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Chris This is a ridiculous post. There is no secret to gas mixing or blending. Please dont make out like its some sort of voodoo. If you have questions about gas blending the best source for information would be CGA located in Alexandria. VA. Call information for the number. If you not satisfied with them then call Air Products and speak with one the engineers. Alex >After months of work we have a simi opperational Gas Mixing program using a >thermodynamic equation that compensates for gas compressability and >tempature rise in the cylinder during filling. > >But, we are in need of some examples of "real world" fills to begin >verifying mathmatical accuracy, and tuning the equations to reflect reality >not just mathmatical predictions. > >If you are pumping Nitrox, Tri-Mix, Argox, Neox, or any other blend, PLEASE, >if you would be so kind, share with me the following information. > > >1. Cylinder (manufacture, model, size, etc..), exp. OMS-108-steel, >Luxfer-80-aluminum. >2. Internal empty volume in Litres or Cubic Inches (if you don't know, we >can look it up for you) >3. Configuration, single or doubles. >4. Starting temp of the cylinders before filling. (EMPTY cylinders only!, >please no tank topping yet) >5. Was the cylinder surounded by Air or Water, if Water at what Temp. >6. First gas you added. >7. Fill rate you used. (PSI or BAR /minute) or your best guess. >8. Pressure at end of each fill. >9. Temperature at end of each fill (IF possible, even subjective Warm, Hot, >Very Hot would be helpfull) >10. Time before adding next gas if any. >11. 2nd gas you added >12. fill rate (PSI or BAR /minute) >13. Pressure at end of fill etc.. >14. Final fill pressure while HOT, and then after cooling if possible as well. >15. final gas percent analysis > > >Right now the program is yeilding the following RAW unverified / untuned >results, which are almost certainly Wrong. > >Example #1 > >The results of a 12.6L (Genesis 100) tank pumped to appx 239.6 ATM (3500psi) >with the following percents. > >Oxygen 21% >Nitrogen 79% > >The following is the pumping order, Pressure and estimated temperature. > >Gas AIR >Moles 99.7 >Real pres 239.6atm >Temp 74.3c >Ideal pres 238.0atm > >Specificaly you should pump each gas to obtain a tank pressure of > >Gas AIR >Pres (atm) 239.6 >Pres (psi) 3521.4 >Est Temp 74.3c 165f > >On colling to 20'c, the final pressure will be >202.1 ATM 2971.5 PSI > >========================= >Example #2 >The results of a 12.6L (Genesis 100) tank pumped to appx 239.6 ATM (3500psi) >with the following percents > >Oxygen 36% >Nitrogen 64% > >The following is the pumping order, Pressure and estimated temperature. > >Gas O2 AIR >Moles 19.1 81.5 >Real pres 37.1atm 239.7 >Temp 27.6c 73.7c >Ideal pres 45.2atm 338.0atm > >Specificaly you should pump each gas to obtain a tank pressure of > >Gas O2 AIR >Pres (atm) 37.1 239.7 >Pres (psi) 544.7 3523.7 >Est Temp 27.6c 81.7f 73.7c 164.6f > >On colling to 20'c, the final pressure will be >202.6 ATM 2978.1 PSI > >========================= >Example #3 >The results of a 12.6L (Genesis 100) tank pumped to appx 239.6 ATM (3500psi) >with the following percents > >Oxygen 12% >Nitrogen 38% >Helium 50% > >The following is the pumping order, Pressure and estimated temperature. > >Gas O2 He AIR >Moles 1.9 48.8 46.9 >Real pres 3.6atm 106 240 >Temp 20.6c 37.6 68.2c >Ideal pres 4.5atm 123.5 238atm > >Specificaly you should pump each gas to obtain a tank pressure of > >Gas O2 He AIR >Pres (atm) 3.6 106 240 >Pres (psi) 53.5 1558 3538.7 >Est Temp 20.6c 69f 37.6c 99f 68.2c 154f > >On colling to 20'c, the final pressure will be >206.1 ATM 3030.1 PSI > > > > > > >Christopher M. Parrett, President, Abysmal Diving Inc. >Makers of ABYSS, Advanced Dive Planning Software. >6595 Odell Place, Suite G. Boulder CO, 80301 >Ph, 303-530-7248, Fx, 303-530-2808 >ftp://abysmal.com/users/abysmal http://www.emi.net/boynton/abyss/abyss.html > >-- >Send mail for the `techdiver' mailing list to `techdiver@terra.net'. >Send subscription/archive requests to `techdiver-request@terra.net'. >
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