The device in the video is apparently only warming up the gas in the top of the dewar by allowing it to escape into the bag, then pushing it back in. Without some very careful procedure to attach, remove, and store the bag and tubing, there will certainly be air introduced to the dewar. IMO contamination is guaranteed with this device.
Cheers, -Hirsch
From: Manoj Naik [mailto:manonaik_at_gmail.com]
Sent: Wednesday, October 08, 2014 2:59 AM
To: Matthias Findeisen; AMMRL_at_ammrl.org
Subject: Re: AMMRL: Helium Gas Specification for Refilling Purpose
Dear Mathias,
Please check the link below for images & video clip of a device to pressurize the Helium container. It require to paddle up (please see the video clip) several time to build the pressure in a Helium container, which may be not that convenient as that of Helium gas cylinder, but it make Helium gas cylinder redundent. Free of impurity concern & saving a inventory of Helium gas cynlider.
https://plus.google.com/photos/107209094718337103609/albums/6067329649340496785?cfem=1&authkey=CMq-yMyEiomCngE
Hope that this could be a usefull device in NMR lab.
Cheers,
Manoj
On Fri, Oct 3, 2014 at 12:10 AM, Manoj Naik <manonaik_at_gmail.com<mailto:manonaik_at_gmail.com>> wrote:
Dear Mathias,
Helium gas 99.996 is perfectly fine for pressuring Liquid He container.
We had used same grade for more than 10 years.
But since last year we have devised another mechanism to pressurize the container.
We are using Hot water bag(available with chemist shop) with adaptor and Silicon tube to connect it
at the Vent port (where you connect Helium Gas) of Helium container. This bag is sandwich in
wooden folded planks & we paddle it to increase the container pressure. So no more need of Helium Gas cylinder.
Unfortunately, right now I am not able to send you the images & video clip of our device as I am away, but
surely I will share that device with AMMRL community when I will be back to NMR Facility.
Cheers,
Manoj
On Thu, Oct 2, 2014 at 2:59 PM, Matthias Findeisen <matthias.findeisen_at_uni-leipzig.de<mailto:matthias.findeisen_at_uni-leipzig.de>> wrote:
Dear all,
which Helium-Gas Cylinder do you use for refilling the magnet (i.e. to give slight pressure onto the refill dewar)?
Is the specification of 99.996 % sufficient for this?
Which experiences do you have?
Thanks!
Yours
Matthias Findeisen
Univ- Leipzig/ Germany
--
Manoj Vishnu Naik,
NMR Facility,
Tata Institute of Fundamental Research,
Homi Bhabha Road, Colaba,
Mumbai, INDIA-400005
Tel: +91 22 22782525
Fax:+91 22 22804682
--
Manoj Vishnu Naik,
NMR Facility,
Tata Institute of Fundamental Research,
Homi Bhabha Road, Colaba,
Mumbai, INDIA-400005
Tel: +91 22 22782525
Fax:+91 22 22804682
Received on Wed Oct 08 2014 - 10:54:20 MST