BUBBLE CHORD LENGTH DISTRIBUTION IN 3-PHASE FLUIDIZED-BEDS

Abstract

Three ideal bubble chord length distributions have been derived for three different bubble shapes (spherical, ellipsoidal and spherical-cap). The measured chord length distributions in three-phase fluidized beds have been analyzed by the combined bubble length distribution model based on the ellipsoidal and spherical-cap bubble shapes. The combined bubble length distribution predicts well the measured bubble length distribution in three-phase fluidized beds. It has been found that the distribution approaches that for ellipsoidal-shaped bubbles in the bubble-disintegrating regime and that for spherical-cap-shaped bubbles in the bubble-coalescing regime and/or in the slug flow regime. The ellipsoidal-bubble fraction increases with increasing liquid velocity and particle size, but decreases with increasing gas velocity and liquid viscosity.