Some aspects of improvement in the thermal efficiency of coal fired down draft kilns

The global crisis of fuel has led the industries to shift over from the old conventional furnaces consuming high volume of fuel to the kilns of new design having high thermal efficiency. In the advanced countries, conventional furnaces are replaced by new generation kilns having very light structures and very high thermal efficiency, provided with super insulation and efficient equipment like low fuel consuming burners, blowers etc. R & D work for fuel economy is a continuous process for fuel saving. The developments might be in terms of application of better insulation, equipment, refractories or change over to new design of kilns. Our country also faces the same problem of fuel crisis as oil is mostly an imported item. Natural gas is not abundant and the quality and availability of coal is uncertain. Thus the conversion of the existing thermally inefficient conventional furnaces to energy saving kilns for fuel economy has assumed prime importance. These points are discussed in this article