Abstract
Lowering of gas temperature at center of upper shaft was observed by decreasing sinter ratio in Mizushima No. 4 blast furnace and the stable operation was disturbed.
The burden distribution in case of the low gas temperature at center has been studied through quantitative analysis of the furnace operation data and model experiments. The ore layer collapse during ore charging was observed by the scale model experiments. The ore layer collapse could be treated quantitatively by use of a simulation model adopting a theory on the stability of the piled layer. The stability of ore layer was discussed by the model study in terms of operation variables, such as ore diameter, throat gas velocity and bell stroke. The results revealed that decrease in bell stroke and bell descending velocity could effectively prevent the burden distribution in case of low gas temperature at center.
