Premises of using triboelectric charge for identification of the granular product flowing in a pneumatic transport system

Abstract

The triboelectric phenomena resulting from impacts between the particles and the wall are known to affect the efficiency of suction-type dilute-phase transport systems. However this triboelectric charge could be used as an “image” of the granular product passing through the pipe. The aim of this paper is to investigate the feasibility of measuring the triboelectric charge acquired for using as an electrostatic detection sensor for the identification of the product passing through the pipeline. Useful information about the product could be deduced such as the nature (plastic or metal), the composition (simple or binary sample), granulometric size. The study was conducted with mm-size and micronized plastic particles. A Faraday cage sensor connected to an electrometer has been employed for the measurement of the charge, which is equal to the charge transferred to the particles passing through it. The measured data were processed by a virtual instrument developed in Labview. Under the specific conditions of the experiments described in this paper, the charge of the processed particles was found to give useful information about the flowing material. Obtained results have shown that the measured triboelectric charge reproduced the type of product flowing through the pipe. When passing a binary product, it becomes possible by measuring the triboelectric charge, to determine the nature of the product passing through the pipe and even to know the percentage composition of the granular mixture.