Full Article: Freeze Drying—How It Works And Its Benefits

The purpose of freeze drying is to remove a solvent (usually water) from dissolved or dispersed solids.
The principles of freeze drying are simple.

1. Freezing: The product is frozen. This provides a necessary condition for low temperature drying.
2. Vacuum: After freezing, the product is placed under vacuum. This enables the frozen solvent in the product to vaporize without passing through the liquid phase, a process known as sublimation.
3. Heat: Heat is applied to the frozen product to accelerate sublimation.
4. Condensation: Low-temperature condenser plates remove the vaporized solvent from the vacuum chamber by converting it back to a solid. This completes the separation process.