Abstract
Mass transfer from a bubble to the surrounding liquid plays an important role in engineering processes. To improve the efficiency of the processes, a deep understanding of the mass transfer mechanism from bubbles to the surrounding liquid is essential. In our study, we consider the influences of bubble surface contamination (1-pentanol) on mass transfer through discussion of the relationship between bubble motions, bubble-induced surrounding liquid motions and mass transfer. We visualized the CO_2 dissolution process via LIF/HPTS (a fluorescent substance) method from the front view (zigzag plane) and side view. Moreover, we measured the surrounding liquid motions by using PIV method. According to these experimental results, horse-shoe-like vortices were observed in the bubble wake in purified water. Mass transfer was promoted by convective transportation induced by the horse-shoe-like vortices. In contrast, mass transfer in contaminated water reduced as the vortex structure changed in the bubble wake.
