Electric steam cannon?

[daccel]

Just had an idea today about using an electric arc to vaporize water creating steam pressure that would propel the projectile. Not sure if this is possible, didn't see it discussed yet on here...any thoughts?

[iknowmy3tables]

uhm an arc of electricity in water would ether be short circuited, or if it was distilled it would slowly separate into hydrogen and oxygen and become highly explosive and dangerous

yes steam guns have been made, but a better heat source than an arc would be a electric heating coil, which would take a decent amount of time to heat up

I'd still prefer propane because its faster and usually hotter

[Necrosis]

This is extremely unpractical but it does work, yes.

On the other hand, you could use a fraction of the energy to convert the water into oxygen and hydrogen..




*edit* Mister Iknowmy3tables, in fact it won't short circuit since you'd need a capacitor as large as a soda bottle anyway, and as far as i know, capacitors don't short circuit.

Edit two!

What you'll want is a low voltage, fast discharging beefy capacitor. (low voltage will heat the water up more but not too low, or it will just not flow at all.)
And pretty much distilled water. (distilled water is actually an insulator according to my physics book)

[jackssmirkingrevenge]

Surely you meant Electric steam kettle?



Generating instantaneous steam is impractical, the best steam guns generate pressure in a boiler the release it with a valve in the manner of ordinary pneumatics.

[daccel]

Well I got the idea from seeing exploding wires with capacitors http://www.youtube.com/watch?v=KxeUV7CXrlI, and assumed water conducted electricity and might do something similar. Maybe wire in water? I guess it's probably one of those things where you can get better performance in a smaller package using existing methods. Still might be a fun experiment 8).

[iknowmy3tables]

pumping electricity through tap water maybe it will heat the water a little but it will short circuit your power supply,
its not the same the whole exploding wire thing works because air is not a conductor and when its forced through that resistance it generates heat
tap water is a conductor so it will heat your power supply up and fry most of the parts

its the same reason why this black powder http://www.ctmuzzleloaders.com/ctml_exp ... parks.html wont ignite no resistance no heat

but say iodized or distilled water isn't a conductor but it still won't work because most of the energy in the charge is going to separating the H2O in an electrolysis reaction

[jon_89]

what about using the heat from a resistor?

[Novacastrian]

what about using the heat from a resistor?

Because that would reduce efficiency to about .05%

[Fnord]

Just tear apart a cheap coffee machine... use the heating element.

[DYI]

Fire is usually the best way to heat steam guns of any kind. The more fire the better. It would be good to go for high pressure and low volume, since you can use a smaller heat source (i.e. blowtorch). I may try a 1000 psi steam gun some day, but something tells me that that day is still quite a long way away.

[daccel]

Nah, I don't want to replicate one of the steam guns that's been done, I thought there might be a way to make the water explode instantly, but if it sounds too good to be true..haha.

[DYI]

MIT found a way to do it. 3500 psi steam with simple materials, no boiler, and less than 2 minutes reload time. Don't give up on this, because it can be done somehow, you just need to find a way.

[Necrosis]

but say iodized or distilled water isn't a conductor but it still won't work because most of the energy in the charge is going to separating the H2O in an electrolysis reaction

Wich would create even more pressure, though.

[DYI]

Wich would create even more pressure, though.

Along with a stoichiometric mix of pure O2 and H2 which has a lower ignition energy than oxy-acetylene and is very prone to detonations.

[Fnord]

MIT found a way to do it. 3500 psi steam with simple materials, no boiler, and less than 2 minutes reload time. Don't give up on this, because it can be done somehow, you just need to find a way.

Oh wait... DUH. I feel stupid for not thinking of how they did it earlier.

Anyone ever seen distilled watter is a microwave? It doesn't boil if it is left completely still, but when you touch it, it explodes. That may be how it was done.