Retrofitting and adoption of energy efficient equipment

Better operational control and Optimization

Up gradation of process control and instrumentation facilities

Better monitoring and Management Information System

Active participation of employees and their continued exposure to energy conservation efforts etc.

The improvements in energy performance of cement plants in the recent past have been possible largely due to

Slip Power Recovery System

Variable Voltage & Frequency Drive

Grid Rotor Resistance

Soft Starter for Motors

High Efficiency Fans

High Efficiency Separators

Vertical Roller Mill

Pre-Grinder/Roller Press

Low Pressure Preheater Cyclones

Multi-channel Burner

Bucket Elevator in place of pneumatic conveying

Fuzzy Logic/Expert Kiln Control System

Improved Ball Mill Internals

High Efficiency Grate Cooler

Plugging of leakages in kiln and preheater circuit, raw mill and coal mill circuits Reducing idle running of equipment Installation of Improved insulating bricks/blocks in kilns and preheaters Effective utilization of hot exit gases Optimisation of cooler operation Optimum loading of grinding media/grinding mill optimisation Rationalization of compressed air utilization Redesigning of raw mix Installation of capacitor banks for power factor improvement Replacement of over-rated motors with optimally rated motors Optimisation of kiln operation Changing from V-belt to flat belt

Operational Control and Optimisation

Energy Conservation Measures in Cement Industry

SHORT TERM MEASURES

Roughly about 2 – 5% reduction is possible by adopting the following simple short term measures.

Increase capacity utilization of primary & secondary crusher

Reduce idle run of crushers and belts

Reduce idle operation of dust collection equipment

MINES

Control raw mill feed size by regular monitoring

Avoid idle running of raw mill conveyor system (auxiliaries) by suitable interlocking

Stop idle running of raw mill lubrication system

Install ‘Isolation’ type dampers in the preheater – raw mill inlet duct and raw mill vent fan – ESP ducts. This reduces air infiltration into ESP fan system when raw mill is stopped

RAW MILL GRINDING & STORAGE

Minimize false air entry in raw mill system

Optimize compressed air consumption for raw meal silo blending

Stop one raw meal silo – vent blower during non – blending period ( batch blending systems)

Optimize air slide blowers air requirement by damper throttling

RAW MILL GRINDING & STORAGE

Improve kiln combustion efficiency

Eliminate leakages in suspension preheater by regular monitoring

Optimize primary air to kiln

Optimize kiln feed conveying air if any

Optimize kiln solid fuel conveying air if any

Optimize kiln shell cooling fans operation by interlocking with kiln shell scanner

KILN & COOLER

Initiate secondary firing in SP kilns

Ensure good compartment sealing

Reduce material leakages to avoid rehandling and loss

Install soft starters for clinker breaker

Improve solid fuel yard stacking to avoid carpet loss

KILN & COOLER

Increase coal mill output by

Optimizing fineness

Optimizing grinding media load

Installation of pre – crusher

Connect grate cooler vent to coal mill for drying

Avoid idle running of coal conveyer & crusher

Maintain higher residue for precalciner firing

KILN & COOLER

Water spraying on the clinker at cooler outlet (temperature > 90C, consumes more grinding energy)

Optimize cement grinding fineness

Avoid idle running of clinker conveyer & dust collector fan

Avoid idle running of cement silo exhaust fans

Optimize water spray compressor capacity

Optimize packing compressor capacity

CEMENT GRIDING, STORAGE & PACKING

Eliminate compressed air leakage by a vigorous maintenance programme

Install compressed air traps for receivers

Minimize compressor discharge pressure

Regularize frequency of cleaning of filters by measuring filter pressure drop. Maximum pressure drop across < 25mm WG.

COMPRESSOR & COMPRESSED AIR SYSTEM

Avoid unnecessary lighting during day time

Install photocell for automatic switching off

Avoid idle running of motors

Convert delta to star connection for motors loaded below 50% of full load (for occasional peak load provide automatic star / delta convertor)

ELECTRICAL SYSTEM

Use of polyester insulated copper chokes in place of conventional chokes

Operate lighting system at lower voltage ( say 360V in 3 phase)

Provide interlock for electric motor to avoid idle running

ELECTRICAL SYSTEM

Increase engine jacket temperature (max 85C) or as per engine specification

Stop cooling tower fans & cooling water circulation when not necessary

DG SETS

medium TERM MEASURES

Reduction up to 10% of energy bill by involve medium investment.

Energy Conservation Measures in Cement Industry

Install adjustable lifters in case of double chamber ball mill

Install variable louvre system for roller mill

RAW MILL GRINDING & STORAGE

Install CO & O2 analyser in kiln for monitoring

Maintain proper kiln seal to avoid false air infiltration

Install of coal weigh feeder at kiln firing and calciner firing

Use of lignite in place of coal

KILN & COOLER

Minimize kiln radiation losses by better refractory lining

Utilize cooler / cooler vent air as primary air

Install multichannel burners

Install water spray in cooler to minimize fan power consumption

KILN & COOLER

Minimize coal mill vent by

Reducing & regulating air vent

Installation of bag filter / ESP in the vent line

Use coal fired furnace instead of oil fired furnace for coal drying

COAL YARD & COAL MILL

Install belt conveyor / screw conveyor / bucket elevator system instead of pneumatic conveying

Storing of clinker for 7 – 10 days for seasoning of clinker

Install adjustable lifters

Utilize grinding aids

CEMENT GRINDING, STORAGE & PACKING

Cool compressed inlet air

Take compressor suction from outside the compressor house

Automatic loading / unloading of compressors and installation of auto start / stop sequence

Replace multiple small units with single large units

COMPRESSORS & COMPRESSED AIR SYSTEM

Use energy efficient lighting

Distribute load on transformer network

Improve power factor

Individual compensation

Group compensation

Centralized compensation

ELECTRICAL SYSTEM

Improve load factor

Install demand controller for maximum utilization of demand

Replace oversized motors

Replace old in-efficient motors with energy efficient motors

Use variable frequency drives for low / partial loads

ELECTRICAL SYSTEM

Install energy saver in fluorescent lighting circuit

Optimize height of lighting fixtures

Use servo stabilizer in lighting circuits

Replace conventional fluorescent tubes (40W) with slim tubes (36W)

ELECTRICAL SYSTEM

Increase loading on DG sets (max 90%)

Install turbocharger

Take turbocharger air inlet from outside engine room

Install oil flow meter & monitor

Install waste heat recovery system in DG set

DG SETS

LONG TERM MEASURES

Another 10% saving potential (average) is available by Implementing some of the long term measures

Energy Conservation Measures in Cement Industry

Install surface mining equipment

MINES

Install vertical roller mill in place of ball mill

Install belt & bucket elevator in place of pneumatic conveying

Install pre-crusher before raw mill

Install on-line X-ray analyser for raw meal

Install slip power recovery system / VFD for raw mill vent fan / ESP fan

Install high efficiency separators

Install continuous blending silo

RAW MILL GRINDING, STORAGE

Utilize waste tyre, rice husk, groundnut shell & urban waste in precalciner

Install electrostatic precipitator/bag filter for maximum dust recovery and minimum energy consumption

Conversion from pneumatic conveying of kiln feed to mechanical mode

Insulate preheater ducts internally by installing calcium silicate blocks followed by insulating bricks and refractory

KILN & COOLER

Install waste heat recovery system for preheater exhaust

Install waste heat boiler in cooler vent & run steam turbine

Modify internal drag chain system to external drag chain system to reduce break down hours

Install high efficiency coolers

KILN & COOLER

Install pre-crusher / roll press before ball mill

Install vertical roller mills for cement grinding

CEMENT GRINDING, STORAGE & PACKING

Install slip power recovery system for controlling speed for larger size slip ring motor

Install multi-speed motor

Optimize operating voltage level of motor for lightly loaded motors

Increase cable size / run additional cable to reduce distribution losses

ELECTRICAL SYSTEM

Use cheaper fuel for high capacity DG sets

Replace multiple small size DG sets with bigger DG sets

DG SETS

THANK YOU GENTLEMAN