The basic principle of freeze dryer is based on the change of the three states of water. Water has three states of solid, liquid and gas, which can be transformed and coexisted. When water is at the triple point (temperature is 0.01°C, vapor pressure is 610.5pa), water, ice and steam can coexist and balance each other. Under high vacuum conditions, using the principle of sublimation, the moisture in the pre-frozen material is directly sublimated to water vapor without melting ice, so as to achieve the purpose of freeze-drying.
In-situ loyphilizer has the advantages of flexible structure, excellent performance, energy saving and environmental protection, and can meet the requirements of most experiments and pilot production.
Since the material is frozen and the temperature is very low, the temperature of the heat source is not high, and the use of normal temperature or low temperature heaters can meet the requirements. If the freezing chamber and the drying chamber are separated, the drying chamber does not need to be insulated, and there will be no large heat loss, so the utilization of thermal energy is very economical.
Advantages of in-situ freeze dryers:
1. Because it is dried in a frozen state, the volume is almost unchanged, the original structure is maintained, and no concentration phenomenon occurs.
2. The material dried by the in-situ freeze dryer is loose and porous, and it is sponge-like. After adding water, it dissolves rapidly and completely, and it restores its original properties almost immediately.
3. Many heat-sensitive substances will not be denatured or inactivated. When drying at low temperature, some volatile components in the material are lost very little.
4. Since the drying is carried out under vacuum, there is very little oxygen, so some easily oxidizable substances are protected.
5. During the freeze-drying process, the growth of microorganisms and the action of enzymes cannot proceed, so the original properties can be maintained.
6. Drying can remove more than 95% to 99% of the moisture, so that the dried product can be stored for a long time without deterioration.