A FINITE VOLUME ANALYSIS OF VACUUM FREEZE DRYING PROCESSES OF SKIM MILK SOLUTION IN TRAYS AND VIALS

A numerical code that can predict vacuum freeze drying processes in trays and vials was developed using a finite volume method to discretize the governing partial differential equations. Along with the finite volume method, a moving grid system was adopted to handle irregular and continuously changing physical domains encountered during the primary drying stage. To show the validity of the present calculation scheme, freeze drying in a tray was simulated and the results were compared with available experimental data. After successful validation, freeze drying processes in vials with different operation policies were simulated to show the capability of the present calculation tool in handling multi-dimensional freeze drying problems.