Maintenance and repair of food freeze dryer

　　We all know that the maintenance and repair of a food freeze dryer consists of two main parts: the refrigeration system and the vacuum system. The principle is that when the object being processed is placed in a low-temperature vacuum environment, the water it contains is frozen into ice, which sublimates into water vapor under low pressure and is pumped out by a vacuum pump to dry the processed object. So we can draw a conclusion that the refrigeration system and vacuum system are the maintenance and repair of food freeze dryers, as well as the brain. As long as one of them has a problem, they cannot function and work properly. Therefore, daily maintenance and upkeep of the freeze dryer is a crucial task. So we need to regularly maintain and upkeep the food freeze dryer, so this time we will further explain the maintenance work for these two systems.

　　1、 Maintenance and upkeep of refrigeration system

　　The refrigeration system of a freeze dryer mainly consists of a compressor, expansion valve, water-cooled condenser, evaporator, oil separator, gas-liquid separator, solenoid valve, manual valve, pressure gauge, pressure controller, drying filter and other parts.

　　The main contents of daily maintenance include the following:

　　1. Daily routine check. The main inspection contents include:

　　2. Are all valves that should be opened open.

　　3. Is the pressure of the compressor within the normal range.

　　4. Is the pressure and temperature of the cooling water normal.

　　5. Is the compressor's return oil and oil level normal.

　　6. Is the sound of the compressor running normal.

　　7. Is there any abnormal vibration in the refrigeration pipeline.

　　8. Frost formation on compressors and expansion valves, etc.

　　9. If any abnormal situation is found during the inspection, the cause should be identified and dealt with in a timely manner to eliminate potential safety hazards.

　　10. When the equipment is not used for a long time, the refrigerant should be stored in the condenser to prevent refrigerant leakage. During the production process, the refrigeration system should be regularly checked for leaks to ensure that any leaks are promptly addressed. If the refrigerant is insufficient, it should be promptly filled to avoid affecting the normal operation of the equipment.

　　2、 Maintenance and upkeep of vacuum system

　　The vacuum system mainly consists of vacuum pump, front box, rear box, valves on the box body, mushroom valve, small butterfly valve, vacuum silicon tube and other parts.

　　1. Regularly replace the vacuum pump oil to ensure the performance of the vacuum pump.

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

　　3. Before vacuuming the box, it is necessary to ensure that the back box is dry to avoid pumping water vapor into the pump body, which may affect the pumping efficiency of the vacuum pump.

　　4. Nowadays, freeze-drying machines are used in many fields of drying. As a new type of drying method, there is no doubt that the maintenance and repair of food freeze-drying machines have good drying effects. Due to the retention of material components and the effect of later storage and rehydration, freeze-drying can achieve almost perfect preservation of the original material properties.

　　5. The maintenance and repair of food freeze dryers mainly consist of electronic control systems, refrigeration systems, vacuum systems, and some spare parts. Let's first talk about some maintenance of the vacuum system:

　　6. The vacuum system is one of the important components of the maintenance and repair of food freeze dryers, generally including rotary vane vacuum pumps or dry pumps and Roots pumps for accelerated vacuum pumping.

　　7. Last time I talked about the inspection of the vacuum pump during operation, this time I will explain the inspection and maintenance of the vacuum system of the freeze dryer that has been out of service for a long time.

　　3、 Maintenance and upkeep of vacuum pumps

　　1. If the pump is not used for a period of time, the power and cooling water supply should be turned off;

　　2. If the pump is directly turned off after the freeze-drying process is completed, water vapor may remain in the pump body. If the pump is kept in a closed state for a long time, these liquids may corrode the mechanical structure of the pump, which may cause the pump to be unable to start again. It is recommended that the pump run idle for about half an hour after debugging is completed.

　　3. The pump head valve is powered on simultaneously when the vacuum pump is turned on, and powered off when the vacuum pump is stopped;

　　4. The power supply of the pump head valve can be determined from the air inlet at the end of the valve. Remove the muffler, block the air inlet with your hand, and if there is air sucked in, it proves that the valve is not powered, otherwise it is powered;

　　5. Turn off the vacuum pump and cut off the power supply of the pump head valve. Determine whether the pump head valve is tightly closed by the change in vacuum degree of the silicon tube on the vacuum tube.

　　We have briefly introduced the maintenance and repair of food freeze dryers here. If you need more information, please contact our staff.

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