Freeze-drying is to use the principle of sublimation drying of a technique is to dry the material at low temperatures, rapid freezing, and then in a vacuum environment, the direct sublimation of frozen water molecules as water vapor escape. Frozen drying the product obtained is known as freeze-dried material (lyophilizer), the process known as freeze-dried (lyophilization). Material before drying, remains low temperatures (frozen), ice crystals at the same time uniform distribution of material in the sublimation process does not concentrate phenomenon occurs due to dehydration, to avoid the bubble, oxidation and other side effects generated by the steam. The dry material was dry sponge porous volume is essentially the same, easily soluble in water and restitution. The maximum extent possible to prevent the degeneration of the dry material physics and chemistry and biology.
The freeze-dried vacuum drying process, including pre-freezing, sublimation, and then freeze-dried three phased. Reasonable and effective to shorten the freeze-dried cycles in industrial production has significant economic value. Vacuum Dryer pass into thermal energy (such as hot water, low pressure steam or hot oil) in a sealed sandwich pass was dry materials, the heat within the shell. Under driving of power, the tank slowly rotating the tank material constantly mixed so as to achieve the purpose of reinforced drying. Material in a vacuum, atmospheric pressure down the material surface of the water (solvent) to reach saturation, evaporation, and promptly eliminated by the vacuum pump.
Materials within the water (solvent) continue to penetrate to the surface, evaporation, discharge, three processes are ongoing, the material in a very short period of time to achieve the purpose of drying. Set up
Import and export of pipe layers heated plate on both the heat carrier, generally the upper layers of the low-pressure saturated steam or hot water, hot oil, in series, parallel or series-parallel input heating, control the layers of temperature; the bottom of the second floor which leads to the cooling water. to reduce the product temperature, heat recovery, and ensure quality. Heating coil according to a certain pitch is fixed to the cylinder frame, showing the level of placement, during which each floor are equipped with a cross arm support, upper and lower levels of dislocation 45 ° staggered fixed on the center spindle and worm gear reducer, CVT and motor drive slowly turning to 0.6 ~ 3.7 (r / min). Support each boom tops have removable plow-shaped rake leaves or flat scraper, was equidistant arrangement. Rake leaves articulated and reed swing structure, so that the bottom edge on the disc with dual float and can be adjusted according to the material traits angle of rake leaves to ensure that the material in the disk is constantly advancing. Dry material from the top of the disc feeder continuously added to the equipment within the top layer of small heating coil on the inner disk, the mechanical action of the rotary rake leaves, while tumbling mixing, one side from the inside out, forward movement was jagged covered the entire disk, the contact with the heating and drying; material from the outer edge of the drop to the outer disk of the second layer below the heating coil, rake leaves under the action of reverse-mount, and from the outside in sequential moved to the inner edge, and fell on the third floor of a small heating coil inner disk. And so on, so that the material layer by layer from top to bottom layer mobile continuous heating and drying. Evaporation of moisture and equipment exhaust mixing from the upper outlet of the natural discharge, the final dry material to fall into the footwall, rake leaves blew into continuous discharge in the bottom of the discharge port, access to qualified dry finished. Based on product performance, the size of the drying requirements and processing capacity, plate dryer with spindles stepless manual adjustment disc feeder adjustment sets the height of the control layers of the heating plate temperature distribution and a final cooling down a series of measures have played a superior performance of the plate dryer.
Vacuum Dryer - mechanical use of microwave vacuum dryer
Vacuum dryer by refrigeration system, vacuum system, heating system, electrical and instrumentation control systems. The main components of the oven, condenser, cooling unit, vacuum pump, heating / cooling device. It works by first freeze dry items will be below the triple point temperature, the items in the solid water (ice) and then under vacuum condition to sublimate directly into water vapor, to exclude from the article, so that dry goods. Materials are processed into frozen positions to freeze, and then into the sublimation of dry warehouse, followed by post-processing workshop packaging. Vacuum system for lyophilization positions to establish the conditions of low pressure, the heating system to provide materials with latent heat of sublimation, the refrigeration system to the cold trap and the drying chamber to provide the required cooling capacity.
Freeze-drying equipment with efficient radiant heating, the material is heated evenly; efficient capture of the water-cooled trap, and to achieve rapid defrosting; efficient vacuum unit, and can realize the oil-water separator; parallel centralized cooling system, multi-channel on-demand cooling, industrial stable conditions conducive to energy conservation; artificial intelligence, control, control of high precision, easy to operate. The quality requirements of the freeze-dried products: biological activity of the same uniform appearance and color, full shape, solid structure, fast dissolving, low residual moisture. To obtain high-quality products, there should be a more comprehensive understanding of the theory and technology of the freeze-dried.
Freeze-drying equipment import and export by the cylinder and framework, the size of the hollow heat the disk, spindle, cross arm and rake leaves, disc feeding device, the cutting plate and the export of finished products, exhaust outlet, the heat carrier tube to view the door, worm gear reducer continuously variable transmission and motor. The main components of the device is hollow heating coil, hollow Ministry of welded baffle bulkhead to strengthen, both to increase the stiffness and strength, but also improves the heat transfer effect, and played a conduction drying the advantages of high utilization of geothermal energy. |
Details of freeze-drying in the drying equipment