Gas holdups and friction factors of gas-liquid two-phase flow in an air-lift bubble column.

Abstract

Gas holdups and friction factors were measured for gas-liquid parallel two-phase flow in an air-lift bubble column. Velocities of gas and liquid, liquid viscosity, and surface tension were varied. The results were correlated with dimensionless equations. As to the gas holdups (εG), Akita-Yoshida''s equation1) for batchwise processes was modified to the following form to suit continuous parallel gas-liquid flow operation: εG(1-εG)-4=0.20(gD2ρL/γ)1/8(gD3/v2L)1/12(UGL/(gD)1/2) As to the friction factors (f), the following correlation was proposed. f=0.0468(UL/(gD)1/2)-1.1ε0.5G These equations are useful for estimations of gas holdups, distribution of gas holdup along the column height, and liquid circulation velocities between a riser and a downcomer in an air-lift bubble column.