are four stages in the complete drying process:
freezing, primary drying, and secondary drying.
Applications of freeze-drying
Food industry-Freeze-drying is used to preserve food, the resulting
product being very lightweight.
Technological industry-In chemical synthesis, products are often
freeze-dried to make them more stable, or easier
to dissolve in water for subsequent use.
Document Conservation -freeze-drying can use as a recovery method of
water-damaged books and documents.
In bacteriology freeze-drying is used to conserve special strains.
Advanced ceramics processes sometimes use freeze-drying to create a
formable powder from a sprayed slurry mist
Floral preservation- Wedding bouquet preservation
Types of Freeze-dryers