Fire is something that has been always very necessary for humanity due its multiple applications. But, when fire gets totally out of our control, destroying everything in its way it's necessary to contain it. That is why, all cities around the world have a fire department and firefighters prepared to extinguish and control fires.
George William Manby, marine and British inventor, born in Downham Market (Britain) in 1764, and died in Southtown (Britain) in 1854.
Manby was a British marine and mathematics teacher and a writer who published several books and also the designer of an apparatus for saving life from shipwrecks. When he was visiting Edinburgh at the beginning of the 19th century, when a violent and devastating fire started to raze, the fire was happening in a very high house. The firefighters arrived immediately but their hoses were too short to get up the place the fire was ocurring, and finally the fire razed through everything at its path. Witnessing this incident, Manby decided to make a hand held fire extinguisher.
Its functioning was simple, he put water and air under pressure inside a long copper vessel, closed by a spigot; when the spigot was opened, the compressed air pushed the water up to the place that was convenient.
Antique fire extinguishers
Before the modern fire extinguishers were invented, they used hoses to extinguish the fire, but the water needed was a lot, and the efforts were double, besides often the hoses weren't long enough or didn't have enough pressure to reach the difficult places. The first model of fire extinguisher was made from copper, and used just water and air,it was effective, but couldn't avoid the chemical reaction between oxygen, heat, and fuel, which are the elements that are necessary for a fire to start, so if the fire wasn't extinguished quickly, it raised again.
How do modern fire extinguishers work?
Currently, fire extinguishers use an extinguishing agent that can eliminate one of the three chemicals that cause the fire reaction. Some of the agents cool burning fuel while others displace oxygen molecules to destroy the chemical chain that causes the ignition. The remainder creates a barrier between the compounds, (although some of them just use water and pressure). A fire extinguisher works much like the cans of hair spray that women use to look stylish. When the handle is compressed, an inner canister of high pressure gas opens and it forces the extinguishing agent through a siphon tube and then comes out the nozzle.
Types of fire extinguishers: Is there a more effective one?
The short answer is: no, there is not a better one. Fire extinguisher are suitable or not, depending on the situation and there are several types of them.
Water and foam: This fire extinguisher uses water and a special foam, and works by separating heat from oxygen breaking apart the chain reaction. Water and foam extinguishers are very similar to the one that George Manby designed, and are used for organic material such as wood, paper and textiles. It's important to avoid using them when electricity is involved. We can find them at urban places like houses or buildings and places that are not likely to have dangerous reacting materials. To recognize them: the label is white.
Dry chemical: This fire extinguisher forms a barrier between fuel and oxygen, avoiding them to combine. Dry chemical extinguisher are normally rated for multipurpose use, since they can extinguish most kind of fires, although they are specialized at none. This extinguisher can be found at work places such as gas stations, or fabrics, but they can also be used at urban areas. The recognition label is blue.
Wet chemical: Like dry chemical extinguishers, those form a barrier between fuel and oxygen, but the difference is that the wet chemical avoids fire to reignite creating a layer beetwen oil and fire compunds. This type of extinguisher is very suitable to be used at cooking places, such as restaurants, food courts and cafes. The label used is yellow.
Carbon dioxide: Those ones, use cold pressure and carbon dioxide to take oxygen and heat away. Carbon dioxide extinguisher are specially used with flammable ignitions and electricity. Carbon dioxide is suitable at work places where electricity is used, and at car washers. The recognition label is black.
Water Mist extinguishers: The most modern fire extinguisher, although it's still under development, it works with all type of fires and doesn't content any chemical, working with only water and forming micro water droplets getting to be over 22 billion water droplets from only 1 liter of water!
How to use a fire extinguisher:
In this video, a firefighter from the Ashville fire department explain us how to use a fire extinguisher properly and professionally, and nothing better than relying on professionals!
