Can anyone provide us guide for removal of ice blockage inside the helium refill duct. Today, we tried to refill our liquid helium, but before we did that, we use the gauge to measure how much helium left inside the dewar, but the duct was blocked, and we could not insert the stainless tube inside the duct. Then we used the helium gas to blow the duct for half hour, we still could not remove the blockage. Therefore, we stopped our helium refilling after wasting more than 2 hours.
We believed that the helium might have been covered by a layer of ice, and when helium was transferred into the dewar, it simply bypassed the dewar and got out of the dewar from other outlet.
Any guide or hint will be greatly appreciated!
Best wishes,
Daniel
From: Xianbin Yang <xianbin.yang_at_thioaptamer.com<mailto:xianbin.yang_at_thioaptamer.com>>
Date: Tuesday, March 31, 2015 at 9:43 PM
To: "Bui, Lien" <bui_at_uhcl.edu<mailto:bui_at_uhcl.edu>>, Zerong_Wang <wang_at_uhcl.edu<mailto:wang_at_uhcl.edu>>, "Rohde, Larry" <Rohde_at_uhcl.edu<mailto:Rohde_at_uhcl.edu>>
Cc: 'Anton Dubrovskiy' <anton.dubrovskiy_at_gmail.com<mailto:anton.dubrovskiy_at_gmail.com>>
Subject: [Possible Spam: 10%] RE: Refilling He today 03-31_2015
Today I arrived at the NMR room at 5:35 pm and called Anton to refill the helium as usual. However, I can not use the “tool” (used for measuring the height of the remaining Helium level within the magnet) and go through the “throat” of the magnet to reach the level of the helium. This means that the “throat” was blocked. Thus we can not refill any liquid helium. Therefore, we introduce helium gas with the hope to make it work. After about 30 min, the blockage is still existing! Then we tried to refill the liquid helium for about 20 min, we hoped that we could make it work. Both Anton and I tried the “tool” to go through the “throat”, again. We failed.
Xianbin
Received on Tue Mar 31 2015 - 17:20:35 MST