Electric charge measurement in pneumatic installations

Abstract

Measurements of a net electric charge carried by solid particles travelling along a conveying pipe in pneumatic transport installations are very important especially for monitoring the ESD dust ignition hazard associated with pneumatic transport of solids. The electrostatic, inductive, non-contact method permits rapid and continuous measurements of the net charge of particles flowing in pipes of a special pneumatic transport installation in a quasi-real-time mode. Some preliminary tests were carried out using granulated polypropylene for different mean solids mass flow rates, and their results show certain relationships between the measuring ring probe voltage and the net particle charge, and are presented in this paper. The specific charge was also determined for the known values of the mass flow rate of particles.