Effect of centre coke charging on shape of deadman in blast furnace

The mechanism of deadman renewal by centre coke charging was investigated using a 1 : 15 scale model of POSCO's Pohang No. 3 blast furnace. The deadman shape in the two-dimensional model could be predicted on the basis of the assumption of an active state in the packed bed. The deadman height depended mainly on the amount of fine powder accumulated in the deadman because the internal and wall friction angles of coke varied according to the amount of fine powder. The deadman was renewed differently according to the ratio of centre coke charging width r(c) to throat radius R, the critical value of which was found to be 0.12. Test operation for centre coke charging under r(c)/R > 0.12 conditions resulted in an improvement in central gas flow and a reduction in heat loss. The renewal period of the deadman was estimated to be about two weeks in an actual blast furnace. IS/1350 (C) 1998 The Institute of Materials.