Publication:
An evaluation of polymer coatings for the promotion of dropwise condensation of steam

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Authors
Holden, Kenneth M., II
Subjects
dropwise condensation
heat-transfer enhancement
ultra-thin polymer coatings
hydrophobic
fluoroepoxy
fluoroacrylic
Advisors
Marto, P.J.
Date of Issue
1984-03
Date
March 1984
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
Fifteen polymer coatings were evaluated for their ability to promote and sustain dropwise condensation of steam to enhance the heat transfer capability of steam condensers. Of the fifteen coatings, nine employed a fluorcpolymer as a major constituent. Of the other six, four were hydrocarbons, one a chlorocarbon and one a silicone. Each coating was applied to four different metal substrates: brass, copper, naval brass, and titanium. while exposed to steam at atmospheric pressure, each coating was visually evaluated for its ability to promote dropwise condensation. Observations were conducted over a period of 4000 hours. Hardness and adhesion tests were performed on selected specimens both before and after exposure. On the basis of sustained performance, six coatings were selected for heat transfer performance evaluation. A separate apparatus was used in which coated copper tubes were mounted horizontally in a test section through which steam flowed vertically downward. Vapor-side heat-transfer coefficients were inferred from overall measurements. Test results indicate that the outside condensing coefficient can be increased by a factor of five to eight through the use of polymer coatings to promote dropwise condensation.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
NPS-69-84-003
Sponsors
National Science Foundation, Division of Engineering, Washington, DC under MEA82-03567
Funder
National Science Foundation, Division of Engineering, Washington, DC under MEA82-03567
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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