MASS-TRANSFER IN BUBBLE-COLUMNS - A COMPARISON OF CORRELATIONS

Several correlations were evaluated for predicting the gas hold-up and oxygen mass transfer coefficient in bubble columns. A recent hold-up correlation was greatly superior to the others used in this study. Onl y one of the mass transfer coefficient correlations included the effec t of the sparger area in relationship to the total surface area, yet i t was found that this relationship did have a significant effect on th e measured mass transfer coefficients. Most of the mass-transfer corre lations therefore required a correction factor. As with gas hold-up it was a recent correlation, based in part on theoretical principles, th at gave the best results. This study also developed a new correlation for the depression to be expected from detergents on the mass transfer coefficient.