Search results
Results from the WOW.Com Content Network
In an oxygen system the presence of oxygen is implied, and in a sufficiently high partial pressure of oxygen, most materials can be considered fuel. Potential ignition sources are present in almost all oxygen systems, but fire hazards can be mitigated by controlling the risk factors associated with the oxygen, fuel, or heat, which can limit the ...
For instance, to safely fill a new container or a pressure vessel with flammable gases, the atmosphere of normal air (containing 20.9 volume percent of oxygen) in the vessel would first be flushed (purged) with nitrogen or another non-flammable inert gas, thereby reducing the oxygen concentration inside the container. When the oxygen ...
Consider the first triangular diagram below, which shows all possible mixtures of methane, oxygen and nitrogen. Air is a mixture of about 21 volume percent oxygen, and 79 volume percent inerts (nitrogen). Any mixture of methane and air will therefore lie on the straight line between pure methane and pure air – this is shown as the blue air-line.
The system can be flushed with an inert gas to reduce the concentration of oxygen so that when the flammable gas is admitted, an ignitable mixture cannot form. In NFPA 56, [1] this is known as purge-into-service. In combustion engineering terms, the admission of inert gas dilutes the oxygen below the limiting oxygen concentration.
The original mass of flammable material and the mass of the oxygen consumed (typically from the surrounding air) equals the mass of the flame products (ash, water, carbon dioxide, and other gases). Lavoisier used the experimental fact that some metals gained mass when they burned to support his ideas (because those chemical reactions capture ...
Controlling gas and vapor concentrations outside the flammable limits is a major consideration in occupational safety and health. Methods used to control the concentration of a potentially explosive gas or vapor include use of sweep gas, an unreactive gas such as nitrogen or argon to dilute the explosive gas before coming in contact with air.
Oxygen gas is the second most common component of the Earth's atmosphere, taking up 20.8% of its volume and 23.1% of its mass (some 10 15 tonnes). [19] [70] [d] Earth is unusual among the planets of the Solar System in having such a high concentration of oxygen gas in its atmosphere: Mars (with 0.1% O 2 by volume) and Venus have much less. The O
In fire and explosion prevention engineering, inerting refers to the introduction of an inert (non-combustible) gas into a closed system (e.g. a container or a process vessel) to make a flammable atmosphere oxygen deficient and non-ignitable.