An Experimental study of the bubble rise velocity and trejectory in water under pressure and vacuum

Bubble rise through a liquid is an important phenomenon in the engineering practice. Bubbles are used in polymer, metallurgy, biotechnology and especially in process industries for improving the heat and mass transfer. An experimental investigation on the bubble rise velocity and trajectory in a stagnant water column under different pressure and vacuum is presented in this study. The experiments were conducted at water heights of 1 m, 1.2 m, 1.4 m and 1.6 m by introducing different bubble volumes (0.1 mL – 15.0 mL) corresponding to each height. The bubble rise velocity and trajectory were measured using a combination of non-intrusive (high speed photographic) method and digital image processing. The parameters that significantly affect the rise of air bubble are identified. The effect of different water heights and bubble volumes on the bubble rise velocity and trajectory is analysed and the influence of two different sizes of tubes on the bubble velocity for various bubble volume is discussed.