Influence of Coke Layer Collapse Phenomenon on Burden Distribution at the Top of Blast Furnace

Abstract

The phenomenon of coke layer-collapse occurs when ore is dumped onto the inclined coke bed. The coke layer-collapse causes to change the distribution of ore and coke layer thickness in the radial direction. Therefore, the effects of charging condition and distribution of gas flow and burden descending velocity on the coke layer-collapse have been studied by using a reduced-size experimental apparatus in which the conditions of gas flow and burden descent have been simulated to those of actual furnace top.
The experimental results show that the magnitude of coke layer-collapse is mainly dominated by the charging mode, and the state of coke stacking in the central region after the collapse is also influenced by gas flow and descending velocity distribution. The changes in inclination angle of coke layer and coke movement accompanied by the collapse have been investigated. It is confirmed from these investigations, that the scale of coke layer-collapse depends on the stability of inclined coke layer. On the base of these findings, a mathematical model for quantitative evaluation of coke layer-collapse is developed by introducing the theory of soil mechanics. The calculated results by the model consist with experimental results for coke layer-collapse.