JPS5813226B2 - Lining method for pipe inner wall surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a method for lining the inner wall surface of a water supply and drainage pipe after grinding of scales, etc., and involves forming a mixed fluid of compressed air and paint into a hollow inverted conical shape. This invention relates to a method for lining the inner wall surface of a pipe, in which a lining film of uniform thickness can be formed with a small amount of air and without wasting paint by spraying the air onto the inner wall surface of the pipe.

The applicant previously proposed that compressed air and paint 5, as shown in FIG.
A method was developed in which a mixed gas A was injected from one end of the buried pipe 9, and the inner wall surface was coated with a constant thickness of paint. This is published as.

That is, the base resin 2 of the two-component mixed epoxy resin pressurized by the lining machine 1 and the curing liquid 3 are mixed in the mixer 4 to form the paint 5, and the paint 5 is supplied to the accelerated injection device 6 and then injected into the compressor 7. The mixed gas A is mixed with compressed air 8 from the lining pipe 9 and injected inward from one end of the pipe 9 to form a paint film of a constant thickness on the inner wall surface of the pipe.

In FIG. 1, 10 is a processing device for the discharged mixed gas, 11 is a dryer, 12 is a regulator, 13 is a flow meter, and 14 is a flow rate regulating valve.

As a result, the paint particles in the mixed gas A injected into the pipe 9 repeatedly come into contact with the pipe wall, and thereby gradually adhere to the inner wall surface of the pipe.

The paint particles adhering to the inner wall surface of the pipe become liquid and layered one after another, and the mixed fluid A continues to be press-fitted into the pipe.
The particles are successively swept away toward the outlet side, thereby forming a lining film on the inner wall surface of the pipe.

However, in the conventional construction method, the mixed gas A of paint and air is released over the entire cross section of the pipe to be lined 9, so in large-diameter pipes, the mixture A of paint and air flows through the center. Paint particles in mixed gas A are difficult to adhere to the pipe wall,
As a result, a large amount of paint 5 is contained in the exhaust gas discharged from the end of the pipe to be lined 9, resulting in considerable paint loss.

Furthermore, processing of the exhaust gas requires a lot of effort and expense.

Furthermore, since the mixed gas A is blown in parallel to the inner wall surface of the pipe, the kinetic energy of the paint particles in the direction perpendicular to the wall surface is small, and the adhesion force of the paint particles to the inner wall surface of the pipe is extremely weak.

As a result, the paint adhering to the top wall of the pipe tends to drip downward, making it difficult to form a paint film with a uniform thickness all around the inner wall of the pipe, and causing damage to the curved pipe. The disadvantage is that this becomes especially noticeable.

Furthermore, if the diameter of the pipe to be lined 9 increases, the amount of mixed fluid flowing through the center of the pipe will increase, and this will not work effectively to wash away the paint adhering to the pipe wall, resulting in a larger amount of mixed gas. This has the drawback of requiring a large capacity pressurized air source.

The present invention aims to eliminate the above-mentioned drawbacks in this type of pipe inner wall lining method, and has a relatively low loss of paint, even for large-diameter pipes with many bends. The object of the present invention is to provide a method for lining the inner wall surface of a pipe, which can form a paint film of uniform thickness over a considerable distance with a small volume of high-pressure air.

Hereinafter, the details will be explained based on the embodiments of the present invention shown in FIGS. 2 and 5.

FIG. 2 is a schematic diagram showing a first embodiment of the lining method according to the present invention, and FIG. 3 is a schematic cross-sectional view of a mixed fluid injection device used therein.

Referring to FIGS. 2 and 3, an epoxy resin paint 5 formed by mixing a predetermined amount of a base agent 2 and a curing agent 3 in a mixer 4 is processed by a lining machine 1 with a
It is pressurized to 50 kg/cm2 and is discharged in the form of a spray into the pressurized injection device 6 through a nozzle (not shown).

Compressed air of about 5 to 10 kg/cm<2> is fed into the pressurized injection device 6, and the two are sufficiently mixed to form a mixed gas A.

Mixture A was introduced into the injection pipe 1 at a pressure of approximately 5 to 8 kg/cm2.
5 and is supplied to the mixed fluid injection device 16, where the mixed fluid is changed into a hollow inverted conical shape and sprayed onto the inner circumferential wall surface of one end of the pipe 9 to be lined.

Note that the paint concentration in mixed fluid A is usually 0.1 to 0.2k.
It is adjusted to about g/m3.

The paint particles in the mixed fluid A sprayed onto the tube wall adhere to the tube wall surface and form a liquid paint layer B thereon.

The paint layer B is sequentially swept forward by the mixed fluid A that is subsequently injected, and after being swept away, the paint particles in the mixed fluid A that is subsequently injected are further layered, and this is the lining made of the previous paint. By being swept along the surface and moving forward, the lining surface gradually advances forward.

When the lining surface reaches the end of the pipe 9 to be lined, the inner surface of the transparent detection tube 17 attached to the end of the pipe 9 is also lined, thereby detecting the completion of lining and stopping the injection of the mixed fluid. do.

Usually, the pipe diameter to which this method can be applied is about 25A to 800A, and a lining film with a thickness of 0.5 to 1 mm can be formed at a lining speed of 0.5 to 1.5 m/min.

Referring to FIG. 3, the mixed fluid injection device 16 is composed of a nozzle body 16a, a horn body 16b, a guide body 16c, etc., and the mixed fluid A passes between the horn body 16b and the guide body 16c. , which is released to the outside in the form of a hollow inverted cone.

The position of the guide body 16c can be adjusted in the front-rear direction, thereby adjusting the spread angle α and the discharge film thickness C of the mixed fluid A discharged in a horn shape.

In this example, the mixed fluid A is at a constant angle α with the pipe wall.
Since the particles collide with each other, the paint particles can adhere extremely strongly to the pipe wall.

Once the paint layer B has strongly adhered to the pipe wall, the mixed fluid A continues to be injected without causing any drooping.
As a result, it is smoothly and reliably swept forward along the tube wall surface.

That is, the paint layer B is extremely uniformly formed with a substantially constant thickness t over the entire inner circumference of the pipe, and since the entire paint layer B is integrally swept forward at approximately the same speed, the thickness is extremely uniform. A lining film can be formed over the entire inner wall surface of the pipe.

Compared to conventional construction methods, the length of the pipe to be treated can be increased by 20 to 30%.

In addition, since the mixed fluid A is blown into the inner wall surface of the pipe with a hollow inverted conical shape, the kinetic energy of the air flow in the mixed fluid A can be used extremely effectively to sweep away the paint layer B. , there is less wasted airflow, and the amount of air required is reduced accordingly.

The reduction rate of air amount compared to the conventional construction method is about 30 to 40%.

Furthermore, since the mixed fluid A is injected in the shape of a hollow inverted cone, paint particles are approximately 90 to 95% sure to adhere to the tube wall, significantly reducing paint loss.

FIG. 4 shows another example of the mixed fluid injection device used in carrying out the present invention, and FIG. 5 is an explanatory diagram showing the situation of ejecting mixed fluid A when the injection device is used. .

In FIGS. 4 and 5, 18 is a cylindrical cover, and 19 is an inlet for accelerating air or a mixed fluid of paint and compressed air.

The inlet port 19 is installed so as to discharge fluid in the tangential direction of the circular inner circumferential surface of the cover unit 18, and the fifth inlet port 19
As shown in the figure, a constant angle α is maintained with respect to the central axis A.

A paint press-in tube 20 is inserted from the rear of the cover unit 18, and is supported so as to be movable in the front-back direction.

Further, a paint spray noise 21 is fixed to the tip of the press-in tube 20, and the paint is discharged in the form of a spray in a direction perpendicular to the central axis through the spray hole 22.

Reference numeral 23 denotes a guide body, which is movably fixed by a nut 25 to the tip of a support bolt 24 whose one end is fixed to the injection nozzle 21.

When paint is injected from the injection nozzle 21 and compressed air is added from the inlet port 19, the mixed fluid of paint and air performs a swirling motion within the cover unit 18, and the mixed fluid A flows into a hollow space as shown in FIG. It has the shape of an inverted cone, and it is sprayed while rotating in a fixed direction.

Normally, a mixed fluid A in which paint 5 and compressed air 8 are mixed in advance is blown into the inlet port 19, and the mixed fluid A is formed into a hollow inverted conical shape that makes a swirling motion in the same way as described above and is lined. It is used by spraying onto the inner wall of the pipe 9.

Due to the swirling motion of the mixed fluid injected into the pipe wall, the paint layer B adheres and is laminated on the inner wall surface of the pipe to be lined 9.
The particles do not travel in a straight line along the tube wall, but instead move forward in a gentle spiral motion.

As a result, the thickness of the lining film formed on the inner circumferential wall of the pipe becomes even more uniform, and the paint laminate B is swept forward extremely smoothly, eliminating any unevenness, and reducing the amount of compressed air. It is possible to achieve a significant reduction in

In this embodiment, the paint laminate B is pushed forward by the kinetic energy seen by the mixed fluid A, but pressurized gas is injected into the lined pipe 9 from the rear as an auxiliary measure. Of course, this is a good thing.

As mentioned above, the present invention has excellent practical utility in that it can form a lining film with an extremely uniform thickness even in long-distance piping with many curves, using less compressed air and less paint. It is something.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a conventional method of lining the inner wall surface of a pipe with a mixed gas. FIG. 2 is a schematic explanatory diagram of the lining method according to the present invention. FIG. 3 is a sectional view of a mixed gas injection device used in the present invention, and FIG. 4 is a sectional view of another type of mixed gas injection device. FIG. 5 is a perspective view showing the injection situation of the mixed gas injection device. A: Mixed fluid, B: Paint layering, 5
...Synthetic resin paint, 6 ... Acceleration injection device, 8 ... Compressed air, 9 ... Lined pipe, 10 ... Exhaust gas treatment device, 15
...Injection pipe, 16...Mixed fluid injection device, 16a...Nozzle body, 16b...
Horn body, 16c...Guide body, 17...
...Detection tube.

Claims (1)

[Claims] 1. A synthetic resin paint 5 is mixed with compressed air 8 to form a mixed fluid A, and the mixed fluid A is injected into the inner wall surface of one end of the pipe to be lined 9 in the form of a hollow inverted cone. , the paint particles in the mixed fluid A are attached to the inner wall surface of the pipe to sequentially form a liquid paint layer B, and the paint layer B is gradually pushed forward along the inner wall surface of the pipe by the mixed fluid A injected into the pipe. A distinctive method for lining the inner wall of pipes. 2. The method for lining an inner wall surface of a pipe according to claim 1, wherein the mixed fluid A is injected in a hollow inverted conical shape that makes a swirling motion.