Numerical investigation of the particle flow behaviors in a fluidized-bed drum by CFD-DEM

Abstract

The fluidized-bed drum technology involving the combination of a fluidized bed and a rotating drum is used for the granulation and coating of particles, which has been successfully applied in industry. Nevertheless, there should be few published fundamental studies for exploring the particle flow behaviors in a fluidized-bed drum, particularly in the particle level. Consequently, the particle-scale DEM (Discrete Element Method) was coupled with CFD (Computational Fluid Dynamics) in this work to simulate the particle-fluid flow system in a fluidized-bed drum. The experiments in a small horizontal fluidized-bed drum were also carried out to validate the accuracy of our CFD-DEM model. Subsequently, the particle flows in a large inclined fluidized-bed drum were simulated by CFD-DEM, and the relatively comprehensive investigation for the influences of operational conditions (including the gas inlet velocity, drum rotation speed, drum inclination angle and fluidized-bed inclination angle) on the particle flow behaviors (e.g., the particle holdup, particle velocity and particle residence time) was carried out. According to the simulation results, the particle flow behaviors would be significantly affected by these operational conditions. However, increasing the gas inlet velocity could weaken the effects of drum rotation speed, drum inclination angle and fluidized-bed inclination angle.