JP3061669B2 - How to protect the inner circumference of existing pipes - 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 protecting foreign matter from adhering to an inner peripheral surface of an existing pipe used for flowing a liquid therein, and more particularly to an existing method for preventing seawater from entering the inside. The present invention relates to a method for protecting an existing pipe inner peripheral surface that can reliably prevent marine organisms from adhering to the pipe inner peripheral surface.

[0002]

2. Description of the Related Art There is a possibility that marine organisms carried by seawater may adhere to the inner peripheral surface of a pipe into which seawater can enter, such as a cooling pipe of a nuclear power plant. When marine organisms adhere to the inner peripheral surface of the cooling pipe, the attached marine organisms impede the flow of fluid inside, increasing the flow resistance of the liquid inside the pipe and decreasing the cooling efficiency. There's a problem. For this purpose, drugs, paints, and the like, which are disliked by marine organisms, are applied to the inner peripheral surface of the cooling pipe. Further, in order to prevent marine organisms from adhering to the inner peripheral surface of the pipe itself, a method of applying a spherical substance to the inner peripheral surface to increase the shearing force of seawater entering the inside is also known. Furthermore, Japanese Patent Publication No. 3-59754 discloses that when seawater flowing through a pipe is stagnant, by removing dissolved oxygen in the seawater, marine organisms are killed, and A method for preventing marine organisms from adhering to the inner peripheral surface is disclosed.

Further, Japanese Utility Model Laid-Open Publication No. 3-93672 discloses a belt-shaped member which becomes an inner peripheral surface of a spiral tube when a pipe inner peripheral surface is lined with a spiral tube manufactured by spirally winding a belt-shaped member. On one side, a film is previously adhered with an adhesive, thereby covering the inner peripheral surface of the spiral tube lining the inner peripheral surface of the pipe with the film. It is also known to remove marine organisms together with the film by peeling from the inner peripheral surface.

[0004]

As described above, in the method of applying a drug or the like to the inner peripheral surface of a pipe, there is a possibility that a substance which melts into the fluid from the drug may adversely affect the surrounding environment. Since the function of preventing the adhesion of marine organisms by the applied drug deteriorates with time, the adhesion of marine organisms cannot be prevented for a long period of time. Further, it is not easy to remove dissolved oxygen in seawater by the method disclosed in Japanese Patent Publication No. 3-59754.

In the method of applying a spherical substance to the inner peripheral surface of a pipe to prevent marine organisms from adhering, the effect greatly changes depending on the flow velocity of seawater entering the inside. The attachment of living organisms cannot be reliably prevented.

Further, in the method in which the inner peripheral surface of the spiral tube is coated with a film and the film is peeled off after the marine organisms have adhered, the film is attached to the inner peripheral surface of the spiral tube with an adhesive. In addition, the adhesive may deteriorate due to long-term use, and the film may peel off from the inner peripheral surface of the spiral tube. When the film peels off from the inner peripheral surface of the spiral tube, marine organisms directly adhere to the inner peripheral surface of the spiral tube, making it difficult to remove marine organisms.

The present invention has been made in order to solve such a problem, and an object of the present invention is to stably prevent an existing pipe from sticking to the inner peripheral surface of the existing pipe for a long period of time. It is an object of the present invention to provide a method for protecting the inner peripheral surface of an existing pipe which can be used for the following.

[0008]

According to the method for protecting the inner peripheral surface of an existing pipe according to the present invention, a strip is spirally wound, and the side edges of adjacent strips are overlapped with each other so that both are engaged. A lining step of manufacturing a helical pipe and lining the inner peripheral surface of an existing pipe with the helical pipe, and a sealing step of sealing a gap between both ends of the helical pipe and the end of the existing pipe. In this state, the step of functioning the existing pipe, and thereafter, the step of releasing the sealing of each end of the spiral pipe and the existing pipe, and disassembling the spiral pipe into a strip from the existing pipe to remove the strip Sequentially removing from the existing pipe, thereby achieving the above object.

[0009]

According to the method for protecting the inner peripheral surface of an existing pipe of the present invention, the inner peripheral surface of the existing pipe is lined with a spiral pipe so that the gap between the existing pipe and the spiral pipe at each end is sealed. Function. Therefore, the foreign matter does not adhere to the inner peripheral surface of the existing pipe, but adheres only to the inner peripheral surface of the spiral pipe. The spiral tube to which the foreign matter has adhered is disassembled into a strip and removed from the existing tube.

[0010]

Embodiments of the present invention will be described below. The method for protecting the inner peripheral surface of an existing pipe according to the present invention is implemented, for example, to protect the inner peripheral surface of a cooling pipe of a nuclear power plant.
In the method of the present invention, first, a cooling pipe 40 is lined with a spiral pipe 20, as shown in FIG. The helical tube 20 is manufactured by spirally winding the band-shaped body 10 by a tube-making machine 30 arranged to face the end of the cooling pipe 40. Then, the helical tubes manufactured by the tube making machine 30 are sequentially inserted into the cooling pipe 40.

The strip 10 used for manufacturing the spiral tube 20 is as follows.
As shown in FIG. 2, it has a strip-shaped substrate 12, and on the substrate 12, at an appropriate distance from one side surface 12 a,
A fitting ridge 13 is provided upright. The fitting ridge 13 is
Are continuous in the longitudinal direction. The fitting ridge 13 has a column portion 13a slightly longer than the thickness of the substrate 12, and an insertion portion 13b having a semicircular cross section disposed at the tip of the column portion 13a.

On the other side surface 12b side of the substrate 12, when the substrate 12 is spirally wound, as shown in FIG.
In order to allow the portion of the substrate 12 between the side surface 12a on the 13 side and the base end of the fitting ridge 13 to be fitted, the fitting ridge is formed by the thickness of the substrate 12.
A step-down portion 17 is formed on the protruding side of the step 13.
A hot melt adhesive for bonding to the step-down portion 17 is applied to the upper surface of the substrate 12 near the column portion 13a which can be fitted into the step-down portion 17.

The stepped portion 17 has an insertion portion for the fitting projection 13.
A fitting recess 18 formed in a semi-circular cross section having a semi-circular cross-section space into which 13b can be fitted projects in the same direction as the fitting ridge 13 along the longitudinal direction of the substrate 12. Is provided. A reinforcing rib having a T-shaped cross section is provided on the upper portion of the fitting recess 18.
14 is provided to extend upward. The reinforcing ribs 14 are formed integrally with the substrate 12 along the longitudinal direction of the substrate 12. The reinforcing ribs 14 are provided on the upper surface of the substrate 12 so as to extend upward in a protruding manner. And a flange portion 14b.

A plurality of reinforcing ribs 16 having a T-shaped cross section are provided between the fitting protrusions 13 and the fitting recesses 18 of the substrate 12 at appropriate intervals in the longitudinal direction of the substrate 12. Along the substrate
It is erected integrally with 12. Each reinforcing rib 16 is connected to the substrate 12
A support 16a formed orthogonal to the support, and the support 1
6a has a flange 16b provided at the tip of the column 6a in a state orthogonal to the column 16a. Each reinforcing rib 16 and 14
Each of the flange portions 16b and 14b
Are formed so as to be located in the same plane parallel to.

Such a band 10 is made of polyvinyl chloride,
It is manufactured by integral molding from a material such as polyethylene, polypropylene, polycarbonate, polyester, or a resin obtained by reinforcing these resins with glass fibers.

As shown in FIG. 1 (a), the belt-like body 10 is formed so that the surface side of the substrate 12 on which the fitting ridges 13, the reinforcing ribs 16, and the fitting concave ridges 18 stand are the outer peripheral side. The spiral tube 20 is wound spirally by the tube machine 30. As shown in FIG. 4, the tube forming machine 30 forcibly causes the belt-shaped body 10 introduced therein to be formed by a tube forming roller 31 having a predetermined helical angle and disposed on a cylindrical peripheral surface. After being curved, the belt-shaped body 10 is spirally wound sequentially. At this time, as shown in FIG. 3, the stepped portion 17 of the strip 10 fed to the tube making machine 30 is placed on the stepped portion 17 on one side of the substrate 12 already wound spirally. The other side portion of the substrate 12 adjacent to the fitting is fitted and overlapped, and the fitting protrusion 13 is fitted into the fitting recess 18 of the step-down portion 17. Then, the insertion portion 13b of the fitting ridge 13 is inserted into the space inside the fitting concave ridge 18, and the side portion of the superposed substrate 12 and the step-down portion 17 are bonded by hot melt adhesive. By doing so, both are engaged.

The helical tube 20 formed by the tube forming machine 30 in this manner is sequentially discharged from the tube forming machine 30 and inserted into the cooling pipe 40 as shown in FIG. You. At this time, the outer diameter of the spiral tube 20 is smaller than the inner diameter of the cooling pipe 40 so that a slight gap 41 is formed between the outer peripheral surface of the spiral tube 20 and the inner peripheral surface of the cooling pipe 40. Has been tubed.
Then, as shown in FIG. 1B, when the helical tube 20 is inserted into the cooling pipe 40 over the entire length of the cooling pipe 40, the formed helical tube 20 and the strip 10 are cut. . Thereafter, as shown in FIG.
In order to seal the gap 41 at each end of the spiral tube 20, a filler 42 such as mortar is filled, and the gap 41 is hermetically sealed.

In such a state, the cooling water pipe 40
In order to function, cooling water flows through the spiral tube 20. Then, as shown in FIG.
By flowing through the inside of the helical tube 20 for a long time,
A foreign substance 43 such as a marine organism adheres to the inner peripheral surface of the vehicle. Spiral tube 20
When foreign matter 43 such as marine organisms adheres to the inner surface of
As shown in FIG. 7, the fillers 42 at the respective ends of the cooling pipe 40 and the spiral pipe 20 are broken by a machine tool such as a drill. Then, the end of the band 10 forming the spiral tube 20 is pulled by, for example, human power from the portion which was on the tip side at the time of manufacturing the spiral tube 20, and the spiral tube 20 is pulled into the band 10
To dismantle. The band 10 is sequentially pulled out from the end of the cooling pipe 40, and foreign matter 43 such as marine organisms attached to the inner peripheral surface of the spiral tube 20 is removed together with the band 10. When the spiral tube 20 is dismantled to form the strip 10, the traction force is such that the thickness of the substrate 12 is 2 mm, the diameter of the insertion portion 13b is 3 mm, and the diameter of the cross section of the space in the fitting recess 18 is 3.2 to 3.0 mm. 30 ~ 40kg ・ f
Since the degree of force is sufficient, the spiral tube 10 can be easily disassembled into the strip 10 by human power. If a greater tractive force is required for dismantling the spiral tube 20, a machine such as a winch may be used.

When the spiral tube 20 is disassembled in this way and the belt-shaped body 10 is completely pulled out from the cooling pipe 40, foreign matter 43 such as marine organisms remains in the cooling pipe 40. In the cooling pipe 40, the inside of the cooling pipe 40 is cleaned by a known pipe cleaning machine that cleans the inner peripheral surface of the pipeline by jetting the jet water. And the cooling pipe after cleaning
As shown in FIG. 1 (f), the same operation as described above is repeated by the pipe-making machine 30, and the spiral pipe is again formed by the belt-shaped body 10 as shown in FIG.
20 is manufactured, and the inner peripheral surface of the cooling pipe 40 is lined.

As described above, according to the method of the present invention, since the inner peripheral surface of the cooling pipe 40 is lined by the spiral tube 20, when cooling water flows, the cooling pipe 40 is attached to the cooling pipe 40. There is no possibility that the foreign matter 43 of this type directly adheres. Also, if foreign matter 43 such as marine organisms adheres to the inner peripheral surface of the spiral tube,
The spiral tube 20 is disassembled into the belt-shaped body 10, and the belt-shaped body 10 is pulled out from the cooling pipe 40, so that marine organisms and the like attached to the inner peripheral surface of the spiral pipe 20 without damaging the existing cooling pipe 40. Foreign matter 43 is removed.

[0021]

According to the method for protecting the inner peripheral surface of an existing pipe according to the present invention, foreign substances are prevented from directly adhering to the inner peripheral surface of the existing pipe. I can do it.

[Brief description of the drawings]

1 (a) to 1 (f) are cross-sectional views showing steps of an example of a method for protecting an inner peripheral surface of an existing pipe according to the present invention.

FIG. 2 is a perspective view showing a band used for carrying out the method of the present invention.

FIG. 3 is a sectional view of a main part of a spiral tube formed by the strip.

FIG. 4 is a schematic diagram showing a pipe-making state by a pipe-making machine in an execution step of the method of the present invention.

[Explanation of symbols]

 10 Strip 13 Fitting ridge 16 Reinforcement rib 18 Fitting ridge 20 Spiral tube 30 Pipe making machine 40 Cooling pipe 41 Gap 43 Foreign matter

Claims (1)

(57) [Claims] A helical tube is manufactured by winding a belt-like body in a spiral shape, overlapping side edges of adjacent belt-like bodies and bringing them into an engaged state, and using the spiral tube to form an existing tube. A lining step of lining the inner peripheral surface, a sealing step of sealing a gap between the spiral pipe and an end of the existing pipe, and a step of allowing the existing pipe to function in such a state. Removing the sealing of each end of the spiral tube and the existing tube; and disassembling the spiral tube into a band from the inside of the existing tube and sequentially removing the band from the inside of the existing tube. Protection method.