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A study of the condensation of binary vapors of miscible liquids: Part 2: Heat transfer co‐efficients for filmwise and non‐filmwise condensation
Author(s) -
Mirkovich V. V.,
Missen R. W.
Publication year - 1963
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450410208
Subject(s) - condensation , thermodynamics , pentane , methylene , materials science , hexane , propane , heat transfer , methanol , chemistry , organic chemistry , physics
Heat transfer coefficients for total condensation at 750 mm. Hg of saturated, binary vapors have been measured for the four systems n‐pentane + n‐hexane, methanol + methylene dichloride, n‐pentane + methanol, and n‐pentane + methylene dichloride. Condensation was entirely filmwise for the first two systems, but was non‐filmwise (dropwise in the extreme) for the last two at low temperature differences for solutions dilute in n‐pentane. In the non‐filmwise cases the heat transfer coefficients are greater than expected for filmwise condensation, but the difference is not nearly as great as occurs for steam condensation. This indicates the existence of a resistance in the vapor film for mixtures, as postulated by Colburn and Drew in 1937. Dropwise condensation of vapor mixtures does not require a promoter, and indicates that interfacial tension forces may not always be neglected in considering the stability of homogeneous condensate films for mixtures.