Cement and Energy

" 350 300 250 200 150 100 50 0 Lt906-87 I Pre· mod~rr11- SOliOn 1~3·9~ W1lh technotog1cal upgradat10n • Fuel consumption kg/T of clinker • Power consumptiOn Un1ts/T of cement [.994-95 1995·96 1996-97 1997-98 W1lh In-house major/minor modifications and operational improvement Fig I l'rogres.\il•t• Rl'rluction in Power and Fuel Consumption In August 1996. for capacity captive power generation 3x5 M\V DG sets were installed to achieve self– sufficiency m power and ensure un-interrupted operation of the plant. In November I 096, waste heat recovery system was commissioned to generate power by utilising the waste heat from the exhaust gases of the DG sets. Operational Measures/Minor Modifications Various changes in the operating practice and minor mod ifications in the plant have been incorporated for improving overall productivity and reducing energy consumptiOn in a phased manner from December 1995 onwards. fhe measures taken are highlighted below : • Modification in the tertiary ai r duct to draw air from ki ln hood instead of from cooler, which helped in reducing specific heat consumption by 24 kc:M/kg clinker. • Mi nimising. fa lse air entry into preheater, gas conditioning tower on a continuous monitoring basis helped reduce power consumption by 0.75 kWh/tonne of clinker. • Mod ificauon in feeding limestone to secondary crusher from ropeway unloading hopper by • providing belt conveyor system instead of push feeder system resulted in a nominal saving of 0.03 kWh/tonne of limestone handled. Widening of conveyor belts, enhancing speed of belt and modification in turbo air separater in raw mill to eliminate production constraints. • Installation of multi-channel Pillard burner in place of conventional burnet' in small kiln, which helped in reducing coal consumption by I%. • Installation of capacitors for improving the individual power factor for higher capacity motors. • Use of imported coal to improve overt:H~ performance of the ki ln. • Installation of ve rtical shaft impactor for stze reduction of clinker and optimisation of cement mill operation, which Jed to reduction of power consumption. Future Plans Since conservation of thermal and electrical energy is a continuing mission with the plant, the following important actions have been planned. • Replacement of small coal mills by additional vertical coal mill. • Use of thermal insulation bricks in the calcining zone of kiln. • Installation of high efficiency fans for waste gas fans. • Variable speed drive for cooler ESP and cooler fans. • Installation of fuzzy logic control system for optimisation of kiln operation. • Modification of tertiary air duct connection and preheaters to improve kiln operation. 3