CFD-DEM-IBM simulation of particle drying processes in gas-fluidized beds

Abstract

A great deal of industrial processes involves drying processes that removes water from the surface and interior of particles, where knowing the flow behavior, mass and heat transfer is crucial for proper design and optimization of industrial dryers. This work developed a CFD-DEM method for the simulation of particle drying processes, where the immersed boundary method (IBM) was used to handle the no-slip boundary condition of gas phase at the wall of complex geometries. The model was validated by comparing the numerical results to the experimental data of particle moisture and gas (particle) temperature in the dense bubbling bed and dilute pneumatic conveying bed, respectively. Compared with the experimental results, the maximum relative errors of outlet gas temperature, particle temperature and water content in the pneumatic conveying bed are 2.2%,2.2% and 7.9%, respectively. It was also found that considering the effect of Stefan flow on the drag correction did not affect the studied particle drying processes. Present study proved that CFD-DEM-IBM method is powerful for simulating the fluid flow, mass and heat transfer in gas-fluidized beds.