Experimental Study and CFD Simulation of Mass Transfer Characteristics of a Gas-Induced Pulsating Flow Bubble Column

Oxygen gas-liquid mass transfer coefficient was measured in a gas-induced pulsating flow bubble column. Pulsating amplitude had a great influence on kla under pulsating state of equal base flow and pulsating flow, which was enhanced up to 30 % compared with that under steady state; however, it had a negative effect on mass transfer under a fixed low base flow. It was also found that kla had a negative linear correlation with pulsating frequency. A CFD model considering bubble population balance was applied to simulate the distributions of the gas-liquid interfacial area and the liquid side mass transfer coefficient, finding that the former was in a tight relationship with gas holdup and bubble size distribution, while the latter showed little dependence on fluid flow. Dissolved oxygen (DO) concentrations in liquid phase were predicted, which demonstrated an increasing trend along with time until an almost homogeneous distribution was achieved.