RU2370293C1 - Method of disperse gas fire extinction and device for method implementation - Google Patents

Abstract

FIELD: fire safety.

SUBSTANCE: invention concerns fire fighting equipment and is intended for extinction of fires of A, B, C, grades and power plants of up to 7000 V voltage hands-free. Method of disperse gas extinction of inflammable fluids and fuel and suppression of deflagration burning of air-gas and dust-gas formations by feeding disperse gas flow of fire extinguishing fluid from module device to fire area involves formation of inhibiting disperse gas phase with juvenile surface and flegmatising dispersion medium of the disperse gas flow out of supercritical fluid obtained by proposed method, involving pyroelement initiation at shutoff/launching device, simultaneously with thermochemical charge initiation with the help of the claimed device. Device can be applied in automatic and autonomous fire fighting systems and features gas cylinder shutoff/launching device in the form of at least two-layer wad pressed in flushing valve case. Lower wad part contacting gas cylinder content is made of thermomelting foil or plate, and upper external wad part is made of elastic pyroelement with electric igniter commuted to electric pyrocartridge launcher unit.

EFFECT: enhanced fire extinction efficiency in hazardous facilities of coal and ore mining, chemical, oil and nuclear power industries, in transport, industrial facilities and buildings, storehouses and garages, suppressed deflagration burning of air-gas and dust-gas formations.

4 cl, 1 dwg

Description

The invention relates to the field of fire fighting equipment, namely to a gas-dispersed (gas-powder, gas-aerosol, gas-liquid or a combination of them) method of extinguishing fires of classes A, B, C and electrical installations up to 7000 V without human intervention, can be used in hazardous coal, mining, chemical, oil, nuclear industry, transport, industrial buildings and structures, warehouses and garages, as well as to suppress the deflagration combustion of gas and dust formations.

The invention is industrially applicable in automatic and autonomous fire extinguishing systems.

Known methods of extinguishing fires using 2 or more fire extinguishing substances by preliminary mixing, aeration and feeding the formed gas-dispersed mixture into the fire zone. These methods are described in RF patents and PCT application [1-10].

A common disadvantage of these analogue methods is their relatively low quenching of LVH and GF and the inability to quench deflagration combustion.

The closest to the essence of the invention analogues are "Fire extinguishing gas dispersed composition, method of extinguishing and device for its implementation" according to the application No. PCT / RU 2006/000167, published under No. WO 2007/117168 A1, 10/18/2007 with a priority of 06.22.04.04 , and the patent of the Russian Federation No. 2254156 C1, published on 06/20/05 with a priority of 06/22/04, "Method of powder fire extinguishing and device for its implementation."

RF patent No. 2254156 C1 was chosen by us for the prototype because it not only has the maximum number of similar features of the invention by the method of forming a pre-aerated gas mixture and supplying it through nozzles to the fire zone under pressure exceeding the thermal depression of the fire at a speed exceeding the rate of upward heat flow from the fire load, but also in that the phlegmatizing gas stream is obtained by burning a solid fuel charge placed in the cylinder.

The set of actions and the conditions for their implementation in the prototype method provides a flow velocity v≈20-50 m / s and cannot provide suppression of deflagration combustion of gas-air and gas-dust mixtures propagating at a speed of 100-120 m / s (see A.N.Baratova Combustion - Fire - Explosion - Safety. - M; 2003, pp. 169-170) and at the same time have high values of fire extinguishing concentration: C _area = 0.78 kg / m ² , C _volume ≥0.52 kg / m ³ .

The known module of powder fire extinguishing (RF Patent No. 2283154, publ. March 20, 2006, bulletin No. 25 of September 10, 2006), the closest in terms of features to the claimed fire extinguishing device and chosen by us for the prototype. The module contains a normatively collapsing case with a lid and a charge of a thermosetting fire-extinguishing powder composition, inside of which there is a gas generator with an initiator connected to an alarm system to force its initiation. The mass ratio of the thermally responsive fire extinguishing gas generating charge is determined by the formula:

,

,

where M _GGS - mass of gas generating composition, kg;

Q _mountains - heat of combustion of the GHS, kJ / kg;

M _OPS - the mass of thermally responsive OPS, kg;

E is the activation energy of the OPS, kJ / kg.

The disadvantages of the prototype device are its low extinguishing efficiency of LVH and GF and the inability to suppress the deflagration combustion of gas-air and dust-air mixtures due to the fact that it does not provide the formation of formed gas-dispersed flows. When a prototype module with a mass of 5.06 kg is detonated, the outer casing is destroyed and the products of combustion of the gas-generating composition and the reaction products of the thermosetting fire-extinguishing composition (TROPS) are released into the atmosphere, forming a spherical (when undermining in the air) or hemispherical (when undermining on the ground) aerosol cloud with area S = 20 m ² , diameter Ǿ = 5 m (see the description of the patent prototype No. 2283154).

During the explosion suppression of air-gas and gas-dust mixtures, the length of the protected zone should be at least 20 m with a propagation velocity of the front of the deflagration combustion of the methane-air mixture (MVS) of 100 m / s and an induction time of 0.05 s, after which the combustion passes into the explosion. The prototype device provides for 0.02 s the creation of a cloud with a diameter of Ǿ = 5 m, i.e. the flow velocity is: R: τ = 2.5 m: 0.02 s = 125 m / s. Those. the passage time of a one-way gas-dispersed flow from the module with the protection of 20 m of the tunnel will be 20 m: 125 m / s = 0.16 s, while after 0.05 s the deflagration combustion of the MVS will go into explosion (detonation).

It follows that in order to solve the problem, it is necessary to increase the feed rate of the flux of extinguishing agent OTV, at least 3.2 times, i.e. up to 400 m / s.

The objective of the present invention is to develop a method of gas-dispersed quenching and a device for its implementation, which allows to increase the efficiency of extinguishing flammable liquids, combustible materials and to suppress the deflagration combustion of air-gas and gas-dust mixtures.

The problem is solved by the proposed method of gas dispersed fire fighting and a device for its implementation, combined by one inventive concept.

To obtain the above result, in the inventive method of gas-dispersed quenching of flammable liquids, gas liquids and suppression of deflagration combustion of gas-air and gas-dust formations, a gas-dispersed flow of extinguishing agent (OTV) is supplied from a modular device to a fire zone, while the inhibiting dispersed phase with a juvenile surface and a phlegmatized dispersive dispersive the flow is formed from a supercritical fluid formed by the following actions:

- initiate an exothermic process using a pyrocartridge with an electric start in a thermochemical charge placed in a reaction chamber connected through an exhaust valve and a damper chamber and an inlet valve with an internal cavity of a gas cylinder with a gas liquefied phlegmatizer and / or combustion inhibitor;

- open the exhaust valve of the reaction chamber and organize the outflow of the reaction products of the thermochemical charge into the damper chamber;

- upon reaching a pressure in the damper chamber exceeding the pressure of saturated vapor of the liquefied gas in the gas cylinder, open the inlet valve on the cylinder and organize the bubbling of the reaction products of the thermochemical charge through the liquefied gas phlegmatizer and / or combustion inhibitor until the supercritical pressure and temperature values necessary for the transfer are reached formed mixture of extinguishing agents into a supercritical fluid;

- in parallel with the initiation of a thermochemical charge, a pyroelement is initiated on the locking-starting device;

- open the above locking and starting device, through a nozzle or nozzles

organize the outflow of a gas-dispersed flow of extinguishing agent with a supercritical speed into the fire zone.

The thermochemical charge in the proposed method is made of smoky gun (DRP) or pyroxylin (PP) or ballistic powder, or mixed solid rocket fuel (STRT), or a pyrotechnic composition (PS), or explosive (BB), or any combination of them .

Carbon dioxide or sulfur hexafluoride, or “SF6 gas”, or fluoro-chichones are taken as a liquefied gas phlegmatizer of combustion, and bromine and / or iodine chladones are taken as liquefied inhibitors.

The method is carried out using a device - a module of gas-dispersed fire extinguishing, containing a gas cylinder with a charge of a gas liquefied phlegmatizer and / or a combustion inhibitor and a reaction chamber with a thermochemical charge and a pyro cartridge with an electric start unit connected to a fire alarm system for forcing a thermochemical charge, moreover, for the passage of reaction products, the reaction chamber through its exhaust valve, damper chamber and inlet valve is connected to the inside the ileus of the liquefied gas cylinder, characterized in that the shut-off and start device on the gas cylinder is made in the form of at least a two-layer wad pressed into the siphon body, the lower part of the wad in contact with the contents of the gas cylinder made of hot-melt foil or plate and the upper outer part of the wad is made of an elastic pyroelement with an electric igniter connected to the ignition unit of the igniter, with the ratio of the masses of the thermochemical charge and liquefied gas:

where M _TKhZ - mass of thermochemical charge, kg,

Q _rea - reaction heat kJ / kg,

M _{compressed gas} - the mass of liquefied gas, kg,

With _p - the heat capacity of the liquefied gas, kJ / kg • K,

T _cr - critical temperature for the taken substance, K.

T _min - the minimum allowable operating temperature of the device, K.

Comparison of the proposed method with the prototype and other methods of powder, gas powder and gas dispersed fire extinguishing, as well as the claimed device with the prototype module of powder fire extinguishing, identified in the prior art, showed that there is no known technical solution to the problem in which the proposed combination of features would take place.

The physical essence of this method and device for its implementation consists in transferring a substance with a phlegmatizing or inhibitory effect on combustion processes to a new aggregate state - supercritical fluid (GFR), which in its physical properties cannot be assigned to previously known aggregate states (solid , liquid, gaseous, plasma), as the above fluid, having a physical density comparable to a liquid, has a fluidity and membrane permeability identical to gases. At the same time, GFR have an exceptional dissolving power, far superior to organic solvents.

These properties of GFR are widely used in the West in industrialized countries in various industries and economies, such as in the dry cleaning of clothes and materials, the dissolution of polymers, organic and inorganic salts, for example, chlorides, bromides, metal iodides, for the impregnation of polymers, extraction of medicinal and food substances from plant materials. When withdrawing GFR solutions from a critical state, i.e. when the temperature and pressure decrease below critical, the solvent (GFR) goes into a gaseous state, and the dissolved or extracted substance is transformed into an aerosol of the so-called condensation type with submicron and micron particle sizes. The most common for these purposes (more than 90% of all GFR) is carbon dioxide CO ₂ , which is the cheapest, economically pure and effective fluid. Water can also be converted to GFR, but this requires very high pressures (220 atm) and temperatures (≥340 ° C), which is energetically disadvantageous, especially compared with carbon dioxide (T _cr = 31.05 ° C, P _cr = 72.8 atm).

In patent materials, the Internet, and scientific and technical literature, we did not find references to the use of GFR for extinguishing fires.

The above gives reason to consider the proposed method and device as inventive.

The proposed device for implementing the method of gas-dispersed quenching is illustrated in the graphic image shown in the drawing.

The device contains a gas cylinder 5 with a nozzle 1 and a locking and starting device 2 with a puff wad pressed in the siphon case 3 - “elastic pyroelement / metal foil” with an electric start unit 4, as well as a liquefied gas phlegmatizer 6 with a reaction chamber 7, equipped therein thermochemical charge 8, with a pyro cartridge 9, with an electric starter assembly 10, as well as an exhaust valve 12, which allows the reaction products of TX3 to pass from the reaction chamber 7 through the damper chamber 13 and the inlet valve 11 into the cavity of the gas cylinder 5 with liquefied gas phlegmatizer and / or combustion inhibitor 6.

The proposed device for implementing the method of gas dispersed fire extinguishing works as follows. When an electrical impulse is applied to the electric start unit of the igniter 9 and the electric start and wad 4, the elastic pyroelement wad and the igniter 9 are simultaneously ignited, which excites the chemical reaction TKhZ 8. When TKhZ 8 is burned, the combustion products through the exhaust valve 12 flow into the damper chamber 13, whence they reach therein a pressure exceeding the saturated vapor pressure of the liquefied phlegmatizer and / or inhibitor 6 in the cavity of the gas cylinder 5, through the exhaust valve or valves 11 are bubbled in the medium of liquefied gas 6 it into a supercritical state, or in the supercritical fluid.

At the same time, along with the combustion of the thermo-chemical agent, the elastic pyroelement of the puff wad burns up, and the heat released during the combustion of the elastic pyroelement melts the metal, for example, foil, opening the outlet for the formed GFR through the ZPU and nozzle into the fire zone.

According to the invention, a device based on a one-liter gas cylinder was made for testing. The device diagram is shown in the drawing.

A mass of liquefied carbon dioxide phlegmatizer was taken 0.7 kg. As TCP, we used DRP with a heat of combustion of 2.76 kJ / g.

The mass of DRP is calculated by the formula (1) for the operating temperature range (-50 ° С) - (+ 50 °):

The heat capacity of liquid CO ₂ is equal to C _p = 2.75 kJ / kg • deg

The “layered” wad in the ZPU consisted of a compressed elastic EPT current pyroheater and aluminum foil S = 0.3 mm.

The tests were carried out in a pipe ⌀ = 1.13 m and a length of 10 m; V _Tr = 10 m ³ .

The ends of the pipe on both sides to half the diameter are closed by flanges. 466 liters of water were poured into the chamber and 233 liters of AI-80 gasoline were placed on top.

A 1-liter module according to the invention was installed from one end of the camera, and an electronic photorecorder from the opposite.

Simultaneously with the ignition of gasoline vapor in the chamber, voltage was applied to the module and the photo recorder. After 0.021 s, an aerosol cloud was recorded at the end of the pipe opposite the module and the source was extinguished. Extinguishing of gasoline was also carried out 15 seconds after it was ignited. Extinction quenching occurred after 0.025 s.

Thus, the velocity of the gas-dispersed jet was 435-476 m / s, the extinguishing concentration was:

The inventive method and device surpass the prototype in flow rate by ≈3.6 times in volumetric extinguishing concentration in

At the same time, a new effect is achieved - the suppression of deflagration combustion.

List of sources used

1. RF patent No. 2036674, published 09.06.95, "Method for producing a fire extinguishing jet."

2. RF application No. 95105555, published November 20, 1996, “Method of extinguishing fires”.

3. RF patent No. 2083243, published July 10, 1997, "Method of extinguishing fires."

4. RF application No. 2005125096, published on 02.20.07, “Method and device for extinguishing flammable and combustible liquids (LVH GZh) in tanks”.

5. RF patent No. 221508, published December 10, 2004, “Method for extinguishing a fire in tanks”.

6. RF patent №2258549, published on 08/20/05, "Method of extinguishing a fire in a tank and device for its implementation."

7. RF patent No. 2243014, published December 27, 2004, "Method of extinguishing forest fires."

8. RF patent No. 2135236, published August 27, 1999, “A method for volumetric fire extinguishing and a device for its implementation”.

9. RF patent No. 2134604, published on 08/20/99, "Method of extinguishing a fire and composition for its implementation."

10. RF patent №2115450, published on July 20, 1998, “A method for volumetric fire extinguishing and a device for its implementation”.

11. Application No. PCT / RU 2006/000167, published under No. WO 2007/117168 A1, 10/18/2007 with a priority of 06/22/04.

Claims (4)

1. A method of gas-dispersed quenching of flammable liquids, combustible materials and suppression of deflagration combustion of gas-dust and gas-air mixtures by supplying a gas-dispersed flow of extinguishing agent from a modular device to a fire zone, characterized in that the inhibiting dispersed phase with a juvenile surface and the phlegmatizing dispersed dispersive medium supercritical fluid formed by the following actions:
initiate an exothermic process using a pyrocartridge with an electric start in a thermochemical charge placed in a reaction chamber connected through an exhaust valve and a damper chamber and an inlet valve with an internal cavity of a gas cylinder with a liquefied phlegmatizer and / or combustion inhibitor;
open the exhaust valve of the reaction chamber and organize the outflow of the reaction products of the thermochemical charge into the damper chamber;
upon reaching a pressure in the damper chamber exceeding the pressure of saturated vapors of the liquefied gas in the gas cylinder, open the inlet valve on the cylinder and organize the bubbling of the reaction products of the thermochemical charge through the gas liquefied phlegmatizer and / or combustion inhibitor until the supercritical pressure and temperature values necessary to transfer the formed mixtures of extinguishing agents in a supercritical fluid;
in parallel with the initiation of a thermochemical charge, a pyroelement is initiated on the locking-starting device;
open the above-mentioned locking and starting device, through the nozzle or nozzles organize the expiration of the gas-dispersed flow of extinguishing agent with supercritical speed into the fire zone. 2. The method of gas-dispersed quenching according to claim 1, characterized in that carbon dioxide, or sulfur hexafluoride, or SF6 gas, or fluoro-chichones are used as the gas liquefied phlegmatizer, and bromine or iodocholones are used as the gas liquefied inhibitors. 3. A device for extinguishing flammable liquids, combustible materials, suppressing deflagration combustion of dust and gas-air mixtures, containing a gas cylinder with a nozzle, a shut-off and starting device and with a charge of a gas liquefied phlegmatizer and / or inhibitor, as well as a reaction chamber equipped inside this cylinder thermochemical charge and a squib with an electric start unit connected to a fire alarm system to force the initiation of a thermochemical charge, and for ode of reaction products, the reaction chamber through its exhaust valve, damper chamber and inlet valve is connected to the internal cavity of the liquefied gas cylinder, characterized in that the locking and starting device on the gas cylinder is made in the form of at least a two-layer wad pressed into the siphon body, moreover, the lower part of the wad in contact with the contents of the gas cylinder is made of hot-melt foil or plate, and the upper outer part of the wad is made of an elastic pyroelement with an electric igniter, annym engine starting with the cutter assembly, at a ratio by weight of the charge and thermochemical liquefied gas:

where M _TKhZ - mass of thermochemical charge, kg;
Q _rea - reaction heat kJ / kg;
M _{compressed gas} - the mass of liquefied gas, kg;
With _p - the heat capacity of the liquefied gas, kJ / kg · degK;
T _cr - critical temperature for the taken substance, city K;
T _min - the minimum allowable operating temperature of the device, city K. 4. The device according to claim 3, characterized in that the thermochemical charge is made of smoke, or pyroxylin, or ballistic powder, or mixed solid fuel, or from a pyrotechnic composition, or from an industrial explosive, or from a mixture of the above components.

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