GAS-DISTRIBUTION IN GRANULAR ZONE OF BLAST-FURNACE - ROOM-TEMPERATUREMODEL STUDIES

Blast furnace productivity is governed to a large extent by the aerody namics of gas flow from the tuyeres to the top of the furnace. In this context, the gas permeability in the granular zone and in the lower p art of the furnace is quite important. Permeability studies carried ou t in the R&D Division of Tata Steel have shown that improving the mean size of the burden materials, decreasing the interfacial resistance b etween the charge layers, and minimising the fines content in the inpu ts can help improve the stack permeability. Control of permeability in the radial direction in the stack is possible by improved burden dist ribution. Optimum conditions with regard to burden distribution, charg e proportion, and particle size range have been identified for decreas ing the pressure drop in the shaft to 0.6-0.7 kPa m(-1). It is envisag ed that, if the pressure drop occurring in the granular zone of a blas t furnace can be minimised, it will ultimately reduce the total pressu re drop, resulting in improved air acceptance and, hence, better furna ce productivity. (C) 1996 The Institute of Materials.