JPS634885A - Lining method for inside wall surface of pipe - Google Patents

Abstract

PURPOSE:To surely form a uniform lining film having a prescribed thickness by inserting a pig made of an elastic material into a pipe and pushing and moving a lining material forward by such pig. CONSTITUTION:The high-viscosity lining material (e.g., epoxy resin paint having 0.5-5mm threshold thickness of the sag of a coated film) is accumulated in the pipe 1 to be treated and the pig 6 made of the elastic material is disposed behind the same. A prescribed flow rate of working fluid 2 (e.g., compressed air) is supplied into the pipe 1 from the rear of the pig 6 to move the material 5 forward. More specifically, the coated film having an arbitrary thickness between 0.5-5mm can be formed on the inside wall surface of the pipe by regulating the flow rate of the working fluid to change the moving speed of the pig. The uniform lining film having the prescribed thickness is surely formed even with a large- or small-diameter pipe by controlling the flow rate of the working fluid in the pipe to the constant value.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement in a method for lining the inner wall surface of W, and is used for rehabilitation of buried gas pipes and water pipes, and for manufacturing lined pipes.

(Conventional technology) To rehabilitate buried gas pipes and water pipes with relatively small diameters, a mixed fluid of abrasive material and conveying gas is jetted into the pipes to clean the inner walls of the pipes, and then epoxy paint or the like is applied. A method of lining the inner wall of pipes is widely used.

Therefore, the method of lining the inner wall surface of the pipe with the above-mentioned epoxy resin paint, etc. is as follows: (1) Dye particles are suspended in the airflow for dispersion, and the mixed fluid is passed through the pipe at high speed, and during the flow, it is applied to the inner wall surface of the pipe. A method of forming a paint film by colliding and adhering paint particles (JP-A-54-156046, JP-A-54-127941, etc.), ■Paint and m
Supplying a mixed fluid with the feeding airflow into the pipe to adhere and layer paint particles on the inner wall surface of the pipe inlet, and sequentially flow the adhered and layered paint layer forward by the conveying airflow in the mixed fluid, Method of forming a coating film on the inner wall surface of a pipe (Special Publication No. 58-2
4195 Publication, Special Publication No. 58-13226, etc.),
■Two pigs are placed in the pipe at a distance, and after filling the space between the two pigs with paint, the two pigs are moved forward with the paint held between them by fluid pressure, etc., to form a paint film on the inner wall of the pipe. Methods such as those disclosed in Japanese Unexamined Patent Publication No. 55-44320 and the like have been widely used.

All of the above methods (■, ■, and ■) are excellent construction methods, and are actually widely used in the rehabilitation of pipes in buildings, factories, etc.0 However, these methods also have interlayer problems that need to be resolved. There are many left. For example, in method (2) above, since a large amount of paint particles are contained in the mixed fluid discharged from the end of the pipe,
The fee loss will be large. Furthermore, since it takes a long time to form a coating on a large-diameter pipe, it is difficult to efficiently form a thick coating, and there is also the problem that the coating on the elbow portion inevitably becomes thin.

In addition, with method (1) above, it is extremely difficult to make the coating thickness on the inner wall surface of the pipe more than 1 mm, and for large diameter pipes of 4B or more, the amount of gas required increases, making it difficult to achieve a large capacity. Problems remain, such as the need for a feeding device, which imposes restrictions, and the thickness of the coating film on curved portions being extremely thin compared to straight pipe portions.

Furthermore, method (2) above is an excellent method when applied to pipes with relatively large diameters, but there are still problems to be solved. Since the pipe is filled with a liquid paint with low corrosion resistance, if the gap between the pig and the inner wall of the pipe becomes large, paint may leak or drip.
Therefore, it is necessary to use an object with relatively little elastic deformation for the pig, and as a result, the paint adhered to the inner wall of the bent pipe is peeled off or scraped off by the rear pig, and the straight pipe part is Even if there is, it is difficult to form a lining film of 0.5- or more. The coating is particularly thin, and since two pigs sandwiching the θ lining material slide together as a unit, their sliding properties are extremely poor, and they cannot be used on small-diameter pipes or conduits with many curves. ■Because the lining material is scraped off by the rear pig, the lining film thickness does not change much even if the moving speed of the pig is changed, and problems such as difficulty in determining the E% of the film thickness remain. - way,
In order to solve the above-mentioned interstitial problem, the inventors of the present invention inserted a sliding body B into the tube A to be treated and at the same time inserted a highly viscous material behind the sliding body B, as shown in FIG. Injecting a fluid lining material C, closing the inside of the tube A to be treated with the lining material C, and supplying a pressurized fluid into the tube A to flow the lining material C. Banko developed a method for forming a lining film and published it as Japanese Patent Application No. 141257/1983.

That is, the sliding body B inserted into the pipe and the lining material C injected in a state that blocks the inside of the pipe are the same as the lining material C.
The lining material C is sequentially moved forward due to the pressure difference ΔP between the front and rear, and a lining film is formed on the inner wall surface of the pipe through which the lining material C has passed. The thickness of the lining film formed is determined by the moving speed and viscosity of the lining material C, and the film thickness is controlled by adjusting the moving speed and the lining material viscosity.

However, in the construction method shown in FIG. 5, the flow velocity of the lining material C is controlled to a predetermined value by keeping the pressure of the pressurized fluid tank at the pipe inlet constant. Since the flow resistance of the lining material C varies greatly depending on the condition of the pipe (the surface roughness of the pipe inner wall surface, the pipe diameter, the curvature of the curved part, the pipe length, the pipe temperature, etc.), its advancing speed pulsates significantly. As a result, in the case of pipes with many bends or long pipes,
Significant fluctuations occur in the thickness of the coating film formed on the inner wall surface of the pipe,
There is a problem in that the coating film thickness cannot be freely controlled in practice.

(7! Problem to be solved by the invention) The present invention solves the above-mentioned pressure in the lining of the inner wall surface of the pipe.
In other words, ■ With the method of using a mixed fluid of electrical transmission gas and lining material, it is difficult to increase the thickness of the coating on the inner wall of the pipe, and it is difficult to increase the thickness of the coating on the inner wall of the pipe, resulting in significant problems in terms of work efficiency, paint loss, and securing an air supply source. It is difficult to apply this method to diameter pipes. ■The method of moving the lining material sandwiched between two pigs is difficult to apply.
The lining film is extremely thin, it is almost impossible to control the film thickness, and it is easy to cause clogging accidents during work. This method aims to solve problems such as the drastic variation in coating film thickness and difficulty in controlling the coating thickness. With a relatively thick coating thickness of 0.5 to 5.0 mm, there is no need for a large-capacity fluid supply device.
Moreover, it is an object of the present invention to provide a method for lining the inner wall surface of a pipe, which makes it possible to line the entire length of the pipe including the elbow portion to a desired uniform thickness.

(Pause: Means for solving the origin) The present invention accumulates a layer of high-viscosity lining material inside the pipe to be treated, and arranges a pig made of an elastic material behind the lining material, and injects a specified amount into the pipe from behind the pig. The basic structure of the invention is to supply a flow rate of working fluid to move the lining material forward.

(Operation) The flow rate of the working fluid in the pipe is directly controlled to a predetermined value, and as a result, the pig and the lining material move forward at a substantially constant speed corresponding to the flow rate of the working fluid.

When the moving speed of the pig is increased by increasing the flow rate of the working fluid, 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 is deformed 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 coating becomes thicker.

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

By controlling the flow rate of the working fluid in the pipe and adjusting the moving speed of the pig, the gap between the pig and the inner wall of the pipe is changed, and a lining coating film of a desired thickness is formed on the inner wall of the pipe.

(Example) Hereinafter, the present invention will be specifically described based on an example of the present invention shown in FIGS. 1 to 4.

Figure 1 is book f7! i←This is an implementation system diagram of the invention, and Figure 2 is an explanatory diagram of coating film formation.In Figure 0, 1 is a gas pipe line;
These are pipes to be treated such as water pipes and fixed length pipes, 2 is a working fluid from a compressor or pump, 3 is a flow M regulator, 4 is a flow meter, 5 is a lining material 6 is a pig made of an elastic material. , 7 is a lining material supply valve, 8 is a lining material discharge valve, 9 and 1
0 is a connection unit.

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 m to 30 m, and the inlet end 1a and outlet end 1b are opened.

Next, connect each device as shown in FIG. The lining material 5 is injected.

The lining material 5 has excellent tank storage properties and is highly viscous (40
00-80,000CP S) (7) Liquid or gel-like tear has fluidity, has little sag, and has the characteristics necessary as a lining material (corrosion resistance, safety, etc.) is suitable for R. Specifically, epoxy resin paints with high viscosity (the sag limit thickness of the coating film is α5 to 5 mm) and high viscosity cement-based lining materials are most suitable.

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

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 tube 1 to be treated. The pig 6 is used to flow the highly viscous lining material 5 forward, and is pushed forward along the pipe wall by the working fluid 2 while maintaining a predetermined gap between it and the pipe wall. be done.

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 injected into the pipe to be treated 1 is calculated based on 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 injected. As shown in FIG. 1, a necessary amount of lining material is injected into the pipe so that a layer of lining material 5 is accumulated in the pipe and the pipe is closed.

When the injection of the required amount of lining material 5 is completed, the flow regulator 3 is adjusted to supply a predetermined flow rate of the working fluid 2 into the pipe, and the lining material 5 injected into the pipe via the pig 6 is maintained at a predetermined speed. to advance toward the exit end 1b. As the working fluid 2 supplied into the pipe, a gas such as air or nitrogen,
Water or the like can be used, and in this embodiment, compressed air from a compressor is used.

When the working fluid 2 is supplied into the pipe, the pig 6 and the lining material 5 injected into the pipe and accumulated in a plug shape flow in the direction of the arrow as shown in FIG.
A lining film 5a having a constant thickness t+ is formed.

In addition, in order to increase the thickness of the lining film 5a,
The flow rate of the drawing fluid is increased to increase the moving speed of the pig 6. That is, as shown in FIG. 2, when the speed of the pig 6 is increased, the resistance force of the highly viscous lining material 5 acting on the pig 6 increases, and the pig 6 changes from a spherical shape with a circular cross section to a rough shape with an elliptical cross section. Transforms into a ball shape. As a result, the gap between the inner wall surface of the pipe and the outer surface of the pig increases, and a thicker coating film having a thickness t2 is formed.

According to the test results, the temperature of the working fluid 2 is 40-45°C.
1 Atmospheric temperature 20-25°C 1 Sponge spherical pig, lining material 5 (sag limit thickness 5 mm, epoxy resin paint)
When the flow rate U = 0.3 to 377 Z/min, the thickness t = 1 to 5 rrr for a pipe with a diameter of 50 to 600 -
It was possible to obtain a coating film thickness of m.

FIG. 3 shows a second embodiment of the present invention, in which the inlet pressure of the working fluid 2 applied from the pipe inlet side 1 is kept constant, and the exhaust from the end opening 1b of the pipe 1 to be treated is By adjusting the flow rate using a flow meter 11 and a flow rate regulator 12, the flow rate of the working fluid 2 in the pipe is directly controlled at a predetermined level.

In addition, in Fig. 3, 13 is a lining material receiving tank;
4 is a pressure regulator.

FIG. 4 shows a third embodiment of the present invention.

In this embodiment, a plurality of pigs 6a and 6b are connected by a flexible connecting string 15, and the front pig 6a
mainly acts to push the lining material 5 forward,
Further, the rear pig 6b functions to shape the outer surface of the lining coating film adhered to the inner wall surface of the pipe. That is, the lining film formed on the inner wall surface of the pipe by the flow of the front pig 6a and the lining material 5 is pressed against the inner wall surface of the pipe by the rear pig 6b, thereby making the thickness of the coating film uniform and improving the coating film thickness. A smoothing of the outer surface is carried out.

(Effects of the Invention) ■ In the present invention, a pig made of an elastic material is inserted into the pipe, and the lining material is compressed and moved forward through the pig, so that the lining material is moved forward according to the moving speed of the pig. The shape changes, and the coating thickness changes accordingly. By adjusting the flow rate of the working fluid and changing the moving speed of the pig, a coating film having an arbitrary thickness of 0.5 to 5 - can be formed on the inner wall surface of the pipe.

■ Since the flow rate of the working fluid in the pipe is controlled to a constant value, there is almost no pulsation in the moving speed of the pig. As a result, a homogeneous lining film of a predetermined thickness can be reliably formed even on a large-diameter pipe or a small-diameter pipe.

■ Since the pipeline is closed with a 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 the reduction of the working fluid supply device. The capacity can be reduced,
Easy lining of large diameter pipes.

■ Because only one pig is used, the lining material and the pig can be moved extremely smoothly, even though the viscosity of the lining material is much higher than the previous method using two pigs. .

(2) 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 film thickness at the curved portion increases, and the coating film at the curved portion does not become extremely thin as in the conventional lining method.

■ When multiple pigs are connected, the outer surface of the coating film becomes even smoother.1. A lining coating film with no pinholes etc. is formed.

As mentioned above, the present invention has excellent practical utility.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention. FIG. 2 is an explanatory diagram of the state of formation of the lining coating film. FIGS. 3 and 4 are explanatory diagrams of other embodiments of the present invention. FIG. 5 is an explanatory diagram of the lining method previously developed by the inventor of the present invention. l Pipe to be treated 2 Working fluid 3 Flow rate regulator 4 Flow meter 5 Lining material 6 Elastic material pig 15 Flexible connecting cord patent applicant Osaka Gas Co., Ltd. Japan Technology Development Center Procedures Amendment (self-motivated) September 1, 1985 is the date of the incident.Special Application No. 1988-1 No. F763 No. 2,
Title of the invention: Method 8 for lining inner walls of pipes, relationship with the amended case Patent applicant address: 5-1 Hirano-cho, Higashi-ku, Osaka Name (
028) Osaka Gas Co., Ltd. Representative: Masafumi Onishi 4, Agent address: 5, Kitahama Chikaratano Building, 3-39 Kitahama, Higashi-ku, Osaka City, Number of inventions increased by amendment None 6, Subject of amendment: “Inventions” in the description "Detailed explanation" column "-
° de.

Claims (5)

[Claims] (1) High viscosity lining material (5) inside the pipe to be treated (1)
A pig (6) made of an elastic material is disposed behind the pig (6), and a predetermined flow rate of the working fluid (2) is supplied into the pipe (1) from behind the pig (6). Lining material (5)
A method for lining the inner wall surface of a pipe, characterized by moving the inner wall surface forward. (2) The inner wall surface of the pipe according to claim 1, wherein the flow rate of the working fluid (2) in the pipe is controlled to a predetermined value by adjusting the exhaust flow rate from the pipe to be treated (1). lining method. (3) Claim 1 in which the pig (6) is a plurality of pigs (6a) and (6b) connected by a flexible string.
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 thin film pig filled with fluid and inflated. (5) Lining material (5) with a viscosity of 4000 to 80.0
The method for lining an inner wall surface of a pipe according to claim 1, which uses a two-component epoxy resin paint of 00 CPS.