Cement and Energy

pores is provided at the cold face end, wh.ile the hot face end is kept densely packed. Th.is configuration reinforces the insulation and gives the lining a low degree of thermal conductivity, difficult to achieve with conventional bricks. Saving in Maintenance Costs Conventional insulation bricks. composite bricks, and other low density insulating bricks get eroded easily, when used in the calcination zone. They do not last long under conditions of intense heat, chemical attack and constant rotary motion. The new clog bricks, on the other hand, last longer owing to their ideal compressive strength and better resistance to chemical attack and abrasion. Once installed, they do-·not have to be replaced for 4- 5 years. Improved Corrosion Resistance The contact area being only of the order of 30% and the voids being large and close to the surface, the penetration of aggressive agents like Cl /S0 3 I Alkalis/F to the shell surface is inhibited thereby reducing the corrosion effect. This in tum will improve shell life. 1~198~ 4 :~ tLD m! 0 : 0 ll) : ~ .... ; .. - . - .. - . - .. - . T .. -· . - .. - . - .. -r~ 1~ 69 ~ ~ k--20 r- 1984 4 :~ tom:-~ · o : 1 .L - r-~1 Courte.ry : Dalmia Ceme/11 (Bharat) Ltd. COGENERATION OF POWER UTILISING WASTE HEAT IN CEMENT MANUFACTURE INTRODUCTION C ement industry is a highly energy intensive industry utilising both coal and electricity. Cogeneration of power utilising waste heat is an attracti ve proposition for cement plants forminimising electricity requirement from the grid and thus reducing the load on coal/gas/oil based thermal power plants, thereby reducing greenhouse gas emissions, in tum. Cogeneration assumes greater significance in the Indian context in view of the power shortages in many states which results in production losses and hi gher energy consumption apart from increased dust losses due to unstable operation. The cement industry can mitigate the problemof power shortage and poor quality of power to a considerable 2 ---