Numerical simulation of the flow and erosion behavior of exhaust gas and particles in polysilicon reduction furnace

Abstract

In order to study the flow and erosion behavior of gas-solid exhaust in the polysilicon reduction furnace, the flow characteristics of exhaust gas and silicon particles were analyzed. The flow model and erosion model of exhaust gas and silicon particles were established based on the gas-solid flow theory and the erosion theory. The erosion and wear behavior of the gas-solid mixture in the flow passage pipeline were studied by numerical simulation. The results show that the wear and erosion from Nos. 1 to 8 regions at the bottom of the ring were caused by silicon particles colliding with high angle. The wear and erosion of 2 regions from Nos. 9 to 10 at the outside of the up azimuth on both sides of loop pipe outlets, 4 regions from Nos. 11 to 14 on the upper and lower wall of single furnace main channel were severely affected wear regions, which is caused by silicon particles with low angle and high velocity. Through comparative analysis, the erosion of upper wall of single furnace main channel is most serious. Increased gas velocity, particle concentration and particle size will exacerbate the erosion and wear rate of the pipeline in polysilicon reduction furnace, but the distribution and development of severe wear zone would not be affected significantly.