Neutralisation of electrically-charged insulating granular materials

During certain electrostatic process, diverse insulating granular materials acquire large amounts of charge, and retain it longer than necessary. The aim of this work was to model and optimize the elimination of the residual static charge of such materials. The triboelectric charging was assured by a propeller-type device. The neutralisation was carried out using a commercial-type air-assisted ionizer, located at various distances above a conveyor belt that transported the charged particles. The charge of the particles was measured before and after neutralisation using a Faraday cage. Neutralisation rates close to 100% could be achieved under optimal conditions.