I quenched two old (1980’s) smaller (300 and 100 MHz) magnets over
the holiday break last year to make sure no one else was around. I stopped
filling Nitrogen in late November and just allowed the magnets to run out of
Helium. They quenched just before New Years. It took 2-3 weeks more to let
them warm up completely and they were finally disposed of in early February.
We chose this rather brutal method because they were the only magnets in the
lab. No one else was allowed inside the lab for the whole of December and
“No-Entry” signs were posted at the lab door.
If you have more NMRs in your lab and there are people working on them every
day, it might be better to have someone come in and deenergize it safely.
Best Regards,
Jürgen
_______________________________________________
Jürgen Schulte, Ph. D.
NMR Specialist =
Binghamton University
SN Building, RM 1024
25 Murray Hill Road
Vestal, NY 13850
Ph.: 607-777-4405
Fax: 607-777-4478
<mailto:schulte_at_binghamton.edu> schulte_at_binghamton.edu
http://nmr.binghamton.edu/Schulte.html
> From: main_at_ammrl.groups.io <main_at_ammrl.groups.io> On Behalf Of Anne-Frances Miller
> Sent: Wednesday, December 6, 2023 4:46 PM
> To: main_at_ammrl.groups.io
> Cc: Anne-Frances Miller <afmill3r2_at_gmail.com>
> Subject: [External Email] [AMMRL] planning to decommision a magnet that is too old to refurbish or give away
Dear AMMRL,
We have a very old round-bottom 600 MHz magnet from 1999 that I am told can
no longer be refurbished with any warranty, yet it is becoming too costly
to keep filled. Therefore I am planning to quench it, but want to do so safely.
Do any of you know of ‘instruction sheets' or guidelines available
for this rare procedure?
In case you are willing to comment and correct, I will appreciate it:
my plan is to allow the He level to come down to ≈35% while keeping up with N2 fills.
Remove all the hardware that is not related to the magnet itself (e.g. probe etc, lower the legs).
Remove the sealing caps on the tops of the lHe reservoir and lN2 reservoir so that there are
unobstructed exit paths.
Attach a gaseous He tank to the port of the dewar vacuum space, with a low pressure of He via a
needle valve (and of course a regulator).
Crack open the valve on the vacuum space to admit He gas. (I could also fill a large ‘bottle'
with He gas and connect that, instead of a regulated cylinder.)
Promptly back away to a safe distance with good ventilation.
Many Thanks in advance,
and I will know that no advice provided mades the provider legally responsible,
Anne-Frances
Novel Meritorious Research (and teaching)
—•—•—•—•=
•—•—•—•=
•—•—•—•—=
•—
A.-F. Miller, Ph. D. (she/elle/sie)
University Research Professor
Professor of Chemistry
University of Kentucky
https://www.uky.edu/*afm/
Visiting Fellow,
Einstein Foundation of Berlin
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Received on Thu Dec 07 2023 - 06:06:47 MST