Gas fire protection device (optional part) and gas generating composition thereof

Abstract

The gas fire extinguishing device comprises a cylindrical body with a bottom, a cover and a fire extinguishing gas discharge hole, a gas generating charge and a starting device, and the body is provided with a box body of a cylindrical shell filled with permeable gas. And combustion products of the charge and blind bottoms. The box is connected to the cover and is fixed, so that an annular gap is formed between the main body and the box, the gas generating device is arranged in the box, the gas generating device is arranged in the box, a filter shell is fixed on the outer side of the clamping box, the blind bottom of the clamping box is designed to be detachably connected to a cylindrical shell, and an inner annular protrusion and an outer annular protrusion are arranged on the outer surface of the clamping box. An annular gap is formed between the outer annular protrusion of the bottom of the cartridge and the annular protrusion of the bottom of the cartridge. A gas generating composition intended for the inventive device is also presented. Highly purified combustion products are obtained from finely dispersed solid phases while simplifying generator manufacturing techniques.

Description

Technical Field

[0001] The present invention relates to the field of fire extinguishing, namely to devices for generating fire extinguishing gases (gas mixtures) due to the combustion of compositions, the combustion of which generates fire extinguishing gases (gas mixtures) that do not contain ozone depleting substances. The invention can be used as an independent device for extinguishing fires in conditionally sealed spaces, as well as for the manufacture of other devices that use such gases or gas mixtures to generate pressure in tanks (modules) to displace fire extinguishing agents: powders, water or aqueous solutions and other compositions. Background Art

[0002] A gas extinguishing device is known (patent RU 2465937 C1, published on November 10, 2012), which relates to a cryogenic solid fuel device for generating an inert gas mixture and which can be used as an independent gas extinguishing device in a confined space. The known gas extinguishing device comprises an igniter, a charge of an azide-free gas generating composition based on a mixture of potassium nitrate and ammonium nitrate, and a central blind channel in which a sample of the ignition composition is placed. The cylindrical housing, with a sealed cover, is a filter-cooler made of flaky or granular sodium bicarbonate. In this case, the cover is fixed to the end of the cylindrical body of the device, opposite to the bottom, with holes for the discharge of the extinguishing gas, the charge is made in the form of a single block or at least two grids, the charge body is provided with holes arranged uniformly along its sides and along its height and closed opening elements, the bottom of which is made into a silencer. In this case, the device is equipped with a filter separator from the bottom, separated from the filter cooler by a metal mesh, mounted on the body of the device with a gap, made of corrugated filter paper, rolled into a cylinder, provided with a metal mesh on the inner and outer sides, with a top blind plate at the end, with a central hole at the bottom, and provided with a metal cover. In addition, the mesh that defines the filter separator along the outer side surface is covered with a breathable fabric. After the filter separator, a disk is installed, which is made of a thinner part in the center or the hole is blocked by an open element, which is pressed to the neck of the bottom of the device body with a gasket and a pipe nut, while the filter cooler is placed to fill the entire free internal volume of the body of the device, and the ratio between the components of the gas generating composition charged is selected to ensure that the oxygen balance is close to zero.

[0003] The disadvantages of the gas fire extinguishing device according to patent RU 2465937 are as follows.

[0004] A first disadvantage is that the device according to patent RU 2465937 is essentially characterized as an aerosol fire extinguishing device, since, as indicated in the description, not only gases (nitrogen, carbon dioxide) and water vapor participate in the extinguishing process, but also condensed solids.

[0005] The boundary between aerosol and gas fire extinguishing devices can be determined by the extinguishing capacity value of the substance produced by the device.

[0006] Source (see Table 1.7): Agafonov VV, Kopylov NP Problems of design, installation and operation of aerosol fire-extinguishing devices: an educational and methodological manual Kopylov NP. ed. - Moscow: All-Union Scientific Research Institute of Fire Protection, 2001 - 115 pages, providing data comparing the extinguishing capacity of gaseous extinguishing agents (including nitrogen and carbon dioxide) with that of aerosol-forming compositions:

[0007] Table 1 - Comparison of fire extinguishing capabilities of materials

[0008]

[0009] In Appendix D of the regulatory document: СП485.13500.2020 Fire-fighting systems. Automatic fire-fighting systems.

[0010] Design standards and rules: approved and implemented by order of the Ministry of Civil Defence, Emergency Situations and Disaster Relief of the Russian Federation dated August 31, 2020 N 628: implementation date March 1, 2021, by the Federal Register of Technical Regulations and Metrology, October 7, 2020 / Federal Register of Technical Regulations and Metrology Electronic resource: [website]. URL:

[0011] https: / / protect.gost.ru / document.aspx?control=7&baseC=101&RegNum= 54&DocOnPageCount=15&page=21&id=239355(Accessed on December 13, 2022), extinguishing various gases The standard extinguishing concentration of bulk substances is given in volume percentage. Table 2 gives the recalculation of the mass concentration (in kg / m3 as the unit).

[0012] Table 2 - Standard extinguishing gas concentrations for extinguishing various substances

[0013]

[0014] According to the specification of the invention RU 2465937, when tested in a volume of 1 m3, a gas-generating composition with a mass of 240 g (0.24 kg) was used to extinguish the fire, i.e., an extinguishing concentration of 0.240 kg / m3. This value is significantly lower than the extinguishing concentrations of nitrogen and carbon dioxide used for extinguishing fires according to the invention RU 2465937 (Table 2). Fire extinguishing with carbon dioxide and nitrogen is carried out by diluting the air in the protected space and reducing the oxygen concentration therein to a level that does not support combustion. Other extinguishing mechanisms - cooling and suppression of the chain reaction of combustion - are not inherent to these gases. Therefore, if the extinguishing concentration value is lower than the concentration of each gas extinguishing the fire individually (for N2 0.240 < 0.405, for CO2 0.240 < 0.656), it is necessary to check in what proportion all extinguishing gases are mixed with the air in the protected volume.

[0015] Such a check can be carried out if the composition of the gaseous extinguishing agent is known. The composition is published on the official website of the patent holder JSC Itochnik Plus at: https: / / antifire.org / wp-content / uploads / 2022 / 08 / Pasport-GGPT-1-s-izm.pdf, In the passport of the gas fire extinguishing generator GGPT-1.0, its design and layout diagram ( Figure 1 and Figure 2 ) is made according to patent RU 2465937.

[0016] Table 3 - Composition of gaseous fire extinguishing agents (RU 2465937)

[0017] Element Volume content% <![CDATA[CO2]]> 37,5 <![CDATA[N2]]> 22,5 CO 7,4 <![CDATA[H2]]> 3,0 <![CDATA[H2O]]> 29,1 <![CDATA[O2]]> 0,2 <![CDATA[CH4]]> 0,3

[0018] For the GGPT-1.0 generator, the mass of the gas composition is 0.25 kg. If it is assumed that only gas is formed when the solid component burns, without solid particles, the volume fraction of each component when the extinguishing gas is mixed with air can be calculated. 3 The mass of the extinguishing gas is 1.2041 kg (0.25 kg of gas mixed with 1.2041 kg of air). Table 4 gives the calculation results of the extinguishing gases CO2, N2 and water vapor.

[0019] Table 4 - Comparative analysis of the extinguishing gas content in the air of the protected volume during operation of the generator according to patent RU 2465937 and the extinguishing gas content when a fire occurs

[0020]

[0021] As can be seen from Table 4, the concentrations of extinguishing gas supplied to the protected volume by the device according to patent RU 2465937, both individually and all together, are significantly lower than the concentrations that ensure fire extinguishing.

[0022] If we calculate the 3 The volume fraction of oxygen in a mixture of air and combustion products of 0.25 kg of the gas generating composition shows that this fraction will be 17.5%. Reducing the volume fraction of oxygen to 17.5% is not enough to prevent combustion. The volume fraction of oxygen must be reduced to at least 16%.

[0023] Calculations have shown that fire extinguishing using gases generated during the operation of the device according to patent RU 2465937 cannot be achieved by dilution (reduction of the oxygen content in the protected volume), and carbon dioxide and nitrogen do not have suppressive properties. Therefore, two other extinguishing processes remain: suppression of the reaction in the flame by active solid particles not retained by the device filter, and cooling by fine spraying of water droplets.

[0024] Taking into account that the declared values ​​of the fire-extinguishing concentrations are in an intermediate position between aerosol and gas devices, the device according to patent RU2465937 can be classified as a fire-extinguishing aerosol generator partially purified of solid particles (reduced content of solid particles).

[0025] Another disadvantage is that in order to avoid the influence of the high temperature of the combustion products on the paper filter separators, they must be cooled by a layer of sodium bicarbonate, which leads to a significant increase in the weight and size of the structure. In addition, the interaction of sodium bicarbonate with the combustion products leads to an additional ingress of water vapor into the protected volume, which is an undesirable factor when protecting cabinets with electrical and electronic equipment.

[0026] The prototype of the proposed gas fire extinguishing device option (claims 1 and 6 of the formula) is the gas fire extinguishing device disclosed in patent RU 2640466 published on January 9, 2018. The known device on January 9, 2018 comprises an outer metal cylindrical body sealed with a cover, a charge of solid chemical substances made of an azide-free gas generating composition is placed inside the body, a central blind cylindrical channel is made of the end facing the cover, and an igniter, and the igniter is placed between the cover and the end of the flat elastic element. The metal outer shell is provided with a perforated inner shell, fastened to the cover by rolling and placed so that an annular grooved gas guide is formed between the outer shell and the perforated inner shell. The charge of solid chemical substances from the azide-free gas generating composition with a central blind cylindrical channel is made of a porous and gas-permeable substance, and the igniter is placed in its channel by particles in a composition selected according to the area of ​​use. In this case, a channel-porous, gas-permeable gas-generating charge is installed without gaps in a perforated shell, one end of which is mounted on a cover with a flat elastic element and the other end is mounted in a blind-bottom tin cup, that is, it is equipped with an inner perforated shell, an outer metal shell is closed by a plug separator with a notch in the cover, and there is a sealed docking unit on the outside.

[0027] The first disadvantage of the invention is the complexity of the product manufacturing technology due to the design features that ensure the purification of combustion products from fine solid particles. The design also includes an internal perforated sleeve that is connected to the outer shell by rolling to form an internal annular gap. The rolling operation complicates the product manufacturing technology because it requires additional tools and equipment.

[0028] Furthermore, there are significant technical difficulties in manufacturing a charge having a closed narrow cylindrical channel to accommodate the igniter. The presence of such a channel is necessary to ensure the layer-by-layer combustion of the porous charge from the inner surface to the periphery and to ensure the co-filtration of the combustion products as they pass through the porous layers, according to the invention.

[0029] The second disadvantage is the inconvenience of operation, because the igniter and ignition initiator are not separate replaceable units, but are placed in the gas generating charge in a cylindrical blind channel. If the integrity of the starting circuit is compromised, this will require complete replacement of the generator at the protection facility.

[0030] A third disadvantage is the low efficiency of the porous housing in filtering fine solids.

[0031] A fourth disadvantage is the presence of flat elastic elements in the form of rubber temperature vibration dampers which may become a source of toxic gases due to thermal damage caused by the high temperatures during combustion of the charge.

[0032] The invention is known from patent RU 2640466, publication no. 9. January 2018, which discloses a gas-generating composition free of azide, containing a phenolic novolac resin, potassium nitrate, basic magnesium carbonate, urea and graphite in the desired proportions. From this composition a channeled porous gas-permeable charge is formed for use as part of a gas generating device, which makes it possible to produce a combustion process which is not volumetric, but layer-by-layer, triggered by an artificial pressure difference between the initial surface, the ignition surface and the final surface, i.e. the surface from which the gases generated in the initial charge flow out.

[0033] The disadvantage of the present invention is that in order for the composition to function properly, special conditions are required, namely the charge made therefrom must have, for example, the presence of through-porosity and gas permeability, as well as a central blind cylindrical channel. The above disadvantages lead to a complication and increased cost in the manufacturing technology of the gas generating charge itself and the gas generator based thereon.

[0034] The flame retardant composition known from patent RU 2610120 published on February 8, 2017 contains 30% to 95% by weight of a compound selected from copper salts and 5% by weight of a flame retardant component. % to 70% by weight. The heat and energy source in the composition is a pyrotechnic compound, which, after ignition, burns, generating high temperatures that ensure the decomposition reaction of the composition, which makes it possible to spray a large amount of extinguishing substances obtained by reaction with the pyrotechnic compound for the purpose of extinguishing the fire. A flame retardant composition based on copper salts, which is able to quickly and effectively reduce the heat generated during the combustion of pyrotechnic charges; significantly reduces the temperature of the sprayed substances, and does not require the use of complex cooling systems in fire extinguishing devices.

[0035] The main disadvantage of the present invention is that the composition cannot be used as a source for producing a "pure" fire extinguishing gas, since the gas produced during its combustion contains considerable amounts of solid combustion products (eg potassium carbonate).

[0036] The closest analogue of the invention proposed in paragraph 12 of the formula is the invention according to patent RU2151135C1, June 20, 2000, which relates to the preparation of a gas generating composition for use in systems for displacing liquid and powdered substances. The gas generating composition contains potassium nitrate, phenolic resin, basic magnesium carbonate and ammonium oxalate monohydrate, and its components are in the following weight ratios. %: potassium nitrate 54.0-60.0; novolac phenolic resin 15.0-24.0; basic magnesium carbonate 5.0-17.0; ammonium oxalate monohydrate 5.0-20.0. As indicated by the source, the composition has high performance: the temperature of the generated gas is low, the specific gas yield is high, and it ensures reliable operation of the gas generator design in the temperature range of minus 50 to plus 50 ° C.

[0037] The disadvantage of the closest analogues is that it is not possible to use the mentioned gas generating composition for generating fire extinguishing gas, since the obtained gas contains methane (greater than 0.05 mole fraction (mol fraction)) and water vapor (0.28-0.35 mole fraction), and contains a small amount of carbon dioxide (no more than 0.16 mole fraction. This limits the application range of the gas generating composition to only pressurizing and displacing liquid and powdered substances. Summary of the invention

[0038] The problem to be solved by the present invention group is to create a gas fire extinguishing device equipped with a pyrotechnic composition, which produces a highly purified fire extinguishing gas mixture, such as carbon dioxide, nitrogen and steam water. Made of fine condensed solid particles of combustion products, the manufacturing process is simple and easy to use as part of the gas fire extinguishing device.

[0039] The technical result is an expanded range of applications, since it can be used both in the form of an extinguishing device for generating extinguishing gases (gas mixtures) and for extinguishing fires of classes A2, B and C, as well as a system for displacing liquid and powdered substances, as well as a system for activating the sol-gel formation process in the production of fast-hardening fire-fighting foams based on foamed silica hydrogels.

[0040] Another technical achievement is to ensure that highly purified combustion products can be obtained from a finely dispersed solid phase while simplifying the manufacturing technology and ensuring easy handling.

[0041] In order to solve this problem and ensure the technical effect, two forms of gas fire extinguishing devices with radial (paragraph 1) and axial (paragraph 6) gas outflow have been proposed, (paragraph 12 and gas generating compositions intended for use in these devices.

[0042] In a first embodiment, a gas fire extinguishing device comprises a cylindrical body having a bottom, a cover and an opening for the discharge of fire extinguishing gas, a gas generating charge and a starting unit. The housing is provided with a box comprising a cylindrical housing, permeable to gaseous combustion products and having a solid bottom. The box is connected to the cover and placed so that an annular gap is formed between the body and the box, while the gas generating charge is installed in the box, and the opening for the discharge of fire extinguishing gas is located in the box. The cylindrical wall of the housing. A fixed filter housing is provided on the outside of the box. The blind bottom of the dark box is designed to be detachably connected to the cylindrical shell and is provided with outer and inner two annular protrusions on the outer surface. An annular gap is formed between the outer annular protrusion at the bottom of the box body and the annular protrusion at the bottom.

[0043] In a second version, a gas fire extinguishing device comprises a cylindrical body with a bottom, a cover and holes made in the bottom for discharging the fire extinguishing gas, a gas generating composition of the charge and a starting unit, the body being provided with a box containing a cylindrical shell and a blind bottom permeable to the gaseous products of the combustion of the charge. The box is connected to the cover and placed so that an annular gap is formed between the body of the device and the box, while the gas generating charge is mounted inside the box. A filter housing is fixed to the outside of the box. The blind bottom of the box body is made in a form that can be detachably connected to the cylindrical shell and is provided with two annular protrusions on the outer surface and the inner surface. The device comprises a perforated disk, on the surface of which there is an annular protrusion mounted in such a way that an annular gap is formed between the outer annular protrusion of the bottom of the box and the annular protrusion on the perforated disk.

[0044] The device of the second embodiment may further comprise a filter cooler placed between the perforated disk and the cover in contact with the bottom.

[0045] In any embodiment of the device, the filter housing can be made of a high temperature resistant fabric, such as a silica fabric. The first elastic element is placed between the cover and the charge, and the second elastic element is located between the inner annular protrusion of the box bottom and the annular protrusion of the perforated disk. The outer annular protrusion of the box body blind bottom has a process hole to ensure its detachable (e.g., threaded) connection with the cartridge body.

[0046] A gas generating composition for the above-mentioned device is also proposed, which comprises a gas generating agent, potassium nitrate and novolac phenolic resin as a combustible binder, and a metal oxalate with a variable valence state is used as a gas generating agent. The component ratios are as follows, weight %:

[0047]

[0048] BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The proposed group of inventions is illustrated by means of the accompanying drawings.

[0050] Figure 1 The general view of an embodiment of a gas fire extinguishing device with radial gas outflow is shown.

[0051] Figure 2 An overall view of an embodiment of a gas fire extinguishing device with axial gas outflow is shown.

[0052] Figure 3 A photograph showing a block of the gas-producing composition during combustion is shown.

[0053] picture Figure 4 A photograph of a red hot rod of a gas generating composition immediately after combustion is shown. DETAILED DESCRIPTION

[0054] In a first embodiment (with radial gas outflow), the gas fire extinguishing device comprises a cylindrical body 1 with a bottom 2, a cover 3 and a hole 4 for the discharge of the extinguishing gas, a gas generating charge 5 and a starting unit. 6. Removable connection with the cover 3. The housing 1 and its components can be made of metal or composite materials. The housing 1 is equipped with a box 7, which contains a cylindrical shell 8 and a blind bottom 9 that are permeable to the gaseous combustion products of the charge 5, and the box 7 is connected to the cover 3 and placed to form an annular gap. The gas generating device 5 is installed between the housing 1 and the box 7, and the gas generating charge 5 is installed in the box 7. In addition, the cylindrical wall of the housing 1 is provided with a hole 4 for the discharge of the extinguishing gas. In this case, the blind bottom 9 of the box 7 can be removably connected to the cylindrical metal shell 8, and two annular protrusions are provided on the outer surface-an outer protrusion 11 and an inner protrusion 10, and the outer protrusion 11 has technical advantages. The inner side of the bottom 2 of the body 1 is provided with an annular protrusion 13 to ensure the threaded connection assembly of the box body and the bottom of the box body. Furthermore, an annular gap is formed between the outer annular convex portion 11 on the bottom of the box body 7 and the annular convex portion 13 on the bottom.

[0055] The gas extinguishing device according to the second version (with axial gas outflow) comprises a cylindrical body 1 with a bottom 2, a cover 3 and holes 4 for the discharge of extinguishing gas formed in the bottom 2, a gas generating device. A charging device 5 and a starting device 6. The housing 1 is equipped with a box 7, which comprises a cylindrical shell 8 and a blind bottom 9 that are permeable to the gaseous combustion products of the charge 5, the box 7 being connected to the cover 3 and placed so as to form an annular gap. The gas generating device 5 is installed between the housing 1 and the box 7, while the gas generating charge 5 is installed in the box 7. The bottom 2 can be made of a flat sheet metal. In this case, the blind bottom 9 of the box 7 can be detachably connected to the cylindrical metal shell 8 and is provided with two annular protrusions on the outer surface - an outer protrusion 11 and an inner protrusion 10, the outer protrusion 11 having technical advantages. The hole 12 ensures the threaded assembly of the cassette with the bottom of the cassette. Furthermore, the device comprises a perforated disk 14 having an annular protrusion 15 on its surface, which is mounted in such a way that an annular gap is formed between the outer annular protrusion of the bottom of the box 11 and the annular protrusion 15 on the perforated disk 14. The device also comprises a filter cooler 16 in the form of a tablet cooler (for example, based on basic magnesium carbonate) and placed between the perforated disk 14 and a cover 17 in contact with the bottom 2. A starting unit 6 comprising, for example, an electric igniter is connected to the cover 3 via a detachable connection. In certain cases, an intermediate block mounted between the firing unit 6 and the charge 5 can be used to ignite the charge. The device can be additionally equipped with a nozzle-gas duct (not shown), mounted from the bottom 2.

[0056] In any embodiment of the device, the box can be equipped with a filter housing 18 fixed to the outside, which is made of one or more layers (1 to 5 layers) of high temperature resistant fabric, for example, high temperature silicon satin woven fabric brand KT-11.S 8 / 3TO. There are air outlet holes 4 on the outside 2 sides of the bottom, which can be closed with a self-adhesive film with warning text.

[0057] A first elastic element 19 is provided between the cover 3 and the charge 5, and a second elastic element 20 is provided between the inner annular protrusion 10 of the bottom 9 of the box body 7 and the annular protrusion 13 of the bottom 2 of the housing. 1 or the annular protrusion 15 on the perforated disk 14. The elastic elements 19, 20 perform multiple functions. The first elastic element 19 provides orientation and prevents the charge 5 from shifting in the box 7, and participates in the formation of the free volume 21 in the box 7 to ensure the effective combustion of the charge 5. The second elastic element 20 is installed to prevent the box body 7 from shifting relative to the central axis of the housing 1 (in other words, to maintain a constant value of the annular gap between the housing 1 and the box body 7), and participates in the fixing of the second elastic element 20. A free volume in the form of a buffer chamber 22 is formed inside the housing 1. Its presence, together with the annular gap provided by the design, ensures the balance of the airflow and its uniform discharge through the opening 4 for the discharge of the fire extinguishing gas. The elastic elements 19, 20 can be compression springs, bending springs, etc.

[0058] The device according to any embodiment of the invention operates as follows. When an electric pulse is applied from the starter unit 6, the charge 5 from the gas generating composition ignites. The combustion products passing through the gas-permeable housing 8 of the box 7 and additionally through the filter housing 18 and the filter cooler 16 (if any) are cleaned of solid particles. Next, the purified extinguishing gas moves along the annular gap and is discharged into the protected volume through holes in the cylindrical wall or on the bottom of the housing. As a result, the oxygen concentration in the protected volume is reduced to a level at which the flame combustion stops.

[0059] Enabling the bottom of the box to be detachably connected to the cylindrical shell simplifies the manufacturing technology of the device, since, compared to the prototype, it eliminates the need for rolling operations for mounting the internal perforated body and forming an annular gap, which required the use of additional tools and equipment. During assembly, the annular protrusion makes it easy to install the elastic element, and the presence of an annular gap between the outer annular protrusion at the bottom of the box and the annular protrusion at the bottom facilitates the installation of the box in the generator housing, ensuring a symmetrical annular gap between the box and the inner surface of the body of the device. Its presence ensures the equalization of the airflow and its uniform exit through the opening for the outlet of the fire-extinguishing gas.

[0060] In the design of the device, a filter housing fixed to the outside of the box, made of a high-temperature resistant fabric (for example, a silica fabric), was introduced, which provided a higher degree of purification of the combustion products from fine solid particles compared to an internal perforated housing. In the prototype, the purification of the combustion products from the condensed liquid and solid particles was essentially a two-stage process: first, the combustion products passed through the porous charge layer, since the combustion occurs from the inner surface to the periphery, and then through the porous charge layer of the internal perforated housing. This cleaning method requires the manufacture of a charge with blind narrow cylindrical channels, which is technically difficult, and therefore the entire design of the prototype is technically difficult to manufacture. In the proposed solution, the filter housing made of a high-temperature resistant fabric not only provides a higher degree of purification, but also simplifies the manufacturing technology of the structure, since it allows the use of a solid propellant charge in simple and easy-to-manufacture forms, such as in the form of a cylindrical single-channel block.

[0061] In the proposed device, metal elastic elements are used instead of elastic rubber shock absorbers to fix the cartridge with the charge and protect it from vibration loads, which makes it possible to avoid the release of toxic gases due to thermal destruction.

[0062] The use of a starting unit in the form of a separate replaceable unit in the design of the proposed device ensures easy operation of the device, since in the event of a breach in the integrity of the starting circuit, the unit can be easily replaced without requiring a complete replacement of the device at the protected location.

[0063] Tests conducted to extinguish a model fire and assess the degree of purification of combustion products of fine solid particles confirmed the feasibility of practical implementation of the proposed technical solution.

[0064] The proposed device options for extinguishing a model fire of n-heptane were tested in a conditionally sealed space in accordance with GOST R 53280.3-2009. The model fire was extinguished, while the oxygen concentration in the protected volume dropped to 14.76-14.95% of the volume in the radial outflow option and to 15.26% of the volume in the axial outflow option, which demonstrates that the mechanism of gas fire extinguishing reduces the oxygen content in the protected volume to a level that does not support combustion.

[0065] The gas generating charge can generally be made based on a composition that does not contain an azide, which specifically contains potassium nitrate, a binder and other components, including a gas generating agent, the combustion of which mainly produces the following combustion products: carbon dioxide (more than 60%), water vapor, and nitrogen. The combustion products are not highly toxic substances and do not contain ozone-depleting substances.

[0066] Metal oxalates of different valence states are used as gas generating agents, such as nickel oxalate dihydrate NiC2O4·2H2O, copper oxalate hemihydrate CuC2O4·0,5H2O, cobalt oxalate dihydrate CoC2O4·2H2O, iron (III) oxalate pentahydrate Fe2(C2O4)3·5H2O, magnesium oxalate dihydrate MgC2O4·2H2O, calcium oxalate monohydrate CaC2O4·H2O, mainly copper oxalate hemihydrate.

[0067] The properties of metal oxalates with different valence states are shown in Table 5.

[0068] Table 6 gives an example of the implementation of one of the proposed inventions - a gas generating composition, indicating the products obtained during the combustion process.

[0069] Table 5 - Properties of metal oxalates of different valence states

[0070]

[0071] Table 6 - Examples of gas generating compositions and indicating the product compositions obtained during combustion

[0072]

[0073]

[0074] To produce the proposed composition, techniques and equipment known in the art are used. The powders of the components of the composition are mixed in the proportions shown in the examples (Table 6); any mixer can be used for mixing. The powder mixture is then formed into a mold and compacted to the desired density. After forming, the composition is heat treated, the time and temperature being selected according to the grade of the phenolic resin.

[0075] As can be seen from the examples of the present invention (Table 6), the combustion of the proposed composition produces a large amount of carbon dioxide CO2, which ensures that the composition can be used not only in the device using a gas mixture to generate pressure, but also in the device to extinguish fires with the generated fire extinguishing gas. We also note that when the proposed composition is burned, only trace amounts of carbon monoxide (CO) not exceeding 0.68·10-5 mole fraction are formed, which ensures safety when using a fire extinguishing device with such a composition.

[0076] The examples show that the compositions based on hemihydrate copper oxalate produce the largest amount of the target extinguishing gas, i.e., CO2. In addition, in Examples 1, 2, and 3, although the content of the gas generating agent is about 1.5-2, the amount of water vapor is 1.5 times less than that in Examples 4, 5, and 6. It is several times higher. Therefore, the compositions based on hemihydrate copper oxalate can be used in those fields where it is necessary not only to suppress fires but also to cause minimal damage to the protected equipment, such as for extinguishing microelectronic devices. Another advantage of the compositions based on hemihydrate copper oxalate (Examples 1-3) is that their combustion temperature (Example 1-913°C) is close to the melting point of the resulting condensed phase, in which the oxidant excess coefficient is less than 1 and is mainly composed of pure copper (copper melting point 1084.62°C). During the combustion of the composition, the copper particles produced soften and melt, and when interacting with each other, a highly porous skeleton is formed, which acts as a filter to filter a small amount of carbon and potassium carbonate solid particles, which are formed as a result of combustion.

[0077] Charges from the proposed composition have been tested in fire extinguishing devices (gas generators) for generating fire extinguishing gas, fire extinguishing modules for kitchen equipment and in systems for producing fast-hardening fire extinguishing foams based on foamed silicic acid hydrogels. As an example, the procedure and test results of the gas-generating composition carried out according to Example 1 are given.

[0078] The charge from the proposed gas generating composition was placed in a fire extinguishing device for generating extinguishing gas. The charge we used consisted of 10 cells with cylindrical channels of 12 mm in diameter. The specified device was installed in a volume of 0.5 m 3The test chamber was sealed and a model fire source was placed inside. In the first case, an A2-class fireplace was used, which was a plate made of plexiglass (polymethyl methacrylate) with dimensions of 105×20×10 (length×width×height), in the second case, a B-class fireplace was used, which was a n-heptane steel plate with a diameter of 80 mm, and in the third case a portable gas burner (C-class model fireplace). After the initial burning of the model fire (30, 30 and 5 seconds for A2, B and C, respectively), the door of the test chamber was closed and the gas generator was started using a pyrotechnic starting device. The flames of the model sources A2, B and C were extinguished 20, 25 and 6 seconds after the start of the gas generator operation, respectively. The process of the model fire stopping combustion was visually recorded through the observation mirror in the test chamber. The extinguishing concentration based on the mass loss of the charge in all three tests was 495 g / m 3 , which is close to the standard extinguishing concentration of pure СO2 for extinguishing fires of solid non-smoldering materials (class A2 fires) and n-heptane, i.e. 34.9 vol.% or mass concentration 637.2 g / m3 (https: / / gazoanalizators.ru / converter / ). The fact that the concentrations differ slightly is due to the presence of nitrogen and water vapor in the gas phase of the combustion products of the proposed composition.

[0079] The charge from the proposed gas generating composition was placed in a gas generator consisting of 3 blocks with cylindrical channels with a diameter of 10 mm, which was then installed inside the fire extinguishing module of the kitchen appliance filled with extinguishing liquid. With the help of a pyrotechnic launch device, the gas generator was started after 3 seconds, the pressure in the gas cylinder reached the working pressure, the launch membrane was activated, and the extinguishing liquid was sprayed on the model fire, which was burning vegetable oil. The release of the extinguishing liquid and the operation time of the gas generator were about 20 seconds. After the start of the spraying of the extinguishing liquid, the model fire was extinguished within 10 seconds.

[0080] The charge from the proposed gas-generating composition is placed in the gas generator of a fire extinguisher to obtain a fast-hardening fire-extinguishing foam based on a foamed silicate hydrogel (the design of which is disclosed in patent RU2749136 published on June 4, 2021). The charge is carried out in the form of a channel-free block, the lower end and the sides are insulated with heat-resistant polymer materials to ensure terminal combustion and increase the gas generation time. After the combustion of the gas generator is started using a pyrotechnic launch device, the generated gas (high in carbon dioxide content) is simultaneously supplied through a pipeline to displace the liquid component. The liquid component is an aqueous solution of an alkali metal silicate and a hydrocarbon surfactant, and the ash gel formation process of the specific liquid component is activated to obtain a foam mass that hardens within 10 seconds at the outlet of the device. The temperature of the released gas does not exceed +110°C, which is mainly due to the low combustion temperature of the proposed composition and the use of a chemical endothermic agent. In this case, due to the high CO2 content in the gas phase of the combustion products of the proposed composition, the ash gelation process of the liquid component of the fast-hardening fire-extinguishing foam can be activated.

Claims

1. A gas fire extinguishing device comprising a cylindrical body with a bottom, a cover and holes for the discharge of extinguishing gas, a charge from a gas generating composition and a starting unit, the body being provided with a box body containing a cylindrical outer shell of gaseous combustion products of the charge and a blind bottom of the box. The box is connected to the cover and placed so that an annular gap is formed between the body of the device and the box, while the gas generating charge is mounted in the box, characterized in that The opening for discharging the fire extinguishing gas is located in the cylindrical wall of the housing. A filter housing is fixed to the outside of the cassette, and the blind bottom of the cassette is designed to be detachably connected to the cylindrical housing and is provided with two annular protrusions on the outer surface and the inner surface, and an annular gap is formed between the outer annular protrusion of the bottom of the cassette and the annular protrusion of the bottom.

2. The device differs from point 1 in that the filter housing is made of a high temperature resistant fabric, such as a silica fabric.

3. The difference from the equipment in point 1 is that the outer annular protrusion of the blind bottom of the box body has a process hole.

4. The device differs from point 1 in that a first elastic element is placed between the cover and the charge.

5. The device differs from points 1-4 in that it comprises a second elastic element fixed between the inner annular protrusion of the box bottom and the annular protrusion on the bottom.

6. A gas fire extinguishing device comprising a cylindrical body with a bottom, a cover and a hole made in the bottom for the discharge of the fire extinguishing gas, a charge of a gas generating composition and a starting unit, the body being provided with a box having a cylindrical housing permeable to the gaseous products of the combustion of the charge and a blind bottom. The box is connected to the cover and placed so that an annular gap is formed between the body of the device and the box. The gas generating charge is mounted in the box, characterized in that The box is equipped with a filter housing attached to the outside. The blind bottom of the box body is made in a form that can be detachably connected to the cylindrical shell and is provided with two annular protrusions on the outer and inner surfaces. The device contains a perforated disk, on the surface of which there is an annular protrusion installed in such a way that an annular gap is formed between the outer annular protrusion of the box bottom and the annular protrusion on the perforated disk.

7. The device differs from point 6 in that the filter housing is made of a high temperature resistant fabric, such as a silica fabric.

8. The device differs from the point 6 device in that the outer annular protrusion of the blind bottom of the box has a technical hole.

9. The difference from the point 6 device is that the outer annular protrusion of the blind bottom of the box has a technical hole.

10. The device from points 1-4 is characterized in that it comprises a second elastic element located between the inner annular protrusion of the box bottom and the annular protrusion of the perforated disk.

11. The device differs from point 6 in that it also contains a filter cooler placed between the perforated disk and the cover in contact with the bottom.

12. A gas generating composition comprising a gas generating agent, potassium nitrate and a novolac phenolic resin as a flammable binder, characterized in that It is intended to be used in the device of paragraphs 1 to 11. A variable valence metal oxalate is used as a gas generating agent, and its component ratio and weight percentage are as follows: Variable valence metal oxalate 32,0-70,0 Potassium nitrate 25.0-54.0 Linear phenolic resin 5,0-14,0

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