Analysis of the relationship between the transferred charge signal and the particle collision in pneumatic transport based on CFD-DEM

Abstract

Abstract The measurement of gas–solid two-phase flow based on the transferred charge method takes advantage of the charge transferred phenomenon generated during the contact between particles and electrodes, which is of great significance to the measurement of gas–solid flow parameters. However, the charge transfer mechanism is very complex, so far there is no mature theoretical model to explain it completely. By using the computational fluid dynamics-discrete element model (CFD-DEM) coupling simulation method, the particle collision model is introduced into the process of flow field simulation. In the CFD-DEM coupling simulation, the modified gas–solid rolling force model and the particle tangential stiffness model are introduced in this paper, and the relationship between the particle-electrode collision and the superficial gas velocity vg , the particle mass flow rate Ms is simulated. In the gas–solid two-phase flow experiment, the accuracy of the simulation model is verified by the experimental data of pressure drop signals. The distribution factor Ti of the transferred charge signal for the array electrostatic sensor is proposed. When Ms is fixed, the transferred charge signal of the particles increases exponentially with vg . When vg is fixed, the transferred charge signal of the particle increases in proportion to Ms . With the increase of vg . or Ms , the Ti of No. 9 electrode at the bottom of the pipe is the largest. Ti can help to characterize the flow parameters of pneumatic conveying.