Fire extinguishers are important equipment for fire safety. They can be divided into several basic types according to the different fire extinguishing agents and applicable fire types. Understanding the characteristics and applicable scope of these types can help people choose and use them correctly in different scenarios and effectively deal with fires.
1. Dry powder fire extinguishing
Dry powder fire extinguishers are one of the most widely used fire extinguishers at present. The dry powder fire extinguishing agents they are filled with are mainly ABC and BC. ABC dry powder fire extinguishers can extinguish Class A (solid material fires, such as wood and paper), Class B (liquid or fusible solid fires, such as gasoline and diesel), and Class C (gas fires, such as natural gas and coal gas). They are highly applicable and are common in various places such as factories, shopping malls, and office buildings. BC dry powder fire extinguishers are mainly used to extinguish Class B and Class C fires, and are suitable for gas stations, gas pipelines and other places.
Dry powder fire extinguishers cover the surface of the burning object with dry powder to isolate oxygen to extinguish the fire. The fire extinguishing speed is fast, but a certain amount of powder will remain after the fire is extinguished, which may cause pollution to precision instruments.
2. Carbon dioxide fire extinguisher
The carbon dioxide fire extinguisher is filled with liquid carbon dioxide. When extinguishing a fire, the liquid carbon dioxide quickly vaporizes and absorbs a large amount of heat, reducing the temperature of the burning object to below the ignition point. At the same time, the carbon dioxide gas covers the surface of the burning object to isolate the air.
This type of fire extinguisher will not leave any residue after extinguishing the fire, and will not cause damage to precision instruments, electronic equipment, archival materials, etc., so it is widely used in laboratories, computer rooms, museums, libraries and other places. However, carbon dioxide fire extinguishers are suitable for extinguishing Class B and Class C fires and fires of live equipment, and care should be taken to prevent frostbite and suffocation when using them.
3. Water-based fire extinguishers
Water-based fire extinguishers include water fire extinguishers and foam fire extinguishers. Water fire extinguishers mainly rely on cooling and suffocation to extinguish fires. They are suitable for extinguishing Class A fires, but cannot be used to extinguish fires of live equipment, Class B fires, and Class C fires.
The foam fire extinguishing agent filled in the foam fire extinguisher can form a foam layer on the surface of the burning object to isolate oxygen. At the same time, the water in the foam plays a cooling role. It is suitable for extinguishing non-water-soluble liquid fires in Class A fires and Class B fires, such as gasoline, kerosene, etc. However, for water-soluble liquid fires (such as alcohol, methanol) and live equipment fires, foam fire extinguishers are not suitable. Water-based fire extinguishers have high fire extinguishing efficiency and are environmentally friendly and non-toxic.
4. Clean gas fire extinguishers
Clean gas fire extinguishers are filled with clean gas fire extinguishing agents such as halogenated alkanes. When extinguishing fires, they will not cause pollution to the protected objects. They are suitable for extinguishing various flammable liquid fires, combustible gas fires, and live equipment fires. They are especially suitable for use in places such as precision instruments, valuable equipment, and cultural relics archives.
This type of fire extinguisher has a fast fire extinguishing speed, leaves no residue after extinguishing the fire, and has little impact on the environment. It is an ideal choice for fire safety in some special places.
