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Using pure 0xygen as a propellant, the perils thereof.
Posted: Mon Mar 10, 2008 6:37 am
by Shango
I read in a posting on this site that someone was looking at using pure oxygen as a propellant. Has anyone researched/discussed the dangers of messing about w/O2?
It has been my experience (Air Force) that working with 02 is very dangerous, except in very "Sterile" shop conditions (Absolutely oil free). One drop of oil and a burst of o2 and it could be bye-bye-birdie.
I don't mean to lecture, but just to point out a couple of things. Pure oxygen does not burn. However it aids in the combustion of any burning substance, oil being the most dangerous. IE: A test you can conduct at home (OUTSIDE), that was used to demonstrate the situation to us working on the flightline. (I never had the nerve to try it)
Have a lit cigarette in your mouth and blow through it. You see an increase in the glow and some flying ashes. Now, take a deep breath of pure O2 and then blow through the lit cigarette. Have friends standing by with an extinguisher. And, whatever you do, in the shock of what happens, gasp and inhale![/u][/i]
Re: Using pure 0xygen as a propellant, the perils thereof.
Posted: Mon Mar 10, 2008 8:05 am
by jrrdw
Shango wrote:I read in a posting on this site that someone was looking at using pure oxygen as a propellant. Has anyone researched/discussed the dangers of messing about w/O2?
It has been my experience (Air Force) that working with 02 is very dangerous, except in very "Sterile" shop conditions (Absolutely oil free). One drop of oil and a burst of o2 and it could be bye-bye-birdie.
I don't mean to lecture, but just to point out a couple of things. Pure oxygen does not burn. However it aids in the combustion of any burning substance, oil being the most dangerous. IE: A test you can conduct at home (OUTSIDE), that was used to demonstrate the situation to us working on the flightline. (I never had the nerve to try it)
Have a lit cigarette in your mouth and blow through it. You see an increase in the glow and some flying ashes. Now, take a deep breath of pure O2 and then blow through the lit cigarette. Have friends standing by with an extinguisher. And, whatever you do, in the shock of what happens, gasp and inhale![/u][/i]
What the hell are you talking about? Gasp and inhale??? Sounds dangerus to me??? Inhaling fire and ash. What exactly are you saying?
Posted: Mon Mar 10, 2008 8:22 am
by Jared Haehnel
He has a valid point... O2 is dangerous stuff not something for kids to be screwing around with. And even some adults....
But it can be used if the user is reasonably knowledgeable about the stuff and acts in a safe manner.
Posted: Mon Mar 10, 2008 9:41 am
by DYI
I always have some oxygen lying around, usually just a small disposable tank or two. Quite useful to help stuff along with burning. An interesting thing to do with it is to drill a hole through a piece of 2" dowel down the center, and hook up an oxygen hose to one side. Then light a match or similar in front of the hole, and start spraying oxygen through until the wood ignites. The result can shoot a flame quite a distance, and melt copper in a few seconds.
Filling homemade pressure vessels with high pressure oxygen isn't generally a very good idea, but the relatively low pressures that people are talking about when using it as an oxidiser in a combustion or hybrid can be worked with safely, so long as the vessel can take the increased combustion pressure and quicker pressure spikes.
Posted: Mon Mar 10, 2008 1:38 pm
by jimmy101
This is why if you buy (or rent) an oxygen cylinder none of your regulators will fit it. This keeps people from mounting, say, an oiled nitrogen regulator onto an O<sub>2</sub> tank.
I would hope that most people fiddling with this stuff would know of the extra hazards of pure O<sub>2</sub>. Steel wool burns in air, drop it into a container of pure O<sub>2</sub> and it'll burn about the same way that magnesium burns in air. That is, very fast and very hot.
Most things that you think of as being flammable in air (wood, paper, plastic etc.) become explosive in pure O<sub>2</sub>.
Posted: Mon Mar 10, 2008 2:16 pm
by CS
Well if you haven't heard of the hysteria surrounding pure O2... well your retarded.
(Hysteria - rightfully so)
Everytime someone mistakenly uses the term "oxygen" for "air" we will get about 5 people that pounce on the oxygen hysteria subject - and just how retarded the person is for using it.
I call only recall 1 or 2 situations in which pure O2 was used for a launcher. The one I recall specifically it seemed as if the operator used reasonable safety precautions.
One area I'd like to see pure O2 used is in a higher ROF combustion. The oxygen would circumvent the "venting" ordeal. Just dreaming...
Posted: Mon Mar 10, 2008 2:42 pm
by SpudFarm
sb15 used o2 in a gun out of sch40 steel and it held up nice... (i think)
he is experienced about hybrids in the first place so i would not mess around with o2...
Posted: Mon Mar 10, 2008 2:47 pm
by jimmy101
pimpmann22 wrote:I call only recall 1 or 2 situations in which pure O2 was used for a launcher. The one I recall specifically it seemed as if the operator used reasonable safety precautions.
Ya, the actual use of pure O<sub>2</sub> is pretty rare.
But ya gotta love people who use pure O<sub>2</sub> plus H<sub>2</sub> in a plastic gun.
Here is an example in a plastic "gun".
Posted: Mon Mar 10, 2008 3:18 pm
by BigGrib
I recall a post
More noob questions with the guy asking about using propane and o2 for fueling and I have said there that is is a bad idea for all sorts of reasons. But I digress, it seems that all the bases have been covered here. If you dont know what you are doing dont even think of working with o2
Posted: Mon Mar 10, 2008 3:25 pm
by daberno123
I remember someone from the Army who developed a simple inline sprinkler gun that was fueled off the soldier's portable O2 tank. Used to simulate RPG fire for training i think.
So it has been done, and done safely, but probably isn't the best choice to use
Posted: Mon Mar 10, 2008 3:43 pm
by BigGrib
No it was fuel by co2 not o2. big difference
Posted: Mon Mar 10, 2008 4:03 pm
by daberno123
Whoops! Nevermind that then, my memory faults me.
Posted: Mon Mar 10, 2008 6:34 pm
by D_Hall
If you want to go with an "oxygen enhanced" burn, Nitrous Oxide is the way to go. Thermodynamically, it's very similar to CO2 so pressure vessels and the like that can handle CO2 are good with Nitrous as well.
But what makes Nitrous an interesting (read: safe) oxidizer is the fact that at room temperature it's VERY stable. IE, it's not even an oxidizer at room temperature! To get it to release the oxygen you have to heat it up to... well, I forget what temperature, but it's well above room temperature. This means that even though you're dealing with an oxidizer you don't have to maintain clean room conditions.
Good stuff.
Posted: Mon Mar 10, 2008 6:49 pm
by DYI
I had an oxygen enriched combustion, and it was failsafe, but it failed eventually, and I wasn't willling to rebuild it, due to the use of rather questionable materials, and the inefficiency of the design.
SB15 made an oxy/MAPP hybrid that he ran at 4x or so, but apparently the costs of the oxygen made it rather impractical.
Burning steel wool in pure oxygen is an entertaining and easily available substitute for magnesium that I use fairly regularly if I need really high temperature for some reason. Simply light it with an electric current, then spray it with oxygen. Shaded lenses are, for obvious reasons, strongly recommended.
That's a good idea to use N<sub>2</sub>O. Shame it isn't quite as available as oxygen. How do it's oxidising properties compare to O<sub>2</sub>? I'd think it wouldn't be as powerful an oxidiser.
Posted: Mon Mar 10, 2008 8:27 pm
by Novacastrian
BigGrib wrote:No it was fuel by co2 not o2. big difference
Hey BigGrib, i remember the cannon in question and it certainly was fueled by oxygen. I remember JSR pointing out the fact and providing a picture of a air rifle that was used with oxy, it looked a little worse for it too.
I can't seem to find the link though, i'll have another look later.
Just thought i would clear that up
