Velocity measurement of pneumatically conveyed particles via a simple current signal technique and the influence of electrostatic charge

Abstract

Particle velocity in pulse feeding pneumatic conveying was measured utilizing current signal analysis and video imaging. Glass beads and silica particles were conveyed in a conductive tube (ID of 4.57 × 10 −3 m) at gas velocities of 7, 15, and 30 m/s. To measure particle velocity, electrical current signal method was used with a new approach that uses raw current data and eliminates signal conditioning and cross-correlation analysis. This technique was successful and results were comparable to video imaging results. The conveyed particles' charge was measured to determine its influence on particle velocity. 30 m/s gas velocity resulted in a turbulent flow and greater charge generation causing more deviations between particle and gas velocity due to the enhancement of particles' radial motion. Finally, the comparison of results with predictions of existing models revealed that further research is necessary to better understand the effect of particles' motion and charge on their conveying velocity. Video imaging and current signal measurement techniques and the acquired electrostatic charge during pneumatic conveying. • Particle velocity in pneumatic conveying was measured based on particles charge. • A simplified technique based on electrical current signal method was proposed. • Influence of particles electrostatic charge on their velocity was investigated. • Existing models overestimated particle velocity in the presence of electrostatics. • Existing models predictions were not in agreement to the measurements at high gas velocities.