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There can be danger in improperly storing LN if it comes into contact with air, since it will liquefy oxygen. Liquid O2 is a very dangerous thing to have in you
by idlewords 6y ago
There can be danger in improperly storing LN if it comes into contact with air, since it will liquefy oxygen. Liquid O2 is a very dangerous thing to have in your garage.
- tptacek 6y agoHuh, interesting. How would that work with dewar, though? The LN is constantly evaporating and pushing gas out of the container. The garage thing seems like a good point, because, yeah, if there's one place in the world you don't accidentally want to collect liquid oxygen... (goes to move dewar).
- idlewords 6y agoThe typical situation where this happens in a chem lab (where I learned about this stuff) is having glass tubing immersed in a dewar as a vapor trap for a vacuum pump. In normal operation, the tubing has near-vacuum inside, and the liquid nitrogen condenses any volatiles that might get into the vacuum system. But if you open the vacuum system to the air and leave it immersed in the dewar, then you can condense a considerable amount of oxygen in the bottom of the vapor trap... which is already covered in whatever organic gunk you were trapping in the first place. I post this not because I think people keeping a thermos of liquid N2 in their garage need to worry about it, but because it's such a nonobvious way to blow yourself up with what is in all other respects a docile substance.