The machine of Freeze Dried Fruit Machine is composed of refrigeration system, vacuum system, heating system and electrical instrument control system. The main components are drying cabinet, condenser, freezing unit, vacuum pump, heating/cooling device, etc. Its working principle is to freeze the dried articles below the triple point temperature, and then directly sublimate the solid water (ice) in the articles into water vapor under the vacuum condition, remove it from the articles, and dry the articles. After pretreatment, the materials are sent to a quick freezing bin for freezing, then sent to a drying bin for sublimation and dehydration, and then packaged in a post-treatment workshop. The vacuum system establishes a low-pressure condition for the sublimation drying chamber, the heating system provides latent heat of sublimation to the material, and the refrigeration system provides required cold energy to the cold trap and the drying chamber.
- Use of freezing oil for freeze-drying equipment
Generally speaking, the refrigerant oil should be replaced after 100h hours of operation of the refrigeration system, and after 10,000 ~ 12,000 hours of operation, the refrigerant oil should be replaced as long as the oil level is 1/4 of that of the sight glass. Do not add more oil. Excessive oil will easily cause oil shock. Generally, special refrigerator oil shall be used according to the requirements specified by the manufacturer.
- Replacement of Freezing Oil for Lyophilization Equipment
(1) Close the suction valve of the compressor, manually reset the oil pressure safety controller, start the compressor, and discharge the refrigerant in the compressor into the system. When the pressure in the compressor is balanced with atmospheric pressure, shut down the compressor (cut off the power supply) and close the compressor discharge stop valve. At this time, the pressure in the compressor will rise somewhat. Open the connector on the discharge stop valve to discharge the stored gas.
(2) Screw down the oil plug from the oil drain of the compressor and take out the oil filter to drain the dirty oil.
(3) Wash the metal powder on the oil plug of the oil filter with gasoline, air dry and then reload and tighten the oil drain plug.
(4) Screw off the plug at the top left of the compressor sight glass, connect it with the oil barrel with an oil filling pipe, vacuumize the compressor, and the refrigerant oil is automatically sucked into the compressor under the action of atmospheric pressure.
(5) The oil change amount should only be 1/4 of the oil sight glass exposed, and then screw on the plug.
(6) Use a vacuum pump to pump out the air in the compressor.
(7) Open the compressor suction and discharge stop valve to put the compressor into operation.