JP2016003678A - Pipe regeneration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the efficiency of regeneration work by reducing labor of developing a metal plate inside a pipe.SOLUTION: Backing mats 4 are arranged in advance at required portions in the inner periphery of a pipe 1. Then, a plurality of metal plates 2, having a constant width and a length of the inner periphery or more of the pipe 1, are wound up by having the outer periphery thereof being bound so as to have an inner diameter smaller than that of the pipe 1, are inserted in the pipe 1, and when the binding is released, are developed and deformed by elastic restoring force of each metal plate 2 itself so as to extend along the inner periphery of the pipe 1. Both of peripheral end parts 21, 22 and both of width end parts 23, 24 of the metal plate 2 are positioned on the backing mats 4. Thereafter, both of the peripheral end parts 21, 22 adjacent to each other are coupled by welding, and the width end parts 23, 24 of the metal plate 2 adjacent to the other metal plate 2 which is similarly developed and deformed in the pipe 1, are coupled by welding to the width end parts 23, 24 of the other metal plate 2.

Description

  The present invention relates to a pipe regeneration method for regenerating a pipe by covering an aging pipe inner periphery with a metal plate.

  Patent Documents 1 and 2 disclose a method for regenerating this type of piping. The outline will be described with reference to FIGS. A plurality of metal plates 7 such as a stainless steel plate having a constant width wound to a smaller diameter than the above are put in an aged metal pipe 1 (FIG. 6). Then, these metal plates 7 are spread on the inner peripheral surface of the pipe 1 using a jack or the like, and the circumferential end portions 71 and 72 of each metal plate 7 are overlapped with each other (lap joint) to perform fillet welding 73. (FIG. 7). In this case, in order to prevent damage to the pipe 1, a refractory heat insulating material 74 such as glass fiber is disposed behind the lap joint portion as a backing.

  Further, as shown in FIG. 8, the gap generated in the width direction end portions 73 and 74 of the adjacent metal plates 7 has a rubber or resin seal ring 8 of a certain width from the inside of the pipe 1 so as to close the gap. Arranged to prevent leakage. A metal ring-shaped fixing plate 81 is brought into contact with the inner peripheral surface of the seal ring 8, and the seal ring 8 is pressed and held in the inner peripheral direction of the pipe by the spring force.

  In the joint portion 11 of the pipe 1, a wide rubber seal ring 6 extends from the inside of the pipe 1 between the width direction end portions 73 and 74 of the metal plate 7 disposed on the inner peripheral surface of the adjacent pipe 1. The ring-shaped fixing plate 61 is brought into contact with both end edges in the width direction of the seal ring 6 to hold the seal ring 6 in the inner circumferential direction of the pipe. Both end portions 611 and 612 of the fixed plate 61 are overlapped with each other as shown in FIG. 9, and are pressed from the inner peripheral side by a connecting plate 62 having a laminated structure. The connecting plate 62 is fixed by screwing a bolt 63 inserted into the elongated hole 621 into one end 612 of the fixing plate 61 and injecting a resin material into the elongated hole 621. Note that both end portions of the fixed plate 81 are also pressed from the inner peripheral side by a connecting plate with the same structure.

JP2002-122287A JP-A-2004-205020

  By the way, in the above-mentioned conventional pipe recycling method, it takes time and effort to expand the metal plate inserted in the pipe along the inner circumference of the pipe using a jack or the like. It was.

  Therefore, the present invention solves such a problem, and provides a pipe recycling method capable of reducing the time and effort required for deploying a metal plate in the pipe and improving the efficiency of the reproduction work. Objective.

  In order to achieve the above object, according to the first aspect of the present invention, a backing mat (4) is previously installed at a necessary location on the inner periphery of the pipe (1) and becomes smaller in the pipe (1) than its inner diameter. As described above, each of the metal plates (2) itself is wound by loading a plurality of metal plates (2) having a constant width and having a length equal to or longer than the inner periphery of the pipe and releasing the constraints. The metal plate (2) is expanded and deformed to a position along the inner periphery of the pipe (1) by elastic restoring force, and both circumferential ends (21, 22) of the metal plate (2) and the metal plate (2 ) Both ends in the width direction (23, 24) are positioned on the backing mat (4), and the circumferential ends (21, 22) adjacent to each other are welded and joined together in the pipe (1). Similarly, the width direction end portions (23, 24) of the metal plate (2) adjacent to the other metal plate (2) developed and deformed are arranged. The other metal plate (2) is welded to one another widthwise end portion (23, 24) of.

  In the first aspect of the present invention, when the restraint of each metal plate is released at a predetermined position adjacent to each other in the pipe, the outer diameter of the metal plate is expanded and deformed by the elastic restoring force of the metal plate itself to a position along the inner circumference of the pipe. Expanded. This eliminates the need to use a jack or the like to expand the metal plate as in the prior art, and the installation work of the metal plate is greatly reduced.

  In the second aspect of the invention, a carbon fiber mat (4) made of a pure carbon fiber nonwoven fabric is used as the backing mat.

  In the second aspect of the present invention, heat generated during welding is prevented from being transmitted to the pipe by the carbon fiber mat, so that both end portions in the width direction of adjacent metal plates and the adjacent end portions in the width direction of the metal plates are butted together. Can be joined by welding. Thereby, the protrusion part into piping is decreased significantly and the increase in distribution resistance of piping can be suppressed small.

  In addition, the code | symbol in the said parenthesis shows the correspondence with the specific means as described in embodiment mentioned later.

  As described above, according to the pipe regeneration method of the present invention, it is possible to reduce the time and labor required for deploying the metal plate in the pipe and to improve the efficiency of the regeneration work.

It is a fracture | rupture schematic side view of the piping reproduced | regenerated by the method of this invention which shows one Embodiment of this invention. FIG. 3 is a perspective view of a metal plate that is wound and bound and is released from binding. It is a partial expansion perspective view of the pipe inner periphery regenerated by the method of the present invention. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is sectional drawing along the VV line of FIG. It is a fracture | rupture schematic side view of the piping reproduced | regenerated by the conventional method. It is sectional drawing along the VII-VII line of FIG. It is a fragmentary sectional top view along the VIII-VIII line of FIG. It is the front view and sectional drawing of the edge part connection part of a fixing plate. FIG. 7 is a partial cross-sectional plan view taken along line XX in FIG. 6.

  The embodiment described below is merely an example, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

  FIG. 1 shows a broken side view of an example of a pipe regenerated by the method of the present invention. In FIG. 1, a metal plate 2 is disposed adjacently in a longitudinal direction in a pipe 1 such as an existing metal pipe or a reinforced plastic composite pipe (FRPM). As the metal plate 2 used in the present embodiment, a spring material rich in elastic restoring force is used. As an example, a 2.5 mm thick SUS304 1 / 2H stainless steel plate can be suitably used. Such a metal plate 2 has a length substantially equal to the inner circumference of the pipe, and the width is a numerical value obtained by dividing the length of the pipe by the number of installed metal plates 2 (four in this embodiment (FIG. 1)). And

  As shown in FIG. 2 (1), each of the metal plates 2 is wound so as to have an outer diameter (for example, 600 mmφ) that is about 1/3 of the inner diameter of the pipe 1, and is bound and restrained by a known binding member 3. It is charged in the pipe 1. When the binding of the binding members 3 of the metal plates 2 is released at a predetermined position adjacent to each other in the pipe 1 and the restraint is released, the metal plate 2 has its elastic restoring force as shown in FIG. The outer diameter is deformed by about 3 times. Therefore, the metal plate 2 is expanded to a position along the inner periphery of the pipe 1 by giving a slight assistance. Thereby, it is not necessary to push and spread the metal plate 2 using a jack or the like as in the prior art, and the installation work of the metal plate 2 is greatly reduced.

  By the way, prior to the installation work of each metal plate 2, both end portions 21 and 22 in the circumferential direction of the metal plate 2 developed along a predetermined region on the inner periphery of the pipe 1, that is, along the inner periphery of the pipe 1, are close to each other. As shown in FIG. 3, a carbon fiber mat 4 is adhered and disposed in a region where the two metal plates 2 and the left and right end portions 23, 24 in the width direction are adjacent to each other. Keep it.

  This carbon fiber mat 4 is manufactured by a method as described below, the manufacturing method of which is disclosed in Japanese Patent No. 4965730, and is a nonwoven fabric made of pure carbon fiber that does not contain a resin material or the like. Therefore, the heat resistant temperature can withstand a high temperature of about 3000 ° C. compared to a normal carbon fiber mat of 250 ° C. or lower.

  An example of manufacturing such a carbon fiber mat 4 is as follows. That is, the carbon fiber bundle is cut into a length of about 10 cm to make short fibers, which are loosened with a kneading machine to obtain a coarse cotton having a predetermined size in which the directions of the fibers are aligned. After opening the raw cotton in the opening cylinder, it floats in an air chamber formed between the opening cylinder and the suction cage that rotates in synchronization with the opening cylinder. A fiber mat is used. And this is shaped and cut with a needle punch to make a nonwoven fabric mat, and then cut to a required size to make a carbon fiber mat.

  In such a carbon fiber mat 4, as described above, the regions in which both ends 21 and 22 in the circumferential direction of the metal plate 2 are located close to each other, and the end portions 23 and 24 in the width direction of the adjacent metal plates 2 are mutually connected. It is arranged in a region located close to the backing for welding. An example of the thickness of the carbon fiber mat in this case is 5 mm, and the basis weight is 300 kg / m 2.

  By adopting such a structure, heat generated during welding (about 1700 ° C.) is prevented from being transmitted to the pipe 1 by the carbon fiber mat 4. As shown in FIG. Furthermore, the adjacent width direction both ends 23 and 24 of the adjacent metal plates 2 can also be directly coupled by butt welding 5 as shown in FIG. 5 without using a conventional seal ring.

  In addition, in the joint part 11 of the pipe 1, as in the prior art, a wide seal ring is provided between the widthwise ends of the metal plates 2 respectively disposed on the inner peripheral surface of the adjacent pipe 1 as shown in FIG. 6 and a fixing plate 61.

  As described above, according to the pipe recycling method of the present embodiment, a large number of seal rings provided in this portion by joining the adjacent widthwise ends 23 and 24 of the adjacent metal plates 2 with the butt weld 5. (Refer to FIG. 6) can be eliminated, and the circumferential ends 21 and 22 of each metal plate 2 can be joined by butt welding 5 instead of lap welding as in the prior art. Protruding parts are greatly reduced. As a result, an increase in the flow resistance of the pipe 1 can be reduced. In addition, leakage can be reliably prevented.

DESCRIPTION OF SYMBOLS 1 ... Piping, 2 ... Metal plate, 21, 22 ... Circumferential direction edge part, 23, 24 ... Width direction edge part, 3 ... Bundling member, 4 ... Carbon fiber mat (backing mat).

Claims (2)

A backing mat is set in advance at a necessary location on the inner circumference of the pipe, and the outer circumference is constrained to be smaller than the inner diameter of the pipe and wound around the pipe so that the length is equal to or longer than the inner circumference of the pipe. By inserting a plurality of metal plates having a width and releasing the restraint, the metal plates are developed and deformed to positions along the inner circumference of the pipe by the elastic restoring force of each metal plate itself, Both end portions in the width direction and both end portions in the width direction of the metal plate are positioned on the backing mat, and both the circumferential direction end portions adjacent to each other are welded and joined together, and other metal plates that are similarly expanded and deformed in the pipe A method of regenerating a pipe, comprising joining the width direction end portions of the adjacent metal plates to each other in the width direction end portions of the other metal plates. The pipe regeneration method according to claim 1, wherein a carbon fiber mat made of a pure carbon fiber non-woven fabric is used as the backing mat.

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