gas ignite?

styropyro said:

Lighting a match in a bottle full of gas wouldn't do much because there isn't enough oxygen in the bottle. Switch the gas out with a good Fuel/Oxidizer mix and now we are on to something... :

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Actually that is a very good point... Possibly if you turn a bottle upside down and fill it with gas thenput a match about 2 inches under the bottle neck and stand it all up somehow, that will definatly work.


OoooOhhhh! Guy playing laser instrument on TV as I posted this.

styropyro said:

Lighting a match in a bottle full of gas wouldn't do much because there isn't enough oxygen in the bottle. Switch the gas out with a good Fuel/Oxidizer mix and now we are on to something... :

Click to expand...

Half fill the bottle and try it with a long match, it will work because there is enough oxygen for the initial explosion will tear open the bottle letting more air/oxygen at the fuel, therefore letting it combust succesfully !  

Gasoline doesn't burn - the fumes do

You can actually put out a match with gas with no fumes - but I won't go into detail how to do because we'd have another evolutionary adjustment in intelligent dna


Mule

You need a spark to light gas.
and you need 5% of the room filled with that gas to make an explosion

Umm.. A bottle filled 1/5 with gas, and a match inside at the top would most likely go BOOM alright.. , depending on the type of bottle of course.

The problem is getting yourself at a safe distance to avoid the resulting explosion, which may include splashing/igniting gasoline.........

sounds like a pretty bad idea... unless you know what youre doing. I suppose the way i can think of to easily suspend the match inside the bottle would be to tie a string around it, and then dangle it in with the string halfway out of the bottle, and then screw the cap on. If you can somehow light the match from far enough away, you should have a big fireball. Remember that fumes are what ignite really fast, so a bottle full of gasoline fumes would be more explosive in one short burst than an entire bottle filled with gasoline, which would just burn for a long time, after making a pretty small explosion.

It would make a great video.

nikokapo said:

You need a spark to light gas.
and you need 5% of the room filled with that gas to make an explosion

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Gasoline will ignite from compression, just like diesel - no spark. Some people have accidently put gasoline in their diesel engines, with differing results.


Mule

1/5 is 20% LOL

as for igniting the gas, the rigt concentration helps alot (learned that with a potato gun ), but I guess compression works too?

Abray said:

1/5 is 20% LOL

as for igniting the gas, the rigt concentration helps alot (learned that with a potato gun   ), but I guess compression works too?

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i made a potato gun a few years ago, its awesome, it still works!

what you need to use is a hydrogen/oxygen mixture or any Oxy/fuel mix and i'm talking pure o[sub]2[/sub].

[hijack] if you want a powerful potato gun, use compressed air. a 5-6 gallon tank and a 1.5 inch ball valve and you're set. at 80 psi, i blew a potato though 1/2 inch plywood. [end hijack]

[hijack] mine's a combustion cannon, cause it's more "exciting", although compressed air would make a more powerful cannon.[/hijack]

but if you really wanted something to explode, I would take the fuel/oxy mix and then put a dark piece of something inside the bottle. That way you could maybe heat up the object enough to ignite the mixture around it. or pressurize it?

The compression factor only works if the air is compressed QUICKLY. A diesel engine works by compressing the air inside the cylinder to over 400 psi, again very quickly, causing the air become very hot. At just the right moment, the diesel fuel is spray-injected in, at very high pressure. When the "spray" hits the superheated air, it ignites. Gasoline in a diesel engine ignites way too fast, causing preignition, and lots of smoke lol.

If you simply used a normal compressor to compress the air inside a gasoline-filled container, it would never heat up enough to ignite the gas..unless you could pressurize the container in a fraction of a second.. this is of course if you have a container capable of holding the pressure such as that inside a diesel engine cylinder.

OT EDIT:.. If you really want to have some fun(sarcasm intended), try adjusting an RPM governor on an older detroit deisel engine.. If you let the lever go at the wrong time without being secured(it's a three-hand job to adjust one), the engine will "run away" and rev up to over 13,000 RPM before disintegrating into a million bits.... It's quite a sight to see.. one of my more interesting memories from my Army days LOL.

Hmmmm, I wonder what would happen if you used a Co2 laser to light gas... : clear objects absorb IR... probley nothing because its gas, but oh well.

you can use a laser to ignite black powder, and most other powdered explosives found in fireworks ect, but your cant really blow things up unless you have like a 15W laser laying around. you would want a high powered laser so you could be at a safe distance.

(your better off just making a make shift fuse out of paper or something and sticking it in there)

...........or put a small cap full of gas under an upside down rubbermaid trash can or a metal one & let it sit for a bit then sneak ignition under there...................................................................ok, don't do that!

Okay... To answer this thread you're going to have to know the flashpoint of the specific gasoline-vapor-to-oxygen mixture you're working with, then you'll need to know what power of laser will be able to create that amount of heat, while factoring in how much that particular wavelength is absorbed by that specific fuel-air mixture.

It's totally calculable, though there's a whole lot of variables. My guess is you'd need a multi-megawatt pulsed UVC laser to excite the air into plasma before you could accomplish this.