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| turbohacker |
 Posted: 07/02/2007 21:24 PM Post subject: |
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Major
Joined: 20 Dec 2006
Posts: 394
489.56 Spud Bux
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I think it is a wondurful idea!-However, if you plan on experamenting with other fuels like acetylene than be aware the some gasses become unstable at certian pressures. For example, the "unstable" pressure for acetylene is a mere 15psi when exposed t oxygen. You could fill a paper bag full of acetylene and proceed to pop it like a bag of air and it would (rather violently) explode in your face.-DO NOT ATTEMP THIS because it will cause permanent hearing loss! Im just warning you, I am not aware of the magical "unstable" level of other gasses, just read up before you experement.  |
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| noname |
| Posted: 07/02/2007 23:26 PM Post subject: |
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Mr Vortex
Joined: 10 Apr 2006
Posts: 2509
2698.56 Spud Bux
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| I personally haven't taken chemistry, but I know that this does work. I had a PVC chamber with a propane meter, a schrader valve, and a tire chuck. It also happens to have a bunch of BBs in the chamber! I pressurize the chamber to about a 7x or 8x mix, then hook it up to the ignition chamber via the tire chuck. I can then fire at any mix over 1x. |
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| Modderxtrordanare |
| Posted: 07/03/2007 0:05 AM Post subject: |
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Donating Member
Joined: 20 Nov 2006
Posts: 702
0.37 Spud Bux
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Isn't this just a combination of both a GenI tank and a GenII tank?
Gen 1.5? 
(P.S. I have alot to learn, for Spudblaster15 is my idol due to his chemistry "skillz" and I now know he hasn't even had a formal Chem class.  *studies*) |
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| SpudBlaster15 |
| Posted: 07/03/2007 0:13 AM Post subject: |
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Human blast shield
Joined: 18 Oct 2006
Posts: 1539
11.03 Spud Bux
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| turbohacker wrote: | | For example, the "unstable" pressure for acetylene is a mere 15psi when exposed t oxygen. |
Actually, acetylene does not have to be exposed to oxygen to become unstable at 15psi, as the pressure triggered reaction is not reduction/oxidation, but rather decomposition, where the acetylene decomposes explosively to hydrogen and carbon. The reason acetylene tanks can run at a higher pressure without being extremely dangerous is because the acetylene is dissolved in acetone within the tank, which stabilizes it. |
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| BC Pneumatics |
| Posted: 07/03/2007 0:16 AM Post subject: |
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Donating Moderator
Joined: 18 Jan 2005
Posts: 1156
2440.76 Spud Bux
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| Boo tripple bond! Hooray Beer! |
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| psycix |
| Posted: 07/03/2007 8:58 AM Post subject: |
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Major General
Joined: 25 Jun 2007
Posts: 1599
108.44 Spud Bux
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Just dont go acetelyne with a hybrid but just do propane.
Problem solved
The more power you want, the more danger you get....
To get back on starting post:
A premixed bulk tank is a good idea. Gasses will mix perfectly over time i believe but you can mix it faster with a fan.
Just do propane, it will give a nice blast too acetelyne is already dangerous when useing a 1x mix....
By the way, if such a huge premixed tank explodes, it will all be over for you.... |
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| _Fnord |
| Posted: 07/03/2007 10:14 AM Post subject: |
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reenigne
Joined: 13 Feb 2007
Posts: 1198
1699.58 Spud Bux
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| BC Pneumatics wrote: | | Boo tripple bond! Hooray Beer! |
If I had room I'd sig that
| psycix wrote: | | By the way, if such a huge premixed tank explodes, it will all be over for you.... |
Not only will it be all over for you, but you will be all over (the walls).
That's also something to think about, actually. In some cases pvc does have some undesirable static electric properties. Not really a big deal with most guns, but If you make a bulk tank you might want to consider putting a 2 or 3" burst disk on it as a precaution. The chamber would still rupture, but with any luck most of the energy would be sent through the disk, lessening the energy carried by the fragments. |
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| noname |
| Posted: 07/03/2007 10:20 AM Post subject: |
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Mr Vortex
Joined: 10 Apr 2006
Posts: 2509
2698.56 Spud Bux
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| Hasn't happened to me yet, but maybe I should install a union and burst disc as a pressure relief valve. |
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| PVC Arsenal 17 |
| Posted: 07/03/2007 10:27 AM Post subject: |
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WITTY PHRASE
Joined: 27 Mar 2006
Posts: 1232
748.69 Spud Bux
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I could always steel, but then I'd be asking for a spark!
Now again, I know nothing about mixtures and all that, but couldn't you scrap the propane meter entirely and (pulling numbers out my ass here) just fill the tank to... say 10 psi with propane, and then up to 50 psi with air?
That was probably a stupid question. How's this syringe thing work? |
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| _Fnord |
| Posted: 07/03/2007 10:44 AM Post subject: |
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reenigne
Joined: 13 Feb 2007
Posts: 1198
1699.58 Spud Bux
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You could just fill the tank up to the right pressure as far as I know. If you have a propane meter it would be easier though.
(In this case the numbers you gave would yield 16% propane/84% air. I'm too lazy to work out the right numbers)
For a small hybrid you can use a syringe to measure and inject the exact amount of propane you need. Some people use them on minis to meter butane. |
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| rednecktatertosser |
| Posted: 07/03/2007 10:46 AM Post subject: |
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Colonel
Joined: 22 May 2007
Posts: 601
451.78 Spud Bux
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I thin what you would do is put in one 'shot' of propane, then one atm of air(760 torr( thanks _fnord and Modder)), and repeat for the mix you want.
Last edited by rednecktatertosser on 07/03/2007 13:02 PM; edited 2 times in total |
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| _Fnord |
| Posted: 07/03/2007 11:02 AM Post subject: |
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reenigne
Joined: 13 Feb 2007
Posts: 1198
1699.58 Spud Bux
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716.23 bar is 10528 psi 
I think you meant 716 torr.
You need 4.2% propane by volume. Every 4.2% propane shot you add, you should add 14.7 psi (or 1 bar) of air.
(edit: keep in mind the tank already has 1 atmosphere in it, so you add one shot and then add 14.7 psi of air for each additional shot after the first)
Last edited by _Fnord on 07/03/2007 11:09 AM; edited 1 time in total |
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| rednecktatertosser |
| Posted: 07/03/2007 11:06 AM Post subject: |
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Colonel
Joined: 22 May 2007
Posts: 601
451.78 Spud Bux
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Yeah, i remembered that number from my chem class this past year and couldnt remember the unit to go with it. Thanks though
Also Bar=ATM right? |
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| Modderxtrordanare |
| Posted: 07/03/2007 12:24 PM Post subject: |
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Donating Member
Joined: 20 Nov 2006
Posts: 702
0.37 Spud Bux
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| Quote: | Yeah, i remembered that number from my chem class this past year and couldnt remember the unit to go with it. Thanks though
Also Bar=ATM right? |
1atm = 760torr
1 bar = ~760 torr
You didn't even remember the right number.
1 bar is a little bit less than 1 atm, but this is spudgunning, not rocket science. So pretty much, 1 bar = 1 atm. |
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| rednecktatertosser |
| Posted: 07/03/2007 13:01 PM Post subject: |
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Colonel
Joined: 22 May 2007
Posts: 601
451.78 Spud Bux
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Hey you know that i was thinking about spudguns and the like for that whole class. You actually kinda sorta paid attention and we mostly screwed around
Teacher-'this is a crucible'
Modder-'like Jesus?'
Redneck-'HAHAHAHAHAHAHAHA'
Modder-'HAHAHAHAHAHAHAHA'
Teacher-'whats so funny?'
Redneck-'Chemistry Jokes'
Modder-'HAHAHAHAHAHAHAHA'
Redneck-'HAHAHAHAHAHAHAHA'
That was funny |
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