JPH02194927A - Engineering method for repairing inner face lining of existing pipe - Google Patents

Abstract

PURPOSE:To contrive to rapidly repair the inner face lining of an existing pipe by a method wherein molten resin material is fed from an extruder to a die and, at the same time, pressurizing air is fed through the die into the inner space of a resin lining and, in addition, the outer space of the resin lining is evacuated. CONSTITUTION:In an existing pipe 1 having vertical or horizontal bent portion, a die 2 is installed at the end of a pipe in a vacuum pump side pit 9. A collected hose 5 (a resin carrying hose 51, an air feed hose 52, a controlling cable and a towing wire 61), which is connected to the die, is laid in the existing pipe. From a melt resin extruder, which is installed outside the pipe, molten resin material is carried through the resin carrying hose 51 to a tip nozzle 21. After that, a trumpet-shaped molten resin, which is delivered from the die 2, is enclosed so as to form a balloon in order to apply internal pressure to it by charging pressurizing air from nozzles 22 in the die 2. After the state applied by the internal pressure is confirmed, a threaded cap is fixed to the end of the pipe at the vacuum pump side so as to connect a vacuum pump to the interior of the pipe in order to vacuumize the interior of the pipe. The molten resin is expanded to the inner face of the pipe by means of the internal pressure so as to be lined to the inner face of the pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for repairing the inner lining of existing pipes such as water and sewage pipes and gas pipes.

(B) Conventional technology Existing pipes such as water supply pipes, drainage pipes, sewage pipes, and gas pipes have become extremely uneven due to internal corrosion and foreign matter due to long-term use, and cannot be used as conduits. I can't stand it anymore.

Therefore, a repair method has traditionally been used in which the inside of the pipe is ground and cleaned and then lined with thermosetting resin.

As a lining method for existing pipes, JP-A-53-1286
It is disclosed in Publication No. 75. However, this method installs an extrusion device and a lining device inside the pipe and works while moving them, so it can be applied to straight large-diameter pipes, but it can be applied to pipes with curved pipes such as small- to medium-diameter pipe elbows. is difficult to apply.

Furthermore, the temperature inside the pipe increases due to the molten resin, but the heat is only released from the inside of the pipe to the surface and underground, and the remaining heat is accumulated inside the pipe, so in reality it is rarely cooled down. Met. Furthermore, when curing, the tube ends harden quickly, and there is a tendency for uneven hardening to occur throughout the tube. However, until now there has been almost no means of forced cooling as a solution to this problem.For example, when water cooling is used, water vapor is generated at the same time as the molten resin is cooled, causing air bubbles to enter the lining material. This was causing contamination.

As described above, in the conventional method, cooling is slow, so the curing speed is also slow, and the upper part of the tube becomes thinner and the lower part of the tube becomes thicker due to its own weight.

So-called blurring occurred, and the uniformity of the film thickness of the new tube on the inner surface of the tube was lost.

(c) Problems that the invention sought to solve The problems that the invention sought to solve are wide ranging from large diameter pipes to small diameter pipes, and the inner lining of existing pipes can be repaired quickly and reliably, regardless of the presence or absence of a single-bent pipe section. The purpose is to obtain a construction method.

(d) Means for Solving the Problems The method for repairing the inner surface of an existing pipe according to the present invention involves lining and repairing the inner surface of an existing pipe by extruding a molten resin material into the pipe from a die that runs inside the pipe in the axial direction. In the construction method, the die is guided inside the pipe by a guide cart, the molten resin material is supplied to the die from an extruder installed outside the existing pipe, and a collection hoss is passed through a take-up machine installed outside the existing pipe. Connecting the guide cart and moving the guide cart in the tube axis direction1. supplying pressurized air to the interior space of the resin lining through the die;
The above problem is solved by means consisting of reducing the pressure in the external space of the resin lining.

It is also possible to reduce the pressure in the outer space of the resin lining in the vicinity of the die by passing through the die.

It is also possible to close one end of the existing pipe and reduce the pressure in the space on the back side of the resin lining while moving the die to the open other end.

(E) Embodiment A method for repairing the inner lining of an existing pipe according to the present invention will be explained with reference to FIGS. 1 to 4.

First, as shown in FIGS. 1 and 2, the construction method of the present invention involves extruding molten resin material 3 into the pipe from a die 2 running inside the pipe 1 in the direction of the pipe axis to coat the inner surface of the pipe 1. This is a method of repairing the lining.

The dice 2 are guided inside the tube by a guide cart 4. The guide cart 4 guides a collection hose 5, which will be described later. Existing pipe 1
A molten resin material 3 is supplied to the die 2 from an extruder (not shown) installed outside the pipe, and a guide cart 4 is connected to a take-up machine 6 installed outside the existing pipe 1 through a collection hose 5. ,
Move the guide cart in the direction of the tube axis. Pressurized air is supplied to the internal space 32 of the resin lining 31 by using the die 2, and at the same time, the external space 33 of the resin lining 31 is depressurized.

As best shown in FIG. 2, the molten resin material 3 is supplied into the die 2 by a hose 51, and is discharged from the nozzle 21 into the tube in a trumpet shape. Pressurized air is supplied into the die 2 by a hose 52 and from the nozzle 22 into the internal space 3.
It is injected into 2. The external space 33 is depressurized by an extraluminal vacuum pump 7 communicating therewith.

Due to these pressurizing and depressurizing actions, the resin lining 31 is brought into close contact with the inner surface of the tube. The resin is preferably a thermosetting heat-resistant resin.

As shown in FIG. 3, one end of the existing pipe 1 is closed with lI8, the tip of the molten resin is closed and swelled, and the back surface of the resin lining 31 is moved while moving the die 2 to the open other end. It is also possible to reduce the pressure in the side space 34.

Further, as shown in FIG. 4, the external space 33 of the resin lining 31 near the die 2 can be depressurized by passing the die 2. In this case, the die 2 is further provided with a pressure reducing nozzle 23 to suck air near the external space 33.

Next, the steps of the construction method of the present invention will be explained.

As shown in Figure 1, in an existing pipe 1 that has vertical or horizontal bends, the die 2 is
= Placed at the end and then connected the collected hose 5 (resin withdrawal hose 51 (resin part, heating and insulation part), air feed hose 52, control cable, traction wire 61) into the existing pipe using the conventional method (through Vig, etc.) Lay it down.

A molten resin extruder located outside the tube allows the molten resin material to be transported in a stable molten state to the tip nozzle 21 of the die 2 using a resin transport hose 51 (for example, equipped with a heat-insulating device such as a thin tube heater).

Thereafter, the trumpet-shaped molten resin discharged by the die 2 is sealed to form a balloon, and pressurized air is blown into the balloon from the nozzle 22 in the die 2 to apply internal pressure.

After confirming that internal pressure is applied, a threaded Wl is fixed to the end of the tube on the vacuum pump side, and a vacuum pump is connected inside to create a vacuum inside the tube. The vacuum pressure is approximately 10 to 50 cm1 (l), although it depends on the thickness of the lining resin and the pipe diameter.

The molten resin is spread out on the inner surface of the tube due to the internal pressure, and the mold advances in the direction shown in the figure (0.2 to 0.51!/l'1in).
As a result, the molten resin is lined.

By vacuuming from the outside and internal air pressure from inside the resin,
The resin conforms to the inner surface of the tube, and the film thickness becomes even. When a vacuum is applied, the resin is cooled and contracts, creating a gap between the inner surface of the tube and the resin, through which air is drawn by the vacuum to strengthen and evenly cool the tube.

Table 1 below shows an example of a test carried out using the above-mentioned process, in which an average film thickness was ensured on both the straight pipe section and the bent section, resulting in good results.

No. figure (to) Effect According to the construction method of the present invention, the following effects can be obtained.

■ By placing the extruder outside the pipe, it can be applied to a wide range of pipes, from small diameter pipes to large diameter pipes (80A to 400^).

■ Since internal pressure and vacuum are applied at the same time, moldability is good, but because it cools rapidly, there is little shrinkage and new pipes with good adhesion can be molded.

■ Since molten resin is used, new pipes with uniform thickness can be easily formed even on curved pipe sections.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of the construction method of the present invention, Fig. 2 is an explanatory diagram of the lining process of an example M of the construction method of the present invention, and Figs. 3 and 4 are explanatory diagrams of the lining process of another embodiment. figure. 1: Existing pipe 2: Dice 3: Molten resin material 4: Guide cart 5: Collection hose 6: Pulling machine 7: Vacuum pump 8: l! 21.22.23: Nozzle

Claims (1)

[Scope of Claims] 1. In a construction method for lining and repairing the inner surface of an existing pipe by extruding a molten resin material into the pipe from a die running inside the pipe in the axial direction, the die is guided inside the pipe by a guide cart. , a molten resin material is supplied to the die from an extruder installed outside the existing pipe, and a collection hose is connected to a take-up machine installed outside the existing pipe to connect the guide car, and the guide car is moved in the direction of the pipe axis. A method for repairing the inner surface lining of an existing pipe, which comprises moving the pipe, supplying pressurized air to the inner space of the resin lining through the die, and reducing the pressure in the outer space of the resin lining. 2. The construction method according to claim 1, wherein the external space of the resin lining near the die is depressurized by passing the die. 3. The construction method according to claim 1, wherein one end of the existing pipe is closed and the die is moved to the open other end while reducing the pressure in the space on the back side of the resin lining.