JPH11333934A - Regeneration of existing piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an existing pipeline capable of being lined with a regeneration pipe excellent in self-supporting strength without lowering an effective flow rate. SOLUTION: In a method for regenerating an existing pieline by lining the inner surface of the existing pipeline with a plurality of pipe liners made of a thermoplastic resin, as a plurality of the pipe liners 1, 1', ones each obtained by deforming a cylindrical body in a state imparting shape recovery thereto at shape memory temp. so as to reduce an outer shape cross-sectional area are used. A pluality of linining layers 100, 104' are formed on the inner surface of the existing pipeline through a process successively inserting these pipe liners 1 into the existing pipeline 3, a process internally heating the pipe liners 1, 1' to shape memory temp. to almost restore the shape of the original cylindrical bodies and a process internally pressurizing and expanding the cylindrical bodies 10, 10' in a remaining heat state by air to closely bond them to the inner surface of the existing pipeline to cool them by air to fix them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for rehabilitating an existing pipeline.

[0002]

2. Description of the Related Art Conventionally, as a method of rehabilitating an aging existing pipeline made of reinforced concrete pipe (fume pipe) or steel pipe, a new resin pipe having a predetermined length and a small diameter is sequentially connected to the existing pipeline. There is known a method in which a rehabilitation pipe is laid by inserting the pipe, and a backfill material such as mortar or a foaming resin material is injected into a gap between the pipe and the existing pipe to seal the pipe.

In the rehabilitation method using the backfill material, there is a problem that the effective flow rate is reduced because the inner diameter of the rehabilitation pipe is considerably smaller than the inner diameter of the existing pipe. It is necessary to lay a rehabilitation pipe while connecting the resin pipes in sequence, or to inject a backfill material into the gap with the existing pipe and seal it, resulting in poor workability and slow rehabilitation work. is there.

In view of this point, for example, Japanese Patent Laid-Open No.
No. 31 discloses that a U-shaped pipe liner having a shape recovery property into a cylindrical shape at a shape memory temperature of a thermoplastic resin is drawn into a pipe inner surface such as a sewage pipe and restored to a circular shape by thermal expansion, thereby reducing the pipe inner surface. A lining method has been proposed.

[0005] The pipe liner used in this method has high rigidity, and when inserted into an existing pipeline laid horizontally from a vertically dug manhole, it is bent at a small curvature so as to be inserted into the existing pipeline. Due to the necessity of insertion, the friction resistance at the entrance of the existing pipeline is large, and it is difficult to insert it.If forcible insertion is attempted, the existing pipeline may be damaged or the surface of the pipe liner may be damaged. Was. In that respect, we would like to use a pipe liner that is as thin as possible.However, if the wall thickness is reduced, the strength of the pipe will be insufficient. There is.

[0006]

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and provides a method for rehabilitating an existing pipeline which can be easily lined with a rehabilitation pipe having excellent self-standing strength without lowering the effective flow rate. The purpose of this is to provide.

[0008]

The invention described in claim 1 of the present application (invention 1) is a method for rehabilitating an existing pipeline in which the inner surface of the existing pipeline is lined with a plurality of pipe liners made of thermoplastic resin. Then, as the plurality of pipe liners, in a state where the performance of recovering the shape of the cylindrical body at the shape memory temperature is imparted, respectively, using those deformed to reduce the cross-sectional outer area, A step of sequentially inserting the pipe liner into the existing pipeline, a step of heating the pipe liner from the inside to a shape memory temperature to recover the shape to a substantially original cylinder, and thereafter, the cylinder in a residual heat state This is a method of rehabilitating an existing pipeline in which a plurality of lining layers are formed on the inner surface of the existing pipeline through a process of pressurizing the air from inside and expanding the airtight tube to closely adhere to the inner surface of the existing pipeline, and then cooling and fixing the air.

The invention described in claim 2 of the present application (Invention 2)
Is a method for rehabilitating an existing pipeline according to the first aspect of the present invention, in which an adhesive is interposed between the plurality of pipe liners to join a plurality of lining layers.

The invention described in claim 3 of the present application (the present invention 3)
Is a method for rehabilitating an existing pipeline according to the first aspect of the present invention, wherein a heating wire is interposed between the plurality of pipe liners, and a plurality of lining layers are fused by heating the heating wire.

The invention described in claim 4 of the present application (Invention 4)
Is a method for rehabilitating an existing pipeline according to the first aspect of the present invention, wherein at least two of the plurality of pipe liners are made of different materials.

In the present invention, examples of the material of the pipe liner include thermoplastic resins such as polyethylene which can be used as a normal rehabilitation pipe material, and medium density polyethylene and high density polyethylene are preferable.

In the present invention, the pipe liner has a concave portion along the axial direction on the outer surface thereof in a state where the cylindrical body extruded from the extruder is given a shape recovering shape at the shape memory temperature. Then, it is deformed so as to reduce the cross-sectional outer area, and a material wound around a drum in this state is used.

[0014]

According to the method of rehabilitating an existing pipeline according to the first aspect of the present invention, the plurality of pipe liners each have a reduced cross-sectional area in a state in which the shape of the cylindrical body is restored at a shape memory temperature. Steps of sequentially inserting these pipe liners into the existing pipeline using the deformed pipe line, and heating the pipe liner to the shape memory temperature from inside to recover the shape to the substantially original cylindrical body. Process, then
Forming a plurality of lining layers on the inner surface of the existing pipeline through a process of air-pressing and expanding the cylindrical body from the inside in a residual heat state and closely adhering to the inner surface of the existing pipeline, and then cooling and fixing it with air. As a result, the thickness of each pipe liner is reduced so as to share the thickness of each pipe liner as long as it has a self-standing strength that requires the total thickness of the lining layer formed by a plurality of pipe liners. When inserting each thinned pipe liner into the existing pipeline, the friction resistance at the entrance of the existing pipeline is small and easy to insert, and the existing pipeline is damaged because it is not forcibly inserted. In order to avoid dripping or damaging the surface of the pipe liner, the inner surface of the existing pipeline can be lined with a rehabilitated pipe with excellent self-standing strength without lowering the effective flow rate. Kill.

Since the lining layer is integrated by bonding the plurality of lining layers with an adhesive interposed between the plurality of pipe liners, it is possible to perform lining with a rehabilitating pipe having more excellent self-standing strength. it can.

[0016] Since the heating wire is interposed between the plurality of pipe liners and the plurality of lining layers are fused by heating the heating wire, the lining layer is integrated. Can be lined with pipes.

Since at least two of the plurality of pipe liners are made of different materials, it is possible to form a lining layer having characteristics in each lining layer.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing one of a plurality of pipe liners used in the present invention, and FIG.
It is a front view explaining the manufacturing process of the pipe liner shown in FIG.

As shown in FIG. 1, the pipe liner 1
Made of a thermoplastic resin such as high-density polyethylene and has a concave portion 11 along the axial direction on the outer surface in a state where the shape of the cylindrical body is restored at the shape memory temperature, and the cross-sectional outer area is reduced. It is modified so that

As a method of manufacturing the pipe liner 1, for example, as shown in FIG. 2, a cylindrical body 10 is extruded by an extruder 21, and the cylindrical body 10 is cooled by passing through a cooling water tank 22. In the deforming device 23, the outer surface is crushed in the axial direction at the shape memory temperature, the concave portion 11 is provided on the outer surface, and the traverse portion 25 is pulled by the pulling device 24 so as to reduce the cross-sectional outer area. And a method of winding it on the drum 26 via an external device.

Hereinafter, the steps of an example of the method for rehabilitating an existing pipeline according to the present invention will be described with reference to FIG. In this example,
2 in the same manner as the first pipe liner 1 shown in FIG.
According to the method described with reference to the above, two second pipe liners 1 ′ which are slightly smaller than the first pipe liner 1 are used.

First, as shown in FIG.
A first pipe liner 1 is laid in a substantially horizontal direction from a manhole (not shown) in the existing pipeline 3 over the entire length thereof.

Next, as shown in FIG. 3 (b), steam is continuously supplied into the first pipe liner 1 and heated to the shape memory temperature from the inside thereof, so that the first cylindrical body 10 After the shape is recovered, as shown in FIG. 3 (c), compressed air is sent to the inside of the cylindrical body 10 to expand and pressurize the inside from the inside to make it closely adhere to the existing pipeline 3, and in this pressurized state, cooling is performed. After fixing, the first lining layer 100 is formed on the inner surface of the existing pipeline.

Further, as shown in FIG. 3D, a second pipe liner 1 ′, which is slightly smaller than the first pipe liner 1, is placed in the existing pipeline 3 on which the first lining layer 100 is formed. Lay it over its entire length.

Next, as shown in FIG. 3 (e), the steam is continuously supplied into the second pipe liner 1 'and heated to the shape memory temperature from the inside thereof, so that the substantially original cylindrical body is formed. After the shape is recovered to 10 ', as shown in FIG. 3 (f), compressed air is sent to the inside of the cylindrical body 10' to expand and pressurize the inside of the cylindrical body 10 'so as to be in close contact with the existing pipeline 3, and Then, the cooling and fixing is performed to form the second lining layer 100 'on the inner surface of the existing pipeline, and the rehabilitation of the existing pipeline 3 having the two lining layers 100 and 100' is completed.

At this time, the thickness of the rehabilitated pipe composed of the first lining layer 100 formed by the first pipe liner 1 and the second lining layer 100 'formed by the second pipe liner is required. The thickness of the first pipe liner 1 and the thickness of the second pipe liner 1 'can be reduced so as to share the thickness of the first pipe liner 1 and the second pipe liner 1'.

When the pipe liner thus thinned is inserted into the existing pipeline, the frictional resistance at the entrance of the existing pipeline is small, and the pipe liner is easily inserted.
Damage to existing pipelines and damage to the surface of the pipe liner can be avoided.

The material of the first pipe liner 1 and the second
Pipe liner made of a different material, for example, the first pipe liner 1 is made of a material having high self-supporting strength, and the second pipe liner 1 'is made of a material having excellent organic solvent resistance and gas permeation resistance. By using such a material, it is possible to form a rehabilitating tube having high self-standing strength and excellent in organic solvent resistance and gas permeation resistance.

Next, another example of the method for rehabilitating an existing pipeline according to the present invention will be described with reference to FIG. In this example, the first lining layer 1 is formed on the inner surface as shown in FIG.
As shown in FIG. 4, the second pipe liner 1 'is inserted into the existing pipe line 3 with the adhesive 4 applied around it, and the following FIG. 3 (d) to (f) are inserted. Through the steps described with reference to the drawings, a rehabilitating pipe in a state where the first lining layer and the second lining layer are joined to each other is formed. By doing so, since the layers are joined, it is possible to form a rehabilitated pipe having higher self-supporting strength.

Next, still another example of the method for rehabilitating an existing pipeline according to the present invention will be described with reference to FIG. In this example,
As shown in FIG. 3 (c), the second pipe liner 1 'is placed around the heating wire 5 in the existing pipeline 3 having the first lining layer 100 formed on the inner surface as shown in FIG. After the steps described below with reference to FIGS. 3D to 3F are passed, the heating wire 5 is energized to melt the first lining layer and the second lining layer. A rehabilitated tube in a worn state is formed. By doing so, the layers are fused to each other, so that a rehabilitated pipe having higher self-standing strength can be formed.

[0031]

The method for rehabilitating an existing pipeline according to the present invention is as described above, so that the effective flow rate is not reduced without damaging the existing pipeline or damaging the surface of the pipe liner. The inner surface of the existing pipeline can be lined with a rehabilitated pipe having excellent self-standing strength.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of an example of a pipe liner used in the present invention.

FIG. 2 is a front view showing an example of a method of forming the pipe liner shown in FIG.

FIGS. 3A to 3F are explanatory views of an example of a method for rehabilitating an existing pipeline according to the present invention, and FIGS.

FIG. 4 is a front view for explaining one step of another example of the existing pipe rehabilitation method of the present invention.

FIG. 5 is a front view illustrating one step of still another example of the method for rehabilitating an existing pipeline according to the present invention.

[Explanation of symbols]

 1, 1 'pipe liner 3 existing pipeline 4 adhesive 5 heating wire 10, 10' cylindrical body 100, 100 'lining layer

Claims (4)

[Claims] 1. A method for rehabilitating an existing pipeline in which an inner surface of the existing pipeline is lined with a plurality of thermoplastic resin pipe liners, wherein each of the plurality of pipe liners is formed into a cylindrical body at a shape memory temperature. In the state where the ability to recover the shape has been given, using those that have been deformed to reduce the cross-sectional outer area, those pipe liners, in order,
A step of inserting the pipe liner into the existing pipeline, a step of heating the pipe liner to a shape memory temperature from the inside to recover the shape to a substantially original cylinder, and then expanding the cylinder by applying air pressure from the inside in a residual heat state A method for rehabilitating an existing pipeline, wherein a plurality of lining layers are formed on the inner surface of the existing pipeline after a step of bringing the inner pipe into close contact with the inner surface of the existing pipeline, followed by a process of air cooling and fixing. 2. The method according to claim 1, wherein an adhesive is interposed between the plurality of pipe liners to join the plurality of lining layers. 3. The method according to claim 1, wherein a heating wire is interposed between the plurality of pipe liners, and a plurality of lining layers are fused by heating the heating wire. . 4. The method according to claim 1, wherein at least two of the plurality of pipe liners are made of different materials.