Ultrasound-assisted detachment behavior of glass beads and fragments from a fixed bubble

Abstract

Glass beads and fragments were selected as different shape materials to investigate bubble-particle detachment behavior under ultrasound-assisted detachment tests. The oscillation of the unloaded bubble was also observed. The results showed that the changing trend of projected area of a fixed unloaded bubble under ultrasound-assisted detachment test looked like a harmonic wave. The oscillation frequency of bubble was determined by the ultrasonic frequency while the oscillation amplitude of bubble increased with the increase of ultrasonic amplitude. The particles were pre-attached to the bubble surface forming a loaded bubble. The detachment behavior of particles from the bubble was evaluated using the changes of bubble-particle angle (BPA). When the initial BPA was nearly the same, the irregular glass fragments had lager final BPAs than that of glass beads under the same ultrasonic amplitude. The detachment of glass fragments from the fixed bubble needed larger ultrasonic amplitude than that of glass beads.