RU2200044C2 - Method for providing fire-suppressing concentration of inert diluent (versions) - Google Patents

Abstract

FIELD: fire-fighting equipment. SUBSTANCE: method involves providing volume fire-suppression by means of automatic fire suppressing units, movable volume gas fire-suppressing units and movable local fire-suppressing units, as well as portable units for suppressing of classes A, B, C, D, E fires; generating nitrogen and simultaneously removing oxygen from space of room to be protected from fire. Such units may be used in enterprises of automobile transport industry, in mechanical engineering enterprises for creating inert medium, in chemical industry for increasing efficiency of ammonia synthesis units. EFFECT: wider operational capabilities and increased efficiency. 3 cl, 3 dwg

Description

 The invention relates to a method of gas fire extinguishing inside and outside the premises associated with the use of flammable liquids, at various electrical installations under voltage, the premises of radio relay stations, transmitting and receiving radio centers, transmitting radio stations with transmitters with a capacity of 150 kW, stationary space communication stations with a transmitting device power of more than 1 kW, automatic telephone exchange, where they install switching equipment of quasi-electronic and electronic types together with a computer used as a control reporting complex, maintenance-free rooms, battery rooms, rooms for storing and issuing unique publications, manuscripts and other documents of special value, in banks, pawnshops, television towers, sealed submarine compartments, in aircraft, gas pipelines. In addition, the invention relates to the field of cryogenic engineering, in particular, to use the effect of superconductivity in radio electronics (volume resonators, circuits, computer nodes), in quantum technology, in the field of communication to create small-sized designs of radio frequency cables, communication cables, in mechanical engineering, for intensification of metal cutting in the energy sector.

 Known methods of volumetric gas fire extinguishing using gaseous nitrogen, carbon dioxide, argon, water vapor and combustion inhibitors (AN Baratov. EN Ivanov. Fire extinguishing at the enterprises of the chemical, petrochemical and oil refining industries. Chemistry, Moscow, 1971).

 The closest technical solution for the considered group of inventions is a method of quenching with gaseous nitrogen, disclosed in the description of the invention to the application 94015637, cl. A 62 C 2/00, publ. 12/10/1995.

 Moreover, with the first object of this group of inventions, this method contains the following common features: in the combustion zone, a fire extinguishing concentration of nitrogen is created by its continuous generation. However, when implementing the specified known method, a decrease in the oxygen concentration occurs only by supplying nitrogen to the combustion zone without removing oxygen from the room.

 To obtain a fire extinguishing concentration of an inert diluent-nitrogen with the simultaneous removal of oxygen from the room, a volumetric fire extinguishing method is used, in which a fire extinguishing concentration of nitrogen is generated in the combustion zone by continuous generation and according to the present invention, oxygen is removed from the volume of the protected room, while nitrogen generation and oxygen removal carry out gas separation plants with nitrogen intake from the volume of the protected premises, from the volumes of neighboring rooms, outside or in combination fences, moreover, to enhance the fire extinguishing effect, the nitrogen is cooled or liquefied and fed into the combustion zone in a sprayed form, and in maintenance-free rooms create excessive pressure of the gas mixture with a reduced oxygen content of 5 vol.% or less, not causing combustion.

 With the second object of the invention, the indicated closest method of volumetric fire extinguishing contains the following common features: the creation of a fire extinguishing concentration of an inert diluent-nitrogen by its continuous generation and concentration.

 When implementing this object of the invention, to obtain a fire extinguishing concentration of an inert diluent-nitrogen with the simultaneous removal of oxygen from the room, a volumetric fire extinguishing method is used, including creating a fire extinguishing concentration of an inert diluent-nitrogen by continuously generating and concentrating it, and a fire extinguishing concentration of inert diluent-nitrogen is created up to 99.5 vol.% gas separation plants with oxygen removal per volume of the protected space, while the generation and concentration of nitrogen suschestvlyayut gas separation installations which operate separately, simultaneously or sequentially, with higher values for extinguishing effect with the increasing fire nitrogen supplied to the combustion zone is cooled or liquefied and atomized within the scope of the protected space.

 To implement the claimed group of inventions, a gas separation unit, the operation of which is based on various physical principles, is installed indoors or outdoors.

 When air is supplied by a compressor (vacuum pump) to a gas separation unit, oxygen-nitrogen gas separation occurs, while oxygen is removed from the room and this ensures a continuous increase in the extinguishing nitrogen concentration inside the room, and to enhance the extinguishing effect, the nitrogen is cooled or liquefied by turbine expanders. In addition to the process, nitrogen concentrations provide continuous generation of nitrogen into the room.

 A method of obtaining a fire extinguishing concentration of an inert diluent of nitrogen can be applied when transporting gas (methane, propane and other combustible gases), lowering its concentration to explosion and fireproof nitrogen, and at the point of consumption, nitrogen is separated by gas separation.

The invented method (and its variant) is characterized in that:
environmentally friendly, ozone-depleting effect is zero;
ensures the continuity of the process of generation and concentration of inert diluent-nitrogen (the release time of existing gas compositions is not more than 60 seconds);
- reduces the risk of increased pressure inside the protected room (due to the initial removal of oxygen from the room to 5 or less volume percent), which poses a threat to the strength of the protected structure;
- reduces the likelihood of an exothermic reaction of the synthesis of nitrogen oxides, increasing the temperature inside the burning room;
- it is possible to enhance the fire extinguishing effect of traditional inert diluents (carbon dioxide, argon, water vapor, chladones, as well as aerosol fire extinguishing generators);
- there is no possibility of repeated fires characteristic of traditional fire extinguishing systems, due to the continuous generation of an inert diluent-nitrogen, its concentration in the volume of the room (when installing a gas separation device with a compressor inside the room) and the removal of oxygen from the room;
- provides visibility during the evacuation of people from the premises during the operation of the installation for oxygen removal and nitrogen generation;
- provides extinguishing inside the burning equipment due to the penetration of molecular nitrogen through equipment leaks and oxygen removal, it allows, especially in the concentration mode (oxygen removal) to extinguish the substances emitting oxygen in the combustion process;
- provides for the possibility of working in modes of concentration, nitrogen generation, or the operation of both modes simultaneously;
- there is the possibility of redistributing the oxygen concentration inside several rooms (submarine compartments, aircraft) by extracting it from the volume of the burning room and redistributing it in non-burning rooms;
- in order to reduce the possibility of fire, it is possible to maintain premises without maintenance personnel (maintenance-free facilities, granaries) under excessive nitrogen pressure;
- non-toxic, dielectric, does not cause corrosion, provides extinguishing of various electrical installations under voltage;
- it is possible to obtain not air-mechanical foam, but nitrogen-mechanical foam, which has great fire extinguishing potential;
- there is the possibility of increasing the fire extinguishing power due to the concentration, generation of nitrogen, and then its cooling by the compressor or cooling, liquefaction by a turboexpander with its subsequent spraying into the combustion zone;
- nitrogen liquefaction allows you to expand its fire extinguishing capabilities and use it to extinguish alkali metals, use it to protect small objects (closed electrical distribution devices, safes, cabinets, devices for various purposes) from fire, alcohol, acetone, and organo-silicon compounds;
- there is the possibility of extinguishing high-rise sealed structures (TV towers) regardless of the direction of spread of the fire;
- there is the possibility of modernizing existing fire extinguishing installations that use nitrogen to transport freons, powder and combined formulations through pipelines to the fire, with its subsequent use as the main fire extinguishing agent;
- there is the possibility of local extinguishing of fires of units and equipment with the inexpediency of extinguishing in the volume of the entire room.

 The invention is illustrated by drawings, in which Fig. 1 shows a schematic diagram of an automatic plant for generating and concentrating an inert diluent-nitrogen, Fig. 2 is a mobile plant for generating, concentrating and local fire fighting, in Fig. 1. 3 - portable installation for local fire fighting.

 The proposed scheme consists of the following elements: remote start devices for a gas fire extinguishing installation (UGP) - 1, 29; light annunciators - 2, 3, 16, 22; magnetic contacts - 4, 28; sound annunciators - 5, 23; gas separation membranes of preliminary gas separation - 6, 9, 19, 21; air filter - 7, 10, 18, 20; fire detectors - 8, 11, 14, 26, 27; distribution devices - 12, 17, 33, 36, 40, 41; nozzles for supplying nitrogen - 13, 15, 24, 25; control panel 30 (PKP); launching devices - 31, 32; pressure signaling devices - 34, 37; compressor (vacuum pump) - 38, 43, gas separation unit - 39, 47, station manifold - 35; turbo expanders - 44, 46; manual start devices - 48, 49; battery collector - 50; trunk pipelines - 51, 52; protected premises - A, B; fire extinguishing station premises - C.

An automatic installation for the generation and concentration of an inert diluent-nitrogen implements the considered fire extinguishing method as follows:
in the event of a fire in room "A", the control panel (PKP) 30 detects the operation of two fire detectors 26, 27 according to the "I" pattern, and then generates signals for: the inclusion of sirens, light 22, sound 23 in the room for personnel evacuation; turning off ventilation in the room; fire warning to the central monitoring console (shown by arrows); after a time delay for evacuation, the corresponding starting device 31 is turned on. The latter generates starting pulses for the switching devices of the corresponding direction 33, 17, 40 to turn on and turns on the compressor 38. Magnetic contact 28 is designed to turn off the automatic start of the installation.

 The compressor takes the air from room "A", while it is possible to preconcentrate nitrogen by installing gas separation membranes (devices) 19 installed in the room behind the air filters.

 To further concentrate the nitrogen in room A, the gas mixture is fed by compressor 38 to the gas separation device 39, where the nitrogen is finally enriched to 99.95 vol.%, After which the nitrogen through the manifold 50, through the station collector 35, enters main pipelines 51 through nozzles 24, 25 into the room, and oxygen is removed from the room into the environment or neighboring rooms (compartments of submarines, aircraft, underground objects). To enhance the extinguishing effect, the enriched nitrogen is cooled by a compressor 38 or cooled and liquefied by a turboexpander 46. For this purpose, a separate compressor and gas separation apparatus (not shown) can be used. Heat exchangers are not shown in the drawing.

 The nitrogen supply is recorded by the pressure switch 34, the signal of which is used to issue a notification ("Gas has gone") to the control panel 30 and to turn on the siren 16 ("Gas - do not enter") outside the protected room.

 Remote start-up of an automatic installation for generation and concentration is carried out by evacuated personnel using device 29. If automatic and remote start-up of the installation is not carried out due to a hardware failure, the duty personnel must go to room “C” and start the compressor 38 manually, open valves 33, 40 , 17.

 Compressor 43, gas separation device 47, and turboexpander 44 can be used in the mode of additional nitrogen generation in rooms "A" and "B" with air intake for subsequent gas separation from the environment or an adjacent room (compartment) or can be used as backup plants for generating and nitrogen concentration in rooms "A" and "B" (trunk pipelines for the nitrogen concentration mode are not shown in the drawing).

 An automatic gas extinguishing installation for the generation and concentration of nitrogen should be placed as close as possible to the object of protection or in the room itself. This will reduce the length of the pipelines and the response time of the installation (inertia).

 Figure 2 shows a mobile installation for the generation, concentration and local fire fighting.

 The installation consists of the following elements: pipeline 1; frame 2; pipeline 3, flexible sleeve 4, sleeve 5, compressor 6, pipeline 7, installation case 8, turbo expander 9, gas separation device 10, hose fastening lever 11, pressure gauge 12, valve 13, safety valve 14, extension 15, sprayer 16, flexible sleeve 17, dispensing valve 18.

 A mobile installation for generation, nitrogen concentration and local fire extinguishing works as follows.

 a) The mode of generation and concentration of nitrogen.

 The air of the room to be protected (78 vol.% Nitrogen and 20.9 vol.% Oxygen) is supplied by compressor 6 through an air filter (not shown) to a gas separation device 10, in which air is divided into two streams - penetrated through a membrane (enriched with oxygen) and not penetrated (nitrogen enriched) streams. The oxygen-rich gas mixture through pipeline 1, the flexible pipe 4 and the sleeve 5 are removed from the room, and the nitrogen-rich gas mixture through the valve 13 continuously enters the protected room (1st operating mode).

 The gas mixture enriched with nitrogen enters the turboexpander 9, where the nitrogen is cooled, liquefied, and through the valve 13 enters the room (2nd operating mode). A separate compressor and a gas separation device may be provided for the operation mode with a turboexpander.

 The air filter can be equipped with a gas separation membrane for pre-enrichment of the air with nitrogen.

 b) Local fire fighting mode.

 Identical to the mode of generation and concentration. In the local fire extinguishing mode, the valve (exhaust head) 13 is closed, and the valve 18 is open and nitrogen enters through the flexible sleeve 17, through the extension 15 to the sprayer 16.

 Figure 3 shows a portable installation for local fire extinguishing.

 The installation consists of the following elements: an air filter with a gas separation membrane 1, a battery 2, an electric motor 3, a gas mixture supercharger 4, a gas separation device 5, a cooler 6, a tip 7, a housing 8, a gas mask valve box or a breathing bag 9, a hose 10.

 A portable installation for local fire extinguishing works as follows.

 The air of the room to be protected with the help of the gas mixture supercharger 4, through the air filter 1 (can be equipped with a gas separation membrane) enters the gas separation device 5, where the air is divided into oxygen-nitrogen fractions. Nitrogen entering the secondary cooler 5 (the supercharger 4 (8) can serve as the primary cooler) is cooled and, through tip 7, enters the fire source. Oxygen after the gas separation process can be used in gas masks used in smoky rooms.

 An example implementation of the method.

For testing automatic plants for generation and concentration, a room with a volume of 280 cubic meters, a leak parameter of 0.06 m ^-1 , and a leak rate of 2.0 were used.

As combustible substances were used:
- wood, paper, textiles - fire subclass A;
- gasoline - a subclass of fire B-1;
- alcohol, methanol, glycerin - a subclass of fire B-2;
- propane, household gas, hydrogen - fire class C;
- textolite, phenoplast - subclass A-2;
- a burning electrical installation that is energized - class E.

To remove oxygen from the room (concentration mode), a compressor with a capacity of 8 m ³ / min was used. A compressor with a capacity of 5.0 m ³ / min was used to supply nitrogen to the protected room (generation mode). Anisotropic membranes made of PVTMS (polyvinyltrimethylsilane) were used as a gas separation membrane. They are a two-layer film, the lower layer of which is an anisotropic membrane, the upper layer is a film of a polymeric material based on polyurethanesiloxane, as well as its modernized versions of grades C-3.5A TU 6- 05-111-353-88; S-3,5 MTU 6-05-111-88. These membranes, which are the main element of gas separation plants, are highly resistant to temperature extremes during operation, insoluble in water, non-toxic, non-explosive.

The oxygen / nitrogen gas selectivity at 20 ^o C and a pressure drop of 0.1 MPa is not less than 130-160 l / m ² • h. Membranes can be used at air pressures up to 3.0 MPa. It is possible to use other gas separation devices, the action of which is based on various physical principles and which enrich the gas mixture to 99.95 vol.% With nitrogen.

The mobile installation was used to extinguish materials of subclasses A-1, B-1, B-2, E, class D in the mode of generation and concentration of nitrogen (volume fire extinguishing) in a room of 120 m ³ and local fire extinguishing. A portable gas fire extinguishing installation was used to extinguish burning electrical equipment, plastics (textolite, polyethylene), paper, methanol in the generation mode.

Claims (2)

 1. The method of volumetric fire extinguishing, in which a fire extinguishing concentration of nitrogen is created in the combustion zone by its continuous generation, characterized in that oxygen is removed from the volume of the protected space, while nitrogen is generated and oxygen is removed by gas separation units with nitrogen intake from the volume of the protected space, from volumes of adjacent rooms, outside or in fence combinations, moreover, to enhance the fire extinguishing effect, nitrogen is cooled or liquefied and fed into the combustion zone in a sprayed form, and in unattended x smokers and pressurized gas mixture having a reduced content of oxygen and 5 vol. % or less, not causing combustion.  2. A method of volumetric fire extinguishing, including the creation of a fire extinguishing concentration of an inert diluent - nitrogen by its continuous generation and concentration, characterized in that a fire extinguishing concentration of an inert diluent - nitrogen is created up to 99.5 vol. % gas separation plants with oxygen removal per volume of the space to be protected, while nitrogen generation and concentration are carried out by gas separation plants operating separately, simultaneously or sequentially, and to increase the power of the fire extinguishing effect as the fire intensifies, the nitrogen supplied to the combustion zone is cooled or liquefied and sprayed into the volume of the protected space.

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