Temperature distribution in a vial during freeze-drying of skim milk

The temperature distributions in a vial during freeze-drying of a skim milk solution were experimentally determined by superposing temperature histories measured at different positions in separate experimental runs. The obtained temperature distribution clearly indicates the multi-dimensional drying characteristics of freeze-drying in a vial. Along with the experiments, a numerical analysis program based on a finite volume method with a moving grid system was developed and its validity was tested.