Two-phase flow pattern transitions of short airlift pumps

The flow behaviour and flow pattern transitions of two-phase flow of short airlift pumps were investigated in a wide range of submergence ratios and air discharges. This was obtained using conductivity signals from point-conductivity probes along with visual observations. It was found that the transitions between the various flow patterns depend on the submergence ratio and that the two-phase flow structure can change characteristics along the riser tube. A flow regime map is presented which takes into account the operational parameters, namely superficial gas velocity and submergence ratio, of the airlift pump.