Numerical simulations and validation of gas–solid flows in a fluidized‐bed roaster based on the CFD‐DPM model

Abstract

In view of the complex gas–solid flow characteristics in a fluidized‐bed roaster, the discrete phase model (DPM) provided by ANSYS software was used to numerically analyze the model using a coupled algorithm. The asymmetric flow phenomenon in the transition section at the top of the furnace was found to be unfavourable to the gas–solid flow, and an inverted U‐shaped furnace structure was proposed to optimize the transition section at the top of the furnace. A large cold experimental setup was built to verify the model. The results showed that the air velocity is mainly in the axial upward direction; under the action of the gas, the solid particles and the air velocity are basically in the same direction. The main furnace and subfurnace connection section changes the movement of the gas–solid mixture, and its unreasonable structure leads to the asymmetric flow phenomenon of the gas–solid fluid at the top of the furnace. Compared with the previous furnace structure, the uniformity of gas–solid flow in the optimized ‘inverted U‐shaped’ structure has been significantly improved. The cold experimental results are in good agreement with the numerical simulation results, which verifies the accuracy of the proposed model.