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A Liquid Nitrogen Cocktail Party

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Re: A Liquid Nitrogen Cocktail Party

#52

The article warns about the possible hazards, but it's worth reiterating: http://www.theguardian.com/uk/2012/oct/08/teenager-stomach-l...

Was about to post a link to the same thing. As far as dangerous culinary experiences go, the risk if you get it wrong is up there with eating blowfish. Do not be tempted to do this as your first experience in handling liquid nitrogen. Get to know the stuff first.

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Re: A Liquid Nitrogen Cocktail Party

#54
post #50
post #47

I do not want to discourage people from playing with cool stuff, but for safety reasons, I would like to give a few examples of what can go wrong: LN expands by 700x when it evaporates and warms up to room temperature. This makes thermoses inherently unsafe for storing LN, because they come with lids . Human experience, and the lid itself, through its design, say: Put this lid on top of the thermos! If you get carrie…

We did hide the caps for the thermoses. You didn't read that in my post because my post is not an instruction manual. I opted instead to keep it vague, saying instead that sealing LN into a container would kill you. The point of the thermos is to keep a relatively small amount of LN in your workspace, so that the bulk of it can be kept out of the house entirely. The thermos is itself a safety measure.

My lab partner back at university once got a very nasty liquid nitrogen burn. Couldn't use his hand for a few weeks. We even executed emergency procedures swiftly and correctly.

It was a freak accident, but since then I always cringe when I see articles like this that have little mention of the dangers involved and appropriate safety measures.

Re: A Liquid Nitrogen Cocktail Party

#55
post #47

I do not want to discourage people from playing with cool stuff, but for safety reasons, I would like to give a few examples of what can go wrong: LN expands by 700x when it evaporates and warms up to room temperature. This makes thermoses inherently unsafe for storing LN, because they come with lids . Human experience, and the lid itself, through its design, say: Put this lid on top of the thermos! If you get carrie…

It's true, it is easy to get carried away by the fact that the Leidenfrost effect can protect you from small splashes of nitrogen on your skin. As the demos show, it's even possible to dip a BARE hand in... very briefly. For the love of god, don't do this while wearing a ring or a glove.

It's objects that are the problem, because they do not evaporate and they do not flow away. One of the worst is cloth, which tends to be wrapped around your skin, so when it gets soaked in LN it promptly gets super cold and then sits there burning you while you try to get it off. I got a tiny splash on one of my socks once. Fortunately it wasn't a big enough splash to do more than sting a lot and teach me never to splash LN on my clothing again.

And, as you point out, the other problem is that protective gloves are essential for handling cold solid objects, but very dangerous to have on your hands when touching the liquid. Which means you need tongs! Long tongs, so that your gloved hand stays safely at one end while the other end is fishing around in the nitrogen.

Re: A Liquid Nitrogen Cocktail Party

#56
post #46

Not enough good is being said about Cooking Issues and Dave Arnold in the comments on HN. If you don't know the podcast, then you've got about 160 hours of catching up to do. Dave is a better hacker than you.

Exactly. And the Searzall proves it. https://www.kickstarter.com/projects/1708738346/the-searzall

Dave is also more entertaining than you.

Re: A Liquid Nitrogen Cocktail Party

#58
post #24

Interesting fact about liquid nitrogen (that I learned from Dave Arnold's book, which is fantastic): liquid nitrogen is ~700x denser than gaseous nitrogen. So, if you vaporize a moderate amount of liquid in a contained space (e.g. spilling a dewar in a car or elevator): even if you manage to avoid touching the nitrogen itself, the gas can crowd out the oxygen and you can asphyxiate yourself. Since it's odorless and c…

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Re: A Liquid Nitrogen Cocktail Party

#60

__ Safety Note __ If you store LN in a thermos with a cap that seals the thermos, you've made a time bomb, and thermos shrapnel does not improve the flavor of cocktails.

Also remember - any dewar itself, improperly handled, can be a bomb! One professor I worked for hammered this concept into us when we started work in his lab. Yet my PhD adviser did not. Sometime after I graduated, one of my fellow grad students blew up a dewar!! (Luckily no one got hurt). He obtained an old dewar from another lab, and went through the usual cool-down procedure - evacuate the Outer Vacuum Chamber, fi…

The dewar I bought from Amazon isn't pressurized. It is literally a big thermos. I assume it loses more LN to the atmosphere than a pressurized dewar; on the other hand, the explosion risk isn't big.
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