Dear AMMRLers,
I received a lot of helpful information about the "bag-less + medium pressu=
re storage" solution for He recovery. I thought I could summarize here it for
everyone.
(note: I was mainly looking for important different to the (seemingly) more
widespread "balloon" strategy.)
I got replies from Halifax, Alberta, Syracuse, Guelph, Nebraska, Virginia,
McGill, Columbia, Oklahoma, North Carolina, Memphis who all have or plan to
have a bag-less setup either from Quantum Technologies (QT) or Quantum Design (QD).
All those replies are from North America which proves that this solution is not
so widespread in Europe (although it might reflect a North American bias of the
ammrl?).
So here are some my take-home messages:
-The customer satisfaction is generally high throughout...
-"works well", "happy", etc.
-Each NMR lab is unique and the companies will help find cu=
stomized solution
-Friendly support although sometimes spotty and slow.
-Although companies states recovery potential up to 95%, the actual recovery
ranges from 65-92%.
-The main advantages are:
-smaller footprint,
-less expensive,
-less contamination,
-recovery dewar=fill dewar.
-Some disadvantages:
-liquefier runs 24/7,
-lower recovery,
-the "medium pressure" compressor/storage can reach its limits during fast/long fills,
-one person mentioned NMR measurement instabilities because magnets sense back-pressure.
-Other things to pay attention to (not sure these are disadvantages compared to
the balloon system):
-patience requires! long learning curve to get optimal recovery!
-requires at least 4-5h of maintenance work per week.
-special attention for pumped magnets (by-pass during fills to
avoid alarms?)
-get a He-leak detector! (Suggested: https://www.restek.com/p/28500
-carefully plan your magnet boil-off hook-ups (by knowledgeable people)
to avoid back-pressure instabilities
That's pretty much it. Thanks to all who took the time to share their exper=
ience!
Best regards
Christophe
> From: Fares, Christophe
> Sent: Sunday, January 28, 2024 21:09
> To: 'main_at_ammrl.groups.io' <main_at_ammrl.groups.io>
> Subject: "bag-less" helium-recovery
Dear Community,
I was wondering if there is anyone out there willing to share their experience
with the He-recovery systems like the one from Quantum Technologies (Picasso/ "All-metal")
---- or similar? --- which have the characteristic feature that they works without a
"balloon" to collect He. Instead, the He boil-off is directly purified and re-liquefied.
In case of high flow (eg. during fills), a compressor switches on and stores excess
flow to a medium pressure container for later recovery. The advantages are the
smaller space requirements and the helium reaching the purifier less contaminated.
But perhaps there are obvious downsides which I am not seeing, especially since this
solution does not seem to be widespread.
Best regards
Chris
---------------------------------------------------
Christophe Farès, Ph.D.
---------------------------------------------------
NMR Department/NMR Abteilung
Max-Planck Institut für Kohlenforschung
Kaiser-Wilhelm Platz 1
45470 Mülheim an der Ruhr
Tel: +49 208 306 2130
E-mail: fares [a] mpi-muelheim [.] mpg [.] de
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Received on Mon Feb 05 2024 - 00:35:25 MST