JP2648829B2 - Fire extinguishing method for cable in canal and foam fire extinguisher - Google Patents

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 tunnel, and a foam fire extinguishing device.

[0002]

2. Description of the Related Art When a fire occurs in an underground cable laid in a tunnel, a ground fault or the like may be caused to cause a catastrophic disaster. It is considered that a cable fire is most likely to occur at a connecting portion or a crossing portion of the cable. Therefore, at present, an appropriate fire extinguishing device is installed around this connection part to take the initial fire extinguishing system.However, in the conventional fire extinguishing method, a valve interlocked with an appropriate heat sensing device is opened, and a pump is used around the connection part by a pump. Is sprayed with water.

[0003]

However, in such a method, when the installation location is long, various restrictions are caused by a decrease in water pressure due to the rating of the pump and the like.
There is a possibility that the intended purpose cannot be achieved as it is. To deal with this, a large pump and corresponding equipment and space are required, and a large tank for storing fire-fighting water must be installed at fixed distances, which poses problems in securing cost and space. is there.

[0004]

In order to solve such a problem, the present invention employs the following configuration. In other words, according to the first aspect of the present invention, the periphery of the cable connection portion or the crossover portion is previously surrounded by a net-like fire-resistant cloth, and when a fire occurs at the connection portion or the crossover portion, the cable is surrounded by the fire-resistant cloth. It is intended to extinguish the cable fire by releasing bubbles into the closed space. As this fire resistant cloth,
Fire resistant fabrics composed of aramid fibers are suitable. Further, from the viewpoint of balance between ventilation and maintenance of bubbles, it is desirable that the coarse density of the refractory cloth is about 10 mesh. Further, these are those in which the periphery of the cable connection portion or the intersection is surrounded by a net-like fire-resistant cloth, which surrounds the cable connection portion and the like with an appropriate frame, and the net-like fire-resistant cloth is surrounded by the frame. In some cases, the outer periphery of the cable connection part is directly covered with a fire-resistant cloth.

According to a second aspect of the present invention, a net cloth made of a heat-resistant and high-strength fiber is directly covered over the outer periphery of the connecting portion or the crossing portion of the cable in the sinus by loosely covering the end thereof. It is fixed to the outer periphery of the connection or the crossover, and when a fire occurs at the connection or the crossover, a bubble is released between the inner periphery of the mesh cloth and the outer periphery of the connection or the crossover to cause a cable fire. Trying to extinguish the fire. This heat-resistant and high-strength fiber is made by combining aramid fiber and silica fiber, and has high strength and can withstand high temperature sufficiently.

According to a third aspect of the present invention, a plurality of net-like cloths made of heat-resistant and high-strength fibers are arranged and covered directly on the outer periphery of the cable connecting portion or the crossing portion in the cave along the connecting portion or the crossing portion. The end 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 at the connecting portion or the crossing portion, the inner periphery of each of the 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.

Claim 4 has been proposed as a high-foaming type fire extinguisher suitable for use in such a fire extinguishing method. This is a device in which a drug is sprayed on a mesh by a compressed gas to generate a fire-extinguishing foam, and a cross section of the mesh (a cross section in a direction perpendicular to a surface of the mesh) is substantially corrugated. The reticulated body refers to a perforated metal, a wire mesh, or the like having many small holes.

[0008] Further, the peripheral portions of a large number of holes in the mesh body are protruded toward the spraying source side.

Further, in the fire extinguisher which generates foam for fire extinguishing, a low foaming fire extinguisher in which a chemical, water and compressed nitrogen gas are mixed and sealed is proposed in claim 5.

[0010]

According to the first aspect, the fire in the space surrounded by the refractory 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 fire-resistant cloth, and the fire-resistant cloth is not broken, the foam is securely held, and the fire is extinguished.

According to the present invention, when a fire occurs at a cable connecting portion or a crossing portion covered with a net cloth made of a heat-resistant high-strength fiber, this is detected and the inner periphery of the net cloth and the connecting portion or the connecting portion are detected. Bubbles are released between the outer periphery of the crossing portion and the foam is filled while inflating the mesh cloth. This extinguishes the fire by enclosing the flame. In the case of an explosion or the like, the operation is the same as that of the first aspect. According to the third aspect, for each of the net cloths covering the outer periphery of the cable connection portion or the intersection portion where the fire has occurred, this is detected, and between the inner periphery of the net cloth and the connection portion or the outer periphery of the intersection portion. The foam is released, filling the foam while inflating the mesh cloth. This allows the flame to be enveloped faster. In the case of an explosion or the like, the operation is the same as that of the first aspect.

According to the fourth aspect of the present invention, since the cross section of the net is substantially corrugated, the surface area, that is, the number of small holes is increased as compared with the conventional flat net, and the peripheral portion of the hole is closer to the spray source. Because of this, the drug stays in the reticulated body for a longer time than the conventional type. Also, the amount of drug that covers the pores increases. Therefore, bubbles can be efficiently generated, and the generated bubbles are hardly broken and the foam maintenance time is long.

According to the present invention, when a fire is detected, the valve of the low-foaming fire extinguishing system opens, and foam is released immediately. At that time, unlike the above-described high-foaming fire extinguisher, there is no need to inhale air. Also, at this time, the compressed nitrogen gas is mixed with the drug and water and sealed, so that when these drugs are released, the compressed nitrogen gas is rapidly opened and expanded, so that the drugs and the like are released at these pressures. It is released vigorously and the generation of bubbles can be made very smooth.

[0014]

1 is an explanatory plan view of a first embodiment of the present invention.
FIG. 2 is an explanatory side view, and FIG. 3 is a cross-sectional view taken along line AA in FIG. 1, where 1 is a cable, 2 is a cable connector,
Is an inner side wall of the sinus, and 4 is a floor surface in the sinus. In general, the cable 1 to be laid in the cave is laid such that an appropriate receiving bracket 6 is horizontally fixed to a stand 5 supported on the inner wall of the cave, and the cable is placed on the receiving bracket 6.

Using these metal fittings 5, an appropriate frame 7 made of a channel material or an angle material is installed so as to surround the cable connecting body 2, and the frame 7 has a fire resistance of 10 mesh. Cloth 8 is attached. The frame 7 is formed by sequentially fixing rectangular components made of a channel material or an angle material to the stand metal 5. At the penetrating portions of the cable 1 at both ends in the longitudinal direction, substantially conical penetrating portion covering bodies 9 and 10 made of refractory fibers are fixed. A fire extinguisher attachment 11 is fixed to the stand 5 on the outer side of the inner wall 3 of the passageway of the frame 7, and a high-foaming fire extinguisher 12 is fixed to the fire extinguisher attachment 11. A duct 13 is provided at the outlet of the high-foaming fire extinguisher 12.
The outlet of the duct 13 is directed to an opening formed in a wire mesh panel 14 installed on the inner wall 3 side of the substantially central portion of the frame 7.

Next, the details of the high-foaming fire extinguisher 12 will be described with reference to FIGS. 4, 5 and 6. The main body is substantially cylindrical, the outer peripheral wall 15 has a double structure, and the hollow The portions are partitioned by an annular partition 16 to form annular compartments 17, 18, respectively. The compartment 17 contains a drug together with compressed nitrogen gas, and the compartment 18 contains water together with high-pressure nitrogen gas. 19 is a double compartment 17,
This is a pressure equalizing valve provided in a bypass which connects the water supply 18 to the water. By opening the pressure equalizing valve 19, the water and the medicine are maintained at the same pressure and mixed at an appropriate mixing ratio.

An automatic mixing valve 20 is provided at the center of the main body of the high-foaming fire extinguisher 12, and the medicine and water stored in the compartments 17 and 18 are mixed here, and are passed through a constant flow valve 21 to a nozzle. From 22, it is injected toward the foam net 23 stretched at one end opening of the main body by the pressure of nitrogen gas. The surrounding air is entrained when passing through the foam net 23, and a large amount of fire extinguishing foam is released as shown in FIG. The opening and closing of the automatic mixing valve 20 is automatically performed by a signal from a heat-sensitive detection head 24 provided at an appropriate position in the frame 7.

As shown in FIGS. 4 and 5, the foamed net 23 is formed of a punched metal having a wavy cross section, and the number of the holes 25 increases as the surface area increases. It was adopted. In addition, the peripheral portions of these holes 25 formed in a large number protrude toward the spraying source (the nozzle 22 side) as shown in FIG. By raising in this way, high-quality fire extinguishing foam can be efficiently generated.

The main equipment for the first embodiment is constructed as described above. When a fire occurs in the cable connector 2, the heat is detected by the detection head 24, and the operation signal is immediately output to the automatic mixing device. It is sent to the valve 20 to open it. Then, a large amount of foam gushes from the foam net 23 and is discharged from the duct 13 into a space surrounded by the fire-resistant cloth 8 to extinguish the fire. Also, unlike simply spraying a foam toward a fire, the foam can be released and filled in a certain section, so that the fire can be extinguished in a very short time. At this time, since the refractory cloth 8 has a net shape, air is easily evacuated when the bubbles occupy the space and are filled, and
By adopting a mesh-sized one, bubbles do not leak out.

In a normal state, the surroundings of the cable connection body 2 are made of a net-like fire-resistant cloth 8, so that the ventilation is good.
It does not impair the cooling required for underground cables.
The underground high-voltage cable swings back and forth and left and right. However, since the fire-resistant cloth 8 is rich in flexibility, as shown in the embodiment, it is easy to attach the through-hole coverings 9 and 10 and the cable 1 It is easy to secure adhesion around the penetrating part of
However, there is no hindrance even if such rocking occurs. In addition, the use of the fire-resistant cloth 8 prevents arc damage, and also reduces blasts and explosions caused by explosions when an arc is generated.
Damage to personnel and various devices can be suppressed.

The high-foaming fire extinguisher 12 employed in the first embodiment is of a so-called integral type, in which nitrogen gas, chemicals and water are set in one main body. In order to supply the nitrogen gas, the chemical, and the water, a separate high-foaming fire extinguisher 31 as in the second embodiment shown in FIG. 7 can be provided. In this type, a cylinder 32 containing a medicine and water is separately provided, which is installed on the floor surface 4 in the sinus, and fixed to the frame body is made of a member such as an automatic mixing valve, a nozzle, or a foaming net. . Therefore, when the space between the inner wall 3 of the tunnel and the upright 5 cannot be made large,
It is effective when preparing a large amount of nitrogen gas, chemicals and water.

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.
FIG. 3 is a sectional view taken along line B, in which a cable 1, a cable connector 2, a sinus inner wall 3, a sinus floor 4, an upright 5, and a receiving bracket 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 square net-like cloths 33 made of heat-resistant and high-strength fibers obtained by combining 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 are respectively covered by directly covering the outer circumference of the cable connecting body 2, and each end of each mesh-like cloth 33 is tied with a cord 34. In this way, the outer periphery of the cable connector 2 is covered with the two net-like cloths 33.

Further, two low-foaming fire extinguishing devices 35 for supplying foam to the two net-like cloths 33 are supported on an appropriate supporting material such as the metal fittings 5, and each of the low-foaming fire extinguishing devices 35 derived from these low-foaming fire extinguishing devices 35 is supported. The other end of the pipe 36 is branched into three to form branch pipes 36a, and the distal ends of the respective branch pipes 36a are arranged at intervals along the outer periphery of the cable connector 2, and the detection head is provided at the distal end of each branch pipe 36a. 37 are provided. Each of these detection heads 37 is put inside, and the outer periphery of the cable connector 2 is covered with each of the mesh cloths 33.

In the case of the third embodiment, when a fire occurs at the location of the cable connector 2, the heat is detected by the nearest detection head 37, and the valve of the low-foaming fire extinguishing system 35 is immediately activated. Open and a large amount of bubbles are generated in each detection head 37
Release from Then, foam fills the outer peripheral space of the cable connector 2 surrounded by the mesh cloth 33, inflates the mesh cloth 33, and is discharged between the inner circumference of the mesh cloth 33 and the outer circumference of the cable connector 2 to extinguish the fire. You.

In the third embodiment, the cable connector 2
Is covered with two net-like cloths 33 arranged side by side in the longitudinal direction of the cable connecting body 2. However, the present invention is not limited to this, and the net-like cloth 33 is enlarged and the cable connecting body 2 is covered with one net-like cloth 33. Is also good. In each of the above embodiments, the cable connector 2 has been described. However, the present invention is not limited to this, and a similar method can be employed in a cable crossing portion.

[0026]

According to the first aspect of the present invention, the fire is extinguished by discharging foam into a space enclosed in advance, so that the fire extinguishing at the connection portion of the cable in the sinus can be performed quickly and effectively.
In addition, installation of equipment and instruments for that purpose is also easy. By using a high foaming device, space can be saved, and a pump or the like is not required.

[0027] Further, since the foam wraps the flame in this manner, smoke generated in the event of a fire is temporarily contained, and the operator can be blamed for a safe place during this time. In addition, the explosive sound caused by the blast generated at the time of the fire can be prevented by the fire-resistant cloth and the foam in the space serving as a sound dampener, and the fire-resistant cloth can prevent flying objects. In addition, since the surroundings of the cable are surrounded by the fire-resistant cloth made of an insulator, it is possible to prevent the failure due to the arc, and furthermore, it is possible to disperse the blast when the arc is generated and to release the blast from the mesh of the fire-resistant cloth. Moreover, since it is rich in flexibility, unlike a metal net such as a wire net, the cable penetration portion has excellent adhesion 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, since the cable connecting body or the crossover portion is directly covered with a net cloth made of heat-resistant and high-strength fiber in advance, the equipment and the equipment are provided. However, it is simpler, has better workability, is less bulky, and is suitable for use in narrow sinuses. The heat-resistant and high-strength fibers have high strength and can withstand high heat, can hold bubbles inside, and surely help fire extinguishing.

According to the third aspect of the present invention, in addition to the effects of the first aspect, the net-like cloth made of heat-resistant and high-strength fiber covering the cable connector or the crossover portion is divided into a plurality of pieces. The space filled with foam is small, so that a fire occurrence location around the cable connection or the crossover can be wrapped with foam more quickly.

According to the fourth aspect, since the cross section of the net is substantially corrugated, the surface area, that is, the number of small holes is increased as compared with the conventional flat net, and as a result, a larger amount of bubbles is generated. And quick fire extinguishing can be realized. 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 sinus.

It is possible to generate bubbles more efficiently. In addition, the generated foam is of good quality which is hard to break and has a long time to maintain the foam. Therefore, it is possible to provide an optimal foam for extinguishing a fire.

According to claim 5, the low-foaming fire extinguisher is extremely simple in construction, requires no other power source, can be installed very easily anywhere, and therefore takes up little space. Further, when generating foam, the high-foaming fire extinguisher must suck clean air. However, in the event of a fire, smoke may also be sucked, and in such a case, sufficient foam may not be generated. However, in this low-foaming fire extinguisher, it is not necessary to suck in air because compressed nitrogen gas is used when foam is generated, so that foam can be sufficiently generated even when smoke is generated. Furthermore, since the compressed nitrogen gas is mixed with the drug and the water and sealed therein, when releasing these drugs, the drug is released vigorously by the expansion force of the compressed nitrogen gas, so that bubbles are generated more reliably and sufficiently. be able to.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view showing a state where a cable connection body is surrounded by a fire-resistant cloth in a first embodiment.

FIG. 2 is an explanatory side view showing a state where the cable connection body is surrounded by a fire-resistant cloth in the first embodiment.

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

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

FIG. 5 is a longitudinal sectional view of the foamed net according to the first embodiment.

FIG. 6 is a side sectional view of the high-foaming fire extinguisher according to the first embodiment in a foaming state.

FIG. 7 is an explanatory view from the axial direction in a second embodiment in which the high-foaming fire extinguishing device is a separate body.

FIG. 8 is an explanatory plan view showing a state where a cable connection body is surrounded by a fire-resistant cloth in a third embodiment.

FIG. 9 is an explanatory side view showing a state where a cable connection body is surrounded by a fire-resistant cloth in a third embodiment.

FIG. 10 is a sectional view taken along the line BB in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cable 2 Cable connection body 3 Cave side wall 4 Cave floor surface 6 Receiving bracket 7 Frame 8 Fireproof cloth 9 Penetration part covering body 10 Penetration part covering body 12 High foam fire extinguishing device 13 Duct 22 Nozzle 23 Foaming net 25 Hole 33 Mesh Cloth 35 Low foam fire extinguisher 36 Pipe 37 Detection head

Claims (5)

(57) [Claims] 1. A cable connection portion or a crossing portion in a cave is previously surrounded by a net-like fire-resistant cloth, and when a fire occurs at the connection portion, the space is surrounded by the fire-resistant cloth. A method for extinguishing a cable, comprising releasing foam. 2. A net-like cloth made of heat-resistant and high-strength fiber is directly covered with a net cloth loosely over the connection part or the crossing part of the cable in the tunnel, and the end of the net-like cloth is fixed to the connection part or the crossing part. A fire extinguishing method for a cable, characterized in that, when a fire occurs in the connecting portion or the crossing portion, bubbles are released between the inner periphery of the mesh cloth and the outer periphery of the connecting portion or the crossing portion. 3. A net-like cloth made of a heat-resistant and high-strength fiber is arranged along the connecting portion or the crossover portion, and is covered with a loose cloth directly on the outer periphery of the connecting portion or the crossing portion of the cable in the cave. The end of each mesh cloth 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 mesh cloth and the outer periphery of the connecting portion or the crossing portion are connected. A method for extinguishing a cable, characterized in that bubbles are discharged in between. 4. A device for generating a fire-extinguishing foam by spraying a drug or the like on a mesh by a compressed gas, wherein a cross section of the mesh is made substantially corrugated, and a peripheral portion of a large number of holes in the mesh is blown by a spray source. A high-foaming fire extinguisher characterized by being raised to the side. 5. A low-foaming fire extinguishing apparatus, wherein a fire-extinguishing foam is generated by mixing and enclosing a chemical, water and compressed nitrogen gas.