RU2602484C1 - Fire extinguishing aerosol generator - Google Patents

Abstract

FIELD: fire safety.

SUBSTANCE: invention relates to devices for volumetric fire fighting using a gas-aerosol mixture of inhibitors. Fire extinguishing aerosol generator comprises equipped with heat-resistant lining and igniter of external initiation of a cylindrical housing, accommodating functional charge and metal pipeline for communicating combustion chamber with receiver under cover with outlet holes. Coaxial housing of functional charge is made in form of a pyrotechnic cartridge with axial channel, wherein through heat-insulating shell there is a metal pipe, communicates via retarded-ignition device, located in bulk layer of a fire retardant, bounded by transverse mesh diaphragms with gas-generating charge, located under annular insulating bridge, forming receiver, wherein cover is aligned with additional cooler, made in form of a shell equipped with injection windows.

EFFECT: technical result is higher payload.

1 cl, 1 dwg

Description

The invention relates to the field of fire extinguishing, and more particularly to devices for volumetric fire extinguishing by means of a pyrotechnic charge of a gas-aerosol inhibitor mixture generated during combustion, introduced into the protected volume.

The level of this technical field is characterized by the aerosol fire extinguishing generator described in patent RU 2114657 C1, A62C 3/00, 1998, including a cylindrical body, on the lateral surface of which there are many through holes for the exit of the generated gaseous extinguishing mixture.

In the case thermally insulated at the ends with gaskets made of koolin cardboard, a functional pyrotechnic composition block is coaxially installed, during the combustion of which an aerosol is formed containing both gaseous products and high-energy condensed particles forming the dispersed phase of the aerosol, which are effective combustion inhibitors.

Coaxial to the end of the pyrotechnic checker in the case, an electric igniter of external initiation of manual and automatic start from the pulse of the sensors of the standard fire alarm system - detectors of exceeding the temperature level and smoky ™ in the protected volume, is connected to the checker by means of a fire transfer tube.

With a gap of 10-20 mm relative to the diameter of the functional checker, which acts as a combustion chamber, a metal grid is placed that limits the volume filled with ablative bulk material, forming an aerosol cooling unit, which is diluted with gaseous thermal decomposition products (water vapor and carbon dioxide), forming a quenching mixture.

A distinctive feature of the described generator is the complete afterburning of the pyrotechnic composition of the functional checker in the gas phase, which minimizes the content of harmful substances in the extinguishing mixture.

The disadvantage of this generator is the possibility of destruction of the casing from excess pressure developed in a closed combustion chamber that does not have a damping free volume for the accumulation of generated gaseous combustion products and the ablative thermal decomposition of the material of the cooling unit - the main magnesium carbonate.

At the same time, the gas-permeable layer of ablation material is a high aerodynamic resistance for the extinguished extinguishing mixture, which is filtered and a part of the condensed phase (effective combustion inhibitor) settles in it, which reduces the required extinguishing concentration in the protected volume and the fire suppression time increases.

More perfect is the aerosol generator according to patent RU 2346718 C1, АСС 13/22, В01J 7/00, СВВ 13/02, 2009, which is selected by technical essence and the number of matching features as the closest analogue to the proposed one.

The known fire extinguishing aerosol generator comprises a cylindrical perforated housing in which charges from a pyrotechnic composition are distributed, generating an aerosol during combustion, including combustion inhibitors.

Pyrotechnic checkers in the casing are fixed through a layer of building gypsum - structural bearing material, including structurally bound water, evaporated in contact with the hot gases of the generated aerosol.

Between the pyrotechnic blocks in the layer of gypsum, metal pipelines of the combustion chamber communication are fixed under a cover equipped with through smoke exhaust holes and a bottom receiver, which communicates with a reversing output channel, the labyrinth of which is formed by a casing covering a cylindrical body with a gap, which partially communicates with a plate cover, forming them overlap.

The housing, the bottom of the casing and the dish-shaped cover are rigidly connected by a central screed, forming a supporting functional structure.

A feature of the known generator is that the quenching mixture consisting of the generated aerosol diluted with water evaporated from gypsum is transferred from the closed volume of the combustion chamber through pipelines to the bottom receiver, where it is braked, expanded and mixed. The extinguishing mixture is then distributed along the external reversing channel, which is a zigzag labyrinth that acts as a cooling unit due to heat removal and multiple turns of the flow, accompanied by heat transfer.

A disadvantage of the known extinguishing aerosol generator is the complexity of the design with a low payload of functional equipment, that is, the low relative content of the pyrotechnic composition creating the extinguishing aerosol, which increases the consumer cost of fire extinguishing agents.

In addition, during the operation of the known generator, there is a likelihood of secondary sources of ignition due to the fact that the incandescent condensed phase deposited on the generators of the output ring opening flows down to the fireproof surface of the mounting plate and then to the support in the protected room, which is ignited. This is unavoidable because no safety features are provided on the mounting plate to prevent the settled condensed phase from dripping onto the flammable bearing surface.

The technical problem to which the present invention is directed is to increase the functional reliability of an improved design of a compact generator with high fire fighting efficiency.

The required technical result is achieved by the fact that in the known fire extinguishing aerosol generator containing a cylindrical body equipped with a heat-protective layer and an external initiation igniter, in which a functional charge and a metal pipe for communication of the combustion chamber with the receiver under the cover with outlet openings are installed, according to the invention, the coaxial housing has a functional charge in the form of pyrotechnic blocks with an axial channel in which is installed through a heat-insulating shell the metal pipe is connected by means of a retardant igniter located in the bulk layer of flame retardant bounded by transverse mesh diaphragms, with a gas generating charge located under an annular insulating jumper forming the receiver, the lid being combined with an additional cooler made in the form of a shell equipped with injection windows.

Distinctive features of the proposed technical solution made it possible to create a compact aerosol generator of increased fire extinguishing efficiency due to the coaxial structural layout of structural elements, characterized by a multiple increase in payload and which is equipped with an automatic gas purge system with a distributed flame retardant, which increased functional reliability.

The implementation of a functional charge in the form of a pyrotechnic channel checker is necessary to place a communication pipeline inside it, ensuring the compactness of the generator as a whole.

The placement between the central metal pipeline, which serves as a heat convector, and the peripheral pyrotechnic checker of the asphalt board shell is intended for thermal insulation of the pyrotechnic composition from the metal pipe heated by the exhaust products of combustion.

By means of a metal pipe, the combustion chamber communicates with an expansion receiver, which is autonomously located under a lid equipped with distributed outlet openings providing a predetermined diaphragm of the extinguishing mixture at the outlet of the generator.

The direct connection of the upper end of the pyrotechnic block through a retardant igniter with a gas-generating charge, which is a fire-transfer element, provides, through the calculated delay time necessary for the complete extinguishing mixture to exit, the ignition and burning of an additional charge, accompanied by the formation of a large amount of gas, which functions as a working body, carrying flame retardant particles through the mesh diaphragm into the body cavity. In this case, the flame retardant particles are distributed in the transporting gases filling the generator volume.

The placement of a bulk layer (gas-permeable) of flame retardant between the transverse mesh diaphragms is directed to the removal of its particles by the carrier gas under the developed pressure into the generator housing, which is free by then, where the smoldering of the condensed phase deposited on the surfaces of the labyrinth channel is suppressed, thereby eliminating emissions of gaseous combustion products after the end active operation of the generator in the calculated thermodynamic fire extinguishing mode.

The automatically ignited retarding charge of the fire-transfer device from the layer-by-layer burning functional checker when the combustion front exits to the upper end face by means of a localized heat pulse, in turn, initiates the combustion of a gas-generating charge.

The restriction of the gas-generating charge from above by a multilayer annular jumper, which is tightly adjacent to the casing and thermally insulating the shell of the central pipeline, blocks the breakthrough of gases into the receiver, directing the entire gas flow through the permeable layer of flame retardant into the free volume of the generator.

The bulk layer of flame retardant is a permeable aerodynamic barrier through which the generated gases under pressure are distributed in a distributed volume into the free volume of the generator, trapping the flame retardant particles.

Particles of the bulk flame retardant layer, which are combustion inhibitors, are forced into the combustion chamber through the free volume of the housing by the carrier gas at the bottom of which the combustion of the settled condensed phase is suppressed, as a result of which the passive action of the generator ceases, which corresponds to the TTU of its operation.

The annular jumper on the flame retardant layer is also on the opposite side the bottom of the receiver under the cover, where the fire extinguishing mixture coming from the central pipeline, which is formed during the burning of the functional checker, is mixed, cooled and accumulated, raising the pressure by which it is ejected into the protected volume.

In the cylindrical shell adjacent to the generator cover with injection windows, in which the aerosol jet flows dynamically, due to the generated vacuum, the external air is automatically sucked in, where it blows thin aerosol jets, diluting and effectively cooling it, forming a flow of fire extinguishing mixture on exit from the shell.

Therefore, each essential sign is necessary, and their combination in a stable relationship is sufficient to achieve a novelty of quality that is not inherent in the signs of disunity, that is, the technical problem posed in the invention is solved not by the sum of the effects, but by a new super-effect of the sum of the signs.

A comparative analysis of the proposed technical solution with identified analogues of the prior art, from which the invention does not explicitly follow, for a specialist in stationary automatic fire extinguishing devices, showed that it is unknown, and given the possibility of industrial serial production of aerosol generators in the existing pyrotechnic production, conclusion on compliance with patentability conditions.

The essence of the proposed technical solution is illustrated by the drawing, which has a purely illustrative purpose and does not limit the amount of claims of the totality of the essential features of the formula.

The drawing schematically shows an aerosol fire extinguishing generator.

The cylindrical housing 1 of the generator according to the invention is closed at the ends by a thermally insulated cover 2 with distributed outlet openings 3 and a bottom cross member 4 in which an external igniter 5 is fixed.

A functional charge 6 is fixed in the housing 1 from a set of channel end-face pyrotechnic checkers, which are connected to the metal pipeline 8 of the combustion chamber 9 with the receiver 10 under the cover 2 through a heat-insulating tube 7 made of asbestos-cardboard.

At the upper end of the pyrotechnic charge 6 in the layer 11 of the bulk flame retardant is placed a retardant igniter 12, mainly pyrotechnic stopin, adjacent to the gas generating charge 13, covered with a multilayer annular jumper 14, fixed between the housing 1 and the tube 7, forming a receiver 10.

The gas-generating layer 11 of the flame retardant is limited by transverse grids 15 (diaphragms), respectively laid on the upper end of the functional charge 6 and under the gas-generating charge 13.

In the housing 1 mounted radial axis 16 for installation in the pins of the mounting bracket 17, which is mounted on supports in a secure room, carrying a remote control 18 manual start control.

In this case, the generator is rotated on the axes 16, directing its longitudinal axis to the likely source of ignition.

A shell 19 is coaxially mounted on the lid 6, equipped in the lower part with injection windows 20 for actively mixing the intake air with the generated aerosol, as a result of which a quenching mixture flows inside the shell from the open end 19 of the shell.

The temperature of the extinguishing mixture drops sharply in an additional cooler - shell 19 to the level of 80-100 ° C at the outlet.

The generator operates as follows.

In the event of a fire in a secure room from exceeding a predetermined temperature level and / or smoke from the detectors of the fire system, or manually from the remote control 18 on the bracket 17, the generator starts up, respectively, automatically or by the operator.

The control pulse initiates the igniter 5, the force of fire from which the pyrotechnic checker 6 of the end combustion is ignited.

When burning the functional charge 6, an aerosol containing combustion inhibitors is generated, which fills the combustion chamber 9 and through the central channel of the pipeline 8, which acts as a heat exchanger, taking part of the thermal energy from the hot gaseous products of combustion, enters the receiver 10 under the cover 2, where the aerosol is mixed By equalizing the pressure and cooling.

From the receiver 10, the aerosol is ejected through the distributed openings 3 in thin jets into the casing 19, where the external air is ejected inward.

Relatively cold air, tangentially entering the shell 19, blows aerosol jets, effectively cooling it, and mixes, forming a quenching mixture at the outlet of the generator.

The flow of the extinguishing mixture directed to the source of ignition knocks down the flame and fills the enclosed volume of the room. The inhibitors contained in the extinguishing mixture actively interrupt the chain redox reaction, stopping the development of combustion.

When the specified concentration of combustion inhibitors is reached in the protected volume, the fire is completely suppressed.

When the combustion front of the checker 6 goes to its upper end, the flame retardant device 12 is ignited, the time of layer-by-layer linear burning of which is a delay sufficient for the complete combustion of the charge 6.

A heat pulse from a burned-out device 12 ignites a charge 13 that generates a large volume of gases, which increased pressure through the restriction diaphragms 15 and the bulk layer 11 of the flame retardant are ejected into the empty volume of the generator by that time.

With the passage of layer 11, the gases generated by the charge 13 capture the flame retardant particles and disperse them inside the free volume of the generator, where they suppress the smoldering of the settled condensed phase, as a result of which the output of the functional aerosol completely ceases.

Particles of flame retardant carried into the protected volume perform the intended purpose, actively acting on smoldering materials, thereby eliminating the development of fire sources.

Tests of prototypes of generators of the proposed design confirmed the high efficiency of fire fighting, which allows us to recommend it for serial production and delivery to customers.

Claims (2)

1. A fire extinguishing aerosol generator, comprising a cylindrical body equipped with a heat-protective layer and an external initiation igniter, in which a functional charge and a metal communication pipe of the combustion chamber with a receiver under a cover with outlet openings are installed, characterized in that the coaxial housing has a functional charge in the form of pyrotechnic checkers with an axial channel in which a metal pipe is installed through a heat-insulating sheath is communicated by means of a delayed -vosplamenitelnogo device disposed in the bulk layer flame retardant, the limited transverse mesh diaphragms with gas-generating charge disposed under the insulating seal ring, forming the receiver. 2. The fire extinguishing aerosol generator according to claim 1, characterized in that the lid is combined with an additional cooler made in the form of a shell equipped with injection windows.

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