Gas hold-up and volumetric oxygen transfer coefficient in an aerated agitated vessel without baffles having forward-reverse rotating impellers |
| |
Authors: | M Yoshida A Kitamura K Yamagiwa A Ohkawa |
| |
Abstract: | Gas hold-up and volumetric oxygen transfer coefficient were studied in a gas-liquid contactor without baffles, containing multiple impellers with four delta-type blades. The blades of each adjacent impeller were offset by 45° in an alternating manner. The direction of rotation of the impellers periodically was reversed. This new type of agitated gas-liquid contactor was denoted as “AJITER”. The effects of the gas sparging rate, the forward-reverse agitation rate and the number of impellers on the gas hold-up and volumetric oxygen transfer coefficient in the AJITER when different types of gas spargers were used were evaluated experimentally for an air-water system. Empirical relationships are presented to predict the gas hold-up and volumetric oxygen transfer coefficient. The differences in performance between the AJITER and existing types of gas-liquid contactors are discussed in terms of the differences in the gas hold-up and volumetric oxygen transfer coefficient due to changes in the superficial gas velocity. |
| |
Keywords: | gas hold-up volumetric mass transfer coefficient vessel without baffles forward-reverse rotating impeller |
|