The vacuum dryer consists of a refrigeration system, a vacuum system, a heating system, and an electrical instrument control system. The main components are drying ovens, condensers, refrigeration units, vacuum pumps, heating/cooling devices, etc. Its working principle is to freeze the items to be dried below the triple point temperature, and then vacuum the solid water (ice) in the product to directly sublimate into water vapor, remove from the items, and make the items dry. After the material is pre-treated, it is sent to a quick-freezing chamber for freezing, then sent to a drying warehouse for sublimation and dehydration, and then packaged in a post-processing workshop. The vacuum system establishes a low pressure condition for the sublimation drying chamber, the heating system provides the sublimation latent heat to the material, and the refrigeration system provides the required coldness to the cold trap and the drying chamber.
The equipment adopts high-efficiency radiant heating, and the material is heated evenly; the high-efficiency catching cold trap is adopted, and the quick defrosting can be realized; the high-efficiency vacuum unit is adopted, and the oil-water separation can be realized; the parallel centralized refrigeration system is adopted, and the multiple-way on-demand cooling is provided, the working condition is stable , Advantageous energy-saving; artificial intelligence control, high control accuracy, easy operation. The quality requirements for freeze-dried products are: constant biological activity, uniform appearance, color, full shape, firm structure, fast dissolution rate, and low residual moisture. To obtain high-quality products, we should have a more comprehensive understanding of the theory and process of freeze-drying.
The lyophilization vacuum drying process includes three stages of pre-freezing, sublimation and re-freezing. Reasonably and effectively shortening the cycle of lyophilization has obvious economic value in industrial production. The vacuum dryer passes a thermal energy source (such as hot water, low pressure steam or heat transfer oil) in the sealed interlayer, and the heat is transferred from the inner shell to the dried material. Under the drive of power, the tank body rotates slowly, and the materials in the tank are continuously mixed to achieve the goal of enhanced drying. The material is in a vacuum state, and the atmospheric pressure drops to saturate the water (solvent) on the surface of the material and evaporate, and is discharged by the vacuum pump in time.