Since ancient times, improvised means, for example, sand and water, have been widely used to fight fires. But fire extinguishers specially designed for this purpose work much more efficiently with fire. Of the many types of fire extinguishers, the most widely used today are carbon dioxide and powder. These devices differ from each other in the principles of operation.
Carbon dioxide fire extinguisher
A carbon dioxide type fire extinguisher is designed to extinguish fires of a wide variety of substances, the combustion of which is impossible without air access. Such devices are widely used in fire brigades, at industrial enterprises, they are equipped with vehicles, apartments, summer cottages and garages.
The basis of such a fire extinguisher is a steel cylinder, in which the active substance is under high pressure. The device is equipped with a shut-off and start valve through which excess pressure is released. For the convenience of work, the carbon dioxide fire extinguisher has a cone-shaped bell. The working substance of the fire extinguisher is carbon dioxide.
When the fire extinguisher is activated, carbon dioxide is ejected through the funnel under pressure, forming a cloud about two meters from the device. The bell is directed to the flame in the area of the fire, trying to ensure that the largest area of coverage of the object with carbon dioxide is provided.
When it hits a burning object, carbon dioxide blocks the oxygen pathway. The place of ignition is cooled down, which prevents further spread of fire and stops burning. A carbon dioxide fire extinguisher is especially effective in the first stage of a fire.
Powder fire extinguisher
A powder-type fire extinguishing device is usually used to influence burning flammable liquids, for example, oil products. A powder fire extinguisher is also suitable for extinguishing electrical installations, which are problematic to extinguish by other means.
The powder fire extinguisher includes a container for storing the active substance and a locking and starting device. The principle of operation of the fire extinguishing system is based on the creation of excess pressure inside the container, followed by the release of a fire extinguishing composition that covers the fire site and stops the burning of materials.
Several methods are used to create pressure. There are models that use pressure gauges to find out the pressure inside the device. This design allows you to control the serviceability of the fire extinguisher during its long-term storage. There are dry powder fire extinguishers with gas generators; pressure is created in them after pulling out the safety check.
A dry powder extinguisher is especially good at eliminating smoldering fires. These include paper, wood, coal, rubber, plastic and textiles. Therefore, fire extinguishers of this type are widely used in relevant industries.