Experimental observation of charged particles trajectories in roll-type electrostatic separators

Accurate prediction of the effects of the various factors that might influence the outcome of novel electrostatic separation process requires reliable physical and mathematical models for the numerical simulation of particle trajectories. The major objective of this paper was to demonstrate that the use of a high-speed camera for recording particle trajectories could be instrumental in refining the understanding of the complex physical phenomena that occur in these electrostatic devices and in improving their operating conditions, based on valid numerical simulation results. The experiments were carried out with spherical conductive particles, using a roll-type corona-electrostatic separator. The particles trajectories were recorded using a high speed-camera at acquisition frame rate of 200 fps. The electrical field computation and the resolution of the differential equation of motion of the particles under the action of electrical and mechanical forces exerted on them enabled the prediction of the outcome of the separation process. The study was carried out for particles of different sizes, for different voltages and for different electrode positions. The simulation results were in good agreement with the experimental data.