helium mass spectrometer leak detector in vacuum carburizing furnace
Reasons for leakage detection of vacuum carburizing furnace:
Vacuum carburizing furnace and vacuum cementite furnace are vacuumized by roots pump unit at the end. The vacuum demand reaches 1 x10-3 mbar, and the vacuum works effectively. Due to the temperature of about 900 ℃ under carburizing treatment, if the sealing component is easy to oxidize, it will lead to the premium of the whole furnace and huge loss. Therefore, the sealing of vacuum carburizing furnace is very important, and leakage detection is very important.
Leakage detection method applied to vacuum carburizing furnace:
The helium mass spectrometer leak detector provides two leak detection modes: vacuum mode (vacuum mode) and positive pressure (sniffer mode). The vacuum carburizing furnace uses two kinds of vacuum leak detection detectors: vacuum mode (vacuum mode) and positive pressure (sniffer mode). The helium mass spectrometer leak detector is connected to the vacuum system with a good connection port near the vacuum pump. The vacuum system and the pump group are in the process of vacuumizing, Therefore, the inlet of the pump is connected with the helium mass spectrometer leak detector, which is the flow of air. It is easy to have the segmented helium mass spectrometer leak detector at some points, so as to achieve the impact of leakage detection.
The inlet of the mass spectrometer leak detector is connected to the mechanical pump group. First start the pump group, vacuum carburizing furnace, and then start the helium mass spectrometer leak detector. The corner valve of the mass spectrometer leak detector must be closed. When the vacuum pump set reaches a certain vacuum degree (high back pressure of 25 mbar in the industry), the leakage detection operation can be carried out.
When the vacuum pump unit reaches a certain vacuum degree, the standby helium mass spectrometer leak detector and the corner valve are closed. At this time, you can press start to control the leak detector, the helium mass spectrometer leak detector starts to leak, and then slowly open the angle valve to observe the change value of the leakage rate. Because the leakage detector is connected with the vacuum carburizing furnace chamber and the vacuum degree changes, the leakage rate value also changes, until the steady rate value, Then turn the angle valve slowly, wait for the value to stabilize, and spray helium for leak detection.
After spraying, the helium mass spectrometer leak detector shows that the value of helium leakage rate exceeds the set value, and there are obvious warning sounds, which gather here, and then detect the leakage in other places.
When it is found that the leakage detection and helium enter the vacuum system, the leakage rate value gradually rises. In order to quickly detect the leakage, you can press the zero button to leave on the screen. The background of the leak detector can be found, and then the next collection can be found to save time.