The spatio-temporal evolution of tribo-electric charge transfer during the pneumatic conveying of powders: Modelling and experimental validation

► To model spatio-temporal evolution of particles charge during pneumatic conveying. ► Both analytical solutions for simplified cases and numerical methods are developed. ► Excess or lack of chargeability of wall is a key parameter for charge transfer. ► At excess ratios greater than one, the particle charge is not limited by the walls charge. ► The model permits to predict the system's behaviour for large scales of time and space.