  Reduced iron-bearing materials start softening in the cohesive zone of a
blast furnace due to the high temperature and the weight of the burden above.
Softening process causes a reduction of void space between particles. As a
result, the pressure drop and gas flow change remarkably in this particular
zone. As a consequence, it has a significant influence on the performance of a
blast furnace and is needed to be fully characterized. For this reason, the gas
rheology along with the deformation of the particles and the heat transfer
between particle-particle and particle-gas should be adequately described. In
this paper, the eXtended Discrete Element Method (XDEM), as a CFD-DEM approach
coupled with the heat transfer, is applied to model complex gas- solid flow
during the softening process of pre-reduced iron ore pellets in an Experimental
Blast Furnace (EBF). The particle deformation, displacement, temperature, and
gas pressure drop and flow under conditions relevant to the EBF operations are
examined. Moreover, to accurately capture the high gas velocity inlet, a
dual-grid multi-scale approach is applied. The approach and findings are
helpful to understand the effect of the softening process on the pressure drop
and gas flow in the cohesive zone of the blast furnace.

Computational Engineering, Finance, and Science