Yingtai Freeze-Drying Tips: Why Does The Vacuum Control Solenoid Valve Make A "Click-Click-Click" Sound?

Yingtai Freeze-Drying Tips: Why Does the Vacuum Control Solenoid Valve Make a "Click-Click-Click" Sound?

1. Is it normal for the vacuum control solenoid valve to make a "click-click-click" sound during the normal operation of a freeze dryer?

Yes, it is normal.

2. Why?

Freeze-drying requires an appropriate vacuum environment. It’s not always better to have a higher vacuum (lower pressure)! Controlling the correct vacuum level ensures effective freeze-drying.

The Yingtai freeze dryer is equipped with a vacuum control feature. During the freeze-drying process, the vacuum pump continuously operates to remove air from the chamber. When the pressure falls below the set point, the vacuum control solenoid valve closes, reducing the exhaust from the chamber. As water sublimates from the sample, the pressure inside the chamber rises. The solenoid valve then opens to release the excess pressure.

Thus, throughout the drying process, the chamber intermittently exhausts, creating the "click-click-click" sound.

3. Summary

Pursuing excessively high vacuum levels is counterproductive and only prolongs the freeze-drying time. Properly controlling the vacuum level during the freeze-drying process not only prevents sample melting but also speeds up the process. Freeze-drying is not just about removing moisture but managing the process effectively.