Condensation of Vapor from Vapor-Gas Mixture at Low Pressure

Equations of rate of condensation over a wide range of vapor concentration

Abstract

Rate of condensation of vapor from vapor-gas mixture flowing in a tube under reduced pressure was analysed numerically and measured experimentally. Under the condition of laminar flow of gas phase, two equations for the rate of condensation are proposed. One of them, to be applied when vapor concentration is high, is formulated from the result of numerical calculation performed with the aid of Baasel's simplification of the basic transport equations. For low concentration of vapor, another equation is derived by applying Hausen's equation of the average heat transfer coefficient to mass transfer. Experimental results obtained for the three systems C₂H₅OH-air, n-C3H₇OH-air and n-C₄H₉OH-air over a wide range of vapor concentration are in good agreement with these two equations.