TFM-KTGF Simulation of Gas-Solid Fluid Dynamics and Bubble Size Distribution in A Silicon CVD Fluidized Bed Reactor

Fluidized bed reactor for silane deposition is an important technology for solar-grade silicon production. The gas-solid fluid dynamics and gas bubble size distribution are key factors influencing the purification and density of the crystalline particles. In this paper, the TFM-KTGF two-fluid model coded in Ansys fluent platform was employed in the simulation of the gas-solid fluid dynamics in a silicon CVD(Chemical Vapor Deposition) fluidized bed reactor. A 0.5 m diameter cylindrical silicon fluidized bed was simulated with computational grids of 200 times particle size. The Matlab image processing toolbox was used for the post-processing of the simulation data and to obtain the bubble size distributions. The bubble size distributions calculated by classical Gidaspow drag force model and a literature reported sub grid scale model(SGS) were compared. The results show that the change of the average bubble size distribution along the bed height predicted by SGS model is close to that by Mori-Wen's equation, with a maximum deviation of bubble size of 12.6%, which is smaller than 21.4% obtained from Gidaspow model. The type of drag force model showed relatively strong impact on the distribution of babble size. These results paved a solid foundation for further quantitative analysis of hot model silicon-CVD reactors.