The use of carbon dioxide fire extinguishers: rules and safety measures

Among the variety of varieties of fire extinguishers, carbon dioxide is one of the most popular and affordable. Why and in what cases can it be used? Let's find out the answers to these questions by considering the design and use of carbon dioxide fire extinguishers, as well as the features of caring for them.

What is opamp

A carbon dioxide fire extinguisher is a device for extinguishing fires using liquefied carbon dioxide (CO ₂ ), it is also carbon dioxide.

Along with powder op amps are the most popular and affordable fire safety devices. This is due to several factors:

• cheaper price (compared to more versatile freon);
• the possibility of reusable use and reloading of a cylinder of CO ₂ ;
• do not leave traces of extinction and do not damage the surface (carbon dioxide disappears after use);
• have a long service life - ten years.

The device of carbon dioxide fire extinguishers

Such devices have the following design:

1. Lock-starting device.
2. A check that protects against accidental activation of the device.
3. Spray bell-blower, from where CO2 is supplied.
4. Siphon tube.
5. Cylinder body.

Inside the op-amp is carbon dioxide in a liquefied state.

Operating principle

During the use of carbon dioxide fire extinguishers, flame suppression is achieved through a combination of two factors:

• Lowering the temperature of the fire below the ignition point.
• Extrusions of O ₂ (necessary for the course of the combustion reaction) by non-combustible CO ₂ .

How is that?

Upon activation of RT, the carbon dioxide contained in the cylinder passes from a liquefied state to a gaseous one. Because of this, its volume increases to 500 percent. This is accompanied by a sharp drop in temperature (to minus seventy-two degrees) and selective crystallization (some kind of snow forms). Due to the formed very cold carbon dioxide in contact with a hot surface, it reduces its temperature. And also prevents the further combustion process, excluding oxygen.

Varieties

The main criterion by which carbon dioxide fire extinguishers are divided into types is the ability to transport:

• Portable op-amps have a maximum volume of seven liters (total weight - about twenty kilograms).
• Mobile - eighty liters. For their transportation, specialized carts are used. To activate such a device requires the efforts of two people at once.
  

Depending on the capacity, portable fire extinguishers are marked as follows:

• OU-1 - holds from 0.5 to 1 liter of liquefied ₂ ;
• OU-2 - up to 2 l;
• OU-3 - up to 3 l;
• OU-4 - up to 4 l;
• OU-5 - up to 5 l;
• OU-6 - up to 6 l;
• OU-7 - up to 7 liters.

Do not forget that volume and mass are not equal in proportion to one to one. Therefore, the weight of carbon dioxide in the cylinder will be less in numerical equivalent than its volume. For example, the OU-5 holds up to five liters of liquefied carbon dioxide. In kilograms this is about three and a half.

Please note that the charge volume of the fire extinguisher is only the amount of carbon dioxide that can be placed in it, and not the weight of the device itself. For example, a filled OS-1 weighs six and a half kilograms, and OS-5 weighs fourteen.

Mobile OTs from eight to eighty liters are marked similarly. The most used sizes are OU-10 and OU-55.

There is also a third variety - self-generated carbon dioxide fire extinguishers. They are used in rooms where there are no people (for whom they are no less dangerous than the fire itself). Triggered by activation of heat or smoke sensors.

Scope of carbon dioxide fire extinguishers

This type of OT is used to fight fires in the following categories:

• B - flammable liquids. Including fuel of various types, except alcohol (it does not need O ₂ for combustion).
• C - gaseous substances.
• E - electrical equipment. It is energized up to 1000 V, when it is removed up to 10 000 V.

The use of carbon dioxide fire extinguishers is convenient in that they do not damage the surface (like powder, foam or water varieties). Because of their structure, such op-amps quickly and efficiently eliminate the flame itself, without leaving their own traces. For this reason, they are successfully used:

• at the enterprises;
• in motor vehicles;
• in chemical laboratories;
• in archives and museums.

In what cases the use of op-amp is prohibited

Despite its effectiveness and versatility, this kind of OT can not always be used. There are a number of cases where the use of carbon dioxide fire extinguishers can do more harm than help. Below is a list of options in which the use of OT with CO ₂ is unacceptable:

• Wood, sawdust, raw cotton and other smoldering materials.
• Very high temperature of a burning object.
• Electrical voltage above 1000 V.
• Aluminum and alloys that contain it.
• K, Na and Mg in pure form.
• In case of fire of a person or animal, the use of carbon dioxide fire extinguishers is also prohibited. The fact is that due to the low temperature of carbon dioxide, frostbite occurs in the tissues of the body. It does not look so sad, as shown in the movie "Terminator-2" (especially since there was nitrogen, and not carbon dioxide). But not as harmless as in the movie "Tremors of the Earth-2: Repeat Blow." According to the plot, in order to deceive the thermal sensors of creatures, a person (in a miserable semblance of a special suit) was completely deprived of a stream from the OS. Subsequently, without any signs of frostbite (only slightly shaking from the cold) or dizziness (from excessive inhalation of CO ₂ ) he briskly ran to save the planet.

Security measures

Despite the danger to which a person using op-amps can be exposed, one should not panic and refuse to use this device. It is completely harmless if used correctly.

The following is a list of necessary safety measures when using carbon dioxide fire extinguishers:

1. Never direct a jet from an op amp at living things.
2. When using the appliance, avoid contact of the socket with exposed skin. Even if this element is not made of metal, but of a polymer composition. If possible, it is worth putting on tight canvas gloves (mittens) or wrap your hand in dense non-synthetic fabric.
3. In rooms with a reduced oxygen content, insulating respiratory protection should be used. After all, carbon dioxide released during device activation can lead to dizziness or loss of consciousness. In open space or in a well-ventilated building, there is no such danger.
4. Do not bring the bell of the fire extinguisher closer to the fire closer than one meter.
5. If possible, it is worth disconnecting the equipment. This is not a mandatory measure. After all, the OS is capable of performing its functions at voltages up to 1000 V.

Rules for using a carbon dioxide fire extinguisher

Having dealt with precautions, we consider the algorithm for using this device:

• Move a meter away from the fire. If the instructions on the label indicate a different distance, you must comply with this requirement.
• Point the bell toward the fire. Align it horizontally (bell, not an op-amp).
• Break the seal.
• Pull out the protective pin.
• Press the lever.
• As the fire is extinguished, direct the bell into the unlit fire.
• When the focus is extinguished, block the flow of carbon dioxide.
• Send the device for refueling or recharging to a service center.

OU health monitoring

Having dealt with the features of the use of carbon dioxide type fire extinguishers, we briefly consider the basic principles of care for such devices. Without proper control, the following complications are possible:

• arbitrary operation of the OS without activation by a person;
• failure of the device during a fire or its defective work;
• poisoning by carbon dioxide emitted in the room (if the mechanism breaks down);
• inability to get to the device (if it is not located correctly).

In order for all this not to happen, the legislation provides for a system of periodic checks on the condition and location of the fire extinguisher:

• Initial surface inspection of the device and its location.
• A quarterly check by the person in charge of the placement of the device and its body (dents, scratches, labels, tags and seals).
• Once every twelve months, in addition to a surface inspection, the fire extinguisher is weighed. If the weight loss is not more than five percent, it is returned to the place until the next verification. Otherwise, they will be taken to the service center for diagnostics and repairs.
• If the device is compelled to be stored in conditions with increased danger (direct sunlight, temperature changes, the possibility of accidental physical exposure), an analogue of the annual check is also carried out not every twelve months, but every six.
• Once every five years, a carbon dioxide fire extinguisher must be recharged.

Documentary base

In conclusion, we consider the basic regulatory standards that govern the rules for the use of OS in the Russian Federation:

• All information about the features of working with OS, the care of such devices and safety measures is contained in GOST R 51057-2001 and GOST R 51017-2009 (for carbon dioxide fire extinguishers with a volume of more than seven liters).
• Data on carbon dioxide (which acts as the main active substance) are given in GOST 8050-85.
• Information on precautionary measures is in GOST 12.2.037-78.