The vacuum dryer system consists of a refrigeration system, a vacuum system, a heating system, and an electrical instrument control system. The main components are drying oven, condenser, refrigeration unit, vacuum pump, heating/cooling device, etc. Its working principle is to freeze the dried item below the triple point temperature, and then under vacuum conditions, the solid water (ice) in the item is directly sublimated into water vapor, which is removed from the item to dry it. After pre-treatment, the materials are sent to the quick freezing warehouse for freezing, then sent to the drying warehouse for sublimation and dehydration, and finally packaged in the post-processing workshop. The vacuum system establishes low-pressure conditions 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 drying chamber.

The equipment adopts radiation heating, and the material is uniformly heated; Adopting a water trap and capable of achieving rapid defrosting; Adopting a vacuum unit and capable of achieving oil-water separation; Adopting a parallel centralized refrigeration system, with multiple on-demand cooling channels, stable operating conditions, and favorable energy-saving benefits; Adopting artificial intelligence control, with high control accuracy and easy operation. The quality requirements for freeze-dried products are: unchanged biological activity, uniform appearance and color, full shape, firm structure, fast dissolution rate, and low residual moisture. To obtain high-quality products, one should have a comprehensive understanding of the theory and process of freeze-drying.

The freeze-drying vacuum drying process includes three stages: pre freezing, sublimation, and re freeze-drying. Reasonably and effectively shortening the freeze-drying cycle has significant economic value in industrial production. The vacuum dryer introduces thermal energy (such as hot water, low-pressure steam, or thermal oil) into the sealed interlayer, and the heat is transferred from the inner shell to the dried material. Under the power drive, the tank rotates slowly, and the materials inside the tank continuously mix, thereby achieving the purpose of enhancing drying. The material is in a vacuum state, and the decrease in atmospheric pressure causes the water (solvent) on the surface of the material to reach saturation and evaporate, which is promptly discharged by the vacuum pump.

The moisture (solvent) inside the material continuously permeates, evaporates, and is discharged from the surface, and these three processes are carried out continuously. The material achieves the purpose of drying in a very short time. The equipment mainly consists of a cylinder and frame, hollow heating plates of different sizes, a spindle, cross arms and rake blades, a disc feeder, a discharge tray and finished product outlet, an exhaust outlet, heat carrier inlet and outlet pipes, inspection doors, worm gear reducers, continuously variable transmissions, and motors. The main component of the equipment is a hollow heating plate, which is reinforced with a baffle welded to the hollow part. This not only increases the stiffness and strength, but also improves the heat transfer effect, giving full play to the advantage of high utilization of conductive drying heat energy.