WO2019151898A2

WO2019151898A2 - Method for preventing fire and explosion and for solid foam extinction using a foamed silica gel and device for the implementation thereof

Info

Publication number: WO2019151898A2
Application number: PCT/RU2019/000018
Authority: WO
Inventors: Геннадий Николаевич КУПРИН; Денис Сергеевич КУПРИН
Original assignee: Общество С Ограниченной Ответственностью Нпо "Современные Пожарные Технологии"
Priority date: 2018-01-17
Filing date: 2019-01-16
Publication date: 2019-08-08
Also published as: WO2019151898A3; RU2672945C1

Abstract

The invention relates to the field of fire extinguishing techniques, and more particularly to techniques and devices for preventing fire and explosion and for extinguishing a fire, which are in the form of a fast-acting and inorganic foam based on a foamed silica gel Si0₂, and can be used for preventing fire and explosion in the incipient stage of indoor and outdoor emergencies and for extinguishing fires involving flammable materials. In order to increase the operational reliability of fire extinguishing and fire and explosion prevention agents and to improve the efficiency of fire and explosion prevention and fire extinguishing processes, in fire and explosion prevention and solid foam extinction involving the preparation of a foamed silica gel in the form of a fast-hardening foam by means of mixing a component A, in the form of an aqueous solution of a blend of an alkali metal silicate and a foam-forming surfactant, with a component B, in the form of a silica sol formation activator, and foaming the mixture of components A and B, component A is in the form of an aqueous solution of a blend of an alkali metal silicate, preferably sodium silicate, and a surfactant, preferably a synthetic hydrocarbon foaming agent, in the following proportions (in wt%): 10-70%, preferably 20-50%, alkali metal silicate; 1-15%, preferably 3-6%, foam-forming surfactant; the remainder water; and component B is in the form of a 20-60%, preferably 30-50%, aqueous solution, preferably of acetic acid, with the ratio of components A and B being between 15:1 and 6:1, preferably 10:1. In the present device, a means for mixing components A and B is configured in the form of an ejector mixer capable of ejecting component B into component A, and is disposed directly upstream of a means for foaming the mixture of extinguishant components, which is configured in the form of an ejector foam generator capable of foaming the mixture of components A and B by the ejection of atmospheric air.

Description

Method for fire and explosion prevention and solid quenching with foamed silica gel and device for its implementation

Technical field

The invention relates to fire fighting technology, and in particular to technologies and devices for fire prevention and fire extinguishing in the form of quick-hardening inorganic foam based on foamed S1O2 silica gel and can be used for fire prevention in the initial stage of emergency situations in closed rooms and in open areas and when fighting fires of combustible materials.

State of the art

It is known that water is the most widely used fire extinguisher for extinguishing fires [A.N. Baratov, E.N. Ivanov. Fire fighting at chemical and oil refining enterprises. - M.: Chemistry, 1979, p. 64-72].

To increase the fire extinguishing ability of water, organic additives are usually added to its composition, which increase the viscosity of water (thickeners) or reduce its surface tension (foaming agents) [SU 797707, A62D 1/00, 1981], or add additives of inorganic salts - chlorides, carbonates and bicarbonates of alkali metals, clay and other fine substances that increase the fire extinguishing ability of water.

Known, in particular, is a mineral-water suspension for extinguishing a fire [RU 2098158, A62D1 / 00, A62CZ / 00, 12/10/1997], which contains May in order to increase the adhesive and insulating properties of the mineral-water composition. %: 7-16 water glass, 13-72 clay and 20-80 water. The resulting suspension is used by spraying with various existing methods (using pumps, spills from airplanes or helicopters). Most Dispersion methods using explosion energy or pressure accumulators (air, powder, etc.) are effective. allow dispersing the composition to droplets with a diameter of less than 10 microns, significantly increasing the surface of interaction with the flame.

The main disadvantage of such compositions is the multicomponent, the complexity of preparation and the possibility of separation during storage, as well as the allocation of toxic combustion products during the decomposition of organic components of the composition.

Known extinguishing agent for extinguishing oil and petroleum products [RU 2263525, A62D1 / 00, 10.1 1.2005], which to increase efficiency, low cost and ease of use contains an extinguishing agent deposited on granules of refractory porous material with a diameter of 10-50 mm with a working layer thickness 1-5 mm. Extinguishing composition contains calcium bicarbonate in an amount of 0.2-0, 8 weight. o'clock, liquid glass in an amount of 0.2-0, 8 weight. hours and 0, 1-0.3 weight. including inhibitory additives.

The known composition [DE 10054686, 06/06/2002], containing more than 50% liquid glass, mainly 90-98% with a liquid glass module in the range of 1-4. The effectiveness of this composition is ensured by the ability of liquid glass to form a heat-resistant insulating film on the combustion surface, which prevents the access of oxygen to the combustion surface.

The main disadvantage of this composition is its high viscosity, in connection with which this extinguishing composition is applied to the combustion surface from aerosol containers using transport gases - nitrogen, carbon dioxide or foaming agents, as well as using other devices.

For more efficient use of liquid glass as a quenching composition, it is necessary to reduce its viscosity by introducing water into the composition. In relation to water, water glass is a thickener, and in relation to water glass, water is a thinner.

A known composition for extinguishing forest fires with a small amount of water [RU 2449825, A62D 1/00, 05/10/2012] containing water and a finely ground mixture of fusible glass at a concentration of 0.0001-10% in the form of a solution or suspension. When melted by fire, the components form glass film on the surface of a burning object and impede the access of oxygen.

Known aqueous solution for extinguishing fires [RU 2275951, A62D 1/00, 05/10/2006], which in order to ensure the necessary level of viscosity and achieve a significant reduction in temperature in the combustion zone, high temperature resistance and insulating ability of the composition due to evaporation of free water and thermal foaming liquid glass, contains water in an amount of 50-95 may. % and as a thickening additive liquid glass with a module of 2, 5-3, 2 in the amount of 5-50 may. %

Additionally, this composition may contain a high molecular weight surfactant in the form of a mixture of polyvinyl alcohol-toluene-water with a surface tension of less than 30 mN / m at the rate of 0.001-0.1 kg of surfactant per cubic meter of water in solution.

The presence of surfactants in this composition of the solution improves its dispersion when spraying and fixing on the combustion surface. After quenching with the proposed composition, the surface of the objects of combustion as a result of thermal foaming or, in their physical essence, boiling as a result of intense heating of the sprayed solution layer is covered with a layer of solid inorganic foam with a thickness of 2, 5-5, 5 cm, and this layer, acting as a kind of filter, provides a smaller residual smoke from the combustion surface.

As indicated in the description of RU 2275951, extinguishing a fire with this composition is carried out according to the following mechanism: When a jet of liquid glass approaches the combustion surface, the solution heats up under the influence of high temperature and its viscosity decreases, which contributes to a better spreading of the solution on the combustion surface.

When water evaporates from a solution on the combustion surface, the concentration of water glass increases, its viscosity increases significantly, and when water completely evaporates from the solution on the combustion surface, a liquid glass film with the property of continuity remains.

An increase in the wettability of the combustion surface with a solution and an increase in the degree of dispersion of the jet are achieved by introducing into the composition of a high molecular weight surfactant with a surface tension of less than 30-10 ³ N / m, for example, based on polyvinyl alcohol, toluene and water in an amount of 0.001-0.1 kg / m ^{3 of} water in solution.

A liquid glass film formed after evaporation of free water on the combustion surface at a temperature of 120-200 ° C loses molecular water and acquires a solid state. In the temperature range 200-400 ° C, chemically bound water begins to be removed from the solid liquid glass, under the influence of which the liquid glass crust acquires a pyroplastic state, and the water vapor released, due to a sharp increase in its volume, foams this crust and its volume increases by 10-50 time. The density of the foam layer formed on the combustion surface is 30-50 kg / m ³ and this layer blocks the access of air oxygen to the combustion surface.

The resulting foam layer is not subject to burning, as it is an inorganic substance in its composition - anhydrous alkali metal silicate, has a low coefficient of thermal conductivity (0.03-0.036 W / m -K) and prevents the quenched surface from heating to a fire temperature due to a sharp decrease in intensity exposure to heat flux generated by the emission of flame and convective heat from flue gases.

The disadvantages of RU 2275951 are the practical impossibility of uniformly spraying and the practical impossibility of providing controlled thermal foaming of the liquid glass solution on the surfaces of burning materials that are almost always uneven and changing during the burning process and, accordingly, the impossibility of obtaining a given thickness of a solid foam of a certain structure, as well as the need for high temperature for thermal foaming, namely the need for a temperature of 120-200 ° C for the evaporation of a mole acous- water and tverdoobraznogo acquisition status and the need for a temperature of 200-400 ° C to remove tverdoobraznogo waterglass chemically bound water, under the action of the crust which becomes waterglass pyroplastic state, and the subsequent intensive discharge of water vapor (boiling) for foaming of the crust. It is known to use sprayed water as a fire extinguishing agent, however, sprayed water has a relatively low fire extinguishing efficiency, and its generating devices require connection to pressurized water pipes.

It is known to use air-mechanical foam of low and medium multiplicity, which has increased fire extinguishing efficiency compared to sprayed water, however, most of the known water-foam generators and fire extinguishers provide a liquid air-mechanical foam based on an aqueous solution of a foaming agent and air or gas, which quickly settles and does not hold on vertical and inclined surfaces, which significantly reduces efficiency and increases fire fighting time.

A fire extinguisher is known that contains a container with a fire extinguishing liquid, a system for displacing a liquid from a container, a locking and starting device, a liquid atomizer with a centrifugal flow swirler and an outlet nozzle, and a pipeline connecting the output of the locking and starting device with a liquid atomizer, in which, to increase the efficiency of extinguishing ignition zones, first of all, classes “A” and “B” by generating a high-speed atomized stream of extinguishing liquid with a given spray angle, the output nozzle of the liquid atomizer a profiled channel including a section narrowing in the direction of the fluid flow, wherein the centrifugal swirl is made in the form of a hollow insert with at least one tangentially directed inlet channel formed in the side wall of the insert and an inlet axial channel, the insert cavity being in communication with the inlet of the profiled nozzle [RU 43465 A62C13 / 62, A62C31 / 02, publ. January 27, 2005].

A fire extinguisher is known that contains a container filled with a liquid fire extinguishing agent, a source of displacing gas, a shut-off and starting device, a liquid spray connected through a pipe to the exit of the locking and starting device, while the liquid spray is configured to generate a directed finely dispersed jet of fire-extinguishing substance, in which, to provide the ability to effectively extinguish fires of Class A and B fires and electrical equipment under high voltage, and long-term storage and operation of a fire extinguisher at low temperatures, as a liquid fire extinguishing agent, a mixture of an aqueous salt solution selected from the following series of substances is used: diammonium phosphate, magnesium chloride, calcium chloride, lithium chloride, and a foaming agent, and the salt content in the extinguishing agent is at least 10 wt. .%, the content of the film-forming foaming agent in the extinguishing agent is at least 5 wt.%. In this case, compressed gas was used as the source of displacing gas, filling the gas cavity in the container above the surface of the liquid extinguishing agent, and the liquid atomizer is equipped with a jet-centrifugal liquid flow swirl and an outlet nozzle and is made with a profiled channel including an inlet section of a cylindrical shape and an outlet section in the shape of a conical diffuser, while the inlet of the outlet section is associated with the outlet of the cylindrical section [RU 82562 A62C13 / 62, A62C31 / 02, publ. 05/10/2009].

Known portable fire extinguisher containing a reservoir with a fire extinguishing agent, a launcher head housing mounted on a reservoir with a fire extinguishing agent, a spring-loaded rod with a conical protrusion located in a longitudinal channel made in the launcher head housing, which has a first radial hole mounted on the launcher head housing for compressed gas with a sealing membrane facing the conical protrusion of the rod, siphon tube, outlet fitting and means for moving the rod, elastic gasket installed on the rod, while the longitudinal channel has two cavities separated from each other by a sealing element mounted on the rod, the first cavity communicates with the outlet of the compressed gas cylinder and through the first radial hole with the cavity of the reservoir with a fire extinguishing substance, the second cavity communicates with a second radial hole with a siphon tube, and with a third radial hole with an outlet fitting, in which, to prevent leakage of extinguishing agent during storage and transportation, while maintaining the possibility of a short termination of its operation, a cylindrical spring and a washer are installed in the second cavity on the rod, an elastic gasket is located on the lower surface of the washer, a cylindrical spring is located between the washer and the upper wall of the second cavity, and the length of the cylindrical spring in the axial direction in the free state exceeds the distance from the washer to the upper wall of the second cavity [RU 8896 A62C13 / 00, publ. 01/16/1999].

Known devices for producing hardening foam from a composition of low molecular weight and high molecular weight substances, providing an increase in foam generation productivity, continuous operation without stops for recharging containers with working solutions, which contains a cylindrical body, nozzles for supplying liquid and gas and a gas-liquid flow diffuser located coaxially to the body, while the nozzles for supplying an aqueous solution of a surfactant and a urea-formaldehyde resin are offset relative to the axis the housing and the mixer at a distance of 5-15% of the inner diameter of the pipe [RU 2226123 B01 F3 / 04, B01 F5 / 04, publ. 03/27/2004].

The device according to RU 2226123 can be used to create protective foam screens to prevent the evaporation of oil and oil products during emergency spills and in the technology of processing polymers into porous or cellular products for various purposes, but due to the combustibility of the obtained solid foam, it is not applicable in the field of fire fighting.

A fire extinguisher is known, having at least one container with a fire extinguishing means, is configured to withdraw this means if a real or potential fire is identified. The fire extinguishing agent is a stable aqueous suspension of finely dispersed expanded vermiculite (a natural mineral with the chemical formula (Mg, Fe, A1) s (A1, Si) ₄ Oio (OH) ₂ 4H ₂ 0). The method of extinguishing a fire is carried out by supplying this means of extinguishing a fire to a flame, zones adjacent to it, as well as zones of high risk of fire spread. The fire extinguisher used can be made by at least partially filling a container adapted to remove the fire extinguishing agent. The tool has an improved limiting effect and the formation of an insulating barrier due to the formation of a layer on the surface of the barrier with respect to oxygen and heat, can be used to extinguish fire on humans and animals. It is desirable that the quantity vermiculite was 3-40 wt.%, more preferably 10-30 wt.%, and particularly preferably 15-25 wt.%, for example, about 20 wt.%.

Preferred is very fine vermiculite with a particle size in the range from nanometers to 1000 microns, and it is desirable that this size does not exceed 300 microns [RU 2635613 A62D1 / 00, A62CZ / 00, C09K21 / 02 Publ. 14.1 1.2017].

The disadvantage of RU 2635613 is the possibility of using a fire extinguishing agent only in the form of an aqueous finely divided suspension and the inability to form foam on its basis.

Chemical foam extinguishers are known that generate chemical foam resulting from the sharp foaming of an alkaline solution (usually an aqueous solution of soda) by adding acid (usually sulfuric or hydrochloric) to it.

Known fire extinguisher for the formation and supply of chemical foam, containing a housing filled with an alkaline solution, a spray located in the upper part of the housing, a lid and a bottle of acid, closed with a plug with a rod, while the cylinder is equipped with a float in which, for uniform distribution of acid charge in the fire extinguisher body, the float is made in the form of an annular chamber and is mounted concentrically to the cylinder body in its lower part [RU 26191 A62C13 / 04, publ. November 20, 2002].

Known chemical foam fire extinguisher containing a vessel with a lid filled with an alkaline solution, a spray located in the upper part of the vessel, an acid cylinder, the bottom of which is made in the form of a membrane, a drive rod and a sampling tube installed in the vessel, one end of which is connected to the spray, and the other is facing the bottom of the vessel, in which, to increase the operational properties and speed of response, the drive rod is equipped with a piston located in the cavity of the container, and a through hole is made in the wall of the container, located th above the piston part [RU 26192 A62S13 / 04, publ. November 20, 2002].

A chemical air-foam fire extinguisher is known, containing a steel casing filled with 9 l of an alkaline aqueous solution in the form of a mixture of sodium bicarbonate NaHCCh and licorice extract, and a polyethylene container filled with an acid mixture in the form of sulfuric acid H2SO4 and iron sulfide FeS0 ₄ , which increases the volume and strength emerging foam, at the same time, to increase the efficiency of fire protection by increasing speed and reliability of operation, the polyethylene container is rigidly connected to the valve seat fixed in the lower part of the glass, rigidly connected to the lid of the steel casing, to the upper part of which is attached a handle for operating in fire extinguisher operation mode and in the upper part of the housing there is an exhaust pipe with a foam generator. The glass is installed inside the housing axisymmetrically to him and the polyethylene container, and the valve is connected to a rod placed axisymmetrically in the glass and spring-loaded. At least three openings are made in the lower part of the glass above the valve, which provide for the connection of the alkaline and acid parts of the fire extinguisher, and on the cover of the fire extinguisher’s body there is a locking and starting device [RU 2427401 A62C13 / 04, publ. 08/27/2011].

A common drawback of known chemical foam fire extinguishers is the insufficient fire extinguishing efficiency, usually caused by a small amount of generated chemical foam, determined by the stoichiometric ratio of the reagents, as well as the possibility of only one use during the course of the reaction with the impossibility of interrupting it to fully produce the components and the impossibility of repeatedly switching the fire extinguisher at the same charge of the fire extinguisher with the components of the fire extinguisher nature.

A device is known for creating a fluid hardening foam based on water, cement and a blowing agent for preventing and extinguishing a fire in a coal mine, comprising a main aggregate machine, an automatically replenished liquid storage tank, a solution mixing system, an injection gun and a corresponding connecting pipe system, wherein a valve, a three-way valve, a pressure sensor and a flow meter are appropriately located on the pipeline; and the main aggregate machine comprises a two-tier carcass structure, wherein the lower tier of the carcass is equipped with an air compressor, an intelligent control panel and a screw pump, and the upper tier of the carcass is equipped with a foaming pipe and a mixing pipe. The flowable hardening foam formed by the device has the advantage of well-distributed fine bubbles, high foaming coefficient and good foam stability characteristics; and the device has ideal system functions, unhindered circulation of the solution, is easy to operate and reliable to use, can adapt well to the difficult conditions of a coal mine and quickly and continuously create a fluid hardening foam, and is used in coal mines to stop leaks, isolate oxygen and fire prevention and suppression, and thus effectively ensures the safety and effectiveness of fire prevention and suppression in coal mines [RU 2620335 A62C5 / 02 Publ. 05.24.2017].

Known methods and devices for foaming non-combustible suspensions for fire fighting purposes.

A device for foaming suspensions when fighting underground fires is known, which contains an ejector, a sleeve with a combined channel, a dispersant, a mixing chamber. In the ejector, the suspension is divided into two parts. The main stream goes through the sleeve. It is crushed on a dispersant. Additional flow passes through the annular gap. Then it is deflected by a conical chipper onto the foam mesh and flows down. Inert gas passes into the cavity of the gas jacket and forms a high-pressure foam. The main stream is mixed with foam. A foamed suspension forms in the mixing chamber. Increases the efficiency of the preparation of suspensions in short wells due to the intensification of the foaming process [RU 2133829, E21 F5 / 00, A62C5 / 02, B01 F5 / 06 Publ. July 27, 1999].

A complex system is known for creating a curtain of foamed slurry containing a turbulent device for foaming suspensions, a fire-irrigation pipe of a mine, nozzles for supplying a solution of a foaming agent and compressed gas, a mixing chamber, a pipe channel with a pricing device installed in it and sources for supplying components for generating foam, characterized the fact that it is equipped with a stabilizer structure of the foamed suspension mounted on the output flange of the foaming device in the adapter before exiting transport foam, at the end of which there is a perforated peak for its implementation in inaccessible place, while to stabilize the structure of the foamed pulp, it is equipped with an additional nozzle for introducing a filler solution into the device, for example, fly ash, which is prepared and fed to the foaming device by means of a slurry submersible pump from a mine carriage at the place of work, and into the water pipeline from fire-irrigation pipeline built-in foam mixer with an adjustable intake tap of the foaming agent with the simultaneous introduction of a foam flow structure stabilizer into the pressure hose, made in the form of a solution of bentonite colloidal clay, which is also prepared in the second half of the trolley using a slurry submersible pump. The chamber for mixing the components of the mixture in the foaming device of the suspension is made in the form of a diffuser along the foaming suspension in the zone in front of the screw stabilizer, and the flow rate of the amount of the liquid phase dosed in the system (bentonite clay, foaming agent, water and liquid filler) is regulated by control valves in each pipeline and time work slurry submersible pump [RU 33021, A62C5 / 02, Publ. 10/10/2003].

A complex system for creating a curtain in a mine from a foamed combined suspension is known, which contains nozzles for supplying a solution of a foaming agent and air, a mixing chamber and a pipe channel with a foaming device installed in the form of turbulent plates, characterized in that it is fixed to the foaming device on the side of the ash supply pipe additional adapter with a diffuser mixing chamber connected to the foam generator housing, on which the phlegmati supply pipe is installed an atom — for example, the liquid phase of Freon 114B2 mixed with gaseous nitrogen and a nozzle for supplying nitrogen gas, and at the outlet of the foaming device there is a confuser adapter for controlling the pressure of stabilizing the structure of the foam flow, made with screw blades built into the pipeline, which is connected directly to the connecting bend to the casing pipe wells drilled from the surface into the zone of the underground fire [RU 50839, A62C5 / 02, Publ. January 27, 2006]. A disadvantage of the known devices for foaming suspensions and the use of foamed suspensions for fire fighting is the complexity and cumbersomeness, the inability to use them to extinguish open fires and explosion prevention in open areas of large areas, that is, their low fire extinguishing efficiency.

Known aqueous solution for extinguishing fires [RU 2275951, A62D1 / 00, 05/10/2006], which in order to ensure the necessary level of viscosity and achieve a significant reduction in temperature in the combustion zone, high temperature resistance and insulating ability of the composition due to evaporation of free water and thermal foaming liquid glass, contains water in an amount of 50-95 may. % and as a thickening additive liquid glass with a module of 2, 5-3, 2 in the amount of 5-50 may. %

Additionally, this composition may contain a high molecular weight surfactant in the form of a mixture of polyvinyl alcohol - toluene - water with a surface tension of less than 30 mN / m at the rate of 0.001-0.1 kg of surfactant per cubic meter of water in solution.

The presence of surfactants in this composition of the solution improves its dispersion when spraying and fixing on the combustion surface. After quenching with the proposed composition, the surface of the objects of combustion as a result of thermal foaming or, in their physical essence, boiling as a result of intense heating of the sprayed layer of the solution is covered with a layer of solid inorganic foam with a thickness of 2.5-5.5 cm, and this layer, acting as a kind of filter, provides a smaller residual smoke from the combustion surface.

As indicated in the description of RU 2275951, the fire extinguishing by this composition is carried out according to the following mechanism: When a jet of liquid glass approaches the combustion surface, the solution heats up under the influence of high temperature and its viscosity decreases, which contributes to a better spreading of the solution on the combustion surface. When water evaporates from a solution on the combustion surface, the concentration of water glass increases, its viscosity increases significantly, and when water completely evaporates from the solution on the combustion surface, a liquid glass film with the property of continuity remains. An increase in the wettability of the combustion surface with a solution and an increase in the degree of dispersion of the jet are achieved by introducing into the composition of a high molecular weight surfactant with a surface tension of less than ZOI ³ N / m, for example, based on polyvinyl alcohol, toluene and water in an amount of 0.001-0, 1 kg / m ^{3 of} water in solution.

A liquid glass film formed after evaporation of free water on the burning surface at a temperature of 120-200 ° C loses molecular water and acquires a solid state. In the temperature range 200-400 ° C, chemically bound water begins to be removed from the solid liquid glass, under the influence of which the liquid glass crust acquires a pyroplastic state, and the water vapor released, due to a sharp increase in its volume, foams this crust and its volume increases by 10-50 time. The density of the silicate foam layer formed on the combustion surface is 30-50 kg / m ³ and this layer blocks the access of air oxygen to the combustion surface.

A layer of solid silicate foam formed in this way is not susceptible to combustion, as it is an inorganic substance in its composition - anhydrous alkali metal silicate, has a low thermal conductivity (0.03-0.036 W / m-K) and prevents the quenched surface from heating to ignition temperature due to a sharp decrease in the intensity of the heat flux generated by the emission of flame and convective heat of flue gases.

The disadvantages of RU 2275951 are the practical impossibility of uniformly spraying and controlled thermal foaming of a liquid glass solution on practically always uneven and burning surfaces of burning materials and, accordingly, the inability to obtain a predetermined thickness of a “glass” foam of a certain structure, as well as the need for a high temperature for thermal foaming, namely the need for a temperature of 120-200 ° C for the evaporation of molecular water and the acquisition of solid figurative state and the need for a temperature of 200-400 ° C to remove chemically bound water from solid liquid glass, under the action of which the liquid glass crust acquires pyroplastic condition, and subsequent intensive release of water vapor (boiling) for foaming this crust and its transformation into a solid silicate foam.

The porous xerogel S1O2 is known [RU 2530048 C01 B 33/16, publ. 10.10.2014 Application PCT EP 2010/067821 20101 119, publication PCT WO 2011/061289 20110526] which contains pores that are larger than 50 nm but less than 1000 nm, in particular less than 500 nm, in particular less than 300 nm, in particular - less than 100 nm, has a density of less than 400 kg / m ³ , in particular less than 290 kg / m ³ , in particular less than 200 kg / m ³ , contains a fraction of carbon that is less than 10%, in particular less than 5% , and has a thermal conductivity at 800 ° C less than 0,060 W / m-K, at 400 ° C - less than 0,040 W / m-K, at 200 ° C - less than 0,030 W / m-K, has a modulus of elasticity equal to at least 5 MPa, at temperatures up to 560 ° С (in atmo Feret containing oxygen) has long thermostability, is a monolithic molded product granulate or powder.

This xerogel S1O2 according to RU 2530048 with a characteristic pore size of less than 1 micrometer is obtained by a sol-gel process with subcritical gel drying using temporary pore fillers or solid skeletal supports (for example, consisting of carbon or organic substances), which are removed at the end of the preparation process through thermal oxidation. Ancillary organic particles, or macromolecules, or carbon particles contained in an inorganic gel, inhibit the collapse of the inorganic network during the subcritical drying process. Subsequently, these pore fillers or solid skeletal supports are removed to the maximum extent during heat treatment at temperatures above 300 ° C due to oxidation. The result is xerogel S1O2 (with a mass fraction of fibers of less than 5 wt.%) With a porosity of more than 80%, with an unbound or only weakly chemically bonded carbon silicate skeleton of less than 10% and a pore size of less than 1 micrometer.

Xerogel S1O2 according to RU 2530048 is used as a non-combustible or non-flammable, transparent or translucent or opaque heat-insulating material, as a supporting heat-insulating material, a catalyst support, a filter, an absorber, non-combustible or non-flammable, transparent, translucent or non-transparent light building material, dielectric for electronic parts, as a system for controlled or rapid release of drugs, as a coating for use in thermal diffusion processes, as a mold, as a carrier for sensor molecules in sensor technology, for sound insulation, for humidity control or as a base material for composite materials.

Known composition for creating foamed aerosol heat-resistant foam based on sodium silicate [EP 01 10328], containing two separate solutions, one of which, solution "A", is based on an aqueous solution of sodium silicate (50-97%) and propellant (3-50%), and the other - solution "B", which is a hardener.

According to EP 0110328, various chemical additives in the form of ammonium compounds, borates, synthetic rubbers and various organic and inorganic compounds that increase the mechanical properties of foams and dispersions are added to solution “A” (the main solution), but these compounds must be compatible, i.e. . chemical reactions between them are not supposed. In order to increase the multiplicity of the foam, surfactant additives can be added to the “A” solution (to the alkali metal silicates solution).

According to EP 0110328, organic and inorganic compounds having gelling properties, preferably carboxylic acid esters, for example triaacetate glycerol, which, having high viscosity properties, act as thickeners, increasing the rheological properties of the foams formed upon mixing, are used as the “B” (hardener) solution according to EP 0110328.

Both solutions must be pressurized in separate separation vessels, moreover solution “B” (hardener) is under greater pressure than solution “A” (stock solution).

Separating containers according to EP 0110328 are used in order to avoid the curing of the hardener. To prevent precipitation of the hardener, emulsifiers are also introduced into the solutions, and stabilizing components are introduced into the solution “B” (hardener), which form microcapsules from salts of polyvalent cations, preferably Zn, Mg, and Ca. The formation of gas bubble inclusions (foaming) according to EP 01 10328 occurs under the action of the release of liquefied propylene while compensating for the pressure difference with the atmosphere,

It is proposed to use EP 01 10328 foams formed on the basis of alkali metal silicates and having stability up to 300 ° as thermal insulating foams, as a heat insulator in construction industry.

A common disadvantage of the known silicates of alkali and alkaline earth metals, foams and non-ceramic materials based on them is their relatively low thermal stability, insufficient for their use as a fire extinguishing agent in fire and explosion prevention, since it is known that the ignition temperature for most solid materials is 300 ° C, temperature the flame in a burning cigarette is 700-800 ° C, in a match the flame temperature is 750-850 ° C, the ignition temperature of wood is 300 ° C, and the burning temperature of wood is 800-1000 ° C.

The closest in technical essence and technical result achieved (prototype in terms of the method) is foamed silica gel developed earlier by the authors and patented by the applicant, the use of foamed silica gel as a fire extinguishing agent, in case of fire prevention and as an insulating and filling material in construction and in other industries industry. [RU 2590379 S01VZZ / 16, publ. 07/10/2016 (prototype)].

Foamed silica gel S1O2 according to RU 2590379 was obtained by air-mechanical foaming on known foam generators of a mixture of alkali metal silicate, mainly sodium silicate and a foaming surfactant, mainly synthetic hydrocarbon foaming agent, with a pH from 10.9 to 11, 5, in a ratio of May. %, 10-70%, mainly 20-50% silica, 1-15%, mainly 6% foaming surfactant, 15-89% water, and an aqueous solution of silica ash formation activator from alkali metal silicate, for example, 0, 1 to 6%, preferably 0.7 to 3.5% aqueous solution of acetic acid, hydrochloric acid or ammonium chloride with a pH of from 3 to 8, with a mass ratio of solutions from 100: 1 to 28: 1, mainly 35: 1.

The advantage of foamed silica gel according to RU 2590379 is the almost instantaneous reaction of the components after they come in contact and a set of mechanical strength of the foamed gel in terms of dynamic viscosity from 20 MPa-s to 100 Pa s in the time range of 2 seconds, but this makes it practically impossible to use all known foam generators and devices for the formation of foam of low and medium multiplicity due to the hardening of the foamed silica gel inside the foam generators and devices with the rapid termination of their normal function nirovaniya.

A significant drawback of the technology for generating foamed silica gel according to RU 2590379 was that it could be obtained on known foam generators by air-mechanical foaming of a mixture of diluted components, namely the use of mainly 1 to 3.5% aqueous solution of acetic acid as an activator of silica ash formation , with a predominant mass ratio of a solution of sodium silicate with a foaming surfactant and a solution of acetic acid 35: 1.

As a result of the use of low-concentrated components, the foamed silica gel obtained according to RU 2590379 using known foam generators was obtained with an insufficient amount of silica gel and a large amount of water. When using more concentrated components according to RU 2590379, solid foam was formed in the pipeline for supplying the mixture of components to the foam generator and directly in the foam generator itself, which made it impossible to use it normally.

The closest in technical essence and the technical result achieved (the prototype in terms of the device) is a chemical foam fire extinguisher containing a container filled with liquid fire extinguishing agent, a source of displacing gas, a shut-off and start device, a liquid atomizer connected through a pipeline to the exit of the shut-off and start device, wherein the liquid atomizer is configured to generate a directional fine spray extinguishing agent, in which, to generate a finely dispersed stream of extinguishing liquid, with the help of which effective extinguishing of fire centers of classes A and B is carried out, as well as electrical equipment that is under high voltage and maintaining fire extinguishing efficiency during prolonged storage and at low temperatures, as a liquid extinguishing substances, a mixture of an aqueous solution of a salt selected from the following series of substances was used: diammonium phosphate, magnesium chloride, calcium chloride, lithium chloride, and film-like present blowing agent, wherein the salt content in the extinguishing agent is not less than 10 wt.%, the content of foaming agent in the film-forming fire extinguishing agent is not less than 5 wt.%. The result is an increase in the efficiency of the fire extinguisher of a fire extinguisher by expanding technical capabilities, increasing the operating life, ensuring a stable mode of operation with the exception of the need for turning and self-operation during operation [RU 2278713 A62C13 / 04, publ. 06/27/2006 (prototype)].

As a source of displacing gas, RU 2278713 uses compressed gas filling a gas cavity in a container above the surface of a liquid extinguishing agent, the liquid atomizer is equipped with a jet-centrifugal fluid flow swirl and an outlet nozzle and is made with a profiled channel that includes an inlet section of a cylindrical shape and an outlet section in in the form of a conical diffuser, wherein the inlet of the outlet section is associated with the outlet of the cylindrical section.

When using RU 2278713, a directed finely dispersed jet of fire-extinguishing liquid is generated, which, as shown above, has lower fire extinguishing efficiency compared to air-mechanical foam with low and medium multiplicity.

Chemical fire extinguishers with the possibility of obtaining solid non-combustible foam and the possibility of solid-state extinguishing and / or fire and explosion prevention in the scope of the search were not identified.

A common disadvantage of the known water-based fire extinguishing devices and chemical fire extinguishers is that in the known devices the extinguishing agent is mainly formed inside the device body and / or in the supply lines of the extinguishing agent to the spraying and foaming means, which makes them unsuitable for use with quick-hardening silica foams due to the rapid formation of solid foam inside the devices and in the supply lines of the mixture of extinguishing agent to the spraying means, because it immediately stopped their normal functioning.

Solved problem and technical result

The objective of the invention is to eliminate the disadvantages of known analogues and prototypes.

The technical result achieved by using the invention is to increase the reliability of the fire extinguishing and fire prevention means and the efficiency of the processes of fire prevention and extinguishing.

SUMMARY OF THE INVENTION

The problem is solved and the required technical result is achieved by the fact that during the implementation of the method of fire prevention and solid extinguishing, which includes the preparation of foamed silica gel in the form of quick-hardening foam by mixing component A in the form of an aqueous solution of a mixture of alkali metal silicate and a foaming surfactant with component B in as an activator of silica ash formation and foaming of a mixture of components A and B,

according to the invention, as component A, an aqueous solution of a mixture of an alkali metal silicate, preferably sodium silicate, and a foaming surfactant, mainly a synthetic hydrocarbon blowing agent, is used, in a ratio of May. %, 10-70%, mainly 20-50% alkali metal silicate, 1-15%, mainly 3-6% foaming surfactant, the rest is water, and

as component B use 20-60%, mainly from 30-50% aqueous solution of predominantly acetic acid,

and components A and B are used with a volume ratio of 15: 1 to 6: 1, mainly 10: 1. Components A and B are mixed immediately before foaming by means of an ejector mixer configured to eject component B into the flow of component A supplied under the pressure of compressed air in the container with component A, and foaming the mixture of components A and B is performed immediately after mixing components A and B by means of an ejector foam generator, configured to eject atmospheric air into a mixture of components A and B.

When mixing components A and B, component A and then component B are first fed into the ejector mixer, and when components A and B are finished mixing, the feeding of component B to the ejector mixer is first stopped, and then component A is stopped feeding into the ejector mixer.

Mixing components A and B and foaming the mixture of components A and B is carried out to obtain a foamed silica gel with a set of its hardness for 1 second to 2 minutes and a change in its volume in the solidified state of not more than 10% for 24 hours,

to obtain a solid ceramic foam material based on a foamed silica gel having thermal stability when exposed to a temperature of 1000 ° C for at least 60 minutes, which.

contains May. %, 13-65%, mainly 20-50% silica, 1-15%, mainly 6% foaming surfactant, water - the rest;

has a bulk density of 0.1 -0.8 g / cm ³ ;

has a volumetric stability of at least 22 hours with a change in volume of not more than 10%,

and in a dehydrated state

has a bulk density of 0.05-0.1 g / cm ^{3 and}

retains at least 95% of the volume when heated to a temperature of 1000 ° C for at least 40 minutes;

has a micro- and macroporous structure with a specific surface area of at least 20 m ² / g;

has a plastic gel structure with a multiplicity of 2 to 20;

has a hardness in terms of viscosity over YuOPa s, has a white or yellowish white color.

The problem is solved and the required technical result is also achieved by the fact that the device for explosion and fire extinguishing and solid extinguishing, containing containers with the components of the extinguishing agent, piping components of the extinguishing agent, a means of mixing the components of the extinguishing agent and a means of foaming the mixture of components of the extinguishing agent, according to the invention with the possibility of implementing the method, namely with the possibility of obtaining as a fire extinguishing agent foamed silica gel in the form of quick-hardening foam, obtained by mixing and foaming a mixture of component A in the form of an aqueous solution of a mixture of alkali metal silicate, mainly sodium silicate, and a foaming surfactant, mainly synthetic hydrocarbon foaming agent, in the ratio, May. %, 10-70%, mainly 20-50% of alkali metal silicate, 1-15%, mainly 3-6% of a foaming surfactant, the rest is water,

and component B in the form of 20-60%, mainly from 30-50% aqueous solution of silica ash activating agent, mainly acetic acid,

with a volume ratio of components A and B from 15: 1 to 6: 1, mainly 10: 1.

The means for mixing the components A and B of the extinguishing agent is made in the form of an ejector mixer with the possibility of ejecting the component B into the component A and placed immediately before the means for foaming the mixture of the components of the extinguishing agent.

The foaming agent of the extinguishing agent is made in the form of an ejector foam generator with the possibility of foaming a mixture of components A and B with ejected atmospheric air.

The device comprises a locking and starting mechanism and a switchgear configured to start using the sequential supply device to the means for mixing the components of the extinguishing agent first, component A and then component B, and at the end of the use of the sequential stop device mixing the components of the extinguishing agent, first component B and then component A,

with the possibility of supplying component A to the means for mixing the components of the extinguishing agent from the container of component A under the influence of compressed air in the container with component A.

The container of component A is equipped with a nipple for injecting compressed air into the container of component A and a manometer to control the pressure of compressed air in the container of component A, and container 8 with component B is made in the form of a satchel with the possibility of carrying it over the operator’s shoulders.

The device can be made placed on a hand truck with the possibility of its mobile movement.

Brief Description of the Drawings

The invention is illustrated by drawings, images of a device for explosive fire prevention and solid foam quenching with foamed silica gel in general, an ejector mixer and an ejector foam generator, as well as examples of the use of the device and the implementation of the method of fire prevention and solid foam quenching with foamed silica gel.

In FIG. 1 shows a device for fire and explosion prevention and solid quenching with foamed silica gel.

In FIG. 2 is a drawing of a device for fire prevention and solid-state extinguishing with foamed silica gel, which shows: capacity 1 with component A in the form of a cylinder with the possibility of pumping compressed air into it; locking trigger 2; a pressure gauge 3 on the capacitance of component A to control the pressure of compressed air inside the container of component A; component A feed line; shutter (gun) 5 on / off the supply of components A and B, respectively, in the piping of components A and B; an ejector mixer 6 for mixing components A and B; an ejector foam generator 7 for foaming a mixture of components A and B to obtain a quick-hardening silica gel foam from a mixture of components A and B; capacity 8 with component B, made in the form of a satchel with the ability to carry over the shoulders of the operator; component supply pipe 9; Component B supply valve 10; trolley 11 with wheels 12; lid 13 of the container with component B; air valve 14 on container 8 with component B; handle 15 of the trolley 1 1; openings 16 on the ejector foam generator for ejecting atmospheric air into the stream of a mixture of components A and B; siphon tube 18 for supplying component A to the pipe of component A under the action of compressed air pressure injected into the container of component A.

In FIG. 3 is a cross section of an ejector mixer of components A and B, which shows the housing of an ejector mixer of components A and B with a diffuser 19 located inside it, a nozzle nozzle 20 for component A; hole 21 for ejection of component B and a mixing chamber 22 of the ejector mixer, in which component A and B. are mixed

The ejector mixer is assembled / disassembled by means of the threaded connections shown in the drawing with the possibility of threaded connection with the ejector foam generator of quick-hardening foam.

The prefabricated / collapsible design of the ejector mixer on threaded connections provides the possibility of its quick assembly / disassembly and cleaning in case hardened foam of foamed silica gel appears in it.

In FIG. 4 shows a cross section of an ejector foam generator 23 of quick-hardening foam with openings 16 for ejecting atmospheric air into a mixture of components A and B to obtain a quick-hardening foam of foamed silica gel.

In FIG. Figure 5 shows the beginning of the extinguishing of the model fire 1A using a device for explosion and fire prevention and solid-state extinguishing with foamed silica gel.

In FIG. Figure 6 shows the end of the extinguishing of the model fire 1A using a device for explosion and fire prevention and solid-state extinguishing with foamed silica gel.

In FIG. 7 shows a view of a model fire site 1A immediately after solid-state fire extinguishing by foamed silica by means of the proposed device for explosive fire prevention and solid-state fire-extinguishing by foamed silica gel of solid-state fire extinguishing and fire and fire prevention by foamed silica gel.

The implementation of the invention

The chemical process for the production of foamed silica gel and ceramic foam material based on dehydrated foamed gel silica includes a step of forming a silica sol and a foaming step of a silica sol to form a foamed silica gel and chemically releasing water, as well as a step of dehydrating the foamed silica gel to obtain a solid foam ceramic material based on foamed silica gel.

The formation of a silica sol occurs as a result of mixing and mutual homogenization of a mixture of an aqueous solution of an alkali metal silicate, mainly sodium silicate, with a foaming surfactant, mainly a synthetic hydrocarbon foaming agent, (component A), and a silica ash activating agent (component B), mainly in the form an aqueous solution of predominantly acetic acid or an aqueous solution of a salt with an acidic pH.

The transition of alkali metal silicate, mainly sodium silicate, to silica is caused by a chemical reaction of hydrolysis of sodium silicate in an aqueous medium in the presence of an ash activating agent with the formation of silicic acid and subsequent condensation of silicic acid, which contributes to the nucleation of the dispersed phase of the silica sol and the release of chemically bound water.

The influence of the ash activating activator on the polymerization of the formed silica monomers and the limitation of this stage of the process from further gelation is determined by the size of the hydrodynamic radius of the nanoparticles in the range up to 50 nm, since it is known that an increase in the concentration and size of the dispersed phase leads to the appearance of coagulation contacts between particles and the beginning of structuring.

As the studies of the authors showed, as an activator of ash formation of silica from alkali metal silicate (component B) it is advisable to use acidic solutions with a pH of from 0.5 to 5, for example, an aqueous solution from 20 to 60%, mainly from 30 to 50% aqueous acetic acid solution.

The optimal volumetric ratio of components A and B is from 15: 1 to 6: 1, mainly 10: 1. It is advisable to mix components A and B in an ejector mixer, and the mixture of components A and B immediately foams in the ejector foam generator to form a quick-hardening foam with a multiplicity of 2–60 with silica sol formation and polycondensation of silica sol with a sol-gel transition of silica to form a foamed silica gel with a set of its hardness when using the above components in the specified ratio for 1 second to 2.0 minutes and a change in its volume of not more than 10% for 24 hours owls.

As a result of the extraction and separation of moisture from the foamed silica gel, a solid ceramic foam material is obtained based on the foamed silica gel, which, while maintaining the foamed structure, has thermal stability when exposed to a temperature of at least 1000 ° C for up to 60 minutes, which allows the use of the obtained foamed silica gel and ceramic foam material based on foamed silica gel as an effective fire extinguishing agent in the fire and explosion prevention and solid fire extinguishing.

As the studies of the authors showed, it is advisable to mix the components A and B by means of an ejector mixer immediately before foaming the mixture of components A and B, and foaming the mixture of components A and B should be carried out immediately after mixing the components A and B of the ejector foam generator.

The resulting quick-hardening foamed silica gel foam has good adhesion to various fire extinguishing objects, including vertical and inclined metal surfaces, and high structural and mechanical resistance to adverse effects of external factors, such as heat fluxes and wind.

Concentrations and conditions for the mutual dispersion of alkali metal silicate and silica ash formation activator, as well as the concentration and chemical properties of sodium silicate and foaming surfactant, have a significant effect on the process of ash formation and foaming during foaming, and therefore the choice of specific concentrations and specific components of the foaming surfactant -active substance and silica ash formation activator may vary in specific cases. As the studies conducted by the authors showed, mixing components A and B and foaming the mixture of components A and B with the formation of foamed silica gel is advisable in the time range from 1 to 5 seconds, during which the mechanical strength of the gel of silica nanoparticles is set with the formation of a subhard mass of foamed silica with viscosity up to YuOPa, which, as you know, corresponds to the concept of a solid state of a substance.

In addition, within this time range, foams are usually fed to the fire from a distance of 10 m or more.

The growth of monomer chains of silica nanoparticles as a result of polycondensation of silica sol nanoparticles leads to an increase in their average hydrodynamic radius and, consequently, to an increase in coagulation contacts between silica sol nanoparticles.

Due to the high homogenization of the mixture of a solution of alkali metal silicate with a surfactant and a solution of an activator of ash formation during air-mechanical foaming at the stage of formation of a silica sol, an energy barrier is achieved that determines the possibility of chemical interaction of individual monomers of a silica sol through a layer of foam walls equilibrium in thickness as a dispersion medium, occurs in the entire volume of the foamed mixture of components with a sufficiently high homogeneity.

This allows a sufficiently high speed to ensure the transition of the mixture of solutions from the state of the silica sol to the state of the silica gel with the formation of rapidly hardening foamed silica gel.

Further polycondensation of the particles of silica sol in the silica gel in the foam results in the release of chemically bound water molecules and the densification of the formed inorganic polymer of foamed silica with the release of water and dehydration.

External factors, for example, the effect of high temperature during a fire, can accelerate the stage of water release and dehydration, and the increase in the thermal stability of the inorganic silica polymer will be proportional to the amount of chemically bound water molecules released, which ultimately increases the fire extinguishing ability of the foamed silica gel. As a result of the physico-chemical process described in detail, a foamed silica gel is obtained, which, according to the results of the studies conducted by the authors in an undehydrated state, has the following basic properties and characteristics:

contains May. %, 13-65%, mainly 20-50% silica, 1 -15%, mainly 6% foaming surfactant, water - the rest:

has a bulk density of 0.1 -0.8 g / cm ³ ;

has a volume stability of at least 22 hours with a change in volume of not more than 10%.

In the dehydrated state, foamed silica gel

has a bulk density of 0.05-0.1 g / cm ^{3 and}

has a plastic gel structure with a multiplicity of 2 to 20;

has a hardness in terms of viscosity of more than 100 Pa s;

has a white or yellowish white color.

A foamed silica gel in an advantageous embodiment of the invention is prepared by ejection mixing and ejection foaming of a mixture of an aqueous solution of 10-70%, mainly 20-50%, sodium silicate, and 1-15%, mainly 6%, with a synthetic hydrocarbon blowing agent, from 1 to 6% , mainly 20 to 50% aqueous solution of acetic acid, with a mass ratio of an aqueous solution of sodium silicate with a foaming surfactant and an aqueous solution of acetic acid from 15: 1 to 5: 1, mainly 10: 1.

Foamed silica gel is obtained on the basis of an aqueous solution of a silica sol formed during the hydrolysis of a foamed mixture of sodium silicate solution with a foaming agent with a pH of 10.5 to 12.0 and an ash activating agent with a pH of 1 to 5 when using an acid solution or with a pH of 3 up to 8 when using a salt solution, with a hydrodynamic radius of silica particles of not more than 50 nm with air-mechanical ejection foaming of a solution of silica sol during the growth of silica monomers to an average silica sol diameter of 100 nm with a set of mechanical strength in terms of dynamic viscosity from 20 MPa-s to 100 Pa s in the time range of 1-10 seconds.

The indicated general and predominant technological parameters are determined as a result of the studies carried out by the authors, while upon receipt of the foamed silica sol, the proposed method can also use solutions of alkali and alkaline earth metal silicates, in particular sodium silicate, as the most common alkali metal silicate in industrial production, and can also be used foaming surfactants of various grades, in particular foaming agents for fire fighting I stamps by-6TST, "Firex" NSV Software TF-6 and others, satisfying the conditions of preservation of stability over time, is in a mixture with an aqueous solution of sodium silicate, and without changing its chemical composition;

The soluble alkali metal silicate of lithium, potassium, sodium, commonly referred to as "liquid glass", is a viscous liquid with the general chemical formula R2 O tZyug-pNgO (where R2 O is an alkali metal oxide, m is the module of liquid glass) with a density of 1400-1500 kg / m ³ and a dynamic viscosity coefficient of up to 1 Pa s.

Liquid sodium glass mixes with water in any proportions and when contained in a fire extinguishing composition in the indicated amount (10-70%, mainly from 20 to 70%), the solution viscosity changes from 6 mPa s to 40 mPa-s with a change in the density of the solution from 1020 kg / m ³ to 1250 kg / m ³ .

In the specified range of concentration of water glass in the composition of an aqueous solution, the viscosity of the solution increases by 4-500 times compared with the viscosity of water (0.001 Pa s, 20 ° C). Such a change in the viscosity of aqueous solutions used to extinguish fires is practically unattainable when using organic or inorganic thickeners.

In addition, when dissolving liquid glass in water, the density of the solution increases significantly, which contributes to an increase in the kinetic energy of the movement of the jet of fire extinguishing solution or foam in comparison with the energy of the jet of water directed into the combustion chamber at the same speed. The range of the jet of fire extinguishing solution or foam also increases.

When preparing the proposed fire extinguishing agent, it is necessary to use liquid glass with a module m = Si02 / R20 = 2.5-3.2. This range selection is based on the economic feasibility of using the most industrially common and affordable liquid glass compositions.

The designated interval of the silicate module allows you to significantly reduce the cost of its application, providing a positive economic effect on the final product. However, it is allowed to use another module with a slight deviation from the set in the range of ± 0.5.

This interval covers almost all types of liquid glasses produced by industry.

The shelf life of a liquid glass solution in sealed metal containers is virtually unlimited and does not cause metal corrosion.

The concentration of reagents was selected from the conditions that the set hardness of the foamed substrate from a silica sol during the transition to the silica gel state is accompanied by a set of viscosity up to 10–10 s for a specified time interval of 1–10 seconds.

The lower value of the set time interval (1 s) is determined based on the minimum possible time of homogenization of a mixture of solutions with simultaneous foaming.

The upper value of the set time interval (10 seconds) was determined experimentally on the basis of visual observation of the deterioration of the structural and mechanical parameters of the foam at fire extinguishing objects.

With intensive homogenization of a mixture of component B (mainly an aqueous solution of acetic acid) and component A, consisting of a mixture of an aqueous solution of a surfactant and an alkali metal silicate, a silica sol can be obtained, which is promising for obtaining a foamed silica gel, however, the key parameters in this case are the concentrations of silicate and activator of ash formation, the conditions of mixing and foaming of the components, which were determined experimentally by the authors as a result of field studies IAOD. The studies took into account such indicators as the stability of the foam material, the structure of the foam material, the multiplicity of the foam material, fire extinguishing properties and heat resistance of the foam material.

Stability is characterized by a period of time during which the foams did not change their volume (i.e., a decrease in volume of 10%).

The structure of the foamed material was evaluated visually after hardening and drying (after about 3 days at a temperature of 25 ± 5 ° C).

The multiplicity of the foam was determined by the gravimetric method.

Fire extinguishing properties - time of extinguishing a model fire center 1 A.

Heat resistance - preservation of the structure and properties of the material when heated to a certain temperature, above which partial melting of the surface layer begins and its compaction.

It is known that one or more of the following three principles of operation are the basis for the operation of conventional fire extinguishing means:

1) water base: sprayed water supply for filling tongues of flame and cooling the combustion zone to a temperature below the ignition point in order to extinguish the flame;

2) dry powder or foam: surrounding the ignition zone with wet foam or dry powder in order to limit the flames, block the combustion of oxygen and, as a result, extinguish the flames;

3) preventing oxygen from entering the ignition zone or displacing oxygen from the ignition zone with the creation of conditions under which combustion cannot continue

A distinctive characteristic feature of the invention is the ability to obtain a foamed silica gel forming a quick-hardening foam obtained by mixing air and two liquid components of a fire extinguishing agent: component A - an aqueous solution of a mixture of alkali metal silicate, mainly sodium silicate, and a foaming surfactant, mainly synthetic hydrocarbon blowing agent, and component B - silica-forming ash activator, mainly in the form of an aqueous solution of predominantly acetic acid.

The extinguishing agent in the present invention is a foamed silica gel forming a rapidly hardening foam obtained by ejection mixing of component A and component B and ejection foaming of a mixture of components A and B with atmospheric air.

Component A is an aqueous solution of a mixture of an alkali metal silicate, mainly sodium silicate and a foaming surfactant, mainly a synthetic hydrocarbon blowing agent, with a pH of 10.5 to 12.0, in a ratio of, wt.%, 10-70%, mainly 20-50% sodium silicate, 1-15%, mainly 3-6% of a foaming surfactant, water - the rest.

The optimal volume ratio of components A and B of the indicated concentrations is from 15: 1 to 6: 1, mainly 10: 1.

According to the invention, components A and B are mixed by means of an ejector mixer, and a mixture of components A and B is foamed by an ejector foam generator with the formation of a quick-hardening foam of foamed silica gel with a predominant magnitude of 2 to 60 with the occurrence of silica sol formation and polycondensation of silica sol with sol gel transition of silica and obtaining a foamed silica gel with a set of its hardness for 1 second to 2 minutes and a change in its volume in the hardened with standing no more than 10% within 24 hours.

As a result of the excess moisture from the foamed silica gel, a solid ceramic foam material is obtained based on the foamed silica gel, which, while maintaining the foamed structure, has thermal stability when exposed to a temperature of at least 1000 ° C for up to 60 minutes, which makes it possible to use the obtained foamed silica gel and foam ceramic material based on foamed silica gel as an effective fire extinguishing agent for extinguishing and fire prevention, including by creating fire resistant foamy barriers. If necessary, the resulting solid inorganic foam (solid foam-ceramic material based on foamed silica gel) can be mechanically destroyed to obtain finely divided silica powder S1O2, which in essence is an environmentally friendly finely divided ordinary silica sand S1O2.

Thus, the fight against fires and flame by means of a foamed silica gel forming a quick-hardening heat-resistant foam is carried out by using concentrated components with an effective combination of all the factors of individual advantages of various types of known fire extinguishing agents.

Specific technical advantages of fire prevention and solid extinguishing are as follows:

1) free, physically and chemically bound water of foamed silica gel lowers the temperature of the ignition zone, absorbing latent heat and preventing the spread of flame;

2) the foamed silica gel forms an excellent heat-resistant and heat-insulating layer, limiting the hot ignition zone, which, despite cooling due to process (1), can radiate heat, spreading it to the adjacent water-cooled zones;

3) the solid foam of foamed silica forms a coating layer in the form of a protective heat and gas insulating fire-resistant coating that prevents the ignition and explosion of dust-gas-air mixtures and the subsequent combustion and / or spread of burning of combustible materials caught under this coating layer of solid foam of silica foam or outside it;

4) solid silica foam with nanosized silica particles creates between the combustible material not yet covered by fire and atmospheric oxygen a barrier to oxygen, which is necessary for chemical oxidation reactions during ignition, explosion, and combustion;

5) nanosized particles of silica due to the formation of a volumetric lattice structure not only retain water well, but also ensures adhesion of fine particles of silica to the fire extinguishing object, and quick-hardening foam, in contrast to water and ordinary liquid air-mechanical water foam, which rapidly settles and drains with vertical, inclined and uneven surfaces, provides the formation of a solid foam heat and gas insulating barrier (Fig. b).

The main technical characteristics of the proposed device for solid-state fire extinguishing and fire prevention foamed silica gel are shown in table 1.

Table 1

Main technical characteristics of the device for solid-state fire extinguishing and fire and explosion prevention by foamed silica gel

The main parts of the device for fire prevention and solid-state extinguishing by foamed silica gel are a container with a component A, a container with a component B, an ejector mixer of components A and B, and an ejector foam generator for foaming a mixture of components A and B.

A device for fire prevention and solid-state quenching with foamed silica gel works as follows: Component A under pressure of compressed air in the container of component A is fed into the ejector mixer through the pipeline of component A, in the mixing chamber of which a vacuum is created, under which component B with the open tap of the pipeline of component B enters the mixing chamber of the ejector mixer, where it is mixed with component A .

The mixture of components A and B from the ejector mixer immediately enters the ejector foam generator, where atmospheric air is ejected through the corresponding holes, foaming the mixture of components A and B.

In the ejector mixer, a quick and effective mixing of concentrated solutions of components A and B takes place, and in the ejector foam generator, the foaming of the mixture of components A and B is effective foaming with the formation of quick-hardening silica gel foam, which is sent to the fire prevention and extinguishing zone.

When extinguishing a fire, a device for explosive fire prevention and solid-state extinguishing by foamed silica gel can be served by one person.

Practical tests of the feasibility of achieving a technical result and industrial implementation of the method of the device were carried out in the open air at a temperature corresponding to the operating temperature range of the fire extinguisher used and a wind speed not exceeding 5 m / s, in the absence of precipitation.

According to GOST 51057-2001, the model fire site 1A was a wooden stack in the form of a cube placed on a solid support in such a way that the distance from the base of the stack to the supporting surface was 400 mm.

As a combustible material, 72 softwood bars were used no lower than the third grade according to GOST 8486-86, section 40 mm, length 500 mm, humidity 10-20%.

The stack contained 12 layers of 6 bars in each layer, laid out so that the bars of each subsequent layer were perpendicular to the bars of the underlying layer with the formation of rectangular channels throughout the stack. The free surface area of the model center was 4.7 m ² Under the stack was a metal tray for flammable liquid with a size of 400x400x100 mm, into which 5.0 dm ³ was poured to form a continuous, even surface and 1, 1 dm ^{3 of} summer type gasoline, which meets the requirements of GOST R 51105-97.

A pallet with a flammable liquid was placed under the stack so that the centers of the stack and the pallet coincided.

They set fire to gasoline in the pan and after 8-10 minutes from the moment of the start of burning, when the stack was covered with flames from all sides, they began to extinguish the model fire with various fire extinguishing agents.

During extinguishing, the fire was imparted rotation at a speed of 3-5 rpm, which allowed the extinguishing agents to be supplied to each side of the fire successively and without operator intervention, excluding the influence of the human factor.

Extinguishing using the proposed solid-state fire extinguisher was carried out with the supply of quick-hardening foam from foamed silica gel with a flow rate of 0, 9-1, 1 l / s at a pressure of 0.7-0.8 MPa at a distance from the barrel to the fire of 4-6 m. A fire extinguisher was installed stationary.

After the visually observed end of the quenching of the model site by various fire extinguishing compositions, the time until re-ignition was recorded.

The model fire site was considered extinguished if within 10 minutes there was no re-ignition followed by steady burning of the stack.

The calculation of the extinguishing efficiency indicator was calculated by the formula:

Where:

s is the area of the extinguished object, m ² ;

Q - total consumption of extinguishing agent for extinguishing an object, l;

t is the extinguishing time of the object, s.

In the table. 2 presents the results of comparative tests of fire extinguishing efficiency under identical conditions for various fire extinguishing agents: sprayed water from a water fire extinguisher; air-mechanical foam based on a solution of various blowing agents from a conventional air-foam fire extinguisher; quick-hardening foam of foamed silica gel from the proposed fire extinguisher of fire and explosion prevention and solid extinguishing by foamed silica gel.

Table 2.

The results of comparative tests of extinguishing a model fire 1A according to GOST 51057-2001

The use of the proposed method and device for the purposes of explosion and fire prevention is advisable in the initial stage of emergency situations in enclosed spaces and in open areas with the possible ignition of combustible materials or for extinguishing already ignited materials, as well as in the event of spills of emergency chemically hazardous substances (AXW), the intense evaporation of which can lead to the formation of explosive and flammable gas mixtures, as well as protection against overheating of explosive substances when they are heated from a fire.

As field tests showed, the operative coating of hardening silica gel foam with the surfaces of emergency bottling of flammable liquids and explosive objects provides a sharp decrease in the rate of evaporation of flammable liquids and heating of explosive objects within a few seconds, which ensures quick and effective fire prevention and extinguishing at the very beginning of emergency situations

Improving the reliability of the functioning of the device is ensured by the possibility of priority feeding component A to the foaming agent and mixing components A and B directly in the foaming agent, namely, they are capable of sequentially supplying component A and then component B to the means of spraying and foaming the fire extinguisher, and then component B at the end of the operation of the fire extinguisher, the sequential cessation of supply to the means of spraying and foaming the fire extinguisher in of component B and then component A. This not only completely prevents the possibility of solidification of the foamed silica gel inside the pipeline for supplying the extinguishing agent to the foaming agent and inside the foaming agent, but it also provides the possibility of repeatedly switching the extinguisher on / off and its normal use repeatedly until the charges of components A are fully developed. and B.

Thus, the use of the proposed fire extinguisher ensures the achievement of a technical result, namely, it significantly increases the reliability of the fire extinguishing device and the efficiency of fire extinguishing with quick-hardening foam from silica gel foam, and also proves that all the essential features of the invention are in causal connection with the technical result obtained from using the invention. Specific materials, design features and manufacturing techniques of a fire extinguisher and / or its individual parts are selected in the usual way in relation to the specific conditions of its operation.

The manufacture of prototypes and the above examples of tests in real conditions showed confident achievement of the technical result.

As individual elements and assemblies of the proposed solid-state fire extinguisher, various fire fighting materials, materials, and structural solutions commonly used in the manufacture and use of fire extinguishers can be used.

The analysis also shows that all the general and particular features of the invention are essential, since each of them is necessary, and all together they are not only sufficient to achieve the purpose of the invention, but also make it possible to realize the invention in an industrial way.

Given the novelty of the essential features, the technical solution of the problem, the inventive step and the materiality of all general and particular features of the invention, proven in the section "prior art" and "Disclosure of the invention", proven in the section "Implementation of the invention" technical feasibility and industrial applicability of the invention, a successful solution the inventive task and the confident achievement of the required technical result in the implementation and use of the invention, in our opinion, Noah invention meets all the requirements for eligibility requirements for inventions.

Claims

The method of fire prevention and solid quenching by foamed silica gel and a device for its implementation (claims)

one . A method of fire prevention and solid quenching, which includes the preparation of foamed silica gel in the form of quick-hardening foam by mixing component A in the form of an aqueous solution of a mixture of alkali metal silicate and a foaming surfactant with component B in the form of an activator of silica ash formation and foaming of a mixture of components A and B,

characterized in that

as component A, an aqueous solution of a mixture of an alkali metal silicate, preferably sodium silicate, and a foaming surfactant, mainly a synthetic hydrocarbon blowing agent, is used, in a ratio of May. %, 10-70%, mainly 20-50% of alkali metal silicate, 1-15%, mainly 3-6% of a foaming surfactant, the rest is water, and

as component B use 20-60%, mainly from 30-50% aqueous solution of predominantly acetic acid,.

2. The method according to p. 1, characterized in that components A and B are used with a volume ratio of from 15: 1 to 6: 1, preferably 10: 1.

3. The method according to p. 1, characterized in that components A and B are mixed immediately before foaming, and the foaming of a mixture of components A and B is carried out immediately after mixing components A and B.

4. The method according to p. 1, characterized in that the components A and B are mixed by means of an ejector mixer, configured to eject component B into the stream of component A.

5. The method according to p. 4, characterized in that the components A and B are mixed by means of an ejector mixer configured to eject component B into the flow of component A under the influence of excess pressure of compressed air in the container with component A.

6. The method according to p. 4, characterized in that when mixing the components a and B in the ejector mixer first serves component a and then component B, and at the end of mixing the components A and B, first, the feeding of component B to the ejector mixer is stopped, and then the feeding of component A to the ejector mixer is stopped.

7. The method according to p. 1, characterized in that the foaming of the mixture of components a and B is carried out by means of an ejector foam generator,

8. The method according to p. 7, characterized in that the foaming of the mixture of components A and B is carried out by means of an ejector foam generator configured to eject atmospheric air into a mixture of components A and B.

9. The method according to p. 1, characterized in that the mixing of components A and B and foaming the mixture of components A and B is carried out to obtain a foamed silica gel with a set of its hardness for from 1 second to 2 minutes and a change in its volume in the solidified state more than 10% within 24 hours.

10. The method according to p. 1, characterized in that the mixing and foaming of components A and B is carried out to obtain a solid ceramic foam material based on foamed silica gel, which has thermal stability at a temperature of 1000 ° C for at least 60 minutes, which.

has a bulk density of 0.1 -0.8 g / cm ³ ;

and in a dehydrated state

has a bulk density of 0.05-0.1 g / cm ^{3 and}

has a plastic gel structure with a multiplicity of 2 to 20;

has a hardness in terms of viscosity more than YuOPa s;

has a white or yellowish white color.

11. A device for fire and fire extinguishing and solid extinguishing, containing containers with the components of the extinguishing agent, piping components of the extinguishing agent, a means of mixing the components of the extinguishing agent and a means of foaming the mixture of components of the extinguishing agent,

characterized in that

made with the possibility of obtaining foamed silica gel as a fire extinguishing agent in the form of quick-hardening foam, obtained by mixing and foaming a mixture of component A in the form of an aqueous solution of a mixture of alkali metal silicate, mainly sodium silicate, and a foaming surfactant, mainly synthetic hydrocarbon foaming agent, ratio, May. %, 10-70%, mainly 20-50% of alkali metal silicate, 1-15%, mainly 3-6% of a foaming surfactant, the rest is water,

with a volume ratio of components A and B from 15: 1 to 6: 1, mainly 10: 1.

12. The device according to p. 11, characterized in that it is configured to implement the method according to any one of paragraphs. from 1 to 6.

13. The device according to claim 11, characterized in that the means for mixing the components A and B of the extinguishing agent is made in the form of an ejector mixer with the possibility of ejecting the component B into the component A and is located immediately before the means of foaming the mixture of the components of the extinguishing agent.

14. The device according to p. 1 1, characterized in that the foaming agent of the extinguishing agent is made in the form of an ejector foam generator with the possibility of foaming a mixture of components A and B with ejected atmospheric air.

15. The device according to p. 1 1, characterized in that it contains a locking trigger and a switchgear, made with the possibility at the beginning of using the serial feed device in means for mixing the components of the fire extinguishing agent, first component A and then component B, and upon termination of use of the device for sequentially stopping the supply of first component B and then component A to the mixture of components of the fire extinguishing agent

16. The device according to p. 11, characterized in that it is arranged to supply component A to the means for mixing the components of the extinguishing agent from the container of component A under the influence of compressed air in the container with component A.

17. The device according to p. 16, characterized in that the container of component A is equipped with a nipple for injecting compressed air into the container of component A and a manometer for monitoring the pressure of the compressed air in the container of component A.

18. The device according to p. 1 1, characterized in that it is made placed on a hand truck with the possibility of its mobile movement.

19. The device according to p. 11, characterized in that the container 8 with component B is made in the form of a satchel with the possibility of carrying it over the shoulders of the operator.