Studies in condensation

• Main Author: Sardesai, R. G.
• Published: University of Manchester 1979
• Subjects: 536.7
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.347316

A comprehensive theoretical and experimental study is made of the following condensation processes, occurring in cocurrent downwards flow within a single vertical tube and with negligible shear effects at the vapour-liquid interface. 1. Condensation of a vapour in the presence of a non-condensable gas. 2. Condensation of binary vapours of miscible liquids. 3. Multicomponent condensation of the vapours of miscible liquids in the presence of a non-condensable gas. 4. Condensation of binary vapours of immiscible liquids where the vapours are not at eutectic conditions. 5. Condensation of vapours of immiscible liquids in the presence of a non-condensable gas. Condensation of binary vapours or vapour-gas mixtures has been widely investigated and processes I and 2 are studied in this work to test existing design methods particularly the evaluation of heat and mass transfer coefficients and the enhancement of transfer rates due to the presence of the condensate. The experimental and theoretical procedures of this work are validated to provide a firm basis for the new studies. Multicomponent condensation of the vapours of miscible liquids has been a subject of several recent studies. New data are presented and the following models of multicomponent mass transfer are compared. 1. The linearised theory of Toor (1964) 2. The matrix method of Krishna and Standart (1976) 3. Simple effective diffusivity models. Particular emphasis is given to the significance of diffusional interactions and conditions under which the simple effective diffusivity model is adequate are identified. Little work is reported in the literature on condensation of the vapours of immiscible liquids and these studies are limited to binary eutectic mixtures. In this work extensive new data are reported on condensation of non-eutectic mixtures and multicomponent mixtures containing a non-condensable gas. The data are compared with existing correlations of the heat transfer coefficients of immiscible liquid films. New methods are reported to allow design of condensers carrying immiscible liquids. where the vapour is of non eutectic composition or contains a non-condensable gas. These methods are considered in relation to the experimental data.