Experimental Modeling and Optimization of a Free-Fall Electrostatic Separator Equipped With Four Rotating-Cylinder Electrodes

Abstract

The four-cylinder electrostatic separator is a recent improvement of the “standard” free-fall equipment. The new design, which drastically reduces the inconveniences related to the impacts that might occur between the particles and the electrodes, has been adapted for applications involving the processing of micronized particles. Such applications require the use of a specific rotating-blade-type tribocharging device and an appropriate electrode cleaning system. The aim of the present work is to evaluate the effects of several factors that influence the performances of the new triboelectrostatic separator. The experiments were made on a binary mixture of polyvinyl chloride (PVC) and unplasticized PVC. The control variables considered in this study were the rotating speed of the central cylinder of the tribocharging device, the voltage applied to the electrodes of the separator, and the distance between them. The results obtained were excellent: The recovery rates and the purities of the separated products exceeded 95% for the optimum values of the control variables.