JPH0326764Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to a fireproof and airtight structure for a cable penetration section where cables stored in a cable distribution shelf penetrate the wall or floor of a nuclear power plant. At nuclear power plants, which use a large amount of cables,
Cables are often housed in cable distribution shelves and wired in multiple strips. The cables stored in the cable distribution shelves are extended to each area of the nuclear power plant by passing through openings such as holes provided in the walls and floors of the nuclear power plant. On the other hand, if a fire breaks out inside a nuclear power plant, there is a risk that the cables will spread flames and smoke and spread the fire. It is necessary to seal the penetrating part with effective fire prevention measures. Furthermore, in the event of an accident at a nuclear power plant, it is necessary to prevent radioactivity from spreading from the reactor room to other areas. Care has been taken to keep the atmospheric pressure low. For this reason, in nuclear power plants, it is necessary to close the above-mentioned cable penetrations with a structure that is effective for fire prevention, and to maintain the pressure difference between each room, it is necessary to seal the cable penetrations with a structure that is effective for airtightness. becomes. Conventionally, as a countermeasure to this problem, structures with emphasis on fire protection and structures with emphasis on airtightness have been provided, but we have developed an economical cable penetration that is both fireproof and airtight. There was no structure. FIG. 1 is an example showing the structure of a conventional cable penetration part with emphasis on fire protection. In the structure shown in FIG. 1, an opening 2 such as a through hole is formed in a wall 1 of a building, and a cable distribution shelf 3 and cables 4 stored therein are passed through the opening 2. Between the outside of the wiring shelf 3 and the opening 2,
A plurality of plate-shaped fireproof partitions 5 are provided to close the opening 2, and a fireproof putty-like sealing material 6 is filled between the cable distribution shelves 3 and cables 4 and the fireproof partitions 5 through which they pass. The outer periphery of the protruding ends of the cable distribution shelves 3 and cables 4 from the fireproof partitioning material 5 was covered with the sealing material 6, and furthermore, the closed space of the opening 2 formed between the fireproof partitioning materials 5 was filled with rock wool 7. It is something. According to the structure shown in Fig. 1, due to the action of the fire-retardant putty-like sealing material 6 that exhibits a high degree of fire-retardant performance, in the event of a fire, it is possible to shut out a fire that lasts about two hours as specified in JISA1304. Because the multiple cables 4 are not sealed,
There is a problem in that sufficient airtightness cannot always be achieved. In addition, in this fireproof structure, in order to exhibit fireproof performance for a longer period of time, it is necessary to increase the distance between the fireproof partitions 5, but if this distance becomes long, the cables are stored in the cable distribution shelf 3. Since the heat radiation of the cable 4 is suppressed,
A problem arises in that the permissible current of the cable 4 is reduced. Furthermore, in this fireproof structure, it is not impossible to improve the airtightness by packing fireproof putty-like sealing material between the multiple cables 4, but in order to achieve the desired airtightness, Since this requires a great deal of labor, the economical efficiency is significantly reduced and it cannot be put to practical use. FIG. 2 is an example showing the structure of a conventional cable penetration part with emphasis on airtightness. What is shown in FIG. 2 is a closed space in which a caulking material 8 is filled between the cable distribution shelf 3 and the cables 4 and the fireproof partition 5 through which they pass, and the opening 2 is formed between the fireproof partitions 5. is filled with a fireproof foam sealing material 9, and a portion of this is also filled between the multiple cables 4. Note that the structure of this airtight structure other than those described above is almost the same as that shown in FIG. 1, so parts corresponding to those in FIG. 1 are given the same reference numerals as in FIG. . According to the structure shown in FIG. 2, the fireproof foam sealing material 9 is in a liquid state when injected and flows between the multiple cables 4, and then becomes a closed-cell foam, so that good airtightness is achieved. However, the fire-retardant foam sealing material 9 has inferior fire-retardant performance compared to the fire-retardant putty-like sealing material 6, and in order to obtain the preventive performance that blocks fires after heating for about 2 hours as specified in JISA1304, it is necessary to , it is necessary to increase the distance between the fireproof partitions 5, and in order to obtain long-term fire protection performance, the allowable current of the cable 4 must be As this decreases, the amount of fire-retardant foam sealing material required increases, resulting in an economical disadvantage. The purpose of this invention is to solve the above-mentioned problems and economically provide a structure that can ensure sufficient fire protection and airtightness of the cable penetration section. That is, this invention covers at least one of the open surfaces of the cable distribution shelf with a noncombustible plate at the cable penetration part where the cables stored in the cable distribution shelf penetrate the wall or floor of the nuclear power plant, and both ends of the cable distribution shelf are covered with a noncombustible plate. A cable housing is constructed by sealing the cable housing with a caulking material, and a liquid fireproof sealing material is sealed in the sealed space inside the cable housing, and the space between the outer periphery of the cable housing and the opening in the wall or floor is sealed. A plurality of fireproof partitions having a mutual distance shorter than the thickness of the wall or floor are provided in the length direction of the cable housing so as to close the opening, and the fireproof partitions formed between these fireproof partitions are A liquid fireproof sealant is filled in the closed space of the opening, and the length of the storage body is made longer than the distance between the fireproof partitions, and both ends of the cable storage body are connected to the outside of the fireproof partitions. The gist of this is a fireproof and airtight structure for the cable penetration portion that protrudes outward from the end face. Hereinafter, embodiments of this invention will be described with reference to the drawings. FIG. 3 shows a fireproof and airtight structure of a cable penetration part according to an embodiment of this invention. In the structure shown in FIG. 3, an opening 2 such as a through hole is formed in a wall 1 of a building, and a cable distribution shelf 3 and a cable 4 supported thereon are passed through the opening 2. Note that the cable distribution shelf 3 has corner bars 3 on both sides.
It is a ladder-like structure made of steel, with square rods 3b installed and fixed at required intervals between a. Incombustible plates 10a and 10b made of steel plates are supported on the upper and lower surfaces of both corner bars 3a of the cable distribution shelf 3 to cover the upper and lower open surfaces of the cable distribution shelf 3, and a cable storage body 11 in the form of a sealed duct is constructed. Ru. Both ends of this cable housing 11 are covered with caulking material 12 such as "Fiberflux #10" (product name) manufactured by Toshiba Monoflux Corporation or "Danseal P" (product name) manufactured by Furukawa Electric Co., Ltd. It will be sealed. In this way, in the closed space inside the cable housing 11 with both ends sealed, "SE1900RTV Foam" (product name) manufactured by Toray Silicone Co., Ltd. or "Danseal L" (product name) manufactured by Furukawa Electric Co., Ltd. A fireproof sealing material 13 such as the following is injected. In addition, this fireproof sealing material 1
3 is a two-component mixture that cures at room temperature, such as one that becomes a spongy solid with a specific gravity of about 0.3 after curing (SE1900RTV form), and one that becomes a rubber-like solid with a specific gravity of about 1.4 after curing (Danseal L). It is. Further, the sealing of both ends of the cable storage body 11 with the caulking material 12 can be facilitated by filling the caulking material 12 in advance before attaching the noncombustible plates 10a, 10b to the cable distribution shelf 3. moreover,
The fireproof sealing material 13 is injected into the cable distribution shelf 3.
Injection can be easily performed by drilling two or more injection holes in advance in the noncombustible plate 10a installed on the upper surface of the incombustible plate 10a, and injecting from one of these holes. Two fireproof partition members 5 made of a steel plate or a calcium silicate plate such as "Keicalite" (trade name) manufactured by Asahi Asbestos Co., Ltd. are installed between the cable storage body 11 and the opening 2 through which it passes. are installed in pairs. The distance A between these fireproof partition materials 5 is the cable storage body 1.
1 is shorter than the length B of the cable storage body 1.
Both ends of the fireproof partition material 5 project outward from both outer end surfaces of the fireproof partition material 5, respectively. In the gap between the fireproof partition material 5 and the cable storage body 11 and the gap between the fireproof partition material 5 and the peripheral wall of the opening 2, a caulking material 14a such as the "Fiberflux #10" or "Danseal P", 14b is packed, and "SE1900RTV form" or "Danseal L" is applied to the closed space of the opening formed between the fireproof partition materials 5.
A fireproof sealing material 15 such as the following is injected. This injection can be easily performed by making two or more holes in advance in the upper part of at least one of the fireproof partition members 5 and pouring into at least one of these holes. FIG. 4 shows another embodiment of this invention. In this embodiment, cables 4 are housed in cable storage bodies 11 arranged in a plurality of upper and lower stages. The same symbols as in FIG. 3 indicate mutually corresponding parts. Further, in the above-mentioned embodiment, the cable storage body 11 is passed through the wall 1, but this invention can also be applied to a structure where the cable storage body is passed through an opening provided in the floor of a building. Furthermore, in this invention, the cable distribution shelf 3
In the case of a cable penetrating portion which is arranged horizontally and penetrates the wall 1, it is possible to have a structure in which the noncombustible plate 10a on the upper surface of the cable distribution shelf 3 shown in FIGS. 3 and 4 is removed. In this case, the fireproof sealing material 15 filled between the fireproof partition plates 5 needs to be injected after the fireproof sealing material 13 injected into the cable housing 11 has hardened. The fireproof and airtight structure of the cable penetration part configured as described above is based on the cable housing length B of 300 mm or more, considering fire prevention, airtightness, and economical efficiency.
It is preferable that the distance A between the fireproof partition plates be 1000 mm and about 100 mm to 300 mm. The cable distribution rack referred to in this specification is what those skilled in the art would call a cable tray or cable rack, including the cable distribution shelf of the embodiment of the invention described above. Furthermore, in Table 1,
Data is shown comparing the fire protection performance, airtightness, cable allowable current reduction rate, and economic efficiency of the conventional method (examples shown in Figures 1 and 2) and the method of this invention (example shown in Figure 3). .

【table】

[Table] Expressed as an index.
As explained above, the fireproof and airtight structure of the cable penetration part according to this invention has the fireproof performance and airtightness of the part where the cables stored in the cable distribution shelf pass through the openings in the walls and floors of the nuclear power plant. It is possible to secure a sufficient amount of energy, and it is also economical. That is,
Generally, the presence of cable distribution shelves and cable conductors, which are good conductors of heat, increases the temperature of the cable sheathing on the anti-fire side, which has a large impact on fire protection performance. The length of the cable storage body is long, and both ends of the cable storage body protrude outward from both outer end surfaces of a fireproof partition installed in an opening formed in a wall or floor and are in direct contact with the air. Because it provides a cooling effect, it has a high degree of fire protection performance, such as the ability to block fires that require 3 hours of heating as stipulated by JISA1304. , there is almost no reduction in the allowable current of the cable. Furthermore, since the height (thickness) of cable distribution shelves is generally small,
The volume of the space inside the cable storage body is small;
In addition, the distance between the fireproof partitions is short, and therefore the volume of the space between the fireproof partitions is small. Therefore, with this invention, the amount of fireproof sealing material sealed in each space is small. In addition to being economical, the fireproof sealing material and the caulking material that seals both ends of the cable storage body provide the effect that fireproofness and airtightness are sufficiently ensured.

[Brief explanation of the drawing]

Figures 1 and 2 are side sectional views showing an example of a fireproof structure and an airtight structure of a conventional cable penetration section, respectively, and Figures 3 and 4 are cable penetrations according to one embodiment of this invention and other embodiments. FIG. DESCRIPTION OF SYMBOLS 1... Building wall, 2... Opening, 3... Cable distribution shelf, 4... Cable, 5... Fireproof partition plate, 10a, 10b... Noncombustible board, 11... Cable storage body, 12... ...Caulking material, 13... Fireproof sealing material, 14a, 14b... Caulking material,
15...Fireproof sealing material.

Claims (1)

[Scope of utility model registration request] At the cable penetration part where the cables stored in the cable distribution shelf penetrate the wall or floor of the nuclear power plant, at least one of the open surfaces of the cable distribution shelf is covered with a noncombustible board, and both ends of the cable distribution shelf are covered with caulking material. The cable housing is sealed to form a cable housing, a liquid fireproof sealing material is sealed in the sealed space inside the cable housing, and the opening is placed between the outer periphery of the cable housing and an opening in the wall or floor. A plurality of fireproof partitions are provided in the length direction of the cable storage body with a mutual distance shorter than the thickness of the wall or floor so as to close the closed space of the opening formed between these fireproof partitions. At the time of sealing, a liquid fireproof sealing material is sealed, the length of the cable housing is made longer than the distance between the fireproof partitions, and both ends of the cable housing are placed outward from both outer end surfaces of the fireproof partitions. A fireproof and airtight structure for the cable penetration part, which is characterized by a protruding part.