JPH0215118Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a double-shell cryogenic tank having a spheroid-shaped inner tank.

[Prior Art] Conventionally, liquids such as LPG and LNG are stored in spherical or cylindrical double-shell low-temperature tanks.

As an example of a double-shell low-temperature tank, an above-ground double-shell low-temperature tank is shown in Figure 4.
An outer tank bottom plate 16 is installed on the foundation slab 15, and an outer tank side plate 17 is assembled on the outer tank bottom plate 16, and an outer tank roof 18 is attached to the upper end of the outer tank side plate 17 to form an outer tank. On the outer tank bottom plate 16,
In addition to installing the bottom cold insulation block 19 in a ring shape, a bottom cold insulation material 20 is installed inside the bottom cold insulation block 19, and an inner tank bottom plate 21 is installed on the bottom cold insulation block 19 and the bottom cold insulation material 20. ,
An inner tank side plate 22 is assembled on the inner tank bottom plate 21, an inner tank roof 23 is attached to the upper end of the inner tank side plate 22 to form an inner tank, and a cold insulating material such as granular perlite is placed between the inner tank and the outer tank. 24, and in the case of a floating floor type, the foundation slab 15 is filled as shown in the figure.
However, the structure is such that it is installed on a pile 25 driven into the ground.

When the low-temperature liquid 26 is stored in the inner tank of an above-ground double-shell cryogenic tank having the above-mentioned configuration, the inner tank expands due to the gas pressure, and the inner tank side plate 22 is lifted up. Inner tank bottom plate 21 integrated with the lower end of
The surrounding area also rises. Furthermore, if an earthquake occurs while the low-temperature liquid 26 is stored in the inner tank, the movement of the low-temperature liquid 26 will cause an overturning moment to act on the tank, and a large vertical load will be generated at the lower part of the inner tank side plate 22, causing the inner tank to collapse. When a downward load is applied to a certain part of the side plate 22, an upward load is applied to the inner tank side plate 22 at a part on the opposite side. As a result, a portion of the inner tank side plate 22 is lifted and the bottom plate 21 also floats. When the next overturning moment occurs in the opposite direction in this state, the inner tank side plate 22 on the side that has already been lifted will receive a downward load, causing the inner tank side plate 22 and the inner tank bottom plate 21 to Significant strain fluctuations will occur at the corners, and there is a risk that the tank will be damaged.

In order to prevent such a situation, as shown in FIG. 4, the inner tank side plate 22 is fixed on the foundation slab 15 with an anchor strap 27, so that the inner tank side plate 22 will not be lifted up by gas pressure or falling force due to an earthquake. Traditionally, it has been done to ensure that there are no

[Problem to be solved by the invention] In the tank of the conventional shape described above, the inner tank side plate 2
There is a problem in that considerable distortion occurs at the discontinuous corner portions of the bottom plate 2 and the inner tank bottom plate 21 due to liquid pressure, temperature changes, seismic forces, etc.

Recently, a tank with a simple shape and a safe and inexpensive tank with no stress concentration points when subjected to forces such as hydraulic pressure, temperature load, seismic force, etc. has been developed to smoothly connect multiple arcuate cross-section ring bodies with different radii of curvature. A structure formed in a spheroid shape (water droplet shape or quasi-water droplet shape) has been proposed.

The present invention attempts to embody a double-shell cryogenic tank having such a spheroid-shaped inner tank.

[Means for Solving the Problems] The present invention was developed in view of the above-mentioned circumstances, and provides a double-shell cryogenic tank with a spheroid-shaped inner tank, in which the center part of the upper part of the inner tank is missing and the inner tank is removed. It is characterized by being connected to the outer tank by a support device at positions equally divided around the circumference of the tank.

[Function] The inner tank has a spheroid shape, and the stored low-temperature liquid generates an equal stress against the liquid pressure acting on it, and since the center of the upper part of the inner tank is missing, there is a gap between the inside of the inner tank and the inner and outer tanks. are in communication with each other, and gas pressure does not act on the inner tank, so there is no need to consider gas pressure when manufacturing the inner tank. Furthermore, since the inner tank and the outer tank are connected by a support, sufficient support is provided against horizontal forces caused by earthquakes, etc., and as a result, the inner tank can have a light structure.

[Examples] Examples of the present invention will be described below with reference to the drawings.

A bottom cold insulation material 2 is laid on the bottom surface of the outer tank body 1, and when a rubber balloon is filled with water and placed on a flat plate, a uniform film pressure is formed on the entire surface of the rubber balloon. An inner tank 3 having a spheroid shape, that is, a shape in which this occurs, is mounted. An outer tank roof 4 that covers the inner tank 3 is airtightly provided on the upper part of the outer tank main body 1, and the outer tank main body 1 and the outer tank roof 4 constitute an outer tank 5, and a cold insulating material 6 is provided on the inner surface of the outer tank 5. Paste.

The upper part of the inner tank 3 has a circular part missing in the center over a required range, and the missing opening 7
A corrugated ring 8 is fixed to the inner edge of. The wave returning ring 8 has a function of reinforcing the inner edge of the opening 7 and preventing the low-temperature liquid 9 from scattering against the moving liquid during an earthquake.

A bracket 10 is fixed to a portion of the inner tank 3 that is equally divided around the circumference of the upper end of the outer tank body 1, and the bracket 10 and the upper end of the outer tank main body 1 are connected by a support device 11. The support device 11 is fixed to the outer tank main body 1 with an anchor bolt 12, and is pivotally connected to the bracket 10 via a pin 13, so that even if the connection state between the outer tank main body 1 and the inner tank 3 changes, the inner tank 3 is designed so that no bending moment occurs.

In the tank configured as described above, the low temperature liquid 9 is stored in the inner tank 3 made of low temperature material, and the airtightness of the tank is ensured by the outer tank 5.

Since the upper part of the inner tank 3 is missing, the inside and outside of the inner tank 3 are in communication, and no gas pressure acts on the inner tank 3. There is no need for a pressure-resistant structure above this point. In addition, piping for extracting gas and injecting low-temperature liquid only needs to be passed through the outer tank 5, and there is no need to treat the part that penetrates the inner tank 3.

The shape of the inner edge of the opening 7 for returning waves is not limited to the example described above, and the inner edge 10 may be bent downward with a small radius of curvature as shown in FIG.

Furthermore, if the support device 11 is provided with a shock damper function, the natural frequency of the inner tank 3 can be changed, and resonance during an earthquake can be avoided.

[Effects of the invention] As described above, according to the invention, (i) the upper part of the inner tank is missing, which reduces the weight and makes it cheaper; (ii) the inner tank has a lighter structure because no gas pressure acts on it. (iii) There is no need to provide piping in the inner tank, so the piping structure and piping treatment are simple.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of an embodiment of the present invention, Fig. 2 is an enlarged view of part A in Fig. 1, Fig. 3 is an explanatory diagram showing another example of the shape of the inner edge of the inner tank opening, and Fig. 4 is an explanatory diagram It is an explanatory diagram of a conventional example. 3 is an inner tank, 5 is an outer tank, 7 is an opening, and 11 is a support device.

Claims (1)

[Scope of utility model registration request] A double-shell low-temperature tank equipped with a spheroid-shaped inner tank, characterized in that the upper center of the inner tank is missing, and the inner tank is connected to the outer tank at equally divided positions on the circumference by a support device. Heavy shell cryogenic tank.