Measurement of Gas Holdup Profiles in A Gas Liquid Cocurrent Bubble Column Using Electrical Resistance Tomography

Abstract

Radial variation of the gas holdup and mean holdups were investigated in 0.160m i.d. bubble column using electrical resistance tomography with two axial locations (Plane 1 and Plane 2). In all the experiments tap water was liquid phase and air was gas phase. Superficial gas velocity was varied from 0.02 to 0.25 m/s, and the liquid velocity varied from 0 to 0.01 m/s. The effect of liquid velocity on the mean holdups and radial gas holdup distribution was discussed. The experimental results showed the liquid velocity influence slightly the mean holdup and radial hold‐ups distribution in the operating condition, and the liquid flow can improve the trasition gas velocity for homogeneous regime to heterogeneous regime. Meanwhile the average column gas holdups as a function of gas velocity derived from differential pressure method and electrical resistance tomography method. The agreement between results obtained by two methods is generally very good in homogeneous regime. But in transition regime and heterogeneous regime, results with ERT are slightly larger than one with the differential pressure method. According to the experimental results, a correlation for the centreline holdup is obtained.