Mechanism of enhancement of particle motion in gas-fluidized beds with coarse particles by adding liquid

Abstract

DEM (Discrete Element Method) has been employed by many researchers to simulate the motion of granular particles. Additional forces, such as the fluid drag force, van der Waals force, liquid bridge force, electrostatic force, can be introduced easily in the DEM simulation. The DEM simulation has been combined with the CFD (Computational Fluid Dynamics) technique, and the DEM-CFD simulation has been applied to the fluidized bed by many researchers. Some researchers have taken account of the cohesive forces to simulate the small particles, such as A-particles or C-particles in the Geldart's classification. Recently, some research groups reported that the addition of the liquid in the fluidized bed with coarse particles enhances the particle motion. However, the mechanism is not understood yet. In the present study, a liquid transportation model is introduced in the DEM simulation to understand the mechanism of the enhancement of the particle motion in the fluidized bed by adding liquid.