New Spiral-type Tribocharger for Granular Plastics Mixtures with Application to Electrostatic Separation

Electrostatic separation processes are emerging as the solution of choice for recycling waste from end-of-life equipment in various industries. The separation of the different constituents of such plastic mixtures is the key to successful recycling. The main objective of this work is the development of a new spiral-type tribo-charging device with an application in the field of electrostatic separation. The spiral charger offers a very high charging rate compared to other triboelectric systems. It favors collisions of the particles with the inner wall, which is very efficient to separate a mixture of ternary particles. We studied tribocharging characteristics of several types of medium-sized (2-5 mm) granular plastics. The study is conducted with samples of various e insulating materials, for several values of air velocity, pipe length and particle mass in the turbocharging device. The spiral charger was associated with a belt-type electrostatic separator to process a granular insulating mixture, consisting of three types of plastic products Polyvinyl Chloride (PVC), Polypropylene (PP) and Polystyrene (PS). The good separation obtained for this ternary mixture shows the efficiency of the new tribocharger.