The common faults and corresponding troubleshooting methods that may occur during the operation of cosmetic freeze-drying machines can be summarized as follows:

1、 Refrigeration system malfunction

1. Fault phenomenon: Poor cooling effect, unable to reach the set temperature.

Possible reasons:

Insufficient or leaking refrigerant.

Minor blockage of refrigeration system components, such as clogged dry filters.

The evaporator is leaking.

Compressor malfunction, such as loose compressor foot bolts or internal damage to the compressor.

External influences such as high intake temperature, large intake flow rate, and exceeding the rated processing capacity.

2. Exclusion method:

Check if the refrigerant is sufficient, and if there is a leak, leak it and add refrigerant.

Replace the dry filter and clean the impurities in the refrigeration system.

Check if the evaporator is leaking, and if there is a leak, repair or replace the evaporator.

Check if the compressor foot bolts are loose and tighten the bolts; If the compressor is damaged internally, it needs to be replaced.

Adjust the intake temperature and flow rate to ensure they are within the rated processing capacity range.

2、 Vacuum system failure of cosmetic freeze-drying machine

1. Fault phenomenon: The vacuum degree cannot reach the set value or the vacuum pump cannot work normally.

2. Possible reasons:

Vacuum pump oil contamination or insufficient quantity.

The sealing ring of the vacuum valve is aging or damaged.

The temperature of the cold trap is too high, which affects the vacuum degree.

The box is leaking due to aging sealing strips or improper installation.

Vacuum pump malfunction, such as motor damage or water ingress into the pump chamber.

3. Exclusion method:

Replace the vacuum pump oil to ensure that the oil level is within the normal range and the oil quality is clean.

Replace the sealing ring of the vacuum valve to ensure good sealing.

Reduce the temperature of the cold trap to below -50 ℃ and check if the refrigeration system is functioning properly.

Check if the sealing strip of the box is aging or improperly installed, and tighten all connecting bolts; Use a helium mass spectrometer leak detector to detect if there is any air leakage in the box.

Check if the vacuum pump motor is damaged, and replace the motor if it is damaged; If water enters the pump chamber, it is necessary to drain the water and replace the lubricating oil.

3、 Heating system malfunction of cosmetic freeze-drying machine

1. Fault phenomenon: The heating system cannot work properly or the temperature control is inaccurate.

2. Possible reasons:

Heating tube open circuit or poor contact.

The temperature sensor is offset or damaged.

The solid-state relay is damaged or the output signal of the control board is abnormal.

3. Exclusion method:

Use a multimeter to check the resistance of the heating tube. If there is an open circuit or poor contact, replace the heating tube.

Calibrate the temperature sensor and replace it if the error is too large.

Replace the solid-state relay and check if the output signal of the control board is normal.

4、 Control system malfunction of cosmetic freeze-drying machine

1. Fault phenomenon: The control system cannot work properly or displays error messages.

2. Possible reasons:

PLC program logic error or low battery level.

Touch screen communication interruption or damage.

Sensor signal interference or loose wiring.

3. Exclusion method:

After backup, reset the PLC program and replace the battery.

Check if the RS485 communication cable is loose or damaged. If it is damaged, replace the communication cable; If the touch screen is damaged, it needs to be replaced.

Shield the signal lines of the control cabinet and keep them away from interference sources; Tighten the sensor wiring to ensure stable signal transmission.