From my experience it’s never been a good idea to put any of those compressed air bottles near an open flame, so how would that work for fire extinguishers. Does the extinguish over power the compressed gases, or is it an entirely different kind of mechanism, and if so, how does that work?
In: Chemistry
Heating a sealed container causes the pressure inside to rise, and thus usually an explosion.
If the stuff in that container is flammable, then you get a *fiery* explosion.
Once out of the container, a non-flammable gas will not explode since its pressure can’t really rise. Fire extinguishers use non-flammable gas as propellant, and depending on the type they often use powder as the main extinguishing ingredient.
An ABC (the most common) fire extinguisher is filled with an non-flammable antioxidant powder that absorbs the O² that the fire needs while also blanketing it so I cannot spread. That powder is Aerosolized with pure CO² which as also 100% non flammable. When the Powder or Foam (made from said powder) fits a fire it blocks oxygen and fuel off so the fire cannot breath or spread.
It can be possible to make a fire worse by using the compressed gas from a fire extinguisher. For example if you have an oil fire and aim too low you might spread the oil around even more. This is one of the reasons why you should make sure to get the correct fire extinguisher for the type of fire you are fighting. Fire extinguishers are designed to prevent this from happening though. The pressure in them is not as high as it could have been. In addition they have a nozzle that is designed to slow down the material comming out and spread it around more. I have not heard of anyone having issues with their fire extinguisher which makes the fire worse. Even if it might spread the flames around a bit the extinguishing effects are much more powerful. The only problems I have heard of is when people try to use water to fight an oil fire instead of a proper fire exinguisher or a fire blanket.
About 90% of the aerosols use flammable hydrocarbons to pressurize aerosol cans like hairspray or brake cleaner. A fire extinguisher is clearly not pressurized with flammable hydrocarbons.
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