Freeze dryers play a crucial role in fields such as food processing, pharmaceuticals, and biological research. However, like any complex equipment, freeze-drying machines may also malfunction, and timely and accurate diagnosis of faults is crucial to ensure the smooth progress of production and experiments.
Firstly, make a preliminary judgment based on the running sound. A normally functioning freeze dryer should produce a steady and rhythmic humming sound when the compressor is running, and the flow of refrigerant in the refrigeration system should also be relatively quiet and regular. If abnormal sharp noise is heard, such as metal friction or severe vibration, it is likely to indicate wear of internal parts of the compressor, or resonance in the refrigeration pipeline due to foreign object blockage or deformation. At this time, the machine should be stopped immediately for inspection.
Temperature is also an important criterion for judgment. In the pre freezing stage, if the set freezing temperature cannot be reached for a long time, it may be due to a leakage in the refrigeration system, resulting in insufficient refrigerant, or a decrease in the compressor power of the refrigeration unit, which cannot cool normally. During the sublimation drying process, if the temperature of the heating plate continues to be too high and exceeds the set range, it may be due to a temperature sensor malfunction, which missignals the temperature signal and causes the heating system to lose control; On the contrary, if the temperature cannot rise continuously, it may be due to damage to the heating element or problems with the circuit connection, which affects the transfer of heat.
The change in vacuum degree cannot be ignored either. During the operation of the freeze dryer, the vacuum system needs to maintain a certain degree of vacuum to ensure the smooth sublimation of moisture. If the vacuum degree suddenly drops significantly, it may be due to aging or damage of the sealing gasket, causing a large influx of external air; It may also be due to the performance degradation of the vacuum pump, which cannot effectively extract air. In addition, observing the condenser, if there is uneven or no frost on the surface, it may indicate that the refrigeration cycle is not smooth, there may be refrigerant leakage or refrigeration component failure.
Furthermore, pay attention to the status of the materials. If it is found that the material has not reached the expected drying degree after freeze-drying, in addition to considering the incorrect process parameter settings, it may also be due to poor coordination between the refrigeration and vacuum systems of the freeze-drying machine, which hinders the sublimation process. For example, the temperature of the cold trap is not low enough to fully capture the sublimated water vapor, which affects the overall freeze-drying effect.
In addition, faults in the electrical system may also cause a series of problems. If there are garbled characters or unresponsive buttons on the display screen, it may be due to damage to electronic components on the control circuit board, or a short circuit or open circuit in the wiring.
In short, by carefully listening to the operating sound, monitoring temperature changes, paying attention to vacuum fluctuations, checking material status, and troubleshooting electrical systems, comprehensive judgments can be made to accurately identify faults in the freeze-drying machine, so as to take corresponding maintenance measures in a timely manner and ensure the normal operation of the equipment.