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| LucyInTheSky |
Posted: 01/07/2007 11:24 AM Post subject: Gas Things |
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 1st Lieutenant

Joined: 21 Apr 2006 Posts: 293 864.51 Spud Bux
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| Deko |
Posted: 01/07/2007 11:44 AM Post subject: |
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 Sergeant Major

Joined: 29 Sep 2006 Posts: 190 14.82 Spud Bux
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thats pretty sweet thanks for that site  |
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| Bluetooth |
Posted: 01/07/2007 12:03 PM Post subject: |
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 Brigadier General

Joined: 27 Jun 2006 Posts: 828 34.79 Spud Bux
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| Wow! Acetylene requires very little oxygen. |
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| squeaks |
Posted: 01/07/2007 12:06 PM Post subject: |
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Captain

Joined: 01 Oct 2006 Posts: 329 466.29 Spud Bux
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| Well, this is kinda usefull except that it tells us everything that we already knew-butane is weaker than propane which is weaker than mapp which is weaker than acetylene. It would be interesting to get some comparisons like this on different gases though. Nice find. |
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| Bluetooth |
Posted: 01/07/2007 12:12 PM Post subject: |
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 Brigadier General

Joined: 27 Jun 2006 Posts: 828 34.79 Spud Bux
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| It's still useful though. |
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| markfh11q |
Posted: 01/07/2007 12:25 PM Post subject: |
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 Magic Dust Man

Joined: 06 May 2006 Posts: 1585 61.83 Spud Bux
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I'd like to see the same chart with these included as well:
Propylene
Ethylene
Propadiene
Isopropyl alcohol, (properly vaporized)
and many others. |
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| benstern |
Posted: 01/07/2007 12:31 PM Post subject: |
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 Donating Member

Joined: 21 Sep 2005 Posts: 905 159.02 Spud Bux
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| How the hell did they find out the vapor pressure of acetylene to be 250 psi? |
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| SpudBlaster15 |
Posted: 01/07/2007 12:42 PM Post subject: |
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 Human blast shield

Joined: 18 Oct 2006 Posts: 1558 60.58 Spud Bux
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| squeaks wrote: | | Well, this is kinda usefull except that it tells us everything that we already knew-butane is weaker than propane which is weaker than mapp which is weaker than acetylene. It would be interesting to get some comparisons like this on different gases though. Nice find. |
Butane actual has a higher energy content per unit of volume than propane, it is just more difficult to meter and more expensive. |
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| beebs111 |
Posted: 01/07/2007 13:07 PM Post subject: |
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 Brigadier General

Joined: 25 Aug 2005 Posts: 812 847.12 Spud Bux
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| although the flame temp is hotter by 400 degrees, the burning velocity of propane is much higher, thus it burns faster blah blah blah |
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| SpudBlaster15 |
Posted: 01/07/2007 14:03 PM Post subject: |
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 Human blast shield

Joined: 18 Oct 2006 Posts: 1558 60.58 Spud Bux
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| The flame propogation rate in air differs by about 10%, and such a difference is irrelevant when it concerns our use. The difference between the fuels comes from the available energy content of each, which is influenced by the carbon to hydrogen ratio. In the case of butane, more carbon dioxide will form as opposed to water, and CO2 has a much lower heat of vaporization, meaning more energy can be released in the form of heat, leading to greater expansion. |
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| boilingleadbath |
Posted: 01/07/2007 15:37 PM Post subject: |
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 Moderator

Joined: 12 Mar 2005 Posts: 1647 5491.22 Spud Bux
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...I figured you guys would compare them.
Butane:
C4H10 + 6.5 O2 -> 4 CO2 + 5 H2O
(7.5 -> 9)
With a flame temperature of 3200*F, this gives us a flame pressure of 7.1 times the inital pressure.
Propane:
C3H8 + 5 O2 -> 3 CO2 + 4 H2O
(6 -> 7)
With flame temperature of 3450*F, this gives us a flame pressure of 7.3x.
That's a difference of less than 3 psi in a typical combustion cannon.
Practicaly the same, if you ask me. |
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