Fire extinguishing substances: classification, application features

Operation of modern fire extinguishing systemsinvolves the use of a wide range of substances, through which the fight against fire is realized. Traditionally, the main substance of this kind is water. Indeed, this is the most popular filling of fire fighting installations, but far from all this method is effective. Therefore, other kinds of fire-extinguishing substances are introduced into the working arsenal of fire services, the properties of which are developed and servicing technical means. So there are all the new powder components, liquid formulations and aerosols, gas and other versions of substances that can successfully fight the flame.

Classification of extinguishing agents

The basic principle of the separation of extinguishing agentsbased on the nature of the impact on the fire. The most common way to do this is to cool the combustion zone. In the process of extinguishing, the supply of materials active from the standpoint of cease-fire is carried out. At the same time, fire department employees should, as far as possible, mix structural elements and disassemble burning materials, allowing more effective cooling of affected surfaces. The following principle is based on the dilution of the reacting elements. In this case, the extinguishing agents are volatile or decomposing non-combustible materials, the coating of which contributes to a cease-fire. Insulating materials are also common, which affect the activity in the combustion zone by creating special barriers, bridges, etc.

There is another classification of extinguishing agentsmaterials, which is based on the physical state of the substance. In particular, liquid, gaseous, loose, solid, as well as fabric fillers of fire systems are isolated. It should be noted that the affiliation of fillers to different groups in accordance with this classification does not bind to the separation system mentioned above. That is, the classification of fire-extinguishing substances according to the principle of influence on the fire zone can allow entry into one of the categories of two or more materials with different physicochemical properties.

Cooling agents

Theoretically, combustion can be stopped ifhigh speed to ensure the removal of thermal emission. This principle can be realized through the use of refrigerants, which through cooling control the process of heat removal, minimize the activity of the source of combustion. A classic representative of a group of cooling materials is water - a fire extinguishing agent that has high heat capacity, availability and chemical inertness.

As with all universal materials, thisthere are drawbacks. First of all, water differs increased electrical conductivity, which in itself imposes serious limitations on its use. The situation is aggravated when the liquid is mixed with other additives, increasing the ability to conduct current. But this is not all the disadvantages. Water also has poorly expressed ability to adhere to relatively burning materials, which is why, in fact, special additives are introduced into it. As a result, other fire-extinguishing substances are obtained, which are various mixtures and solutions, usually on a salt basis.

Insulating substances

The most common material of this group -foam. Isolation effects contribute to effective flame suppression with minimal losses and risk in terms of toxic safety. The structure of the foam forms a colloidal system of liquid bubbles that have a gas filling. Often such substances have a double effect - insulating and cooling. At the same time, not all foam extinguishing agents can be used in extinguishing fires. For example, a diluted soap solution at home will not have any effect, since in the fire the structure of the emulsion will instantly be destroyed. Therefore, special solutions are used that have a relatively strong bubble structure capable of withstanding thermal and mechanical effects. In order to strengthen the foamy substance, special stabilizers are added to the solution compositions. Also with the foaming agent, the use of air emulsions is also combined.

The category of insulating materials isand powders for extinguishing fires. Although such substances are universal and have a multifactorial overwhelming effect on fire, nevertheless the ability to isolate sources of fire comes first. For such purposes, for example, use a fire extinguishing powder based on alkali metals, carbonate, bicarbonate, ammonium salts and other compounds. Also, these substances are used purposefully in extinguishing electrical equipment.

Dilution substances

This is a vast group of substances, which are mainlyare designed for use in special fire extinguishing conditions. For the cease-fire, materials capable of either diluting flammable vapors with gases to a non-combustible concentration or minimizing the oxygen content in the air to a level where combustion ceases to be maintained are used in this way. Various approaches to the supply of materials can be used, for example, in a common fire zone, into the air, or purposefully into a combustion object.

According to the practice of application, the most popularThis type of agent is carbon dioxide, which provides the most effective cessation of combustion in a fire. Extinguishing agents in the form of nitrogen and water vapor are also helpful depending on the conditions of use. For example, water vapor is used mainly to extinguish a fire in enclosed spaces and inaccessible places. During the processing of the object, water vapor fills the entire room, diluting and displacing air masses from it. Thus, the active substance prevents burning without exerting a harmful effect on people in the room. In addition, the double effect of extinguishing the flame with steam is sometimes provided. Firstly, the cloud itself acts, replacing the air. Secondly, the droplets formed from the vapor evaporate and absorb heat from the source of the fire.

Chemically active substances

This is the category of substances that haveinhibitory effect on the combustion process. The principle of extinguishing is based on the chemical effect of the agent on the fire zone. When a fire extinguishing agent comes into contact with the target object, it interacts with the active centers of the oxidizing reaction, as a result of which noncombustible or inactive compounds remain, stopping the combustion reaction.

Halogenated can provide such an effect.hydrocarbons. These are fire extinguishing substances with inhibitory effects that inhibit the activity of the combustion process. But it is important to take into account that such materials are dangerous toxic effects. As for the effectiveness of extinguishing, then this is probably the best group of materials for fire fighting. But, again, undesirable chemical activity significantly limits the scope of such substances. If we talk about specific compounds, the inhibitory substances can be represented by freons and other halo-based compounds based on ethane and methane. Experts call such materials chladones, attributing special designations to them indicating the chemical composition. Permissible conditions for the use of substances are also determined in accordance with the marking.

Mobile and stationary fire extinguishing equipment

By itself, the effectiveness of substances thattheoretically can assist in the fight against fire, is minimal if there is no streamlined material supply system. For this purpose, mobile and stationary installations are used that carry out the introduction or spraying of the active substance. Mobile vehicles include fire trucks that are operated by security services. However, it is not only ordinary cars with personnel. It is possible to include in the same category trains, aircraft and ships carrying out the elimination of fire in appropriate conditions. Also common and stationary fire extinguishing installations, which are designed to release fire extinguishing agents. For example, such systems are most often used in confined spaces and work with diluting active materials.

Among the main tasks that performstationary installations, it is possible to note the elimination or, as the minimum goal, the localization of the fire. At the same time, there are many variants of structural versions of such complexes. In particular, there are modular and aggregate systems. Also, against the background of the widespread automation of security systems, they deviate from manual control and fire extinguishing installations, complementing modern electronics and the latest remote control systems.

The use of fire extinguishing substances in the fire monitors

Fire extinguishing materials,as a rule, they are designed at the construction stage of the facility in which they will be installed. The fact is that such systems are the most demanding of communications, so the initial calculation of their location and installation is especially important. Typically, such units are used at production facilities, where containers for fire extinguishing substances of a particular type are also placed. This can be, for example, tanks with water or cylinders with foam or gas filling. Some modifications, by the way, are not designed specifically for the complete elimination of the flame. Their main tasks are reduced to the protection of production equipment or communications - for example, by irrigation.

Installations of this type may vary bydevice method. Far from always, the fireworks constructions have a stationary position. This may be mobile fire rods with the addition of a software or remote control. Of course, stationary installations are also common, the supply of fire extinguishing substances in which are often carried out through general engineering networks and communications. Such connection allows not to waste time on the organization of the operating infrastructure and immediately begin the process of fire extinguishing.

Automation in fire extinguishing installations

Modern automatic fireproofThe units allow, regardless of human involvement, to control the factors indicating the danger of fire and to start the extinguishing process in a timely manner. Usually, when the programmed values ​​are exceeded, the supply of the active substance begins and the alarm goes off with it. At the same time, there are different approaches to the means of controlling such systems. For example, sprinkler models are fully automated, but there are other systems that provide manual control. Thus, a fire extinguishing agent in gas fire extinguishing installations can be produced both automatically and at the operator’s command through the control panel. But such a control system already depends on the type of installation itself - modular ones are oriented towards greater autonomy, while centralized ones allow the maximum range of management approaches.

It is important to note safety factors that are notcan always be taken into account when operating automatic systems. Equipping with such installations justifies itself only in those cases when the elimination of the sources of ignition with the primary tools is impossible. Also, at some production facilities, the staff serves security systems outside of the clock. It is obvious that in such situations one cannot do without an automatic means of fighting fire. Another thing is that in order to minimize risks, you should initially make the right choice of extinguishing agent, the automatic supply of which as a maximum will entail only planned and previously calculated damage.

Fire Extinguishing System Classification

For each type of fire extinguishing installationuses a specific type of active substance. For security purposes, the use of multiple materials in one complex is rarely practiced. The most common system is a fire extinguishing system. Especially common are drencher complexes, which are used to protect areas with a high risk of fire. The effectiveness of such devices due to the fact that they can provide simultaneous irrigation of the entire area of ​​the protected area. Drencher fire extinguishing systems include pumping equipment, control panels, pipelines, water tanks, warning devices, etc.

The second most popular substance thatused in drencher designs, is foam. Such systems are used to protect local areas in industrial premises, to prevent the ignition of transformers and electrical appliances. Sprinkler installations with foam extinguishing material are also widely used. By the way, such units have much in common with water installations with the exception of special approaches to dosing. These are the main fire extinguishing substances used in stationary and mobile means of combating the sources of fire, but there are also specialized gas systems, powder and aerosol. As a rule, fire protection equipment with such fillers is used in special conditions - for example, in places where increased requirements are imposed on the maintenance of electrical equipment.

Conclusion

With all the variety of substances used inmodern fire extinguishing systems, experts still can not name the universal and most effective way to fight fire. There is a fairly clear segmentation of materials into classes depending on their technical and operational qualities. At the same time, an important role is played by the effect of fire extinguishing substances on humans and objects that are in the zone of ignition. For example, fire extinguishing systems with chemical fillers could well be the only means of suppressing fire. As practice shows, the use requires a minimum amount of fire extinguishing material of this type to fight the fires of the middle classes.

But the problem lies in the consequences thatentails the use of chemically hazardous substances. For this reason, technologists are learning new ways of extinguishing, including structural fire extinguishing. An effectively working fire extinguishing agent can unleash its full potential only in the only case if the system of combating the centers of ignition was properly organized. And in this regard, it is worth noting the importance of the basic installations that serve the material for extinguishing, and the methods of control, automatic or manual.