JPH0812267B2 - Sodium combustion suppression bed - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floor structure that suppresses combustion by shutting down falling hot sodium from ambient air. More specifically, the thermal expansion difference due to the temperature difference of the thin metal plate is used to automatically perform the opening / closing operation, and the falling sodium is stored in the saucer,
After collecting in the saucer, confine sodium to extinguish the suffocation.
The present invention relates to a sodium combustion suppressing bed for preventing smoke generation. INDUSTRIAL APPLICATION This invention is useful as a floor structure of the fast reactor which uses sodium as a coolant.

[0002]

2. Description of the Related Art In a secondary cooling system of a fast reactor in which non-radioactive sodium circulates, system equipment and piping are installed in the atmosphere, and if sodium leaks out of the system, it suppresses combustion and extinguishes the fire. It is designed with the idea of processing later. Therefore, when sodium leaks out, the floor surface that may flow down and stay is designed to suppress combustion.

As an example, a device has been developed for extinguishing a suffocation while opening a tiltable shutter by hydraulic pressure of sodium accumulated on the floor and allowing it to flow down below the floor to block fumes (Japanese Patent Publication No. 59-52794). (See Japanese Patent Publication).

[0004]

However, in the above-mentioned conventional apparatus, a large number of plate bodies bent so as to form a wide-angle two-sided structure are alternately arranged in high and low, and the vertical openings between them are covered. Since the shutter is provided at the upper part, the space between the plate bodies arranged higher is widened, and it is considered difficult to walk on the upper surface of the device. In addition, the structure is complicated and it is difficult to manufacture.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, to provide a sodium combustion suppressing floor having a structure that is easy to manufacture with a simpler structure, is reliable in operation, and is easy to walk on the floor surface. Is to provide.

[0006]

The sodium combustion suppressing bed of the present invention has a structure in which a large number of unit structures that perform a sodium combustion suppressing function are arranged in parallel in a pan having a side wall. The unit structure is composed of upper and lower two-tiered support rods extending in the lateral direction, and a metal upper thin plate fixed to the upper support rod and the lower support rod and projecting diagonally downward from both support rods on both sides, and connecting the lower end edges to each other. It consists of a lower thin plate. These many unit structures are normally arranged at intervals such that the thin plates of the adjacent unit structures are substantially in contact with each other. Here, it is preferable that the upper support rod is installed between the side walls of the saucer, and the lower support rod is fixed on a columnar or rib-like support member that is erected from the bottom plate of the saucer. Such a saucer is arranged at a required place to form a floor surface.

[0007]

[Operation] When high temperature sodium drops, the upper thin plate has a higher temperature and a larger thermal expansion, so that it expands and deforms so that the unit structure is constricted. To house. When sodium accumulates in the saucer and burns there, the temperature of the lower thin plate becomes higher and the expansion due to thermal expansion is greater, and the unit structure deforms to expand and closes the adjacent thin plates, blocking smoke and suffocating. Extinguish the fire. Thus, the opening / closing operation between the adjacent unit structures is automatically performed by utilizing the temperature difference.

[0008]

1 is a perspective view showing one unit of a sodium combustion suppression bed. The sodium combustion suppressing floor unit has a unit structure 20 that performs a combustion suppressing function in the tray 10.
Are arranged in parallel. The arrangement interval between them is set to a width (about 3 cm or less) that does not hinder walking on it. The saucer 10 is composed of a steel bottom plate 12 and side walls 14 provided upright around the bottom plate 12. In practice, this unit is used by laying it in a predetermined place in the room.

Details of the unit structure 20 are shown in FIG. Each unit structure 20 includes an upper support rod 22 and a lower support rod 24 that extend laterally in two steps, and a central portion of both unit support rods 22, 2.
4 is made up of a metal upper thin plate 26 and a lower thin plate 28 fixed to each other by welding or the like.
It has a structure in which lower end edges are welded and connected to each other by projecting obliquely downwards from both sides of Nos. Both thin plates 26, 28
Is a device in which thin plate pieces having a constant width are arranged side by side so as to be continuous in the axial direction of the support rods 22 and 24 with almost no gap.
The shapes of the upper thin plate 26 and the lower thin plate 28 (overhang length and sagging angle) are set so that the thin plates of the adjacent unit structures are almost in contact with each other during normal times (see FIG. 1). The thin metal plate piece is preferably made of a material, such as stainless steel, that can withstand high temperature sodium at about 500 ° C., can be welded to a support rod, and has a large coefficient of thermal expansion.

Here, the upper support rod 22 has its both ends at the tray 1
Fixed to the opposite side walls 14 of 0, the lower support rods 24 are columnar or rib-shaped support members that stand upright from the bottom plate 12 of the tray 10 so as to be thermally insulated from the upper support rods 22 as much as possible. It is preferably fixed on top of 30.

Next, the operation of the sodium combustion suppression bed will be described with reference to FIG. As shown in FIG. 3A, normally, between the adjacent unit structures 20, the thin plates are slightly in contact with each other and are closed. Here, when the high temperature sodium drops from above, the upper thin plate 26 is heated and the upper thin plate 26 expands and expands, whereas the lower thin plate 28 does not expand because it remains at a low temperature, and the difference in the amount of thermal expansion between the two is high. As a result, the unit structure 20 is narrowed as shown in FIG. 3B. As a result, the space between the adjacent thin plates is expanded and the unit structure 20 is expanded.
An opening is formed between them, through which sodium easily falls into the saucer 10. When the sodium accumulates and burns, the lower thin plate 28 is heated and thermally expanded, and the degree of expansion thereof is much larger than that of the upper thin plate 26, so that it spreads as shown in FIG. 3C. As a result, the thin plates are pressed against each other so that the adjacent unit structures 20 are pressed against each other and the openings are closed, so that the sodium in the pan 10 is extinguished by suffocation and the rise of smoke is prevented. Even if the thermal expansion amounts of the upper thin plate 26 and the lower thin plate 28 are almost the same, since the adjacent thin plates are almost in contact with each other, the opening remains closed, and the functions of the above-described suffocation extinguishing and smoke prevention functions. Is maintained.

The preferred embodiment of the present invention has been described above in detail, but the invention is not limited thereto. In the above embodiment, the lower support rod 24 and the support member 30 are separately manufactured and joined by welding or the like, but they may be integrally molded in some cases. If the conditions allow, a bimetal or a shape memory alloy can be used as the metal thin plate for more sensitive operation.

[0013]

As described above, the present invention is configured to automatically open and close by utilizing the difference in the amount of thermal expansion due to the temperature difference of the thin metal plate. High-temperature sodium that comes in can be easily stored in the saucer, and after accumulating in the saucer, sodium can be trapped to reliably prevent suffocation and extinguish smoke and prevent smoke emission, and the operation is highly reliable. Since the unit structures can be arranged close to each other, the floor surface is close to a flat surface, which facilitates walking, and the workability on it is good. Further, since the structure is relatively simple, there is an advantage that it is easy to manufacture.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a sodium combustion suppression bed according to the present invention.

FIG. 2 is a perspective view showing details of the unit structure.

FIG. 3 is an operation explanatory view of the sodium combustion suppression bed according to the present invention.

[Explanation of symbols]

 10 saucer 12 bottom plate 14 side wall 20 unit structure 22 upper support rod 24 lower support rod 26 upper thin plate 28 lower thin plate 30 support member

Claims (2)

[Claims] 1. An upper and lower two-tiered support rod extending in a lateral direction, and an upper metal plate fixed to the upper and lower support rods and projecting obliquely downward from both support rods on both sides, and connecting lower end edges to each other. A sodium-combustion suppressing bed, characterized in that a large number of unit structure bodies each composed of a lower thin plate are arranged in parallel in a saucer provided with a side wall and at intervals such that the thin plates of the unit structure bodies which are normally adjacent to each other are substantially in contact with each other. 2. The sodium combustion suppressing bed according to claim 1, wherein the upper support rod is installed between the side walls of the saucer, and the lower support rod is fixed on a columnar or rib-like support member which is erected from the bottom plate of the saucer.