Levitation of air bubbles in liquid under low frequency vibration excitement

Abstract

This experimental study reports the influence of low frequency vibrations, in the range of 50-250 Hz, on the rise of single gas bubbles injected into a column of liquid. Water and a high-viscosity hydrocarbon-oil were used as the liquid phase. For a specified set of operating conditions the bubble can be made to levitate, i.e. held stationary in the column. The bubbles employed had volumes that varied from 0.01 to 0.6 mL. The height of the liquid, h, above the position at which the bubble is levitated was determined for a wide range of operating conditions (bubble volume V_b, vibration frequency, f, pressure above the liquid surface, P, and the vibration amplitude, λ ). The experimental values of h are in good agreement with the theoretical model of Baird (1963. Resonant bubbles in a vertically vibrating column. Canadian Journal of Chemical Engineering 41, 52-55).