Resonators;
For the second time in less than 6 months, we have had to abandon the
liquid nitrogen refill of the prodigy dewar. As happened last fall, the
nitrogen gas out port is clogged or blocked. Nothing comes out, which
means that the overpressure valve is triggered as soon as we try to put
liquid nitrogen in.
Last time this happened, Bruker said to:
warm up the probe
disconnect all hoses from the dewar
dump out any remaining nitrogen
warm up the dewar completely
Then, re-connect all hoses, refill the dewar, and cool the probe. This
results in over 24 hours of down time.
I tried running a hose with nitrogen gas into the out port. It will go
in about 6 inches before it hits something. I don't know if that is ice
or a baffle.
Does anyone have any suggestions that don't involve a day of down time?
Does anyone have any suggestions of how to prevent this from happening?
(My TA runs gas thru the fill line, unscrews the black caps, puts the
vent hose on the out, runs a bit more nitrogen, then attaches the fill
line.) The out line is only open for a few seconds.
thanks,
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
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Received on Thu Feb 15 2018 - 08:48:03 MST