LN Dewar

Kevin McGovern

Kevin McGovern

Joined
Jul 31, 2015
Messages
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I scored one of these on Craigslist for $40: http://www.aervoid.com/804_Dispenser_p/804.htm

I got it for parties, camping, and possibly use as the ultimate beer growler (5 gallons of cold microbrew? Yes Please!). Anyway, I was thinking this might work as a dewar for Liquid nitrogen, with the relief valve on the lid open of course. Then I figured that since it has a spigot at the bottom, it might not be ideal. I do see a good number of Aervoid food carriers that have no valve, for cheap on ebay. From what I understand, a proper LN dewar is basically a vacuum flask, similar to this thing. I know dewars are expensive, and thought this could be a viable option. Thoughts?
 
Nope, won't work. It would be a ball of frost in no time at all. The valve at the bottom would freeze and break off if you touched it and LN would shoot out all over you and your feet - not a good thing to happen.
 
I suspect that they will transfer heat far faster than allowable.

It is one thing to keep ice tea between 35F and 50 F for six hours at an ambient of 80, and another to keep -346 LN for a month or two at the same ambient. If the tea gets warmer, it is just 40-50-60 degree tea. If the LN gets warmer, it becomes nitrogen gas.
 
I'm not too familiar with dewar construction, but from what I could research, they seam to mostly be a stainless steel vacuum vessel. maybe the vacuum is stronger, or there is additional insulation?
 
There is a pretty big gap between walls and the walls are joined by a large length of non thermally conductive materials that is compatible with cryogenic temperatures. The cap telescopes in about 5 inches with an insulator.

I would be very concerned with a container not designed for the low temperatures. A failure resulting into a spill could be dangerous. Remember, LN is much much colder than boiling water is hot. You want to be careful with it.
 
I hear that. I'm not in the position to be doing cryo yet. I was mostly just interested. I have heard of people getting small quantities in a vacuum thermos, but I assume that is just for immediate transport and use. Thanks for the information.
 
Even if for some reasion it would work I don't think you would find a gas supplier that would fill it with LN.
 
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