Ignition system and place on a combustion cannon

[RJB INDUSTRIES]

Hi everyone!

where is the place, where the ignition will work on with maximum quality?

the picture show you one simple pvc structure that i am using to make experiments like discover where i may put the ignition...



RJB INDUSTRIES

[jsefcik]

First what kind of fittings are you using????

cpvc???

what kind of ignition are you using?

[mattyzip77]

On all of my combustions, I placed my ignitor near the bottom of the chamber. Never had a problem.

[MrCrowley]

I think it is still recommended by most members to place the igniter in the middle of the chamber. This will create two flame fronts upon ignition which speeds up combustion of the fuel.

[warhead052]

First what kind of fittings are you using????

cpvc???

what kind of ignition are you using?

Hey, read the names of the picture...


RJB, try in the center, but with a spark strip. That would be, in my opinion the best spot.

[jackssmirkingrevenge]

This will create two flame fronts upon ignition which speeds up combustion of the fuel.

See it in action w0000!

[RJB INDUSTRIES]

ok, i have placed de electric ignition in the center also... See you...

RJB INDUSTRIES

[wyz2285]

two ignition spark? one in the front one in the back

[RJB INDUSTRIES]

hello. Having a fan inside the chamber, mixing de gas with the air, would i have a good explosion what ever the position of the gun?

[Crna Legija]

a good explosion

I hope not

Fans help but more importantly you need to get the fuel ratios right

[RJB INDUSTRIES]

The concentration of fuel, gas, will be always in the right place to fire? In near the terminals of the ignition system...?
Because I want to turn on the ignition and have, at same time the explosion... My doubt is if you point the cannon to the sky, you will have the explosion? Because butane has twice the mass of the air and my bolts, ignitors, are in the center of the chamber, and the gas maybe will be deposit on the PVC cape... I mean not around the ignitors...and i am not sure if like this it will fire...
A fan resolve this problem?
(the fuel ratio is very nice)

RJB INDUSTRIES

[jimmy101]

Yes, the fan insures that the fuel + air is well mixed.

Propane is a bit heavier than air (44 vs 28 and 32) but given enough time it will fully diffuse through the chamber. After several minutes the mixture will be uniform. But most spudders aren't patient enough to wait that long after fueling. A fan will equilibrate the mixture in a couple seconds.

And, the fan will increase the burn rate of the fuel somewhat, so leave it running during firing.

And, the fan can help with airing out the chamber between shots.