Substances are divided according to their flammability. Types, composition and properties of solid combustible substances and materials. Aerated concrete blocks for wall insulation

Non-flammable substances and materials

"...1) non-flammable - substances and materials that are unable to burn in air. Non-combustible substances can be fire and explosive (for example, substances that release flammable products when interacting with water, air oxygen or with each other);..."

Source:

Federal Law of July 22, 2008 N 123-FZ (as amended on July 10, 2012) “on fire safety requirements”

"...- non-flammable material - a material that, when heated to 750 `C, does not burn and does not emit flammable gases in quantities sufficient for their self-ignition;..."

Source:

Ministry of Transport of the Russian Federation dated 02/12/2004 N 12 "On fire safety rules when carrying out hot work on ships located at the berths of seaports and ship repair enterprises"

Official terminology. Akademik.ru. 2012.

See what “Non-combustible substances and materials” are in other dictionaries:

non-flammable (non-combustible) substances and materials- Substances and materials that are not capable of burning in air. Non-flammable substances can be fire-explosive (for example, oxidizers or substances that release flammable products when interacting with water, air oxygen or with each other) [GOST... ... Technical Translator's Guide

Dangerous substances- substances with potential danger to humans. Due to the potential danger of causing a fire, increasing fire hazards, poisoning the habitat (air, water, soil, flora, fauna, etc.), affecting humans... ... Russian encyclopedia of labor protection

Fireproof materials- materials whose reduced flammability is achieved by special treatment (fire protection). Fire protection methods include: applying a layer of non-flammable or low-flammability substances to the surface of materials; introduction to the composition... ... Great Soviet Encyclopedia

Fire safety- This article should be Wikified. Please format it according to the rules for formatting articles... Wikipedia

Fire safety- Fire safety is the state of protecting individuals, property, society and the state from fires. “Fire safety” is an illiterate phrase that comes up to mean “fire safety.” Contents 1... ...Wikipedia

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Flammability- the ability of a substance, material, product to burn independently. According to G., substances, materials, products, and structures are divided into: 1) flammable substances capable of spontaneous combustion after removal of the ignition source; 2) low-flammability capable of... ... Encyclopedia of technology

COMBUSTION- An exothermic reaction that occurs under conditions of its progressive self-acceleration. Based on flammability, substances and materials are divided into three groups: non-flammable (non-combustible) substances and materials that are not capable of burning in air. Non-flammable substances... ... Comprehensive provision of security and anti-terrorist protection of buildings and structures

flammability Encyclopedia "Aviation"

flammability- flammability the ability of a substance, material, product to burn independently. According to G., substances, materials, products, structures are divided into: 1) flammable capable of spontaneous combustion after removal of the ignition source;... ... Encyclopedia "Aviation"

COMBUSTION OF SOLIDS AND MATERIALS

When extinguishing fires, you most often have to deal with the combustion of solid flammable substances and materials (SCM). Therefore, knowledge of the mechanisms of occurrence and development of combustion of THMs is important when studying the discipline “Theory of Combustion and Explosion”.

Most THMs belong to class of organic substances(see Fig. 5.1), consisting mainly of carbon, hydrogen, oxygen and nitrogen. Many organic substances may contain chlorine, fluorine, silicon and other chemical elements, and most of the constituent elements of THMs are flammable.

Significantly smaller amounts of THMs belong to class of inorganic substances, many of which are also fire and explosion hazards. There is a well-known fire hazard, for example, magnesium, sodium, which is prone to spontaneous combustion upon contact with water. In addition, extinguishing metal fires is associated with significant difficulties, in particular, due to the unsuitability of most fire extinguishing agents for these purposes.

It is necessary to take into account that when crushing THMs, their fire and explosion hazard increases sharply, for example, wood, grain, coal in the state of dust become explosive. Wood dust in a workshop for the production of fibreboards begins to explode already at a concentration of 13-25 g/m3; wheat flour in mills - at a concentration of 28 g/m3, coal dust in mines - at 100 g/m3. Metals, when ground into powder, spontaneously ignite in air. Other examples can be given.

The composition of THMs influences the characteristics of their combustion (see Table 5.1). So, cellulose materials, in addition to carbon and hydrogen, contain oxygen (up to 40-46%), which participates in combustion in the same way as air oxygen. Therefore, cellulose materials require a significantly smaller volume of air for combustion than substances that do not contain oxygen (plastics).

Rice. 5.1. Classification of solid combustible substances and materials

This also explains the relatively low heat of combustion of cellulose materials and their tendency to smolder. Among them, the most notable are fibrous(wool, linen, cotton), the cavities and pores of which are also filled with air, which promotes their combustion. In this regard, they are extremely prone to smoldering; the insulation extinguishing method is ineffective for them; moreover, in real conditions they practically cannot be extinguished. The combustion of such substances occurs without the formation of soot.

A characteristic property of other cellulose materials is their ability to decompose when heated to form flammable vapors, gases and carbonaceous residue. Thus, with the decomposition of 1 kg of wood, 800 g of flammable gaseous decomposition products and 200 g of charcoal are formed, with the decomposition of 1 kg of peat - 700 g of volatile compounds, and cotton - 850 g. In addition to the nature of the fuel, the amount and composition of volatile substances released depends on the temperature and the heating mode of this substance.

Table 5.1.

Composition of some cellulosic materials

Based on their flammability, building finishing materials are divided into three main groups:

Non-combustible materials- Materials that, under the influence of an ignition source (sparks, fire, electric current, high temperature, chemical reaction, etc.) do not ignite or burn (natural and artificial inorganic materials - stone, concrete, reinforced concrete, etc.);

Difficult to combustible materials- Materials that burn under the influence of ignition sources but are incapable of full independent combustion (asphalt concrete, plasterboard, wood impregnated with antipyrites agents, fiberglass, fiberglass, etc.);

Combustible materials- Materials and substances that will remain burning after removal of the ignition source.

Use of non-combustible materials

Non-combustible materials are used in construction and repair for finishing floors, partitions, walls and ceilings of buildings and premises, as well as for cladding facades. The main characteristic of these materials is their resistance to high temperatures.

The INFRACHIM company offers consumers a wide range of innovative non-combustible building materials that have successfully passed all laboratory studies and tests and are confirmed by all necessary certificates and sanitary and epidemiological reports.

TPK INFRACHIM materials can be used in crowded places; they are environmentally friendly materials that are absolutely safe for humans and animals. They do not emit poisonous or toxic substances when heated and have a number of advantages over competitors' products.

Non-combustible materials and their features

The non-flammable materials offered by our company are easy to use, reliable and durable. These products have low indicators for such parameters as change in shape in a wet state, water absorption, change in size after heating, thermal conductivity of the material, and high indicators for the following characteristics: strength and bending in a dry/moisture-saturated state, impact strength, tensile strength , density. The materials, as a rule, are lightweight, which makes them easy to transport and install. Most materials have a perfectly smooth surface, both on the inside and outside.

Non-combustible materials are intended for construction and finishing work indoors and outdoors. They are used for finishing work on almost any building, industrial premises, hotels, restaurants, hostels, water parks, administrative buildings, etc., etc.

Using non-combustible finishing materials, it is possible to carry out external cosmetic work, i.e. finishing external walls, facades, pediments, cornices, columns, etc. In addition, the products offered are ideal as a basis for laying metal tiles or soft roofs. These materials are quite hard, which allows them to have good heat-insulating and sound-proofing qualities. They are widely used in the construction of ventilated facades of buildings.

Non-combustible finishing materials have a relatively low weight, which makes them easy to transport without the use of special expensive equipment, and also to be installed by finishing crew workers. They will perfectly retain their appearance and last for many years.

A short excursion into history:

About the cause of fires in the Middle Ages, for example, the same thing was always said: “by chance” and “by the will of God.” The fact that fire was associated with the wrath of God is extremely characteristic of medieval consciousness. Medieval people had very little knowledge about the world around them, but thanks to this naivety and lack of education, their lives were full of miracles.

Today our knowledge is sufficient not only to determine the causes of the fire, but also to, if not prevent it (“the will of chance” is still relevant today), then at least optimize its elimination and minimize the destructive consequences and do not rely on a miracle, but create it yourself.

A common cause of fire is a short circuit of the power cable and its fire, which quickly spreads along the cable route. Imagine a typical industrial plant. If a fire spreads at a temperature of 500 degrees, softening and collapse of seemingly strong metal structures can occur in a matter of minutes. And even concrete cannot withstand temperatures of 1000 degrees. That is, the task is to prevent the spread of fire if it has already appeared.

The cause of the fire at the Ostankino TV tower was an excess of the permissible load on the feeders - cables transmitting a high-power signal from the equipment to the antenna - the excessive load caused overheating and fire of the cables inside the tower. The total damage from the fire at the Ostankino TV tower is estimated at hundreds of millions of dollars, and the moral damage to television viewers who were left “blind” and deprived of a daily dose of information is almost impossible to assess. What could stop the spread of fire if a fire did occur? Miracle? No! Non-flammable polymer materials.

Many countries have already adopted special restrictions on the use of flammable polymer materials in civil and industrial construction, in the production and operation of vehicles (airplanes, cars, buses, trolleybuses, trams, railway cars, ships), in power plants and in electrical networks, in space and cable industry. So, reducing the flammability and combustibility of polymers and creating fireproof materials is an urgent problem for polymer chemistry. This task is complicated by another urgent requirement of our time - the environmental friendliness of fire retardant additives - fire retardants.

Fire retardants prevent the combustion of polymer materials and are among the most important components of plastics. When polymer materials burn, complex physical and chemical processes occur inside and on the surface of the condensed phase, as a result of which the polymer is converted into combustion products heated to a high temperature.

Features of storage of non-combustible materials

These materials should be stored in dry rooms with normal humidity levels. If these basic storage conditions are observed, the products will perfectly retain their appearance and last for many years.

Regarding the supply of non-combustible materials, please contact the company's sales department by contact numbers.

FIRE TACTICS

LECTURE NOTES

Topic: Fire and its development

Arkhangelsk, 2015

Literature:

2. Federal Law of July 22, 2008 N 123 Federal Law “Technical Regulations on Fire Safety Requirements”.

3. Terebnev V.V., Podgrushny A.V. Fire tactics - M.: - 2007

I'M WITH. Pozik. RTP Directory. Moscow. 2000

5. Ya.S. Pozik. Fire tactics. Moscow. Stroyizdat. 1999

6. M.G.Shuvalov. Basics of firefighting. Moscow. Stroyizdat. 1997

Study questions:

1 question General concept of the combustion process. Conditions necessary for combustion (combustible substance, oxidizer, ignition source) and its cessation. Combustion products. Complete and incomplete combustion. Brief information about the nature of combustion of solid combustible materials, flammable and combustible liquids, gases, flammable mixtures of vapors, gases and dusts with air

2. Question

General concept of the combustion process. Conditions necessary for combustion (combustible substance, oxidizer, ignition source) and its cessation. Combustion products. Complete and incomplete combustion. Brief information about the nature of combustion of solid combustible materials, flammable and combustible liquids, gases, flammable mixtures of vapors, gases and dusts with air.

Combustion is any oxidation reaction in which heat is released and the glow of burning substances or their decomposition products is observed.

For combustion to occur, certain conditions are necessary, namely the combination in one place at one time of three main components:

· flammable substances, in the form of combustible materials (wood, paper, synthetic materials, liquid fuel, etc.);

· an oxidizing agent, which most often is air oxygen when burning substances; in addition to oxygen, oxidizing agents can be chemical compounds containing oxygen in their composition (saltpeter, perchlorites, nitric acid, nitrogen oxides) and individual chemical elements: chlorine, fluorine, bromine;

· an ignition source that constantly and in sufficient quantities enters the combustion zone (spark, flame).

ignition source

O 2 flammable substance

The absence of one of the listed elements makes it impossible for a fire to occur or leads to the cessation of combustion and the elimination of the fire.

Most fires involve the combustion of solid materials, although the initial stage of a fire may involve the combustion of liquid and gaseous flammable substances used in modern industrial production.

Ignition and combustion of most flammable substances occurs in the gas or vapor phase. The formation of vapors and gases from solid and liquid flammable substances occurs as a result of heating. In this case, liquids boil with evaporation, and materials volatilize, decompose, or pyrolyze from the surface of solids.

Solid flammable substances behave differently when heated:

· some (sulfur, phosphorus, paraffin) melt;

· others (wood, peat, coal, fibrous materials) decompose with the formation of vapors, gases and solid coal residues;

· still others (coke, charcoal, some metals) do not melt or decompose when heated. The vapors and gases released from them mix with air and oxidize when heated.

The glow of the flame occurs because light is emitted by hot carbon particles that do not have time to burn.

A mixture of a flammable substance with an oxidizer is called a combustible mixture. Depending on the state of aggregation of the combustible mixture, combustion can be:

Homogeneous (gas-gas);

Heterogeneous (solid-gas, liquid-gas).

In homogeneous combustion, the fuel and oxidizer are mixed; in heterogeneous combustion, they have an interface.

Depending on the ratio of oxidizer and combustible substance in the flammable mixture, two types of combustion are distinguished:

· complete combustion - combustion of lean mixtures, when the oxidizer is much larger than the combustible substance and the resulting products are not capable of further oxidation - carbon dioxide, water, nitrogen oxides and sulfur.

· incomplete combustion - combustion of rich mixtures, when the oxidizer is significantly less than the combustible substance, incomplete oxidation of the decomposition products of substances occurs. Products of incomplete combustion are carbon monoxide, alcohols, ketones, acids.

A sign of incomplete combustion is smoke, which is a mixture of vapor, solid and gaseous particles. In most cases, fires involve incomplete combustion of substances and strong smoke emission.

Combustion can occur in several ways:

· flash - rapid combustion of a combustible mixture, not accompanied by the formation of compressed gases. It does not always lead to fire, since the heat generated is not enough;

· fire – the occurrence of combustion under the influence of an external ignition source;

· ignition – ignition using a flame;

· spontaneous combustion – the occurrence of combustion under the influence of an internal ignition source (thermal-exothermal reactions).

· spontaneous combustion – spontaneous combustion with the appearance of a flame.

Characteristics of flammable substances

Substances that can burn independently after removing the source of ignition are called combustible, in contrast to substances that do not burn in air and are called non-flammable. An intermediate position is occupied by difficultly combustible substances that ignite when exposed to an ignition source, but stop burning after the latter is removed.

All flammable substances are divided into the following main groups.

1. Combustible gases (GG)- substances capable of forming flammable and explosive mixtures with air at temperatures not exceeding 50° C. Combustible gases include individual substances: ammonia, acetylene, butadiene, butane, butyl acetate, hydrogen, vinyl chloride, isobutane, isobutylene, methane, carbon monoxide, propane , propylene, hydrogen sulfide, formaldehyde, as well as vapors of flammable and combustible liquids.

2. Flammable liquids (flammable liquids)- substances capable of burning independently after removal of the ignition source and having a flash point not higher than 61° C (in a closed crucible) or 66° (in an open crucible). These liquids include individual substances: acetone, benzene, hexane, heptane, dimethylforamide, difluorodichloromethane, isopentane, isopropylbenzene, xylene, methyl alcohol, carbon disulfide, styrene, acetic acid, chlorobenzene, cyclohexane, ethyl acetate, ethylbenzene, ethyl alcohol, as well as mixtures and technical products gasoline, diesel fuel, kerosene, white alcohol, solvents.

3. Flammable liquids (FL)- substances capable of burning independently after removal of the ignition source and having a flash point above 61° (in a closed crucible) or 66° C (in an open crucible). Flammable liquids include the following individual substances: aniline, hexadecane, hexyl alcohol, glycerin, ethylene glycol, as well as mixtures and technical products, for example, oils: transformer oil, vaseline, castor oil.

4. Combustible dusts (GP)- solids in a finely dispersed state. Combustible dust in the air (aerosol) can form explosive mixtures with it. Dust (aerogel) settled on walls, ceilings, and equipment surfaces is a fire hazard.

Combustible dusts are divided into four classes according to the degree of explosion and fire hazard.

Class 1 - the most explosive - aerosols with a lower concentration limit of ignition (explosiveness) (LCEL) of up to 15 g/m 3 (sulfur, naphthalene, rosin, mill dust, peat, ebonite).

Class 2 - explosive - aerosols with an LEL value from 15 to 65 g/m 3 (aluminum powder, lignin, flour dust, hay dust, shale dust).

3rd class - the most fire hazardous - aerogels with an LFL value greater than 65 g/m 3 and a self-ignition temperature of up to 250 ° C (tobacco, elevator dust).

4th class - fire hazardous - aerogels with an LFL value greater than 65 g/m 3 and a self-ignition temperature greater than 250 ° C (sawdust, zinc dust).

Below are some characteristics of flammable substances necessary for predicting emergency situations.

Indicators of explosion and fire hazard of flammable gases and vapors of flammable and combustible liquids

Table 1.

Flash point- the lowest temperature of a liquid at which a steam-air mixture is formed near its surface, capable of flaring up from a source and burning, without causing a stable combustion of the liquid.

Upper and lower explosive concentration limits(ignition) - respectively, the maximum and minimum concentration of flammable gases, vapors of flammable or combustible liquids, dust or fibers in the air, above and below which an explosion will not occur even if there is a source of initiation of the explosion.

The aerosol is capable of exploding when solid particle sizes are less than 76 microns.

Upper explosive limits dusts are very large and are practically difficult to reach indoors, so they are not of interest. For example, the VCPV of sugar dust is 13.5 kg/m 3 .

BB- explosive substance - a substance capable of explosion or detonation without the participation of oxygen in the air.

Auto-ignition temperature- the lowest temperature of a combustible substance at which a sharp increase in the rate of exothermic reactions occurs, ending in the occurrence of flaming combustion.

General concept of fire. Brief description of the phenomena occurring during a fire. Hazardous Fire Factors and their secondary manifestations. Classification of fires. Gas exchange in a fire. Conditions conducive to the development of fire, the main ways of fire spread.

Fire – uncontrolled combustion causing material damage, harm to the life and health of citizens, and the interests of society and the state. (No. 69-FZ “On Fire Safety” dated December 21, 1994).

By fire uncontrolled combustion is considered outside a special focus causing material damage (RTP directory, P.P. Klyus, V.P. Ivannikov).

Fire is a complex physical and chemical process, which, in addition to combustion, includes general phenomena that are characteristic of any fire, regardless of its size and place of origin (mass and heat transfer, gas exchange, smoke formation). These phenomena are interconnected and develop in time and space. Only eliminating the fire can lead to their cessation.

General phenomena can lead to the emergence of particular phenomena, i.e. those that may or may not occur in fires. These include: explosions, deformation and collapse of technological devices and installations, building structures, boiling or release of petroleum products from tanks, etc.

A fire is also accompanied by social phenomena that cause not only material but also moral damage to society. These include death, thermal injuries, poisoning by toxic combustion products, and panic. This is a special group of phenomena that causes significant psychological overload and stress in people.

Signs of a fire:

– combustion process;

– gas exchange;

– heat exchange.

They change in time, space and are characterized by fire parameters.

The main factors characterizing the possible development of the combustion process in a fire include: fire load, mass burnout rate, linear speed of flame propagation over the surface of burning materials, intensity of heat release, flame temperature, etc.

Under fire load understand the mass of all flammable and slow-burning materials located indoors or in open space, related to the floor area of ​​the room or the area occupied by these materials in open space (kg/m2).

Burnout rate– loss of mass of material (substance) per unit of time or combustion (kg/m 2 s).

Linear speed of combustion propagation– a physical quantity characterized by the translational movement of the flame front in a given direction per unit time (m/s).

Under the temperature of a fire in fences understand the average volumetric temperature of the gas environment in the room.

Under the temperature of fire in open spaces– flame temperature.

During a fire, gaseous, liquid and solid substances are released. They are called combustion products, i.e. substances formed as a result of combustion. They spread in a gaseous environment and create smoke.

Smoke– a dispersed system of combustion products and air, consisting of gases, vapors and hot particles. The volume of smoke released, its density and toxicity depend on the properties of the burning material and on the conditions of the combustion process.

Smoke formation in a fire - the amount of smoke, m 3 /s, emitted from the entire area of ​​the fire.

Smoke concentration– the amount of combustion products contained per unit volume of the room (g/m3, g/l, or in volume fractions).

Fire area(S P)– the area of ​​projection of surface combustion of solid and liquid substances and materials onto the surface of the earth or floor of the room.

Fire area has its own borders: perimeter and front.

Fire perimeter (P P) is the length of the outer boundary of the fire area.

Fire front (F P) – part of the fire perimeter in the direction of which combustion spreads.

Fire area shapes

Circular the shape of the fire area (Fig. 2) occurs when a fire occurs in the depths of a large area with a fire load and, in relatively calm weather, spreads in all directions with approximately the same linear speed (timber warehouses, grain tracts, combustible coatings of large areas, industrial, as well as large warehouses, etc.).

Corner shape (Fig. 3, 4 ) characteristic of a fire that occurs at the border of a large area with a fire load and spreads inside the corner under any meteorological conditions. This form of fire area can occur on the same objects as the circular one. The maximum angle of the fire area depends on the geometric shape of the area with the fire load and the location of the combustion. Most often, this form is found in areas with an angle of 90° and 180°.

Rectangular the shape of the fire area (Fig. 5) occurs when a fire occurs on the border or in the depths of a long section with a flammable load and spreads in one or several directions: downwind - with a larger one, against the wind - with a smaller one, and in relatively calm weather with approximately the same linear speed (long buildings of small width of any purpose and configuration, rows of residential buildings with outbuildings in rural settlements, etc.).

Fires in buildings with small rooms take on a rectangular shape from the start of combustion. Ultimately, as combustion spreads, the fire can take the shape of a given geometric section (Fig. 6)

The shape of the area of ​​a developing fire is the main one for determining the design scheme, the directions of concentration of forces and extinguishing means, as well as the required quantity of them under the appropriate parameters for carrying out combat operations. To determine the design scheme, the real shape of the fire area is reduced to figures of regular geometric shape (Fig. 7 a, b, in a circle with radius R(with a circular shape), a sector of a circle with a radius R and angle α (with angular shape), rectangle with side width a and length b(with a rectangular shape).

Fig.7. Calculation schemes for fire area shapes

A) circle; b) rectangle; c) sector

Circular shape of the fire area

Fire area – S P = pR 2 S P = 0.785 D 2

Fire perimeter – P P = 2pR

Fire front – Ф П = 2pR

Angular fire shape

Fire area – S P = 0.5 aR 2

Fire perimeter – P П = R(2+a)

Fire front – Ф П = aR

Linear velocity of propagation – V L = R/t

Rectangular fire shape

Fire area – S P = a b.

With development in two directions S P = a (b 1 + b 2)

Fire perimeter – P P = 2 (a+b).

Development in two directions P P = 2)