A Computational Study on the Reduction Behavior of Iron Ore/Carbon Composite Pellets in Both Single and Multi-layer Bed Rotary Hearth Furnace

A phenomenological model for the reduction of iron ore/carbon composite pellets in a multi-layer bed rotary hearth furnace has been developed. A single pellet model has been scaled up to a multi-pellet layer version in a computationally efficient way. The multi-layer pellet bed has been conceived as single column of identical pellets in a rectangular enclosure, assuming symmetry of the pellet bed in horizontal direction. The column walls are considered opaque with respect to heat transfer but allow heat radiation to reach the pellet surface through multiple reflections from the wall. The time-temperature-transformation and time-temperature-chemical heat absorption contours are presented to provide a better understanding of the reduction process. Finally, the net heat flux and carbon monoxide generation, emerging from the multi-layer bed system has been generated, which may be used as source and sink terms for CFD simulations in the free board of the RHF.