Temperature Distribution during Non-Convective Air-Drying of Tape-Cast Films

摘要

Models are presented that describe the temperature distribution during non-convective air-drying of tape-cast films, where a constant-rate period is followed by a single falling-rate period. The models are extended to materials with first and second falling-rate periods following the constant-rate period at low heating intensity. During the constant-rate period, the temperature at the drying surface is steady at the wet-bulb temperature, while the temperature within the material decreases with time. It is assumed for materials with a single falling-rate period that, the temperature at the drying surface rises to the ambient value at the end of the constant-rate period. For materials with first and second falling-rate periods, the surface temperature rises above the wet-bulb temperature during the first falling-rate period, and approaches the ambient temperature during the second falling-rate period. The temperature distribution in the material during the first falling-rate period depends upon the heating intensity, and the temperature gradient increases as the heating intensity increases with lower temperature further from the drying surface. During the single falling-rate and second falling-rate periods, the temperature within the body increases with time until the temperature everywhere in the body approaches the ambient temperature at the end of drying.