Flammability limits in oxygen 2

[espoiva]

Hello

I am working with mixtures of flammable gases and oxygen. I have the lower and upper limits in air, but I need to know if there exists any way to estimate the flammability limits in oxygen from the air limits.
Also, I would need to know some data base or some bibliography about flammability limits in oxygen.

Tanks.

 

[Guidoo]

Perry has a table (26-13) with flammability limits in oxygen (based on US Bureau of Mines Bulletin 503).

In Perry it is also written that:

"LFLs are about the same in oxygen as in air, but UFLs increase markedly in oxygen compared to air. For organic substances, UFLs at 1 atm are about 48 percent higher in oxygen than in air."

The table shows that difference between UFL in oxygen and in air varies between 40.5 and 53.5 for 8 substances.

Examples:

Methane: LFL(air)= 5.3 vol%, LFL(O2)= 5.1 vol%
UFL(air) = 14 vol%, UFL(O2)= 61 vol%

Ethylene: LFL(air)= 3.1 vol%, LFL(O2)= 3.0 vol%
UFL(air) = 32 vol%, UFL(O2)= 80 vol%

 

[25362]

One thing that shouldn't be forgotten is that even when the overall gas mixture is considered actually safe and out of the flammability envelope, striations can result in gas zones being dangerously within the flammability limits.

 

[Flareman]

See thread798-33615 which has just been revived and has a useful discussion on flammability as well as some references.

You can get a good idea of the flammable limits in Oxygen by constructing a flammability diagram as a complete oxygen/flammable/inert(N2) triangle and use the 79% N2 21% O2 line as the air line reference which contains the familiar limits in air. See also my spreadsheet at

http://www.geocities.com/flareman_xs/Gases/Flammability_calc.html

which should illustrate this a little better.

You could get a copy of the old standbys from the Bureau of Mines - Publications 503 and 627.