JPH08217191A - Explosion release structure for tank - Google Patents

Abstract

PURPOSE: To provide an explosion release structure for a tank, without requiring a high level of skill in welding work, relatively simple in structure and, moreover, capable of releasing explosion caused by the slight increase of an inner pressure. CONSTITUTION: A top angle 3 is fixed to the upper end of a cylindrical side plate 1 of a tank set on the foundation in such a manner that a flange part 3a of the top angle 3 is directed outward. Then, a roof plate 2 is set so that its outer peripheral edge is placed on the flange part 3a, and the outer peripheral edge 2a is covered with a sealing material 5. A cylindrical sealing plate 4 is welded and fixed to the underside of the roof plate 2 and to the inner side of the top angle 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosive structure for a fixed roof of a tank for storing a flammable liquid such as crude oil or orimulsion.

[0002]

2. Description of the Related Art A tank for storing flammable liquids such as crude oil and orimulsion has a conical or spherical roof plate (2) on a cylindrical side plate (1) installed on a foundation as shown in FIG. ) Is placed, and its perimeter is fixed by welding. With the flammable liquid (8) in this tank, the internal pressure suddenly rises due to a fire or the like, and the joint between the side plate and the bottom plate breaks, the flammable liquid (8) flows out, This burns and causes a great disaster. Therefore, conventionally, as shown in FIG. 4, the top angle (3) is welded onto the side plate (1), and the roof plate (2) is placed on the flange portion (3a) of the top angle (3). The end of (2) was fillet welded to the flange (3a), but the leg length (L) of the fillet weld should be shorter than the thickness of the roof plate (2) and the side plate (1). When the internal pressure of the tank rises, the top angle (3) buckles and the fillet weld (9) is cut before the joint between the side plate and the bottom plate is broken, and the internal pressure is released from the gap. Was released to prevent the escape of flammable liquids.

Further, as described in Japanese Utility Model Publication No. 5-16157, bolt holes are provided in the flange portion of the top angle, and the peripheral edge portion of the roof plate is located at a position corresponding to the bolt hole of the flange portion. A notched bolt hole is provided at the outer peripheral end of the gasket, a gasket is sandwiched between the flange and the peripheral edge of the roof plate, a bolt is inserted into the bolt hole, and the nut is tightened. Is also known. Further, as described in Japanese Utility Model Publication No. 5-16158, a top angle is welded on a side plate so that a flange portion faces outward, and an outer peripheral edge of a roof plate is attached to a tip portion of the flange portion. It is also known that they are overlapped with each other and are subjected to extra welding over the entire circumference across the overlapping end faces of the flange portion and the roof plate. Furthermore, actual fairness 5-16
As described in Japanese Patent Publication No. 159, an annular auxiliary discharge plate is butted to the outer edge of the top angle flange portion, and the welding is smaller than the thickness of both of these plates, and the seal welding is performed by opening the lower side from the upper side. It is also known that the outer peripheral edge of the roof plate is fixed to the auxiliary plate for detonation by seal welding.

[0004]

By the way, when the tank becomes large, it becomes necessary to increase the cross-sectional area of the top angle to increase the strength in order to support the load of the roof portion. However, in the detonation structure of Fig. 4, if the strength of the top angle is increased, even if the internal pressure of the tank rises, the joint between the side plate and the bottom plate is destroyed before the detonation of the top angle due to buckling deformation, and the radiation is released. There is a risk that the explosion structure may not be achieved.

Further, since the explosive structure described in Japanese Utility Model Publication No. 5-16157 does not weld, a high level of skill is not required for the welding work, but a bolt formed in a cutout shape on the roof plate. Since it is necessary to provide holes and the like, it is troublesome to manufacture them, and the roof plate and the bolts or nuts may be rusted during use, and the roof plate may not come off under a predetermined pressure. Further, in the explosive structure described in Japanese Utility Model Publication No. 5-16158, unlike the conventional explosive structure described above, the welded portion is easily broken, but the peeling property of the roof plate and the roof plate are retained during explosion during welding. It is necessary to carry out welding in consideration of the strength of the tank and the airtightness of the tank, and a high degree of skill is required for welding work. Further, in the explosive structure described in Japanese Utility Model Publication No. 5-16159, an annular auxiliary plate for detonation is butted against the outer edge of the flange portion for seal welding, and this seal welding is highly skilled. Was needed. An object of the present invention is to provide a detonation structure for a tank which does not require a high level of skill in welding work, is relatively simple in structure, and detonates with a slight increase in internal pressure.

[0006]

In order to achieve the above object, in the detonation structure of the present invention, a top angle is fixed to an upper portion of a cylindrical side plate installed on a foundation so that a flange portion faces outward. Then, install the roof plate so that the outer peripheral edge rides on the flange portion, and weld the cylindrical seal plate to the lower side of the roof plate and the inside of the top angle to fix it to the outer peripheral edge of the roof plate. Is covered with a sealing material.

In the above explosive structure, welding is performed so that the strength of the weld between the cylindrical seal plate and the inside of the top angle is smaller than the strength of the weld between the lower side of the roof plate and the seal plate. Is. In addition, it is to make the seal plate thinner than the thickness of the roof plate and the side plate.
Although the adhesive strength of pitch, rubber, etc. is not strong, a material that seals against rain, wind, and dust is used.

[0008]

In the explosive structure of the present invention, when the pressure in the tank rises due to an explosion or the like, the roof plate (2) is deformed upward and the seal plate (4) is pulled upward as shown in FIG. , The welded part (7) inside the top angle (3) is broken, the sealing material (5) is blown off by the internal pressure, and the internal pressure is released at once from the gap between the seal plate (4) and the top angle (3), Even if the angle (3) does not buckle and deform, it is possible to prevent the flammable liquid (8) from flowing out due to the breakage of the joint between the side plate (1) and the bottom plate. Also, roofing board (2)
Since the seal plate (4) which is firmly welded and fixed to the top angle (3) is inserted into the top angle (3), even if the strength of the welded part (7) inside the top angle (3) is small. The roof plate (2) does not move even when a force such as wind acts on the roof plate (2) from the outside.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the tank detonation structure of the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional view of an essential part showing an example of the present invention, FIG. 2 is an explanatory view showing a deformed state of the essential part of the detonation structure at the time of explosion of the tank shown in FIG. 1, and FIG. It is a schematic longitudinal cross-sectional view showing an example of a ground-installed tank to which is applied. 1 and 3, the tank detonation structure of the present invention has a cylindrical side plate (1) installed on a foundation, a flange portion (3a) facing outward, and an inner diameter of the side plate (1). It is fixed by welding a cylindrical top angle (3) having the same inner diameter as.

On the top angle (3), a roof plate (2) having a conical outer peripheral edge and smaller than the outer diameter of the flange portion (3a) of the top angle (3) is placed. The edge (2a) is covered with the sealing material (5). Between the roof plate (2) and the inside of the top angle (3), the plate thickness is thinner than the side plates (1) and the roof plate (2), and the outer diameter is equal to the inner diameter of the top angle (3). A cylindrical sealing plate (4) is fixed by welding. That is, the upper end of the cylindrical seal plate (4) is fixed to the lower side of the roof plate (2) by welding (6), and the lower end thereof is fixed to the inner side of the top angle (3) by welding (7). This seal plate (4)
The strength of the welded portion (7) that welds the lower end of the inside of the top angle (3) to the welded portion (6) below the roof plate (2), the strength of the side plate (1) and the roof plate. Welded to be smaller than the strength of (2).

Next, referring to FIG. 2, the state where the internal pressure increases and the welded portion (7) inside the top angle (2) is broken will be described. The internal pressure increases and the roof plate (2) moves upward. When it swells to the top, the seal plate (4) is pulled upward, the weld portion (7) where the seal plate (4) is welded to the inside of the top angle (3) is broken, and the seal plate (4) and the top are Since the internal pressure is released from the gap of the angle (3), the sealing material (5) is blown off and released to the outside of the tank,
The side plate (1) and the roof plate (2) are not destroyed,
Further, the flammable liquid does not flow out due to the breakage of the side plate (1).

The present invention is not limited to the above-described ones, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0013]

The present invention has the above-mentioned structure,
It has the following excellent effects. (1) Since the strength of the welded portion (7) where the seal plate (4) is welded to the inside of the top angle (3) may be extremely weakened, even if a slight increase in pressure causes a detonation. (2) Further, since the strength of the welded portion (7) where the seal plate (4) is welded to the inside of the top angle (3) may be weakened, a high degree of skill is not required for welding. (3) Since the seal plate (4), which is firmly welded and fixed to the roof plate (2), is inserted into the top angle (3), the welded part (7) inside the top angle (3) is used. Even if the strength of) is small, the roof plate (2) does not move even when a large force such as wind acts on the roof plate (2) from the outside.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing a deformed state of a main part of the detonation structure at the time of explosion of the tank shown in FIG.

FIG. 3 is a schematic vertical sectional view showing an example of a ground-installed tank to which the present invention is applied.

FIG. 4 is a vertical cross-sectional view showing a main part of a conventional tank explosion structure.

FIG. 5 is a schematic vertical cross-sectional view showing an example of a ground-based tank having a conventional detonation structure.

[Explanation of symbols]

 1 Side plate 2 Roof plate 3 Top angle 3a Flange part 4 Seal plate 5 Seal material 6 Welding part under roof plate 7 Welding part inside top angle 8 Flammable liquid

Claims (2)

[Claims] 1. A top angle (3) is fixed to an upper portion of a cylindrical side plate (1) installed on a foundation so that a flange portion (3a) faces outward, and an outer peripheral edge is provided on the flange portion. The roof plate (2) is installed so that the rider rides, and the cylindrical seal plate (4) is welded to the lower side of the roof plate (2) and the inside of the top angle (3), and the outer peripheral edge (2a ) Is covered with a sealing material (5). 2. The strength of the weld (7) between the cylindrical seal plate (4) and the inside of the top angle (3) is such that the roof plate (2)
The detonation structure for a tank according to claim 1, wherein welding is performed so that the strength is lower than the strength of the welded portion (6) between the lower side and the seal plate (4).