Hope everyone's alright.

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Two injuries according to the scanner traffic, both walking wounded.

LOX contacted dry ice and caused a vessel fracture.

They're letting the engines go and keeping the ambulances.

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For those of us without Chemistry backgrounds, why did this explode AC? (or others)

Not sure. Probably just some trapped gas/high pressure issues, not an explosive reaction.

Big dry ice "bomb", basically. Pressure release, no chemical reaction.

No major injuries; looks like everything is going to be fine. Unless you're the professor that just lost a laser lab.

Wasn't it about 30 years ago that they had an explosion (gas cylinder?) in the Chemistry building that went through the floor?

Liquid oxygen is very cold, and in the right conditions will freeze CO2 (dry ice)...

temperatures like that if neglected will change the properties of the containter, and cause the metal to become brittle.

Something caused a pressure spike in the tank (valve closing quickly somewhere) and the tank couldn't hold it... So it ruptured, releasing liquid oxygen...

Fire loves oxygen, but also needs fuel. If there were open flames nearby along with something to burn, you're looking at a disaster.

Anyway, once the LOX hits the atmosphere it vaporizes, so you're looking at something similar to a BLEVE...except without the boiling part, and not quite as much expansion


or at least that's what the info that the OP postedd leads one to believe...

[This message has been edited by TexasRebel (edited 5/11/2010 11:48a).]

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Wasn't it about 30 years ago that they had an explosion (gas cylinder?) in the Chemistry building that went through the floor?

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That was in Jan '06. Had a nitrogen cyclinder with all the safety devices removed that blew through the ceiling of the lab and was stopped by a water pipe before exiting the roof of the building.

That was a much more devastating explosion. It destroyed an entire floor and put an entire wing out of commission for two months. Thankfully it occurred at night and no one was injured.

Whoops, it was only about 4 years ago

http://www.kwtx.com/home/headlines/2287091.html


And more

http://pipeline.corante.com/archives/2006/03/08/how_not_to_do_it_liquid_nitrogen_tanks.php

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A colleague of mine forwarded a copy of an accident report from Texas A&M. It seems that in mid-January they had a bit of a blowout there, thanks to a big liquid nitrogen tank. Now, liquid nitrogen cylinders are normally fairly benign, as long as you don't freeze your external organs off with the stuff or leave the liquid sitting around where it can condense oxygen out of the air. But idiocy will find a way - note the regular cylinder on the right and the new, improved model next to it.

These guys are usually equipped with pressure relief fittings, since nitrogen does tend to want to be a gas, and gases do tend to want to expand quite a bit. This tank, though, which seems to have been kicking around since 1980, had been retrofitted by a real buckaroo. Both the pressure relief and rupture disks had failed for some reason in the past, so they'd been removed and sealed off with metal plugs. You may commence shivering now.

Why it didn't blow long ago is a real stumper, but presumably people were taking nitrogen out of it quickly enough to keep things together. Not this time, though: at around 3 AM, things came to a head as the internal tank (these things are double-walled) expanded until it pressed against the outer one. That kept it from expanding anywhere else except on the ends, and as fate would have it, the bottom blew out first. The engineer's best guess is that this took place at around a 1200 psi load. It must have been quite a sight, although it's a damn good thing that no one was around to see it. I'll let the engineer's report take it from here:

The cylinder had been standing at one end of a ~20' x 40' laboratory on the second floor of the chemistry building. It was on a tile covered 4-6" thick concrete floor, directly over a reinforced concrete beam. The explosion blew all of the tile off of the floor for a 5' radius around the tank turning the tile into quarter sized pieces of shrapnel that embedded themselves in the walls and doors of the lab. The blast cracked the floor but due to the presence of the supporting beam, which shattered, the floor held. Since the floor held the force of the explosion was directed upward and propelled the cylinder, sans bottom, through the concrete ceiling of the lab into the mechanical room above. It struck two 3 inch water mains and drove them and the electrical wiring above them into the concrete roof of the building, cracking it. The cylinder came to rest on the third floor leaving a neat 20" diameter hole in its wake. The entrance door and wall of the lab were blown out into the hallway, all of the remaining walls of the lab were blown 4-8" off of their foundations. All of the windows, save one that was open, were blown out into the courtyard.

No one seems to have heard the celebrations, but someone noticed that the building's water pressure had gone a little wimpy and went to investigate, which I'll bet was a real eye-opener. I get the impression that they're still trying to track down the Mr. Fix-It who inadvertently rigged the tank for takeoff. The company engineer who came in to investigate noted that he's seen these kinds of "repair" jobs before, generally after they've powered through something.

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The rumor is that it was a post doc working in the group, but nobody really knows who did it.

Or at least that person isn't volunteering the information.

State Fire Marshall's alert to universities after the TAMU nitrogen flask explosion--with pictures!

http://www.tdi.state.tx.us/fire/documents/fmred022206.pdf

[This message has been edited by Aggiefan54 (edited 5/11/2010 11:45a).]

Via The Eagle:

TAMU police: 2 received minor injuries in the Chemical Annex explosion; unknown if students. Nitrogen dioxide or liquid nitrogen involved.

CS spokesman Jay Socol said the small explosion at TAMU's Chemistry Annex involved nitrous oxide. Unclear if finals will resume immediately.

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although it's a damn good thing that no one was around to see it

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My roommates brother worked night security in the chem building in '06... He heard it, but wasn't close enought to see anything.

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nitrous oxide

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Makes sense, that lab does a number of experiments investigating NOx. The two injured were grad students.

Recipe for a good Quad Bomb= 2 liter bottle, dry ice, and beer.

Don't get caught though

Sigh. My in-laws will start in on the jokes again. Like the campus is out of ice because the student who knew the recipe graduated.