JPS6369576A - Lining method for inside wall surface of pipe - Google Patents

Abstract

PURPOSE:To enable formation of a coated film having an optional thickness on the inside wall surface of a pipe by reducing the pressure in the pipe to suck the high-viscosity lining material into the pipe, inserting a pig made of an elastic material into the pipe and pressing and moving the lining material forward via the pig. CONSTITUTION:The pressure in the pipe 1 to be treated is reduced to suck the high-viscosity lining material 5 into the pipe so that the lining material 5 is accumulated at the inlet end of the pipe 1. The pig 6 made of the elastic material is inserted behind the lining material 5 to generate a pressure difference between the space behind the pig 6 and the space before the lining material 5, by which the lining material 5 and the pig 6 are integrally moved toward the outlet end side of the pipe 1. The need for cleaning the lining material supplying system at every end of the supply of the lining material is eliminated and the efficiency of the lining operation is extremely improved. The coated film of an arbitrary thickness between 0.5-4mm is formable on the inside wall surface of the pipe by changing the moving speed of the pig.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an improvement of a liquid phase lining method used for the rehabilitation of buried gas pipes, water pipes, etc. The present invention relates to a method for lining the inner wall surface of a pipe, which makes it possible to significantly improve lining work efficiency by filling the inner wall surface of a pipe.

(Prior art) Fig. 2 shows an example of the conventional liquid phase lining construction method. First, a sliding body F having elasticity is inserted into the pipe A to be treated, and the rear side of the sliding body F is inserted into the pipe A to be treated. A lining material G having high viscosity and fluidity is press-fitted into the tube by a pump H or the like, and the inside of the tube A to be treated is closed by the lining material G. Next, a pressurized fluid E is supplied into the tube A to be treated, and the lining material G is made to flow, thereby forming a lining film on the inner wall surface of the tube. (Samurai-dokoro Sho 60-14125
No. 7).

The sliding body F inserted into the pipe and the lining material G accumulated in the pipe are sequentially moved forward by the pressurized fluid E, and a lining film is formed on the inner wall surface of the pipe through which the lining material G has passed. The thickness of the lining film formed on the inner wall surface of the pipe is determined by the moving speed and viscosity of the lining material G, and the film thickness is controlled by adjusting the moving speed and the lining material viscosity.

However, in the conventional liquid phase lining construction method, a predetermined amount of lining material formed in advance is usually pumped
Since the lining material G is pumped into the WFA to be processed by the lining material G, it is necessary to clean the pump H and the like every time the injection of a desired amount of the lining material G is completed. This is because if the lining material is left in place until the next injection of lining material G, the function of the pump will be impaired due to hardening of the lining material.
As a result, there is a problem in that a lot of time and effort are required to inject the lining material, and work efficiency is significantly reduced.

Furthermore, in the conventional liquid phase lining method, the flow resistance of the lining material G depends on the condition of the pipe (the surface roughness of the inner wall surface of the pipe,
The speed of movement of the lining material G pulsates significantly even if the pressure of the pressurized fluid E is kept constant because the speed varies greatly depending on the pipe diameter, the curvature of the curved part, the pipe length, the pipe temperature, etc. As a result, in the case of pipes with many curves or long pipes, not only the thickness of the coating film formed on the inner wall surface of the pipe fluctuates greatly, but also many irregularities occur on the outer surface of the coating film. However, there is a problem in that a coating film having a uniform thickness and a smooth outer surface cannot be formed.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems in the conventional liquid phase lining construction method, namely: (1) The pump for pumping the lining material must be frequently cleaned; The aim of this project is to solve problems such as the time-consuming injection process, and the difficulty in forming a lining film with a uniform thickness and smooth outer surface. The pipe can be coated with high efficiency, with a relatively thick coating thickness of 0.5 to 4.0 cm, and with the desired uniform thickness over the entire length of the pipe including the elbow, and with a smooth outer surface. It is an object of the present invention to provide a method for lining the inner wall surface of a pipe by lining it with a coating film having the following properties.

(Means for solving the problem) The highly viscous lining material is suctioned by reducing the pressure inside the tube to be treated, and the lining material is placed at the inlet end of the tube to be treated.
At the same time, a pressure difference ΔP is generated between the rear space of a pig made of an elastic material provided behind the lining material and the curved blade space of the lining material, and the lining material and the pig are integrated into the pipe to be treated. A method for lining an inner wall surface of a pipe, characterized by moving the inner wall surface toward the outlet end side of the pipe.

(Function) By driving the exhaust device to reduce the pressure inside the pipe to be treated,
A predetermined amount of lining material is sucked into the pipe to be treated from the lining agent tank, and is deposited in a layer in front of the pig in a state that blocks the pipe line.

The layered lining material and the pig move forward at a substantially constant speed corresponding to the pressure difference ΔP between the front and rear spaces, and a lining film is formed on the inner wall surface of the pipe.

When the moving speed of the pig is increased by increasing the pressure difference ΔP, the pig made of an elastic material is subjected to a resistance force by the lining material, and for example, if the pig is spherical, it deforms into an elliptical shape. As a result, the gap between the inner wall surface of the pipe and the outer surface of the pig increases, and the lining film becomes thicker.

On the other hand, when the pressure difference ΔP is reduced and the moving speed of the pig is reduced, the resistance force of the lining material applied to the pig is reduced, and the elastic deformation of the pig is also reduced. As a result, the gap between the pipe inner wall surface and the pig outer surface is reduced, and the lining coating becomes thinner.

(Example) Hereinafter, an example of the present invention will be explained in detail based on FIGS. 1 and 2.

Fig. 1 is an implementation system diagram of the first embodiment of the present invention. working fluid,
3 is a flow rate/pressure regulator, 4 is an exhaust device such as a vacuum pump,
5 is a lining material, 6 is an elastic material pig, 7 is a lining material supply valve, and 8a.

8b is a lining material discharge valve, 9 is a firing device, 10 is a recovery device, 11 is a lining material receiving tank, 12 is a lining material discharge tank, and 13.14 is a control valve.

When lining the inner wall surface of the pipe, if the pipe to be treated 1 is an existing pipe, the pipe is first divided into appropriate lengths of about 30 to 500 m, and the inlet end 1a and outlet end 1b are opened.

Next, connect each device as shown in FIG.
A predetermined amount of lining material 5 is stored in the valves 7, 8a,
8b and 13 are closed.

After that, the exhaust device 4 is activated to reduce the pressure inside the treated tube 1,
When the pipe internal pressure is reduced to a set value, the valve 7 is opened and the lining material in the tank 11 is sucked into the space in front of the pig 6. Since the lining material is a highly viscous fluid as will be described later, it accumulates in layers to block the inside of the pipe, as shown in FIG.

The lining material 5 has excellent layer storage properties and is highly viscous (40
The most suitable material is a liquid or gel-like material with a range of 00 to 8 QOOOCPS), which has good fluidity, has little sag, and has the necessary properties (corrosion resistance, safety, etc.) as a lining material. Specifically, epoxy resin paints with high viscosity (the sag limit thickness of the coating film is in the order of 0.5 to 5) and high viscosity cement-based lining materials are most suitable.

In this example, the lining material 5 was coated with an epoxy resin paint (working fluid temperature 25°C) with a sag limit thickness of 5.
It is used as.

The pig 6 is made of a flexible and deformable soft elastic material such as rubber or plastic, and its outer diameter is selected to be slightly smaller than the inner diameter of the object to be treated 'R1. The pig 6 is used to flow the highly viscous lining material 5 forward, and as described later, the pig 6 is used to flow the highly viscous lining material 5 along the pipe wall with the working fluid 2 while maintaining a predetermined gap between the pipe wall and the pipe wall. Pressed forward.

In this embodiment, the pig 6 is a solid ball made of elastic plastic, but a hollow ball made of rubber,
Alternatively, it may be a hollow rubber ball filled with fluid to inflate it.

The amount of lining material 5 to be sucked into the pipe to be treated 1 is calculated from the length of the pipe, the thickness of the coating to be formed, the diameter of the pipe, etc., and is usually 1.1 to 1.2 of the required calculation amount. About twice the amount of lining material 5 is suctioned.

In this embodiment, the pig 6 is inserted into the firing device 9 before suctioning the lining material 5, but the pig 6 is inserted after a predetermined amount of the lining material 5 has been suctioned. Of course, it is possible.

Further, in this embodiment, the exhaust device 4 is connected to the end of the tube to be treated 1, but if the tube to be treated 1 has a branch pipe, the exhaust device 4 may be connected to this.

When suction of the required amount of lining material 5 is completed, valves 7 and 1 are closed.
4 is closed, valves 8 and 13 are opened, and the flow rate/pressure regulator 3 is adjusted to supply the working fluid 2 at a predetermined flow rate and pressure into the pipe, and the lining material 5 is injected into the pipe via the pig 6. is advanced toward the outlet end 1b at a predetermined speed. When the pig 6 and the lining material 5 accumulated in a plug shape inside the pipe flow in the direction of the arrow, a lining film 5a having a substantially constant thickness is formed on the inner wall surface of the pipe, and when the thickness of the lining film 5a is increased. increases the flow rate and pressure of the working fluid and increases the moving speed of the pig 6.

That is, when the speed of the pig 6 is increased, the resistance force of the highly viscous lining material 5 applied to the pig 6 increases, and the pig 6 deforms from its original shape with a circular cross section to a rough pole shape with an elliptical cross section. As a result, the gap between the inner wall surface of the pipe and the outer surface of the pig increases, resulting in the formation of a thicker coating film.

When the pig 6 reaches the collection device 10, the remaining lining material 5 is discharged into the tank 12, and the entire inner wall surface of the tube to be treated 1 is completely lined.The working fluid 2 to be supplied into the tube As the gas, a gas such as air or nitrogen, water, etc. can be used, and in this embodiment, compressed air from a compressor is used.

According to the test results, the temperature of the working fluid 2 is 40 to 45°C;
When the atmospheric temperature is 20~25℃, the flow rate of lining material 5 (sagging limit thickness 5WN epoxy resin paint) is U = & 3~30m/min, the thickness of the pipe is 50~600 mm, A coating film thickness of 1 to 4 mm could be obtained.

In this embodiment, the pig 6 is pressed by the working fluid 2, but the exhaust device 4 reduces the pressure in the space in front of the lining material 5, and creates a pressure between the space in front of the pig 6 and the space behind the pig 6. It is also possible to generate a difference and cause both to move forward.

Further, although one pig 6 is used in this embodiment, a plurality of pigs 6 may be connected by a flexible string. In the case of the pig having the above configuration, the outer surface of the lining film formed on the inner wall surface of the pipe is shaped by the rear pig, resulting in a film with a smoother outer surface.

(Effects) (1) By reducing the pressure inside the pipe to be treated using the exhaust device, a predetermined amount of lining material is sucked into the pipe, so the lining material supply system needs to be cleaned every time the supply of lining material is completed. This greatly improves lining work efficiency.

(2) A pig made of elastic material is inserted into the pipe, and the lining material is pushed forward through the pig, so its shape changes depending on the speed of movement of the pig, and the coating thickness decreases. Change.

As a result, by changing the moving speed of the pig, 0.5
A coating film having any thickness in the order of 4 to 4 can be formed on the inner wall surface of the pipe.

(3) Since the pipeline is closed with the lining material, the required flow rate of working fluid is significantly reduced compared to the previous lining method, resulting in a significant reduction in energy consumption and a reduction in the supply of working fluid. The capacity of the device can be reduced, and large-diameter pipes can be easily lined.

(4) At curved portions of the pipeline, the flow resistance of the lining material applied to the pig increases, and the amount of deformation of the pig increases. As a result, the coating thickness at the curved portion increases, and the level difference on the inner wall surface of the pipe at the curved portion becomes smaller, which is advantageous.

(5) When moving the lining material using an exhaust device, the supply of the lining material into the pipe to be treated and the lining treatment of the inner wall surface of the pipe can be performed using one exhaust device, and the lining treatment can be performed using one exhaust device. This invention is advantageous in terms of cost reduction.As mentioned above, the present invention has excellent practical utility.

[Brief explanation of the drawing]

FIG. 1 is an implementation system diagram of an embodiment of the present invention. FIG. 2 is an explanatory diagram of a conventional liquid phase lining construction method. 1 Pipe to be treated 2 Working fluid 3 Flow rate/pressure regulator 4 Exhaust device 5 Lining material 6 Elastic material pig 11 Lining material tank

Claims (4)

[Claims] (1) By reducing the pressure inside the tube to be treated (1), the highly viscous lining material (5) is suctioned and a layer of the lining material (5) is accumulated at the inlet end of the tube to be treated (1), A pig (6) made of elastic material provided behind the lining material (5)
A pressure difference ΔP is generated between the rear space of the lining material (5) and the front space of the lining material (5), and the lining material (5) and the pig (6) are directed together toward the outlet end of the pipe to be treated (1). A method for lining an inner wall surface of a pipe, characterized in that the inner wall surface of a pipe is moved. (2) A method for lining an inner wall surface of a pipe according to claim 1, wherein the pressure difference ΔP is generated by reducing the pressure in the space in front of the pig (6). (3) The working fluid (2) is supplied from the rear of the pig (6) to generate a pressure difference ΔP.
The method for lining the inner wall of a pipe as described in Section 1. (4) The method for lining an inner wall surface of a pipe according to claim 1, wherein the pig (6) is a telescopic pig filled with fluid and inflated.