PRESENTATION OF ENERGY EFFICIENT TECHNOLOGIES AND BEST PRACTICES FOR

ENERGY CONSERVATION IN CEMENT INDUSTRY.

AEEE ENERGY EFFICIENCY CONCLAVE -2017

Prepared by: MANGALAM CEMENT LTD, INDIA

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In order to achieve this objective it was necessitated to undertake following energy saving

measures in our plant:

1) Up gradation of kiln -1 from old vintage 4stages cyclone pyro-system to most energy efficient

6-stage pyro-system with latest energy efficient FLS :SF :Cross-Bar Clinker Cooler, Vertical Atox

Coal Mill and Vertical Atox Raw Mill in place of in-efficient old Ball Mills.

2) Installation of VVVF (MV) Drive for 1250 KW HT Motor for VRPM Main Drive in Cement Mill-1.

3) Installation of DD cones in all the 4 cyclones of Cement Mill-II dynamic separator to reduce

pressure drop, along with replacement of double flap valves by rotary air locks, to reduce false

air ingress in cyclones.

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ABSTRACT:

1) Up-gradation of Unit-I Clinkerisation section :

The old 4 stage in efficient cyclone preheater kiln, Ball Mill for Coal Mill and Ball Mill for Raw

Mill were having more specific electrical power consumption up to Clinkerisation i.e. 70.18

kwh/ton of clinker and up to cement 95 kwh/ton and thermal specific energy of 860 kcal per kg

of clinker. Hence, unit-1 was upgraded with energy efficient 6 stage preheater, precalciner &

efficient FLS Make : FS: Cross-Bar Cooler along with Atox VRM (Vertical Raw Mill) & Atox VCM

(Vertical Coal Mill) for clinker production capacity up gradation from 1750 TPD to 3000 TPD and

also reduction in SEC (Specific Electrical Energy Consumption) and Specific Thermal Energy

Consumption.

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JUSTIFICATION IN SELECTING THE ABOVE PROJECTS:

2) Installation of VVVF Drive (MV Drive) for 1250 kW HT Motor for VRPM (Vertical Roller

Pressed Mill) Unit-I Cement Mill:

Installation of medium voltage variable frequency drive for 1250 KW HT Motor of VRPM Main

Drive of unit-1 cement mill. The start and stop of VRPM, HT Motor was frequent due to filling of

cement mill surge hopper because VRPM main drive was running at full speed. This was causing

mismatch of running hours of cement Ball Mill and VRPM. In order to get continuous running

of VRPM along with Ball Mill running, the speed of HT Motor was reduced with the installation

of VVVF (MV) Drive.

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JUSTIFICATION IN SELECTING THE ABOVE PROJECTS:

Cement Mill-2- installation of DD (De Dusting) cones in all the four Sepol Cyclones to reduce

pressure drop.

The conventional cyclones separation efficiency was not up to the expectation level. We have

designed, fabricated and installed 4 Nos De- Dusting (DD) cones into existing cyclones of

dynamic separator for better efficiency.

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JUSTIFICATION IN SELECTING THE ABOVE PROJECTS:

The consistent and continual improvement of plant energy conservation measures got impetus by the following in house projects, planning, designing, fabrication, erection and commissioning:

Unit- I, Kiln: * Replacement of chain type bucket elevator with belt type bucket elevator in kiln feed system.* Replacement of old in-efficient air separator with high efficiency dynamic separator in Raw Ball Mill.

Unit-2, Kiln:* Increase in TA- Duct Dia from 1.74 m to 2.5 m.* Increase in height of calciner by 7.8 m and total length by 15.6m * Increase in down comer duct area from 5.72 sq.m. to 9.99 sq.m for reduction in pressure drop.

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OTHER ENERGY EFFICIENCY MEASURES TAKEN BY MCL

.

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Figure 1: Modification of Unit-I Cement Mill (Installation of MV drive in VRPM main drive)

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INTRODUCTION OF COMPANY:

Mangalam Cement Ltd is a cement unit, belongs to renowned industrial house of B.K.Birla group of

companies, located at Morak, Distt. Kota, Rajasthan, India. The company is presently producing cement

in 43 grades,53 grades and Portland Pozzolona Cement (PPC) using the dry process technology and

marketing under the brand name of “Birla Uttam”. The company started commercial production of

cement in 1980 with an installed capacity of 4 lakh tons cement per annum. The company then took up

two further expansion scheme envisaging increase in the installed capacity from 4 lakh tons to 20 lakh

tons of cement per annum in between 1994 to 2005.The company have recently expanded its clinker

capacity of Unit-I Kiln from 1750 TPD to 3000TPD by up grading its Kiln –I in the year 2013. The

company have also installed a cement grinding unit of capacity of 1.25 million tons of cement in 2014

at Morak. The present cement capacity of the company is 3.25Million Tons per annum.

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UP GRADATION OF KILN-1:

The Kiln-I was earlier 4 stage pre-heater with ball mills

for coal and raw meal grinding circuit where in specific

power consumption of electrical energy as well as

specific thermal energy were more. In order to reduce

the specific energy, it was decided to up-grade the 4 –

stage cyclone pre-heater system to 6 stage cyclone pre-

heater system along with Vertical Coal Mill and Vertical

Raw Mill and Energy Efficient Cross-Bar Cooler in place

of old Ball Mills and in-efficient clinker cooler.Figure 4: 6 STAGE PREHEATER

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THE INVESTMENT AND COST BENEFIT ANALYSIS IS AS FOLLOWS:

Sr no.

Description of items

Electrical Energy Saving per Annum in Lac Unit (kwh)

Thermal Energy Saving per Annum

in Million Kcal

Total Investment(Rs.) in Lacs

Total Saving per Annum in Rs. In

Lac.Pay Back

1.

Up-gradation of 4 stage cyclone pre-heater to 6 stage cyclone pre-heater of kiln.

53.14

121069

15000 3645 4 Years (With actual production).

3 Years ( With Full Capacity)

2.Installation of energy efficient vertical coal mill.

-

3.Installation of Energy Efficient Vertical Raw Mill

-

4. Total

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THE INVESTMENT AND COST BENEFIT ANALYSIS IS AS FOLLOWS:

Saving Calculation: Clinker production : Before up-gradation: 1750 TPD

: After up-gradation: 3000 TPD

Annual Clinker Production Before Up-Gradation in FY: 2012-13 : 569484 Ton

Annual Clinker Production After Up-Gradation in FY: 2014-15 : 840755 Ton

Annual Increase in Clinker production: (840755-569484) = 271271 Ton

Saving in Rupees due to increase in clinker production @ Rs721 per Ton = 721x271271 = Rs1955.9 Lac = Rs.1956 Lac

Thermal Specific Energy Consumption Before Up Gradation: 860 Kcal/Kg of clinker.

Thermal Specific Energy Consumption After Modification: 716 Kcal/Kg of Clinker

Reduction in thermal specific heat consumption = 144 kcal /kg of clinker

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THE INVESTMENT AND COST BENEFIT ANALYSIS IS AS FOLLOWS:

Saving in Thermal Energy in Million Kcal = 144x840755/1000 =121069

Equivalent Saving in Rupees due to thermal saving =Rs1318 Lac

Reduction in electrical energy consumption = (70.18-63.86) Kwhx840755= 53.14 Lac Unit

Saving due to electrical energy=Rs6.98x53.14=Rs370.89 Lac. =Rs.371 Lac

Total Saving in Rupees Per Annum= Rs.1956+Rs.1318+Rs.371=Rs.3645 Lac.

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Installation of VVVF (MV) Drive in 1250 kW HT Motor of Vertical Roller Pressed Mill (VRPM) in Cement Mill -1:

After installation of VVFD the speed of the VRPM got reduced to 80 % which resulted in, not only

reduction of power consumption of HT Motor from 961 kw to 797 kw ,but the reduced speed helped in

maintaining sustainable running of cement grinding Ball Mill and enhanced out put of the Cement Mill

from 110tph to 140tph.

Power consumption before mv drive= 961 kW.

Power consumption after mv drive = 797 kW.

Saving after modification =164 kW.

Saving in Electrical Energy per Annum: 164 kwx3835hrs=628781

Saving in Electrical Energy per Annum: Rs6.98x628781=Rs.43.90 Lac

=Say, Rs44.0Lac (As per actual cement production in FY: 2014-15).

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Installation of VVVF (MV) Drive in 1250 kW HT Motor of Vertical Roller Pressed Mill (VRPM) in Cement Mill -1:

Additional Benefit after Optimization of Process:

The mill output increased from 110 TPH to 140

TPH.

The reduction in total power of cement grinding

from 38 kWh to 30 kWh per ton.

Sr.No.

Description of project

Total Electrical

Energy Saving in

KWH

Yearly Saving in Rs. In Lac

Investment in Rs.in Lac

Pay Back

1.Installation of VVVF(MV) Drive in VRPM 1250 KW HT Motor

6.29 Lac 44.0 90 2 .0 Years

Figure 5: VVVF (MV) DRIVE

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Installation of DD Cones in Unit-2 Cement Mill:

All the four cyclones of Cement Mill-2 dynamic separator were modified byinserting de dusting cones to achieve better separator efficiency. Also doubleflap valves below cyclones were replaced by rotary air locks to minimizeingress of false air.

Additional Benefit:Along with power saving it has also improved separation efficiency in thecyclones which has resulted in remarkable reduction in the wear of Sepol fanimpeller.

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Installation of DD Cones in Unit-2 Cement Mill:

Sr. No. Description of project

Electrical Energy

consumption in kw before installation

Electrical Energy consumption in

kw after installation

Electrical Energy Saving per

Annum(kwh/Annum)

Saving in Rs. In Lac

per AnnumInvestment in Rs.in Lac

Pay Back

1.

Installation DD cones in all four Sepol Cyclones to reduce pressure drop along with replacement of double flap valve with rotary air lock to arrest leakages.

540 458 132194 9.23 7.21 9 Months

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85.61

82.55

78.2380.74

78.27

75.44 74.73

73

78

83

88

2010-11 2011-12 2012-13 2013-14 2014-15 2015-16 2016-17

kwh/ton of cement

18

869860

803

716 709699

760 765 764755 748

738

798781 773

739731

720

680

720

760

800

840

880

2011-12 2012-13 2013-14 2014-15 2015-16 2016-17

THERMAL SEC (GCV BASED)

KILN-I

COMBINED

KILN-II

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