Effect of liquid viscosity on liquid side mass transfer coefficient at vertical film flow on expanded metal sheets

Abstract

Experimental results are presented on the effect of liquid viscosity on absorption rate of carbon dioxide into a liquid film flowing downward the vertical surface of expanded metal sheets. On basis of these results the conclusion has been reached that the Highbie model does not enable to predict the effect of kinematic viscosity on liquid side mass transfer coefficient k1. The film-penetration model has been proposed where the existence of non-mixed region is assumed at the interface with the thickness ϑ and to it periodically incoming disturbances with the length scale of disturbance λ and characteristic Reynolds number of disturbance equal to one. On basis of experimental data were evaluated the dimensionless thicknesses of the film and penetration regions ϑ+ = 0.04 and λ+ = 10.6. A good agreement of the measured and calculated values of the mass transfer coefficient k1 were obtained for three types of expanded metal sheets of vertical pitch diagonal 10, 16 and 28 mm and nine liquids with kinematic viscosities within the range from 0.6 to 15.1 μm2s-1.