社団法人日本機械学会 Acta Medica Okayama 0387-5016 66 651 2000 着霜2円管の昇華による除霜挙動 212 219 EN Hideo Inaba Akihiko Horibe Yoshiaki Kawakami The present paper has dealt with a new defrost measure by using sublimation phenomenon which occurs below the triple point of water (273.16 K, 610.5 Pa) The present experimental study has focused to examine the mass transfer of annular frost layers developed on two cooling horizonal pipes set in a vertical direction which was exposed to an impinging jet air flow. The morphology of the frost layer during sublimating was observed by using a CCD camera. The nondimensional correlation equations of mass transfer were derived as a function of various parameters. No potential conflict of interest relevant to this article was reported.