DNS Global Foods sells Freeze dryers for food, ready meals and nutritional products at economical price. We sell small freeze dryer with 10kg 20kg capacity and medium freeze dryer with 50 Kg,100 Kg capacity and large commercial Industrial freeze dryer with 200Kg, 300 Kg and 400 Kg capacity. These freeze dryers can be used for producing freeze dried instant meals, Freeze dried fruits like Freeze Dried mango, freeze dried strawberry, freeze dried apple, freeze dried blueberries, freeze dried camel milk powder, freeze dried meals, freeze dried mushrooms, freeze dried yogurt, freeze dried pineapple, freeze dried fruits, freeze dried vegetables like freeze dried peas, freeze dried sweetcorn etc.
What is Freeze Drying ? What does Freeze Dryer do?
Freeze drying machine or Freeze Dryer removes water from a perishable material in order to preserve it, extending its shelf life and/or making it more convenient for transport. Freeze drying machines work by freezing the material, then reducing the pressure and adding heat to allow the frozen water in the material to change directly to a vapor (sublimate).
Phase 1: Freezing
The first phase involves freezing the product at less than -20 to -30oC.
Phase 2: Primary Drying (Sublimation)
The second phase is primary drying (sublimation), in which the pressure is lowered and heat is added to the material in order for the water to sublimate.
The freeze dryer’s vacuum speeds sublimation. The freeze dryer’s cold condenser provides a surface for the water vapor to adhere and solidify. The condenser also protects the vacuum pump from the water vapor.
About 95% of the water in the material is removed in this phase.
Primary drying can be a slow process. Too much heat can alter the structure of the material.
Phase 3: Secondary Drying (Adsorption)
This final phase is secondary drying (adsorption), during which the ionically-bound water molecules are removed.
By raising the temperature higher than in the primary drying phase, the bonds are broken between the material and the water molecules.
Freeze dried materials retain a porous structure.
After the freeze dryer completes its process, the vacuum can be broken by allowing air inside the chamber.
Most materials can be dried to 1-5% residual moisture.
