Vibrated bed contact electrification and charge dissipation

Abstract

Some characteristics of contact electrification and charge dissipation in a vibrated bed have been studied. The experimental variables of interest were the bulk particle resistivity, the amplitude of vibration and the system electrode geometry. Theoretical models have been proposed relating the measured variables of conduction current, and induced potential in the base plate, to the charging and dissipation processes. Air breakdown has been found to limit insulating particle charge levels, following a linear increase in bed charge with time after vibration. This behaviour has been predicted theoretically. The functional dependence of the induced potential and the conduction current on the vibrational amplitude predicted theoretically for conducting particles, is in agreement with observation. Charge production and dissipation in the vibrated bed simulate the electrification characteristics of many practical bulk particle handling situations. This allows conclusions of general relevance to be deduced from the present study.