Electrostatics of granular flow in Pneumatic conveying systems

Abstract

In this study, the electrostatic charge phenomenon and their effects on granular flow behavior were studied in a pneumatic conveying system. Disperse, half-ring and ring flow patterns corresponding to different electrostatic effects through the horizontal and vertical conveying systems were observed. Three similar flow patterns were also studied in a 45A? inclined pneumatic conveying pipe. Analyses of forces acting on single particle showed that reverse flow and ring flow formation may be attributed to electrostatics. Among many factors affecting electrostatic characteristics, attrition effect was highlighted in this research work. Experiments were conducted in a rotary valve and pneumatic conveying system separately. The influence of particle attrition on electrostatic characteristics was examined. Finally, the study of hazard of electrostatic generation in pneumatic conveying systems was attempted by analyzing the sensitivity of ECT and the phenomena of spark generation due to the strong electrostatics.