Quantifying the Effect of Coke Layer Thickness on Permeability of the Cohesive Zone in the Blast Furnace by Using a New Simulator

摘要

Recently, low coke rate operation in blast furnaces has been required, because of rising the price of ironmaking coal. On the other hand, coke works as a spacer in a blast furnace, thus, low coke rate operation causes various problems, including deterioration of furnace permeability, channeling, and delay of a reduction reaction. Further, Ichida et al. studied the effect of the coke layer thickness on permeability at Muroran No. 2 blast furnace, and they confirmed that permeability deteriorated when the average lump coke layer thickness was less than 190 mm in the belly zone. This result shows that the coke layer thickness is an important factor for stable blast furnace operation, and indicates that there is a minimum coke layer thickness for maintaining stable operation. Nevertheless, the effect of the coke layer thickness on the permeability of a blast furnace had not been studied theoretically. Therefore, it is important to reveal the mechanism of the minimum coke layer thickness and clarify the minimum coke layer thickness.