A small vacuum freeze dryer is mainly used in the production of medicine and food. Preservation of organisms, drying of micro powder, etc. In medicine, it is mainly used to produce some valuable and heat-sensitive drugs, such as enzymes, vaccines, hormones, various antibiotics, etc; In terms of food processing, the main focus is on the production of fast-maturing food, long-term storage, and transportation of food, such as coffee, seafood, fruits, vegetables, condiments, etc. freeze-dried food can ensure that the color, flavor, aroma, and nutrition remain unchanged; The preservation of organisms mainly includes plasma, bacteria, arteries, bones, skin, cornea and nerve tissue. Freeze-drying technology is playing an important role in the research of anatomy, pathology, zoobotany and physiology, and chemistry. The drying of micro powder is mainly used for the drying of some ultra-fine powders such as amino acids, metal powder, and mineral powder.
After the small vacuum freeze dryer starts working, the water vapor sublimates from the frozen products to the capture surface of the condenser and recondenses into ice. In order to obtain stable sublimation and condensation, heat is supplied to the product by the plating layer and removed from the capture surface of the condenser. The capture surface of the condenser must maintain a lower temperature than the product. The heating and cooling temperature of the plating layer depends on the working cycle and process requirements. The cooling and heating of the shelf are carried out through the heat transfer of the heat transfer oil. In order to make the heat transfer oil circulate continuously in the whole system, a shielded double body pump is added in the pipeline to make the heat transfer fluid circulate forcibly.
The circulating pump is a pump body. When two motors work at ordinary times, only one motor operates. If one motor does not work normally, the other will be switched in time. The system has a good backup function and wide applicability. At the outlet of the pump, we installed a pressure gauge reflecting the outlet pressure and a pressure relay. At the same time, we added an overtemperature alarm relay on the electric heating pipe. The vacuum system consists of a freeze-drying box, condenser, vacuum valve, vacuum pump, vacuum pipeline, vacuum measurement, etc. The vacuum pump group is used to form a strong suction capacity to form a vacuum in the drying chamber and the condenser. On the one hand, it promotes the evaporation (sublimation) of water in the drying chamber under a vacuum. On the other hand, the vacuum system forms a vacuum gradient (pressure difference) between the condenser and the drying chamber. The moisture in the front box is sublimated and captured by the condenser.
The freeze-drying box of a small vacuum freeze-drying machine mainly has two shapes; Cylindrical; Rectangular box. From the stress condition of a vacuum container, of course, the spherical or cylindrical container is reasonable, but considering the effective use of space, beautiful appearance, and other factors, most freeze-drying equipment adopts the rectangular box structure with stiffeners. During design, special attention shall be paid to strength and stability calculation to prevent deformation.
