RU2179047C2 - Volumetric fire-extinguishing apparatus - Google Patents

Abstract

FIELD: fire-fighting equipment. SUBSTANCE: apparatus is made in the form of thermochemical paraaerosol generator, which may be used for volumetric extinguishing in closed and partially enclosed spaces, as well as for localizing burning processes on open areas. Apparatus has combustion chamber with solid and /or liquid, and/or gaseous fuel and igniter, fire extinguishing liquid supply source, reaction chamber arranged behind combustion chamber in housing, mixing chamber with sprayer collector connected to fire-extinguishing liquid supply source, fire-extinguishing liquid overheating chamber and set of nozzles. Apparatus is further equipped with fire-extinguishant generator or gaseous combustion retardant generator positioned in overheating chamber, which is connected at its one side with mixing chamber through baffle-type separator and at its other side with aerosol nozzle unit through receiver. Gaseous combustion retardant is of thermochemical composition. Solid fuel is formed as compressed air foam mixture of powdered magnesium and/or aluminum, and/or alloy of mentioned substances with oxygen-, or fluorine- and/or chlorine-containing oxidizer and specific additive, for example binder and/or combustion catalyst, with metal:oxidizer:specific additive ratio being 10- 40:10-30:1-5, correspondingly. Thermochemical composition is mechanical mixture and/or alloy of ammonium nitrate and ammonium phosphate, and/or ammonium perchlorate, and/or ammonium phosphate, and/or carbonate of amide (carbamide) or compound based on red phosphor, thermal mixture and combustible. EFFECT: increased fire- fighting capacity by reduced consumption of fire-extinguishing substance and improved combustion retarding properties of fire-extinguishant. 3 cl, 2 dwg

Description

 The invention relates to water-aerosol extinguishing means, which is a steam-aerosol generator that can be used both for volumetric fire extinguishing in closed volumes, semi-closed volumes, and for localization of burning in open areas. Fire extinguishing in enclosed, semi-enclosed volumes, as well as localization of fire in open areas, occurs due to the rapid (fraction of a second) overheating and evaporation of the extinguishing fluid in a steam aerosol generator, for example water, at elevated pressure while the water vapor is saturated with a gaseous or aerosol combustion inhibitor generated by the composition inside the steam-aerosol generator, and the release of the resulting steam-aerosol mixture using the proposed device in the combustion zone.

 Known installations, devices, means, systems and methods for spraying liquid coolant for water, steam and water quenching with superheated water (1-8).

The disadvantages of water spraying devices are the high specific consumption (up to 900 l / m ² ) and the quenching time (≈60 min) of fuels and lubricants and flammable liquids (1), which is explained by the fact that a mechanically dispersed extinguishing liquid forms a coarse-dispersed sedimentation-unstable aerosol, particles which do not have time to evaporate in the plasma zone.

Steam extinguishing is effective, but requires large energy costs, since the extinguishing vapor concentration is 35% with a minimum intensity of not less than 0.05 kg / m ³ • s, i.e. to eliminate a fire in a room of 100 m ^3, it is necessary to transfer 21 kg of water into steam in at least 4 seconds (2).

Extinguishing with superheated water is more efficient, but all devices known from (3.5) require preheating of the extinguishing liquid (water) or the pressure created in the vessel by the extinguishing liquid due to overheating of the liquid from heat in the fire source. At the same time, for all the above-mentioned disadvantages of devices for producing superheated water, they lose several times to aerosol means (fire extinguishing aerosol generators) using solid fuel thermochemical compositions whose fire extinguishing concentration is 0.040-0.10 kg / m ³ depending on fire load.

The main disadvantage of fire extinguishing aerosol generators is their increased fire hazard due to the presence of a high-temperature torch of combustion products, which are a fire extinguishing agent. The disadvantages of fire extinguishing aerosol generators should also include the limitation in the class of extinguishing fires, since they do not extinguish class A ₁ fires, i.e. burning of solids accompanied by decay, as well as their low efficiency for local extinguishing of all classes of fires.

 The closest in purpose and combination of features is a device for volumetric fire extinguishing, containing a combustion chamber with an igniter, a fire extinguishing fluid supply source, a reaction chamber placed sequentially in the housing behind the combustion chamber, a mixing chamber with a nozzle manifold connected to a fire extinguishing fluid supply source, and a chamber for overheating the extinguishing fluid (9).

 The manifold with nozzles is connected by means of a pressure pipe blocked by a membrane with a container for a fire extinguishing liquid containing a gas generator, the nozzle is removable and installed on the free end of the overheating chamber, and a pressure ignition system with a thermochemical composition is installed on the pressure pipe, for which the fire extinguishing agent is overheated liquids use a mixture of aluminum and / or magnesium powders or their alloy with sodium or potassium nitrate and an organic binder in the ratio metal: oxides body: binder (30-40) :( 6-19) :( 1-4), respectively.

 As a reagent for overheating a fire extinguishing liquid in the reaction chamber, water or aqueous solutions of sodium, potassium, ammonium or a mixture thereof in a ratio by weight of thermochemical composition: water or aqueous solutions of 1: 1.2-1: 5.0 is used, and the mass ratio of thermochemical composition and extinguishing fluid in the overheating chamber is 1: 2-5.

The disadvantage of this known device is its low efficiency for volume extinguishing due to the low dispersion of the extinguishing agent S _frequent. ≅50 ... 100 microns and low inhibitory ability of active centers of the flame by particles of aerosol formed in the flame. The flow rate of the extinguishing agent in water for the generator during volumetric extinguishing is 0.2-0.5 kg / m ³ .

 The objective of the invention is to provide a device for volumetric fire extinguishing, providing a technical result, consisting in increasing the efficiency of fire fighting by reducing the consumption of extinguishing agent while increasing the inhibitory properties of the latter.

 This technical result in a device for volumetric fire extinguishing, containing a combustion chamber with an igniter, a fire extinguishing fluid supply source, a reaction chamber arranged sequentially in the housing behind the combustion chamber, a mixing chamber with a nozzle manifold connected to a fire extinguishing fluid supply source, and a fire extinguishing fluid overheating chamber , is achieved by the fact that it further comprises a fire extinguishing aerosol generator or a gaseous combustion inhibitor with a thermochemical composition installed in the chambers overheating and gas-aerosol nozzle unit, wherein the superheat chamber is connected on the one hand through zhalyuzny separator with the mixing chamber and on the other hand via the receiver with gas and aerosol nozzle unit and the combustion chamber comprises a solid and / or liquid and / or gaseous fuel.

 Solid fuel is a mechanical mixture of magnesium and / or aluminum powders and / or their alloy with an oxygen, fluorine and / or chlorine-containing oxidizing agent and a target additive, for example, a binder and / or combustion catalyst in the ratio metal: oxidizer: target additive (10- 40) :( 10-34) :( 1-5) respectively.

 The thermochemical composition is a mechanical mixture and / or an alloy of ammonium nitrate with ammonium phosphate and / or perchloric acid and / or sulfate and / or carbonic amide (urea) or a composition based on red phosphorus, thermal mixture and fuel.

 In FIG. 1 shows a steam aerosol generator with a solid fuel unit; in FIG. 2 - a combustion chamber with gaseous and liquid fuel.

 The positions in FIG. 1 indicate: 1 - a container of solid fuel, 2 - a block of solid fuel, 3 - a combustion chamber, 4 - an igniter, 5 - shock-prick mechanism, 6 - a capsule-igniter, 7 - igniter composition, 8 - a burning diaphragm, 9 - igniter device nozzles, 10 - divider, 11 - chipper, 12 - extinguishing liquid supply pipe, 13 - extinguishing liquid supply channels, 14 - reaction chamber with nozzle block, 15 - mixing chamber nozzles, 16 - mixing chamber nozzle block, 17 - pipeline overheating chamber injector block, 18 - mixing chamber, 19 - louvered separator of the condensed phase of the combustion products, 20 - nozzle block of the overheating chamber, 21 - generator of a fire extinguishing aerosol or gaseous combustion inhibitor, 22 - receiver of gas and vapor, 23 - perforated tube, 24 - aerosol forming or gas generating composition, 25 - chamber combustion fluid, 26 - gas aerosol receiver, 27 - aerosol nozzle block, 28 - water aerosol nozzle block, 29 - perforated cover of the gas aerosol generator.

 The positions in FIG. 2 designate: 30 - a pipeline for supplying a gaseous oxidizer, 31 - a pipeline for supplying a gaseous fuel, 32 - a combustion chamber, 33 - a swirler, 34 - an ignition device, 35 - a nozzle manifold for liquid fuel, 36 - a pipeline for supplying liquid fuel.

 The principle of operation of the solid fuel vapor-aerosol generator shown in FIG. 1, next.

Из корпуса генератора 21 через перфорированную трубку 23 и крышку 29 в газоаэрозольный ресивер 26 поступает смесь фосфорного ангидрида, паров воды и газообразный азот. Фосфорный ангидрид мгновенно реагирует с парами воды с тепловыделением и образованием 0.7625 кг 55,6% ортофосфорной кислоты, имеющей температуру кипения 117^oC. Пары ортофосфорной кислоты, газообразный азот и парогаз, поступающий из ресивера 22, смешиваются в ресивере 26 и под давлением через сопла 27 выбрасываются в атмосферу, образуя устойчивый туман ортофосфорной кислоты с дисперсностью d_ср≅0,5 мкм.
Таким образом, тушение пожара происходит за счет следующих факторов
1. Срыв пламени с горящей поверхности газодинамической струей.Upon receipt of a fire signal from the supply source system, extinguishing fluid through the pipe 12 enters the annular cavity I and II. The increase in pressure in the cavity triggers the shock-pricking mechanism 5, which actuates the igniter capsule 6 and the igniter composition 7. The igniter device 4 ignites the solid fuel blocks 2 and the channel of the burning diaphragm 8 through the nozzles 9. The combustion products of the solid fuel blocks are dispersed from the charge surface into the combustion chamber 3, where with the help of a divider 10 and a chipper 11 through the flammable channel of the diaphragm 8 they enter the reaction chamber 14, where secondary exothermic processes occur the action of vapors of unreacted fuel with water, as a result of which the temperature of the combustion products rises by approximately 1000 ^o C and becomes in the range of 2500-3000 ^o C. Simultaneously with the start of the shock-pricking mechanism 5 through the cavity 1 and channels 13, a fire extinguishing liquid (water) is supplied to the nozzle the blocks of the reaction chamber 14, the mixing chamber 16, and the overheating chamber 20. The jets of the extinguishing liquid from the block 14, hitting the bump 11, create a shroud (curtain) in the reaction chamber 14. High-temperature combustion products from the chamber 14 enter PL 15, in which the flow of combustion products is equalized, and in the mixing chamber 18, the mixture of combustion products with the extinguishing liquid is homogenized and partially evaporates. A homogenized mixture of water and its vapors, gaseous and condensed combustion products from the mixing chamber enters the condensate louver 19, after which part of the gas enters the receiver 22, and part with the condensate passes into the overheating chamber 25 of the extinguishing fluid, where from the pipe 17 through the nozzle unit 20 extinguishing liquid is sprayed in an amount that ensures its evaporation and / or overheating to a temperature of 170-180 ^o C at a pressure in the overheating chamber of 0.6-1 MPa. The superheated steam-water (vapor-liquid) mixture enters the water-aerosol nozzle block 28, where it accelerates to a speed of 400-600 m / s and is released into the atmosphere. Superheated drops of water (extinguishing liquid) under the influence of internal partial pressure are crushed (as if “explode”), forming an aerosol with a dispersion d _cf ≅ 500 ... 100 microns.
The separated vapor gas from the receiver 22, passing through the perforated tube 23, heats the composition 24 located in the aerosol (gas) generator 21 to the temperature of the onset of aerosol formation reactions, for example, to the reaction between ammonium nitrate and ammonium phosphate, in equal mass fractions, according to the following equation according to thermodynamic calculations:

A mixture of phosphoric anhydride, water vapor and nitrogen gas enters from the generator housing 21 through a perforated tube 23 and a cover 29 into a gas-aerosol receiver 26. Phosphoric anhydride instantly reacts with water vapor with heat generation and the formation of 0.7625 kg of 55.6% orthophosphoric acid having a boiling point of 117 ^o C. Vapors of orthophosphoric acid, nitrogen gas and steam coming from receiver 22 are mixed in receiver 26 and under pressure through nozzles 27 are emitted into the atmosphere, forming a stable fog of phosphoric acid with a dispersion d _cf ≅ 0.5 μm.
Thus, fire fighting is due to the following factors
1. Disruption of a flame from a burning surface by a gas-dynamic jet.

 2. Cooling of the flame due to heat extraction for the evaporation of the extinguishing fluid.

 3. Reducing the oxygen concentration in the fire zone due to the formation of water vapor from the water aerosol and the supply of steam and gas from the steam aerosol generator.

 4. Homogeneous chemical inhibition of combustion due to the vapor of salts, acids and gaseous inhibitors.

 5. Heterogeneous inhibition of active flame centers on a salt or acid aerosol with a juvenile surface with uncompensated chemical bonds.

 6. Isolation of a solid smoldering surface with solutions of phosphate salts or phosphoric acid.

 The principle of operation of the steam-aerosol generator on liquid and / or gaseous fuel is similar to solid fuel, except that when using, for example, kerosene or propane, the maximum temperature is reached not in the reaction chamber, but in the combustion chamber. But, given the higher calorific value of the above fuels, the end result is identical.

The small size, autonomy, high vapor and aerosol performance and safety of the generator, its relatively low cost and high operational efficiency allow it to be used in various industries and agriculture. In particular, a steam aerosol generator can be used as:
- a means of volumetric fire extinguishing of all combustible substances that do not react with water, including smoldering materials, gunpowder and explosives in warehouses, industrial premises, boats, oil basements, ventilation shafts, etc.);
- a means of local fire extinguishing at oil, gas and petrochemical industry facilities;
- a means of preventing the explosion of dust and gas mixtures in mines and other dusty rooms;
- an aerosol generator for creating shielding curtains and thermal protection of technological equipment at objects of storage of flammable liquids and fuels and lubricants in case of fires;
- a means for the deposition of smoke in the fire;
- a means to neutralize aggressive gas and aerosol formations in extreme force majeure circumstances;
- a means for steaming, cleaning, neutralizing the internal surfaces of containers (tanks, cisterns, tanks);
- a tool for removing and modifying rust of internal metal surfaces of various containers;
- for sanitary insecticidal and bactericidal treatment of livestock farms, ship holds, etc .;
- for steam treatment of wood and cellulosic materials with flame retardants in order to give them fire resistance;
- jet engine for planes, scooters and other high-speed sports vessels;
- a means of emergency braking of moving watercraft;
- a universal pipe cleaner from mechanical and chemical deposits;
- A reactor for aerosol heterogeneous synthesis of new substances.

The high power of the steam aerosol generator (from 10 ⁴ kW to 10 ⁸ kW per 1 kg of fuel) allows you to translate various solutions into the steam aerosol state with a capacity of from tenths to tens of kilograms of liquid per second (i.e. from several hundred to tens of thousands of liters of water steam per second). Moreover, the chemical composition of the liquid converted to steam is critical only for reasons of safety, ecology and chemical resistance of the generator material.

The use of a steam aerosol generator as a means of steam aerosol extinguishing provides advantages over all known extinguishing agents in part:
- before freon systems: 1-2 orders of magnitude lower cost and environmental cleanliness;
- in front of deluge and sprinkler systems: an order of magnitude lower consumption of extinguishing fluid, small size, autonomy, high efficiency, lower cost;
- fire extinguishing aerosol generators: versatility (extinguishing fires of classes A, B, C), safety;
- extinguishing powder: reducing the cost of the extinguishing agent, warranty periods of storage, reliability.

Comparative tests of the generator — the type and the proposed generator for extinguishing fires of classes A, B, C in a room with a volume of 50 m ³ showed 3-5 times higher efficiency of the latter according to the criterion of the amount of extinguishing agent to protect 1 m ^{3 of the} room. On average, the extinguishing agent consumption for a known generator was 18 kg (16 kg of water and 2 kg of solid fuel), for the generator of the invention, 4.0 kg (0.5 kg of solid fuel, 2 kg of water and 1.5 kg of ammophos mixture with ammonium nitrate).

Sources of information
1. Baratov A.N. and Korolchenko A.Ya. Directory. Fire safety of substances and materials and means of extinguishing them. - M., Chemistry, 1990, v. 1, p. 104.

 2. Kazakov M.V., Petrov II, Reut V.Ch. Means and methods of extinguishing the flame of flammable liquids. - M., Stroyizdat, 1977.

 3. RU 2058168 C1, 04/20/1996.

 4. RU 2067465 C1, 10.10.1996.

 5. RU 2087170 C1, 08.20.1997.

 6. RU 2050866 C1, 12/27/1995.

 7. SU 1837907 A3, 08.30.1993.

 8. SU 161484 A1, 12/23/1990.

 9. RU 2090229 C1, 09/20/1997.

Claims (3)

 1. A device for volumetric fire extinguishing, comprising a combustion chamber with an igniter, a fire extinguishing fluid supply source, a reaction chamber placed sequentially in the housing behind the combustion chamber, a mixing chamber with a nozzle manifold connected to a fire extinguishing fluid supply source, and a fire extinguishing fluid overheating chamber, characterized in the fact that it further comprises a fire extinguishing aerosol generator or a gaseous combustion inhibitor with a thermochemical composition installed in the overheating chamber, and a gas aerosol a nozzle block, wherein the overheating chamber is connected on one side through a louvre separator to the mixing chamber and, on the other hand, through a receiver with a gas-aerosol nozzle block, and the combustion chamber contains solid and / or liquid and / or gaseous fuel.  2. The device according to p. 1, characterized in that the solid fuel is a mixture of powders of magnesium and / or aluminum and / or their alloy with oxygen, fluorine and / or chlorine-containing oxidizing agent and the target additive, for example a binder and / or combustion catalyst , in the ratio metal: oxidizing agent: target additive 10-40: 10-34: 1-5, respectively.  3. The device according to one of paragraphs. 1 and 2, characterized in that the thermochemical composition is a mixture and / or an alloy of ammonium nitrate with ammonium phosphate and / or perchloric acid and / or sulfate and / or carbonic amide (urea) or a thermochemical composition is a composition based on red phosphorus , thermal mixture and fuel.

Images