Air-foam fire extinguishers. The principle of operation of the device and rules of use

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

In order to fight fire as effectively as possible, you need to use the right fire extinguisher, which will quickly cope with its task and at the same time minimally harm the environment.

Fire extinguisher device

Foam fire extinguishers use foam from the air and a foaming agent as the extinguishing agent. The fire extinguisher consists of a welded cylinder made of steel 0.8 mm thick, to the upper bottom of which a neck is welded containing a siphon tube, a lever for starting, a stem with a valve, a spring, as well as a pressure indicator and a sealed safety pin. A hose with a foam socket at the end is attached to the upper neck fitting.

There is a charge in the foam fire extinguisher bottle. To push it out, an inert gas, mainly carbon dioxide, is used. Foam is formed using a foam generator - a cylindrical bell made of metal or plastic. The jet of air entering the device hits the grid installed inside the fire extinguisher, which results in foam thrown under pressure into the fire.

Morechemical foam fire extinguishers can be found in operation, but their production has been discontinued due to difficulty in use and insufficient work efficiency. Due to the presence of an acid-base environment, such fire extinguishers are highly susceptible to corrosion (often the outlet hole overgrows). A nail was screwed onto the wire to devices manufactured back in the days of the USSR in order to clean the hole from rust in case of fire. Models of the post-Soviet period were equipped with special studs for this purpose.

Chemical foam fire extinguishers are quite dangerous to use, because the outlet must be cleaned before the chemical reaction begins. If you are late, you can get hit by a high-pressure jet. There are cases when a fire extinguisher could even explode.

Operating instructions

The most popular model is ORP 10. Such a foam fire extinguisher is most often used in industries where there is no way to spoil the interior. Before use, you need to break the protective seal and pull out the safety pin. When using the device, you must press the handle, thereby bringing it into action. Carbon dioxide, when it enters the cylinder, will create excess pressure, push the charge through the siphon tube into the foaming agent. The charge, mixing with air, will create mechanical foam.

In order to prevent sediment from forming in the charge, once every 3 months the foam fire extinguisher must be shaken, if the design is mobile - swing. Mobile fire extinguishers are brought to the source of fire and installed vertically.

Applications

Air-foam fire extinguishers are used to extinguish class A fires (combustion of solids and materials) and B (fires of combustible liquids capable of igniting or melting solids and materials). Such devices cannot be used:

• in cases where the equipment is energized;
• for extinguishing fires that can burn without access to air (aluminum, magnesium and their alloys).

Foam fire extinguishers are allowed to be used at an air temperature of +5…+50 °С. They are only used in temperate climates. If the ambient temperature is low, the extinguishing solution may freeze. Because of this, in the cold season, the fire extinguisher must only be transported in a discharged state.

Safety measures

Foam fire extinguisher operation rules prohibit:

• hit the balloon;
• breaking the seal is not to extinguish a fire;
• use the device when the valve breaks.

You cannot recharge the device yourself, you must use the services of certified specialists.

The foam fire extinguisher is safe for humans and has a relatively low cost, which depends on the volume of the cylinder.