The electrostatics of a single-particle transported in a bifurcated pipe

Electrostatics generation due to particle-wall contact is popularly found in gas-solid systems. The working mechanism is unclear due to the complexity of particle behavior in turbulent pipe flows . This work aims to investigate the working mechanism of electrostatics generated by a single particle in a bifurcated pipe, which includes three parts: a straight part ( a) , a bifurcation part ( b) and another straight part ( c) after the bifurcation. The electrostatics was measured by an induced method together with particle trajectories taken by a high-speed camera. The statistics of particle trajectories indicate that particle-wall collision and particle rolling play the main role in determining the electrostatics generation while they vary much in each part. In part a of the bifurcated pipe, particle rolling distance dominates the electrostatics generation, longer rolling distance and higher electrostatics. In part b of the bifurcated pipe, electrostatics charge generated is dominated by particle-wall collisions rather than particle rolling, which is independent of particle material and particle size. For the whole bifurcated pipe, the electrostatics generation is determined by part c . For all particles tested in this paper, the lowest level of electrostatics generation is at part a , while the highest level is at part c (excluding 5 mm glass bead at part b ). The electrostatics generated by glass beads is higher than that by PP particles, and that by spherical PP is higher than that by elliptical PP particle. • Particle transport in a bifurcated pipe with electrostatic generation is studied. • Particle-wall collision and particle rolling determine the electrostatics generation. • Particle electrostatics generated is most from part c in the bifurcated pipe. • The lowest electrostatics generation is at part a , while the highest one is at part c.