EFFECTIVENESS OF COMPOSITE COPPER GRAPHITE FLUORIDE PLATINGS FOR PROMOTING DROPWISE CONDENSATION OF STEAM - A PRELIMINARY-STUDY

Composite platings of copper and graphite fluoride codeposited on solid copper substrates were tested as potential promoters of dropwise condensation of steam. It was confirmed that steam condenses dropwise on the platings. Despite their exceptionally strong ''water repellency'' in an ordinary sense, however, we found no reduction, using the composite platings in place of conventional promoters, in the critical departure size of condensate drops, which disappointed us in the idea of using such platings to produce a more enhanced condensation heat transfer. A hypothetical explanation is made on the apparent inconsistency between the manner of water-to-plating contact in the air and that in a condensing steam.