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New hybrid design

Posted: Wed Apr 09, 2008 12:48 pm
by pat123
My friend gave some air tanks from the fire department. Every few years they have to get new ones. their operating pressure is 2000 psi. my other friend thought of a new design for a hybrid that I wanted to see what you think of it.

The fuel and air is pre mixed in the chamber. there is a constant spark in the barrel close to the chamber. as the mix is coming out of the chamber it ignites. could this work?

I'll post some pics of the tanks in a minute.

Posted: Wed Apr 09, 2008 1:02 pm
by pat123
here are the pics

Posted: Wed Apr 09, 2008 1:14 pm
by rcman50166
The design has a lot of flaws. If you have a continuous spark the chamber wouldn't fill up with fuel before firing. You need a timed spark so that it would fire just as the tank filled with new fuel. Also this couldn't work as a hybrid. From what I can see there is no valving of any type in the design. This design would not be very efficient either. The gap needs to be in the chamber to gat a nice combustion. It seems what your going for is like a puslejet engine. But if there is a valve that you may have forgotten to put in the illustration then I guess it could work as long as the valve closes after each firing. If I got those tanks I would make myself a nice air system for a pneumatic... If you ask me though.

Posted: Wed Apr 09, 2008 1:24 pm
by pat123
yeah I was also thinking about getting those pumped to 2000psi then have a regulator down to 100psi so i could put it in a back pack and hook it up to an airsoft gun. I would get a lot of shots out of that.

Posted: Wed Apr 09, 2008 1:51 pm
by Jared Haehnel
Perhaps if you put a read valve separating the tank and barrel. It would have to work like a pulse jet engine. As RC mentioned.

The moment you try and introduce more gas into the chamber it would force the BB out...

Posted: Wed Apr 09, 2008 2:28 pm
by Grizzlybear
I dont get it ... if you have so good tank why do you want to make hybrid ??? maybe you could make a uber pneumatic !?!?!?

Posted: Wed Apr 09, 2008 2:29 pm
by Jared Haehnel
With a tank like that he could make an very nice hybird...much more powerful then a pneumatic 8)

Posted: Wed Apr 09, 2008 2:34 pm
by Grizzlybear
Jared Haehnel wrote:With a tank like that he could make an very nice hybird...much more powerful then a pneumatic 8)
yea , maybe you're right ! I think you have to find better construction for hybrid . . .

Posted: Wed Apr 09, 2008 2:39 pm
by biggsauce
Shoot, with premixed gas/air, a big stack of burst disks and ammo, you could make quite the hybrid! One tank to hold your fuel mix with a valve leading to a second tank as a combustion chamber, you could have yourself one hell of a setup.

But wait, say you did have a tank pressurized to 2000psi, the air/propane would come to liquid right? But as gas is allowed to escape, would both fuel and air evaporate at the correct ratio for cumbution at the given pressure? :?

What would happen?

edit: spelling

Posted: Wed Apr 09, 2008 2:55 pm
by Sticky_Tape
biggsauce wrote:Shoot, with premixed gas/air, a big stack of burst disks and ammo, you could make quite the hybrid! One tank to hold your fuel mix with a valve leading to a second tank as a combustion chamber, you could have yourself one hell of a setup.

But wait, say you did have a tank pressurized to 2000psi, the air/propane would come to liquid right? But as gas is allowed to escape, would both fuel and air evaporate at the correct ratio for cumbution at the given pressure? :?

What would happen?
What's that bbq?

Posted: Wed Apr 09, 2008 2:55 pm
by psycix
Just weld in a spark plug and an union.
Weld or make a barrel to the other side of the union.
Tap/weld a small hole with pipe for fuel injection.
Put burst disk in union, high mix in chamber and a projectile in the barrel.
Spark.
BOOM!!!!!!
Sound barrier broken.

Posted: Wed Apr 09, 2008 2:59 pm
by Sticky_Tape
psycix wrote:Just weld in a spark plug and an union.
Weld or make a barrel to the other side of the union.
Tap/weld a small hole with pipe for fuel injection.
Put burst disk in union, high mix in chamber and a projectile in the barrel.
Spark.
BOOM!!!!!!
Sound barrier broken.
sounds most plausible rubs cats head. is it even remotly legal?

Posted: Wed Apr 09, 2008 3:16 pm
by biggsauce
Spudchucker, you lost me. Bbq? :?: :?

Posted: Wed Apr 09, 2008 3:35 pm
by DYI
Stoichiometric air/propane won't liquify until 204x, which is over 3 000 psi. But yeah, don't store 2000 psi propane air in a tank that's only rated for 2000 psi... the tank would get blasted to bits if the mix got ignited somehow.

Posted: Wed Apr 09, 2008 3:42 pm
by pat123
so how high of a mix could I do with this thing about 15X? I heard somewhere that the peak pressure is roughly 100psi for 1x, 200psi for 2x and so on is this accurate?