Modeling and Analysis of Heat Transfer in Deforming Packed Bed

Abstract

The cohesive zone of the blast furnace is one of the most important zones because it deeply relates to the furnace stability and efficiency. It is considered that the thickness of the cohesive zone increases with decreasing the reducing agent rate and increasing the usage of the low grade raw materials in future. The thickness of the cohesive zone should be decreased or permeability of the cohesive zone should be improved to keep the furnace stability and production efficiency. Heat transfer in the cohesive zone is a quite important issue to control the cohesive zone because it determines the temperature rise of this zone namely softening and melting rate of the burden materials. In this study, a mathematical simulation model for the fluid flow and heat transfer in the packed bed of the deforming particles was developed. This model combined the discrete element method for bed deformation and the computational fluid dynamics for the gas flow. Additionally, the inter-particle heat exchange in the deforming packed bed was newly formulated and linked with the discrete element analysis. This mathematical model successfully revealed the variation of the heat transfer mechanism with the deformation of the packed bed. The simulation results could give the useful information for designing the burden distribution under the low carbon and high low-grade material operation of the blast furnace.