Reverse Process of Superheated Steam Drying from Condensation to Evaporation. Simple Calculation Method of the Reverse Process by using One-Dimensional Heat Transfer Models.

Abstract

For clarification of the mechanism of heat and mass transfer in the early stages of superheated steam drying which accompanies condensation and evaporation, we had done both the experiments and the simple calculation for a semiinfinite heat transfer model. And we found the existence of "reverse point" at which neither condensation nor evaporation occurs in the early stage of superheated steam drying. In this report, in order to investigate the physical reason of the reverse point and its change according to the shapes of heat transfer model, similar analytical and experimental methods were applied for both a spherical and a large slab heat transfer models. As a result, restoration time changes in the range of 3.2∼10times the reverse time with changes of scale, heat transfer rate and initial temperature of the heat transfer models.