Diagnosis of bubble distribution and mass transfer in bubble columns with viscous liquid medium

Bubble distribution and its effects on the gas-liquid mass transfer have be en investigated in a pressurized bubble column whose diameter and height ar e 0.152 and 2.0 m, respectively. Effects of gas velocity (0.02-0.20 m/s), p ressure (0.1-0.6 MPa), liquid viscosity (1.0-38.0 MPa s) and bubble distrib ution mode (even, wall-side, central and asymmetric distribution) on the vo lumetric gas-liquid mass transfer coefficient and bubble flow behavior have been examined. Pressure fluctuations have been measured and analyzed by ad opting the deterministic chaos theory as well as spectral analysis. It has been found that the even distribution of bubbles is the best mode for mass transfer. The volumetric gas-liquid mass transfer coefficients when the bub bles are distributed in a mode of wall-side distribution have been relative ly higher than those when the bubble distribution mode has been central or asymmetric. The bubble flow regime and its transition have been detected by analyzing the pressure fluctuations in the column. The gas holdup and volu metric gas-liquid mass transfer coefficients have been well correlated with the correlation dimension of pressure fluctuations elucidating the bubble distribution in the pressurized bubble columns. (C) 1999 Elsevier Science L td. All rights reserved.