Researches on Vacuum Freeze-Drying

抄録

The rate of sublimation dehydration by the process of Vacuum freeze-drying was investigated after our former reports on the researches of sublimation of ice. Analyses of the temperature distribution in the sublimating materials by numerical methods and of the ideal drying-characteristics were presented. In the above analysis, the rate-determining steps considered were the rate of phase change from ice to vapor, the rate of heat supply to the sublimating surface and the rate of mass transfer of vapor through porous sublimated materials by the Darcy's and the Knudsen's flow. The analitical results were compared with experiments using homogeneous beds of sands and beef in pressure range 1-10^-2 mmHg.