Brief description of freeze dryer

The basic principle of freeze-drying is based on the three-state change of water. Water has solid, liquid and gaseous states, and the three states can be transformed into each other and coexist. When water is at the triple point (temperature is 0.01°C, water vapor pressure is 610.5Pa), water, ice, and water vapor can coexist and balance each other. Under the high vacuum state, using the principle of sublimation, the moisture in the pre-frozen material can be directly sublimated into water vapor in the ice state without melting the ice, so as to achieve the purpose of freeze drying. Freeze-dried products are sponge-like, have no shrinkage, have excellent rehydration, and have very little water content. After corresponding packaging, they can be stored and transported at room temperature for a long time. Because vacuum freeze-drying has the incomparable advantages of other drying methods, the technology has been more and more popular since its inception, and has been widely used in medicine, biological products and food. Serum, strains, Chinese and Western medicine and other biological products are mostly biologically active substances, and vacuum freeze-drying technology also provides a good solution for preserving biological activity.