Two-phase flow in vertical tubes

Abstract

A column apparatus was designed and constructed to enable that the cocurrent two-phase flow be studied in a 0.019 m x 3.0 m (inside diameter x height) vertical tube with air and water as gas and liquid phases, respectively. In this study, bubble and slug flow patterns were produced by varying the inlet air and water flow rates. The superficial gas velocities studied were in the range of 0.0029 to 0.7042 m/s, while the superficial liquid velocity was varied from 0 to 0.1470 m/s. The resulting flow types were observed and filmed with a camcorder. Once a sufficient range of inlet conditions has been observed, flow pattern maps can be created for the vertical tube systems. More importantly, this thesis also investigated relation between rise velocity of single slug and the slug length, void fraction measured by quick closing valve technique at different air and water flow rate, rise velocity of continuously generated slugs, and air-lift pump operation within slug flow. All the results agreed well with values predicted by Nicklin’s models for slug flow except air-lift pump operation within slug flow where some discrepancies were observed.