The Effect of Fine Particles Added Into Water on the Motion of Bubbles Rising Helically

LDV, PIV and some methods using ultrasonic sound have been often employed to measure multiphase flows. Fine particles are usually added into flows as tracer or scattering particles. The effect of particles added in on the flow characteristics is, however, not examined in detail. Because multiphase flows, especially gas-liquid systems, have gas-liquid interfaces, where impurities are known to aggregate, fine particles may aggregate in gas-liquid interfaces, and may affect the flow situation. Therefore, we measured the movement of helically rising bubbles to investigate the effect of fine particles mixed into the liquid phase. Polyethylene particles of 160μm and 10.6μm medium diameters are used. The reductions of helical sizes and rising and moving velocities are recognized by adding particles. The effect of particle size is also discussed.