What is the working principle of the freeze dryer (freeze dryer)?

A freeze dryer (freeze dryer) is a technique for drying by the principle of sublimation. It freezes the dried material at a low temperature and then directly sublimates the frozen water molecules into water vapor under a suitable vacuum environment. The process of escaping. The product obtained by lyophilization is referred to as lyophilizate (freeze-dried) and the process is referred to as freezing (lyophilization).

The substance is always at a low temperature (freezing state) before drying, and the ice crystals are uniformly distributed in the substance, and the sublimation process does not cause concentration due to dehydration, thereby avoiding side effects such as foaming and oxidation caused by water vapor. The dry material is porous in the shape of a dry sponge, the volume is basically unchanged, and it is easily soluble in water and restored to its original state. Physical and biological denaturation of dry matter is prevented to the greatest extent.

The lyophilization machine is composed of a refrigeration system, a vacuum system, a heating system, and an electrical instrument control system. The main components of the freeze dryer are dry box, condenser, refrigeration unit, vacuum pump, heating/cooling device, etc. The lyophilizer works by freezing the dried object to below the triple point temperature, and then sublimating the solid water (ice) in the article to water vapor under vacuum conditions, removing it from the article, and drying the article. . After the material is pretreated, it is sent to the quick freezing warehouse for freezing, and then sent to the drying chamber for sublimation dehydration, and then packaged in the post-treatment workshop. The vacuum system establishes a low pressure condition for the sublimation drying chamber, the heating system provides sublimation latent heat to the material, and the refrigeration system provides the required cooling capacity to the cold trap and the drying chamber.

High-efficiency radiant heating, uniform heating of materials; high-efficiency water-trapping cold trap, and rapid defrosting; high-efficiency vacuum unit and oil-water separation; parallel-type centralized refrigeration system, multi-channel cooling on demand, stable working conditions, Conducive to energy saving; using artificial intelligence control, high control precision and easy operation.

The quality requirements for freeze-dried products are: no change in biological activity, uniform appearance, uniform shape, firm structure, fast dissolution rate, low residual moisture, high quality products, and a comprehensive theory and process for freeze-drying. Understanding. The lyophilization process includes three stages of pre-freezing, sublimation and re-freezing. Reasonable and effective shortening of the freeze-drying cycle has obvious economic value in industrial production.