Hydrodynamic behaviors of air-water two-phase flow during the water lifting in a bubble generator type of airlift pump system

The effects of submergence ratio and gas flow rate on the performance and hydrodynamic behavior of air-liquid two-phase flow have been investigated during liquid lifting in the developed bubble-generator-type airlift pump system. Here, a mechanistic model was also developed to predict the performance of the bubble-generator-type airlift pump system on the basis of pressure balance with considering the intake angle of the injector, and the suction pipe length. A developed image processing technique was implemented to determine the hydrodynamic behaviors including gas slug velocity, water slug velocity, slug length, and gas hold up under the various submergence ratio and gas flow rate. The submergence ratio is the ratio between the static lift and the sum of static lift and static head. The experimental result was found that the minimum air flow rate for removing water is reduced by 19.17% when the airlift pump is combined with an orifice-type bubble generator. The decrease in submergence ratio causes the lower the efficiency at the critical point of airlift pump-bubble generator. Under the same submergence ratio, an increase in the supplied air superficial velocity increased the hydrodynamic parameter. A mechanistic model from pressure balance and dimensional analysis have a maximum error of 11.97% and 3.33%, respectively.