JPS60200719A - Wire penetrating portion - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention mainly relates to an electric wire penetration part that penetrates a partition wall that requires an airtight seal, such as a containment vessel of a nuclear power plant.

[Prior art]

In preparation for the depletion of oil resources in the future, a switch to nuclear power generation is being made gradually. The core of nuclear power generation, the reactor, is housed in a containment vessel, also known as a pressure vessel. There are several wire penetrations for various wires used for this purpose. Such a wire penetration part is strictly required to have an airtight structure so that radioactive substances do not leak through the wire penetration part. Now, as this type of wire penetration part, the one shown in FIG. 1 has been known in the past. FIG. 1 shows one end of the outer cylinder 1 that is airtightly attached to the penetrating wall of the containment vessel. An end plate 3 having a large number of through holes 2
In this case, when welding the inorganic insulated metal sheathed wire 4 (hereinafter referred to as MIC) that is penetrated through each of the through holes 2 in an airtight manner, the entire welded part 2a on the outer periphery of the MIC 4 is uniformly welded. There must be. Here, MIC is a conductor insulated with an inorganic material such as magnesium oxide, and an S
It refers to a product coated with a metal 7-base such as uS. In general, the shorter the length of the wire penetration part to be welded or rolled, the fewer defects such as pinholes will occur, and as a result, the reliability of airtightness will be improved. Therefore, it is also necessary that the wire penetration portion be as small as possible. Therefore, the surface of the end plate 3 having the through holes 2 is narrow, and the intervals between the through holes 20 are also narrow. Therefore, M.I.
As we welded C4 one by one, the one attached next to it gradually got in the way, and welded one C4 over the entire circumference of MIC4.
・The welding work becomes unstable and difficult, as it is impossible to weld while keeping the wires at the same angle.In this way, in the conventional wire penetration part, It is extremely difficult to create an airtight seal between the provided through-holes 2 and the MIC 4 by welding, sealing, etc. In particular, the greater the number of through-holes 2, the greater the problem. .Also, apart from this, there is also a case where the part corresponding to end plate 3 in Figure 1 is hardened with epoxy resin, etc., but if there are many MIC4 or solid conductors that pass through as above, all It is very difficult to fill and solidify the resin to maintain airtightness between the MIC 4 and the solid conductor, and there is also the problem that if there is an airtight leak in some places, the whole thing has to be redone.

[Purpose of the invention]

In view of the above problems, an object of the present invention is to
To provide an electric wire penetration part that is easy to perform sealing work such as welding, and therefore has high airtight reliability when a MIC is passed through the through holes of both end plates having through holes and the gap is airtightly pooled. It is in.

[Structure of the invention]

In order to achieve the above object, in the electric wire penetration part of the present invention, end plates having opposing through holes are attached to both ends of the outer cylinder in an airtight manner, and the MIC is inserted through the opposing through holes of the respective end plates. In a wire penetration part that is airtightly installed and in which the outer tube is airtightly cut into the through wall, there are a few end plates attached to both ends of the outer tube (in both cases, one end plate has one end plate on one side). , a flexible and stretchable metal tube protrudes outward and is installed in an airtight manner in the through hole, and a space between the metal tube and the metal sheath of the MIC passing through the metal tube is airtight. It is sealed.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows an embodiment of the present invention. As shown in this figure, in the end plates 3 and 5 having a plurality of through holes 2, a spiral metal pipe or a metal sparse pipe or the like is inserted into the through holes 2 in advance. A flexible metal tube 6 having flexibility and stretchability is passed through and airtightly welded inside the end plate to form a welded portion 6a. In addition, in FIG. 2, the inner surfaces of the end plates 3 and 5 and the end surface of the flexible metal tube 6 are welded almost flush, but the end surface of the flexible metal tube is expanded into a brim shape, and the end plate It is preferable to weld or braze the insides of the welds 3 and 5 as shown in FIG. 3, since this improves the strength of the welded portion 6a. Now, after the flexible metal tubes 6 that are welded or brazed on the inside of the end plates 3 and 5 and protrude toward the outside are attached airtightly, the end plates 3 and 5 with the flexible metal tubes are attached. The outer cylinder 1 is arranged so that each flexible metal tube 6 faces outward.
Weld the welded parts 3a and 5a to the parts and attach them airtightly. Of course, it is not limited to welding as long as it can maintain airtightness. It should be noted that in each of the through holes 2 of the end plates 3 and 5, the center axes of the opposing through holes do not necessarily have to coincide, but it is better to do so when passing the electric wire through them. It's convenient. In addition, in Fig. 2, pressurized nitrogen gas is sealed in the inner space formed by the outer cylinder] and the end plates 3 and 5, and internal pressure fluctuations are constantly monitored to detect the presence or absence of gas leaks. A valve 7 and a pressure gauge 8 are attached to the pressure gauge 8.
It has a pressure detection hole 9 that communicates with the main body part I.
The outer cylinder is formed by welding the welded part 1a to A in an airtight manner, but in order to reduce the number of welded parts and increase the reliability of airtightness, the ring 1B and the main body part IA are fabricated in advance as a body and then attached to the outer cylinder. Cylinder 1
You can also use it as Now, after the end plates 3 and 5 are airtightly attached to the outer cylinder 1, the MIC 4 is passed through the opening of one of the flexible metal tubes 6, and its tip is brought out to the opening of the other flexible metal tube 6. Of course, there is no problem in inserting it from either direction. After the MIC 4 is inserted in this manner, the metal source of the MIC 4 and the flexible metal tube 60 are welded airtightly. Therefore, the inner diameter of the opening of the flexible metal tube 6 may be adjusted to the front. Here, if a through hole 15 is provided in the metal sheath as shown in FIG. 4 at part 0 in FIG. 2 of the MIC 4 inserted into the flexible metal tube 6, the outer tube and the end plate 3. Whether the pressurized nitrogen gas sealed in the space surrounded by 5 is not leaking through the MICJ or conversely, whether the radiation etc. inside the containment vessel is leaking through this MIC4 is Pressure gauge 8 allows constant pressure. In order to prevent leakage from the end of the MIC 4, as shown in FIG. Connect with , cover with metal case 20,
The metal case 20, the metal sheath of the MIC 4, and the insulator 17 are hermetically sealed by welding or brazing.

After the MIC 4 is installed as described above, the outer cylinder 1 is finally attached airtightly, for example, by welding, to the through wall 11 having the through part of the containment vessel. The welded portion 11a in FIG. 2 is the welded portion.

FIG. 6 shows an application example, in which multiple MIs are connected to a flexible metal tube 6.
When inserting C4, it is difficult to airtightly seal the metal sheath of the MIC4 and the opening of the flexible metal tube 6 as they are, so insert the spacer 21 and insert the spacer 21a, 21.
1) Solving the part airtight makes it easier to work and maintain airtightness. In addition, in FIG. 2, the flexible metal tube 6 is attached to both the end plates 3 and 50, but in some cases, one side may be combined with the conventional method as shown in FIG. 1 or 7. Good too. In Fig. 7, the metal case 22 is airtightly welded to the end plate 3 or 5 at either the 22a part or 221] part, and the metal sheath of the MIC 4 is airtightly welded to the welded part 4a at the tip opening of the metal case 22. It is welded to.

In this case, when using the conventional method only on one side,
There are cases where there is not enough space on one side and the length l from the end plate to the tip of the MIC4 cannot be secured.

As described above, in the present invention, as a method for airtightly sealing between the MIC that passes through the wire penetration part and the through hole that the MIC passes through, a structure that is easy to weld or braze, that is, an end The structure is such that the MIC and the flexible metal tube are hermetically welded or brazed at the tip of the flexible metal tube that is airtightly fitted into each through hole of the plate. Therefore, even if there are multiple through holes provided in the end plate and the flexible metal pipes are lined up in a row, it is necessary to bend the adjacent flexible metal pipes slightly so that they do not get in the way of welding or brazing work. It is possible to release the material to a location where it is easy to work on the material to be welded or brazed. Because the welding or brazing is performed at the tip of the flexible metal tube and the metal tube is flexible, welding or brazing between the flexible metal tube and the MIC is difficult. , it can be done in a constant position at all times, which makes it easier to obtain high quality welding and raw materials. In addition, if this flexible metal tube is attached to the end plate by welding or welding on the inside of the end plate, that is, on the side opposite to the protruding side of the flexible metal tube, the adjacent flexible metal tube can be attached. This is preferable because it does not interfere with work. Furthermore, when there are multiple flexible metal tubes standing in a row as shown in Figure 8, it is possible to shorten the length of the tubes that are located on the outside so that the neighboring tubes will be less likely to get in the way. Workability such as welding at the tip of a flexible metal tube is further improved. moreover,
In the present invention, as a method of airtight sealing, a sealing method by filling with resin such as epoxy resin is not used at all, but a method of individually welding or brazing is adopted. Therefore, each connection made by welding or brazing can be tested for airtightness to ensure that there are no leaks as the process progresses, and if a leak is found, it can be repaired at each step. At the same time, it has better human and heat resistance than the resin-filled type. In addition, from the viewpoint of heat resistance, even if the wire penetration part according to the present invention is exposed to high temperatures, the flexible metal tube absorbs the thermal stress generated due to this high temperature with its elasticity. Specifically, the thermal stress does not directly act on the connection portion between the flexible metal tube and the MIC 4.

In this way, it also has excellent heat resistance.

〔Effect of the invention〕

As described above, according to the present invention, when attaching the MIC that passes through the wire penetration part to the penetration part main body by welding or bracing, this workability is good, and therefore the airtight reliability of the connection part is high. In addition, it is possible to obtain a wire penetration portion having excellent fire resistance and heat resistance.

[Brief explanation of the drawing]

FIG. 1 is a partial longitudinal cross-sectional view showing a conventional electric wire penetration part, FIG. 2 is a partial longitudinal cross-sectional view showing an embodiment of the electric wire penetration part of the present invention,
3 is a partial vertical sectional view showing some examples of the flexible metal tube in FIG. 2 as another embodiment of the method, FIG. 4 is a partial vertical sectional view showing section C in FIG. 6 and 7 are partial vertical sectional views showing other embodiments of the present invention, and FIG. 8 is a partial longitudinal sectional view showing another embodiment of the present invention. FIG. 2 is a schematic diagram of an example of arrangement of flexible metal tubes; +A, IB Outer cylinder 3.5 End plate 4 Inorganic insulating metal/
- Soot electric wire 6/flexible metal tube II Penetrating wall 17 Insulator 20 Metal case 21 Spacer Figure 1 Figure 2 Figure 3 Figure 4 1Δ Figure 5 6F≧1 Figure 7

Claims (2)

[Claims] (1) End plates having opposing through holes are airtightly attached to both ends of the outer cylinder, and an inorganic insulated metal sheathed electric wire is hermetically attached through the opposing through holes of each end plate, and In a wire penetration part in which an outer cylinder is airtightly inserted into several through walls, at least one end plate of the end plates attached to both ends of the outer cylinder has a flexible plate in the through hole. A stretchable metal tube protrudes outward and is installed in an airtight manner, and the metal tube and the metal sheath of the inorganic insulated metal sheathed electric wire passing through the metal tube are airtightly sealed. A wire penetration part characterized by (2) In the case of multiple through holes, the length of the flexible metal tube installed in the through hole is shorter as the tube is installed in the outer through hole. An electric wire penetration portion according to claim 1, characterized in that: