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Dry ice

Posted: Thu Jul 26, 2007 10:57 pm
by Alabaster
Has anyone thought of a dry ice cannon?

Posted: Thu Jul 26, 2007 11:01 pm
by mopherman
yeah, but ice makes pvc very brittle and its just simpler to use co2

Posted: Thu Jul 26, 2007 11:04 pm
by singularity
its easier to use air or co2 but if you really want to get some metal pipe and rig up a burst disc setup on one end and cap the other end, the burst disc would connect up to the barrel

Posted: Thu Jul 26, 2007 11:04 pm
by Alabaster
in a metal chamber

Posted: Thu Jul 26, 2007 11:07 pm
by Alabaster
with some water ane dry ice i wonder how much the pressure would build with the certain amount of dry ice?

Posted: Fri Jul 27, 2007 12:19 am
by frankrede
Several hundred psi?

Posted: Fri Jul 27, 2007 1:00 am
by Modderxtrordanare
For every pound of dry ice you put in your chamber, it will expand into around 8 cubic feet of co2 gas. (8.3 to be exact)

Posted: Fri Jul 27, 2007 1:19 am
by frankrede
Is there a maximum pressure before the pressure would stop rising

Posted: Fri Jul 27, 2007 1:22 am
by chaos
frankrede wrote:Is there a maximum pressure before the pressure would stop rising
depends on the temperature, so its kinda like propane in a way which stops raising in pressure at a certain temperature i.e 100psi @20* C (not accurate)

i believe its around 800psi at 25*C (not accurate either)

Posted: Fri Jul 27, 2007 1:47 am
by frankrede
Hmm, I think I'll have to play with this dry ice stuff.

Posted: Fri Jul 27, 2007 8:26 am
by potatoflinger
Actually, just last night I was thinking about using dry ice with a strafer, just put water and dry ice in a metal pipe with an air hose and a pop-off valve on it, that way I could make my strafer portable and have a pretty reliable compressed gas source. The only problem is that after shooting for a few seconds, I would have to wait for the pressure to build up again.

Posted: Fri Jul 27, 2007 11:03 am
by Alabaster
i mean i was just wonderen if it was practical obveosly not with pvc. but i say its worth a try.

Posted: Fri Jul 27, 2007 11:09 am
by Modderxtrordanare
potatoflinger wrote:Actually, just last night I was thinking about using dry ice with a strafer, just put water and dry ice in a metal pipe with an air hose and a pop-off valve on it, that way I could make my strafer portable and have a pretty reliable compressed gas source. The only problem is that after shooting for a few seconds, I would have to wait for the pressure to build up again.
You could have a metal chamber and you fill it with dry ice and water, then when it builds sufficient pressure, it pops open the pop-off valve piloting a piston which leads to a bb barrel with a hopper or something.

/rambling

Posted: Fri Jul 27, 2007 12:51 pm
by DYI
If you used enough ice and water, the pressure should build to about 800 psi and stay there, because much of the dry ice would stay in its solid state due to the pressure not being able to rise any more. After you started using some of the gaseous CO2, more of the solid CO2 would sublimate to gas, replacing whatever gas was lost until the pressure came back up to 800psi. In a decent sized (and very strong) steel pipe, you could probably get even more CO2 than an equivalent sized cylinder filled with liquid CO2, and you wouldn't have to buy expensive tanks and regulators. Another plus is that you would have a strafer running on 800psi gas (unless you wanted to regulate pressure down). I think someone should try this. I probably will if I can get a hold of some dry ice, and 1000psi steel fittings.

Posted: Fri Jul 27, 2007 1:04 pm
by Alabaster
yea someone needs to and post there results cause like DYI said this can save us alot of money if it works.