Modeling and analysis of particle triboelectrification in pneumatic conveying

This paper presents a numerical study of the tribocharging process during pneumatic conveying using computational fluid dynamics (CFD) and the discrete element method (DEM). It simulates tribocharging by the condenser model, considering the frictional charge important to pneumatic conveying. The model is validated by comparing the simulation results with the specific charge measurements in the hopper and chute. Via the model, the cumulative charge and its effect on the performance of horizontal pneumatic conveying are quantified. A phase diagram is established to predict particle charging modes with respect to solid concentration and gas velocity. The flow characteristics are analyzed to understand charging phenomena. It shows that particle charge accumulation is critical for developing distinct particle patterns, such as particle ring, cluster, and plug. The plug flow causes rapid charge accumulation and significant fluctuations in particle flow rate and gas pressure, which can be mitigated under properly controlled operating conditions.