How Fire Extinguishers Work
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- čas přidán 28. 08. 2024
- Fire extinguishers are nearly ubiquitous, and they can be an invaluable, life-saving device. But what’s inside those little red cylinders, and how does it stop a fire?
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If you’re like me, then you constantly worry about buildings catching on fire when someone plays your newest mixtape.
And since you can’t compromise your artistic integrity because of a few exploding sound systems, you have to be prepared for the blazes that inevitably ensue once the beat drops.
A fire extinguisher is one of your best options - but what are these things, anyway? How do they work?
First, let’s talk about fire. Fire is the result of a chemical combustion reaction, typically between oxygen and some sort of fuel, like wood or gasoline. For the reaction to occur, the fuel has to reach its ignition temperature.
For wood, that’s about 500 degrees F (or 260 C). The heat decomposes some of the wood’s cellulose. The decomposed stuff is released as volatile gases, like a compound of hydrogen, carbon and oxygen. When the gas is hot enough, its molecules break apart. The atoms recombine with the oxygen to form water, carbon dioxide and other products. The heat keeps the fuel at the ignition temperature, so it keeps burning as long as there is fuel and oxygen.
There you have it. Fire, the result of extreme heat, oxygen and fuel. Fire extinguishers remove at least one of these elements from the equation.
Fire extinguishers are metal cylinders filled with water or a smothering material. When you depress a lever at the top here, the material is expelled by high pressure, kind of like an aerosol can. Imagine a fire extinguisher cut in half - see it?
OK, that plastic siphon tube leads from the bottom of the fire-suppressant reservoir to the top of the extinguisher. A spring-mounted valve blocks the passageway from the siphon to the nozzle. At the top of the cylinder, there is a smaller cylinder filled with a compressed gas -- liquid carbon dioxide, for example. A release valve keeps the compressed gas from escaping.
When you pull out the safety pin and depress the operating lever, it pushes on an actuating rod. The rod presses the spring-mounted valve down to open up the passage to the nozzle.
The bottom of the actuating rod has a sharp point, which pierces the gas cylinder release valve. The compressed gas escapes, applying downward pressure on the fire-suppressant material. This drives the material up the siphon and out the nozzle.
The proper way to use the extinguisher is to aim it directly at the fuel, not the flames, and spray in a sweeping motion.
There are three main types of extinguisher. A water extinguisher can put out things like burning wood, paper or cardboard - but it doesn’t work well on electrical fires or fires involving inflammable liquids.
In an electrical fire, water may conduct the current, which could electrocute you. Water will only spread an inflammable liquid, making the fire worse. Not a good look.
Then there’s the carbon dioxide extinguisher. The CO2 is kept in a pressurized liquid form. When the container is opened, the CO2 forms a gas. This gas is heavier than oxygen, so it displaces the oxygen surrounding the fuel.
This extinguisher is common in restaurants because it won't contaminate cooking equipment or food.
The most popular extinguisher material is the dry chemical extinguisher. These cylinders contain foam or powder, typically made of sodium bicarbonate (you know, baking soda), potassium bicarbonate or monoammonium phosphate.
Baking soda starts to decompose at only 158 degrees F (70 degrees C), and when it decomposes, it releases CO2. The CO2, along with the insulation of the foam, smothers fire.
But be careful. Most fire extinguishers contain a small amount of suppressant -- you can use it up in seconds. That’s why they’re only effective on relatively small fires. To put out a bigger fire, you need more equipment, like a fire engine, as well as trained professionals. But for the blazes that can pop up in your house, a fire extinguisher is a lifesaver.
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Lol didn't think everyone knew abut the mix-tape joke. That was great!!
Thanks a lot for this educational episode , I'm a new firefighter and I know how to use a fire extinguisher but unfortunately I don't know how it works and you made me aware of that . again thanks a lot , I hope if you can make an episode about smoke and how it can carry fire from the kitchen to the living room cuz most fire victims are killed by smoke in many many cases .
mehdi channel thanks for taking on a tough job to save lives
not actually correct the common agent is abc which is not baking soda type!
Nicely explained siR
Good one.
that was a great video on explaining it. i have to buy a new one. hardware stores have them n do fire department sale them too?
Dear sir, please explain on sensor attached fire extinguishers.
Most extinguishers don't have a smaller cylinder filled with anything. The extinguisher itself is pressurized...and that's also why there's a pressure gauge. Don't believe me? Then take an extinguisher and discharge it. Unscrew the top and see for yourself. If you want to only discharge the pressure and as little agent as possible, then turn extinguisher upside down when discharging until all pressure is gone.
2NaHCO3 -> Na2CO3 + CO2 + H2O
Sodium bicarbonate decomposition reaction when it heats up
Thank you, 6 years later. This helped me finish my chem project today :)
Now when my Mixtape drops,
I can stop a extremely catastrophic fire.
Bbc
*mix tape joke was fire*
Really informative. You taught better than my science teacher😄
Those zip-tyes securing the pin--should you remove them when you unpack the extinguisher?
Keep them on the extinguisher. Those “ZipTies” are called tamper seals. They are there to prevent any unwanted tampering with the pin as well as to ensure the pin doesn’t accidentally fall out of the extinguisher. They break very easily with a simple tug on the pull pin, so they won’t impede your ability to use in a fire situation.
Wet chemical extinguishers are found in restaurants. Foam is not dry chemical, it is, well, foam. There are two (common) types of dry chemical: Sodium Bicarbonate (of course) and the most common, ABC dry chemical is made of a mixture of Monoammonium Phosphate and Ammonium Sulfate. Please do some deeper research before making one of these types of videos.
This video killed me. Totally wrong on almost all points.
Can you do one on why we flinch
So water extinguishers are good for wood and paper, CO2 for electric fires and sodium bicarbonate is good for what?
I don't think it was too clear as to which extinguisher tackles what in the episode ^_^;
+Dash49 Sodium Bicarbonate (BC dry chemical) is usually found in mechanical rooms, areas with high class B hazards, and residential kitchens. There are a *lot* more types (and more popular) types then said in this not very well planed video.
+ironmatic 1 Thank you for the clarification :)
Class "A" is for things that turn to Ashes. (Paper, wood, etc.)
Class "B" is for things that go Boom! (Gasoline or other flammable liquids)
Class "C" is for Circuits. (Electrical Equipment)
Class "D" is for Dynamite (Heavy metals like Magnesium)
Class "K" is for the Kitchen (Grease fires)
So simple a first grader could remember! :)
@@robbynelson3 That’s a fantastic way to put it! I’m going to pass this on to my extinguisher technicians for when we train new guys.
it works now anywho DIS IS HELL A FUNNY
@ironmatic 1
Should those zip-ties securing the pin be removed when you unpack the extinguisher?
I learn fire safety in social studies.
Do an episode on How do headphones work?
It's literally a slightly less powerful miniaturised speaker in your ears connected along wires to an amplifier (think of the volume rocker on Apple EarBuds) and then along another wire to the input device. Some headphones have inbuilt speakers which then output sound to the device it's connected to.
I must say this was seriously poor educational video honestly.. There are 4 main classifications of fire .. A,b,c and I.. There is class A is paper, wood (normal combustibles) class B is flammable liquids (gasoline and oils) Class C is electrical and the only one that makes since is class K which stands for kitchen and is a newer type that was designed for fryers to help deal with "flashbacks" in vegetable oil.. It's a liquid which drastically lowers the temp of the grease because it can mix with the oil rather then another it.. There is also one other classification but very seldom would one encounter due to most people aren't even aware that metal can even ignite (being it takes super high temps) nevertheless it is class D. Now your example of an extinguisher wasn't far off from a cartridge operated one but (not entirely accurate but doesn't matter).. The biggest problem is you don't see a lot of cartridge operated ones and even the one you there to the side was not one.. Most or simply filled with the suppressant and pressurized to the correct psi with a non flammable gas (usually nitrogen).. Some extinguishers use a gas like co2 or fm200(which replaced halo due to EPA regulations) but all work off the concept the cylinder holds the pressure inside until you push down on the lever which pushes down on a valve stem allowing the suppressant to flow out the hose.. I am not trying to down your video I just thought I should clarify some..
Useful add-on!
3:00
I can't find how to order one! Can anybody help???
well thats how a cartridge extinguisher works most extingushers are store pressure!
😊
The issue is the fire extinguishers are too small and they run out very quick.
it wont work for me
not satisfied
+riya yadav What else are you looking for? Let us know and maybe we can help!
you should cover how headphones work
antbreach yt Thanks for the suggestion! I'm adding it to our list of potential topics... NOW
Antbreach I actually wanna see that
Nice try, undercover fire man.
Traditional Pressurized Metal Canister Fire Extinguishers are a 70 Year Old Technology that is a flawed design. You need to be intrducted to the UL Listed Rusoh Eliminator and love to get your thoughts? www.teamfti.com/eliminator
My science teacher is using this for the lesson Lmao
con·fla·gra·tion - not con-flag-er-ation
usually there is no problem with your videos. What happened? somethin wrong the teleprompter? Why are you looking down?
hi 8b people also nice video
Chobbawhubbs
Tubasauruses
Stop looking down :/
i didn't got my answer not happy
im way cooler than dev
Wouldn't the oxygen from co2 worsen the fire?
There’s no oxygen in CO2
1:21 3 words on the left, and a triangle on the right. ILLUMINATI CONFIRMED
Cringy af begininning