2020 年 60 巻 7 号 p. 1560-1569
The void structure in the deforming packed bed like cohesive zone of blast furnace was discussed. The examined packed bed consisted of mono-dispersed spherical particles and was numerically prepared by using the discrete element method. From the obtained packing particle structure, the characteristics of the void space, namely voidage, surface area, hydraulic radius, flow path network structure, width and length of the flow path, were extracted. The actual hydraulic radius deviated from the one calculated from the bed shrinkage with the bed deformation, and this deviation resulted the large difference in the pressure drop in the packed bed. The flow path (void) network was successfully extracted from the particle packing structure. Additionally, distributions of the path width and length were obtained. The choking of flow path with bed shrinkage can be quantitatively visualized. In the softening ore particle bed with nut coke mixing, the flow path structures around ore and nut coke particles showed different behavior. With the obtained characteristics of the void structure, the variations of the pressure drops in the reduction test under loading and in the softening ore layer with coke mixing can be explained.
