The large vacuum freeze-drying machine primarily consists of two parts: the refrigeration system and the vacuum system. Items to be dried are placed in a low-temperature vacuum environment, where the moisture in them is frozen into ice, and then the ice is removed.LowestUnder pressure, the moisture vaporizes and is extracted by a vacuum pump, thereby drying the processed items. If either the refrigeration system or the vacuum system fails, the processing cannot be carried out. Therefore, routine maintenance of the freeze dryer is a crucial task. In the event of a system malfunction, it should be addressed promptly to ensure the normal operation of production. The daily maintenance and maintenance methods for this equipment are as follows::

Maintaining Vacuum Systems

The vacuum system is primarily composed of components such as vacuum pumps, front and rear boxes, valves on the body, mushroom valves, small butterfly valves, and vacuum silicon tubes.Regularly replace the vacuum pump oil to maintain the performance of the vacuum pump.

Before starting the vacuum pump, check if the oil level is normal (it should be around 1/2 of the oil sight glass).

Ensure the rear compartment is dry before vacuuming the box to prevent moisture from being drawn into the pump, which may affect the vacuum pump's suction efficiency.

Large Direct Air Freezing Drying Machine Cold System Maintenance and Repair

The refrigeration system of the freeze-dryer mainly consists of components such as the compressor, expansion valve, water-cooled condenser, evaporator, oil separator, gas-liquid separator, solenoid valve, manual valve, pressure gauge, pressure controller, and drying filter. The main points of daily maintenance include the following::

1) Daily Routine Inspections. The main checks include: ① Whether all valves that should be opened are open.

② Is the pressure of the compressor within the normal range? ③ Are the pressure and temperature of the cooling water normal? ④ Is the return oil from the compressor and the oil level normal? ⑤ Is the operating sound of the compressor normal? ⑥ Is there any abnormal vibration in the refrigeration piping? ⑦ The frosting conditions of the compressor and expansion valve, etc.

Discovered anomalies during inspection; identify the causes promptly, address them immediately, and eliminate potential hazards.

2) When large vacuum freeze-drying machines are not used for an extended period, the refrigerant should be stored in the condenser to prevent leaks. During the production process, it is essential to regularly check for leaks in the refrigeration system to ensure timely detection and handling of any leaks, including if the refrigerant is insufficient. Refills should be made promptly to avoid affecting the normal operation of the equipment.