Method of stopping water in multiple structure

Abstract

To provide a method of stopping water in a multiple structure which method can be simply applied without identifying a place where water leak will be stopped.SOLUTION: A method of stopping water in a multiple structure includes a primary water stopping step of supplying a primary waterproof material 1 having water-absorbing properties to a space formed within an outermost shell S1 of the multiple structure S having a broken hole position X, and a secondary water stopping step of sealing the broken hole position X of the outermost shell S1 with a secondary waterproof material 2. The supply of the primary waterproof material 1 from the inside of the outermost shell S1 of the multiple structure S roughly stops water, and the secondary waterproof material 2 finishes stopping water.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a waterproofing method for a multi-layer structure, and more particularly to a waterproofing method for a multi-layer structure that is suitable for preventing water leakage from the outermost shell of the multi-layer structure. [Background technology]

[0002] Piping through which gases or liquids containing hazardous substances flow often has a multiple piping structure (e.g., double piping, triple piping, etc.). Tanks that store gases or liquids containing hazardous substances also often have a multiple partition wall structure (e.g., double partition wall, triple partition wall, etc.). Hereinafter, in this specification, the term "multiple structure" is meant to include both a multiple piping structure and a multiple partition wall structure.

[0003] If a hole occurs in the outermost shell of the multi-layer structure, water may leak from the hole. Since the water leaking from the hole may contain harmful substances, it is preferable to stop the water leaking.

[0004] For example, Patent Document 1 discloses an expansion joint used to connect pipes in nuclear power plants, and the portion where the expansion joint is installed generally has a multiple pipe structure. Furthermore, the invention described in Patent Document 1 is provided with a cover to prevent damage to the bellows of the expansion joint. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-96821 Summary of the Invention [Problem to be solved by the invention]

[0006] If water leaks from a multi-layered structure, possible water-stopping methods include spraying a fast-hardening resin such as polyurethane into the broken area, or constructing a dam in the broken area and filling it with a water-stopping material such as urethane rubber.

[0007] However, fast-curing polyurea has problems with the reliability of waterproofing. Also, when the bellows is covered with a cover, as in the invention described in Patent Document 1, for example, there is a problem that the location of the rupture cannot be identified, and the waterproofing material cannot be supplied directly to the ruptured area.

[0008] Furthermore, when the multi-layered structure is located in a place where people's entry and staying time are restricted, such as a nuclear power plant, the watertight work must be carried out by remote control, which poses the problem that the watertight work of constructing a dam and filling it with watertight material is difficult to carry out.

[0009] The present invention has been devised in view of the above problems, and aims to provide a waterproofing method for a multi-layer structure that can be easily performed without specifying the waterproofing location. [Means for solving the problem]

[0010] According to the present invention, there is provided a waterproofing method for a multi-layered structure, characterized by including a primary waterproofing process in which a water-absorbent primary waterproofing substance is supplied to a space formed inside the outermost shell of a multi-layered structure having a rupture, and a secondary waterproofing process in which the rupture in the outermost shell is sealed with a secondary waterproofing substance.

[0011] The primary water blocking material may be a water-absorbing polymer.

[0012] The secondary water-stopping material may be a hardening agent, and the secondary water-stopping step may be a step of supplying the hardening agent to the space to which the primary water-stopping material has been supplied.

[0013] The secondary waterproofing material may be a resin sheet, and the secondary waterproofing step may be a step of covering the outside of the outermost shell portion with the resin sheet.

[0014] The secondary waterproofing material may be a resin paint, and the secondary waterproofing step may be a step of applying the resin paint to the outside of the outermost shell portion.

[0015] The secondary water-stopping material may be a radiation-resistant water-stopping material.

[0016] The primary watertightness process and the secondary watertightness process may be performed by a remotely controlled robot. [Effects of the Invention]

[0017] According to the water-stopping method for a multi-layered structure of the present invention described above, a primary water-stopping process is carried out to supply a water-absorbent primary water-stopping substance to the rupture site from the inside of the outermost shell of the multi-layered structure, thereby reducing the gap at the rupture site, and sealing the rupture site with a secondary water-stopping substance, thereby effectively preventing water leakage from the rupture site. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is an explanatory diagram showing an overview of a waterproofing method for a multi-layer structure part according to one embodiment. FIG. [Figure 2] Figure 1 shows a conceptual diagram of the water-stopping method. (a) shows the state after the primary water-stopping material has been supplied, (b) shows the state after the primary water-stopping material has absorbed water and roughly stopped the water, and (c) shows the state after the secondary water-stopping material has been supplied to the space inside the outermost shell and the rupture has been sealed. [Figure 3] FIG. 10 is a side view showing a first modified example of the secondary waterproofing step. [Figure 4] FIG. 10 is a side view showing a second modified example of the secondary waterproofing step. [Figure 5] FIG. 10 is a side view showing a third modified example of the secondary waterproofing step. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 5. Fig. 1 is an explanatory diagram showing an outline of a waterproofing method for a multi-layer structure part according to one embodiment. Fig. 2 is a conceptual diagram of the waterproofing method shown in Fig. 1, in which (a) shows a state in which a primary waterproofing substance has been supplied, (b) shows a state in which the primary waterproofing substance has absorbed water and roughly sealed the water, and (c) shows a state in which a secondary waterproofing substance has been supplied to the space inside the outermost shell part and the broken part has been sealed.

[0020] The waterproofing method for a multi-layered structure part according to this embodiment includes, for example, a primary waterproofing process of supplying a water-absorbent primary waterproofing substance 1 to a space formed inside the outermost shell part S1 of the multi-layered structure part S having a rupture site X, as shown in Figures 1 to 2(c), and a secondary waterproofing process of sealing the rupture site X of the outermost shell part S1 with a secondary waterproofing substance 2.

[0021] The multi-structure portion S has, for example, a multi-piping structure as shown in the figure. Fig. 1 shows a double-piping structure in which an inner pipe S2 is arranged inside an outermost shell portion S1. The multi-piping structure portion is not limited to the configuration shown in the figure, and may be a multi-piping structure with three or more pipes, or a multi-wall structure such as a tank.

[0022] The outermost shell portion S1 is, for example, a bellows piping having a multi-piping structure. Note that the outermost shell portion S1 is not limited to a bellows piping, and may be another type of expansion joint or ordinary piping. Furthermore, although not shown, a bellows cover may be disposed on the outer periphery of the outermost shell portion S1 to prevent damage to the bellows.

[0023] The bellows piping that constitutes the outermost shell S1 is a component that absorbs expansion and contraction in the axial direction of the pipe due to temperature changes of the pipe. A certain space (gap) is formed between the outermost shell S1 and the inner pipe S2. If gas or liquid containing harmful substances flows through the inner pipe S2, there is a possibility that the harmful substances will be contained in water leaking from the outermost shell S1, and therefore it is preferable to suppress water leakage from the outermost shell S1.

[0024] At this time, it is conceivable to spray resin paint from the outside of the outermost shell S1, or to build a dam around the broken site X and fill it with a resin water-stopping substance. In this way, when approaching the broken site X from the outside of the outermost shell S1 to stop the water, problems arise such as the need to identify the broken site X, there being issues with the reliability of water-stopping using only resin paint, and the difficulty of construction by remote control.

[0025] Therefore, in order to solve these problems, the waterproofing method for the multi-layered structure part S according to this embodiment aims to waterproof the rupture site X by supplying a waterproofing substance from the inside of the outermost shell part S1 of the multi-layered structure part S.

[0026] The primary waterproofing step is a step of roughly waterproofing the broken portion X by supplying a primary waterproofing material 1 into the space formed inside the outermost shell portion S1 (the outermost space of the multi-structure portion S).

[0027] When supplying the primary waterproof material 1 to the space inside the outermost shell part S1, for example, a hole communicating with the space to which the primary waterproof material 1 is to be supplied is made in the outermost shell part S1, and a supply pipe 3 is connected to the hole. The supply pipe 3 may be connected to a plug pre-formed in the outermost shell part S1. A supply source 4 of the primary waterproof material 1 is connected to the end of the supply pipe 3, and a pump 5 is connected to the middle part of the supply pipe 3.

[0028] By supplying the primary water-stopping material 1 at a predetermined pressure into the space formed inside the outermost shell portion S1, the primary water-stopping material 1 can be made to reach the rupture site X, as shown in Fig. 2(a). Furthermore, if there is a flow of water leaking from the rupture site X, the primary water-stopping material 1 can be made to reach the rupture site X by being carried along with the water flow. For ease of explanation, particles of the primary water-stopping material 1 are shown enlarged in Figs. 2(a) to 2(c).

[0029] The primary water-stopping material 1 is, for example, a water-absorbent polymer such as an acrylic acid polymer. Therefore, as shown in FIG. 2(b), the particles that reach the rupture site X absorb the surrounding moisture and expand, filling the space inside the rupture site X with the primary water-stopping material 1. The expansion of the primary water-stopping material 1 reduces the gap through which water flows, weakening the water leakage pressure and achieving rough water-stopping. The primary water-stopping material 1 may also be a water-absorbent polymer that is radiation-resistant.

[0030] In this way, by supplying the primary water-stopping material 1 from inside the outermost shell part S1, even if the rupture site X cannot be identified, the primary water-stopping material 1 can be supplied to the rupture site X. For example, even if the bellows is covered by a bellows cover and the surface of the outermost shell part S1 cannot be visually observed, the primary water-stopping material 1 can be made to reach the rupture site X.

[0031] The secondary waterproofing process is a process for completing waterproofing by sealing the areas roughly waterproofed by the primary waterproofing material 1. In the embodiment shown in Fig. 2(c), this is a process for supplying a secondary waterproofing material 2 to the space to which the primary waterproofing material 1 has been supplied. For ease of explanation, the hardened state of the secondary waterproofing material 2 is shown in gray in Fig. 2(c).

[0032] When supplying the secondary waterproofing material 2, the supply equipment (supply piping 3, supply source 4 and pump 5) used when supplying the primary waterproofing material 1 may be reused, or supply equipment may be installed in a separate system.

[0033] The secondary waterproofing material 2 is, for example, a fast-curing curing agent. For example, a two-component sealant or a three-component sealant can be used as the curing agent. The secondary waterproofing material 2 may also be a radiation-resistant material (for example, epoxy resin). By using a radiation-resistant curing agent, deterioration due to radiation can be suppressed, and the material can be applied to multiple structural parts S of nuclear power plants and the like.

[0034] When the multi-layered structure S is located in a place where people are restricted from entering or staying for a long time, such as a nuclear power plant, it is necessary to perform the watertight work by remote control. In the above-described embodiment, as shown in Fig. 1, it is only necessary to install equipment for supplying the primary watertight material 1 and the secondary watertight material 2 to the space inside the outermost shell S1, and the work can be performed by a remotely controlled robot.

[0035] Next, modified examples of the secondary water stopping process will be described with reference to Fig. 3 to Fig. 5. Fig. 3 is a side view showing a first modified example of the secondary water stopping process. Fig. 4 is a side view showing a second modified example of the secondary water stopping process. Fig. 5 is a side view showing a third modified example of the secondary water stopping process.

[0036] In the modified secondary waterproofing process shown in FIGS. 3 to 5, the ruptured portion X is sealed from the outside of the outermost shell portion S1.

[0037] In the first modified example shown in Fig. 3, the secondary waterproofing material 2 is a resin sheet 21. In this case, the secondary waterproofing process is a process of covering the outside of the outermost shell portion S1 with the resin sheet 21. The resin sheet 21 is a sheet made of a material such as unsaturated polyester resin, glass fiber impregnated with visible light curable resin, polyethylene, polyester, butyl rubber, or the like.

[0038] Even when the first variant is adopted, the work simply involves wrapping or attaching the resin sheet 21 around the outer periphery of the outermost shell part S1 without identifying the rupture location X, so the work can be carried out by a remotely controlled robot.

[0039] In a second modified example of the secondary waterproofing process shown in Fig. 4, the secondary waterproofing material 2 is a resin paint 22. In this case, the secondary waterproofing process is a process of spraying and applying the resin paint 22 to the outside of the outermost shell portion S1. For ease of explanation, in Fig. 4, the cured state of the resin paint 22 is shown filled in gray.

[0040] The resin paint 22 is a paint made of, for example, urethane rubber, epoxy resin, vinyl ester resin, polyurea resin, etc. When radiation resistance is taken into consideration, epoxy resin, etc. can be selected as the resin paint 22.

[0041] The second modified example is effective when it is possible to identify the location of the rupture site X. Even when the second modified example is adopted, the work simply involves applying the resin paint 22 to the outer periphery of the outermost shell portion S1, and therefore the work can be carried out by a remotely controlled robot.

[0042] In a third modified example of the secondary waterproofing process shown in Fig. 5, the secondary waterproofing material 2 is a high-viscosity resin paint 23. In this case, the secondary waterproofing process is a process of applying the resin paint 23 dropwise to the outside of the outermost shell portion S1. For ease of explanation, in Fig. 5, the cured state of the resin paint 23 is shown filled in gray.

[0043] The resin paint 23 is a paint made of, for example, a polymer material, a silicone rubber, a butadiene rubber, a urethane rubber, an epoxy resin, a vinyl ester resin, a polyurea resin, etc. When radiation resistance is taken into consideration, an epoxy resin or the like can be selected as the resin paint 23.

[0044] The third modified example is effective when it is not possible to specifically identify the location of the rupture site X. Even when the third modified example is adopted, the work simply involves dripping the resin paint 23 onto the outer periphery of the outermost shell portion S1 and letting it drip, so the work can be carried out by a remotely controlled robot.

[0045] According to the water-stopping method for the multi-structured part S of the above-mentioned embodiment (including the modified example), a primary water-stopping process is carried out by supplying a water-absorbent primary water-stopping material 1 to the rupture site X from the inside of the outermost shell part S1 of the multi-structured part S, thereby roughly sealing the gap at the rupture site X, and by sealing the rupture site X with a secondary water-stopping material 2, water leakage from the rupture site X can be effectively prevented.

[0046] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention.

[0047] This disclosure can contribute, for example, to Goal 7 of the United Nations-led Sustainable Development Goals (SDGs), "Ensure access to affordable, reliable, sustainable and modern energy for all" and Goal 13, "Take urgent action to combat climate change and its impacts." [Explanation of symbols]

[0048] 1 Primary waterproofing material 2 Secondary waterproofing material 3 Supply piping 4 Source 5. Pump 21 Resin sheet 22,23 Resin paint S multiplex structure S1 Outermost shell S2 Inner piping X Breakage point

Claims

1. a primary water-stopping step of supplying a water-absorbent primary water-stopping substance into a space formed inside the outermost shell of the multi-layer structure having the ruptured portion; a secondary water-stopping step of sealing the ruptured portion of the outermost shell portion with a secondary water-stopping material; A waterproofing method for a multi-layer structure, comprising:

2. The waterproofing method for a multi-layer structure according to claim 1 , wherein the primary waterproofing material is a water-absorbent polymer.

3. 2. The waterproofing method for a multi-layer structure according to claim 1, wherein the secondary waterproofing material is a hardening agent, and the secondary waterproofing step is a step of supplying the hardening agent into the space to which the primary waterproofing material has been supplied.

4. 2. The waterproofing method for a multi-layer structure part according to claim 1, wherein the secondary waterproofing material is a resin sheet, and the secondary waterproofing step is a step of covering the outside of the outermost shell part with the resin sheet.

5. 2. The waterproofing method for a multi-layer structure according to claim 1, wherein the secondary waterproofing material is a resin paint, and the secondary waterproofing step is a step of applying the resin paint to the outside of the outermost shell part.

6. The waterproofing method for a multi-layer structure according to claim 1 , wherein the secondary waterproofing material is a radiation-resistant waterproofing material.

7. The waterproofing method for a multi-layer structure according to claim 1 , wherein the primary waterproofing step and the secondary waterproofing step are performed by a remotely controlled robot.

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