LN2 Scavenger Plates 1

[withiam]

When getting ready to vent a vacuum chamber (2000 cubic feet), when is the best time and/or pressure to shut down the LN2 flow to the Getter/Scavenger Plates?
Is it better to warm the plates prior to venting?
Is better to introduce some atmosphere into the chamber then shut down LN2 flow to the plates?
We use GN2 for venting.

Any reply is appreciated.

withiam

 

[ColdBass]

Hi Withiam,
I think it would be better to stop LIN flow asap. The Getter plates will not thaw out quickly until you intoduce some gas back into the chamber to start convection.
Alternatively if you are using the exhaust N2 gas from teh getters to re-pressurise the chamber it miht make sense to leave the LIN on until you have raised the pressure to atmospheric.
Best Regards
Jerry

 

[withiam]

Jerry,
Thanks for your response. Your advice is appreciated.
We have been activating the plates at 50 Torr while "pumping down" and deactivating the plates during repress at the same pressure (50 Torr).

Withiam