Modeling of Mass-transfer in Bubbly Flows Encompassing Different Mechanisms

Models proposed to describe the liquid side mass transfer coefficient in absorption prosesses differ widely in such basic questions as on which of the local flow variables they are based. Comparison of different alternatives with experimental data taken from the literature suggests that there are two basic mechanisms, a laminar and a turbulent one, each of which dominates under suitable conditions. A dimensionless number that allows to identify the corresponding regimes is suggested together with a preliminary model encompassing both. New experiments will be needed to come to a final conclusion.