Fire Extinguishers: How Do They Work?

Fire extinguishers are a common sight in most buildings, and they contribute enormously to public safety. By using complex science and chemical reactions, fire extinguishers can quickly and effectively put out many different kinds of fires. Here's an explanation of how fire extinguishers work.

The Science of Fire

Fires start when heat and oxygen react with a fuel, which can be anything from wood or building materials to a variety of flammable liquids and gases. Putting out a fire requires the removal of one or more of these three essential components; fire extinguishers generally attack either a fire's heat or oxygen, or both. Once heat or oxygen is removed from the equation, a fire will quickly begin to diminish until it is extinguished completely.

Water Extinguishers

All fire extinguishers are essentially large aerosol canisters that contain pressurized fire-fighting materials, but a few varieties of extinguishers exist for tackling different kinds of fires. Some extinguishers use water as their primary active ingredient, which fights fires by rapidly cooling the flames. Water extinguishers are mostly useful for fires that burn using dry fuel, where no flammable liquids are present.

Dry Chemical Extinguishers

Instead of water, dry chemical extinguishers contain pressurized nitrogen as a propellant and dry chemical powder or foam as a fire retardant. Whereas water-based extinguishers remove heat from fires to put them out, the powder or foam in a dry chemical model smothers the flames by removing surrounding oxygen. These extinguishers are especially useful for fires with liquid or chemical fuels, as using water would only cause the fuel to spread and the flames to grow.

Carbon Dioxide Extinguishers

Carbon dioxide extinguishers combine liquid and gaseous carbon dioxide to combat flames. Carbon dioxide is a gas at room temperature and pressure, but it forms a liquid when put under pressure inside a canister. Upon activating a fire extinguisher, the liquid carbon dioxide rapidly expands into gas as it's released. Carbon dioxide fights fires by both forcing oxygen from the area and, as it transforms from liquid to gas, rapidly cooling the flames.

Fire extinguishers are an important component of public safety and are required for complying with safety codes and laws. Apartment Fire Extinguisher Service, Inc. provides a wide range of fire protection products and services to Jacksonville-area businesses. Contact us today at (904) 398-2030 to learn how we can help you improve your business's fire safety practices.