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Isothermal absorption of components from dilute gaseous mixtures by falling film of liquids in irrigated plane-parallel channels for co-current laminar flows of liquid and gas were modeled taking into account the processes occurring at the gas entrance. A solution was obtained in the form of analytical expression and reduced to the solution of particular limited problems for the cases when the resistance is concentrated within the gas or the liquid. For visual representation of fluxes the plane of hydrodynamic parameters was suggested. The calculations can be carried out inside of a limited area of the plane. Outside of the area, some simplifications can be adopted: (a) mass transfer resistance is concentrated in a gas or in a liquid and (b) the concentration changes in transversal directions can be neglected or there is a boundary diffusion layer in the gas or the liquid. It was shown that in calculating of the process of gas cooling by the transversal temperature gradients in the liquid can be neglected. The restrictions on temperature difference at the entrance were found, according to them the corresponding thermophysical coefficients can be assumed to be constants and the heat exchange can be calculated using the relationships derived for isothermal absorption. The method can be applied to a wide class of problems which can be reduced to solving of convection diffusion equations with more difficult interphase boundary conditions. Compared to existing numerical and analytical methods, our approach advantage is in its simplicity, visual representation, and shorter computation time. [ABSTRACT FROM AUTHOR]

Mass transfer with solvent evaporation in the vapor-liquid two-phase film evaporators used for the removal of undesirable impurities from liquid solutions at low pressure is studied. The average concentrations of solution components in the falling liquid film are determined. The most efficient operating conditions for impurity removal, in which the resistance to mass transfer is concentrated in the liquid phase, are found. [ABSTRACT FROM AUTHOR]

Unsteady-state absorption of inorganic gases by aqueous solutions of acids and alkalis is considered using the example of two stagnant media (a liquid and a gas). It is shown that, in the general case, only two absorption modes are possible. In one of the modes, the resistance to mass transfer is concentrated in the gas phase, and, in the other, there is an instantaneous chemical reaction, in which the acceleration of two-phase physical absorption is constant. Conditions for each of these modes are found. [ABSTRACT FROM AUTHOR]

It is shown that many gases interact with water by reactions similar to that characteristic of sulfur dioxide. The unsteady-state transfer of such gases from one quiescent phase into another is studied in the cases where these gases are absorbed by a liquid or released from a liquid solution. [ABSTRACT FROM AUTHOR]