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| saladtossser |
 Posted: 06/12/2005 17:21 PM Post subject: |
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SpudZilla
Joined: 26 Mar 2005
Posts: 1237
98.19 Spud Bux
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| um jrblast... when a ice cream truck pass by, ask them for dry ice, and in a while it can burst a bottle (160+psi), so it is slow but strong. |
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| dryicerx |
| Posted: 06/18/2005 6:44 AM Post subject: |
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Private
Joined: 18 Jun 2005
Posts: 2
21.96 Spud Bux
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haha, this is a coincidence I was just checking out the forums about spud cannon's when I came across this, thats the dry ice cannon we constructed.
Before we did this we specifically got the PCV designed for -20C and the dry ice was not put in alone. If it was put alone the tempuratures would have been -78C or near and definly would have cause the PVC to brittle, instead the about cup of water plus a 1/4 cup of dry ice is only needed. The mixture of Dry ice and water (since its lowest temp is 0C) will start subliminating the dry ice into CO2 gas extremly fast. Since there is water, the tempurate is not going to go below 0 C. Theoretically a 3x3x3cm cube in that chamber completly subliminated would have brought the pressure to 200 PSI, but no one has time until it all sublimes, or use the same load over and over again.
Plus dry ice is extremly cheap, its ~75 cents a pound, so we usually buy 20 pound blocks or so a time (Kroger), and it lasts a whole day around 200 shots if we used it all, the rest is usually used for dry ice bombs and other stupid stuff. Just use a normal cooler, and it will stay for a couple of days before its completly gone. Usually humidity in the air condenses around the dry ice and forms a protective ice layer.
The chamber it self has two valves (electronic trigger valve, and a manual ball vale used for loading the dry ice as well as emergency release), plus there is a alternative place to pump air (forgot name, the same in tires), and a pressure guage so we can monitor the pressure. All PVC and glue are rated 150 PSI - 200 PSI.
Its quite effective since you can load lot of water plus a some dry ice then close both valves and it reaches around 100 PSI in about 5-10 seconds, release, then you can just shut both valves again and the pressure builds up again. The gas is not so cold since compressed air is heated (PV=nRT). |
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| jrblast |
| Posted: 06/18/2005 12:17 PM Post subject: |
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Private
Joined: 26 May 2005
Posts: 16
323.26 Spud Bux
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soo, dry ice is good but the actual compressor isnt worthit?
and saladtosser what if icecream trucks never pass by my house? ive got like 2 since all the snow melted... |
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| dryicerx |
| Posted: 06/18/2005 13:14 PM Post subject: |
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Private
Joined: 18 Jun 2005
Posts: 2
21.96 Spud Bux
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| Quote: | | soo, dry ice is good but the actual compressor isnt worthit? |
Compressor? No compressor is involved in this. I don't make my own dry ice, simply buying it from Kroger or other stores (really cheap). [/i] |
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| Tommy_TreeTop |
| Posted: 06/19/2005 14:06 PM Post subject: |
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Corporal
Joined: 13 Jun 2005
Posts: 67
5.70 Spud Bux
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Personally with experience with dry ice. It would work but it is very dangerous and i wouldnt use it as a propellant. Forgetting your technical terms and stuff, dry ice is like a time bomb waiting to happen. If something went wrong with your projectile the cannon could go boom and you would most likely die. But heck of course any cannon could kill you. But its just my opinion and you cna use it if you want to.
Peace out |
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| milty |
| Posted: 06/19/2005 18:26 PM Post subject: |
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Private
Joined: 03 May 2005
Posts: 22
0.13 Spud Bux
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| sweet- hoped i'd get to meet dryicex. does anyone know where i can get pvc pipe designed for cold temps? and how 'bout pressure release valves for 120 psi? btw our "super walmart" sells dry ice in the food dept. for about 99 cents. |
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| Caramanos2000 |
| Posted: 07/24/2005 2:02 AM Post subject: |
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Private
Joined: 20 Jul 2005
Posts: 8
27.78 Spud Bux
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| I make dry ice bombs with plane water and a large bottle of soda. Makes an M80 sound like nothing. Really awesome. Does take some time, but nothing more than to fill with a regular compressor. It isnt the cheapest thing but it can be found at stores like General Gases. I recomend not trying this, cause the force these dry ice bombs go off with is unbelivable. |
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