JPH0242553B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an improvement in a method for lining the inner wall surface of a pipe, and is suitable for the rehabilitation of relatively large-diameter buried gas pipes, buried water pipes, etc., and the manufacture of lined pipes. It is something that is used.

(Conventional technology) To rehabilitate buried gas pipes or water pipes, sandjet flow (mixed fluid of abrasive material and air flow) is passed through the pipe to clean the inner wall surface of the pipe, and then the inner wall surface of the pipe is coated with epoxy resin paint, etc. The lining method is generally widely used.

The method of lining the inner wall surface of the pipe with paint or the like is to suspend paint particles in a conveying air flow, pass the mixed fluid through the pipe at high speed, and apply paint to the inner wall surface of the pipe during the flow. A method of forming a coating film on the inner wall surface of a pipe by causing particles to adhere evenly (Japanese Patent Application Laid-Open No. 156046/1983,
127941, etc.), a mixed fluid of paint and air flow is supplied into the pipe, paint particles are deposited and laminated on the inner wall surface of the pipe inlet, and the paint layer deposited and laminated on the inner wall surface of the pipe is applied to the inside of the mixed fluid. A method in which a coating film is formed on the inner wall surface of the pipe by moving the air forward sequentially using
-24195 Publication, Special Publication No. 58-13226, etc.),
Two elastic objects (pigs) are placed at a distance in the pipe, and after filling the space between the two elastic objects with paint, the two elastic objects are moved forward with the paint sandwiched between them by fluid pressure, etc. Methods such as forming a coating film on the inner road wall surface (Japanese Unexamined Patent Publication No. 55-44320, etc.) have been widely used for some time.

The above methods and methods are all excellent construction methods, and are actually widely put into practical use for rehabilitation of pipelines in buildings, factories, etc.

However, these methods still have many problems that need to be solved. For example, in the above method,
Paint losses are high due to the large amount of paint particles in the mixed fluid discharged from the end of the tube. 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 the above method, it is extremely difficult to make the coating thickness on the inner wall of the pipe 1 mm or more.
When it comes to large-diameter pipes of 4B or more, the amount of air required increases and a large-capacity compressor is required, so there are restrictions from this point of view, and the thickness of the coating on the curved part (elbow part) is smaller than that of the straight pipe part. Problems remain, such as the fact that it is extremely thin compared to the previous version.

On the other hand, although the above-mentioned method is an excellent method when applied to a relatively large-diameter pipe line, there are still problems to be solved. In other words, a liquid paint with low viscosity is filled between the two elastic pigs, and in order to move them inside the pipe as a unit by fluid pressure, etc., the rear pig adheres to the inner wall of the pipe. The paint peeled off or was scraped off, making it difficult to form a lining film of 1 mm or more even on straight pipes. The lining film on the inner wall surface of the curved part becomes particularly thin because it is scraped off considerably. ○Since the two pigs with the lining material sandwiched between them slide as one, their sliding properties are extremely poor and the diameter is small. It cannot be used for pipelines or pipelines with many bends, and because the lining material is scraped off by the pig at the rear, the lining film thickness does not change much even if the moving speed of the pig is changed. Problems such as difficulty in adjustment remain.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems in the conventional lining of the inner wall of a pipe of this type. It is difficult to increase the film thickness, and it is difficult to apply it to large-diameter pipes from the viewpoint of work efficiency, paint loss, and securing an air supply source. This method attempts to solve problems such as 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. All types of pipelines from small diameters to large diameters can be manufactured with high efficiency without the need for large capacity fluid supply equipment, with a relatively thick coating thickness of 1 to 1.5 mm or more, and pipelines including elbow parts. 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 to a uniform thickness.

(Means for Solving the Problems) The present invention involves inserting an elastic sliding body into a pipe to be treated, and injecting a highly viscous fluid lining material behind the sliding body to The inside of the pipe is almost closed, and then a pressure difference △P is generated between the front and back of the lining material, and the pressure difference △P
The basic structure of the invention is to form a lining film on the inner wall surface of the pipe by moving the lining material and the sliding body.

(Function) The sliding body inserted into the pipe and the lining material injected to block the pipe are moved one after another at a constant speed due to the pressure difference △P between the front and back of the lining material. A lining film is formed on the inner wall surface of the pipe through which the lining material has passed. The thickness of the lining film formed is determined by the moving speed and viscosity of the lining material, and the film thickness is controlled by controlling the moving speed.

As a lining material, it has a relatively high viscosity and “sags”.
The best material is one that has a low amount of fluid and has fluidity. Further, as the sliding body, it is preferable that it has elasticity and has low frictional resistance with the inner wall surface of the pipe.

After the lining film is formed, the film is dried by ventilation or the like, and the inside of the pipe is of course thoroughly cleaned before the lining treatment.

(Example) The present invention will be specifically described below based on an example of the present invention shown in FIGS. 1 to 3.

FIG. 1 is an implementation system diagram of the present invention, and FIG. 2 is an explanatory diagram of coating film formation. In the figure, 1 is a pipe to be treated such as a gas pipe, water pipe, or fixed length pipe, 2 is a fluid pressurizing device such as a compressor or pump, 3 is a pressure regulator, 4 is a flow meter, and 5 is a Inlet flow rate adjustment valve, 6
is an outlet flow rate adjustment valve, 7 is a lining material discharge valve, and 8 is a lining material discharge valve.
is the lining material in the tank, 9 is the lining material tank, 10 is the lining material injected into the pipe,
11, 12, 13 are valves, 14 is a pressure regulator,
15 is a sliding body made of an elastic material.

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

Next, connect each device as shown in Figure 1, and
The sliding body 15 is inserted inward from the open end of the sliding body 15, and the valve 11 is opened to inject the lining material 10 to the rear of the sliding body 15. The lining material 10 has excellent layer accumulation properties, is a highly viscous liquid or gel, has fluidity, has little sagging, and has the characteristics necessary for a lining material (corrosion resistance, safety, etc.). The best option is Specifically, high-viscosity (10,000 to 40,000 cps) epoxy resin paints and high-viscosity cement-based lining materials are most suitable.

In this embodiment, an epoxy resin paint having a viscosity of about 30,000 cps is used as the lining material 10.

The sliding body 15 is made of a flexible and deformable soft elastic material such as rubber or plastic, and its outer diameter is selected to be approximately the same as the inner diameter of the tube 1 to be treated. The sliding body 15 is intended to prevent the highly viscous lining material 10 from sagging forward, and presses it forward along the pipe wall while maintaining a slight frictional resistance between it and the pipe wall. will be moved.

The amount of lining material 10 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 10 is injected. still,
A necessary amount of lining material is injected into the pipe so that the lining material 10 is accumulated in the pipe as shown in FIG. 1 and the pipe is closed. At this time, it is convenient if the valve 13 is opened to slightly pressurize the inside of the lining material tank 9, since the lining material 10 can be injected more smoothly.

When the injection of the required amount of lining material 10 is completed, the inlet flow rate adjustment valve 5 is adjusted to supply the pressurized fluid A into the pipe, and the outlet flow rate adjustment valve 6 is adjusted and opened, so that the rear of the lining material 10 and the sliding body are adjusted. Due to the pressure difference ΔP between the lining material 10 and the front side of the lining material 15, the lining material 10 injected into the pipe is advanced toward the outlet end 1b at a predetermined speed. As the pressurized fluid A supplied into the pipe, gases such as air and nitrogen, water, etc. can be used, and in this embodiment, compressed air from a compressor is used.

When the pressurized fluid A is supplied into the pipe, the lining material 10 injected into the pipe and accumulated in a plug shape flows in the direction of the arrow as shown in FIG. A lining film 10b having a substantially constant thickness t is formed. At this time, since the sliding body 15 exists in front of the lining material 10, even if it is a large diameter pipe (for example, 5B to 15B), the lining material 10 will sag forward and the differential pressure between the front and rear of the lining material 10 will be reduced. There is no loss of ΔP, and the lining material 10 can be moved extremely smoothly in the state shown in FIG. 2.

According to the test results, lining material 10 (viscosity
30000cps, flow rate of epoxy resin paint) U = 3
When the speed is ~30m/min, the pipe diameter is 50~600mm,
A coating film thickness of t=4 to 1 mm can be obtained,
Also, the pressure difference △P between the front and back of the lining material 10 is 1
~4Kg/ ^cm2 .

In this embodiment, as shown in FIG. 1, the flow rate regulating valves 5 and 6 provided at the inlet side 1a and outlet side 1b of the pipe to be treated 1 are adjusted so that the flow rate on the lining material 10 moving inside the pipe is adjusted. - By adjusting the pressure difference between the downstream sides, the moving speed is controlled, and thereby the thickness of the coating film formed is controlled. However, the moving speed of the lining material 10 can be adjusted by any method, for example, by opening the outlet side and adjusting the flow rate or pressure of the pressurized fluid A applied from the inlet side, or by adjusting the flow rate or pressure of the pressurized fluid A applied from the inlet side. Of course, a method of adjusting the flow rate of the fluid on the outlet side while keeping the pressure constant may also be used.

Further, a suction device such as a vacuum pump may be provided at the outlet end 1b of the tube to be treated 1, and the lining material 10 and the sliding body 15 may be sucked and moved by the suction device, or the pressurized fluid A may be The supply of water and suction by a suction device may be used together.

Furthermore, in the embodiment described above, the required amount of lining material 10 is injected at once into the inlet end 1a of the tube to be treated 1, but as shown in FIG. 15 is carried out in multiple steps, and a plurality of lining materials 10a,
10a... may be made to proceed at the same time.
In the case where the lining material can be injected into the main pipe and the sliding body can be taken in and out from the middle of the pipe, for example, from multiple branch pipes, a plurality of lining materials 10a, 10a, etc. and the sliding body can be inserted into the main pipe as shown in Fig. 3. 15a, 15
By moving the pipes a... at the same time, extremely long pipes can be treated at once.

(Effects of the Invention) In the present invention, a sliding body is inserted into a pipe, and a highly viscous lining material is injected behind it.
The lining material that has blocked the pipe is moved at a predetermined speed by the pressure difference between the front and back, so even with large diameter pipes, the lining material sags forward and the lining material is There is no loss of differential pressure ΔP, and the lining material can be moved extremely smoothly.

In addition, when pressurized fluid A is used, the required flow rate of pressurized fluid A is significantly reduced compared to the conventional lining method, resulting in a significant reduction in energy consumption and a reduction in the size of the fluid pressurizing device. Capacity can be increased and lining of large diameter pipes becomes easier.

Furthermore, since a high viscosity lining material is used and a space is provided behind the lining material, a relatively thick coating film of approximately 1 to 5 mm in thickness can be easily formed on the inner wall surface of the pipe. The coating thickness does not change at all even at curved portions of the pipe, and a uniform and thick lining film can be formed over the entire length of the pipe.

Moreover, since only one sliding body is used,
Even though the viscosity of the lining material is much higher than in previous pigging methods, the lining material and the sliding body can be moved very smoothly.

Furthermore, by adjusting the pressure difference between the upper and lower reaches of the lining material flowing in the pipe and changing its movement speed, the coating film thickness can be easily controlled, even on large diameter pipes or small diameter pipes. Even if it is a diameter pipe, it is possible to reliably form a lining film of a predetermined thickness, and
It becomes possible to improve the mechanical strength of the pipe by utilizing the thickness of the formed coating film.

In addition, even for large-diameter pipes, it is sufficient to inject the amount of lining material necessary to form a film into the pipe inlet end, so there is almost no loss of lining material and economical lining is possible. becomes.

[Brief explanation of drawings]

FIG. 1 is an example of an implementation system diagram of the present invention,
FIG. 2 is an explanatory diagram of coating film formation. FIG. 3 is an explanatory diagram showing an example of injection of another lining material. 1... Pipe to be treated, 10... Lining material, 10
b...Lining film, 15...Sliding body, △P...
...pressure difference, A...pressurized fluid.

Claims (1)

[Scope of Claims] 1. Inserting an elastic sliding body 15 into the pipe to be treated 1, and injecting a highly viscous fluid lining material 10 behind the sliding body; The interior of the pipe to be treated 1 is substantially closed, a pressure difference ΔP is generated between the front and rear of the lining material 10, and the lining material 10 and the sliding body 15 are made to flow due to the pressure difference ΔP. A method for lining an inner wall surface of a pipe, which comprises forming a lining film 10b on the wall surface. 2. The method for lining an inner wall surface of a pipe according to claim 1, wherein the pressure difference ΔP is generated by the pressurized fluid A supplied from one side of the lining material 10. 3. The 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 inner space of the pipe on one side of the lining material 10. 4. According to claim 1, the pressure difference ΔP is generated by supplying the pressurized fluid A from one side of the lining material 10 and reducing the pressure in the space on the other side of the lining material 10. A method of lining the inner wall of a pipe. 5. A method for lining an inner wall surface of a tube according to claim 1, wherein the sliding body 15 is inserted from a plurality of locations in the tube 1 to be treated, and the lining material 10 is injected. 6 While keeping the pressure of the pressurized fluid A supplied to one side of the lining material 10 constant,
The method of lining an inner wall surface of a pipe according to claim 1, wherein the pressure difference ΔP between the front and rear of the lining material 10 is adjusted by adjusting the flow rate of the fluid discharged from the other side. 7. The method for lining an inner wall surface of a pipe according to claim 1, wherein the lining material 10 is a high-viscosity epoxy resin lining material.