GAS HOLD-UP AND LIQUID-MIXING AT LOW AND INTERMEDIATE GAS VELOCITIES .1. AIR-WATER SYSTEM

Gas hold-up and liquid phase dispersion experiments have been carried out in a 0.06 m bubble column at varying liquid and gas velocities. Th e results obtained show that the coefficient of liquid mixing varies w ith the flow regime. The isotropic turbulence theory of Baird and Rice (Chem. Eng. J, 9 (1975) 171) was used to provide dimensionally consis tent correlations for the chain bubbling, bubbly and churn turbulent f low regimes. The gas hold-up was determined to increase with gas veloc ity in the chain bubbling and bubbly flow regimes. The results obtaine d from this study also show that the Froude number represents a useful criterion for mapping flow regimes in vertical bubble columns.