gas calcs

[altoid3000]

one gas source in the center of a huge cylindrical steel storage tank. this gas is heavier than air. I want to do some quick calculations to find out how much gas will leak out of the structure and how much of it will stay. There are going to be effects of wind entering the tank through vents at the top if the cylinder. The tank itself is not air tight. Effects of temperature gradients in the grain, sun radiation are also there. Without doing any elaborate modeling, if I want to get some reasonable results, what will you suggest? Any references to look up? I know ASME type publications give a lot of emperical equations that can be applied to quickly solve industrial type problem. Let me know. Any "thinking out loud" type of comments will also help me. Thank you.

 

[sailoday28]

altoid3000 (Mechanical) Sep 22, 2004
one gas source in the center of a huge cylindrical steel storage tank ??CENTER?? DOES THE GAS INITIALLY FILL THE COMPLETE BOTTOM OF THE TANK? WHAT IS MEANING OF CENTER?

FOR STARTERS, NEGLECTING INFLOW OF "WIND" AIR, THERE PROBABLY WILL BE MIXING OF AIR THAT IS SITTING ON TOP OF THE HEAVIER THAN AIR GAS. ONE METHOD COULD BE DIFFUSION.

THE DIFFUSED MIXTURE WOULD THEN BE INPACTED BY THE VENTILLATION.

 

[Montemayor]

altoid3000:

Please describe your application in detail. Your first description doesn't give clear, nor enough basic data. Do you have a vertical or horizontal cylindrical tank? It makes a difference. How "huge" is huge to you? What is the identity of the "heavy" gas? Is it flammable, toxic, or explosive? What is meant by center of tank? Is this an old-fashioned gas-holder that was used for atmospheric gas surges? If not, what is the Maximum Allowable Working Pressure (MAWP) on this vessel?

If you can't tolerate a leak, then contain the gas in an adequately sized vessel and equip it with the customary vents and other safety devices.


Art Montemayor
Spring, TX

 

[hacksaw]

you don't want elaborate modeling, yet you want to include the "effects of wind" entering the tank through vents at the top if the cylinder, the "effects of temperature gradients", "sun radiation", etc. all without doing any elaborate modeling, yet desiring "reasonable results".

i have to agree with the previous responses: a clearer statement of the problem is needed.

 

[altoid3000]

I apologize for providing insufficient data.

The tank stores grain - One of those huge grain elevator tanks. 114 foot dia X 75' tall. The gas is CO2. the tank is cylindrical upto 48 feet and then a conical top. There are 4 vents at the top at 90 from each other (each 2 feet X 2 feet). The wind enters the tank headspace through these vents.