Three-dimensional numerical study of combustion of char in raceway of COREX melter/gasifier

Abstract

A three-dimensional numerical model was used to simulate the gas–char two phase flow and combustion characteristics in the raceway of a COREX melter/gasifier. The flow was depicted using Euler–Lagrangian models, and a kinetic/diffusion limited rate model was used to simulate char oxidation and the gasification reaction. The models were used to predict the main features of the complicated gas–solid flow and combustion. The gas temperature, velocity distribution in the raceway, and gas species distribution were also obtained. The results show that large scale recirculation occurred in the raceway. Furthermore, the effects of oxygen velocity, purity and temperature on the gas temperature distribution in the raceway were studied. The findings provide a reliable theoretical basis for optimisation of operating parameters and further research of the COREX process.