Numerical analysis of electrostatic effects during powder deposition using DEM/CFD

Electrostatic interaction can play a significant role in pharmaceutical powder processing. In this study, a coupled discrete element method and computational fluid dynamics (DEM/CFD) model was developed with an implementation of electrostatic interactions. Using the developed DEM/CFD, deposition processes of monodisperse particles with and without electric charges were simulated. It was found that the electrostatics significantly affects the deposition behaviour of particles. In particular, it was revealed that for charged particles three distinctive processes were identified during deposition: 1) clustering; 2) impact fragmentation; and 3) packing. It was also observed that charged particles could stick with the vessel walls due to the presence of electrostatics.