Abstract Fluidized bed process preparing polysilicon granules is a method of great advantages for its lower energy consumption and higher efficiency. Internal Circulation Fluidized Bed (ICFB) can effectively prevent the deposition of silicon on the heating wall. Fluidization behaviors of wide size distribution particles in actual production process were investigated in this paper. The results showed that fluidization quality of wide range particles was much better than narrow ones. Segregating fluidization of wide size distribution particles was restrained in an ICFB for the circulation of particles. The solids holdup es, solids circulation rate Gs and bypassing fraction γRD and γDB in an ICFB were experimentally studied. When UD/Umf and UR/Umf were between 2.5~3.2 and 2.2~2.7, respectively, γRD was smaller than 4%. A results from an estimation showed the ICFB in this article can meet the need of heat supply and reduce the deposition on the heating wall.
