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Posted: Fri Oct 31, 2008 6:08 pm
by Lentamentalisk
john bunsenburner* wrote:Oh, and I've managed to make liquid nitrogen at home. Plus, you can earn money with it by making liquid oxygen and then selling that. You could even use it in your hybrid.
*edited to make it readable.

Care to elaborate? Last time I checked, it takes a crap load of liquid nitrogen to get just a few drops of liquid oxygen, and how do you expect to store it?

Posted: Fri Oct 31, 2008 6:46 pm
by jimmy101
john bunsenburner wrote:a scuba tank should do it m8, the 300bar ones would hold i guess. and its well worth the cash, you know the friken power u get from that is incredible. oh and iv managed to make liquid nitrogen at hoem plus you can earn money with it by making liquid oxegen and then selling that(or using it in ur hybrid
What exactly is the point?

Yes, with a couple hundred dollars worth of storage equipment you could use liquid nitrogen. If your goal is to blow yourself up I suggest blackpowder, it would be much cheaper.

Besides, liquid N2 is usually stored and transported at fairly low pressure. I seem to recall that the safety valve on the typical N2 transport dewar is set at only 5 bar or so. The N2 is kept as a liquid by evaporative cooling, not by being under high pressure.

I doubt the local gas supplier would fill a scuba tank with liquified nitrogen. In the US that would almost certainly be grounds to have all their licenses revoked. It's also probably illegal to put anything but a breathable gas in a scuba tank.

Posted: Fri Oct 31, 2008 8:03 pm
by Hotwired
I have doubts that the talk of using cryogenic liquids was started by a knowledgeable user of such things.

Anyway, it was about dry ice.

It works and it's probably been a form of missile propulsion since dry ice became commercial.

The newer ways of using it such as making a dry ice bomb for propulsion in a cannon are dodgy and a lot less controlled than pumping up a rated chamber to 900psi and using a proper valve.

On the plus side you don't need to put in much effort when using dry ice.

Depends how you use it really.

Posted: Fri Oct 31, 2008 8:18 pm
by Velocity
If you are looking to pressure pneumatics, why not buy <a href="http://www.amazon.com/Twin-Tank-Electri ... </a>...air compressor for only $1.31 sounds good...I am sure there are no hidden fees, like $170.00 mandatory shipping :roll:

Posted: Fri Oct 31, 2008 9:23 pm
by FishBoy
Haha random comment- My friends physics teacher (i'm in honors, so different teacher) made dry-ice bombs in each of his classes today, we could hear them across campus :D