Sublimation behavior of annular frost layer by impinging jet flow

The present paper has dealt with a new method of defrosting by using the frost sublimation phenomenon which occurs below the triple point of water (273.16 K, 610.5 Pa). The present experimental study has focussed to examine the mass transfer of the annular frost layer developed on a cooling pipe exposed to an impinging jet flow. Morphology of the frost layer during sublimating was observed by using a CCD camera. It was understood that the mass flux of the frost layer increased with increasing the jet flow velocity and the difference of the mass concentration of water vapor between the frost surface and the inpinging jet flow. The nondimensional correlation equations of mass transfer of defrosting were derived as functions of various parameters.