Study on Dropwise Condensation Curves : Measurement of Propylene Glycol Vapor on PTFE Coated Surface

Abstract

By realizing dropwise condensation of propylene glycol vapor on PTFE coated surface, dropwise condensation curves were measured over a wide range of surface subcooling and the modes of condensate were observed using video recording and photography simultaneously. The parametric trends were presented by the experiments conducted for the four cases i.e., two values each for departing drop diameters and vapor pressures. Although the curve shapes of propylene glycol vapor were similar to those of steam on oleic acid promoted copper surface, the values of heat transfer coefficient and heat flux were much smaller and the transition mode from drop type to film type was quite different. Further, the effect of non-condesable gas on heat transfer was demonstrated to be negligible in the measurement.