JP2016107424A - Method for lining existing piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for lining the inner surface of existing piping, where the method performs lining with good energy efficiency in a cold period and a cold place at low temperature.SOLUTION: The method includes a first step for allowing an assembly 3a of ultraviolet light-emitting diodes 3 with good luminous efficiency to move into a lining material 2 to irradiate it with ultraviolet light, and a second step for allowing an auxiliary heating body 4 with a high calorific value to move in the lining material to rise the temperature of the lining material and curing it.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for lining the inner surface of an existing pipe using a lining material impregnated with a photocurable resin.

Conventionally, as a lining method for existing piping, a tubular lining material impregnated with an uncured photo-curing resin is introduced into the inner surface of the existing piping, and the outer periphery is brought into close contact with the piping by pressurized gas. The lining material is cured by irradiating light from the inner surface of the material with a light irradiation device.
The lining material used in the photo-curing lining method is generally made by impregnating a glass fiber braid with a photo-curing resin (for example, vinyl ester resin, unsaturated polyester resin, epoxy resin, etc.). used.

Here, the photocurable resin is generally cured by a radical polymerization reaction by ultraviolet irradiation. At that time, since the polymerization reaction does not occur easily, a photoinitiator is usually added to cause the reaction.
The photopolymerization initiator is activated by absorbing light and causes reactions such as cleavage reaction, hydrogen abstraction, and electron transfer. By this reaction, a substance that initiates the reaction (active starter substance) such as radical molecules and hydrogen ions is generated.
The generated active starting material attacks the resin molecular chain to cause a three-dimensional polymerization or cross-linking reaction. When this reaction results in molecules of a certain size or more, the light irradiated part changes from a liquid state to a solid state and is cured.

When lining a main pipe having a relatively large diameter, a method of curing a resin of the lining material by connecting a plurality of UV lamps of about 1000 W in series as a light irradiation device and irradiating the light is performed. It was.
Further, when the diameter of the pipe is small, such as a branch pipe, UV curing of about 150 W is connected in series to perform photocuring of the lining material.
These light irradiation devices are provided with wheels in the radial direction so that the lamp body is held on the central axis inside the lining material and can be moved. ).

  In this case, the ultraviolet lamp moved from the upstream side to the downstream side of the pipe at a moving speed of 15 to 20 cm / min. The wavelength of the irradiated light is 365 to 400 nm, and the wavelength of the much irradiated light is 365 nm. And it was necessary to adjust the photoinitiator of a photocurable resin so that it might match the wavelength of the light.

Apart from that, there were cases where a plurality of UV LED aggregates were connected instead of UV lamps and introduced into the photocurable resin. In this case, the wavelength of the ultraviolet LED light used was 385 nm, and it was necessary to adjust the photoreaction initiator of the photocurable resin material according to the wavelength.
Therefore, the photoreaction initiator in the case of using an ultraviolet lamp was different from the photoinitiator of the lining resin in the case of using an ultraviolet LED.

  Next, Patent Literature 1 below proposes “a photocuring method of a photocurable lining material and a photocuring system used in the method”. First, an infrared lamp is used as a heating element, and a lining material preliminary step for preheating the tubular lining material is provided to raise the temperature of the surface of the annular lining material. Thereafter, light curing is performed by an ultraviolet LED to cause photocuring.

Japanese Patent No. 4964015

  As a general photocurable resin, a resin that starts and cures when irradiated with ultraviolet light is used. The optimum temperature condition for the curing reaction of the photo-curing resin is 120 ° C to 140 ° C. When the surface of the lining material is processed without reaching this temperature, the durability of the lining material after processing, such as the hardness and bending strength May be impaired.

When multiple UV lamps are connected to cure the lining material, the amount of light emitted is about 20% of the power consumption, and the remaining 80% was used for heat generation (see Table 1). The exothermic temperature is 200 ° C to 300 ° C. The moving speed of the ultraviolet lamp inside the lining material is 15 to 20 cm / min.
In this case, the power consumption is extremely large, and the moving speed, that is, the curing speed is low. Furthermore, since the amount of heat generation is large, the lining material may be burned, and there is a drawback that temperature management is difficult.

Next, in the case of lining with an ultraviolet LED, the light emission amount accounts for 80% of the electric power, and the heat generation amount is 20%. The heat generation temperature becomes 80 to 140 ° C., and the moving speed inside the lining material can be increased to 40 cm / min. In recent years, LEDs with good irradiation efficiency have been produced at low cost, and there have been many attempts to increase the number of LEDs and efficiently perform lining work.
However, in the winter when the air temperature is 10 ° C or lower, or when cold water such as groundwater flows into the pipe, it is absorbed by the lining material even if the heat generation temperature of the UV LED is 80 to 140 ° C. The heat is immediately taken away and the surface temperature of the lining material becomes about 90 ° C. In this case, the optimum temperature for the curing reaction is not reached, and it may be extremely difficult to perform photocuring with only the ultraviolet LED.

  Next, it has been clarified that the method of heating the lining material with an infrared lamp in advance and curing the lining material by irradiating the LED with light as in the cited document 1 is not effective depending on the conditions. That is, according to the experiment of the present inventor, even if the lining material is heated in advance with an infrared lamp, in the cold season or in a pipe where cold water enters the existing pipe, the existing lining material is immediately installed from the heated lining material. It was found that heat was transferred to the piping side, the temperature could not be raised to the effective curing temperature of the lining material, and sufficient hardness could not be given to the lining material even when irradiated with LED light.

In the invention described in Patent Document 1, there is no specific example of the process, and the reproducibility of the construction method remains unclear. For example, in this method, the temperature is first raised in the preheating step, and the temperature is raised to a temperature at which the photocuring reaction is good. However, it is unclear to what extent the conditions for improving the photocuring reaction are.
Specifically, it has been impossible for those skilled in the art to know how many times the temperature of the lining material is increased with an infrared lamp to improve the curing of the LED in the next step by light irradiation.

  Therefore, as a result of various experiments, it is an object of the present invention to provide a method for lining existing pipes that is safe, quick, and consumes less energy even under conditions of low air temperature.

The present invention described in claim 1 introduces a tubular uncured photo-curing lining material (2) to the inner wall of the existing pipe (1), and irradiates light from the inside of the lining material (2). In the lining method for existing piping that hardens the lining material,
Subsequent to the assembly (3a) of the ultraviolet LED (3) located on the tip side, an auxiliary heating body (4) having higher heat generation than the ultraviolet LED is connected, and the assembly of the ultraviolet LED (3) (3a) and the auxiliary heater (4) are turned on simultaneously, and they are moved in the lining material (2),
First, by the assembly (3a) of the ultraviolet LED (3) located on the tip side, the lining material (2) is irradiated with ultraviolet rays to maintain at least the surface of the lining material at 90 ° C. or higher,
Next, in this state, the lining material (2) is heated by the auxiliary heating element (4) on the rear end side, and the temperature of at least the surface of the lining material (2) is raised to 110 ° C. or more to obtain a lining material. This is a lining method for existing piping that is to be cured.

According to a second aspect of the present invention, in the lining method for an existing pipe according to the first aspect,
The auxiliary heating body (4) is an existing piping lining method in which any one of an ultraviolet lamp, an infrared lamp, a visible light lamp, a visible light LED, an infrared LED, or a combination of one or more thereof is used.

In the lining method of the existing pipe of the present invention, first, an assembly of ultraviolet LEDs having high luminous efficiency on the tip side is moved in the lining material, and the lining material is irradiated with ultraviolet light to at least the surface of the lining material. Maintain above 90 ℃,
Next, in this state, an auxiliary heating body with high exothermicity is moved in the lining material, and at least the surface of the lining material is heated to 110 ° C. or more to cure the lining material.

  In this way, by first irradiating light with a highly luminescent UV LED, the UV energy starts the initial reaction of the lining material (formation reaction of the active starting material) and at the same time, highly exothermic auxiliary heating Reheat to 110 ° C or higher, which is the appropriate temperature for the curing reaction of the lining material (radical polymerization reaction with the resin material by the active initiator material) by the body. Increase the chance of collision with the chain). By this step, the lining material can be cured more efficiently than before.

  And the range of the reheating temperature in the auxiliary heating body at that time can be made comparatively narrow, and the whole energy consumption can be made small. That is, the total power of the power used by the UV LED with good light efficiency and the power used by the auxiliary heater with good heat generation can be reduced as much as possible. At the same time, the entire curing time can be shortened and lining can be performed quickly.

Further, the curing method of the invention according to claim 2 increases the versatility of the photo-curing material.
That is, this method, particularly when an ultraviolet lamp is used as an auxiliary heater, quickly cures any material, whether it is a photocuring material dedicated to an ultraviolet lamp or a photocuring material dedicated to an ultraviolet LED. And piping lining.
Furthermore, even when cold water enters cold piping or when existing water enters the existing piping, the auxiliary heating element is simultaneously reheated, so that temperature efficiency is high and the lining material can be cured reliably.

Explanatory drawing of the lining method of the existing piping of this invention. Explanatory drawing of the hardening experiment by the same method. Explanatory drawing of the experimental apparatus of the 1st process of the method. Explanatory drawing of the experimental apparatus of the 1st process of the method.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram of the existing pipe lining method of the present invention.
In this example, an existing pipe 1 as a main pipe is disposed between a pair of manholes 10 and 10 and the inside of the pipe 1 is lined for repair. Therefore, the lining material 2 is introduced into the pipe 1, and pressurized air is introduced into the inside thereof so that the lining material 2 is brought into close contact with the inner wall of the pipe 1. This lining material 2 contains a tubular and uncured photo-curing resin material.
This photo-curable resin material causes an initial reaction (generation reaction of an active starting material) by irradiating light including ultraviolet rays. However, the temperature at which this reaction proceeds best is 120 ° C to 140 ° C (the optimum temperature for the polymerization reaction of the resin material). Below this temperature, the number of unreacted parts increases and the lining material has sufficient hardness. I can't.

  Next, an assembly 3 a of a plurality of ultraviolet LEDs 3 and an ultraviolet lamp 4 a as one or more auxiliary heaters 4 are connected in series in the lining material 2. In this example, the auxiliary heating body 4 is arranged on the upstream side of the pipe 1, and the aggregate 3a of the ultraviolet LEDs 3 is connected to the downstream side thereof (in FIG. 1, the left side is the upstream and the right side is the downstream). And the guide cable 7 is connected with them, and the cable 7 is moved in the arrow direction from the left to the right in the figure. Wheels 5 are provided at appropriate positions in the radial direction, so that the ultraviolet LED 3 and the main body portion of the auxiliary heating body 4 are held at the center position in the radial direction of the lining material 2.

Therefore, each ultraviolet LED 3 of the assembly 3a existing on the downstream side in the moving direction is turned on, and simultaneously, the upstream ultraviolet lamp 4a is turned on. Then, they are moved from upstream to downstream of the lining material. First, the inner surface temperature of the lining material is set to 90 ° C. to 100 ° C. by irradiation with the ultraviolet LED 3 (initial stage of the curing reaction: formation reaction of the active starting material). Next, the lining material is reheated by the upstream ultraviolet lamp 4a, and the inner surface temperature is set to 120 ° C. to 140 ° C., whereby the lining material is cured.
At this time, the number of aggregates 3a of ultraviolet LEDs 3 and the number of connected ultraviolet lamps 4a as auxiliary heaters 4 are selected according to the inner diameter of the pipe 1. Further, the number of ultraviolet LEDs 3 included in the aggregate 3a is also determined as appropriate.
As an example, when the existing piping is a sewage main, the number of ultraviolet LEDs 3 included in the aggregate 3a can be 500 or more. Further, the wattage of the ultraviolet lamp 4a can be set to 1000 W as an example.

  As an example, the wavelength of the ultraviolet LED 3 may be 385 nm. The wavelength of the ultraviolet lamp 4a can be 365 nm to 400 nm, for example. The inner surface of the lining material 2 is heated to at least 90 ° C. or more as the connected body of the aggregate 3a moves.

Next, FIG. 3 and FIG. 4 and Table 2 explain experimentally the operation and effect of the lining method of the present invention.
(Experiment 1)
In FIG. 3, a glass plate 9 is arranged on the surface side of a rectangular lining material 2 having a thickness of 3 mm and a length and width of 10 cm, and a stainless steel plate 8 is arranged on the back side (Method A, Method C and Method D in Table 2). . The glass plate 9 and the stainless steel plate 8 (thickness 1.0 mm) have the same shape as the lining material 2. At that time, the temperature on the front side and the back side of the lining material 2 is measured by a thermometer.
An aggregate 3a of ultraviolet LEDs 3 is disposed 10 cm above the glass plate 9. Twenty-four UV LEDs 3 having a wavelength of 385 nm are arranged in parallel on the plane.

Next, in the case of FIG. 4, a heat insulating material 11 (thickness 10.0 mm) is arranged on the back side of the lining material 2 instead of the stainless steel plate 8 of FIG. 3 (Method B in Table 2).
After irradiation with ultraviolet rays, the hardness of the lining material was measured (measured with a Barcol hardness meter after 60 minutes of curing reaction) and the color state was visually observed.
Experiment 1 shown in Table 2 was performed at a room temperature of 20 ° C.
In the experiments of the A method, the C method, and the D method, the stainless steel plate 8 is used instead of the existing piping under the low temperature condition. The purpose of the experiment using the heat insulating material 11 of the method B is to confirm whether or not an appropriate temperature of the lining material can be obtained if there is no heat absorption from the back side.
In the experiment of the method A and the method D, hot air of 140 ° C. to 180 ° C. was blown for 3 minutes instead of the auxiliary heating body.
In each of the A method, the B method, the C method, and the D method, the lining material 2 was irradiated with the ultraviolet LED 3 for 5 minutes.

The result of Experiment 1 will be described.
First, in the method B, the surface temperature of the lining material 2 after irradiation with the ultraviolet LED 3 for 5 minutes was 120 ° C. to 130 ° C. At this time, the back surface temperature of the lining material was 21 ° C. In Method B, a light yellow color, which is a standard for curing the color of the lining material, was confirmed, and the hardness of the lining material was 20 to 40, and an acceptable rigidity could be obtained.
In the method B, since the back surface of the lining material is a heat insulating material, all the radiant heat is absorbed by the lining material, so that it can be assumed that the lining material has a high temperature and the curing reaction has proceeded efficiently.

On the other hand, in the method C, the surface temperature of the lining material 2 after irradiating the ultraviolet LED 3 for 5 minutes was 100 ° C., and the back surface temperature at this time was 20 ° C. In the method C, the lining material was uncured (color was transparent), and its hardness was 0 (hardness measurement with a Barcol hardness tester was impossible).
It is considered that the curing reaction hardly occurred because the synchrotron radiation was absorbed as heat by the stainless steel plate.

Next, the method A will be described.
Method A is the same as method C, in which lining material 2 is irradiated with ultraviolet LED 3 for 5 minutes, the surface temperature is heated to 100 ° C, and immediately after that air at 140 ° C to 180 ° C is sprayed for 3 minutes with a dryer. . As a result, the surface temperature of the lining material 2 increased from 100 ° C. to 120 ° C. The back side temperature is 21 ° C. And the hardness at that time was 20-40, and the resin material discolored to light yellow.

Next, method D is a method proposed as a prior art, and is described in Patent Document 1 (Patent No. 4964015), which is a “photocuring method of a photocurable lining material and a photocuring system used in the method”. It is an invention.
The difference between the D method and the A method is that the lining material 2 is heated before the irradiation of the ultraviolet LED. A simple experiment of this D method was conducted by the following method. First, a dryer (blowing temperature 140 ° C. to 180 ° C.) was blown into the lining material 2 from the upper surface side of the glass plate 9 for 3 minutes and heated, and immediately after that, ultraviolet LED irradiation was performed for 5 minutes. As a result, the surface temperature of the lining material 2 finally became 100 ° C., the temperature on the back surface side was 20 ° C., and the hardness of the lining material 2 at that time was 0, and measurement with a Barcol hardness meter was impossible. Its color is transparent.

From the results of Experiment 1 (Table 2), the following became clear.
When the back side material of the lining material 2 is a stainless steel plate, when the lining material 2 is heated after ultraviolet LED irradiation as in the method A, the surface temperature of the lining material 2 can be sufficiently increased and the lining material 2 can be cured.
This is because, by first irradiating the ultraviolet LED, a production reaction of many active initiators occurs, and then, by raising the temperature, the radical polymerization reaction between them and the molecular chain of the resin material can be promoted. It is considered that the curing reaction is efficiently performed.
However, when the lining material 2 is first heated as in method D, the surface temperature of the lining material 2 does not eventually exceed 100 ° C., and it is photocured (to obtain an acceptable strength). It was found that it was not possible.
Contrary to method A, since the temperature is raised without causing the reaction to generate the active initiator, the radical polymerization reaction itself does not occur when the temperature is raised, and heat is applied to the back surface material after the temperature rise is stopped. It is considered that the polymerization reaction is unlikely to occur even when the reaction field temperature is lowered and the ultraviolet ray is irradiated thereafter to generate the active initiator.

In the following Experiment 2, Experiment 3, Experiment 4, and Experiment 5, the results obtained in Experiment 1 are supported by a fume tube.
Next, FIG. 1 shows a lining material 2 in which a lining material 2 is inserted into a pipe 1 having an inner diameter of 150 mm and a length of 5000 mm, and an ultraviolet lamp 4a and an assembly 3a of ultraviolet LEDs 3 are connected in series as an auxiliary heating body 4. Two curing experiments were performed. At this time, the number of the aggregates 3a of the ultraviolet LEDs 3 is four (144 LEDs in one aggregate 3a), and the ultraviolet lamp 4a is connected to 150 W (one unit). The temperature of the piping was as low as 5 ° C.

(Experiment 2)
Experiments 2 and 3 were performed by connecting the auxiliary heating body 4 to the succeeding group 3a of the ultraviolet LEDs 3 as shown in FIG.
In Experiment 2, only the ultraviolet LED 3 of the assembly 3a was turned on, and it was moved in the direction of the arrow from the left end, which is the upstream side of the lining material 2, toward the right end. The moving speed at this time is 40 cm / min. At this time, the temperature of the pipe 1 was at a low temperature of 5 ° C.
The inner surface temperature of the lining material 2 due to the movement of only the aggregate 3a of the ultraviolet LED 3 was 100 ° C., the hardness of the lining material was 0, it was a transparent color, and sufficient strength could not be obtained.

(Experiment 3)
Next, in the low temperature state where the temperature of the pipe is 5 ° C., the ultraviolet LED 3 of the assembly 3a is turned on and the ultraviolet lamp 4a of the auxiliary heater 4 is turned on. Moved in min.
In this case, the surface temperature of the lining material 2 was 120 ° C. to 130 ° C., the lining material 2 was cured (the color was light yellow), and its hardness was 20 to 40, and sufficient strength could be obtained.

(Experiment 4)
Next, Experiment 4 and Experiment 5 are comparative experiments with Experiment 3.
As described in Patent Document 1, first, the ultraviolet lamp was turned on and moved from the left end of the pipe 1 to the right end at a moving speed of 40 cm / min. Immediately thereafter, the ultraviolet LED 3 was turned on and moved from the left end of the pipe 1 to the right end at a moving speed of 40 cm / min.
The result was the same as in Experiment 2. The inner surface temperature of the lining material 2 was 100 ° C., and the hardness of the lining material was 0, which was a transparent color, and sufficient strength could not be obtained.

(Experiment 5)
Next, the experiment was performed by reversing the arrangement of the ultraviolet lamp 4a and the assembly 3a of the ultraviolet LEDs 3 from that of Experiment 3. That is, the ultraviolet lamp 4a is located on the front end side in the moving direction, the assembly 3a of the ultraviolet LEDs 3 is arranged on the trailing end of the ultraviolet lamp 4a, both are turned on simultaneously, and the moving speed is 40 cm from the left end of the pipe 1 to the right end. It moved at / min.
The result was the same as in Experiment 2. The inner surface temperature of the lining material 2 was 100 ° C., and the hardness of the lining material was 0, which was a transparent color, and sufficient strength could not be obtained.

That is, the following can be said in the lining method of existing piping under a low temperature condition using a photocurable resin.
Experiments 4 and 5 are preheated with an ultraviolet lamp. At this time, the amount of the active starting material generated is small by the ultraviolet irradiation of the ultraviolet lamp, and even when heated to 120 ° C. in this state, the reaction efficiency is poor and the curing is insufficient, and the lining material obtained by heating is heated. The heat is immediately taken away by the existing piping, and it is difficult to reach a temperature suitable for the curing reaction of the lining material. Since the ultraviolet LED 3 is turned on thereafter or immediately after that, it can be assumed that the curing reaction hardly occurs.
As shown in the supporting experiment 3 of the present invention, the lining material is heated to 90 ° C. by the assembly 3a of the ultraviolet LED 3 and sufficient UV irradiation is performed to advance the generation reaction of the active starting material. And then reheating to 120 ° C to 140 ° C, which is the optimum temperature for radical polymerization of the resin material (to facilitate the initial reaction between the molecular chain of the resin material and the active initiator) It was found that the curing reaction can be efficiently promoted.
It can be seen that in order to obtain this effect, it is necessary to connect the auxiliary heating body 4 to the rear of the assembly 3a of the ultraviolet LEDs 3.

  In these embodiments, the auxiliary heater 4 has been described as the ultraviolet lamp 4a. However, instead of this, a known infrared lamp, visible light lamp, visible light LED, or infrared LED may be used. Furthermore, these can also be used in combination.

1 Piping 2 Lining material 3 UV LED
3a aggregate 4 auxiliary heater 4a ultraviolet lamp 5 wheel 6 end 7 guide cable 8 stainless steel plate 9 glass plate 10 manhole 11 heat insulating material

Claims (2)

Introducing a tubular, uncured photo-curing lining material (2) to the inner wall of the existing piping (1), and irradiating light from the inside of the lining material (2) to cure the lining material. In the method
Subsequent to the assembly (3a) of the ultraviolet LED (3) located on the tip side, an auxiliary heating body (4) having higher heat generation than the ultraviolet LED is connected, and the assembly of the ultraviolet LED (3) (3a) and the auxiliary heater (4) are turned on simultaneously, and they are moved in the lining material (2),
First, by the assembly (3a) of the ultraviolet LED (3) located on the tip side, the lining material (2) is irradiated with ultraviolet rays to maintain at least the surface of the lining material at 90 ° C. or higher,
Next, in this state, the lining material (2) is heated by the auxiliary heating element (4) on the rear end side, and the temperature of at least the surface of the lining material (2) is raised to 110 ° C. or more to obtain a lining material. Lining method for existing pipes to be cured. In the lining method of the existing piping according to claim 1,
A method for lining an existing pipe, wherein the auxiliary heater (4) is one of an ultraviolet lamp, an infrared lamp, a visible light lamp, a visible light LED, an infrared LED, or a combination of one or more thereof.

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