AMMRLers:
Do you ever think about what you would do if the only elevator in your
building was broken for a month? Well, I have thought about it, and now
have an opportunity to put those thoughts into action.
Our facility is in the basement, with access only via stairs or an
elevator. Our 40 year old elevator died, there are no repair parts
available, and bespoke parts will take several weeks to fabricate.
The first week, we bumped a 180 liter dewar down the stairs. This
required several large, strong people, and they didn't want to do it
again. Our safety officer rejected the idea of rubber hose going down
the stairs.
Our solution was to purchase a 30 foot long cryoline, and run it through
a hole in the facility ceiling. (For reasons unknown, there is a hole
covered by a hatch in the ceiling/floor of a research lab. The hole is
directly under a safety shower, which, fortunately, has never been used.)
We were told that the line was non-magnetic. We verified this before
running it across the lab.
The first time we used it, the line took about 30 minutes to start
delivering liquid. We then stored it overnight in a -80 freezer. Now
it only takes about 5-10 minutes to cool down, and once cooled down, the
line transfers pretty efficiently. We estimate that we are only losing
20% or so above normal. We run liquid turning to gas nitrogen through
the line until liquid comes out. Then we stop the transfer, insert the
line into the magnet or dewar, and turn it back on. This way, we are not
blowing liquid out of the magnets. This also clears out the line.
Pictures, or it didn't happen:
http://nmr.unm.edu/nitrogen.html
kas
--
Karen Ann Smith Director, NMR Facility
Group Leader, Analytical Chemistry Services
Department of Chemistry and Chemical Biology
Clark Hall MSC03 2060
1 University of New Mexico Albuquerque, NM 87131-0001
karenann_at_unm.edu 505.277.4031 http://nmr.unm.edu
Out of this world screensaver: http://setiathome.ssl.berkeley.edu
"There is nothing a good day of cycling won't cure."
Received on Fri Apr 06 2018 - 09:25:17 MST