Physical and transport properties governing bubble column operations

In this work, physical and transport properties governing fluid dynamics in bubble columns were studied in the heterogeneous liquid circulation regime of operation based on several published experimental data. It was confirmed that the axial dispersion phenomenon of the liquid phase could be defined by the constant Peclet number predicated on the two-phase slip velocity, which comprised the time-averaged bubbly flow velocity superimposed by the velocity of large bubbles rising in the fluid. In addition, the slip velocity of mean bubbles in the bubbly flow not only indicated a constant rising velocity of a particular liquid but also apparently reduced to that for the Higbie model with respect to the bubble diameter and its terminal rising velocity, when applied to Akita and Yoshida's dimensionless correlation for mass transfer operation (Akita and Yoshida, 1974). In the course of demonstration, it was confirmed that a semi-theoretical correlation for the gas holdup proposed by Mersmann (1978) is similar to the empirical correlation proposed by Akita and Yoshida (1973) with respect to the expression and the physical perspective.