Modified design and lining of tunnel kiln for Indian iron industry to improve furnace efficiency

In India, a large number of ceramicware manufacturers are actively engaged in small / medium sectors with production capacities varying from 500 to 1500 tons per annum. These units are largely located in northern and western India. Average oil consumption of these industries are in the range of 170-250 L.ton–1 of product. Initial study conducted in some of these industries reveals that there is large temperature gradient across the height of the kiln and excess oxygen in all zones. Kiln shell temperature also is very high in all of these kilns. Also, the insulation system of kiln car lining is very erratic and often leads to failure and consequent loss of production. Based on the findings, it was decided to incorporate changes in design concepts in some of the kilns and optimize temperature, pressure and combustion regimes of the furnaces. Implementation of all the modifications in two kilns has resulted in increase in productivity by 30-35% and reduction in specific fuel consumption by 15-20%