This calculator determines the flammability of a given waste gas stream by calculating the mixture’s Lower Explosion Limit (LEL) and Limiting Oxygen Concentration (LOC).
The LEL of a mixture is the dilute limit of fuel that will sustain a flame. Fuel flammability is often reported as a percentage of LEL (%LEL). If a mixture is at or above 100 %LEL and has an oxygen concentration that is at or above the LOC, the mixture is flammable. Below 100 %LEL the gas is too lean to burn. Note that NFPA 86 states that mixtures above 25 %LEL require continuous vapor monitoring. Mixtures above 50 %LEL shall interlock the thermal oxidizer system such that the high LEL stream cannot be introduced to the hot combustion chamber.
The calculator also calculates the limiting oxygen concentration (LOC). The LOC is the minimum oxygen concentration in a fuel, air, and inert mixture that will propagate flame. LOC values are calculated using NFPA 69 B.8.1 Method 1.
To use the calculator, select the compounds and enter the vol% of each component in the waste gas mixture. Note the compound list included is not exhaustive, and that the calculated values are estimates evaluated at ambient conditions.
This calculator is not to be used for equipment design. Contact PCC for a detailed assessment of your waste gas stream.
