Numerical study of the influence of the powder and pipe properties on electrical charging during pneumatic conveying

During pneumatic transport, powders often experience the build-up of electrostatic charge due to collisions of the particles with the pipe. Since this can lead to hazardous spark discharges with unwanted implications, such as accidental explosions, there is a strong interest in exploring various options to limit this electrification process. In this paper we present the results of numerical simulations that we performed in order to evaluate the influence of the material properties of the powder and pipe, respectively, on this process. In our study, the turbulent flow of the carrier gaseous phase was treated numerically via Large Eddy Simulations while the particles were tracked individually in Lagrangian framework. Four-way coupling between the powder and the gaseous phase was also assumed. Our numerical simulations predicted that the particle Poisson ratio and Young's modulus, its electrical resistivity, as well as the permittivity represent promising measures to control the charge of the powder. More specifically, an increase of each of these quantities by 50% may lead to a decrease of the powder charge of up to 40%. (C) 2017 Elsevier B.V. All rights reserved.