The flow pattern and oxygen transfer characteristics were studied for laboratory concentric tube air-lift reactor with air-water system.
The mixing time, circulation time, gas holdup, and overall mass transfer coefficient were measured according to change of dispersion type, riser-to-downcomer cross sectional area ratios, and air flow rate. Some correlations were obtained to express the effects of variables on gas holdup and mass transfer coefficient. Overall gas holdup and mass transfer coefficient in the type of gas dispersion into annulus were found to be larger than those in case of the type of gas dispersion into draft tube.