Hydrodynamics and mass transfer in non‐Newtonian solutions in a bubble column

Abstract

AbstractUntil now the oxygen transfer in viscous non‐Newtonian solutions has been studied only in bubble columns of about 0.14‐m diameter. Recently Godbole et al. (1982) reported much smaller gas holdups in Carboxy Methyl Cellulose solutions (CMC) for a large‐diameter column. Therefore, the gas holdups, volumetric mass transfer coefficients, and specific gas‐liquid interfacial areas are measured in CMC solutions using a bubble column of diameter 0.305 m and height 3.4 m. The transition from churn‐turbulent to slug flow regime occured at higher viscosities and the gas holdups and volumetric mass transfer coefficients were lower in both flow regimes than reported for smaller column diameters. Empirical correlations are presented for the gas holdup, volumetric mass transfer coefficient, and specific gas‐liquid interfacial area which would be suitable for the design of fermentors.