Vacuum Dryer Machinery Application
Generally, the upper layers are heated by low pressure saturated steam or hot water, hot oil in series, parallel or in series and parallel. There are heat carrier inlet and outlet pipes on each heating plate. Control the temperature of each layer; and the bottom two layers are fed with cooling water to reduce the product temperature, recover heat and ensure quality.
The three processes are carried out from time to time, and the water (solvent) in the material permeates, evaporates and discharges to the surface from time to time. The equipment for drying materials in a very short time mainly consists of cylinder and frame, hollow heating disc, spindle, cross arm and rake blade, disc feeder, disc feeder, disc and finished product outlet, exhaust inlet, heat carrier inlet and outlet pipe, inspection door, worm gear reducer, stepless transmission and motor. The main component of the equipment is hollow heating disc. The hollow part is welded with baffle diaphragm, which not only increases the stiffness and strength, but also improves the heat transfer effect. The advantages of high utilization rate of heat energy in conduction drying are brought into play.
Continuous vacuum dryer
Freeze-drying is a technology that uses sublimation principle to freeze dried substances at low temperature. Then the frozen water molecule is sublimated directly into the process of water vapor escaping under appropriate vacuum environment. The products obtained by freeze drying are called freeze drying substances, and the condensation process does not occur due to dehydration. The side effects such as froth and oxidation caused by steam are prevented. Dry substances are porous like dry sponges, and their volume is basically unchanged. They are easily soluble in water and recover to their original state. Prevent physical, chemical and biological denaturation of drying substances to the greatest extent. Material is always in a low temperature (freezing state) before drying, and ice crystals are evenly distributed in the material.
Generally, the upper layers are heated by low pressure saturated steam or hot water, hot oil in series, parallel or in series and parallel. There are heat carrier inlet and outlet pipes on each heating plate. Control the temperature of each layer; and the bottom two layers are fed with cooling water to reduce the product temperature, recover heat and ensure quality. The heating disc is fixed on the cylinder frame at a certain distance and is placed horizontally. Each layer is equipped with cross booms. The upper and lower layers are staggered 45 degrees and fixed on the central spindle. Driven by worm gear reducer, CVT and motor, the heating disc rotates slowly in 0.6-3.7r/min. Each boom is equipped with a plurality of removable plough-shaped rake blades or flat scrapers arranged at equal distances. The rake blade adopts articulation and spring swing structure, so that its bottom edge can float on the disc surface occasionally, and the rake blade angle can be adjusted arbitrarily according to the material properties to ensure that the material advances on the disc surface from time to time.
Under the mechanical action of the rotary rake blade, the dried material is continuously added from the top disc feeder to the inner ring disk of the top first layer small heating plate in the equipment. While rolling and stirring, moving forward from inside to outside from time to time, jagged all over the disk surface to get contact heating and drying; then the material falls from the outer edge to the bottom of the second layer of large heating disk, under the action of the reverse installed rake blade, and then moves sequentially from outside to inside to the inner edge, falling to the inner ring of the third layer of small heating disk. By analogy, the material moves from top to bottom layer by layer and is heated and dried continuously.
Finally, the dry material falls on the lower plate, and the evaporated moisture is mixed with the exhaust gas in the equipment and discharged naturally from the upper inlet. The rake blade is scraped and discharged continuously from the bottom discharging outlet to obtain qualified dry waste products. According to product performance, drying requirement and disposal quantity, the plate dryer adopts a series of measures, such as spindle stepless speed regulation, manual adjustment of the height of the adjusting sleeve of the disc feeder, control of the temperature distribution of the heating discs in each layer, final cooling and cooling, to give full play to the superior performance of the plate dryer.
Microwave vacuum dryer
Then the solid water (ice) in the product is sublimated directly into water vapor under vacuum condition. The vacuum dryer system consists of refrigeration system, vacuum system, heating system and electrical instrument control system. The main components are drying box, condenser, refrigeration unit, vacuum pump, heating/cooling device, etc. The working principle is to freeze the dried goods below three-phase temperature. Remove from articles to dry them. After pretreatment, the material is frozen in the quick-freezing bin, sublimated and dehydrated in the drying bin, and then packed in the Post-disposal workshop. Vacuum system establishes low pressure condition for sublimation drying bin, heating system provides sublimation latent heat for material, refrigeration system provides cooling capacity for cold trap and drying chamber.
Material is uniformly heated; high efficiency water catching cold trap and high efficiency radiation heating equipment are adopted. It can also realize quick defrosting, high-efficiency vacuum unit and oil-water separation, parallel centralized refrigeration system, multi-channel on-demand cooling, stable working conditions, conducive to energy saving, artificial intelligence control, high control accuracy and easy operation. The quality requirements of freeze-dried products are the same biological activity, uniform appearance, full shape, firm structure, fast dissolution and low residual moisture. In order to obtain high quality products, we should have a comprehensive understanding of the theory and technology of freeze-drying.
The tank is rotated slowly, and the freeze-drying vacuum drying process includes three stages: pre-freezing, sublimation and re-freeze-drying. Reasonable and effective shortening of freeze-drying cycle has obvious economic value in industrial production. The vacuum dryer passes heat from heat sources (such as hot water, low pressure steam or heat conducting oil) into the sealed interlayer to transfer heat from the inner shell to the dried material. Driven by power. Material in the tank is mixed from time to time to achieve the purpose of strengthening drying. Material is in a vacuum state. The water (solvent) on the surface of the material evaporates when the atmospheric pressure drops, and is discharged by the vacuum pump in time.