DEM simulation on particle mixing in dry and wet particles spouted bed

In this paper, the mixing characteristics of the dry and wet particles in a rectangular spouted bed are simulated using a three-dimensional discrete element method (DEM). In particular, the influence of turbulence and liquid bridge force is investigated using the standard k-ε two-equation model and the Mikami model. The Ashton mixing index is adopted to evaluate the dynamic mixing process of the particle system. The geometry of the simulated bed is the same as that of the experimental bed by Liu et al. [G. Q. Liu, S. Q. Li, X. L. Zhao, Q. Yao. Chem. Eng. Sci. 63 (2008) 1131–1141]. The effect of the spouting gas velocity on the mixing process is discussed for the mixing of dry particles (without the liquid bridge force), while the effect of the moisture content is discussed for the mixing of wet particles (with the liquid bridge force).

Graphical abstractThe mixing behavior of dry and wet particles in a rectangular spouted bed is simulated in three-dimensions. For dry particles, the mixing rate of spouted bed increases with the increase of spouting gas velocity. For wet particles, the mixing rate of spouted bed decreases with the increase of moisture content.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► We investigate the mixing mechanism in dry and wet particles spouted bed via DEM. ► Increasing gas velocity will increase the mixing rate of dry particles spouted bed. ► Increasing moisture content will decrease the mixing rate of spouted bed.