CFD-DEM modeling of gas-solid flow and heat transfer in a FINEX melter&gasifier

Abstract

The blast furnace is the traditional ironmaking process and the most important technology to produce the liquid iron. However, as the natural resource has been rapidly depleted and the awareness of environmental protection has risen, new ironmaking technologies were developed in the last two decades. FINEX, the smelting reduction process, is one of the promising technologies that could solve these problems. Based on fluidized bed reducing technologies, fine ore can be directly used in FINEX process rather than cokes or sinter which leads to the reduction of the costs and adverse effect on environment caused by pellets or sinter preparation. To improve the FINEX technology, the multiphase flow in the Melter&Gasifier needs to be recognized. Mathematical modeling is an efficient way to achieve this especially the coupling approach of discrete particle simulation (DEM) and computational fluid dynamics (CFD). Gas-solid flow and heat transfer phenomenon were investigated at a microscopic level by CFD-DEM. The results reveal how variables like particles charging angles, solid flow rate, gas flow rate and particles properties influence particle flow patterns. Microscopic information such as individual particle velocity, porosity, coordination number and force structure acquired from the simulation process is crucial for us to understand the mechanism of particle flow patterns.