As mentioned above, the use of wetting agents significantly improves the fire extinguishing properties of water and reduces extinguishing time. Using surfactant solutions, fire departments seem to double the volume of water delivered to fires. Reducing the extinguishing Bpv prevents the formation of large and protracted fires and significantly reduces fire losses.

The organization of the use of wetting agents by garrison fire departments should be handled by service and training departments (departments) together with fire-technical stations. The surfactants mentioned above are produced by industry and fire departments are routinely supplied with them or purchased from enterprises that use them in technological processes.

Currently, wetting agents are used in large quantities in textile enterprises, plants and factories involved in cleaning hard surfaces, flotation and beneficiation of ores, degreasing and tanning leather, dyeing furs, preparing emulsions, pesticides, as well as in enterprises producing varnishes and paints, paper , synthetic fibers and films, synthetic rubbers and other polymers. Wetting agents are widely used in the petroleum and chemical industries.

Almost all of the surfactants under consideration are liquids with varying viscosities; only sulfonol NP-1, the wetting agent NB and sulfonate of some brands are solids with varying degrees of solubility. Sulfonol NP-1 should be prepared only in the form of a solution of working concentration. From the wetting agent NB and sulfonate you can obtain concentrated solutions, which can then be sucked into water either by portable ejectors or by fire truck mixers. Emulsifier OP-4, auxiliary substance OP-7, wetting agent DB are viscous liquids. They are pre-diluted with water and then mixed into the water. The remaining substances are liquids , mix well with water. They are easily sucked up by jetting devices. Surfactants, with the exception of OP-4, OP-7 and the wetting agent DB, in concentrations exceeding the optimal ones, when supplied from barrels type! GVP can form foam of increased expansion, and OG1 4, OP-7 and DB are low-expansion foam. Therefore, they can be exported in concentrated form in non-draining barrels or in fire truck tanks. to and

If you use the stationary air-foam mixer available on the main fire trucks to prepare the working solution, then the concentration of the wetting agent in the solutions taken out to the fire can be 25-50 times higher than the working one. Such a wide range of concentrations is explained by the different solubility of wetting agents, the viscosity of concentrated solutions and the ability of the mixer to suck up different amounts of solution.

To prepare a working solution in a fire using this method, it is necessary to first tar the mixer to supply a solution of optimal concentration through barrel B. From a foaming agent tank with a capacity of 150 liters, which is filled with a wetting agent that is highly soluble in water, for example, sodium sulfonate, you can get up to 7000 liters working solution.

To prepare concentrated solutions (over 10%), all pastes and most solid and liquid surfactants (OP-7, OP-10, DB) should be dissolved with stirring in warm (40-60 °C) water. If the dissolution time is unlimited, then the water is not heated, and the mixture is stirred for a long time until a solution is obtained.

However, when using a foam concentrate tank for transporting concentrated solutions of wetting agents, the possibility of using air-mechanical foam for extinguishing large quantities of flammable liquids in a fire is excluded. Although aqueous solutions of wetting agents, as well as foaming agent PO-1 and others, are capable! form air-mechanical foam, their fire extinguishing properties do not always meet the requirements. Therefore, in fire departments in the exit area of ​​which there are oil depots or facilities where flammable liquids are used, foam agent should be removed to fires. In fire departments serving facilities for the processing or production of fibrous materials, it is advisable to deliver a concentrated wetting solution in tank trucks. Working solutions for almost all substances can be prepared directly in tanks.

Wetting solutions prepared for fires in tank trucks are used mainly for feeding the first barrel. Extinguishing practice shows that one tanker with a wetting solution is, as a rule, sufficient to eliminate an uninitiated fire and localize a developed one. Considering the high wetting ability of surfactant solutions, it is necessary to use only slotted hoses for their supply. When laying a hose line, it is necessary to provide a supply of it, since a wetting solution from one tanker can extinguish a fire area 2-2.5 times larger than with water, and therefore, linemen move considerable distances from the initial position.

All solid materials that can be extinguished with water can be extinguished with wetting solutions. A particularly high effect is observed when extinguishing cellulose materials (cotton, wood, fabrics, paper, etc.), which are the main combustible materials in fires in residential, administrative, medical, agricultural and other buildings. Therefore, fires in these buildings are extinguished with wetting solutions with a lower supply intensity and faster than with water. In this regard, it is recommended to use overlapping trunks with a spray diameter of no more than 13 mm. However, extinguishing practice shows that in order to reduce the wetting solution that is excessively spilled during fires, it is advisable to use trunks with a smaller spray diameter. When using barrels with a 13 mm spray, they must be blocked after quickly processing burning surfaces, during dismantling of burning materials, when stopping, while moving, or changing the positions of the barrels. Indoor fires should be extinguished with spray jets, since this reduces the intensity of the solution supply and lowers the temperature and smoke level in the burning room. Continuous jets extinguish fires when, due to the high temperature in the room, it is impossible to get close to the burning object. The jets must be quickly moved to the burning surface, trying to process it as quickly as possible.

When processing cellulose materials with a solution, a small area of ​​smoldering may remain. In this case, the solution should not be applied to it, since it will go out when the solution penetrates. The intensity of supply p.-icrnopn smlknnl ii.i extinguishing with cellulose material (wood, fabric, paper, hay, etc.) can be taken equal to 0.03-0.05 l/(m 2 -s), i.e. .more than 2 pa i.i less than for the pod. Cotton, hemp, soot and other similar substances cannot be extinguished with water; cotton must be disassembled and spilled with water. For these substances, the intensity of supply of surfactant solutions (based on the results of extinguishing fires) should be taken as 0.05-0.07 l/(m 2 -s), and if the surfactant concentration for extinguishing cellulose materials can be optimal, determined in laboratory conditions, then for fibrous materials it should be increased by 1.3-2 times.

General information

As a fire extinguishing agent, water poorly wets solid materials due to high surface tension (72.8-103 J/m2), which prevents its rapid distribution over the surface, penetration deep into burning solid materials and slows down cooling.

Equipment "Pyrocool"
represents
combined fire nozzle
with surfactant cartridge "Pyrocool" www.pto-pts.ru PTS LLC - Equipment "Pyrocool".

To reduce surface tension and increase wetting ability, add surfactants (Surfactant). In practice, surfactant solutions are used ( wetting agents), the surface tension of which is 2 times less than that of water. The optimal wetting time is 7...9 s. The concentrations of wetting agents in water corresponding to this time are considered optimal and are recommended for extinguishing. The use of wetting solutions makes it possible to reduce water consumption by 35...50% and by 20...30%, which ensures extinguishing with the same volume of fire extinguishing agent over a larger area. Recommended concentrations of wetting agents (%) in aqueous solutions for extinguishing fires are given in table 1. Terebnev V.V. RTP Directory, . Table 1. Recommended concentrations of wetting agents

Wetting agent	Optimal concentration (% to water)
Wetting agent DB	0,2...0,25
Sulfanol
NP-1	0,3...0,5
NP-5	0,3...0,5
B(wetting agent)	1,5...1,8
Nikal NB	0,7...0,8
Excipient
OP-7	1,5...2,0
OP-8	1,5...2,0
Emulsifier OP-4	1,95...2,1
Foaming agent
BY 1	3,5...4,0
PO-1D	6,0...6,5

The working concentration of wetting agents is, as a rule, from 0.1% to 3% GOST R 50588-2012 “Foaming agents for extinguishing fires. General technical requirements and test methods" .

Surfactant molecules, as a rule, consist of long non-polar and short polar parts. Due to their amphiphilic structure, surfactants are concentrated at the air-liquid interface, with the polar part of the molecule (hydrophilic) dissolved in water, and the non-polar (hydrophobic) part facing the air. Thanks to this, the wetting agent becomes an intermediary of contact between water molecules and molecules of a difficult-to-wet solid hydrophobic substance. Good wetting and spreading is possible at high adhesion(when the molecular nature of the liquid and solid are close) and at low cohesion(when the surface tension of the liquid is low).

When extinguishing with a wetting agent solution The fire extinguishing efficiency of water increases by 1.5-2 times.

Previously, when in Russia the main foaming agents used to extinguish fires were protein foaming agents with poor wetting ability, along with foaming agents, individual biologically non-degradable chemical compounds (NB, CB, OP-7, OP-10, etc.) were produced as wetting agents. . Currently, the role of a wetting agent is performed by domestic general purpose foaming agents (PO-ZNP, PO-6TS, TEAS, etc.), which are produced in liquid form and can be used to produce foam.

In Russia, standard testing of wetting ability and selection of the working concentration of the foaming agent are carried out according to GOST R 50588-2012 “Foaming agents for extinguishing fires. General technical requirements and test methods" and consist in determining the time of wetting the hydrophobic fabric with the working solution. FIRE SAFETY. ENCYCLOPEDIA. .

Physical properties of wetting agents

The main physical property of wetting solutions is a decrease in surface tension, which improves the wetting ability of water.

The surface tension of water (72.58 dynes*cm -1 compared to other liquids is relatively high (for example, for ethyl alcohol it is 22.03 dynes*cm -1 for chloroform 27.10 dynes*cm -1) Surface tension is due to the fact that that the molecules located inside the liquid are subject to equal forces of attraction from all sides, while molecules located on the surface are attracted only inward, since the resulting force is directed downward.

From the above laws it follows that water tends to reduce its surface, so a drop of water takes the shape of a ball. However, when a wetting agent is added to the water, the surface tension decreases and the drop loses its spherical shape.

The wetting agent molecules are adsorbed on the surface of the water and concentrated to form a monomolecular layer.

Substances that are difficult to wet (for example, rubber, coal dust or crust dust) are attracted by the hydrophobic part of the molecule. The hydrophilic part is directed into the water, due to which the wetting agent becomes an intermediary of contact between water molecules and molecules of a difficult-to-wet substance G. Schreiber, P. Porst, fire extinguishing agents. Chemical and physical processes during combustion and extinguishing, Moscow, Stroyizdat, 1975.

Fire extinguishing effectiveness of wetting agents

Some hard materials (for example, rubber, coal dust, wood flour, fibrous materials, peat) either cannot be extinguished at all with water without a wetting agent, or are extinguished with difficulty, i.e. with high water consumption.

When extinguishing a smoldering fire, water with a wetting agent supplied to the combustion site first of all localizes the combustion, preventing the appearance of gas in the flame zone. The wetting solution penetrates a cooled fire with a wide front and extinguishes it more intensely than water without a wetting agent. This process is only possible when the cooling is so strong that the wetting solution penetrates without evaporating. In fire zones where water evaporates quickly and has no cooling effect, the fire extinguishing effectiveness of water with a wetting agent is equal to that of pure water.

Although the use of water with wetting agents when extinguishing these solid materials has a number of advantages, they are not used very widely in Russia.

Use of wetting agents when extinguishing fires

Below are examples of extinguishing fires with wetting solutions.

When extinguishing rubber at the People's Enterprise of the Tire Factory and Furstenwalde in 1963 (several stacks measuring 4x4x2 m) it was found that a 5% wetting agent solution (neomerpipe FX) sprayed from three Arex-N-200 nozzles extinguished the fire in 1 minute 54 With. However, after extinguishing, a re-ignition occurred. It was not possible to achieve complete extinguishing using pure water and spraying jets of clean water under the same conditions.

The results of extinguishing fires in residential buildings and apartments with a wetting solution (sulfopol NP-1) are given in table 2. The conclusions from 175 large experiments in extinguishing fires with flammable substances of classes A and B are as follows:

• when extinguishing a fire in a wooden residential building, a 1% addition of a wetting agent to water allows you to reduce water consumption by 1/3 - 1/5 and shorten the duration of extinguishing;
• The greatest effect was achieved for materials such as cotton, bales of paper, wood dust and forest soil.

WETTERS (a. wetting agents; n. Benetzung agentssmittel; f. de mouillage, mouillants; i. humectadores, humectantes, mojantes) - surfactants that can be adsorbed at the interface of contact of two bodies (mediums, phases), reducing the free energy of the surface (surface tension). Wetting agents have a high hydrophilic-lipophilic balance, i.e. the ratio of the polar part of the molecule to the hydrophobic radical. When adsorbed on solid particles (minerals), wetting agents solubilize the surface, as a result of which colloidal and particles occur in aqueous particles due to the wedging effect of hydration shells.

Wetting agents are used in the processes of classification and gravitational enrichment, during wet magnetic separation, disintegration and grinding of minerals (dispersed fine particles that interfere with the implementation of these processes are removed from the surface of large particles and from the volume of the pulp). Wetting agents also promote the chemical interaction of aqueous solutions of leaching reagents (acids, soda, alkalis) in the processes of chemical beneficiation, underground leaching and hydrometallurgical ore processing. Wetting agents have found application as peptizers for drilling fluids, heavy suspensions, as well as cement and other mortars and backfill mixtures. One of the areas of application of wetting agents is to prevent the precipitation of salts, such as gypsum, iron hydroxides, and water-soluble minerals from their saturated solutions.

In relation to water-insoluble emulsions of apolar substances and reagents (for example, oil, kerosene, fatty acids, etc.), many surfactants that are wetting agents promote the dispersion of apolar substances in water and aqueous solutions. This feature is used to enhance oil recovery, for conditioning flotation reagents, photographic emulsions, dyes, and lubricants. One of the important uses of wetting agents in the mining industry is to improve the efficiency of dust suppression during water spraying: wetting agents are added to an aqueous solution in small quantities, which improves the wetting of dust particles.

Wetting agents include silicates, polyphosphates, alkali metal lignosulfonates (liquid glass, sodium fluorosilicate), and some complexing reagents (for example, sulfosuccinic acid esters). Wetting agents are also water-soluble natural and synthetic organic polymers (starches, dextrins, tannins, polymethacrylates). Animal glues, gelatins, alginates (algae extract), sulfite liquors and semi-synthetic types of ethylenediaminetetraacetyl are used as wetting agents for mineral suspensions.

Foam and wetting solutions are widely used to extinguish all types of fires. Their use makes it possible to reduce the consumption of fire extinguishing agent, reduce extinguishing time and reduce losses from fire. To obtain foam and wetting solutions, foaming agents are used, which are concentrated aqueous solutions of surfactants (surfactants) and other stabilizers. Foam was first obtained at the beginning of the last century as a result of a chemical reaction between soda and aluminum sulfate. The released carbon dioxide formed a bubble system, the stabilizer of such a foamed structure was “soap root”, and then licorice root extract - the so-called natural surfactants.

One of the most common and effective methods of fighting fires is extinguishing them using fire foam.

How does fire foam extinguish? Fire foam is air bubbles separated by partitions of water, which contains a foam stabilizer - a surfactant-based foaming agent. It is known that for a fire to occur, the following are needed: a flammable substance, an air oxidizer, the desired combination of their concentrations and ignition temperature. Combustion is a chemical process between fuel vapor and air oxidizer. To extinguish a fire, you need to isolate fuel vapors from the air oxidizer and/or reduce the temperature of the fuel below the ignition (flash) temperature. Firefighting foam provides these properties and functions.

In water-foam fire extinguishing technology, foaming agents (foam concentrates) serve as the initial component for obtaining a working solution of a foaming agent by diluting it with water to the required working concentration. The working solution of the foaming agent is supplied under pressure to various foam-generating devices (foam generators), in which a foam jet is formed due to the processes of atomization and ejection of ambient air. Aqueous working solutions of foaming agents and wetting agents are widely used when extinguishing fires using sprinklers, as well as on fire-fighting aircraft.

Wetting agents and foaming agents are divided into:

1. WA – synthetic foaming agents that do not contain fluorinated surfactants, used for extinguishing fires as wetting agents;
2. S – synthetic foaming agents that do not contain fluorinated surfactants;
3. S/AR – synthetic alcohol-resistant foam concentrates for special purposes without fluorinated surfactants for extinguishing water-soluble and water-insoluble flammable liquids;
4. AFFF – synthetic fluorine-containing film-forming foam concentrates for the purpose of extinguishing flammable liquids;
5. AFFF/AR - synthetic fluorine-containing film-forming, alcohol-resistant foaming agents for special purpose for extinguishing water-soluble and water-insoluble flammable liquids;
6. AFFF/AR-LV - synthetic fluorine-containing film-forming alcohol-resistant foaming agents of low viscosity for extinguishing water-soluble and water-insoluble flammable liquids;
7. FP – protein fluorine-containing foam concentrates intended for extinguishing flammable liquids;
8. FP/AR – protein fluorine-containing alcohol-resistant foam concentrates for the purpose of extinguishing water-soluble and water-insoluble flammable liquids;
9. FFFP - protein fluorine-containing film-forming foaming agents for special purpose for extinguishing flammable liquids;
10. FFFP/AR - protein fluorine-containing film-forming, alcohol-resistant foaming agents for special purpose for extinguishing water-soluble and water-insoluble flammable liquids.

One of the important areas of application of foaming agents is the production of wetting agents. These are solutions of surfactants in water, which, by reducing the coefficient of surface tension of water, allow it to better penetrate flammable solids and fibrous substances. Wetting agents penetrate into deep layers of materials as combustion objects, effectively cool and wet them due to a higher rate of impregnation and spreading than water. Due to the fact that wetting agents are able to saturate burning surfaces deeper, they eliminate hot spots of smoldering and smoke formation where water is less effective.

Wetting agents are classified as type WA, but general purpose foaming agents type S can be used as wetting agents.

Wetting agents are most widely used for extinguishing forest and peat fires. In those places where there is a high risk of forest and/or peat fires, in areas with arid climates or where there is a shortage of water to fight forest and peat fires - there are no large rivers, lakes or fire reservoirs - there must be reservoirs with ready wetting solutions.

For the production of wetting agents, hydrocarbon synthetic foaming agents of types WA and S are used.

Foaming agents (foam concentrates) of type S are products with a wide range of applications, used to combat fires of solid, liquid and fibrous combustible substances and materials. Suitable for both the production of fire foam and the production of wetting agents. They have high foaming ability.

Foaming agents type WA are exclusively suitable for the production of wetting agents. They have a low foaming ability, but their working solution has a high wetting ability, easily penetrates into porous materials and is especially suitable for extinguishing wood, cotton, peat, and straw.

If your occupation is related to forestry, fire control services or emergency services, you understand exactly how necessary fire extinguishing agents, wetting agents, foam concentrates, special equipment and inventory are. The lack or absence of these funds in areas of high fire risk can lead to catastrophic consequences. Therefore, it is necessary to carefully monitor the availability and timely replenishment of foaming concentrates, the serviceability of equipment, as well as the practical and theoretical training of those responsible for fire safety and fire extinguishing.

Forest fires annually destroy thousands of hectares of forest around the world; once a fire has spread over large areas, it is very difficult to stop. Therefore, it is necessary to organize and maintain a system for early detection of forest fires and prompt extinguishing of outbreaks. But if it was not possible to notice and extinguish the fire in time, then fire-fighting equipment is widely used to localize and eliminate fires - from hand-held sprayers that knock down the flames to firefighting aircraft.

In any of the above cases, the greatest extinguishing effect will be provided by the use of fire foam and wetting solutions. Therefore, it is necessary to purchase wetting agents and foaming agents for extinguishing forest fires in advance. You can buy them from our company.

Wetting agents (auxiliary substances) OP-7 and OP-10

is a light oil-like liquid or paste. The color of the wetting agent varies from light yellow to light brown. Wetting agents are nonionic surfactants (surfactants). Wetting agents are highly soluble in water, have a low odor and a slightly alkaline reaction. Wetting agents are obtained by treating mono- and dialkylphenols with ethylene oxide.

Chemical formula: O(CH 2 -CH 2 -O)nCH 2 -CH 2 -OH.
n=7-9 (for substance OP-7) and 10-12 (for substance OP-10).

Application of wetting agents OP-7 and OP-10.
They are used as wetting and emulsifying surfactants in a variety of technological processes. Wetting agents are included in TMS preparations and herbicides. They have found their application in oil production, oil refining, chemical, textile and other industries. One advantage of surfactants is that they are easily treated biologically in wastewater.

Physico-chemical parameters of wetting agents (auxiliary substances) OP-7 and OP-10 GOST 8433-81:

Indicator name	Norm for a substance
	OP-7	OP-10
Appearance	Light yellow to light brown oil-like liquid or paste
Appearance of an aqueous solution with a concentration of 10 g/l	Clear or slightly cloudy liquid	Clear liquid
Mass fraction of the main substance, %, not less	88	80
Mass fraction of water, %, no more	0,3	0,3
The indicator of the concentration of hydrogen ions (pH) of an aqueous solution with a concentration of 10 g/l	6-8	6-8
Temperature limits for the brightening of an aqueous solution, ° C substances OP-7 concentration 20 g/l substances OP-10 concentration 10 g/l	55-65 -	- 80-90
Surface tension of an aqueous solution with a concentration of 5 g/l, nm, no more	0,035	0,037

Safety requirements for wetting agents (auxiliary substances) OP-7 and OP-10 GOST 8433-81:

Hazard Class	3
Basic properties and types of hazard
Basic properties	Oil-like liquids or pastes from light yellow to light brown in color, have a slightly alkaline or slightly acidic reaction, and are highly soluble in water.
Explosion and fire hazard	Auxiliary substances OP-7 and OP-10 are fire hazardous. They ignite from an open flame when heated.
Danger to humans	Harmful if swallowed. Causes skin and eye irritation. They have an allergenic effect. Contact with skin causes contact dermatitis. If it gets into the eyes, conjunctivitis develops.
Individual protection means	Overalls, safety glasses, robe or cotton suit, rubber gloves or canvas mittens, rubberized apron, rubber boots, filter gas mask.
Necessary actions in emergency situations
General	Remove strangers. Isolate the hazardous area. Wear protective clothing. Eliminate all sources of fire and sparks. Observe fire safety measures. Provide first aid to the victims.
In case of leakage, spillage and scattering	Stop the leak if it is not dangerous. Wash off small leaks with plenty of water. Protect large leaks with an earthen berm, pump out the product into a container, and fill the remainder with plenty of water.
In case of fire	Wear protective clothing. To extinguish, use finely sprayed water, dry powders or gas compositions. Supplying ordinary foam or room water can lead to foaming of the burning liquid, overflowing the side of the container and increasing the combustion area.
Neutralization
First aid measures	Fresh air, peace. Rinse eyes and mucous membranes with plenty of running water. In case of contact with skin, rinse with plenty of water for at least 15 minutes.

Packaging, transportation and storage
Wetting agents OP-7 and OP-10 are packaged in steel barrels with a capacity of 100-300 liters and steel railway tanks.
Transportation of wetting agents is carried out mainly by rail and road transport, but transportation by other modes of transport is also possible. When transporting by rail, steel railway tanks are used. When transporting by road, standard factory packaging or special steel tanks are used.
Wetting agents OP-7 and OP-10 are stored in covered warehouses in hermetically sealed steel containers.
The guaranteed shelf life of the product is 1 year from the date of manufacture.