Velocity measurement of pneumatically conveyed particles using intrusive electrostatic sensors

This paper reports recent developments of electrostatic sensors for the continuous velocity measurement of particles in pneumatic conveying pipelines. The optimization of intrusive electrostatic sensors is investigated through finite-element modeling and experimental evaluation. The effects of electrode dimensions and intrusion depth on sensor signals and correlation-based velocity measurement are addressed. The modeling results were validated for a range of velocity profiles using a dedicated belt rig, which produces idealized particle flow. A series of online experimental tests using circular and rod electrodes was conducted on an industrial-scale pneumatic conveyor injecting pulverized coal and biomass particles. The results demonstrate that electrostatic sensors are capable of providing reliable velocity measurement of pneumatically conveyed particles with excellent repeatability and fast dynamic response in an industrial environment.