Experimental and numerical evaluation of two electrode systems for plate-type electrostatic separators

Plate-type electrostatic separators are commonly employed for the selective sorting of conductive and non-conductive granular materials. The separation generally takes place in the electric field generated between an elliptical electrode, which is connected to a high voltage supply, and a grounded S-shaped electrode. The aim of the present work is to evaluate the separation performances attainable with another electrode system, consisting of two metallic plates, a short one that is connected to the high-voltage and a long one that is grounded. The experiments are carried out with a mixture of mm-size granules of copper and PVC, originating from mechanically processed electric wire wastes. The results of the composite factorial experimental designs performed for each of the two electrode systems are quite similar. The numerical modelling and simulation of the electric field and of particle trajectories explain the experimental findings and support the practical recommendations regarding the industrial application of the two electrode systems.