JPH0473038B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a low-temperature tank, and in particular, by fixing the free end of a membrane to an annular leaf spring member provided at the upper end of a concrete tank body, thermal expansion and contraction of the membrane can be controlled by the leaf spring member. The present invention relates to a low-temperature tank that absorbs stress through elastic deformation or bending deformation, and is capable of relieving stress in a membrane with a simple structure.

As a low-temperature tank for storing low-temperature liquids such as LNG,
It is known that a concrete tank is formed in the shape of a cylinder with a bottom, and a membrane, which is a thin steel plate, is stretched over the inner wall of the tank with a cold insulating material interposed therebetween.

By the way, when a membrane is stretched on the inner wall of a tank body, particularly on a side wall, conventionally, anchors or the like are buried in the side wall and the membrane is welded and fixed thereto to prevent the membrane from peeling off from the tank body. For this reason,
Construction of tanks was time-consuming, leading to longer construction times and higher costs. In particular, membranes undergo thermal contraction when they come into contact with low-temperature liquids, and thermal expansion during warm-up. Therefore, the membrane fixed with anchors or the like as described above must be provided with corrugations vertically and horizontally to absorb thermal expansion and contraction, resulting in high costs.

Therefore, the present invention was devised to solve the above problems, and its purpose is to be able to absorb thermal expansion and contraction in the height direction of the membrane without requiring corrugations, simplify the structure,
An object of the present invention is to provide a low-temperature tank that can shorten tank construction period and reduce costs.

In order to achieve the above object, the present invention embeds a buried ring in the upper end of a concrete tank body, fixes a roof covering the tank body to the buried ring, and contacts the upper end of the tank body so that it can be placed inside the tank body in the radial direction. An annular leaf spring member extending in the direction is fixed, a downwardly curved curved surface portion is formed on the inner edge of the leaf spring member, and a plurality of notches are provided to prevent the deformation of the leaf spring member on the inner edge of the upper end of the tank body. The lower end of the membrane provided along the inner surface of the tank body is fixed to the tank body, and the upper end of the membrane is stacked on the curved surface of the leaf spring member so as to cover it from above. It is characterized by being fixed.

According to the above configuration, the leaf spring member fixed to the buried ring not only seals the gas of the low-temperature liquid, but also supports the membrane and absorbs thermal expansion and contraction in the height direction. There is no need for anchors to be fixed to the side walls or corrugations to absorb thermal deformation in the height direction, reducing construction time and manufacturing costs. In this case, since the notch is provided at the inner edge of the upper end of the tank and the plurality of notches are provided at the inner edge of the leaf spring member, the leaf spring member can be easily bent and deformed. Also,
Since the outer edge of the leaf spring member is in contact with the upper end of the tank body, stress is not concentrated at the joint between the embedded ring and the leaf spring member. Moreover, since a downwardly curved curved surface is formed on the inner edge of the leaf spring member, and the upper end of the membrane is overlapped and fixed on top of this curved surface so as to cover this curved surface, the joint between the leaf spring member and the membrane can also be used. There is no stress concentration, and overall durability can be improved.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In Fig. 1, reference numeral 1 denotes a concrete tank body formed into a cylindrical shape with a bottom, and an inner edge portion which is annular along the circumferential direction and extends radially inward at the upper end of the tank body is a free end. A leaf spring member 2 is provided. In order to fix the leaf spring member 2 to the tank body 1, an embedded ring 3 made of a single section steel is embedded in an annular shape along the circumferential direction at the upper end of the tank body, and the upper flange of this embedded ring 3 An outer edge portion, which is the base end portion of the leaf spring member 2, is welded and fixed to the edge of the leaf spring member 2.

A notch 4 is formed at the inner edge of the upper end of the tank body 1 so that the free end 2a of the leaf spring member 2 in contact with the upper end of the tank body 1 can easily move up and down using the base end 2b as a fulcrum. In addition, as shown in FIG. 2, cuts 5 are formed at appropriate intervals in the free end 2a of the leaf spring member 2. A membrane 7 is stretched over the inner wall of the tank body 1 via a cold insulator 6, and the free end 7a of the membrane 7 rising along the side wall 1a of the tank body 1 is connected to the leaf spring member 2. Free end 2
It is fixed at a. Specifically, a plate-shaped cold insulating material 6 made of urethane foam or the like is first spread and fixed on the inner wall of the tank body 1, and a membrane 7 is stretched airtightly over this cold insulating material 6 so as to cover it. . The membrane 7 is fixed to an anchor 8 buried in the bottom wall 1b of the tank 1, and the portion rising along the side wall 1a of the tank 1 is free. Therefore, the membrane 7 can freely expand and contract in the height direction, and this expansion and contraction causes the leaf spring member 2 to expand and contract.
This will be absorbed by the bending deformation of the free end 2a.

Note that the membrane on the bottom wall 1b is anchor 8.
Since the movement is restrained by the membrane, corrugations are formed as appropriate in the vertical and horizontal directions, and since the membrane of the side wall 1a is restrained from moving only in the circumferential direction, only vertical corrugations 9 are formed (see Fig. 2). .

The free end portion 2a of the leaf spring member 2 is curved downward so as to have a curved tip so as not to damage the membrane 7 fixed thereto.
The free end portion 7a is overlapped with the curved surface portion 10 so as to cover it from above and fixed airtightly by welding. In FIG. 1, reference numeral 11 is a dome-shaped roof that covers the tank body 1, and its peripheral edge is fixed to the embedded ring 3.

According to such a structure, even if the membrane 7 in the side wall 1a portion undergoes thermal expansion or thermal contraction, the leaf spring member 2, which is the fixed end thereof, follows and bends and deforms, thereby preventing the movement of the membrane 7. It can be tolerated or absorbed, creating little stress on the membrane. The membrane 7 on the side wall portion is fixed to the free end 2a of the leaf spring member 2.
This is because it can be easily performed without using an anchor or the like by simply welding the free end 7a of the membrane 7. The tank construction period can be shortened, and there is no need for anchors or horizontal corrugations to absorb thermal deformation in the height direction.
Manufacturing costs can be reduced.

In summary, the present invention exhibits the following excellent effects.

(1) The leaf spring member fixed to the buried ring not only provides a gas seal for the low-temperature liquid, but also supports the membrane and absorbs thermal expansion and contraction in its height direction, making it possible to fix the membrane to the side wall of the tank body. This eliminates the need for anchors to absorb thermal deformation in the height direction and corrugations to absorb thermal deformation in the height direction, resulting in shorter construction times and lower manufacturing costs.

(2) In this case, since the notch is provided at the inner edge of the upper end of the tank and the plurality of notches are provided at the inner edge of the leaf spring member, the leaf spring member can be easily bent and deformed. Further, since the outer edge of the leaf spring member is in contact with the upper end of the tank body, stress is not concentrated at the joint between the embedded ring and the leaf spring member. Moreover, since a downwardly curved curved surface is formed on the inner edge of the leaf spring member, and the upper end of the membrane is overlapped and fixed on top of this curved surface so as to cover this curved surface, the joint between the leaf spring member and the membrane can also be used. There is no stress concentration, and overall durability can be improved.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a partial sectional view of a low temperature tank, and FIG. 2 is a partial perspective view of the same. In the figure, 1 is a tank body, 2 is a leaf spring member, and 7 is a membrane.

Claims (1)

[Claims] 1. A buried ring is buried in the upper end of the concrete tank, and a roof covering the tank is fixed to the buried ring, and an annular leaf spring member that contacts the upper end of the tank and extends radially inward. is fixed, a downwardly curved curved surface portion is formed on the inner edge of the leaf spring member, and a plurality of notches are provided, and a notch is provided on the inner edge of the upper end of the tank body to allow deformation of the leaf spring member, and the tank body is fixed. A low-temperature tank characterized in that the lower end of a membrane provided along the inner surface of the tank is fixed to the tank body, and the upper end of the membrane is fixed to the curved surface of the leaf spring member so as to cover it from above. .