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Heat transfer in film condensation
Author(s) -
Baer Eric,
McKelvey James M.
Publication year - 1958
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690040218
Subject(s) - condensation , thermodynamics , thermal conduction , heat transfer coefficient , heat transfer , materials science , chemistry , heat flux , thermal resistance , mechanics , physics
In this theoretical analysis of heat transfer in film condensation the total vapor‐side resistance to heat transfer is obtained by adding the resistance to conduction through the condensate film to the resistance due to the condensation process at the vapor‐liquid interface. The analysis shows that under ordinary conditions conduction in the condensate film is controlling, provided the condensation coefficient is greater than about 0.10. However, under conditions of low total pressure, low heat flux, or low condensation coefficient, the resistances of both processes must be considered. Experiments carried out on the condensation of methanol are in good agreement with the theory. Furthermore, values of the condensation coefficient for methanol are reported which show that small quantities of air will greatly reduce its magnitude. This is offered as an explantion of the commonly observed phenomenon of reduction of heat transfer rates when noncondensable gases enter a system.