PRINCIPLES OF IMPROVING HEAT TRANSFER WITH AN EXTREMELY COARSE MIXTURE IN A KILN

Abstract

Experimental and thermal proofs of the advantages of using an extremely coarse raw material mixture (90 microns 50% residue on a sieve) over conventional fine-ground (90 microns 14% residue on a sieve) raw material mixture in the production of cement clinker are presented.

As a result of increasing the bulk density of an extremely coarse mixture to 1200-1400 g/ l, its thermal conductivity increases and the rolling process in a rotating furnace is significantly intensified. This causes intensive renewal and an increase in the surface of the fired layer to the sintering zone. Therefore, heat transfer and the number of reaction contact points increases. The higher weight of a liter of extremely coarse mixture makes it possible, with higher productivity, to reduce the degree of filling of the furnaces to an optimal value of 13% and significantly stabilize the operation of the furnace at an increased peripheral speed. All this makes it possible to increase the productivity of the furnace by 30-40% and reduce fuel consumption by up to 15%.