Effects of Contact Potential Difference and Particle Disperser on Tribo-Electrification during Solid–Air Two-Phase Flow

Abstract

This paper reviews the tribo-electrification of particles in solid-air two-phase turbulent flow with a particle feeder, an ejector, a stainless-steel branch pipe and a stainless-steel straight pipe. An unexpected charge transfer occurred between the ejector and the branch pipe, which could not be explained solely by the contact potential difference. In the ejector, an electrical current in air might be produced by the self discharge of particles with an excess charge between a nickel diffuser in the ejector and a stainless steel nozzle or the stainless steel pipe due to a reversal in the contact potential difference between particles and the stainless steel. When dual coaxial glass pipes were used as a particle disperser, the specific charge of the Polymethylmethacrylate particles became more positive along the particle flow direction due to the contact potential difference between a material of the particle and the stainless steel.