GAS HOLD-UP AND VOLUMETRIC MASS-TRANSFER COEFFICIENT IN BUBBLE-COLUMNS UNDER FOAM CONTROL

Experimental measurements of the gas hold-up and volumetric mass trans fer coefficient have been made for bubble columns (BCs) treating vario us foaming liquids under mechanical and chemical foam control. The gas hold-up and the volumetric mass transfer coefficient in a mechanical foam-control system (BCs with rotating-disk mechanical foam-breakers) were larger than those in a chemical foam-control system (BCs with an antifoam agent added). Correlations for the gas hold-up and the volume tric mass transfer coefficient in BCs under foam control are presented . Comparison of the volumetric mass transfer coefficient between the m echanical foam-control system and the chemical foam-control system in terms of the specific power input also demonstrated higher mass transf er performance and saving power requirements for the mechanical foam-c ontrol system.