How Not to Do It: Liquid Nitrogen Tanks | Hacker News Reader

How Not to Do It: Liquid Nitrogen Tanks

pipeline.corante.com

46 pointsuptheirons14 comments

If you liked this blog entry, go check out http://pipeline.corante.com/archives/things_i_wont_work_with... which is a subselection of his blog entries about chemicals that he won't work with. For entertainingly good reason.

I love that particular subset of his blog. My favorite is still the entry on chlorine triflouride ( http://pipeline.corante.com/archives/2008/02/26/sand_wont_sa... ) This stuff is so nasty, it'll burn stuff that's already burnt. Oh, and there's no real way to put it out, so you just have to wait for it to finish eating through whatever was unfortunate enough to be in the vicinity when the spill happened.

"I do note that if you run the structure [O2F2 or FOOF] through SciFinder, it comes out with a most unexpected icon that indicates a commercial supplier. That would be the Hangzhou Sage Chemical Company.

"They offer it in 100g, 500g, and 1 kilo amounts, which is interesting, because I don't think a kilo of dioxygen difluoride has ever existed. Someone should call them on this - ask for the free shipping, and if they object, tell them Amazon offers it on this item. Serves 'em right. Morons."

"There’s a report from the early 1950s (in this PDF) of a one-ton spill of the stuff. It burned its way through a foot of concrete floor and chewed up another meter of sand and gravel beneath, completing a day that I'm sure no one involved ever forgot. That process, I should add, would necessarily have been accompanied by copious amounts of horribly toxic and corrosive by-products: it’s bad enough when your reagent ignites wet sand, but the clouds of hot hydrofluoric acid are your special door prize if you’re foolhardy enough to hang around and watch the fireworks."

From http://pipeline.corante.com/archives/2008/02/26/sand_wont_sa.... Brilliant.

That URL needs to lose a trailing hyphen:

http://pipeline.corante.com/archives/things_i_wont_work_with...

I can't edit it any more. :-(

I didn't mean to seem pedantic. :-) More just for those who get a blank page (the response I was receiving -- no visible indication of 404, at least with Flash, etc. blocked) and assume the site's timing out.

It is not pedantic. It is important and I am kicking myself for not having checked that the link was working.

Two stories about stuff like this:

A plumber in the town of Hilversum near Utrecht here once had an oxy-acetylene rig like this one http://static.werktuigen.nl/afbeeldingen/advertentie/8577/1/... in the back of his trailer, hit a pretty heavy bump in the road, the whole assembly fell out the back of the trailer.

Because of the force of the impact the reduction valve broke off from one of the cylinders and the whole thing went rocketing up and into the roof of a church a few hundred meters away.

A company that I free-lanced for had inherited an extravagant espresso machine from a bar that went out of business in Amsterdam. The thing was ancient and had been repaired many times, and not exactly by experts.

Over Christmas 1985 it remained plugged in and when we returned to the office on the 26th bits and pieces of the pressure tank were found embedded in the plaster walls.

We were very lucky, if someone had been operating the thing when it blew it would have been a 'closed casket' burial for sure.

Some time before, I attended a short course on handling the small/medium propane tanks. It's like with the nitrogen tank - it's relatively small, some people don't expect it to cause problems really -- but now I flinch every time I see someone kicking/rolling the bottle (way too common thing). In reality it could easily destroy a thick wall and cause a collapse, never mind tearing the people nearby into pieces. Unfortunately many people handling those bottles never learned much about them...

Dave Arnold at www.cookingissues.com posted about this recently. Their protocol for transferring the dewars includes letting the tank take the elevator alone. One particular time a student had set the dewar down a little hard, and the pressure had caused the tank to vent a minute later in the elevator, and blow a hole in the ceiling of the elevator. Had anyone ridden with it, they likely would have asphyxiated

edit: Link: http://www.cookingissues.com/2010/03/12/ka-boom-liquid-nitro...

When I was an undergraduate, a friend of mine worked for a physics prof who was researching something with superconductors. He cooled his experiments with liquid nitrogen. So we had a ready source.

We started by chilling our soft drinks with liquid nitrogen, then someone came up with the idea of sealing nitrogen into a 2-liter coke bottle. A coke bottle swells up to about double its original size before it pops, and it makes a most satisfying noise when it does. We'd use 1/2 liter of LN and wait about 10 minutes.

From there, we went to aerial explosions. Fill six trash bags with helium, tie them to a coke bottle of nitrogen, and let them float away. Ten minutes later, boom from somewhere high up and down wind.

I would like to take credit for all this, but in truth most of it was other guys' ideas. I was an enthusiastic implementor, though.

I feel a lot better about the big liquid nitrogen tank I had to sit next to while at a internship last summer. That thing was hissing all the time.

These stories are always turning up. If this isn't an excellent argument for requiring physics be taught in high school I don't know what is.

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