Analysis of Softening-Melting Behavior of Sinters and Their Packed Bed Considering Internal Structure Particles - Part 2: Direct Evaluation of Packed Bed Deformation and Gas Permeability

This study extended a dynamic model of the softening and melting behavior of sinter in the cohesive zone of a blast furnace to clarify the deformation behavior of a packed bed in relation to the internal morphology of a two-layer structure. This structure comprises a solid–liquid coexisting oxide phase (core) and porous iron (shell), with internal voids in the sinter particles that change owing to gas reduction. The detailed morphology of the sinter was obtained through industrial X-ray computed tomography (CT), and the structural changes and permeability of the packed bed were estimated through gas flow analysis. The results demonstrated that changes in the internal structure led to increased shrinkage as the degree of reduction and shell elastic force decreased. Even when the rotational and translational motions of the sinter particles were excluded, significant linear deformation was observed in the horizontal and vertical directions, and 3D behavior occurred on a particle-by-particle basis. Permeability analysis quantified the pressure changes resulting from ore deformation and the resulting core outflow. The results revealed that gas flow channels narrowed and were blocked as the reduction rate and shell elasticity decreased. The advantage of this newly proposed procedure is its extension of convergence engineering simulation technology. This is valuable for further understanding the chemical and physical heterogeneity of ore particles in packed beds based on actual measurements.