Investigating the effect of particle shape on the charging process in melter gasifiers in COREX

This work conducted numerical simulations based on the discrete element method (DEM) and computational fluid dynamics (CFD) to study the effect of particle shape on burden distribution and gas flow distribution in the COREX melter gasifier. The non-spherical particles were approximated by a multi-sphere approach in which overlapping spheres were glued together to represent particle shape. The model was firstly validated by comparing the effect of particle shape on packing characteristics with previous work. With increasing of particle non-convexity shape factor, the packing density decreased and the mean coordination number increased. The model was then extended to study the charging process in a melter gasifier. The mixing of the direct reduced iron (DRI) with non-spherical coke particles had a significant effect on pressure drop and ore-to-coke mass ratio. The pressure of the non-spherical coke burden bed was significantly larger and the ore-to-coke mass ratio was more comparable to that of the experiments. With increasing non-spherical DRI mass fraction, the particles were distributed more evenly in the circumferential direction, but pressure drop also increased. The findings facilitate a better understanding of the relation of particle shape to the burden distribution in the COREX melter gasifiers. (C) 2019 Elsevier B.V. All rights reserved.