JP3830705B2 - Disaster prevention method at gas pipe construction site - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disaster prevention method at a gas pipe construction site, and more specifically, an unexpected gas leak at a gas pipe construction site where a bypass pipeline is installed by blocking both sides of a construction section of an embedded city gas pipeline. The present invention relates to a disaster prevention method for dealing with fire caused.
[0002]
[Prior art]
First, construction such as partial replacement of the buried city gas pipeline will be described with reference to FIG. Reference numeral 1 denotes an existing pipeline of city gas buried in the ground. The construction process is as follows. (1). Excavation shafts A and B are formed on both sides of the construction section D. (2). With the pipe line connected, the pipe pipe is drilled and the bypass pipe 4 is attached. (3). A bag insertion hole is drilled between the attachment location of the bypass pipe 4 and the construction section, and after inserting the bag 7 (gas blocking member) from this insertion hole, the bag 7 is inflated to block the gas flow on both sides of the construction section. To do. (4). While the pipe of the bypass pipe 4 is opened and gas is supplied across the construction section, construction such as replacement is performed.
[0003]
In the field around the excavation shafts A and B for performing the gas pipe construction described above, an unexpected situation such as shrinkage or breakage of the bag occurs, and gas leakage occurs from the bag insertion hole drilled in the gas pipe. There is a risk. As one means for avoiding this danger, a diffusion pipe 8 is erected on the bag insertion hole, and the leaked gas is discharged out of the excavation shafts A and B through the diffusion pipe 8. Things have been done.
[0004]
[Problems to be solved by the invention]
In the gas pipe construction described above, if a gas leak occurs from the bag insertion hole drilled in the gas pipe, there is a risk that fire may ignite due to the leaked gas. This primary fire can be dealt with by extinguishing the fire by installing a fire extinguisher at the construction site of the gas pipe and putting a digester into the fire. However, this primary fire may completely damage the bag. In this case, a large amount of gas will be ejected around the excavation shaft after the fire has been extinguished. There is a risk of causing secondary disasters.
[0005]
The present invention has been proposed in order to cope with the above-described circumstances, and for a gas fire at a gas pipe construction site, it has become possible to prevent a secondary disaster caused by a gas jet simultaneously with extinguishing the fire. The purpose is to provide a disaster prevention method.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the disaster prevention method in the gas pipe construction site according to the present invention is to form excavation shafts on both sides of the construction section in the buried gas pipeline, and to provide a gas blocking member in the gas pipeline in the excavation shaft. a disaster prevention method in the gas pipe construction site to be inserted, to damage of the gas shut-off member of a fire occurring in the insertion point near the gas barrier member, the periphery the insertion point, the extinguishing water and the superabsorbent polymer The mixture is surrounded by a high-viscosity gel-like body imparted with high viscosity, and gas ejection from the insertion site is blocked simultaneously with extinguishing the fire . More specifically, the high-viscosity gel-like body includes a thermal gel-forming body.
[0007]
According to the disaster prevention method at the gas pipe construction site having the above characteristics, the high-viscosity gel introduced when the gas barrier member is damaged by a fire around the gas barrier member insertion point in the excavation shaft at the gas pipe construction site. By surrounding the area around the gas blocking member insertion point where the gas blocking member has been damaged by the fire, the gas that blows out from the gas blocking member insertion point at the same time as the fire is blocked to prevent secondary disasters such as gas explosions. To prevent.
[0008]
In addition , the high-viscosity gel-like body is a mixture of fire-extinguishing water and a highly water-absorbent resin, giving a high viscosity so that the fire can be extinguished by being put into the fire location and at the same time the gas blocking member insertion location It is possible to shut off the gas injected from.
[0009]
Further, by incorporating the thermal gel formers in highly viscous gel-like material of the high viscosity of moderate to highly viscous gel-like substance containing extinguishing water is thermally gelled is applied by heating at the time of introduction into the fire place Adhesion and gas barrier performance are improved.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing a disaster prevention method at a gas pipe construction site according to one embodiment of the present invention. The figure shows a construction site around the excavation shaft A formed on one side of the construction section. Reference numeral 1 is a gas pipe, 2a and 2b are saddles for attaching a bypass pipe, 3 is a connecting joint, 4 is a bypass pipe, and the gas pipe 1 is provided with a bag insertion hole 1a which is a gas blocking member. The bags 7 and 7 are inserted through the insertion hole 1a. In this gas pipe construction site, there is a risk that a fire may ignite due to the fire igniting the gas leaked from the insertion hole 1a through the bag 7. FIG. 1 shows a facility for extinguishing the gas fire. One end of a supply hose 14 is connected to a hose 13 for sucking out the fire water from the fire extinguishing water tank 11 by a fire water pump 10. The other end of 14 is connected to a container 12 containing a highly water-absorbent resin and a thermal gel forming body, and the discharge port 16 of the discharge hose 15 is directed to the fire location.
[0011]
According to the construction method shown in FIG. 1, the superabsorbent resin and the thermal gel forming body are supplied from the container 12 into the hose 13 through the supply hose 14 by the suction force of the fire-extinguishing water pump 10, and the fire is extinguished in the hose 13. Water, a highly water-absorbent resin, and a thermal gel forming body are mixed, and the mixture is discharged from the discharge port 16 to the fire spot via the discharge hose 15. The mixture mixed in the hose 13 becomes a gel-like body containing fire extinguishing water having a certain degree of fluidity, and the gel-like body containing fire extinguishing water is thrown into the fire site so that the contained thermal gel forming body is caused by the flame. It is heated and gelled to give high viscosity. As a result, the periphery of the insertion hole 1a of the bag 7 is surrounded by a highly viscous fire-extinguishing water-containing gel-like body, and the secondary fire is prevented by shutting off gas ejection from the insertion hole 1a along with extinguishing the primary fire. It becomes possible to prevent.
[0012]
2 and 3 are explanatory views showing other embodiments (the same parts as those in the example of FIG. 1 are denoted by the same reference numerals, and a part of the description is omitted). In the construction method of FIG. 2, fire extinguishing water is sent from the fire extinguishing water tank 11 through the hose 13 to the discharge hose 15 by the fire extinguishing water pump 10, and the supply hose 14 is connected to the discharge hose 15 so The heat-resistant resin and the thermal gel forming body are mixed with fire-extinguishing water in the middle of the discharge hose 15, and the fire-extinguishing water-containing gel-like body is discharged from the discharge port 16. In the construction method shown in FIG. 3, the water-absorbing resin and the thermal gel forming body are put directly into the fire place through the supply hose 14 and the discharge port 14a or not through them. And fire extinguishing water is thrown in from the discharge port 16 on the water-absorbent resin and thermal gel forming body thrown in on the fire part, these are mixed and a fire extinguishing water containing gel-like body is formed, and the insertion hole 1a periphery is made high Surround with a gel containing viscous fire extinguishing water.
[0013]
As the superabsorbent resin used in the present invention, water absorption is fast, swelling property is high, water retention is good, and there is no toxicity, but acrylic acid polymer sodium salt, Suitable are starch-acrylic acid graft copolymers, saponified vinyl ester-unsaturated carboxylic acid copolymers, crosslinked polyethylene oxide, and the like.
[0014]
In addition, as the thermal gel former used in the present invention, alkyl cellulose powder or hydroxyalkyl cellulose powder in which an aqueous solution is thermally gelled, specifically, water-soluble methylcellulose, hydroxypropylmethylcellulose, hydroxyethyl And methyl cellulose.
[0015]
In addition, although the thermal gel formation body was used in said Example, the mixture for providing high viscosity to a fire extinguishing water containing gel-like body is not limited to this, It is also possible to use a commercially available condensate. It is. By imparting high viscosity to the fire-extinguishing water-containing gel-like body, adhesion to the periphery of the insertion hole 1a is improved, and the blocking performance of the jetted gas is improved.
[0016]
【The invention's effect】
Since the present invention is configured as described above, fire gas and high water absorption are provided around the insertion point against damage to the gas blocking member due to a gas fire generated around the insertion point of the gas blocking member at the gas pipe construction site. Since the mixture with the resin is surrounded by a high-viscosity gel-like body with high viscosity, and the fire is extinguished, the gas ejection from the insertion point is shut off. The next disaster can be prevented.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a disaster prevention method at a gas pipe construction site according to an embodiment of the present invention.
FIG. 2 is an explanatory view showing another embodiment of the present invention.
FIG. 3 is an explanatory view showing another embodiment of the present invention.
FIG. 4 is an explanatory view showing construction such as partial replacement of an embedded city gas pipeline.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas pipeline 4 Bypass pipe 7 Bag 10 Fire extinguishing water pump 11 Fire extinguishing water tank 12 Container 13 Hose 14 Supply hose 15 Release hose 16 Release port

Claims (2)

It is a disaster prevention construction method in a gas pipe construction site where excavation shafts are formed on both sides of a construction section in a buried gas pipeline, and a gas blocking member is inserted into the gas pipeline in the excavation shaft,
A high-viscosity gel-like body that imparts high viscosity to a mixture of fire-extinguishing water and a highly water-absorbent resin around the insertion location against damage to the gas cutoff member due to a fire that occurred around the insertion location of the gas cutoff member A disaster prevention method at a gas pipe construction site, characterized in that it is surrounded by a gas pipe and shuts off gas emission from the insertion point simultaneously with extinguishing the fire . The high viscous gel-like body, disaster prevention method in the gas pipe construction site according to claim 1, wherein to include thermogelling former.

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