Page 1 of 1

Oxygen amounts...

Posted: Wed Feb 03, 2010 10:27 pm
by deathbyDWV
Alright, so I have a question about my oxygen for my new hybrid.

For this post I'm going to say that:

air is 20% oxygen and 80% nitrogen

atmosphereic pressure is 15 psi

that's just to make things simple...

So the chamber will be filled with air. 1 part oxygen and 4 parts nitrogen.
I want it to have 5 parts oxygen for a five times mix.
So if I fill the chamber with 11.25 psi oxygen(chamber pressure) that would add 4 parts of oxygen.

Now I would have 5 parts oxygen and 4 parts nitrogen. (if I did maths right)
Then I would add 5x mapp fuel.
My question is, with this mixture, including the nitrogen in the chamber still, would it fire correctly? Or would I have to purge it somehow and remove the extre nitrogen.

Thanks in advance...

Posted: Wed Feb 03, 2010 10:58 pm
by artillerycreations
Yes it would burn just fine. Instead of charging with 5x worth of air at whatever pressure you need you are eliminating the extra nitrogen. Since you are just getting rid of extra non reactive gasses it would burn but not with the same characteristics. Due to lack of a "buffer gas" so to speak your flame front will travel faster and therefore a faster pressure spike and more peak power because of less time for chamber walls to absorb heat which in our case is power.

I describe the chamber as a sponge (on a molecular scale of course). With all that nitrogen in there the flames have to travel around the nitrogen molecules being the gaps in the sponge. Without that nitrogen or in your case a limited amount, the flame front will have little resistance. I hope that helps.

Posted: Wed Feb 03, 2010 11:31 pm
by deathbyDWV
Yes that helps. Thanks. That is what I was thinking but I wasn't sure. Now I won't have just purge the tank. I like the sponge comparison is good too.

Posted: Thu Feb 04, 2010 7:09 am
by inonickname
You should also do a search on oxygen hazards.. Not something safe to work with.

Posted: Thu Feb 04, 2010 7:55 am
by deathbyDWV
Yes I've done lots searching and reading on oxygen hazards. The most pressure the oxygen will experience outside of the tank is under 15 psi. That shouldn't be enough for any auto ignition or anything. Thanks for your concern though.