JPH0417320B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a concrete double-shell cryogenic storage tank for storing ultra-low temperature liquefied gas such as LNG.

<Prior Art> Conventionally, a storage tank for ultra-low temperature liquefied gas has a double structure in which the inner and outer tanks are made of steel.

Regarding this type of storage tank, a storage tank whose inner and outer tanks are made of concrete is known from Japanese Patent Publication No. 1983-4600.

<Problems to be Solved by the Present Invention> The conventional storage tank described above has the following problems.

<B> In the former type of storage tank, the piping equipment for receiving and discharging liquid is made of the same steel as the storage tank, so it has the advantage of being highly reliable against temperature contraction and stress during earthquakes, but on the other hand, the construction cost is very high. arrive.

<B> In the case of the latter storage tank, metal piping equipment is supported by penetrating the concrete inner and outer tanks.

Therefore, the inner and outer tanks and piping equipment cannot absorb temperature contraction and deformation during earthquakes, and there is an extremely high risk that the storage tank and piping equipment will be damaged, which poses a safety problem.

<Objective of the present invention> The present invention was made to solve the above problems, and its purpose is to create a concrete double-layer structure that is low cost and can ensure high safety against temperature shrinkage and earthquakes. The purpose of the present invention is to provide a shell cryogenic storage tank.

<Means for Solving the Problems> That is, the present invention includes an inner tank having a sealed structure made of concrete and placed in an outer tank having a sealed structure made of concrete, and a heat insulating material is provided between the entire circumferential surfaces of both tanks. In a concrete double-shell storage tank in which piping equipment for receiving and discharging liquid is suspended from the tank with a material interposed between them, openings are opened on the same perpendicular line of each dome of both tanks, and the opening on the outer tank side is used for the piping equipment. The lid material for the outer tank is passed through to maintain airtightness and closed, and the metal lid material for the inner tank is penetrated and fixed with piping equipment, and the lid material for the inner tank is attached to the inner tank. A double-shell concrete low-temperature storage tank, which is slidably placed on the top surface of the opening of the tank or the outer tank, and the space between the lid material for the inner tank and the opening is closed with a sealing material. be.

<Configuration of the Present Invention> The present invention will be described below with reference to the drawings.

<A> Overall configuration of storage tank FIG. 1 shows an example of a concrete double-shell low-temperature storage tank according to the present invention.

The concrete double-shell cryogenic storage tank consists of an inner tank 1 with a sealed structure and an outer tank 2 in which the inner tank 1 is placed and accommodated.

Both tanks 1 and 2 are made of concrete.

A heat insulating material 6 such as perlite is filled between the circumferential surfaces of both tanks 1 and 2.

Each part will be explained in detail below.

<B> Inner tank (Figures 1 and 2) The inner tank 1 is a dome-shaped sealed body whose bottom, side walls, and roof are integrally formed of concrete.
The entire inner wall is covered with membrane, which has excellent low-temperature brittleness.

FIG. 2 is a partial sectional view of the roof of the inner tank 1, in which an opening 12 is opened in the center of the roof of the inner tank 1.

The opening 12 is a space in which piping equipment A for receiving and discharging liquid and lifting stage equipment B for inspection shown in FIG. 1 are suspended into the inner tank 1.

In the present invention, in order to cope with the behavior caused by temperature contraction and earthquakes, the following hanging structure of each equipment A and B is adopted.

That is, the periphery of the opening 12 is raised upward to form the cylindrical flange 13, and
A horizontal support surface 14 is formed on the inner circumference of the flange 13, and a large diameter surface 15 and a small diameter surface 16 having different diameters are formed above and below the horizontal support surface 14, respectively.

<C> Inner lid (Figures 2 and 3) The inner lid 3 fixes the various equipment A and B described above, and is slidably placed on the upper surface of the flange 13 of the inner tank 1 to close the opening 12. With a lid material intended for
For example, a closing plate 3 made of a circular stainless steel plate, etc.
1 and a reinforcing cylinder 32 integrally connected to the lower surface of the closing plate 31.

The reinforcing tube 32 has an outer diameter slightly smaller than the small diameter surface 16 of the opening 12, and a plurality of vertical plates 33 are provided on the upper outer circumferential surface of the reinforcing tube 32 in a longitudinal direction.

The vertical plate 33 is connected to the occlusion plate 31 as shown in FIG.
Before contacting the flange 13, the vertical plate 33
A sliding surface 34 formed on the lowermost surface of the opening 12 is attached at a position where it can be placed on the horizontal support surface 14 .

In addition, the protruding width of the vertical plate 33 is set to a size that does not contact the large diameter surface 15 of the opening 12, and the vertical plate 33 is
The dimensions are set to allow sliding between the slide surface 34 of No. 3 and the horizontal support surface 14.

The piping equipment A is passed through the center of the closing plate 31, and the penetration point is fixed.

Since the piping equipment A and the closing plate 31 are both made of metal, they are not only easy to weld and bolt, but also advantageous against temperature shrinkage.

To attach the inner lid 3, a packing material P1 is interposed between the lower surface of the closing plate 31 and the flange 13, and a sealing material 4 is placed between the upper surface of the closing plate 31 and the outer periphery of the flange 13.

Then, bolts are inserted into the flange 13 from the side of the elongated hole formed in the closing plate 31, and the inner cover 3 is attached while being allowed to slide in the horizontal direction.

Further, it is preferable to interpose a buffer material 5 made of a known material between the reinforcing tube 32 and the circumferential surface of the small diameter surface 16.

As described above, the inner lid 3 is attached to the opening 12 to close the inner tank 1 and form a completely sealed body.

It is also possible to place the sliding surface 34 of the vertical plate 33 directly on the top surface of the flange 13, as shown in FIG.

<D> Outer tank (Figures 1 and 3) The outer tank 2 is a protective shell made of concrete for the purpose of housing and protecting the inner tank 1 inside.

An opening 22 is formed in the roof of the outer tank 2 on the same perpendicular line as the opening 12 of the inner tank.

In order to guide the piping equipment A out of the tank, the surroundings of the piping equipment A are sufficiently covered with a heat insulating material 6, and
The opening 22 is closed with a closing plate 23 made of a circular stainless steel plate.

The penetrating portion of the piping equipment A that penetrates the closing plate 23 is not fixed and is sealed to such an extent that the outer tank 2 can be kept airtight while allowing vertical sliding.

<Function> Next, the items required for the buffer function in a general double-shell cryogenic storage tank will be explained.

<B> Conditions for double-shell cryogenic storage tank The following items are required as a buffer function for a general double-shell cryogenic storage tank.

(a) Capable of absorbing deformation due to temperature shrinkage difference between the inner tank and piping, etc.

(b) The deformation of the inner tank and piping during an earthquake can be controlled.

(c) Deformation of the inner and outer tanks during an earthquake can be controlled.

(d) Capable of absorbing deformation due to temperature contraction of the outer tank and piping, etc.

(e) Deformation of the outer tank and piping during an earthquake can be controlled.

(f) Maintain good cold insulation effect and airtightness.

The above items will be specifically examined regarding the concrete double-shell cryogenic storage tank of the present invention.

<B> Regarding item (a) In the present invention, the piping equipment A etc. are fixed to the inner cover 3 made of the same material as the piping equipment A etc.

Therefore, the amount of temperature contraction of the piping equipment A, etc. and the inner cover 3 is almost equal, and there is no fear that the piping equipment A or the inner lid 3 will be damaged due to temperature contraction.

Furthermore, since the inner lid 3 and the inner tank 1 are configured to allow horizontal sliding between them, deformation of the inner lid 3 will not have an adverse effect on the inner tank 1.

<B> Regarding item (b), the space between the inner cover 3 and the inner tank 1 from which the piping equipment A hangs is slidable, and the buffer material 5 is interposed between the circumferential surfaces of the inner cover 3 and the inner tank 1. Therefore, it is possible to more safely absorb the behavior during earthquakes.

<C> Regarding items (c) to (e), the inner tank 1 and the outer tank 2 were constructed separately rather than as an integral structure.

Therefore, deformations caused by earthquakes or temperature contraction are not transmitted to each other.

Further, since the outer peripheral surface of the piping equipment A is covered with a heat insulating material 6, deformation caused by an earthquake or temperature contraction can be absorbed by the heat insulating material 6.

<D> Regarding (f) All the equipment piping attachment parts are treated at the top of the inner tank 2, and the insulation material 6 is interposed between the entire circumferential surfaces of the inner tank 1 and the outer tank 2, so that a good Can maintain cold effect.

<Other Embodiments> (FIG. 5) In the embodiment described above, various equipment A, B, etc. are suspended in the inner tank 1, but they may also be suspended in the outer tank 2.

That is, the outer flange 23 is erected by providing a step in the opening 22 portion of the outer tank 2 in the same manner as the shape of the flange 13 at the top of the inner tank 1 in the embodiment described above.
Horizontal support surface 24 on the way to the inner periphery of the outer flange 23
form.

Then, insert the inner cover 3 with the piping equipment A etc. fixed into this opening 22, and then
4 is placed on the horizontal support surface 24, and in order to prevent the outer circumference of the reinforcing tube 32 from colliding with the inner circumferential surfaces of the inner and outer tubs 1 and 2, a buffer material 5 is attached to either one of them.

Furthermore, with the protective cover 7 that penetrates the piping equipment A,
The outer flange 23 is closed, and a heat insulating material 6 is filled between the protective lid 7 and the closing plate 31 to maintain airtightness and heat retention of the storage tank.

According to this embodiment, not only can the piping equipment A and the like be suspended into the outer tank 2, but also deformation caused by temperature contraction and earthquakes can be absorbed by sliding between the horizontal support surface 24 and the guide surface 34.

Further, in order to prevent collision between the outer periphery of the reinforcing tube 32 and the inner circumferential surfaces of the inner and outer tubs 1 and 2, a buffer material 5 is attached to either one of them.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be obtained.

<B> Conventional storage tanks with a double structure made of steel for both the inner and outer tanks have a problem in terms of construction costs, while on the other hand, storage tanks with a double structure made of concrete for both the inner and outer tanks have problems in terms of safety against temperature shrinkage and earthquakes. There was a problem.

The present invention can simultaneously reduce costs and improve safety against temperature shrinkage and earthquakes, which have not been possible in the past.

<B> By placing the inner tank inside the outer tank, deformations occurring in both the inner and outer tanks and deformations occurring in various piping equipment etc. can be absorbed without restraint.

[Brief explanation of drawings]

Figure 1: A longitudinal cross-sectional view of the concrete double shell storage tank according to the present invention, Figure 2: An explanatory diagram of the structure for closing the opening of the inner tank, Figure 3: The closed state of the opening of the inner and outer tanks. FIG. 4: An explanatory diagram of another hanging structure for hanging piping equipment; FIG. 5: An explanatory diagram of another embodiment. 1: Inner tank, 2: Outer tank, 3: Inner lid, 4: Sealing material, 5: Cushioning material.

Claims (1)

[Scope of Claims] 1. An inner tank with a sealed structure made of concrete is placed and housed in an outer tank with a sealed structure made of concrete, a heat insulating material is interposed between the entire circumferential surfaces of both tanks, and the tank is filled with liquid. In a concrete double-shell storage tank where piping equipment for receiving and discharging water is suspended, openings are opened on the same perpendicular line of each dome of both tanks, and the opening on the outer tank side is a lid for the outer tank that penetrates the piping equipment. The metal cover for the inner tank is fixed to the inner tank by passing the piping equipment through it, and the inner tank cover is attached to the opening of the inner tank or outer tank. A double-shell concrete low-temperature storage tank, which is slidably placed on the top surface and is characterized by having a sealing material between the lid material for the inner tank and the opening.