Cellular Convection in Desorbing Surface Tension-Lowering Solutes from Water

Abstract

The effect of cellular convection, driven by surface tension gradients, upon the gas-liquid•mass transfer rate was studied by desorbing four surface tension-lowering solutes from aqueous solution and monitoring the transfer process in each phase by the simultaneous transfer of tracer components. kL was enhanced as much as 3.6-fold by the cellular convection when the Marangoni number was increased above its critical value. kfi was unaffected by the cellular convection, in agreement with predictions based on estimation of the linear and velocity scales of the cellular convection. Critical Marangoni numbers showed the expected dependence on Hk(*/kL* and the surface tension equilibration time but were very much larger than theoretically predicted values.Cellular convection driven by surface tension gradients has for a number of years been recognized as having an

Onset of Rayleigh−Bénard−Marangoni Convection in Gas−Liquid Mass Transfer with Two-Phase Flow: Theory

“…This large surface viscosity number may explain the large discrepancy between the measured value and calculated value of the critical Marangoni number for the triethylamine desorption from water. 18,19,35 Conclusions Rayleigh and Marangoni instabilities in a solute transfer between a gas phase and a liquid phase which are in parallel, laminar, stratified flow between two horizontal plates have been investigated theoretically. The effect of nonlinear velocity profiles of fluid flows and the effect of nonlinear concentration profiles in gas-liquid mass transfer of practical importance have been taken into account in the linear analysis of the general Rayleigh-Bénard-Marangoni problem.…”

Part III. Experiments

“…Both Clark and King (1970) and Brian et al (1971) studied convective enhancement of desorption. In both cases volatile solutes were desorbed from water into nitrogen.…”

Influence of the Marangoni Effect on Mass Transfer in Inclined Falling Films

“…Brian et al. 12, 13 investigated the influence of the Marangoni effect on the liquid phase mass transfer coefficient through monitoring the simultaneous transfer of propylene. Linek et al 14–16 conducted an investigation of interfacial turbulence induced by oxygen absorption in 0.5 M sodium sulfite solution with argon as the tracer.…”

“…In the present work, the method developed by Brian et al 12 was employed to manipulate the Marangoni effect in our mass transfer experiment so that the mass transfer coefficient can be compared to that without Marangoni effect but under the same conditions of the fluid flow in the same mass transfer process. In order to mimic the mass transfer condition in a structured packed column, the experimental investigation was performed in inclined falling films with different inclination angles on a stainless‐steel plate.…”