RU2082470C1 - Fire-extinguishing device - Google Patents

Abstract

FIELD: fire-fighting equipment. SUBSTANCE: explosive charge generating fire-extinguishing mixture is installed in body provided with starting unit and layer of granules from ablative material. Outlets are made on segment of sphere to form flat front of fire-extinguishing mixture from discrete jets. Body is placed in shell and endothermally decomposed heat-proof material is located between body and shell. Noncombustible gaseous products of decomposition of body heat insulation pass through channels in its upper part to receiver formed by means of flat springs in the space segment of sphere and granule cooling layer. Explosive charge in body is mounted with guaranteed gap by means of corrugated cylinder. EFFECT: higher efficiency. 3 cl, 1 tbl

Description

 The invention relates to the field of fire extinguishing and is intended for manning vehicles and other vehicles as a portable fire extinguisher, the action of which is based on the use of a generated aerosol combustion inhibitor for volumetric and local fire extinguishing.

 A fire extinguishing mixture in the form of a finely divided condensed phase containing salts of alkali oxides and alkaline earth metals and non-combustible gases is obtained by burning a pyrotechnic composition (RF application N 4925423 from 08.04.91, CL A 62 C 3/00; ed. St. N 217411, class A 62 D 1/00, 1984, UK patent N 2028127 dated 03/05/80, class A 62 C 35/02).

 Known devices that implement the specified method of volumetric aerosol fire extinguishing, which contain a pyrotechnic bomb placed in a heat-shielding enclosure with outlet openings and an ignition unit, during the combustion of which an aerosol is generated (RF patent N 94003573 dated 01.02.94, class A 62 C 3/00) .

 To increase the efficiency of fire extinguishing, in particular, they vary the composition of the pyrotechnic composition, the best inhibitory properties of which are based on alkali metal nitrates and perchlorates (application N 94005063 from 11.02.94, class A 62 C 3/00), or supplement the device with a cooling unit aerosol generated. The cooling unit, where the temperature of the extinguishing mixture is reduced, is structurally an air-injection cylindrical nozzle (RF patent N 2008045 dated 02.11.92, class A 62 C 3/00), or a flame arrestor made of a layer of granules of ablative material (ed. St. N 598610, publ. 25.03.78 and N 1309991, publ. 05.15.87, class A 62 C 4/00).

 The most advanced device for aerosol fire extinguishing, in which the indicated technical solutions are synthesized, is selected by the author as a prototype in essence and the number of matching features is the invention (RF patent N 94020391 of 05.31.94, class A 62 C 3/00), which contains a pyrotechnic block with an ignition unit, successively mounted in a heat-shielding case, a cooling unit made in the form of a filled pellet of ablative material of the cylinder, and an outlet.

As a thermal protection of the casing, a layer of material with high heat-absorbing ability is used, which prevents the casing from heating to a temperature of no higher than 100 ^o C, which is much lower than the ignition temperature of organic compounds and, therefore, the casing cannot serve as a source of ignition of the supporting surfaces.

The cooling of the resulting gas-aerosol mixture is carried out as a result of interaction with the ablative material of granules, selected from a number of carbonates, hydroxides, salt hydrates, due to heat absorption by a chemical reaction, which results in the formation of non-combustible compounds water vapor and carbon dioxide, diluting the emitted aerosol and an additional 150 . 200 ^o C reducing the temperature of the stream.

 However, a disadvantage of the known device is the limited scope: only with a stationary installation to protect closed volumes; the impossibility of practical use of it manually as a portable fire extinguisher to suppress local fires, especially hydrocarbon combustible liquids. Firstly, it is difficult to hold the device by the hot case with unprotected hands, and secondly, the gas-aerosol stream does not cover the area of the fire, which reoccurs after the fire extinguishing, or when burning liquid fuel does not deliver fire, but moves it in space.

 The problem to which the invention is directed is to eliminate the noted drawbacks by creating a hand-held portable device for extinguishing local fires, mainly combustible liquids.

 The required technical result is achieved by the fact that in the known device for aerosol fire extinguishing, comprising a pyrotechnic block with a launch unit and an outlet opening mounted in a thermally protective material by means of an endothermally degradable material and an outlet, between which there is a cooling unit in the form of a layer of granules of ablation material, according to the invention, a number of outlet made on a convex ball segment, which, for example, through flat springs is supported on granules of the cooling unit, a pyrotechnic joint the cabinet is installed with a guaranteed gap, mainly in the corrugated cylinder, and the heat-shielding material is placed outside the casing in the casing, the cavity of which is connected with the volume of the output spherical segment by channels made in the casing above the cooling block.

 Distinctive features provide the invention with an increase in functional reliability, effectiveness and expansion of technological capabilities.

 By placing the outlet openings in a row on a convex ball segment, sharply directed diverging jets are combined at a predetermined distance from the device, thereby forming a flat extinguishing stream of a gas-aerosol mixture of combustion inhibitors. The jet outflow of a gas-aerosol mixture from a number of holes creates air leakage (atomization), their active mixing and cooling.

 The interconnection of the output spherical segment through flat springs with the filling of the cooling cylinder creates a clamp of the ablative granulate in a fixed position during storage, transportation and during the burning of the checker, eliminating the possibility of overlapping output openings and communication channels with a thermal protective shell, which ensures the stability of the design conditions.

 Secondly, the spherical segment by means of flat springs forms a receiver, a cavity for accumulating and mixing gases, equalizing the oscillations with the pressure of the gas-aerosol mixture for subsequent jet ejection through the shaped outlet openings of a smaller section.

 The installation of a pyrotechnic checker in a case with a guaranteed gap maximizes the process of burning the checker over the entire surface and supplying the extinguishing mixture.

 The generated aerosol receives a flow directed along the corrugations to the cooling unit.

 Placing the heat-protective material outside the casing made it possible to more effectively cool the surface of the device to the temperature of the extinguisher by hand with unprotected hands.

 The presence of communication channels with the receiver in the upper part of the housing allows the supply of non-combustible products of edenthermic decomposition of the thermal barrier layer directly under the outlet for diluting the aerosol and additional cooling of the extinguishing mixture.

 In FIG. 1 shows a General view of the device; figure 2 section along aa in figure 1; figure 3 view along arrow B in figure 1.

In the housing 1, a launch unit 2 of a grater type, a pyrotechnic checker 3 and a cooling layer 4 of granules with a diameter of 8 mm of basic magnesium carbonate [4 MgCO ₃ x Mg (OH) ₂ x 4H ₂ O Pyrotechnic checker 3 are selected in the following composition (wt.) :
Potassium nitrate (KNO ₃ ) 50
Potassium Perchlorate (KClO ₄ ) 15
Potassium Chloride (KCl) 10
Magnesium Powder (Mg) 10
Combustible binder, including: Epoxy resin (C ₃ H ₅ O) - 10
Plasticizer, Dibutyl Phthalate 4
Hardener, PEPA 1
The housing 1 is installed inside a plastic shell 5, between which sodium bicarbonate (NaHCO ₃ ) is poured, which, when heated, emits water vapor and carbon dioxide. The shell 5 is closed by a screw cap 6, jamming the ball segment 7, resting flat springs 8 through the grill 9 on the granulate of the cooling layer 4. On the sphere (Fig. 3) segment 7 is a longitudinal row (5 pcs.) Of outlet holes 10 with a diameter of 8 mm. Checker 3 in the housing 1 is mounted by means of a corrugated cylinder 11 (Fig. 1 and 2). The launch unit 2 is closed by a cover 12. In the housing 1 there are made radial channels 13 that connect the cavities of the shell 5 and the receiver 14 formed by the spherical segment 7 and the grill 9.

 The device operates as follows.

 If it is necessary to extinguish the fire, unscrew the lid 12, holding the sheath with the other hand 5. Then, pulling the cord, the start-up unit 2 is activated, the heat pulse of which ignites the checker 3. The end burning of the checker 3 extends to its free lateral surface, while the gas-aerosol formed the mixture along the corrugations of the cylinder 11 enters the layer 4. The heat of hot gases and aerosol products of combustion of the checkers 3 by means of heat transfer through the housing starts the endothermic process of chemical decomposition of sodium bicarbonate in the shell 5. The resulting water vapor and carbon dioxide through the channels 13 are fed into receiver 14, where they are mixed with the gas-aerosol stream passed through the grooves 4 between the layer of ablative material granules cleared while a significant portion of the heat.

 The energy addition of metal powder (Mg) to the composition of the checker 3, which can be used Al and Fe, contributes to the formation of crystallization centers on its oxides. Ablation gas generation prevents the deposition of aerosol on the surface of the granules of layer 4, which does not increase the hydraulic resistance of the cooling unit during operation of the device.

 The gas-aerosol mixture by separate jets, fanning through the outlet openings 10 of segment 7, is ejected under pressure from the receiver 14 and then forms a flat front that covers the mirror of the burning liquid and suppresses the fire by successive movement.

The temperature of the sheath 5 does not rise above 30 ^o C. The average temperature in the extinguishing stream at a distance of 0.2 m from the outlet 10 is 40 ^o C.

 Prototypes of the proposed device design were tested at Moskvich JSC for local fire extinguishing in accordance with the requirements of the international standard ISO / CD21 / SC2 N 146E in classes 3B and A, respectively.

Main technical data of tested generators:
Diameter 80 mm
Length 170 mm
Weight 1.3 kg
Checker weight 150 g.

 For volumetric fire extinguishing according to Class A in the engine compartment of the M-2141 automobile, cotton and synthetic fabrics moistened with gasoline and electric cables with PVC insulation were used as combustible material. Combustible material weighing 100.150 g was placed on the cylinder block and on the supporting structure to the left and right of it.

In order to extinguish a class 3B fire, a pallet with a diameter of 340 mm, a depth of 230 mm, and a wall thickness of 2 mm was used in the tests. Combustible liquid-gasoline in the amount of 3 l on a water cushion (6 l). The fire area is 0.09 m ² .

 The test results are summarized in table.

 Re-ignition in both cases did not occur.

 Therefore, the aerosol fire extinguisher of the proposed design has shown high efficiency in extinguishing a volumetric fire in the engine compartment of a Class A car and meets the basic requirements of the international standard "Fire Fighting. Portable fire extinguishers. Operation and design."

 Detailed documentation for the proposed invention is in preparation for serial production of COT-4 products.

Claims (1)

 A fire extinguisher comprising a trigger device located in the housing, a gas generating device with a pyrotechnic checker resting on a diaphragm with outlet openings, characterized in that it has a gas generating device cooling unit located between the pyrotechnic checker and the diaphragm, and the housing is fixed inside the shell with an annular gap, which filled with endothermally degradable material and communicated with the outlet through radial channels made in the housing and located above the cooling unit waiting for the gas generating device, while the pyrotechnic block is installed in a cylinder with corrugations to direct the gas-aerosol mixture to the cooling layer with a gap relative to the casing, which guarantees the end combustion of the block to its lateral surface, and the outlet openings are placed in a row on a spring-loaded diaphragm, which has a spherical convex shape .

Images