Fluidization of group B particles in an acoustic field

Abstract

The behavior of group B particles (sand with mean diameter 194 μm) was studied in a sound wave vibrated fluidized bed (SVFB). The fluidized bed consists of a transparent Plexiglas tube of i.d. 54 mm and height 1 m. A loudspeaker mounted at the top of the bed was supplied by a function generator with square waves, and was used to generate the sound as the source of vibration of the fluidized bed. The effects of the power of the loudspeaker, sound frequencies, particle loading and the distance between the speaker and the bed surface on the hydrodynamic properties of the SVFB were investigated. The experimental results showed that the minimum fluidization velocity decreased with the addition of acoustic energy, and the standard deviation of pressure fluctuations became lower under the effect of sound. The sound wave also reduced the bubble rise velocity. The results were interpreted in terms of the operating parameters.