The daily maintenance and upkeep of freeze-drying machines are crucial for ensuring stable equipment performance, prolonging service life, and guaranteeing the quality of freeze-dried products. The following are specific maintenance points and operation suggestions:

1、 Check before daily use

Appearance and environmental inspection

Ensure that the surface of the equipment is clean, free from dust and debris accumulation, especially the heat dissipation ports and ventilation holes, to avoid affecting heat dissipation.

Check if the equipment is placed smoothly, the power connection is secure, and the ambient temperature (recommended ≤ 25 ℃) and humidity (recommended ≤ 60%) meet the requirements.

Pre inspection of key components

Refrigeration system: Observe whether there is any abnormal noise before the compressor runs, and whether the pressure gauge indicates normally (the high and low pressure gauges should be balanced in the shutdown state).

Vacuum system: Check whether the oil level of the vacuum pump is within the range of the scale line (if insufficient, add the specified model of vacuum pump oil), and whether the oil quality is emulsified or discolored (if it deteriorates, replace it in a timely manner).

Water trap (cold trap): Confirm that there is no ice residue inside the cold trap (if there is, defrost it first), and that the inner wall is clean and free of foreign objects.

Pipeline and valves: Check whether the connecting pipelines are loose or leaking, and whether the valve switches are flexible.

2、 Key maintenance points during operation

Refrigeration system monitoring

Pay attention to the operating temperature of the compressor (the shell temperature is not hot to the touch during normal operation, and if it overheats, the machine should be stopped to check the heat dissipation), and whether the cooling fan is running normally.

Has the time for the cold trap temperature to reach the standard been extended? (If the cold trap temperature cannot be reduced to below -40 ℃, it may be due to refrigerant leakage or heat exchanger blockage, which requires professional maintenance).

Vacuum system maintenance

Observe whether the vacuum degree is stable during the vacuum pumping process: If the vacuum degree decreases slowly or cannot reach the set value (such as<10Pa), there may be pipeline leakage or a decrease in vacuum pump performance. It is necessary to check the leakage points section by section or replace the pump oil.

Avoid the vacuum pump from sucking in water vapor, organic solvents, or particulate impurities (cold traps or filtration devices can be installed) to prevent oil contamination and pump body damage.

Sample and Freeze Drying Process Management

The loading capacity of materials should not exceed 2/3 of the pallet capacity to avoid excessive accumulation that affects the efficiency of freeze-drying; If it is a liquid sample, it needs to be frozen into a solid state before being placed in the freeze-drying chamber.

During the freeze-drying process, avoid opening the doors frequently to prevent air from entering and causing fluctuations in vacuum level or rapid frosting of the cold trap.

3、 Maintenance operations after shutdown

Cleaning and defrosting

Freeze drying chamber: Use a soft cloth or sponge dipped in neutral cleaning agent (such as soapy water) to wipe the inner wall, avoiding the use of corrosive solvents; If any samples are spilled, they should be promptly removed and disinfected.

Cold trap defrosting: After stopping the machine, wait for the temperature of the cold trap to rise above 0 ℃, use a plastic scraper (not metal tools) to remove frost, dry accumulated water with a water absorbing cloth, and keep the interior dry.

Vacuum pump maintenance:

Before long-term shutdown, run the vacuum pump for 30 minutes (without load) to remove water and impurities from the pump and prevent oil emulsification.

If the pump oil is severely contaminated, it needs to be replaced with new oil (replacement steps: start running for 5 minutes, then stop the machine, release the old oil while it is hot, add new oil to flush the pump chamber, and then inject new oil to the standard oil level).

Moisture and rust prevention treatment

When the machine is shut down for a long time, it is recommended to start it up regularly (once a week) or place a desiccant (such as silica gel) in the freeze-drying chamber to prevent the components from getting damp and rusting.

If rust appears on metal parts (such as shelves and bolts), they need to be sanded with fine sandpaper and coated with anti rust oil.

Pipeline and seal inspection

Check whether the sealing ring of the freeze-drying chamber door is aging or deformed (if there are cracks, it should be replaced in a timely manner), and regularly apply a small amount of vacuum grease to maintain elasticity.

Confirm that the condensate pipeline is unobstructed and free from blockages or leaks.