Modeling of chemical vapor deposition of silane for silicon production in a spouted bed via Discrete Element Method coupled with Eulerian model

A CFD-DEM coupling model was applied to the silicon production by silane chemical vapor deposition in a spouted bed to investigate local phase movements, mass transfer, heat transfer and the deposition rate of silicon. Silicon particle growth by heterogeneous deposition on the seed particle and fines formation in the gas phase were included. In addition, the scavenging effect was also considered in the particle growth mechanism. The spouted bed has advantages to promote heterogeneous deposition time due to a larger solid-holdup and higher gas residence time in the annulus region. Furthermore, the effects of operating conditions—i.e., inlet gas temperature, silane composition and gas velocity—on the reactor performance were investigated in detail, and some guidelines are provided for the choice of operating conditions. Verification of solid movement results with the experiments data and correlations show good agreement. In addition, the axial profile of bed voidage agrees well with correlation.