Simulation of flow behavior of liquid and particles in a liquid–solid fluidized bed

Flow behavior of liquid and solid phases is simulated by means of DEM-CFD in a liquid–solid fluidized bed. The lubrication force is considered. A detailed description of the model equations used has been presented. The distributions of velocity and volume fraction are predicted at the different superficial liquid velocities, liquid viscosity and solids densities in the bed. The granular temperature is computed from simulated particle velocity. Predicted solid axial velocities are in agreement with experiments. Simulations indicate that axial velocities of particles increase with the increase in the superficial liquid velocity. The bed expansion height is increased with an increase of superficial liquid velocity and liquid viscosity and decreases with the increase of particle density. The lubrication force reduces granular temperature in the liquid–solid fluidized beds.

Graphical AbstractOne of the main effects on motion of particles is the lubrication force which opposes the contact between particles that approach with small relative velocity. Without lubrication force, many-particle structures form and survive for long times. When the additional lubrication force is incorporated into the equation of motion, the instantaneous distributions of particles are more uniform than without lubrication force.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► DEM-CDF is introduced into the numerical simulation of liquid–solid two-phase flow. ► The impact of the lubrication force and virtual mass force is considered. ► Both particles and liquid flow up in the center, particles flow down near the walls. ► The solid volume fraction is high near the inlet, and low at the bed surface. ► The lubrication force reduces granular temperature in the bed.