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

The mechanism of deadman renewal by centre coke charging was investigated u sing a 1 : 15 scale model of POSCO's Pohang No. 3 blast furnace. The deadma n 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 depend ed mainly on the amount of fine powder accumulated in the deadman because t he 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 unde r r(c)/R > 0.12 conditions resulted in an improvement in central gas flow a nd a reduction in heat loss. The renewal period of the deadman was estimate d to be about two weeks in an actual blast furnace. IS/1350 (C) 1998 The In stitute of Materials.