Endurance and Heat-Transfer Performance of Polymer Coatings for the Promotion of Dropwise Condensation of Steam.
Abstract
Ten polymer coatings were evaluated for the long term promotion of dropwise condensation of steam. Four of the coatings were experimental coatings developed by the Naval Research Laboratory and six were commercial coatings. Continuous dropwise condensation in excess of 10,000 hours was obtained for several of the coatings that were applied to rough surfaces. Three commercial coatings, in addition to an NRL fluoroacrylic coating, were evaluated for heat-transfer performance. The effects of roughness, substrate thermal conductivity, coating thickness, and vapor velocity on the heat-transfer coefficient were studied for dropwise condensation of steam on a horizontal tube. Dropwise heat-transfer coefficients were also determined for steam condensing on silver-electro-plated tubes, in order to compare the results with those from the polymer-coated tubes. Heat-transfer coefficient enhancement factors of as much as 10-12 were obtained for dropwise condensation when compared to filmwise results. Originator supplied keywords include: Dropwise Condensation, Polymer Coatings, Heat-transfer Enhancement, Fluoroepoxy, Fluoroacrylic, Parylene.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1984
- Accession Number
- ADA154743
Entities
People
- D. J. Looney
Organizations
- Naval Postgraduate School