Fire Extinguishers

Fire Extinguishers

Fires, although a source of warmth and protection for our ancestors, have become a problem in recent years. One can hardly go one day without hearing about a forest fire devouring trees and homes alike. Fire trucks fly by with wailing sirens, onto the scene of a raging kitchen grease fire. Firemen in gas masks shove through doors and put out a gas fire in a chemistry lab. There are many types of fires, and unfortunately, fires are a daily occurrence all over the world. However, though fires are common, there are many different ways to extinguish them. Small fires are most easily extinguished by a fire extinguisher, although one needs to make sure that one has the right extinguisher for the job. Larger-scale fires are now fought with new and innovative methods, such as artificial precipitation. The key point to remember about extinguishing fires is that it can only be done when one of the factors necessary to sustain a fire is eliminated.
Fire needs fuel, oxygen and heat in order to burn. Fire extinguishers remove one of these elements by applying an agent that either cools the burning fuel or removes the surrounding oxygen. Therefore, extinguishers are filled with water or a material that can smother the fire, such as carbon dioxide. Please refer to the labeled picture towards the end of this report in order to gain a more accurate understanding of how a fire extinguisher actually works. Towards the top of the fire extinguisher (inside the body), there is a smaller cylinder filled with compressed gas. There is also a release valve to ensure that none of the gas can escape. When one is ready to use the extinguisher, one has to pull the safety pin and squeeze the handle. As you squeeze the handle, it pushes down on a tube (or rod, depending on the extinguisher), which in turn presses down on a valve that opens the passage to the nozzle. The compressed gas is released from the cylinder and applies a downward pressure on the fire extinguishing material. Essentially,...