Abstract
Modified Siemens is a main technology in polycrystalline silicon production unit. Their pipes often occur serious droplet particle erosion in the hydrogenation process that causes silicon tetrachloride reaction to trichlorosilane. Droplet particle erosion easily causes hazardous medium leakages, even leading to fire and explosion phenomena and economic losses. A droplet-particle erosion phenomenon happened in connecting pipe between the static mixer and the silicon tetrachloride evaporator of the polycrystalline silicon production unit. This work aimed to accurately analyze the erosion phenomenon position formation caused by simulation. The erosion phenomenon was predicted with the dense discrete particle model (DDPM), coupling into energy-minimization multi-scale (EMMS) drag model to improve the accuracy of non-uniform gas-liquid flow distribution. Comparison with simulation dates is conducted regarding the gas-droplet drag model, droplet wall specularity coefficient, atomized droplet size, and hydrogen volume fraction. The results indicated that the simulation approach with drag modified and suitable parameters selected has a good agreement with industrial phenomenon data. The different atomized droplet particle sizes directly affect the erosion location, the predicted position with 100μm droplet size is in accord with actual phenomena. The flow rate with the increase of hydrogen volume fraction also affects the erosion location and rate. In addition, the erosion phenomenon is due to poor atomization and a high gas-liquid flow rate.
