|
Inerting is the process of converting from flammable or reactive conditions into a safe non-flammable state by the addition of an inert fluid (usually nitrogen). Combustion can take place provided three components are present simultaneously and in the right amount. These components are:
- Fuel
- Oxygen
- Source of ignition - friction, heat, electrical discharge, or flame
The right amount for combustion means that the concentrations of fuel and oxygen must be within the region of flammable mixtures and the ignition energy must be sufficiently large enough to initiate combustion.
The most common way of characterizing the flammability of fuels and their tendency to explode is by using the flammability limits in air. The lower and upper limits denote the minimum and maximum fuel concentrations, respectively, at which the gas mixture will propagate a flame if ignited. The limits are dependent on several factors, including temperature, pressure, and humidity levels of the mixture.
From the lower limits and the properties of the specific compound the minimum oxygen concentration for flammability can be calculated. This point and the lower and upper limits denote a region where the combustible gas/air/inert gas mixture is flammable. The extension of this triangular region is most easily represented by a graphical method, known as the Flammability Triangle. |
.jpg)