand

Energy savings of 27%