Axial and Radial Mixing Characteristics in Bubble Columns

Gas holdup and axial and radial dispersion coefficients of continuous liquid phase have been studied in a 10.2 cm-ID acryl column. The effects of gas flow rate (1.0-10.0cm/s) and liquid flow rate (2.0-12.0 cm/s) on the hydrodynamic characteristics of a bubble column have been determined. Gas holdup, axial and radial dispersion coefficients of liquid phase, and liquid circulation velocity in the column were increased with an increase in gas flow rate. However, increasing liquid flow rate the gas holdup was decreased and the radial dispersion coefficient of liquid phase was increased. The axial dispersion coefficient and the circulation velocity of liquid phase were little affected by the liquid flow rate. Bubble rising velocity in the column was analyzed by employing the drift flux model, and the two dispersion coefficients of liquid phase were correlated by means of isotropic turbulence model.