Investigation on the Profile of Softening-Melting Zone in the Dissected Blast Furnace

Abstract

In order to clarify the function of softening-melting zone in a blast furnace, a mathematical model, by which the gas volume rate distribution through coke slits between softening-melting layers above “roots” can be calculated, is devised. Calculated results with Hirohata No. 1 blast furnace show that the greater part of bosh gas flow through the coke slits in lower softening-melting zone, and that the softening and melting-down volume of every softening-melting layer is proportional to the coke slit gas volume rate just under that layer.
It is considered that the irregular shape of “root” softening-melting layers in Hirohata No. 1 blast furnace was mainly caused by the difference of blast volume rate at every tuyere.
And also, from the relationship among the slit gas distribution, pressure drop and position of top softening-melting layer and inner or outer sides of softening-melting zone, which is calculated by the above mentioned mathematical model, a desirable profile of softening-melting zone is proposed.