Binary, Gravity-Flow Film Condensation

A predictive theory for condensation of a binary mixture on a cooled vertical plate has been formulated on the basis of the conservation laws and other fundamental physical principles. The formulation involves the analysis of the transport processes in the condensate film and in the vapor boundary layer, along with conditions of continuity, conservation, and equilibrium at the liquid-vapor interface. The analytical method is applied to the condensation of saturated binary mixtures of methanol and water vapor, and heat transfer results are obtained for a range of operating conditions. For large condensation rates, the heat transfer can be calculated by a simplified method which bypasses the detailed analysis of the vapor boundary layer.