Liquid fuel aerosol techniques

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Mike Everman
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re: Turboprop PJ experiment update

Post by Mike Everman » Mon Dec 19, 2005 3:05 pm

Yeah, Jonny, that's what I want to do, make an atomizer that uses propane as the driving gas. Like an air-brush tip or other paint sprayer. Maybe a smallish propane cannister could be talked into delivering quite a lot of gasolene.
Mike Often wrong, never unsure.
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Stuart
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Re: re: Turboprop PJ experiment update

Post by Stuart » Mon Dec 19, 2005 4:08 pm

Mike Everman wrote:Yeah, Jonny, that's what I want to do, make an atomizer that uses propane as the driving gas. Like an air-brush tip or other paint sprayer. Maybe a smallish propane cannister could be talked into delivering quite a lot of gasolene.
Yes, I think that is really a practical way to go, especially if the long term goal was an ultralight. You get rid of a fuel pump, it's easier to start with propane (then enriching with gas), but you mostly are dealing with a gas engine.
I'm writing an automated airplane designer in java, useful later when you guys get ready to bolt a p-jet onto some wings

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Re: re: Turboprop PJ experiment update

Post by Jonny69 » Tue Dec 20, 2005 8:38 am

Mike Everman wrote:Yeah, Jonny, that's what I want to do, make an atomizer that uses propane as the driving gas. Like an air-brush tip or other paint sprayer. Maybe a smallish propane cannister could be talked into delivering quite a lot of gasolene.
Don't say stupid things like that to me Mike. I'm going to end up taking my spray gun apart now! Sounds like the perfect place to find a fuel metering head to me!

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re: Turboprop PJ experiment update

Post by Bruno Ogorelec » Tue Dec 20, 2005 10:39 am

Blowing propane to atomize gasoline.... Damn, why haven't I thought of that?

Mike Everman
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re: Turboprop PJ experiment update

Post by Mike Everman » Tue Dec 20, 2005 3:28 pm

Certainly aerosol delivery isn't a new idea. We've talked about it before, and I made a demonstrator. (I am not on my computer so can't pull that up at the moment). I wonder what the magic number is, gas to liquid?
Anyhow, I've mostly been thinking of propane pressurization of a liquid fuel tank, but I'm squeemish about it. This sounds a lot safer.
Mike Often wrong, never unsure.
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re: Turboprop PJ experiment update

Post by Jonny69 » Tue Dec 20, 2005 6:01 pm

I've got a few little toys to play with in the garage in the new year.

One of them is an air mover, it's a kind of venturi that goes inline with a tube and you put compressed air in the side. It causes mass air movement down the tube ie it draws a lot of air in the front and can carry solids like grain. I wondered what would happen if you used propane instead of compressed air and if it would work as a valveless intake. Second is to fill the spraygun with thinners and drive it with propane gas.

It's just down to whether I've got the balls to light the suckers!!!

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re: Turboprop PJ experiment update

Post by larry cottrill » Tue Dec 20, 2005 6:39 pm

I wish I had my dad's old engine cleaner. It was a hand-held nozzle about an inch ID that sprayed a heavy shower of fine degreaser solvent on an engine block or whatever. It was trigger activated and driven by compressed air. Naturally, I don't know what the trade name of it was, but man, that would have been a natural for the kind of forced intake you're talking about. It was basically an air-driven ejector with the fluid sucked in by venturi action, just like a simple carburetor.

L Cottrill

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Re: re: Turboprop PJ experiment update

Post by Bill Lubarsky » Fri Dec 23, 2005 2:15 am

Jonny69 wrote:I've got a few little toys to play with in the garage in the new year.

One of them is an air mover, it's a kind of venturi that goes inline with a tube and you put compressed air in the side. It causes mass air movement down the tube ie it draws a lot of air in the front and can carry solids like grain. I wondered what would happen if you used propane instead of compressed air and if it would work as a valveless intake. Second is to fill the spraygun with thinners and drive it with propane gas.

It's just down to whether I've got the balls to light the suckers!!!
If you use propane as the source gas for the air mover you will only be able to keep the flame front inside a very low flows. The velocity of the gas/air mix through the air mover is higher then the flame propagation velocity at "interesting" flow rates. I had to do things like add oxygen to the incoming air and extend the device with a dump combustor to keep all the combustion internal.

Bill Lubarsky

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re: Liquid fuel aerosol techniques

Post by Jonny69 » Mon Jan 02, 2006 5:23 pm

Hi chaps, I had a play with my spray gun earlier today. Basically I might think about lighting it if I have an assistant with a fire extinguisher closeby, but I was a bit worried about the large quantity of fuel it can shoot out. It will certainly work!

Shooting water through it running on air I can get it to blast out a fog about 10 feet long completely atomised in a cone about 3 feet across. It's quite awesome, but I wasn't prepared to do it with thinners and light it by myself lol. Certainly blowing propane through it to carry the thinners was out of the question! Not by myself...

Interesting was how wet you can run the mixture. Winding the flow screw right out it can really carry some fuel out!!! I would like to see if it will atomise cooking oil, but I'll have to get another cheap gun to do this in. My guess is yes - if it can atomise 2-pack paint which is as thick as emulsion it will do the job no problem. You can also get it to fan the spray out into a flat triangle with less velocity which might actually mix the fuel with the incoming air a bit more effectively.

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re: Liquid fuel aerosol techniques

Post by Mark » Mon Jan 02, 2006 6:03 pm

That made me think, I have this high pressure sprayer, a few thousand psi or something I hook up to my hose. It can shoot a spray so fast and so far I can fog the opposite side of my 100 foot yard almost or if you aim it straight up it is fulfilling too, just entertaining. I bet it would make a good flame thrower with methanol but probably the methanol would destroy the rubber seals or something internally. Still, it seems like something fun to try if you were crazy enough or doing a show on Myth Busters.
Mark
Last edited by Mark on Mon Jan 02, 2006 6:29 pm, edited 1 time in total.
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re: Liquid fuel aerosol techniques

Post by Mike Everman » Mon Jan 02, 2006 6:07 pm

Cool, Jon! I'm going to try something today, if I get the motor de jour running. Thanks for the extinguisher reminder. Hat, goggles and no synthetic clothing too, I'm thinkin'. I don't have a sprayer to play with, so I'll jin something up.
I'm with you, I'll bet you could get a motor running on vegitable oil this way!
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re: Liquid fuel aerosol techniques

Post by Jonny69 » Mon Jan 02, 2006 9:04 pm

Heheheh, my main worry was the burn time. Where I used to work in special effects we had a flame thrower which worked on liquid propane. Propane burns real fast so as soon as you shut it off it goes out. Thinners burns a bit longer and if it lands on anything it continues to burn until it's boiled off as such, like petrol would do. Didn't fancy that down my arm, I had enough of that at my last job interview when I set myself on fire by mistake!

I got that job by the way 8)

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