Regression Analysis of the Heat Balance Thickness of a Blast Furnace Hearth Lining

The reasonable structure and operation of a hearth can reduce the probability of serious depression and erosion of the lining of a blast furnace (BF). The temperature of the hearth lining is high inside and low outside. Theoretically, there is a heat balance state in the hearth. A three-dimensional computational fluid dynamics (CFD) calculation model that can simulate the theoretical heat balance state of the lining for different hearth design structures and operating parameters was established in this paper. Based on the calculation model, the response surface method was used to study the regression relationship between different factors and the thickness of the lining. In addition, the sensitivity of each factor to the thickness in a state of heat balance was evaluated. The analysis results showed that the blast furnace volume utilization factor and tapping temperature had a greater impact on the theoretical heat balance thickness of the hearth lining. These two factors had an obvious interaction. With the increase in the blast furnace volume utilization factor, the sensitivity of the heat balance thickness to the tapping temperature gradually decreased. The cooling water flow rate had a small effect on the heat balance thickness. The theoretical basis for the optimization of the hearth structure and the improvement of the operation method was provided in this paper.