JPH11115052A - Lining method of pipe conduit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly conduct both insertion and expansion-restoration of a folding pipe into a pipe conduit by forcibly cooling a pipe given a folding work immediately before the inlet of a pipe conduit at its outer surface from the outside while being restrained in the state to be set stationarily in a folded shape. SOLUTION: A pipe 1 passes through a deformation working zone A to a restraint cooling zone B during movement from a drum 2 toward a pipe conduit inlet a1. While being passed through the deformation working zone A, the pipe 1 is gradually deformation worked from a flat pipe shape to a U-shaped folded shape, and its effective outer diameter is reduced to be a size capable of being inserted in a pipe conduit (a). During the period of passing through the restraint cooling zone B, a U-shaped folded pipe is subjected to a forcible cooling operation in a configurationally restrained shape. A forcible cooling device 9 is installed over the substantially entire length of the restraint cooling zone B, and a cooling spouting mold 9a and cold air blowing mold 9b are applied so that the pipe is set stationarily by forcible cooling in a configurationally restrained shape as being folded into a U-shaped form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method of lining a pipeline,
More specifically, the present invention relates to a pipe lining method using a plastic hard or semi-hard pipe as a lining material.

[0002]

2. Description of the Related Art Conventionally, as the above-mentioned lining method, a plastic hard or semi-hard pipe is wound in a roll shape in a state where it is deformed into a U-shaped folded shape so that the effective outer diameter is reduced in advance. Insert the pipe into the pipeline while pulling it out of the roll under the heat-softened state.After inserting in the pipeline, expand and restore the pipe to its original shape by heating and pressurizing from inside, and into the pipeline. A lining method to be applied has been proposed (for example,
-42220).

[0003]

According to the above lining method, since the pipe is folded in advance so as to reduce the effective outer diameter, the pipe can be inserted into the pipe relatively smoothly. However, if the pipe is wound up in a roll in a state where it has been folded in advance, the folded portion will have a habit during the storage period before use at the construction site, and this will remain as permanent distortion. Therefore, when expanding and restoring the pipe in the pipeline, there is a problem in restoring the expansion of the portion having the kinks, and the pipe cannot be restored to a circular shape in some cases. In addition, especially the folded part a inside the lower end of the U-shape (see Fig. 6)
Is reverse to the expansion recovery direction Y, so expansion recovery requires considerable difficulty. As a result, countless fine cracks (so-called 'whitening phenomenon') are caused and quality deterioration is caused, and sometimes cracks are broken and construction is impossible. There were problems such as falling into.

[0004]

In order to solve the above problems, the inventors of the present invention have conducted intensive studies and, in the course of the research, have folded the pipe into a folded portion, particularly a folded portion A which is inverted in the direction of expansion and restoration Y. We tried to perform the above-mentioned folding process immediately before insertion into the pipeline, based on the idea that the expansion and restoration of the pipe could be performed smoothly if the habit was not attached. The result was obtained. However, when the pipe folded in the U shape is released from the folding process, the U-shaped portion tends to return to the shape before the processing as shown by the imaginary line in FIG. 6 and the effective outer diameter decreases. As a result, a new problem has been encountered in that the pull-in resistance at the time of insertion into the pipeline increases, and insertion into the pipeline becomes difficult. In particular, in the case of polyethylene pipes, the elasticity is not completely lost even in the heat-softened state, so that there is a great tendency to return to the original shape when released from the restraint during the deformation processing.

The inventors of the present invention have conducted intensive studies to overcome the above-mentioned new problems, and as a result, have found that a pipe that has been folded immediately before the entrance of a pipeline is kept in a folded state while being restrained in the folded state. It has been found that when the surface is forcibly cooled from the outside and fixedly set in the above-mentioned folded shape, both insertion of the above-mentioned folded pipe into the pipe and expansion and restoration can be performed smoothly, and the present invention has been completed. It is.

That is, according to the present invention, a plastic hard or semi-rigid pipe having an outer diameter substantially equal to the inner diameter of a pipe line to be lined is carried into a construction site while being wound around a drum under a flat tubular shape. Then, the pipe is heated and softened by the internally supplied heating fluid, and is moved toward the entrance of the pipe while being pulled out of the drum under the softened state,
During the movement toward the pipeline entrance, the flat tube is folded into a U-shape to reduce the effective outer diameter, and after the folding process, the pipe outer surface is forcibly cooled in a state where the outer surface of the pipe is constrained in a U-shape, and the U-shape is formed. It is fixed in a folded shape, then inserted into the pipeline, and after insertion into the pipeline, the folded pipe is expanded and restored to its original shape by heating and pressurizing from inside, and is attached to the inner surface of the pipeline. It relates to the characteristic pipe line lining method.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method of the present invention will be described below with reference to the accompanying drawings. In the method of the present invention, a pipe 1 (see FIG. 1) used as a lining material is formed into a tubular shape from hard or semi-hard plastic such as polyethylene, and has an outer diameter substantially equal to the inner diameter of a pipe a to be lined. For example, 90 to 10 of the inner diameter of the pipe a
It has an outer diameter equivalent to 0%. The wall thickness is 1
It is appropriately selected from the range of about 10 to 10%, for example, about 1 to 30 mm according to the outer diameter. The pipe 1 is wound in advance on a drum 2 in a flat tubular shape so as to make it easier to carry it into a construction site. The flat tubular winding of the pipe 1 around the drum 2 is usually performed while the pipe 1 is heated to near the softening point. However, in the case of semi-rigid, it may be performed at room temperature depending on the wall thickness. As the polyethylene pipe, for example, the density is 0.93 to 0.94 g / cm ³ , the tensile strength is 120 to 250 kg / cm ² , and the softening point is 110 to 12.
One at 0 ° C can be used.

At the time of construction, as shown in FIG. 1, the pipe 1 is carried into a construction site while being wound on a drum 2, and in this installation state, the pipe 1 is first heated and softened. For this purpose, a heating fluid such as steam is supplied into the pipe 1. The supply of steam into the pipe 1 is performed through a steam supply mechanism 3, and the supply mechanism 3 supplies the steam to the inside of the pipe 1 from the innermost layer of the winding layer. The steam supplied into the pipe 1 flows through the inside from the end side (innermost layer side) to the start end side (outermost layer side), and during this circulation, the pipe 1 is heated from the inside. By continuing the internal heating by such steam, the pipe 1 can be uniformly heated and softened over its entire length while being wound up on the drum 2. Such heating softening means itself is already well known.

The heating and softening operation of the pipe 1 prevents heat from dissipating into the atmosphere, and further maintains an atmosphere filled with heated air in order to keep the inner and outer layers of the pipe section uniformly heated and softened. This is performed in the heat-insulated casing 4. The casing 4 is provided with a heated air supply pipe 5 for filling with heated air. After the pipe 1 has been sufficiently softened to a state where it can be pulled out of the drum 2 by the internal heating by steam, the supply of steam into the pipe 1 is stopped, while the heat retention in the casing 3 is continued. The pipe 1 is moved from the drum 2 to the entrance a of the pipe a.
Pull out and move toward 1. The drawing out of the pipe 1 is performed by a pulling operation of a rope 6 connected to the tip as shown in FIG. The base end side of the rope 6 is wound around a winch (not shown) installed on the arrival shaft side via the start shaft b and the pipeline a, and the towing operation by the rope 6 is performed by operating the winch. .

As shown in FIG. 2, the pipe 1 passes from the deformation processing zone A to the constrained cooling zone B during the movement from the drum 2 to the pipeline entrance a1. Receive processing. While passing through the deformation processing zone A, the pipe 1 is gradually deformed from a flat tubular shape to a U-shaped folded shape as shown in FIG. 3, and its effective outer diameter is reduced to a size that can be inserted into the conduit a. Decrease. In the deformation processing zone A, a plurality of, for example, four processing roll devices 71 are provided.
To 74 are arranged in parallel in the moving direction of the pipe.
As shown in the figure, the deformation processing progresses gradually in the course of sequentially passing between the processing rolls 71a, 71b, 72a, 72b,... Of these roll devices 71 to 75, and finally the U-shaped folded pipe 1 'Is obtained. Until the deformation processing of the pipe 1 is completed, the softened state of the pipe,
In particular, in order to keep the softened state of the outer layer portion favorable, the pipe 1 passes through the heat retaining duct 10 until reaching the deformation processing zone A, and the deformation processing is received in the heat retaining hood 11.

The inside of the heat insulating hood 11 communicates with the inside of the heat insulating casing 4 through the inside of the heat insulating duct 10, and the heated air is supplied from the inside of the casing 4 into the heat insulating duct 10 and the heat insulating hood 11, respectively, until the deformation of the pipe 1 is completed. During
The pipe 1 can be shut off from the outside air. Processing roll devices 71 to 74 provided in the deformation processing zone A
When the processing rolls constituting the above are positively rotated in the pipe feed direction, the processing roll devices 71 to 74 function as pull-out rolls of the pipe 1 and pull out the pipe 1 from the drum 2 as the deformation processing progresses. it can.

In the constrained cooling zone B, a shape constraining device 8 and a forced cooling device 9 are installed. During the passage in the zone B, the U-shaped folded pipe 1 'is forcibly constrained in a shape constrained state. Receive cooling. The shape constraining device 8 is provided with a plurality of pinching rolls 8a... Arranged in parallel so as to constrain the shape of the pipe 1 'in a movable state. I can do it. In the middle of the row of the holding rolls 8a, for example, guide rolls 8b are provided at the start end, the middle and the end.

The forced cooling device 9 is installed over almost the entire length of the constrained cooling zone B, and a cooling water injection type 9a, a cold air blowing type 9b, etc. are applied alone or in combination.
2 shows the case where both are used together. The tendency of the pipe 1 'to return to its original shape is eliminated by forced cooling under the shape constrained state, and the pipe 1' is fixed and set in the U-shaped folded shape, and the U-shaped folded shape is stably maintained even after the shape constraint is released I do. By the way, in the case of polyethylene, even when heated and softened, the elasticity is not completely lost, and when released from the restraint of deformation processing, there is a strong tendency to return to the shape before processing,
By forcibly cooling the outer surface in the shape-constrained state, the tendency to return can be almost completely eliminated.

If the forced cooling becomes too excessive,
For example, in the case of a polyethylene pipe, the outer surface temperature of the pipe at the entrance of the pipe is 40, since the pipe 1 'may extremely decrease the flexibility and lose the passage property of the bent portion of the pipe.
Forced cooling of about ± 10 ° C. is appropriate. In addition, since the outer surface temperature of the pipe may be unnecessarily lowered due to cooling by the outside air in a severe cold season or the like, even if the pipe 1 'is internally heated by the circulation of steam so as to maintain the above temperature range. Good. After the confined cooling, the folded pipe 1 'is drawn into the pipe a, so that the pipe 1' can be smoothly inserted into the pipe a.

After the insertion of the pipe 1 'into the conduit a is completed, as shown in FIG. 4, the final pinching roll 8a1 is forcibly closed and the end of the pipe 1' is sealed, and then the starting end is closed. By supplying a heating fluid, for example, steam into the pipe 1 ′ from the side through the heating fluid supply pipe 12, and heating and pressurizing from inside to expand and restore the pipe 1 ′, the pipe can be lined in the pipe line a. The expansion restoration by the heating and pressurizing from the inside is performed without much time after the folding process, and therefore, while the folding habit is not substantially formed. FIG.
) Can be smoothly expanded and restored. In addition, since the expansion and restoration can be performed smoothly without difficulty, it is possible to avoid the deterioration of the quality of the lining due to the whitening phenomenon and the inability to perform the construction due to the occurrence of cracks.

[0016]

According to the method of the present invention, since the pipe is deformed into a U-shaped folded shape and fixedly set by forced cooling immediately after the deformation, it is possible to smoothly and smoothly insert the pipe into the pipeline. Since deformation processing is performed immediately before insertion into the pipeline, expansion and restoration can be performed smoothly and smoothly, and high-quality lining can be easily formed.It is particularly useful when applied to polyethylene pipe lining. is there.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an outline of a heating and softening step of a pipe in a construction method of the present invention and a construction apparatus applied to the construction method of the present invention.

FIG. 2 is an explanatory view schematically showing a state of a deformation processing step and a constrained cooling step in the method of the present invention.

FIG. 3 is an explanatory diagram showing a processing state from a flat tubular pipe to a U-shaped folded shape.

FIG. 4 is an explanatory view schematically showing a state of inserting a pipe into a pipe.

FIG. 5 is an explanatory view schematically showing a state of expansion and restoration of a pipe.

FIG. 6 is an explanatory view showing a U-shaped folding state of a pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe 1 'Folded pipe 2 Drum 3 Steam supply mechanism 4 Heat insulation casing 5 Heated air supply pipe 6 Traction rope 7 Processing roll device 8 Shape restraint device 9 Forced cooling device 10 Heat insulation duct 11 Heat insulation hood 12 Heated fluid supply pipe

Claims (4)

[Claims] 1. A plastic hard or semi-rigid pipe having substantially the same outer diameter as the inner diameter of a pipe line to be lined is loaded into a construction site in a state of being wound around a drum under a flat tubular shape, and then installed. The pipe is heated and softened by the heating fluid supplied from the inside, and is moved toward the entrance of the pipe while being pulled out from the drum under the softened state. To reduce the effective outer diameter, and after folding, U
In a state constrained in the shape of a letter, the outer surface of the pipe is forcibly cooled and fixedly set in a U-shaped folded shape, then inserted into the pipe, and after insertion in the pipe, the folded pipe is heated and pressurized from inside A pipe line lining method characterized by expanding and restoring the pipe to its original shape and attaching it to the pipe inner surface. 2. The lining method according to claim 1, wherein a hard or semi-rigid polyethylene pipe is used as the lining material. 3. The method according to claim 1, wherein after the heating and softening of the pipe is completed, the supply of the heating fluid into the pipe is stopped until the insertion of the pipe into the pipe is completed. Lining method. 4. A processing roll device for performing a deformation process from a flat tube to a U-shaped folded shape of a pipe by applying a plurality of processing roll devices in parallel with a feed direction of the pipe and gradually performing the deformation process. Is provided with at least a pair of processing rolls that respectively clamp and process the pipe, and at least one of these processing rolls is made to function as a pipe drawing roll by positively rotating in the feed direction of the pipe. 3. The lining method according to any one of 3.