JPH1073197A - Piping refrigeration construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an ice plug even in a large diameter piping for a short time with certainty by arranging a pipe passage sectional area reduction jig inside a piping correspondingly to a forming position of coolant, and performing refrigeration by each jig. SOLUTION: Coolant 14 such as liquid nitrogen is held on a surface of a piping 10 through a jacket 12 across a portion to be mended. In order to form an ice plug 16 inside the piping 10 by cooling function of the coolant 14, an elastic bag 18 is arranged inside the piping 10. A cylinder for supplying air and liquid nitrogen is connected to the elastic bag 18 which is expanded by opening a plug of the cylinder. Volume of the ice plug 16 can remarkably be reduced. During a forming process of the ice plug 16, the elastic bag 18 is automatically arranged on the center of the piping 10. A portion hard to refrigerate at the center of the piping 10 is closed by the elastic bag 18, and water stopping is enabled by the ice plug 16 housing the elastic bag 18 inside the piping 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe freezing method, and in particular, when performing work such as repair or replacement of a pipe, surely removes a portion of the pipe center which is hard to freeze when water is stopped using an ice plug. The present invention relates to a pipe freezing method for stopping water.

[0002]

2. Description of the Related Art Conventionally, for example, as shown in FIG.
At the repair / replacement point 3a where a crack or the like is generated in the middle of the path from the water tank 1 to the pipe 2, the valve 4 interposed between the paths leading to the point 3a is closed, and the water tank 1 is closed. After the flow of liquid from is shut off, repair and replacement work is performed.

[0003] However, at the repair / replacement location 3b where no valve is disposed around the periphery, the water of the tank 1 and the pipe 2 is drained, and then the repair / replacement work of the pipe is performed. For this reason, if the water filling after the operation is also taken into consideration, the time and cost are increased. Therefore, when repairing or replacing parts like 3b,
A freezing method has been considered in which a part of a flow pipe to the repair / replacement point 3b is formed with a water plug 5 by an ice plug (Japanese Patent Application Laid-Open Nos. 51-102220 and 63-26).
No. 491).

As shown in FIG. 8, a jacket 7 for holding a cooling medium 6 such as liquid nitrogen is formed around the pipe 2 on the outer surface of the pipe 2 to locally freeze the liquid 8 in the pipe. An ice plug (ice plug) 9 is formed to temporarily stop the flow of the liquid inside the pipe.

[0005]

However, in order to stop the liquid inside the pipe using the above-mentioned conventional ice plug, it is necessary to completely freeze the liquid at the center of the pipe. As the diameter increases, the time to completely freeze increases. In large-diameter piping,
There is a technical problem that an ice plug cannot be applied to a large-diameter pipe because the temperature is balanced in a state where an ice layer having a constant thickness is formed on the inner surface of the pipe and the pipe does not completely freeze to the center of the pipe.

Therefore, the present invention provides a pipe freezing method in which an ice plug can be formed inside a pipe in a short time and reliably in a pipe freezing method using an ice plug, and which can be applied to a large-diameter pipe. The purpose is to:

[0007]

In order to achieve the above-mentioned object, a pipe freezing method according to the present invention uses a cooling medium to freeze a fluid inside the pipe from the pipe surface and to stop the water from being stopped by an ice plug. In the freezing method, a pipe section reduction jig is arranged inside a pipe corresponding to a position where a cooling medium is provided, and the jig is frozen for each jig to form an ice plug.

In this case, the jig for reducing the cross section of the pipeline may be formed of an inflatable bag or a metal body, and the metal body or the bag may be frozen to form an ice plug. Alternatively, the jig for reducing the pipe cross section may be hollow, and the cooling medium may be supplied and filled therein.

More specifically, a split T-shaped pipe is attached to a pipe repair location, and a hole is drilled in a pipe wall of the pipe by a punching means connected to the split T-shaped pipe. Stop the water, insert a pipe cross-section reduction jig such as an elastic bag through a pipe wall hole, insert and arrange it before and after the repair location while opening the water stop by the split T-tube, and arrange the cross-section reduction jig. The outer periphery of the pipe is frozen with a cooling medium to freeze the fluid inside the pipe together with the jig for reducing the cross section of the pipe to form an ice plug before and after the repair point.

[0010]

According to the above construction, the jig for reducing the cross-section of the pipeline is inserted from the opening of the tank or the like, guided to the ice plug formation location adjacent to the repair and replacement section, and the frozen volume of the frozen section of the pipe is repaired with the pipe. By reducing only the space between the fixtures, the number can be reduced, and the repair and replacement work of the piping can be performed in a short time and reliably. By forming the pipe cross-section reduction jig by using a bag, the pipe cross-section can be reduced in freezing volume regardless of the pipe size. The freezing of the outer peripheral surface side of the metal body in the portion is promoted. Furthermore, by providing a cooling medium inside the jig with a hollow structure, the effect of accelerating freezing is significantly increased, and the effect of shortening the time required for ice plug formation required for repairing and replacing pipes is great. Become.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete embodiment of a pipe freezing method according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an explanatory sectional view showing a piping freezing method according to the first embodiment, in which freezing is promoted by using an elastic bag as a pipe section reducing jig. A cooling medium 14, such as liquid nitrogen, is held on the surface of the pipe 10 via a jacket 12 with the pipe repaired portion interposed therebetween, and an ice plug 16 is formed inside the pipe. The ice plug 16 is formed by the cooling action of the cooling medium 14. When the ice plug 16 is formed in the pipe, the volume of the ice plug 16 is reduced by installing the elastic bag 18 in the pipe 10 and expanding the bag. Extremely reduced.

FIGS. 2 to 4 show a procedure for carrying out a freezing method using a jig for reducing the cross-section of a pipeline comprising the elastic bag 18.

First, as shown in FIG.
Attach the split T-tube 20 to the repair location. This split T-tube 2
0 is a half cylinder body 22a, 22 that can surround the pipe 10.
b, one of which is provided with a branch pipe 24. The branch pipe 24 is equipped with a valve 28 that is linked to a handle 26.
A flange portion 29 is formed at the tip of the branch end 24. This may be a commercially available product.

Next, as shown in FIG. 2B, a drill holder 30 is mounted via the flange portion 29. The drill holder 30 has a flange portion 32 and can be flange-connected to the split T-tube 20.
4 is formed with a drill insertion hole 34 along the center. An electric drill device 37 equipped with a drill 36 is attached to the drill holder 30, the drill 36 is inserted from the insertion hole 34, and a hole is formed in the pipe wall of the pipe 10 to form a pipe wall hole 38. .

After drilling the pipe 10, the drill 36 is moved to a position where the valve 28 of the split T-tube 20 can be opened and closed while the drill 36 is inserted into the drill holder 30, and the valve 28 is closed to stop water. Then, as shown in FIG. 2 (3), the drill 36 is removed. At the same time, a pair of elastic bags 18 as a pipe section reduction member is prepared. A supply cylinder 40 for supplying air, liquid nitrogen or the like is connected to the elastic bag 18 so that the elastic bag 18 can be inflated by opening the cylinder 40.

Next, as shown in FIG.
A pair of elastic bags 1 inserted from the drill insertion hole 34
8 are passed through the tube wall holes 38 and installed at the ice plug execution positions 42, respectively. This may be performed using an operation wire or the like. Then, the cylinder 40 is opened, and the elastic bag 18 is inflated.

After the elastic bag 18 is inflated, as shown in FIG. 3 (2), the jacket 12 is placed on the outer peripheral surface of the pipe 10 at the ice plug execution position 42, and the cooling medium 14 such as liquid nitrogen is applied to the jacket 12. The inside is filled to form an ice plug 16. The formed ice plug 16 is used for the elastic bag 1.
8, the cross section of the pipeline is reduced, so that the elastic bag 1
8 is a small volume between the outer surface of the pipe 8 and the inner surface of the pipe 10, and the time from freezing to the formation of the ice plug 16 is greatly reduced.

After the formation of such an ice plug 16, FIG.
As shown in (3), the split T-tube 20, the drill holder 30,
Jacket 12 with cooling medium 14, elastic bag 18
The cylinder 40 connected to is removed. Thereafter, the repair / replacement unit 44 can be cut without draining the entire piping route. After cutting the repair / exchange section 44, the flange 46 is welded to the cut pipe end.

Next, as shown in FIG.
The connection of the gate valve 50 and the drill holder 30 to the newly connected T path pipe 48 is connected to 4. After the ice plug 16 is melted, the drill holder 30, the elastic bag 18
To remove.

According to this embodiment, the volume of the ice plug 16 formed by the action of the cooling medium 14 of the jacket 12 is greatly increased because the elastic bag 18 is located inside the freezing point and the amount of freezing volume is reduced. Is reduced. And
The ice plug 16 connects the elastic bag 18 to the piping 1 during the production process.
Since it is naturally disposed at the center of the pipe 0, the hard-to-freeze portion at the center of the pipe is closed by the elastic bag 18, and the inside of the pipe 10 is stopped by the ice plug 16 containing the elastic bag 18. As a result, even when the freezing method is performed by attaching the refrigerant jacket 12 to the outer periphery of the pipe, a water stopping effect can be easily given to the center of the pipe, and the freezing method can be performed even for a large-diameter pipe. Become.

FIG. 5A shows a second embodiment using an insertion type freezing promoting jig. This is a water tank 5
This is a preferred example in the case where the repair / exchange unit 44 is located at a position close to 1. When the ice plug 16 is to be implemented at the position indicated by the broken line in the figure, a steel ball 56 as an insertion-type freezing promoting jig to which a wire 54 is connected is inserted from the opening 52 of the water tank 51, and the implementation position of the ice plug 16 is set. Guide to 42. In this manner, similarly to the case where the elastic bag 18 is used, as shown in FIGS. 5 (2) to 5 (3), the ice plug 16 is placed inside the pipe without being frozen to the center of the pipe. Can be formed.

FIG. 6 shows a third embodiment.
This shows a modification of the insertion-type freezing jig. This insertion-type freezing promotion jig is installed inside the piping to reduce the freezing volume inside the piping, but also efficiently promotes freezing from inside the piping. For this purpose, a jig is formed by a hollow container 60 having a cavity 58 inside, and this is connected to an external cold / heat source 64 (a cylinder of liquid nitrogen or the like) from the opening of the water tank 51 using a tube 62 instead of a wire. And the jig body also supplies a cold heat source to the freezing section. This embodiment has the effect of shortening the freezing time as compared with the previous example.

[0024]

As described above, according to the pipe freezing method according to the present invention, in a pipe freezing method in which a fluid inside the pipe is frozen from the pipe surface using a cooling medium and the pipe is stopped with an ice plug, Since the pipe section reduction jig is arranged inside the pipe corresponding to the arrangement position of the cooling medium and is frozen for each jig to form an ice plug, there is an effect of reducing the frozen volume. In addition to being able to perform water stoppage due to freezing in a short time, repairing and replacing pipes can be performed in a short time and reliably, and especially, ice plugs are used for large-diameter pipes that could not be completely frozen in the past. Repair and replacement work that has been made possible.

[Brief description of the drawings]

FIG. 1 is a vertical and horizontal sectional view showing an arrangement configuration of an elastic bag used in a freezing method according to a first embodiment.

FIG. 2 is a work process (first example) of the freezing method according to the first embodiment;
FIG. 3 is an explanatory diagram showing the third step.

FIG. 3 is a work step (fourth step) of the freezing method according to the first embodiment;
FIG. 7 is an explanatory diagram showing the sixth to sixth steps.

FIG. 4 is a work process (No. 7) of the freezing method according to the first embodiment;
-8th process).

FIG. 5 is a work explanatory view using steel balls used for a freezing method according to a second embodiment and a vertical and horizontal cross-sectional view showing an arrangement configuration.

FIG. 6 is an explanatory diagram of a work using a hollow container used for a freezing method according to a third embodiment and a sectional configuration diagram of the hollow container.

FIG. 7 is an explanatory diagram of pipe repair.

FIG. 8 is an explanatory sectional view and a perspective view of a conventional freezing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Piping 12 Jacket 14 Cooling medium 16 Ice plug 18 Elastic bag 20 Split T pipe 22a, 22b Half pipe 24 Branch pipe 26 Handle 28 Valve 29 Flange part 30 Drill retainer 32 Flange part 34 Drill insertion hole 36 Drill 37 Electric Drilling device 38 Pipe wall hole 40 Cylinder 42 Ice plug execution position 44 Repair / replacement part 46 Flange 48 T pipe 50 Gate valve 51 Water tank 52 Tank opening 54 Wire 56 Steel ball 58 Cavity 60 Hollow container 62 Tube 64 Cold heat source

Claims (5)

[Claims] In a pipe freezing method in which a fluid inside a pipe is frozen from a pipe surface using a cooling medium and the pipe is stopped by an ice plug, a pipe cross-section reduction and reduction is performed inside the pipe corresponding to an arrangement position of the cooling medium. A pipe freezing method, wherein tools are arranged and frozen for each jig to form an ice plug. 2. The pipe freezing method according to claim 1, wherein the jig for reducing the cross section of the pipeline is formed of an inflatable bag, and the entire bag is frozen to form an ice plug. 3. The piping freezing method according to claim 1, wherein the jig for reducing the cross section of the pipeline is formed of a metal body. 4. The jig for reducing the cross-section of a pipe is formed hollow.
2. The method according to claim 1, wherein a cooling medium can be supplied and filled into the hollow portion. 5. A split T-shaped pipe is attached to a pipe repair location, and a hole is drilled in a pipe wall of the pipe by a drilling means connected to the split T-shaped pipe. A pipe cross-section reduction jig such as an elastic bag is inserted and arranged through the pipe wall hole before and after the repair location while opening the water blocking by the split T-shaped pipe, and the outer periphery of the arrangement position of the cross-section reduction jig is cooled. A pipe freezing method characterized by freezing the internal fluid of the pipe together with the jig for reducing the cross section of the pipe with a medium to form an ice plug before and after the repaired part.