JPH05177008A - Fire extinguishing method of cable in tunnel and foam fire rxtinguishfr - Google Patents

Abstract

PURPOSE:To extinguish a fire at the connection section or a cross section of cables in a tunnel. CONSTITUTION:The periphery of the cable connection section 2 or a cross section of cables 1 is enveloped with a meshy fireproof fabric 8, and foam is discharged in the surrounded space to extinguish a fire when the fire breaks out. The fire can be extinguished in a short time. The space can be saved when a foam fire extinguisher is used, and no pump is required. Since form envelops the flame, smoke is temporarily sealed when the fire breaks out, and workers can evacuate to a safe location during this time. The periphery of the connection section 2 or the cross section of the cables 1 is enveloped with the fireproof fabric 8 of an insulator, troubles due to arcs can be prevented, and scattered objects by the blast and explosion when arcs occur can be mitigated. The fireproof fabric 8 is flexible unlike a metallic meshy body, the periphery of the insertion section of the cables 1 has excellent adhesion to the surrounded space, and the rocking of the cables 1 can be absorbed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extinguishing a fire at a connecting portion or a crossing portion of an underground cable in a cave, and a foam extinguishing apparatus.

[0002]

2. Description of the Related Art When a fire occurs in an underground cable laid in a cave, a ground fault or the like may be induced and a serious disaster may occur. It is considered that the cable fire is most likely to occur at the connecting part or the crossing part of the cable. Therefore, at present, an appropriate fire extinguisher is installed around this connection part to take the initial fire extinguishing system, but the conventional fire extinguishing method is to open the valve interlocking with the appropriate heat sensing device and use the pump to surround the connection part. Is sprayed with water.

[0003]

However, in such a method, when the installation location becomes a long distance, various restrictions occur due to a decrease in water pressure due to the relationship of the rating of the pump, etc.
As it is, there is a possibility that the intended purpose may not be achieved. To deal with this, it is necessary to install a large pump and corresponding equipment and space, or to install a large tank for storing fire extinguishing water at regular intervals, which causes problems in securing cost and space. is there.

[0004]

In order to solve such a problem, the present invention has the following constitution. That is, according to the first aspect of the present invention, the area around the connecting portion or the crossing portion of the cable is preliminarily surrounded by a net-like fireproof cloth, and when a fire occurs in the connecting portion or the crossing portion, it is surrounded by the fireproof cloth. It is intended to extinguish a cable fire by releasing bubbles into the open space. For this fire resistant cloth,
A fire resistant fabric composed of aramid fibers is suitable. From the viewpoint of both ventilation and maintenance of bubbles, it is desirable that the coarse density of the fire-resistant cloth be about 10 mesh.

According to the second aspect of the present invention, the outer periphery of the cable connecting portion or the crossing portion in the cave is covered directly with a loose cloth covered with a heat-resistant and high-strength fiber, and the end of the mesh cloth is covered. It is fixed to the outer circumference of the connecting part or the crossing part, and when a fire occurs in the connecting part or the crossing part, bubbles are emitted between the inner circumference of the mesh cloth and the outer circumference of the connecting part or the crossing part to cause a cable fire. To extinguish a fire. This heat-resistant and high-strength fiber is made by twisting aramid fiber and silica fiber together, and has high strength and sufficient resistance to high temperatures.

According to a third aspect of the present invention, a plurality of mesh cloths made of heat-resistant and high-strength fiber are directly arranged on the outer periphery of the connecting portion or the crossing portion of the cable in the cave so as to be lined up along the connecting portion or the crossing portion. The end portion of each of these mesh cloths is fixed to the outer periphery of the connecting portion or the crossing portion, and when a fire occurs in the connecting portion or the crossing portion, the inner periphery of each of these mesh cloths and the connecting portion or It is intended to extinguish a cable fire by discharging bubbles between the outer periphery of the crossing portion.

Further, as a highly foaming type fire extinguisher suitable for use in such a fire extinguishing method, in a device for blowing a chemical to a mesh by a compressed gas to generate foam for extinguishing a fire, the cross section of the mesh (net A fire-extinguishing device is proposed in claim 4, characterized in that the cross section perpendicular to the plane of the body is made substantially corrugated. The reticulate body here refers to a punched metal, a wire mesh, or the like having many small holes.

Further, in the fire extinguisher having such a structure, a high foam extinguisher which is characterized in that the peripheral portions of a large number of holes in the net-like body are bulged to the side of the spraying source.

Further, in a fire extinguisher for generating foam for extinguishing a fire, a low foam fire extinguisher is proposed, characterized in that a chemical, water and compressed nitrogen gas are mixed and enclosed.

[0010]

According to the first aspect, the fire in the space surrounded by the fireproof cloth is extinguished by filling the space with bubbles and covering the flame. Also, when an explosion occurs, the blast is dispersed and released to the outside through the net-like fireproof cloth, the fireproof cloth is not broken, and the foam is securely held and extinguished.

According to the second aspect, when a fire occurs in the cable connecting portion or the crossing portion covered with the net-like cloth made of heat-resistant and high-strength fiber, this is detected and the inner circumference of the net-like cloth and the connecting portion or Bubbles are discharged between the outer periphery of the intersection and the bubbles are filled while inflating the mesh cloth. This extinguishes the flame by covering the flame. In the case of an explosion or the like, the operation is the same as that of the above-mentioned claim 1. According to claim 3, for each net cloth covering the outer circumference of the cable connecting portion or the crossing portion where a fire has occurred, this is detected and between the inner circumference of the net cloth and the outer circumference of the connecting portion or the crossing portion. The bubbles are released, and the bubbles are filled while inflating the mesh cloth. This allows the flame to be covered more quickly. In the case of an explosion or the like, the operation is the same as that of the above-mentioned claim 1.

According to the fourth aspect, since the cross section of the net-like body is substantially corrugated, the surface area, that is, the number of small holes is increased as compared with the conventional planar net-like body. According to the fifth aspect, since the peripheral portion of the hole is raised toward the spraying source, the retention time and the adhesion time of the drug to the mesh body are longer than in the conventional type. Also, the amount of drug that covers the pores increases. Therefore, bubbles can be efficiently generated, the generated bubbles are not easily broken, and the bubble maintaining time is long.

According to the sixth aspect, when a fire is detected, the valve of the low foam extinguisher is opened and the foam is immediately discharged. At that time, unlike the above high foam extinguisher, it is not necessary to suck in air.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view of the first embodiment of the present invention,
2 is a side view, and FIG. 3 is a sectional view taken along the line AA in FIG. 1, in which 1 is a cable, 2 is a cable connection body, and 3
Is the inner wall of the cave and 4 is the floor of the cave. In general, a cable 1 to be laid in a cave is laid so that an appropriate receiving metal fitting 6 is horizontally fixed to a metal plate 5 supported on the inner wall of the cave and the cable is placed on the receiving metal 6.

Using these uprights 5, an appropriate frame body 7 made of a channel material or an angle material is installed so as to surround the cable connection body 2, and the frame body 7 has a fire resistance of 10 mesh. A cloth 8 is attached. The frame body 7 is formed by sequentially fixing rectangular frames made of channel material or angle material to the metal stand 5. Further, substantially cone-shaped penetration portion covering bodies 9 and 10 made of refractory fibers are fixed to the penetration portions of the cable 1 at both ends in the longitudinal direction. A fire extinguisher mounting body 11 is fixed to the upright 5 on the outer side of the frame body 7 on the inner side wall 3 side, and a high foam extinguisher 12 is fixedly installed to the fire extinguisher mounting body 11. A duct 13 is provided in the blowout part of the high foam extinguisher 12.
The outlet of the duct 13 is directed to an opening formed in the wire mesh panel 14 installed on the inner wall 3 side of the cavern 7 in the substantially central portion of the frame 7.

Next, the details of the high foam extinguisher 12 will be described with reference to FIGS. 4, 5 and 6, the main body of which is a substantially cylindrical body, and the outer peripheral wall 15 has a double structure and is hollow. The part is partitioned by an annular partition 16 to form annular compartments 17 and 18, respectively. The compartment 17 is filled with compressed nitrogen gas and a chemical, and the compartment 18 is filled with high-pressure nitrogen gas and water. 19 is both compartments 17,
It is a pressure equalizing valve provided in a bypass connecting 18 and by opening the pressure equalizing valve 19, the water and the medicine are kept at the same pressure and are mixed at an appropriate mixing ratio.

An automatic mixing valve 20 is provided at the center of the main body of the high foam extinguisher 12, and the chemicals and water stored in the compartments 17 and 18 are mixed here, and the nozzle is passed through a constant flow valve 21. It is jetted from 22 toward the foamed net 23 stretched at one end opening of the main body by the pressure of nitrogen gas. Then, when passing through the foam net 23, the surrounding air is entrained, and a large amount of foam for extinguishing fire is discharged as shown in FIG. The automatic mixing valve 20 is automatically opened / closed by a signal from a heat-sensitive detection head 24 provided at an appropriate position on the frame 7.

As shown in FIGS. 4 and 5, the foam net 23 is made of punching metal having a wavy cross section, and the number of holes 25 is increased as the surface area is increased. It was adopted. In addition, the peripheral portions of the holes 25 formed in large numbers are raised toward the spraying source (on the nozzle 22 side) as shown in FIG. By raising in this way, it is possible to efficiently generate high-quality foam for fire extinguishing.

The main equipment for the first embodiment is constructed as described above, and when a fire occurs in the cable connecting body 2, the heat is detected by the detecting head 24, and the operation signal is immediately mixed. It is sent to valve 20 to open it. Then, a large amount of bubbles are ejected from the foam net 23 and discharged from the duct 13 into the space surrounded by the fire resistant cloth 8 to extinguish the fire. In addition, unlike the case of simply injecting bubbles toward a fire, bubbles can be discharged into a certain compartment to fill the same, so that the fire can be extinguished in an extremely short time. At this time, since the refractory cloth 8 is in the form of a net, air easily escapes when the bubbles occupy the space and fills the space.
By adopting a mesh grade, bubbles will not leak out.

In a normal state, since the net-like fireproof cloth 8 surrounds the cable connector 2, it has good ventilation,
It does not impair the cooling required for underground cables.
Although the underground high-voltage cable swings back and forth, and right and left, since the fireproof cloth 8 is highly flexible, it is easy to attach the penetrating portion covering bodies 9 and 10 as in the embodiment, and the cable 1 It is easy to secure the adhesion around the penetration part of the cable 1 and the cable 1
However, there is no problem even if it swings in that way. Moreover, since the arc failure is prevented by adopting the fire resistant cloth 8, and the blast at the time of the arc and the scattered matter due to the explosion can be alleviated,
Damage to personnel and various equipment can be suppressed.

The high-foam extinguishing system 12 used in the first embodiment is a so-called integral type in which nitrogen gas, chemicals and water are set in one body, but it is possible to make it more compact and to have a large amount. In order to supply the nitrogen gas, the chemical, and the water, the separate high foam extinguisher 31 like the second embodiment shown in FIG. 7 can be provided. In this type, a cylinder 32 containing a medicine and water is separately provided, installed on the floor surface 4 of the strait, and fixed to the frame by a member such as an automatic mixing valve, a nozzle and a foam net. .. Therefore, if the space between the inner wall 3 of the cave and the upright 5 cannot be taken large,
This is effective when preparing a large amount of nitrogen gas, chemicals, and water.

Next, FIG. 8 is an explanatory plan view of a third embodiment of the present invention, FIG. 9 is an explanatory side view of the same, and FIG. 10 is B in FIG.
It is a B-line sectional view, and the cable 1, the cable connection body 2, the inner side wall 3 of the cave, the inner floor surface 4 of the cave, the upright 5 and the metal fitting 6 have the same configuration as in the first embodiment. In the case of this embodiment, the frame 7 of the first embodiment is not provided, and two substantially rectangular mesh cloths 33 made of heat-resistant and high-strength fiber formed by twisting aramid fibers and silica fibers are prepared. Cloth 33
Are arranged in the longitudinal direction of the outer circumference of the cable connecting body 2, and they are directly covered on the outer circumference of the cable connecting body 2 and covered, and each end of each net-like cloth 33 is tied with a string 34. In this way, the outer periphery of the cable connection body 2 is covered with the two mesh cloths 33.

Further, two low foam fire extinguishers 35 for supplying bubbles to the two mesh cloths 33 are supported by an appropriate support material such as the metal upright 5, and each of the low foam fire extinguishers 35 led out. The other end of the pipe 36 is branched into three to form a branch pipe 36a, and the ends of the branch pipes 36a are arranged at intervals along the outer circumference of the cable connector 2, and a detection head is provided at the end of each branch pipe 36a. 37 is provided. Then, the respective detection heads 37 are put inside and the outer periphery of the cable connection body 2 is covered with the respective net-like cloths 33.

In the case of the third embodiment, when a fire occurs at the cable connecting body 2, the heat is detected by the nearest detecting head 37 and the valve of the corresponding low foam extinguisher 35 is immediately activated. Open, and a large amount of bubbles will appear on each sensing head 37.
Release from. Then, the foam fills the outer peripheral space of the cable connecting body 2 surrounded by the mesh cloth 33, swells the mesh cloth 33 and is discharged between the inner circumference of the mesh cloth 33 and the outer circumference of the cable connecting body 2 to extinguish the fire. It

In the third embodiment, the cable connecting body 2
The two mesh cloths 33 are arranged side by side in the longitudinal direction of the cable connecting body 2 on the outer periphery of the above, but not limited to this, the mesh cloth 33 is enlarged and the cable connecting body 2 is covered with one mesh cloth 33. Is also good. Although the cable connecting body 2 has been described in any of the above embodiments, the present invention is not limited to this, and the same method can be applied to the cable crossing portion.

[0026]

According to the first aspect of the present invention, the fire is extinguished by discharging bubbles into the pre-enclosed space, so that the fire of the connection portion of the cable in the cavern can be extinguished quickly and effectively.
Moreover, it is easy to install equipment and instruments for that purpose. By using a high-foaming device, space can be saved and a pump etc. is unnecessary.

Further, since the bubbles envelop the flame in this manner, smoke generated during a fire can be temporarily contained, and an operator can be blamed in a safe place during this period. Further, in the sound of explosion caused by a blast during a fire, the fire-resistant cloth and bubbles in the space serve to muffle sound, and the fire-resistant cloth can prevent scattered objects. Further, since the insulating fire-resistant cloth surrounds the connecting portion of the cable, it is possible to prevent an obstacle due to the arc, and further, to disperse the blast at the time of the arc generation and to escape the blast from the mesh of the fire-resistant cloth. In addition, since it is rich in flexibility unlike a metal net such as a wire net, it has excellent adhesion of the cable penetration portion to the enclosed space and can follow the swing of the cable.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the cable connecting body or the crossing portion is directly covered with the net cloth made of the heat-resistant and high-strength fiber in advance, so that the equipment and the equipment are provided. Is simpler, has better workability, is not bulky, and is suitable for narrow caverns. In addition, the heat-resistant and high-strength fiber has high strength and can withstand high heat, can retain bubbles inside, and reliably assists fire extinguishing.

According to the invention of claim 3, in addition to the effect of claim 1, the net-like cloth made of heat-resistant and high-strength fiber covering the cable connection body or the crossing portion is divided into a plurality of parts. The space filled with bubbles is small, and therefore, the fire starting point on the outer circumference of the cable connector or the intersection can be wrapped with bubbles more quickly.

According to the fourth aspect, since the cross section of the net-like body is substantially corrugated, the surface area, that is, the number of small holes is increased as compared with the conventional planar net-like body, and as a result, a larger amount of bubbles are generated. The fire can be extinguished quickly. Also, the entire device can be made more compact than the conventional type, and is suitable for installation in a limited space such as in a cave.

According to the fifth aspect, it is possible to generate bubbles more efficiently while having the same effect as the second aspect. Moreover, the bubbles that are generated are of good quality and are not easily broken, and the bubbles are maintained for a long time. Therefore, an optimum foam can be provided for extinguishing a fire.

According to claim 6, the low foam fire extinguisher is extremely simple in construction, does not require any other power source, and can be extremely easily installed anywhere, and therefore saves space. When generating bubbles, the high-foam fire extinguisher must suck in clean air, but in the event of a fire it may also inhale smoke, in which case it may not be possible to generate enough bubbles. In the foam fire extinguisher, since it is not necessary to suck air when bubbles are generated, the bubbles can be surely generated even when smoke is generated.

[Brief description of drawings]

FIG. 1 is an explanatory plan view showing a state in which a cable connection body is surrounded by a fireproof cloth body in a first embodiment.

FIG. 2 is a side view showing a state in which the cable connector is surrounded by a fire resistant cloth in the first embodiment.

3 is a cross-sectional view taken along the line AA in FIG.

FIG. 4 is a side sectional view of the high foam extinguisher according to the first embodiment in a normal state.

FIG. 5 is a vertical cross-sectional view of the foam net according to the first embodiment.

FIG. 6 is a side sectional view of the high foam extinguisher according to the first embodiment in a foamed state.

FIG. 7 is an explanatory view from the axial direction in the second embodiment in which the high foam fire extinguisher is a separate type.

FIG. 8 is an explanatory plan view showing a state in which a cable connector is surrounded by a fire resistant cloth in the third embodiment.

FIG. 9 is a side view showing a state in which a cable connector is surrounded by a fire resistant cloth in the third embodiment.

10 is a sectional view taken along line BB in FIG.

[Explanation of symbols]

 1 Cable 2 Cable Connection 3 Cave Side Wall 4 Cave Floor 6 Receiving Metal 7 Frame 8 Fire Resistant Cloth 9 Penetration Cover 10 Penetration Cover 12 High Foam Fire Extinguisher 13 Duct 22 Nozzle 23 Foam Net 25 Hole 33 Mesh Cloth 35 Low foam fire extinguisher 36 Pipe 37 Detection head

Claims (6)

[Claims] 1. A cable-like connecting portion or a crossing portion in a cave is surrounded by a net-like fireproof cloth in advance, and when a fire occurs at the connecting portion, the space is surrounded by the fireproof cloth. A method of extinguishing a cable, characterized by releasing bubbles. 2. Loosely covering the outer periphery of a connecting portion or a crossing portion of a cable in a cave with a net cloth made of heat-resistant and high-strength fiber, and fixing the end portion of the net cloth to the outer periphery of the connecting portion or the crossing portion. A fire extinguishing method for a cable, characterized in that, when a fire occurs in the connecting portion or the crossing portion, bubbles are discharged between the inner periphery of the mesh cloth and the outer periphery of the connecting portion or the crossing portion. 3. A plurality of reticulated cloths made of heat-resistant and high-strength fibers are arranged directly along the outer periphery of a connecting portion or a crossing portion of a cable in a cave and are loosely arranged along the connecting portion or the crossing portion to cover them. The end of each net-like cloth is fixed to the outer periphery of the connecting portion or the crossover portion, and when a fire occurs at the connecting portion or the crossover portion, the inner periphery of each of these netlike cloths and the outer periphery of the connecting portion or the crossover portion are A method of extinguishing a cable, characterized in that bubbles are released during the period. 4. A high foam extinguisher device, wherein a cross section of the mesh body is formed into a substantially corrugated shape in a device for generating a foam for extinguishing a fire by spraying a chemical agent or the like onto a mesh body by a compressed gas. 5. The method according to claim 4, wherein the peripheral portions of the large number of holes in the net-like body are raised toward the spraying source.
High foam fire extinguisher described in. 6. A low foam fire extinguisher, which is characterized in that a chemical, water and compressed nitrogen gas are mixed and sealed in a device for generating foam for extinguishing fire.