Flammability limits diluent effect

Flammability. The flammability limits of mixts ofN trifluoride with gaseous fuels and the effect of N as a diluent are given in graphic form in Ref 18. Fuels examined are H, butane, and hexafluoroethane. The authors also report that... 

The basic test apparatus consists of a chamber into which a known concentration of vapor (gas) in air is introduced. After thorough mixing, ignition is attempted with a spark or a hot wire. A series of different concentrations are tested to establish the upper and lower concentration limits for flammability. Although normally run with fuel-air mixtures at ambient conditions, other oxidizing atmospheres, diluent effects and temperature and pressure variations can be studied. 

Lower flammability limits of vapors may be predicted quickly, including the effects of initial temperature and inert diluents such as N2 and CO2. The limiting oxygen content necessary for flame propagation can... 

In considering the application of the gas theory, it is necessary to discuss the limits of flammability of the flammable gases -- that is, the concentrations beyond which the gas is either too diluted or too concentrated to burn, as well as the effect of a nonflammable diluent on these limits. The flammable limits of some of the gases produced burning the thermal decomposition of cellulose are shown in Table 1(6). 

Table I. Effect of Diluents on Flammable Limits of Some Gases...

Bercic, G., and J. Levee. 1987. Limits of flammability of methanol-air mixtures effect of diluent, temperature, and pressure. Chem. Biochem. Eng. Q. 1(2-3) 77-82 cited in Chem. Abstr. CA 108(7) 55457h. 

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