Acoustic Emission Detection of Particle Movement in a Cross-Flow Moving Bed

A passive acoustic emission (AE) technique has been applied to monitor and characterize particle movement in a cross-flow moving bed. Experimental results show that AE signals are very sensitive to particles' movement. By using spectrum analysis, both the relationship between particle discharging rate and the average signal energy and the relationship between particle moving velocity and frequency shift of the characteristic peak of acoustic signals have been found to be linear. Therefore, two correlations have been proposed to characterize the particle discharging rate and the particle moving velocity. The correlations have been validated using experimental data. The AE signal analysis was further used to detect the two adverse particle movement status: cavity and pinning. Convenient and accurate detection of particle movement is of important significance in the improvement of heat and mass transfer efficiency of the bed, thereby providing guidelines in the design of the radial flow moving bed reactor.