JP3719565B2 - Fire extinguishing method and fire extinguishing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fire extinguishing method and a fire extinguishing apparatus, and more particularly, the present invention relates to a fire extinguishing method using a gas, in which a sufficient human evacuation time is ensured without impeding fire fighting activities, The present invention relates to a fire extinguishing method and a fire extinguishing apparatus that are advantageous in terms of cost.
[0002]
[Prior art]
There are several places where the use of liquids should be avoided as a fire extinguishing means. For example, a museum, a computer room, a semiconductor manufacturing factory, a food storage, etc. These places can be devastated by spraying and contacting a large amount of liquid during a fire, even if the fire is small.
[0003]
From such a viewpoint, extinguishing a fire with a gas without using a liquid is now being performed. For example, gas fire extinguishing with a halogen-based gas such as perfluoroalkanes or carbon dioxide is typical, and many techniques related to this are proposed (Japanese Patent Laid-Open No. 7-39603, Japanese Patent Publication No. 1-33686). Gazette, Japanese Patent Publication No. 8-17832, Japanese Patent Laid-Open No. 7-237907, etc.).
[0004]
However, the use of a halogen-based gas has a problem on the global environment, and the use of carbon dioxide has the following problems. Ie:
(1) Carbon dioxide is difficult to diffuse in the air and easily accumulates downward, so that the fire extinguishing efficiency is poor.
(2) Carbon dioxide is highly reactive and may cause harmful carbon monoxide.
[0005]
Therefore, a technique using nitrogen, which occupies approximately 80% of the atmosphere, as a fire extinguishing gas is also known. Nitrogen occupies most of the atmosphere and therefore has almost the same density as the air density, easily diffuses into the air, and has low reactivity. In the event of a fire, nitrogen is oxidized to nitrogen oxides, but the amount is negligible and has little effect on the human body. For these reasons, expectations for using nitrogen gas for fire extinguishing are increasing.
[0006]
[Problems to be solved by the invention]
However, in the nitrogen gas extinguishing currently in practical use, it is necessary to install a plurality of nitrogen gas pressurization containers (nitrogen cylinders) in the vicinity of the target fire extinguishing area, and a space for that purpose must be provided. The costs associated with the purchase and storage of nitrogen cylinders are not negligible. In addition, nitrogen gas ejected from a nitrogen cylinder at the time of a fire can drastically reduce the oxygen concentration in the fire extinguishing area, and therefore strictly control the oxygen concentration in the fire extinguishing area assuming the presence of humans in the fire extinguishing area. There is a need to do. Furthermore, if a large amount of nitrogen gas is blown into the fire extinguishing area after a person has evacuated, the oxygen in the fire extinguishing area may rapidly decrease and hinder fire fighting activities.
[0007]
Accordingly, it is an object of the present invention to provide a fire extinguishing method and a fire extinguishing apparatus that are sufficiently advantageous in terms of the size and cost of facilities without sufficiently hindering the fire fighting activities in fire extinguishing using gas. is there.
[0008]
[Means for Solving the Problems]
As a result of intensive studies, the present inventor has been able to solve the conventional problems as described above.
That is, according to the present invention, when a fire occurs in a relatively sealed fire extinguishing area, the air in the fire extinguishing area is sucked, the air is compressed, and the compressed air is contacted with a permeable membrane having excellent oxygen permeability. In the fire extinguishing method in which the compressed air is separated into oxygen-enriched air and nitrogen-enriched air, and the obtained nitrogen-enriched air is returned to the fire-extinguishing area, human presence is confirmed in the fire-extinguishing area. The pressure of the compressed air entering the permeable membrane is reduced , the oxygen concentration in the fire extinguishing area is maintained at 12 to 15%, and when no human is present in the fire extinguishing area, the permeable membrane increasing the entrance pressure of the compressed air to the extinguishing wherein said oxygen concentration in the suppression area, human presence in said suppression area is characterized Rukoto is lower than the oxygen concentration to be maintained when it is confirmed Is to provide.
[0010]
Furthermore, the present invention provides a compressor for compressing air in a fire extinguishing zone, a permeable membrane having excellent oxygen permeability capable of separating the obtained compressed air into oxygen-enriched air and nitrogen-enriched air, and the permeation a circulation path for circulating the air in the suppression area through the membrane, and a human body detecting device or surveillance cameras to verify the presence of a person in the suppression area, presence of a person has been confirmed in the suppression area In this case, when the compressor is operated at a low speed to reduce the pressure of the compressed air entering the permeable membrane , the oxygen concentration in the fire extinguishing area is maintained at 12 to 15%, and no human is present in the fire extinguishing area. Provides a fire extinguishing device that raises the pressure of compressed air entering the permeable membrane and lowers the oxygen concentration in the fire extinguishing area below the oxygen concentration maintained when human presence is confirmed in the fire extinguishing area What to do That.
[0011]
Furthermore, the present invention provides the fire extinguishing apparatus, wherein the permeable membrane is formed from a uniform membrane or a composite membrane made of an organic polymer.
[0012]
Further, the present invention provides the fire extinguishing apparatus, wherein the permeable membrane has a cylindrical shape having a hollow portion, which is a single unit, and is a module type in which a large number of the units are assembled.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is intended for extinguishing a relatively sealed space (extinguishing area). When a fire occurs, the air in the extinguishing area is sucked to convert the air into nitrogen-enriched air, and the fire is extinguished. By returning to the area, the oxygen concentration in the fire extinguishing area gradually decreases, so that the fire can be extinguished slowly. According to such fire extinguishing, people in the fire extinguishing area can evacuate quickly with sufficient oxygen concentration at the initial extinguishing stage, and fire fighting activities are not hindered. At a subsequent stage, the oxygen concentration in the fire extinguishing area further decreases, and the fire moves in the direction of extinguishing. In a further stage, the oxygen concentration in the fire extinguishing zone is reduced to a concentration at which it is no longer possible to burn the material and complete digestion is achieved.
[0014]
First, the fire extinguishing method of the present invention will be described.
In the event of a fire, the air in the fire extinguishing area is first sucked and compressed by a compressor or the like. The compressed air is brought into contact with a permeable membrane having excellent oxygen permeability. The permeable membrane separates compressed air into oxygen-enriched air and nitrogen-enriched air. This type of permeable membrane is already well known, and organic polymers such as polydimethylsiloxane or derivatives thereof, polyamide, polyimide, polyamideimide, polyacetylene, polyethylene, polypropylene, polyethylene terephthalate, polysulfone, polyethersulfone, parisin, polythiol Rubbers such as polycarbonate and polybutadiene, polystyrene and their fluorine, chlorine and bromine substituted products, derivatives and copolymers thereof, or composite membranes thereof. It is a highly permeable membrane with a structure in which the above-mentioned uniform organic polymer membrane such as polydimethylsiloxane is impregnated on a porous membrane made of molecules. For example, polydimethylsiloxane is impregnated on a porous body of polysulfone. Is transparent Although sexual suitable are often used, or a combination other than this. Of these, polydimethylsiloxane or a derivative thereof, polyacetylene, and the like are suitable as the uniform film. In addition, what is marketed can use what is marketed, for example, the prism separator of Monsanto, the nitrogen gas generator of Ube Industries, etc. are mentioned.
[0015]
In order to efficiently obtain nitrogen-enriched air from compressed air, the permeable membrane has a cylindrical shape with a diameter of about 1 to 10 μm, and a hollow portion is provided as one unit. For example, about 10,000 to 100,000 units are assembled. A so-called module type is preferable. Such modules are generally known. In this case, a module is produced so that compressed air flows into the hollow part of the unit. FIG. 3 shows an example of the unit. The permeable membrane 21 has a cylindrical shape, a hollow portion 22 is formed, and the unit 20 is configured.
[0016]
FIG. 2 schematically shows the module. The module 2 is an assembly of about 10,000 to 100,000 units 20 inside. When compressed air is introduced from one end of the module 2, the air that has passed through the permeable membrane 21 of the unit 20 is oxygen. The air that has become enriched air and has passed through the hollow portion 22 becomes nitrogen-enriched air, which can be separated.
Polysulfone, polyethersulfone, polycarbonate, polyimide, and polyamide used as hollow fiber materials are called heat-resistant polymers and can withstand high temperatures and high pressures. The gas permeation phenomenon in the polymer membrane is a dissolution / diffusion mechanism, and the gas permeation coefficient in the membrane increases remarkably as the temperature rises. For this reason, normal temperature may be sufficient as the gas introduce | transduced into a module, but preferable temperature is 30-100 degreeC. If the temperature is too high, deterioration of the polymer material is promoted, which is not preferable.
Even in a device that does not control the temperature of the introduced gas by a heat exchanger or the like, the temperature in the room rises due to heat generated by a fire, so the temperature of the introduced air naturally rises, the amount of nitrogen permeation increases, and digestion is promoted. Although the temperature dependence of the transmission coefficient varies depending on the material, it generally depends on the activation energy. Therefore, when the temperature rises from 30 ° C. to 100 ° C., the transmission coefficient increases about 5 to 10 times.
[0017]
The nitrogen-enriched air thus obtained is returned again into the fire extinguishing zone, and the oxygen concentration in the fire extinguishing zone is reduced. The oxygen concentration in the fire extinguishing area should be reduced as follows.
Fire extinguishing early stage-oxygen concentration around 15%. At this concentration, humans can evacuate quickly from the fire-extinguishing area.
Fire extinguishing stage-oxygen concentration 10-15%. At this concentration, the fire goes to extinguishment. Even if the oxygen concentration is 10 to 15%, humans can perform activities such as evacuation and fire extinguishing. Therefore, there is no hindrance to the activities of the fire brigade after the human evacuation (in the past, it was thought that humans would become cyanosis or died at an oxygen concentration of 15%, but now the oxygen concentration is 10-15. % Have not been confirmed to pose a danger to human life).
Final stage-Oxygen concentration 0-10%. At this oxygen concentration, combustion of the material is not possible.
[0018]
The oxygen concentration in the fire extinguishing zone can be controlled by the permeation pressure of the permeable membrane, for example, compressed air at the inlet of the module. When the pressure of entry of compressed air at the module inlet is high, the oxygen concentration in the fire extinguishing zone decreases rapidly. Conversely, when the pressure of entry is low, a gentle decrease in oxygen concentration is obtained.
[0019]
Next, the fire extinguishing apparatus of the present invention will be described. FIG. 1 is a view for explaining a fire extinguishing apparatus of the present invention.
The apparatus 1 of the present invention is provided with a circulation path 3 in which air in the fire extinguishing area 40 can be taken in an arbitrary place in the fire extinguishing area 40. From here, the air in the fire extinguishing zone 40 is taken in by means of compressing air such as the compressor 5. The compressed air further contacts a permeable membrane having excellent oxygen permeability that separates oxygen-enriched air and nitrogen-enriched air. According to the embodiment of FIG. 1, a module 2 is installed. The nitrogen-enriched air exhausted from the module 2 is returned to the fire extinguishing zone 40 via the circulation path 3.
[0020]
Further, an example of the operation of the apparatus of the present invention will be described on the assumption that a fire has occurred.
The fire detector 6 detects a fire that has occurred in the fire extinguishing area 40 and sends a fire signal to the receiver 7. The shutoff valves 8 and 11 installed in the circulation path 3 are opened by a signal from the receiver 7. The compressor 5 is started and the air in the fire extinguishing area 40 is sucked and compressed. The oxygen concentration in the fire extinguishing area 40 is confirmed by the installed oxygen concentration meter 9. The compressed air is then passed through module 2 to obtain nitrogen enriched air. When the presence of a person in the fire extinguishing zone 40 is confirmed by a human body detector or a monitoring camera, the compressor 5 is operated at a low speed, the pressure of the compressed air entering the module 2 is lowered, and the oxygen concentration in the fire extinguishing zone 40 is reduced. Maintain about 12-15%. When it is confirmed that no person is present in the fire extinguishing area 40, the pressure of the compressed air entering the module 2 is increased, and the oxygen concentration in the fire extinguishing area 40 is further decreased. The pressure of the nitrogen-enriched air is returned to the fire extinguishing zone 40 while being controlled by the pressure gauge 12 and the oxygen concentration by the oximeter 13.
[0021]
[Action]
The present invention extinguishes a relatively sealed fire extinguishing area with nitrogen gas, and one of the advantages is that the oxygen concentration in the extinguishing area can be gradually reduced. As described above, the oxygen in the fire extinguishing area is sufficient for quick evacuation at the initial fire extinguishing stage.
Moreover, since nitrogen gas is almost the same as the air density, it is easy to diffuse, and conventionally, it is useful for extinguishing a complex shaped article that does not reach liquid. Places where the present invention can be suitably implemented include PET bottle rack warehouses, general offices, cable tunnels, etc., in addition to the above-mentioned museums, computer rooms, semiconductor manufacturing factories, and food storages. Especially in a fire in a PET bottle rack warehouse, the amount of heat generated by plastic is large, and when it gets hot, it may show a fire form similar to a flammable liquid. Is relatively difficult. In addition, in order to obtain nitrogen-enriched air, it is only necessary to remove oxygen from the air, so there is an advantage that the work amount is small. Furthermore, if the apparatus of the present invention is applied, harmful components such as CO ₂ , CO, NOx, SOx, soot, HCN, and HCl generated in a fire can be removed by the permeable membrane.
[0022]
【The invention's effect】
According to the present invention, there is provided a fire extinguishing method and a fire extinguishing apparatus that are sufficiently advantageous in terms of the size and cost of facilities without sufficiently hindering the fire fighting activity in fire extinguishing using gas. .
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a fire extinguishing apparatus according to the present invention.
FIG. 2 is a schematic diagram for explaining a module;
FIG. 3 is a perspective view of a cylindrical unit having a hollow portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Apparatus 2 of this invention Module 3 Circulation path 5 Compressor 6 Fire detector 7 Receiver 8, 11 Shut-off valve 9, 13 Oxygen concentration meter 12 Pressure gauge 20 Unit 21 Permeation membrane 22 Hollow part

Claims (4)

When a fire occurs in a relatively sealed fire extinguishing area, the air in the fire extinguishing area is sucked, the air is compressed, and the compressed air is brought into contact with a permeable membrane having excellent oxygen permeability. In a fire extinguishing method in which the oxygen-enriched air and nitrogen-enriched air are separated, and the obtained nitrogen-enriched air is returned to the fire-extinguishing area.
When human presence is confirmed in the fire-extinguishing area, the pressure of the compressed air entering the permeable membrane is reduced , the oxygen concentration in the fire-extinguishing area is maintained at 12 to 15% , When no human is present, the pressure of the compressed air entering the permeable membrane is increased, and the oxygen concentration in the fire extinguishing area is changed to the oxygen concentration maintained when human existence is confirmed in the fire extinguishing area. extinguishing wherein the Rukoto more reduced. A compressor that compresses air in the fire extinguishing zone, a permeable membrane that can separate the obtained compressed air into oxygen-enriched air and nitrogen-enriched air, and the permeable membrane through the permeable membrane. a circulation path for circulating the air in the suppression area, and a human body detecting device or surveillance cameras to verify the presence of a person in the suppression area, said compressor when the presence of human the suppression area is confirmed reducing the entry pressure of the compressed air to the permeable membrane at low speed operation, to maintain the oxygen concentration of the suppression area 12 to 15% above when a person is not present in the suppression area said by the compressor A fire extinguishing apparatus that raises the pressure of the compressed air entering the permeable membrane and lowers the oxygen concentration in the fire extinguishing area below the oxygen concentration maintained when human presence is confirmed in the fire extinguishing area . The fire extinguishing apparatus according to claim 2 , wherein the permeable film is formed of a uniform film or a composite film made of an organic polymer. The fire extinguishing apparatus according to claim 2 or 3 , wherein the permeable membrane has a cylindrical shape having a hollow portion, which is a unit type in which a single unit is formed.

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