Computational analysis of triboelectrification due to aerodynamic powder dispersion

Triboelectric charging can strongly influence bulk powder flow behaviour, and hence its characterization is of great interest for safe manufacturing operations. In a recent development, the use of an aerodynamic disperser, employing a pressure pulse to disperse a small powder quantity, shows a great potential for inducing triboelectric charge transfer. We analyse this process by coupled Discrete Element Method and Computational Fluid Dynamics (DEM-CFD) simulations, incorporating triboelectric charge transfer. The simulations are based on property data of glass ballotini as model particles, together with those of α-lactose monohydrate (α-LM) and aspirin, as powders of practical interest. The characteristics of particle-particle and particle-wall collisions are analysed in detail. The analysis shows that pharmaceutical particles charge significantly more than glass ballotini. The charge-to-surface area ratio is remarkably constant and close to its equilibrium value for each test material. Overall, the analysis provides a great insight on the triboelectric charging by aerodynamic dispersion.