Application of fire extinguishing agent in gas fire extinguishing installations. Gas fire extinguishing: device, principle of operation, types Gas fire extinguishing installations are used to eliminate fires

Site arrangement 17.06.2019

Site arrangement

In protected premises, a gas fire extinguishing method is used, the principle of which is to release a special non-combustible substance in a gaseous state. Pressurized gas (freon, nitrogen, argon, etc.) displaces oxygen, which supports combustion, from the room where the fire broke out.

Classification of fires eliminated by extinguishing the gas method

Automatic gas fire extinguishing is widely used in the localization of fires belonging to the following classes:

combustion of solid materials - class A;
combustion of liquids - class B;
burning of electrical wiring, live equipment - class E.

Volumetric fire protection is used in the protection of specialized banking equipment, museum valuables, archival documents, data exchange centers, server rooms, communication nodes, devices, gas pumping facilities, diesel, generator rooms, control rooms and other expensive property objects, both industrial and economic.

The premises where the control is located nuclear power plants, telecommunications equipment, drying and spray booths must be equipped with automatic gas fire protection in without fail.

Advantages of the method

Unlike other methods of extinguishing fires, automatic gas fire extinguishing covers the entire volume of the protected premises. The gas fire-extinguishing mixture within a short time of 10 - 60 seconds spreads throughout the premises, including objects of spontaneous combustion, stops the fire, leaving the protected values in their original form.

The main advantages of this method of fire extinguishing include the following factors:

safety of active materials;
high speed and efficiency of elimination of fires;
covering the entire volume of the protected premises;
high service life of gas-type equipment installations.

The fire-extinguishing gas mixture eliminates the flame with great efficiency due to the ability of the gas to quickly penetrate into hard-to-reach sealed and shielded areas of the protected facility, where access to conventional fire extinguishing equipment is difficult.

In the process of extinguishing a fire due to the operation of the AUGP, the resulting gas does not harm valuables in comparison with other extinguishing agents - water, foam, powder, aerosols. The consequences of extinguishing a fire are quickly removed by airing or using ventilation means.

Device and principle of operation of installations

Automatic gas fire extinguishing installations (AUGP) include two or more modules containing a gas fire extinguishing agent, piping and nozzles. Fire is detected and the unit is switched on by means of a special fire alarm, which is integral part equipment.

Gas fire modules consist of cylinders with gas and launching devices. Gas cylinders are subject to repeated refueling after their devastation during use. A complex automatic gas fire extinguishing system, consisting of several modules, is combined with the help of special devices - collectors.

In the course of daily operation, atmospheric control of the occurrence of smoke (smoke detectors) is carried out and elevated values temperature (heat detectors) in the premises. Constant monitoring of the integrity of the fire extinguishing system, cliffs in chains, short circuits are also made using fire alarm systems.

The gas fire extinguishing method occurs in automatic mode:

triggering of sensors;
release of fire extinguishing gases under high pressure;
displacement of oxygen from the atmosphere of the protected premises.

The emergence of a fire is a signal to the automatic launch of the installation of gas fire extinguishing in accordance with a special algorithm, which also provide for the evacuation of personnel from the danger zone.

The received signal about the occurrence of fire leads to the automatic shutdown of the ventilation system, the supply of non-combustible gas under high pressure through pipelines to the atomizers. Due to the high concentration of gas mixtures, the duration of the gas fire extinguishing process is no more than 60 seconds.

Varieties of automatic systems

The use of AGP is recommended in the halls where there is no constant presence of people, as well as where explosive and combustible substances are stored. Here, the detection of fires is impossible without signaling systems that automatically work.

Depending on mobility, automatic systems are divided into the following categories:

mobile installations;
portable AUGP;
stationary types of systems.

Mobile automatic gas fire extinguishing installation is located on special platforms, both self-propelled and towed. Installation of stationary equipment is carried out directly in the premises, control is carried out using consoles.

Portable type installations - fire extinguishers are the most common fire extinguishing means. Their presence is mandatory in every room.

The classification of AUGP is also carried out according to the methods of supply of fire extinguishing agents, according to volumetric methods (local - a fire extinguishing agent is supplied directly to the place of ignition, complete extinguishing - throughout the entire volume of the room).

Requirements for design, calculation and installation work

When installing automatic fire extinguishing systems using the gas method, it is necessary to comply with the norms established by the current legislation in full compliance with the requirements of customers of the designed facilities. Design, calculation and installation activities are carried out by professionals.

Creation project documentation begins with the examination of the premises, determine the number and areas of rooms, features finishing materials used in the design of ceilings, walls, floors. It is also necessary to take into account the purpose of the rooms, the characteristics of humidity, the ways of evacuation of people in the event of an urgent need to leave the building.

When determining the location of this fire fighting equipment Special attention it is necessary to give the amount of oxygen in areas of congestion of people at the time automatic start. The amount of oxygen in these places must comply with acceptable standards.
When mounting gas equipment, it is necessary to ensure its protection against mechanical influences.

Measures for the maintenance of fire fighting equipment

Automatic fire systems of a gas type need regular preventive maintenance.

Every month it is necessary to check the working condition and tightness of individual elements and the system as a whole.

It is necessary to diagnose the performance of smoke and fire sensors, as well as alarm means.

Each operation of fire extinguishing equipment must be accompanied by subsequent refueling of containers with gas mixtures and reconfiguration of the warning system. Dismantling of the entire system is not required due to the fact that preventive operations are carried out at its location.

Gas fire extinguishing- this is a type of fire extinguishing, in which gas fire extinguishing agents (GOTV) are used to extinguish fires and fires. An automatic gas fire extinguishing installation usually consists of cylinders or containers for storing a gas fire extinguishing agent, gas stored in these cylinders (tanks) in a compressed or liquefied state, control units, pipelines and nozzles that ensure the delivery and release of gas into the protected room, a receiving device - control and fire detectors.

Story

In the last quarter of the 19th century, carbon dioxide began to be used abroad as a fire extinguishing agent. This was preceded by the production of liquefied carbon dioxide (CO 2) by M. Faraday in 1823. At the beginning of the 20th century, carbon dioxide fire extinguishing installations began to be used in Germany, England and the USA, a significant number of them appeared in the 30s. After the Second World War, installations using isothermal storage tanks for storage from 2 began to be used abroad (the latter were called the fire extinguishing installation of low -pressure carbon dioxide).

Freons (halons) are more modern gas fire extinguishing agents (OTV). Abroad, at the beginning of the 20th century, halon 104, and then in the 30s, halon 1001 (methyl bromide) was used to a very limited extent for fire extinguishing, mainly in hand-held fire extinguishers. In the 1950s, research work was carried out in the United States, which made it possible to propose halon 1301 (trifluorobrommethane) for use in installations.

The first domestic installations of gas fire extinguishing (UGP) appeared in the mid-30s to protect ships and vessels. Carbon dioxide was used as the gaseous FA (GOTV). The first automatic UGP was used in 1939 to protect the turbine generator of a thermal power plant. In 1951-1955. Batteries of gas fire extinguishing with pneumatic launch (BAP) and electric power (BAE) have been developed. The option of block execution of batteries is applied using type SN type settings. Since 1970, the GZSM lock-starter has been used in batteries.

In recent decades, automatic gas fire extinguishing installations have been widely used, using

ozone-safe freons - freon 23, freon 227ea, freon 125.

At the same time, freon 23 and freon 227ea are used to protect the premises in which people are or may be.

Freon 125 is used as a fire-extinguishing agent to protect premises without constant human presence.

Carbon dioxide is widely used to protect archives and money vaults.

Extinguishing gases

Gases are used as fire extinguishing substances for stewing, the list of which is defined in the Code of the Rules SP 5.13130.2009 “Fire alarm and fire extinguishing installations” (paragraph 8.3.1).

These are the following gas fire extinguishing agents: freon 23, freon 227ea, freon 125, freon 218, freon 318C, nitrogen, argon, inergen, carbon dioxide, sulfur hexafluoride.

The use of gases that are not included in the specified list is allowed only according to additionally developed and agreed standards ( specifications) for a specific facility. (Code of Rules SP 5.13130.2009 "Automatic fire alarm and fire extinguishing installations" (note to table 8.1).

Gas fire extinguishing substances according to the principle of fire extinguishing are classified into two groups:

The first group of GOTV is inhibitors (chladones). They have an extinguishing mechanism based on chemical

inhibition (deceleration) of the combustion reaction. Once in the combustion zone, these substances rapidly decompose

with the formation of free radicals that react with the primary products of combustion.

In this case, the burning rate decreases to complete attenuation.

The fire extinguishing concentration of freons is several times lower than for compressed gases and ranges from 7 to 17 volume percent.

namely, freon 23, freon 125, freon 227ea are ozone non-destructive.

The ozone depletion potential (ODP) of freon 23, freon 125 and freon 227ea is 0.

Greenhouse gases.

The second group is gases that dilute the atmosphere. These include such compressed gases as argon, nitrogen, inergen.

To maintain combustion, a necessary condition is the presence of at least 12% oxygen. The principle of diluting the atmosphere is that when compressed gas (argon, nitrogen, inergen) is introduced into the room, the oxygen content is reduced to less than 12%, that is, conditions that do not support combustion are created.

Liquefied gas extinguishing agents

Liquefied gas freon 23 is used without propellant.

Freons 125, 227ea, 318C require pumping with a propellant gas to ensure transportation through piping to the protected room.

carbon dioxide

Carbon dioxide is a colorless gas with a density of 1.98 kg / m³, odorless and does not support combustion of most substances. The mechanism for stopping combustion with carbon dioxide lies in its ability to dilute the concentration of reactants to the limits at which combustion becomes impossible. Carbon dioxide can be released into the combustion zone in the form of a snow-like mass, while providing a cooling effect. From one kilogram of liquid carbon dioxide, 506 liters are formed. gas. The extinguishing effect is achieved if the concentration of carbon dioxide is at least 30% by volume. The specific gas consumption in this case will be 0.64 kg / (m³ s). Requires the use of weighing devices to control the leakage of fire extinguishing agent, usually a tensor weighing device.

Cannot be used to extinguish alkaline earth, alkali metals, some metal hydrides, developed fires of smoldering materials.

Freon 23

Freon 23 (trifluoromethane) is a colorless and odorless light gas. The modules are in the liquid phase. It has a high pressure of its own vapors (48 KgS/sq.cm), does not require pressurization with propellant gas. The gas leaves the cylinders under the influence of its own vapor pressure. The control of the mass of GFEA in the cylinder is carried out by the mass control device automatically and constantly, which ensures continuous control of the fire extinguishing system. The fire extinguishing station is capable of creating a standard fire extinguishing concentration in the standard time (up to 10 seconds) in rooms remote from the modules with GFFS at a distance of up to 110 meters horizontally and 32 - 37 meters vertically. The distance data is determined using hydraulic calculations. The properties of freon 23 gas make it possible to create fire extinguishing systems for objects with large quantity protected premises by creating a centralized gas fire extinguishing station. Ozone safe - ODP=0 (Ozone Depletion Potential). The maximum allowable concentration is 50%, the standard extinguishing concentration is 14.6%. Safety margin for people 35.6%. This allows Freon 23 to be used to protect premises with people.

Freon 125

Chemical name - pentafluoroethane, ozone-safe, symbolic designation - R - 125 HP.
- colorless gas liquefied under pressure; nonflammable and low toxic.
- Designed as a refrigerant and fire extinguishing agent.

Basic properties

01.	Relative molecular weight:	120,02 ;
02.	Boiling point at a pressure of 0.1 MPa, °C:	-48,5 ;
03.	Density at 20°С, kg/m³:	1127 ;
04.	Critical temperature, °С:	+67,7 ;
05.	Critical pressure, MPa:	3,39 ;
06.	Critical density, kg/m³:	3 529 ;
07.	Mass fraction of pentafluoroethane in the liquid phase, %, not less than:	99,5 ;
08.	Mass fraction of air, %, not more than:	0,02 ;
09.	Total mass fraction of organic impurities, %, not more than:	0,5 ;
10.	Acidity in terms of hydrofluoric acid in mass fractions,%, not more than:	0,0001 ;
11.	Mass fraction of water, %, not more than:	0,001 ;
12.	Mass fraction of non-volatile residue, %, not more than:	0,01 .

Freon 218

Freon 227ea

Freon 227ea is a colorless gas used as a component of mixed freons, gas dielectric, propellant and fire extinguisher

(foaming and cooling agent). Freon 227ea is ozone-safe, ozone depletion potential (ODP) - 0 There is an example of the use of this gas in an automatic gas fire extinguishing installation in a server room, in a gas fire extinguishing module MPKh65-120-33.

Non-flammable, non-explosive and low-toxic gas, with normal conditions is a stable substance. In contact with flames and surfaces with a temperature of 600 ° C and above, Freon 227ea decomposes to form highly toxic products. Frostbite may occur if liquid product comes in contact with skin.

It is poured into cylinders with a capacity of up to 50 dm 3 according to GOST 949, designed for a working pressure of at least 2.0 MPa, or into containers (barrels) with a capacity of not more than 1000 dm 3, designed for an excess working pressure of at least 2.0 MPa. At the same time, for every 1 dm 3 of the capacity of the container, no more than 1.1 kg of liquid freon should be filled. Transported by railway and road transport.

Stored in warehouses away from heating devices at a temperature not exceeding 50 ° C and in open areas, providing protection from direct sunlight.

Freon 318C

Freon 318c (R 318c, perfluorocyclobutane) Freon 318C - liquefied under pressure, non-flammable, non-explosive. Chemical formula - C 4 F 8 Chemical name: octafluorocyclobutane Physical state: colorless gas with slight odor Boiling point −6.0°C (minus) Melting point −41.4°C (minus) Autoignition point 632°C Molecular weight 200.031 Ozone Depletion Potential (ODP) ODP 0 Global Warming Potential GWP 9100 MPC w.w.mg/m3 w.w. 3000 ppm Hazard class 4 Fire hazard characteristics Slow-burning gas. On contact with a flame, it decomposes to form highly toxic products. There is no area of ignition in air. On contact with flames and hot surfaces, it decomposes to form highly toxic products. At high temperatures, it reacts with fluorine. Application Flame arrester, working substance in air conditioners, heat pumps, as a refrigerant, gas dielectric, propellant, dry etching agent in the manufacture of integrated circuits.

Compressed gas fire extinguishing compositions (nitrogen, argon, inergen)

Nitrogen

Nitrogen is used for phlegmatization of combustible vapors and gases, for purging and drying containers and apparatus from the remains of gaseous or liquid combustible substances. Cylinders with compressed nitrogen in the conditions of a developed fire are dangerous, since their explosion is possible due to a decrease in the strength of the walls at high temperature and an increase in gas pressure in the cylinder when heated. A measure to prevent an explosion is the release of gas into the atmosphere. If this is not possible, the balloon should be plentifully irrigated with water from a shelter.

Nitrogen should not be used to extinguish magnesium, aluminium, lithium, zirconium and other materials that form explosive nitrides. In these cases, argon is used as an inert diluent, and much less often, helium.

Argon

Inergen

Inergen is an environmentally friendly fire fighting system, the active element of which consists of gases already present in the atmosphere. Inergen is an inert, that is, non-liquefied, non-toxic and non-flammable gas. It is composed of 52% nitrogen, 40% argon, and 8% carbon dioxide. This means that it does not harm the environment and does not damage equipment and other items.

The method of extinguishing incorporated in Inergen is called "oxygen substitution" - the level of oxygen in the room drops and the fire goes out.

The Earth's atmosphere contains approximately 20.9% oxygen.
The oxygen replacement method is to lower the oxygen level to about 15%. At this level of oxygen, the fire is in most cases unable to burn and will go out within 30-45 seconds.
A distinctive feature of Inergen is the content of 8% carbon dioxide in its composition.

Other

Steam can also be used as a fire extinguishing agent, however, these systems are mainly used for extinguishing inside technological equipment and holds of ships.

Automatic gas fire extinguishing installations

Gas fire extinguishing systems are used in cases where the use of water can cause short circuit or other damage to equipment - in server rooms, data warehouses, libraries, museums, on aircraft.

Automatic gas fire extinguishing installations must provide:

In the protected premises, as well as in adjacent ones, which have an exit only through the protected premises, when the installation is triggered, the light devices (light signal in the form of inscriptions on the light panels "Gas - go away!" and "Gas - do not enter!") and sound warnings should be switched on in accordance with GOST 12.3.046 and GOST 12.4.009.

The gas fire extinguishing system is also included as component in explosion suppression systems, used to phlegmatize explosive mixtures.

Tests of automatic gas fire extinguishing installations

Tests should be carried out:

before commissioning the installations;
during operation at least once every 5 years

In addition, the mass of the GOS and the pressure of the propellant gas in each vessel of the installation should be carried out within the time limits established by the technical documentation for the vessels (cylinders, modules).

Testing of installations to check the response time, the duration of the supply of HOS and the fire-extinguishing concentration of HOS in the volume of the protected premises are not mandatory. The need for their experimental verification is determined by the customer or, in case of deviation from design standards that affect the parameters being checked, officials of the management bodies and divisions of the State Fire Service in the implementation of state fire supervision.

Mobile gas fire extinguishing equipment

fire fighting installation"Storm" jointly produced by the Nizhny Tagil OJSC "Uralkriomash", the Moscow experimental design bureau "Granat" and the Yekaterinburg production association "Uraltransmash" extinguishes a large fire at a gas well in just 3-5 seconds. This is the result of tests of the installation on fires in places of gas fields in the Orenburg and Tyumen regions. Such high efficiency is achieved due to the fact that Shturm extinguishes the flame not with foam, powder or water, but with liquefied nitrogen, which is thrown into the fire through nozzles installed in a semicircle on a long boom. Nitrogen has a double effect: it completely blocks the access of oxygen and cools the fire source, preventing it from flaring up. Fires at oil and gas facilities sometimes cannot be extinguished by conventional means for months. "Storm" is based on a self-propelled artillery mount, which easily overcomes the most difficult obstacles on the way to hard-to-reach sections of gas pipelines and oil wells.

Gas fire extinguishing based on fluoroketones

Fluoroketones - a new class chemical substances developed by 3M and introduced into international practice. Fluoroketones are synthetic organic substances in the molecule of which all hydrogen atoms are replaced by fluorine atoms firmly bound to the carbon skeleton. Such changes make the substance inert in terms of interaction with other molecules. Numerous test trials conducted by leading international organizations have shown that fluoroketones are not only excellent fire extinguishing agents (with an efficiency similar to freons), but also demonstrate a positive environmental and toxicological profile.

The gas fire extinguishing system is an extremely effective installation for the rapid elimination of a fire in initial stage ignition. Its special value is the absence of additional damage by the fire extinguishing agent to the protected equipment, stored documents, and artistic values.

The inevitable action of water, chemical foam, powders on building construction, interior decoration, furniture, office, household appliances, documentation in the course of extinguishing a fire often leads to direct and indirect material losses, quite comparable to those caused by fire, combustion products.

Filling the volume of the room with a mixture of inert gases that do not interact with burning materials quickly reduces the oxygen content (less than 12%), making the combustion process impossible. In gas fire extinguishing systems, the following are used:

liquefied gases - freons (carbon - fluoride compounds used as refrigerants), sulfur hexafluoride (SF6), carbon dioxide (CO2);
compressed gases - nitrogen, argon, argonite (50% nitrogen + 50% argon), inergen (52% nitrogen + 40% argon + 8% CO2).

The gases used, their mixtures up to certain concentrations (!) in the air are not hazardous to human health, and also do not destroy the ozone layer.

The automatic gas fire extinguishing system (AGS) is a combination of vessels for storing liquefied, compressed fire extinguishing agents, supply pipelines with nozzles, incentive (signal-starting) devices, and a control unit. There are several ways to enable ASGP:

auto;
remote;
local.

Two recent species are redundant, auxiliary methods that ensure the launch of the fire extinguishing system in case of malfunctions of the automatic fire alarm system. They are used by manually trained personnel of the enterprise, security personnel from the premises of the fire extinguishing station of the centralized gas fire extinguishing system or from the system starter installed in front of the entrance to the premises.

According to the type of object protection by an automatic gas fire extinguishing system, there are:

Volumetric fire extinguishing systems.

They are used for prompt filling with a gas mixture of a room or a group of rooms in a building where expensive technological, electrical equipment, material, artistic values are located.

Local fire extinguishing systems.

They are used to eliminate the source of fire on separate technological equipment, if it is impossible to extinguish the entire volume of the room.

The need to use an automatic fire extinguishing system, its type, type of fire extinguishing gas for various buildings, premises, equipment is determined by the current state regulations, rules in the field of fire protection.

ASSEMBLY AND INSTALLATION OF THE GAS FIRE EXTINGUISHING SYSTEM

To determine the need for designing an automatic fire extinguishing system, developing documentation, there are two main documents in this area of fire safety regulation: NPB 110-03, SP 5.13130.2009, which regulate all issues of design, installation of installations automatic fire extinguishing.

In addition, the following official documents are used for the calculation, design, installation, installation of a gas fire extinguishing system:

fire safety standards,

Federal standards (GOST R), defining the composition, installation methods, installations, methods and terms of testing, checking the performance of a fire extinguishing system with a gas mixture upon completion of installation and commissioning work.

There are also industry-specific, departmental norms for the installation of ASGP, which take into account the specifics of objects, the properties of the substances and materials used.

According to paragraph 3 of NPB 110-03, the type of automatic installation, the choice of fire extinguishing agent, type, method of fire extinguishing, type of equipment used is determined by the design organization based on the construction, design, technological parameters of the protected objects. As a rule, gas fire extinguishing systems are designed, installed, mounted standard solutions stations at the following categories of objects to be protected:

Buildings of federal, regional, special archives, where rare publications, various reports, documentation of particular value are stored.

Unattended technical workshops of radio centers, radio relay stations.

Unattended premises of hardware complexes of cellular base stations.

Car halls of automatic telephone exchanges with switching equipment, premises of electronic stations, nodes, centers, the number of numbers, channels is 10 thousand or more.

Premises for storage, issuance of rare publications, manuscripts, important accounting documentation in public and administrative buildings.

Repositories, storerooms of museums, exhibition complexes, art galleries of federal, regional significance.

Premises of computer complexes used in management technological processes, the stop of which will affect the safety of personnel, environmental pollution.

Server, archives of various media.

The last point also applies to modern data processing centers, data centers with expensive equipment.

The primary data for project development, calculations, further installation, automatic fire extinguishing installations are: a list of protected premises, the presence of suspended ceiling spaces, technical pits (raised floors), geometry, volume of premises, dimensions of enclosing structures, parameters of technological, electrical equipment.

Centralized ASGP call a system containing cylinders with GOS, installed inside the premises of the fire extinguishing station, and used to protect at least two premises.

Modular system includes modules with GOS installed directly in the room.

During the installation of ASGP, installation of individual elements of the system, commissioning, the following basic rules should be followed:

Equipment, components, devices must have technical passports, documentation certifying their quality (certificates), and comply with the project specification, conditions of use.

All equipment used for installation, installation of ASGP must serve at least 10 years (according to the technical passport).

The piping system must be symmetrical, evenly installed in the protected area.

Pipelines must be made from metal pipes. It is permissible to use a high pressure hose to connect the module to the pipeline.

Connection of pipelines must be carried out by welding or threaded connections.

The connection of the ASGP to the internal electrical networks of the building must be provided according to the 1st category of power supply in accordance with the "Electrical Installation Rules".

Premises protected by ASGP must have light panels at the exit "Gas - go away!" and at the entrance to the premises "Gas - do not enter", warning sound signals.

Prior to the installation, installation of equipment, pipelines, fire alarm detectors, you should make sure that the volumes, areas, availability, dimensions of construction, technological openings, the existing fire load in the protected premises correspond to the data of the approved project.

MAINTENANCE OF GAS FIRE EXTINGUISHING SYSTEMS

Perform routine maintenance work automatic systems fire extinguishers in working order, as well as to carry out installation, installation of ASGP, only specialized installation and commissioning organizations that provide services on the basis of a valid license of the Ministry of Emergency Situations of the Russian Federation for these types of activities are entitled.

Any amateur activity, including the involvement of employees of the engineering services of an enterprise, organization, is fraught with unpleasant, often serious consequences.

Automatic gas fire extinguishing equipment, especially those operating under pressure, is quite specific and requires qualified handling. The conclusion of a service contract will save the owner, the head of the enterprise from problems related to the proper maintenance of the ASGP, for the design, installation, installation of which a lot of money has been spent.

It is necessary to test the operability of the ASGP equipment immediately before the system is put into operation, and then once every five years. In addition, current routine maintenance is required (inspection, adjustment, painting, etc.), repair, replacement of equipment if necessary, as well as weighing cylinders, modules to establish the absence of leakage of GOS within the time limits established in the technical passports for vessels (containers ).

It should also be borne in mind that fire inspectors of the Ministry of Emergency Situations of the Russian Federation, when conducting scheduled, operational inspections of the fire regime in buildings, premises, must pay attention to the staffing, operability of the AGPS, the availability of technical documentation, a service agreement with a licensed organization. In case of gross violations, the head may be held liable under the law.

© 2010-2019. All rights reserved.
The materials presented on the site are for informational purposes only and cannot be used as guidance documents.

AT modern conditions widespread electrification, not every fire can be extinguished with ordinary water. Some materials do not tolerate contact with liquids, therefore, they cause no less significant harm than fire.

In offices with expensive electrical equipment, museums, libraries, and marine and aircraft gas fire extinguishing systems are used.

History reference

The non-flammable mixture can be supplied in two ways: modularly, using removable cylinders, or centrally, from a common tank.

According to the volume of extinguishing, automatic gas fire extinguishing installations are local or complete extinguishing. In the first case, the substance is supplied only to the source of ignition (for example, gas fire extinguishing in a server room can only be organized in this way), in the second - around the entire perimeter of the room.

Design, calculation and installation of gas fire extinguishing systems

Installation of a gas fire extinguishing system requires careful observance of all current legislation and full compliance with the requirements of each facility being designed. Therefore, it is better to entrust such a complex and painstaking task to professionals.

When installing such a system, it is necessary to take into account many factors: the number and area of all rooms, the features of the room (such as a false ceiling or false walls), general purpose, humidity characteristics, as well as methods of evacuating citizens in case of an emergency.

In addition, there are some nuances in this case. For example, when installing equipment in a room with high traffic of people, the installation must be performed in such a way that when the fire extinguishing system is triggered, the oxygen concentration in the air remains within the permissible limits.

It must also be remembered that each gas fire extinguishing module must be protected from external factors.

Routine maintenance of gas fire extinguishing systems

In order for gas fire extinguishing installations to function properly during the entire period of operation, they need to be carried out preventive maintenance from time to time. Every month, all components of the system must be checked for their tightness, and fire sensors - for operability.

After each operation of the fire extinguishing system, it is necessary to refuel the gas tanks and reconfigure

All of the above preventive work are carried out directly at the customer's site, that is, they do not require constant reinstallation of the system.

In addition, the routine maintenance of the gas fire extinguishing system includes regular technical examination of the modules. Each gas fire extinguishing module must be checked once every 10-12 years.

What is included in the installation work?

Before installing gas equipment, it is necessary to make sure that the manufacturer has state certificates. It will not be superfluous to check the license of the contractor company that carries out its installation.

Then it is necessary to make sure that the ventilation systems are working, and only then proceed to work.

All modules of the device are combined into a single system responsible for the operation of the device in case of fire, and control over the situation in the room. At this stage, the owner must make sure that the design proposed by the master not only suits him aesthetically, but also does not interfere with the work of the staff.

After the installation of the system, the contracting company draws up test reports and technical documentation for each of its elements.

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Non-state educational institution secondary vocational education College of Law of the International Police Association

Course work

Fire extinguishing agents used in automatic fire extinguishing installations

Completed by: Gorbushin Ilya Nikolaevich

Course 3 group 4411

Specialty: 280703 Fire safety

Head: Peskichev S.V.

Introduction

1. Classification of fire extinguishing agents

1.1 Water installations

1.2 Powder plants

1.3 Gas installations

1.4 Foam plants

1.5 Aerosol plants

1.6 Combined installation

2. Cases in which the installation of automatic fire extinguishing systems is mandatory

2.1 Advantages and disadvantages of automatic fire extinguishing

Conclusion

Bibliographic list

Introduction

Automatic fire extinguishing systems are used to quickly respond to signs of fire and prevent fire. They can be compared to a fire brigade permanently on site.

Automatic fire extinguishing systems can be installed in almost any room. The most relevant locations for such systems are large parking lots. closed type, server rooms, production facilities where there is a possibility of fire during the production process, document archives, etc.

1. Classificationautomaticsystemsfirefighting

Fire extinguishing installations - a set of stationary technical means extinguishing a fire by releasing a fire extinguishing agent. Fire extinguishing installations must ensure the localization or elimination of a fire.

Fire extinguishing installations constructive device subdivided into aggregate and modular.

According to the degree of automation - automatic, automated and manual.

By type of fire extinguishing agent - water, foam, gas, powder, aerosol and combined.

According to the method of extinguishing - into volumetric, surface, locally-volumetric and locally-surface.

1. 1 Waterinstallations

Water installations are sprinkler and deluge. Sprinkler installations are designed for local extinguishing of fires in rapidly flammable premises, for example, wooden ones, and deluge installations are designed to extinguish a fire immediately throughout the facility.

In sprinkler extinguishing systems, the sprinkler (sprinkler) is mounted in a pipeline filled with water, special foam (if the room temperature is above 5°C) or air (if the room temperature is below 5°C). At the same time, the fire extinguishing substance is constantly under pressure. There are combined sprinkler systems in which the supply pipeline is filled with water, and the supply and distribution pipes can be filled with air or water, depending on the season. The sprinkler is closed with a thermal lock, which is a special flask designed for depressurization when a certain ambient temperature is reached.

After the sprinkler is depressurized, the pressure in the pipeline becomes less, due to which the special valve in the control node. After that, the water rushes to the detector, which detects the operation and gives a command signal to turn on the pump.

Sprinkler fire extinguishing systems are used for local detection and elimination of fires with the activation of fire alarms, special warning systems, smoke protection, evacuation management and provision of information about fire sites. The service life of sprinklers that have not worked is ten years, and sprinklers that have worked or are damaged must be completely replaced. During the design of the pipeline network, it is divided into sections. Each of these sections can serve one or several rooms at once, and can also have a separate control unit fire fighting system. An automatic pump is responsible for the working pressure in the pipeline.

Drencher automatic fire extinguishing systems (drencher curtains) differ from sprinkler ones in that they do not have thermal locks. They also have a high water consumption and the possibility of simultaneous operation of all sprinklers. Sprinkler nozzles are of various types: jet with high pressure, two-phase gas-dynamic, with atomization of liquid by impact with deflectors or by interaction of jets. When designing deluge curtains, the following are taken into account: type of deluge, expected pressure, distance between sprinklers and their number, pump power, pipeline diameter, volume of liquid tanks, installation height of deluges.

Drenerme curtains solve the following problems:

localization of the fire;

dividing areas into controlled sectors and preventing the spread of fires, as well as harmful products combustion outside the sector;

· Cooling of technological equipment to acceptable temperatures.

Recently wide application received automatic fire extinguishing systems using water mist. The size of drops after spraying can reach 150 microns. The advantage of this technology is a more efficient flow of water. In the case of extinguishing fires using conventional installations, only a third of the total volume of water is used to extinguish the fire. Fine water extinguishing technology creates a water mist that eliminates fire. This technology allows you to eliminate fires with a high degree of efficiency with rational water consumption.

1.2 Powderinstallations

The principle of operation of such devices is based on extinguishing a fire by supplying a fine powder composition to the fires. According to the current fire safety standards, all public and administrative buildings, technological premises and electrical installations, as well as storage and production premises must be equipped with automatic powder installations.

Installations do not provide a complete cessation of combustion and should not be used to extinguish fires:

Combustible materials prone to spontaneous combustion and smoldering inside the volume of the substance ( sawdust, cotton, grass flour, paper, etc.);

chemicals and their mixtures, pyrophoric and polymer materials prone to smoldering and burning without air access.

1.3 Gasinstallations

purpose gas installations fire extinguishing consists in detecting fires and supplying a special fire extinguishing gas. They use active compositions in the form of liquefied or compressed gases.

Compressed fire extinguishing mixtures include, for example, Argonite and Inergen. All compositions are based on natural gases that are already present in the air, such as nitrogen, carbon dioxide, helium, argon, so their use does not harm the atmosphere. The method of extinguishing with such gas mixtures is based on the substitution of oxygen. It is known that the combustion process is supported only when the oxygen content in the air is not less than 12-15%. When liquefied or compressed gases are released, the amount of oxygen falls below the above figures, which leads to the extinction of the flame. It must be taken into account that a sharp decrease in the level of oxygen inside a room in which people are present can lead to dizziness or even fainting, therefore, when using such fire extinguishing mixtures, evacuation is usually necessary. Liquefied gases used for fire fighting purposes include: carbon dioxide, mixtures and synthesized gases based on fluorine, for example, freons, FM-200, sulfur hexafluoride, Novec 1230. Freons are divided into ozone-friendly and ozone-depleting. Some of them can be used without evacuation, while others can only be used indoors in the absence of people. Gas installations are most suitable for ensuring the safe operation of electrical equipment that is energized. Liquefied and compressed gases are used as fire extinguishing agents.

Liquefied:

freon23;

freon125;

freon218;

freon227ea;

Freon318C;

hexaphosphoric sulfur;

Inergen.

1.4 Foaminstallations

Foam fire extinguishing installations are mainly used to extinguish easily flammable liquids and combustible liquids in tanks, combustible substances and oil products located both inside and outside buildings. Foam APT deluge installations are used to protect local areas of buildings, electrical appliances, transformers. Sprinkler and validity installations of water and foam fire extinguishing They have a fairly close purpose and device. A feature of APT foam installations is the presence of a tank with a foaming agent and dosing devices, with separate storage of the components of the fire extinguishing agent.

The following dosing devices are used:

· Duel pumps that provide the foaming agent to the pipeline;

· Automatic dispensers with a Venturi pipe and a diaphragm-plunger regulator (with an increase in water flow, the pressure drop in the Venturi pipe increases, the regulator provides an additional amount of foam concentrate);

· Ejector -type foam mixers;

· Doster tanks using the pressure difference created by Venturi.

Another distinctive feature of foam fire extinguishing installations is the use of foam sprinklers or generators. There are a number of disadvantages inherent in all water and foam fire extinguishing systems: dependence on water supply sources; the difficulty of extinguishing premises with electrical installations; complexity of maintenance; large, and often irreparable, damage to the protected building.

1.5 Aerosolinstallations

For the first time, the use of aerosol means for extinguishing fires was described in 1819 by Shumlyansky, who used black powder, clay and water for these purposes. In 1846, Kuhn proposed boxes filled with a mixture of saltpeter, sulfur and coal (smoky powder), which he recommended to throw into a burning room and tightly close the door. Soon the use of aerosols was discontinued due to their low efficiency, especially in leaky rooms.

Volumetric aerosol fire extinguishing installations do not provide a complete cessation of combustion (fire suppression) and should not be used to extinguish:

fibrous, loose, porous and other combustible materials prone to spontaneous combustion and (or) smoldering inside the layer (volume) of the substance (sawdust, cotton, grass flour, etc.);

chemicals and their mixtures, polymeric materials prone to smoldering and burning without air access;

metal hydrides and pyrophoric substances;

metal powders (magnesium, titanium, zirconium, etc.).

It is forbidden to use the settings:

in rooms that cannot be left by people before the generators start working;

premises with a large number of people (50 people or more);

Indoors of buildings and structures III and below the degree of fire resistance according to SNiP 21-01-97 installations using fire-extinguishing aerosol generators having a temperature of more than 400 ° C outside the zone 150 mm away from outer surface generator.

1.6 Combinedinstallation

Automatic combined fire extinguishing installation (AUKP) - an installation that provides fire extinguishing with the help of several fire extinguishing agents.

Usually AUKP is a combination of two individual fire extinguishing installations that have a common object of protection and an operation algorithm (for example, combinations of fire extinguishing agents: powder-foam medium multiplicity; low expansion foam powder; powder - sprayed water; GAZ-PENI of medium multiplicity; low expansion gas-foam; gas-sprayed water; gas-gas; powder-gas). The choice of a combination of fire extinguishing agents should take into account the features of fire extinguishing: the rate of fire development, the presence of heated protected surfaces, etc.

2. casesinwhichinstallationautomaticsystemsfirefightingobligatory

fire extinguishing sprinkler drecking automatic

In accordance with the current fire safety standards, the above systems must be equipped without fail:

· data centers, server rooms, data centers - data processing centers, as well as other premises intended for storage and processing of information and museum valuables;

· Closed underground car parking; aboveground parking having more than one floor;

· One -story buildings built from the lungs metal structures with the use of combustible heaters: for public purposes - with an area of over 800 m2, for administrative purposes - with an area of over 1200 m2;

Buildings selling flammable and combustible liquids and materials, except for those selling packages up to 20 liters;

buildings with a height of more than 30 meters (except for industrial buildings included in the categories fire hazard“G” and “D”, as well as residential buildings);

buildings of trade enterprises (except for those engaged in trade and storage of products made from non-combustible materials): over 200 m2 - in the basement or basement floors, more than 3500 m2 - in the ground part of the building;

· all one-story exhibition halls with an area of more than 1000 m2, as well as more than two floors;

· Clinical and concert halls with a capacity of more than 800 seats;

· Other buildings and structures according to fire safety standards.

2.1 Advantagesandlimitationsautomaticfirefighting

Not all substances used for fire extinguishing are safe for the human body: some contain chlorine and bromine in their composition, which adversely affect internal organs; others dramatically lower the degree of oxygen in the air, which can cause suffocation and lead to loss of consciousness; Still others annoy the respiratory and visual systems of the body.

Elimination of fires with water is one of the most effective and safe methods for most all cases. However, this method of fighting fires requires a large amount of water needed to extinguish the fire. It is necessary to build capital engineering structures for uninterrupted water supply. In addition, water during extinguishing can cause serious material damage.

Among the advantages of gas installations, it is worth noting the following:

Extinguishing fires with their help does not lead to corrosion of equipment;

the consequences of their use are easily eliminated with the help of standard ventilation of the room;

They are not afraid of rising temperatures and do not freeze.

Along with the above advantages, the disadvantage of some gases is their rather high danger to humans. However, recently scientists have developed completely safe gaseous substances, for example, Novec 1230. In addition to safety for human health, the undeniable advantage of this substance is its harmlessness to the atmosphere. Novec 1230 is completely safe for the ozone layer, does not contain chlorine and bromine, its molecules completely break down under the influence of ultraviolet radiation in about five days. In addition, it is not dangerous for any property. This substance is certified, including compliance with fire safety rules and regulations, sanitary and epidemiological standards, and can be used throughout Russia. An automatic fire extinguishing system using Novec 1230 is able to quickly eliminate fires of various complexity classes.

The use of powder systems for extinguishing fires is absolutely harmless to the human body. The powder is very easy to use and costs very little. It does not harm the premises and property, but has a short shelf life.

Conclusion

The purpose of using automatic fire extinguishing installations is to localize and extinguish fires, save the lives of people and animals, as well as real and movable property. The use of such tools is the most effective method fire fighting. Unlike manual fire extinguishers and alarm systems, they create all the necessary conditions for effective and prompt localization of fires with minimal risk to health and life.

Bibliographiclist

1. Federal Law No. 123 of July 22, 2008 " Technical regulation on fire safety requirements"

2. Smirnov N.V., Tsarichenko S.G., Zdor V.L. and others. “Regulatory and technical documentation on the design, installation and operation of fire extinguishing installations, fire alarms and smoke removal systems” M., 2004;

3. Baratae A.N. "Fire and explosion hazard of substances and materials and means of extinguishing them" M., 2003.

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