JPH0580337B2 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for lining the inner surface of a pipe, which can be advantageously implemented in an exhaust stack or the like that guides exhaust gas from a combustion device that burns gaseous fuel, liquid fuel, or the like.

Background Art The exhaust gas generated from such combustion equipment contains trace amounts of SOx, NOx, chlorine gas, water vapor, and the like. They may be present in combustion air and fuel, or may be produced by combustion. As a result, water vapor condenses into water droplets in the exhaust stack, which dissolves SOx and chlorine gas, producing sulfuric acid and hydrochloric acid. These are reducing acids that corrode exhaust pipes made of stainless steel, SUS304, etc., creating holes and causing exhaust gas to leak, resulting in accidents. Further, condensed water leaks from the hole formed by the corrosion, and when the exhaust pipe is installed on a ceiling indoors, the ceiling becomes dirty.

In order to prevent such corrosion of the exhaust tube, a paint layer is formed on the inner peripheral surface of the exhaust tube, or the lining tube is lined with an adhesive.

Problems to be Solved by the Invention In such prior art, the paint layer and lining layer peel off from the inner peripheral surface of the exhaust stack when the exhaust stack reaches a high temperature of, for example, 180°C during use. This causes a new problem in that the inside of the exhaust pipe is blocked. Furthermore, when forming a lining layer inside the exhaust stack, pressure is maintained within the lining layer until the adhesive interposed between the outer circumferential surface of the lining layer and the inner circumferential surface of the exhaust stack hardens. Therefore, the construction time is long.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved method for lining the inner surface of a pipe, such as an exhaust stack, which does not cause blockage of the pipe to be lined and allows the lining work to be performed easily. be.

Means for Solving the Problems The present invention temporarily lines the inside of the pipe to be lined with a lining tube by an inverted lining method, and the outer diameter of the lining tube in its natural state is larger than the outer diameter of the pipe to be lined. Reduce the diameter of a large coil spring, pull its tip in the axial direction of the lining tube, insert it, release the tension, and use the elastic force of the coil spring outward in the radial direction to insert the temporarily lined lining tube into the tube. This is a method for lining the inner surface of a pipe, characterized by pressing the inner peripheral surface of the pipe.

Effect According to the present invention, the lining tube, which is temporarily lined inside the pipe to be lined by the inversion lining method, is pressed against the inner circumferential surface of the pipe by the radially outward elastic force of the coil spring. ing. The lining tube therefore does not sag radially inward. Therefore, the flow path within the lining tube will not be blocked. Moreover, when the adhesive is interposed between the outer circumferential surface of the lining tube and the inner circumferential surface of the tube, the coil spring presses the lining tube against the inner circumferential surface of the tube as described above. As mentioned in connection with this, there is no need to maintain pressure within the lining tube, and therefore the construction work is simple and the work time is shortened.

The coil spring is inserted into the lining tube while its tip is pulled while the diameter is reduced.
The diameter of the coil spring remains reduced, making it easy to insert it, and when the tension is stopped, the coil spring returns to its natural state, and the elastic force in the radial direction pulls the lining tube into the inner circumference of the tube. Since the lining tube is pressed against the surface, the lining tube will not be crushed and the cross-sectional area of the flow path will not become small, especially at the bent portion of the tube.

Embodiment FIG. 1 is a sectional view of an embodiment of the present invention.
The pipe 5 to be lined is an exhaust pipe that guides exhaust gas from combustion equipment, and is made of stainless steel, for example.
Made of SUS304 etc. A lining tube 6 is inserted into this tube 5. The outer diameter of the lining tube 6 is approximately equal to or slightly larger than the inner diameter of the tube 5. A coil spring 7 is inserted into the lining tube 6, and this coil spring 7 presses the lining tube 6 against the inner circumferential surface of the tube 5 with a radially outward elastic force. In this way, the lining tube 6 is kept in contact with the inner peripheral surface of the tube 5. Therefore, the lining tube 6 will not sag inward in the radial direction, and the cross-sectional area of the exhaust gas flow path in the lining tube 6 will not become small and will not become clogged. When an adhesive is interposed between the outer circumferential surface of the lining tube 6 and the inner circumferential surface of the tube 5, the lining tube 6 is pressed against the inner circumferential surface of the tube 5 by the action of the spring 7.
Adhesion is ensured. Therefore, as described in connection with the prior art described above, there is no need to maintain pressure within the lining tube 6 until the adhesive hardens, resulting in good workability.

The lining tube 6 is made of materials such as fluororesin, nylon, and polyethylene terephthalate. The coil spring 7 may be made of fluororesin, or may be made of a corrosion-resistant metal such as titanium, Hastelloy, or seawater-resistant stainless steel, or may be coated with a heat-resistant resin on the outer peripheral surface of a metal wire. Furthermore, the outer peripheral surface of the metal wire may be coated with a cylindrical body of heat-resistant resin.

FIG. 2 is a sectional view showing the working steps of the embodiment shown in FIG. A lining tube 6 is inserted into the tube 5 by being reversed. One end 6a of the lining tube 6 is fixed to the end 5a of the tube 5. As shown by the arrow 8 from the end 5a side of the tube 5, the lining tube 6 inverts and enters the tube 5 due to the pressure of gas such as air and other fluids, thereby causing the tube to close. The lining tube 6 is temporarily lined over the entire length of the tube 5.

Next, as shown in FIG. 2, a coil spring 7 is prepared and housed in a right cylindrical cylindrical body 9. The outer diameter of the coil spring 7 in its natural state is that of the tube 5.
It is selected to be larger than the outer diameter D1 of the cylindrical body 9, and much larger than the inner diameter D2 of the cylindrical body 9.

A locking portion 10 is formed at the end of the cylindrical body 9 and projects radially inward. The inner diameter of this locking part 10
D3 is smaller than the inner diameter D2 of the cylindrical body 9, and prevents the coil spring 7 from jumping out from the cylindrical body 9 in a natural state. When the end 7a of the coil spring 7 is pulled, the diameter of the coil spring 7 becomes smaller and the locking part 1
It becomes smaller than the inner diameter D3 of 0 and is pulled out of the cylindrical body 9. This is pulled in the axial direction of the lining tube 6 (to the right in FIG. 2) as shown by the arrow 11, and inserted into the lining tube. In this case, the diameter of the coil spring 7 is the inner diameter of the locking part 10.
Since it has a smaller diameter than D3, it can be smoothly inserted into the lining tube 6 without coming into contact with the inner peripheral surface of the lining tube 6. Coil spring 7 is lining tube 6
By releasing the tensile force of the coil spring 7 while the coil spring 7 is inserted over the entire length of the coil spring 7,
presses the lining tube 6 against the inner circumferential surface of the tube 5 by its radially outward elastic force. In this way, the state shown in FIG. 1 is reached, and the inner circumferential surface of the tube 5 is fully lined with the lining tube 6. Furthermore, at the bent portion of the tube 5 shown in FIG. 3, the lining tube 6 is temporarily lined and a space 20 is created between it and the tube 5, but the coiled spring 7 presses it to the position of the imaginary line 21. The main lining has a sufficient cross-sectional area of the flow path.

In the present invention, there is no need for an adhesive to be interposed between the outer circumferential surface of the lining tube 6 and the inner circumferential surface of the tube 5. The pipe 5 may be an exhaust stack of a combustion device, or may be a pipe for transporting city gas or water, or may be a pipe used for other purposes.

Effects As described above, according to the present invention, a lining tube is temporarily lined using the reverse lining method, and then the coil spring, which has an outer diameter larger than the outer diameter of the tube, is stretched in a natural state so as to maintain the reduced diameter state. Since it is inserted into the lining tube, insertion work is easy. Next, by stopping the tension, the coil spring returns to its natural state and the lining tube is pressed against the inner surface of the tube to form the main lining, so that the lining tube hangs radially inward and the flow path There is no risk of the cross-sectional area becoming small or clogging. Therefore, the fluid can be transported reliably. This is especially true for
When the present invention is implemented in connection with an exhaust stack, even if the lining tube is damaged due to high temperatures or the like, the damaged portion is prevented from sagging radially inward. In addition, when a pipe is underground, there is a hole in the pipe, and even if water enters through the hole and water pressure acts on the lining tube in the radial direction, the lining tube's radially inward Displacement is prevented by a coil spring.

In addition, since the lining tube is elastically pressed against the inner circumferential surface of the tube by the coil spring, even when adhesive is interposed between the outer circumferential surface of the lining tube and the inner circumferential surface of the tube, As mentioned in connection with the above-mentioned prior art, the present invention does not require maintaining the pressure inside the lining tube, and can be used for fluid transport immediately after lining construction, resulting in good workability. At the same time, construction time is shortened. Further, the present invention does not require an adhesive, and by omitting the adhesive, workability is further improved.

When the tube has a bend, the bend also
The coil spring can be permanently lined by expanding the temporarily lined lining tube radially outward and in close contact with the inner circumferential surface of the tube.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view showing the working process of the present invention, and FIG. 3 is a sectional view of a tube with a bent portion. 5...Tube, 6...Lining tube, 7...
Coil spring, 11...Arrow mark indicating tension direction.

Claims (1)

[Claims] 1 Temporarily line the inside of the pipe to be lined with a lining tube using the inverted lining method, reduce the diameter of a coil spring whose outer diameter in its natural state is larger than the outside diameter of the pipe to be lined, and line the tube. It is characterized by inserting the tube by pulling its tip in the axial direction of the tube, releasing the tensile force, and pressing the tentatively lined tube against the inner peripheral surface of the tube by the radially outward elastic force of the coil spring. A method for lining the inner surface of pipes.