(508a) Bubble Dynamics Study in a Slurry Bubble Column with a Four-Point Optical Probe

Bubble/slurry bubble columns are widely employed in petrochemical, chemical, and biochemical processes, and the related hydrodynamics and transfer characteristics studies are very important to these industrial applications. In this paper, bubble dynamics were investigated with four-point optical probe technique [1] in a 0.10 m diameter bubble/slurry bubble column under atmospheric pressure. The superficial gas velocity varied from 1.3cm/s to 13cm/s, and the range of solids loading was from 0.0 v. % to 25 v. %. The characteristics of bubbles moving upwards and downwards were studied at different radial positions. It was found that with the increase of superficial gas velocity, the local gas holdup, specific interfacial area, bubble chord length, bubble velocity, and bubble frequency increased in both the center and wall regions of the column, and it is also learned that with the increase of solids loading, bubble chord length increased due to the enhancement of bubble coalescence and the increase of apparent viscosity of the suspension, while bubble velocity changed slightly, and local gas holdup, specific interfacial area, and bubble frequency decreased with the increase of solids loading due to the formation of large bubbles.

[1] Junli xue, Muthanna Al-Dahhan, M.P. Dudukovic, and R.F.Mudde, Bubble dynamics measurements using four-point optical probe, The Canadian Journal of Chemical Engineering, 81, 1-7 (2003).