Abstract
The mechanism of solids mixing is considered as a vital factor to the metal smelting, catalytic cracking and combustion performance in the multi-particle field. In this paper, the computational fluid dynamics coupling discrete element method (CFD-DEM) approach was employed to simulate the binary particles movement and mixing within a baffle type internal circulating fluidized bed (ICFB). Moreover, the mixing behaviors of binary particles were experimentally validated in the macroscopic scale. Polyethylene particles were used as bed material, and glass beads and rubber particles were chosen as tracers. The above two research methods are to add tracer particles after achieving the circulating movement of polyethylene particles around the vertical plate. The mixing behaviors were investigated in terms of flow patterns, solid circulating mass flux, and mixing index. Moreover, the effect of inlet gas velocity ratio on mixing also conducted in the current research. The results indicate that there is an optimal velocity value of fast and low inlet gas velocity to achieve the solid circulation mass flux. The particle density has a significant influence on the mixing degree and rate of the binary particles. Besides, from the simulation of the effect of four groups of inlet gas velocity on mixing index with glass beads as tracer particles, it is found that more particles can be entrained into the cycle mixing movement with the increasing gas velocity. These findings could be helpful for the design and optimization of the novel fluidized reactors.
