Ignition tests with discharges from bulked polymeric granules in silos (cone discharges)

Abstract

Based on earlier experiments on the occurrence of cone discharges during the filling of silos with polymeric granules further tests to investigate influencing parameters and the ignition potential have been performed. The results clearly demonstrate that cone discharges may occur from both, positively and negatively charged product, may go along the surface of the settled product or through the heap of bulked product and may occur when filling silos directly or via cyclones followed by a rotary valve. The energy of cone discharges increases with increasing silo diameter. By using a special procedure to “divert” cone discharges to a spark gap many different flammable gases and combustible powders could be ignited.