Abstract
Mass transfer from a bubble to the surrounding liquid plays an important role in industrial applications. In our study, we discuss the relationship between the mass transfer, the bubble motion and bubble-induced surrounding liquid motion, on the basis of precise visualization. Moreover, we consider influences of the bubble-surface contamination on the above motion. In our experiments, we used purified water and 500ppm 1-pentanol solution. The dissolution process of CO_2 was visualized via LIF/HPTS (a fluorescent substance) method from front view and side view of the bubble. From these experimental results, clear horse-shoe-like vortices were observed from the bubble rear both in the first inversion section and the second inversion section in purified water. The horse-shoe-like vortices promoted the mass transfer. In contrast, the surfactant induced the vortex structure change in contaminated water. It caused the mass transfer reduction.
