Types of fire extinguishers - description, use and characteristics
The fire extinguisher is a simple, but at the same time effective tool in the fight against fire. Special equipment that allows each person to extinguish the fire sources independently, without exposing themselves and close people to danger. That is why it is important to know the classes of fire extinguishers. There are several types and types of fire extinguishers and each of them has its own characteristics.
According to the rules of fire safety, in all industrial and social facilities, there should be such a device in the transport, and not one, if the room is large. But what is the equipment, what types of fire extinguishers are and how to choose the right? Here in these questions and try to figure it out.
Fire extinguisher: what kind of fixture?
This is a special device designed to extinguish any type of fire. Termination of the combustion process is due to the substance contained in the fire extinguisher. This device can be both portable and mobile.A portable fire extinguisher in most cases is used during small fires, when fire affects small areas. But for large-scale fires used powerful tools.
Almost all types of fire extinguishers are in the form of a cylinder - a cylinder whose capacity is up to 100 cubic meters. They are equipped with a starting device, a special nozzle, which directly forms a jet of extinguishing agent. It flies out of the cylinder under great pressure. It is created during the injection into the fire extinguisher or upon leaving it. In some models, there is a special device that contains gas that helps to create high pressure during start-up.
Fire Extinguisher Classification
All types of fire extinguishers work according to the same principle - a fire-fighting substance in a cylinder is produced under high pressure to extinguish a fire. There are several characteristics by which you can determine the type of device and how to use it.
Fire extinguishers are divided by the volume of the cylinder:
- Manual subcompactors, with a capacity of up to 5 liters. This type is mainly used in the car as a portable device.
- Hand industrial.They hold from 5 to 10 liters and are used to equip industrial premises.
- Mobile stationary more than 10 liters, are used for large fires.
According to the method of operation fire extinguishers are divided into:
- manual - this is a large part of portable types of fire extinguishers, they are stored in a vehicle or small rooms and for their activation requires human exposure;
- self-activated, activated automatically when heated to a certain temperature or when smoke is fixed in a room, used in offices, in production or in warehouses;
- combined, combine hand and self-working devices.
According to the design of the trigger:
- having a squib;
- with valve;
- pistol type shutter;
- with starting device from a source of constant pressure.
According to the mechanism of the substance:
- under the pressure of a substance to extinguish;
- under the pressure of gas injected into the housing;
- under pressure of gas from a cylinder in the housing;
- gas resulting from chemical interaction of substances.
By type of active substance in the balloon:
- air foam;
The table below will help you understand the types of extinguishers and their application.
Active ingredient carbon dioxide
Fire extinguisher marking
OP under number 8
Powder general or special purpose. The basis of the powder are mineral salts. Components are also added to prevent wetting and clumping of the powder.
The extinguishing agent is carbon dioxide. During spraying, it expands 4 hundred times, forming a gas. The temperature at this time drops to -70 degrees.
The fire extinguishing agent is a halogenated carbohydrate that forms refrigerant and ethyl bromide during spraying.
The extinguishing agent is formed during the chemical reaction of aqueous solutions.
Where do they apply?
Versatile, suitable for extinguishing any type of fire.
These types of fire extinguishersused in areas where water cannot be used.
Perfectly cope with the extinction of solids, electrical installations, under voltage.
Recommended for extinguishing fires of medium intensity.
Do not use to extinguish substances that burn without exposure to oxygen.
A, B, C
How fire extinguishers work: features characteristics
All types and types of fire extinguishers have their own principle of operation. Each has its own characteristics in the design and prohibitions on use in certain conditions. Before you equip your office, car, business with a fire extinguisher, you need to understand in detail their characteristics.
This type is mainly used to extinguish solid materials such as wood, cloth, paper and others. Water is used as an extinguishing agent or surfactants are added.
Fire extinguishers work according to the following principle: while pressing the lever of the handle, the metal rod with the valve goes down, the spring of the locking device is compressed. Under pressure, the water, passing through the siphon tube, rises up and out through the nozzle.
These models are considered the simplest and are present in almost every home.
Carbon Dioxide Models
This type of fire extinguisher is designed to extinguish substances, minerals, electrical installations under current, internal combustion engines and flammable liquids.
They cannot be used for churning flames from materials that burn even without exposure to oxygen.
All types of carbon dioxide fire extinguishers work on this principle: carbon dioxide is displaced under the influence of excess pressure. During the opening of the starting device, carbon dioxide through the siphon tube passes to the socket. Getting on the burning material, it stops the access of oxygen, and then goes into a solid state. When you exit the socket, the temperature of carbon dioxide drops sharply to -70 degrees. This factor is the main feature of this type of fire extinguisher.
The test period for these fire extinguishers is one year, recharge occurs every 5 years.
They are recommended for extinguishing solid materials, as well as voltage-free electrical installations.
All powder fire extinguishers work according to this principle: during the actuation of the locking device, a valve opens, which releases the acidic part of the extinguishing agent. At the time of turning the device, alkali and acid react, and during shaking the speed increases.As a result, the resulting foam through the nozzle gets to the fire.
In addition to foam models, there is also air foam, which work on a different principle. It is based on the displacement of the solution of the foam former at an overpressure of the working gas, which can be an air mixture, pure nitrogen or carbon dioxide. During operation of the device plug with a working gas is punctured. The converter is extruded with gas through a valve and a siphon tube. In the nozzle, it is mixed with air and foam is formed. When it gets on the fire, it cools it and protects it from oxygen.
These fire extinguishers are checked once a year, recharging also occurs once a year.
All types of powder fire extinguishers are recommended for extinguishing petroleum products, solvents, solids, devices under high voltage.
If this type of device has an integrated gas pressure source, then it works like this:
- triggers the locking mechanism;
- the cylinder cap is pierced;
- gas passes through the tube to the lower part of the body and creates pressure;
- powder is displaced through the tube;
- pressing the trigger of the barrel, it is possible to feed the powder in small portions;
- when in contact with flammable substances, it helps protect against oxygen.
If the working gas is already present in the housing, then during actuation, the powder under the influence of nitrogen passes through the siphon tube into the hose and nozzle. Serve the contents of the fire extinguisher type op portions. It helps to isolate the burning element from the air.
Before you use this type, you need to make sure that there are no twists and kinks on the hose.
After extinguishing, you need to testify that the fire has been eliminated, and the fire will not resume.
Testing is carried out once a year, and recharge every 5 years.
Generator "Purga" aerosol
Designed for manual and automatic fire extinguishing in offices and industrial premises up to 200 square meters. When it is triggered, a highly dispersed aerosol is released, which stops burning. There are three starting nodes: thermal, electric and manual.
Fire Extinguisher Technique
We have told about the types of fire extinguishers and their use in everyday life, but there are also basic rules for working.Everyone should know about them:
- Electrical installations extinguish with a powder fire extinguisher is allowed only if the charge will be supplied in portions.
- The device can not be brought closer than 1 meter to the fire.
- The jet is directed only from the windward side.
- It is not recommended to take up the socket of a carbon extinguisher in order to avoid frostbite.
- Foam when extinguishing petroleum products should cover the entire surface of the hearth.
- Oil can not be extinguished from the top down.
- A stream of charge is directed from the nearest edge to the far, moving gradually.
- Extinguish a fire in a niche from the top down.
- It is better to use several types of fire extinguishers when eliminating a fire. The table above will help you figure out which of them can be combined.
It's no secret that any type of fire extinguisher needs maintenance. And it is as follows:
- periodically no later than one year to check the device;
- visually inspect and inspect the seal;
- carry out repairs;
Choosing a type of fire extinguisher
It will be difficult to unambiguously answer the question which of the fire extinguishers is better.Each model has its pros and cons. But still there is an opinion of experts that it is better to take a powder device. There are several reasons for choosing it: universal, minimal weight and low cost.
But there is a problem with it - powder. It is not just dust covering extinguished materials, it also penetrates every crack. To clean the room after it is very difficult. In addition, all equipment that is close by, from its impact can fail.
But the carbonaceous model has a sparing effect, therefore it will be an excellent auxiliary protection when extinguishing a fire near equipment and other items that need to be protected. In addition, carbon dioxide cools.
Air-foam fire extinguisher suitable for rigging a garage or protecting a wooden cottage.
To have such a device at hand is simply necessary to quickly eliminate the source of ignition at the right moment.