Review of Electrostatic Sensor Applications

Abstract

Electrostatic sensors have a simple but robust structure, which can detect the electric charge from moving charged particles. Measurement of the dry particle mass flow rate, velocity, and concentration in a conveyor are the main areas of sensor application. This paper considers the measurement methods and techniques that utilize electrostatic sensors for instrumentation. The most significant applications of the sensor are reviewed and a newly developed technique in particle sizing using the spatial filtering method is explained. The results of the study re-emphasize the flexibility, reliability and cost-effective features of the electrostatic sensor for industrial applications.

An Integrated Instrumentation System for Velocity, Concentration and Mass Flow Rate Measurement of Solid Particles Based on Electrostatic and Capacitance Sensors

“…Pneumatically conveyed solid particles are charged due to friction and collisions between the particles and the pipe wall, which is one of the inherent characteristics of gas-solid flows. Based on particle charging, various electrostatic sensors have been developed for particle flow parameter measurement [ 9 , 10 , 11 , 12 , 13 , 15 , 16 , 17 ], especially for the particle velocity measurement when combined with a cross-correlation signal processing algorithm. Two identical electrostatic sensors are essential for the cross-correlation velocity measurement and are usually arranged on the pipe with a certain axial spacing ( L ).…”

“…A variety of advanced measurement techniques have been investigated and developed for the flow measurement of pneumatically conveyed solid particles based on different sensing principles [ 1 ], such as optical [ 2 , 3 ], digital imaging [ 4 , 5 ], acoustic [ 6 , 7 ], radiometric [ 8 ] and electric methods [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. Among them, optical, digital imaging and acoustic techniques are capable of dilute phase particle flow measurement.…”

“…Electrostatic and capacitance sensors also can be combined with process tomography, i.e. , electrostatic tomography (EST) and electrical capacitance tomography (ECT), to realize particle flow parameters measurement and “flow visualization” [ 9 , 20 , 21 ].…”