Multi-shell tank

Abstract

This multi-shell tank comprises: an inner tank; an outer tank surrounding the inner tank; a support skirt that has a cylindrical shape and extends vertically from the outer wall of the inner tank to a foundation; and a connection ring constituting part of the support skirt and the outer tank. The support skirt includes a first skirt member and a second skirt member separated by the connection ring. The outer tank includes a first outer tank member and a second outer tank member separated by the connection ring.

Description

[Technical Field]

[0001] The present disclosure relates to multi-shell tanks, and more particularly to support structures for multi-shell tanks. [Background technology]

[0002] Multi-shell tanks for storing low-temperature liquefied gas have been known for some time. A multi-shell tank includes an inner tank and an outer tank surrounding the inner tank. Among multi-shell tanks, there is one in which the inner tank is supported by a cylindrical support member called a support skirt. Patent Document 1 discloses this type of multi-shell tank.

[0003] The multi-shell tank of Patent Document 1 comprises an inner vessel and an outer vessel surrounding the inner vessel via an insulation layer, and the inner and outer vessels are supported on a foundation by a cylindrical support skirt that penetrates the bottom end of the outer vessel and reaches the inner vessel. The outer vessel is composed of a hemispherical outer vessel roof plate, cylindrical outer vessel side plates, an outer vessel shell plate, and an outer vessel bottom plate. A ring-shaped bottom plate connecting member is fixed to the inner periphery of the support skirt, and the outer vessel bottom plate is placed on a beam member attached to this bottom plate connecting member. In addition, a ring-shaped shell plate connecting member is fixed to the outer periphery of the support skirt, and the lower end of the outer vessel shell plate is connected to this shell plate connecting member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-54033 A (Figs. 4 and 6) Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, when the support skirt penetrates the outer vessel, the outer vessel and the support skirt intersect in a crisscross pattern in a vertical cross section, and the space around the intersection of the outer vessel and the support skirt is narrow. When welding work is performed on site from both sides of the joint in such a narrow space, it is difficult to secure sufficient working space, making the work complicated, and it is also difficult to perform non-destructive testing to check the welding condition.

[0006] The present disclosure has been made in consideration of the above circumstances, and its purpose is to provide a structure for a multi-shell tank having an inner and outer shell, in which a support skirt supporting the inner shell is arranged to penetrate the outer shell, that can avoid welding work in a narrow space where the outer shell and the support skirt intersect. [Means for solving the problem]

[0007] In order to solve the above problems, a multi-shell tank according to one aspect of the present disclosure comprises: An inner tank, an outer tank surrounding the inner tank; a cylindrical support skirt extending in the vertical direction from the outer wall of the inner tank to the foundation; a connecting ring that forms a part of the support skirt and the outer tank; The support skirt has a first skirt member and a second skirt member separated by the connecting ring, and the outer tank has a first outer tank member and a second outer tank member separated by the connecting ring. death, The connecting ring includes a cylindrical base portion having a first skirt joint at its lower end to which the first skirt member is joined and a second skirt joint at its upper end to which the second skirt member is joined, an inner ring portion or inner cylindrical portion having a first outer tank joint at its tip to which the first outer tank member is joined and protruding inward from the base, and an outer ring portion having a second outer tank joint at its tip to which the second outer tank member is joined and protruding outward from the base. That is why. A multi-shell tank according to another aspect of the present disclosure includes: An inner tank, an outer tank surrounding the inner tank; a cylindrical support skirt extending in the vertical direction from the outer wall of the inner tank to the foundation; a connecting ring that forms a part of the support skirt and the outer tank; the support skirt has a first skirt member and a second skirt member separated by the connecting ring, and the outer tank has a first outer tank member and a second outer tank member separated by the connecting ring; The connecting ring has a first skirt joint to which the first skirt member is joined, a first outer tank joint to which the first outer tank member is joined, and a second outer tank joint to which the second outer tank member is joined, and the second skirt member is joined to the second outer tank member. A multi-shell tank according to yet another aspect of the present disclosure includes: An inner tank, an outer tank surrounding the inner tank; a cylindrical support skirt extending in the vertical direction from the outer wall of the inner tank to the foundation; a connecting ring that forms a part of the support skirt and the outer tank; the support skirt has a first skirt member and a second skirt member separated by the connecting ring, and the outer tank has a first outer tank member and a second outer tank member separated by the connecting ring; The connecting ring has a first skirt joint to which the first skirt member is joined, a first outer tank joint to which the first outer tank member is joined, and a second skirt joint to which the second skirt member is joined, and the second outer tank member is joined to the second skirt member. A multi-shell tank according to yet another aspect of the present disclosure includes: An inner tank, an outer tank surrounding the inner tank; a cylindrical support skirt extending in the vertical direction from the outer wall of the inner tank to the foundation; a connecting ring that forms a part of the support skirt and the outer tank; the support skirt has a first skirt member and a second skirt member separated by the connecting ring, and the outer tank has a first outer tank member and a second outer tank member separated by the connecting ring; The vertical cross section of the connecting ring is rectangular with chamfered outer upper corners and inner lower corners, and includes a second skirt joint portion located at the upper part of the rectangle to which the second skirt member is joined, a first skirt joint portion located at the lower part of the rectangle to which the first skirt member is joined, a second outer tank joint portion located at the chamfered corner surface of the outer upper corner of the rectangle to which the second outer tank member is joined, and a first outer tank joint portion located at the chamfered corner surface of the inner lower corner of the rectangle to which the first outer tank member is joined. [Effects of the Invention]

[0008] According to the present disclosure, in a multi-shell tank having an inner tank and an outer tank, in which a support skirt supporting the inner tank is arranged to penetrate the outer tank, a structure can be provided that can avoid welding work in the narrow area where the outer tank and the support skirt intersect. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a vertical cross-sectional view of a multi-shell tank according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is an enlarged vertical cross-sectional view of the connection between the outer tank and the support skirt. [Figure 3] FIG. 3 is an enlarged vertical cross-sectional view of a connection portion between an outer tank and a support skirt using a connection ring according to the first modification. [Figure 4] FIG. 4 is an enlarged vertical cross-sectional view of a connection portion between the outer tank and the support skirt using a connection ring according to the second modification. [Figure 5] FIG. 5 is an enlarged vertical cross-sectional view of a connection portion between the outer tank and the support skirt using a connection ring according to the third modification. [Figure 6] FIG. 6 is an enlarged vertical cross-sectional view of a connection portion between the outer tank and the support skirt using a connection ring according to the fourth modification. [Figure 7] FIG. 7 is an enlarged vertical cross-sectional view of a connection portion between an outer tank and a support skirt using a connection ring according to the fifth modified example. [Figure 8] FIG. 8 is an enlarged vertical cross-sectional view of a connection portion between the outer tank and the support skirt using a connection ring according to the fifth modification. [Figure 9] FIG. 9 is an enlarged vertical cross-sectional view of a connection portion between the outer tank and the support skirt using a connection ring according to the sixth modification. [Figure 10] FIG. 10 is an enlarged vertical cross-sectional view of a connection portion between the outer tank and the support skirt using a connection ring according to the sixth modification. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a multi-shell tank 1 according to an embodiment of the present disclosure. The multi-shell tank 1 shown in FIG. 1 is a cryogenic container for storing low-temperature liquefied gas such as liquefied hydrogen or liquefied natural gas. The multi-shell tank 1 is supported on a foundation 10 via a support skirt 2. The foundation 10 may be, for example, the hull of a liquefied gas carrier or a concrete base installed on the ground.

[0011] The multi-shell tank 1 is a spherical tank. However, the multi-shell tank 1 is not limited to a spherical tank, and may be a deformed spherical tank having a prolate ellipsoid shape, a stretch tank with upper and lower hemispherical shapes and a cylindrical section in between, or a rectangular tank having a rectangular parallelepiped shape. The multi-shell tank 1 includes an inner tank 3 containing liquefied gas and an outer tank 4 surrounding the inner tank 3. The inner tank 3 and the outer tank 4 are radially separated, and an insulating layer is formed between the inner and outer tanks. An insulating material may be filled between the inner and outer tanks, or a vacuum insulating layer may be formed between the inner and outer tanks. Note that while the multi-shell tank 1 according to this embodiment is a double-shell tank including the inner tank 3 and the outer tank 4, the present disclosure is also applicable to a multi-shell tank 1 having three or more multiple tanks.

[0012] The outer shell 4 comprises an outer shell lower shell 41, an outer shell upper shell 42, and a connecting ring 5 that connects the outer shell lower shell 41 and the outer shell upper shell 42. The outer shell lower shell 41 and the outer shell upper shell 42 are separated in the vertical direction by the connecting ring 5. When the outer shell 4 has a spherical shell shape as a whole, when the sphere of the outer shell 4 is cut along a horizontal cutting plane located between the equator and the lower pole and divided into an upper part and a lower part, the upper part (i.e., the spherical indentation part) corresponds to the outer shell upper shell 42, and the lower part (i.e., the spherical crown part) corresponds to the outer shell lower shell 41.

[0013] The support skirt 2 has a cylindrical shape extending vertically from the outer wall of the inner tank 3 to the foundation 10. The support skirt 2 includes a lower skirt 21, an upper skirt 22, and a connecting ring 5 connecting the lower skirt 21 and the upper skirt 22. The lower skirt 21 and the upper skirt 22 are separated vertically by the connecting ring 5. The connecting ring 5 serves as both a component of the support skirt 2 and a component of the outer tank 4. The upper skirt 22 and the lower skirt 21 are substantially concentric cylindrical bodies. The upper end of the upper skirt 22 is joined to the outer wall of the inner tank 3 around its equator. The lower end 221 of the upper skirt 22 is connected to the upper end 211 of the lower skirt 21 via the connecting ring 5. The connection between the upper skirt 22 and the connecting ring 5 is not limited to being directly joined to the upper skirt 22 and the connecting ring 5; the upper skirt 22 and the connecting ring 5 may be connected via a component of the outer tank 4. The lower end of the lower skirt 21 is joined to the foundation 10, and the lower skirt 21 is erected on the foundation 10.

[0014] An upper edge 411 of the outer shell lower shell 41 is joined to the connecting ring 5, and the outer shell lower shell 41 is supported by the support skirt 2 via the connecting ring 5. A lower edge 421 of the outer shell upper shell 42 is joined to the connecting ring 5, and the outer shell upper shell 42 is supported by the support skirt 2 via the connecting ring 5.

[0015] [Connection structure between outer tub 4 and support skirt 2] Here, the connection structure between the outer tank 4 and the support skirt 2 will be described in detail. Figure 2 is an enlarged vertical cross-sectional view of the connection portion between the outer tank 4 and the support skirt 2. As shown in Figure 2, the connection ring 5 has a first skirt joint 61, a second skirt joint 62, a first outer tank joint 64, and a second outer tank joint 63. One of the second skirt joint 62 and the first outer tank joint 64 may be omitted from the connection ring 5.

[0016] The first skirt joint 61 is an annular joining surface provided on the lower part of the connecting ring 5. The first skirt joint 61 is joined to the upper end 211 of the lower skirt 21. The joining method between the first skirt joint 61 and the lower skirt 21 is, for example, welding (including fusion welding, pressure welding, and brazing). The second skirt joint 62 is an annular joining surface provided on the upper part of the connecting ring 5. The second skirt joint 62 is joined to the lower end 221 of the upper skirt 22. The joining method between the second skirt joint 62 and the upper skirt 22 is, for example, welding. The first outer cell joint 64 is an annular joining surface provided on the inner periphery of the connecting ring 5. The first outer cell joint 64 is joined to the upper edge 411 of the outer cell lower shell 41. The joining method between the first outer cell joint 64 and the outer cell lower shell 41 is, for example, welding. The second outer cell joint 63 is an annular joining surface provided on the outer periphery of the connecting ring 5. The second outer vessel joint 63 is joined to the lower edge 421 of the outer vessel upper shell 42. The second outer vessel joint 63 and the outer vessel upper shell 42 are joined by, for example, welding.

[0017] The connecting ring 5 not only connects the lower skirt 21 and the upper skirt 22, but also connects the outer shell upper shell 42 and the outer shell lower shell 41, so it is required to have high strength because extremely large stresses are generated. The connecting ring 5 has a divided structure consisting of multiple arc blocks arranged in the circumferential direction, and is formed into a ring shape by joining the multiple arc blocks. To ensure sufficient strength for the connecting ring 5, it is desirable that each arc block, which is a component of the connecting ring 5, is a single piece made by cutting out a thick plate material.

[0018] 2 integrally includes a cylindrical base portion 50 extending in the vertical direction, an outer ring portion 53 protruding outward from the outer wall of the base portion 50, and an inner ring portion 54 protruding inward from the inner wall of the base portion 50. Here, the radial direction toward the center of the ring of the connection ring 5 is referred to as the "inward direction," and the radial direction opposite to the inward direction is referred to as the "outward direction."

[0019] The base 50 of the connecting ring 5A is a cylinder arranged concentrically with the lower skirt 21 and the upper skirt 22. The base 50 of the connecting ring 5A fills the gap between the lower skirt 21 and the upper skirt 22, which are spaced apart in the vertical direction. In other words, part of the support skirt 2 is replaced by the connecting ring 5A. A second skirt joint 62 is provided at the upper end of the base 50, and a first skirt joint 61 is provided at the lower end of the base 50. The first skirt joint 61 and the second skirt joint 62 are spaced apart in the vertical direction by a distance greater than the maximum thickness of the outer tub 4.

[0020] The vertical cross section of the outer ring portion 53 and inner ring portion 54 of the connecting ring 5A is a continuous arc. The space between the outer shell upper shell 42 and the outer shell lower shell 41, which are spaced apart in the vertical direction, is blocked by a portion of the spherical shell formed by the outer ring portion 53, the base portion 50, and the inner ring portion 54. In other words, a portion of the spherical shell of the outer shell 4 is replaced by the connecting ring 5A. A second outer shell joining portion 63 is provided at the tip of the outer ring portion 53, and a first outer shell joining portion 64 is provided at the tip of the inner ring portion 54. The second outer shell joining portion 63 and the first outer shell joining portion 64 are spaced apart in the vertical direction by a distance greater than the maximum thickness of the outer shell 4 and a distance greater than the maximum thickness of the support skirt 2 in the radial direction. Furthermore, in the connecting ring 5A, the second outer shell joining portion 63 is positioned higher than the second skirt joining portion 62, and the second outer shell joining portion 63 and the second skirt joining portion 62 are spaced apart in the vertical direction. Furthermore, the first outer tank joint 64 is positioned lower than the first skirt joint 61, and the first outer tank joint 64 and the first skirt joint 61 are spaced apart in the vertical direction. However, the second outer tank joint 63 may be positioned lower than the second skirt joint 62, and the first outer tank joint 64 may be positioned higher than the first skirt joint 61.

[0021] In the connecting ring 5A configured as described above, the first skirt joint 61, the second skirt joint 62, the first outer tank joint 64, and the second outer tank joint 63 are each spaced apart from the apparent intersection C between the outer tank 4 and the support skirt 2. The apparent intersection C is the intersection line when the outer tank 4 is a continuous spherical shell and the support skirt 2 is a continuous cylindrical body. The space between the outer tank 4 and the support skirt 2 becomes narrower as it approaches the apparent intersection C. In the connecting ring 5A, the space between the base 50 and the base end of the outer ring portion 53 is narrow, but the second skirt joint 62 at the upper end of the base 50 and the second outer tank joint 63 at the tip of the outer ring portion 53 are spaced apart in the vertical and radial directions. Therefore, the joining portion between the second skirt joint 62 and the upper skirt 22 at the work site is removed from a narrow space, ensuring space for the joining work of the second skirt joint 62 and the upper skirt 22 and also enabling non-destructive testing of these joining portions. Similarly, the joining portion between the second outer vessel joint 63 and the outer vessel upper shell 42 at the work site is removed from a narrow space, also enabling non-destructive testing of these joining portions.

[0022] In the connecting ring 5A, the space between the base 50 and the base end of the inner ring 54 is narrow, but the first skirt joint 61 at the lower end of the base 50 and the first outer tank joint 64 at the tip of the inner ring 54 are spaced apart in the vertical and radial directions. Therefore, the joint between the first skirt joint 61 and the lower skirt 21 on site is retracted from the narrow space, ensuring space for the joining work of the first skirt joint 61 and the lower skirt 21 and also enabling non-destructive testing of these joints. Similarly, the joint between the first outer tank joint 64 and the outer tank lower shell 41 on site is retracted from the narrow space, also enabling non-destructive testing of these joints.

[0023] The following describes modified examples of the connection ring 5. In the description of the modified examples, the same or similar members as those in the above-described embodiment are denoted by the same reference numerals in the drawings, and detailed description thereof will be omitted.

[0024] [Modification 1 of the connection ring 5] FIG. 3 is an enlarged vertical cross-sectional view of the connection between the outer tank 4 and the support skirt 2 using a connecting ring 5B according to Modification 1. In the connecting ring 5A shown in FIG. 2, the vertical cross sections of the outer ring portion 53 and the inner ring portion 54 form a continuous arc through the base 50. In contrast, in the connecting ring 5B shown in FIG. 3, the vertical cross sections of the outer ring portion 53 and the inner ring portion 54 are both arcs, but the outer ring portion 53 and the inner ring portion 54 are not continuous arcs but are offset in the vertical direction. In this connecting ring 5B, the connection points of the outer ring portion 53 and the inner ring portion 54 on the base 50 are vertically spaced apart. This suppresses deformation of the connecting ring 5B due to loads such as pressure and alleviates stress compared to when the outer ring portion 53 and the inner ring portion 54 are connected at the same vertical position. Furthermore, the connecting ring 5B can be produced by dividing it into an upper segment including one of the outer ring portion 53 and the inner ring portion 54 and a lower segment including the other of the outer ring portion 53 and the inner ring portion 54. In this case, each segment is formed by cutting out from a thick plate, and these segments are joined together to create the connecting ring 5B. By dividing the connecting ring 5B into an upper segment and a lower segment, the amount by which each segment protrudes from the base 50 is reduced, making it easier to cut out from the thick plate. In the connecting ring 5B shown in FIG. 3, the connection point of the inner ring portion 54 is lower than the connection point of the outer ring portion 53 on the base 50, but the connection point of the inner ring portion 54 may also be higher than the connection point of the outer ring portion 53 on the base 50.

[0025] [Modification 2 of the connection ring 5] FIG. 4 is an enlarged vertical cross-sectional view of the connection between the outer tank 4 and the support skirt 2 using a connecting ring 5C according to Modification 2. In the connecting ring 5A shown in FIG. 2, the vertical cross sections of the outer ring portion 53 and the inner ring portion 54 are both arc-shaped. In contrast, in the connecting ring 5C shown in FIG. 4, the vertical cross sections of the outer ring portion 53 and the inner ring portion 54 include linear portions extending vertically. More specifically, the outer ring portion 53 of the connecting ring 5C integrally includes an annular portion extending outward from the base portion 50 and a cylindrical portion extending upward from the outer edge of the annular portion. Similarly, the inner ring portion 54 of the connecting ring 5C integrally includes an annular portion extending inward from the base portion 50 and a cylindrical portion extending downward from the inner edge of the annular portion. Such a connecting ring 5C can be produced by dividing it into an upper segment including the outer ring portion 53 and a lower segment including the other half of the inner ring portion 54. In this case, each segment is machined from a thick plate and joined together to form the connecting ring 5C. By being able to separate the upper and lower segments, the amount of radial protrusion of the outer ring portion 53 and the inner ring portion 54 from the base portion 50 in each segment can be reduced, while the second outer-cell joint portion 63 and the first outer-cell joint portion 64 in the connecting ring 5C can be spaced apart significantly in the vertical direction.

[0026] [Modification 3 of the connection ring 5] 5 is an enlarged vertical cross-sectional view of the connection between the outer tank 4 and the support skirt 2 using a connection ring 5D according to Modification 3. In the connection ring 5D shown in FIG. 5, the first skirt joint 61 and the second skirt joint 62 are concentrically arranged, but the diameter of the first skirt joint 61 is larger than the diameter of the second skirt joint 62. In other words, the second skirt joint 62 and the first skirt joint 61 are offset in the radial direction. Therefore, the cylindrical body constituting the base 50 gradually expands in diameter midway between the top and bottom, and the base 50 has a lower base 51 and an upper base 52 with a smaller diameter than the lower base 51.

[0027] Furthermore, the connecting ring 5D according to the third modification has an inner cylindrical portion 56 that protrudes downward from the inner wall of the base portion 50, instead of the inner ring portion 54. A first outer tank joint portion 64 is provided at the tip of the inner cylindrical portion 56. The inner cylindrical portion 56 and the upper base portion 52 are concentrically arranged cylinders of substantially the same diameter. In this type of connecting ring 5D, the amount of radial protrusion inward from the base portion 50 can be reduced. By reducing the amount of radial protrusion from the base portion 50, cutting is facilitated when producing the arc blocks that are components of the connecting ring 5D from thick plate material.

[0028] Furthermore, in the connecting ring 5D according to the third modification, the outer ring portion 53 protruding outward from the base portion 50 has a horizontal surface. In such a connecting ring 5D, an operator can use the outer ring portion 53 as a work area to perform the joining work between the second outer tank joint portion 63 and the outer tank upper shell 42. In the arc block that is a component of the connecting ring 5D, a formed body including the base portion 50 and the inner ring portion 54 may be formed by cutting out a thick plate material, and the plate material that will become the outer ring portion 53 may be joined to this formed body by welding or the like.

[0029] [Modification 4 of the connection ring 5] Fig. 6 is an enlarged vertical cross-sectional view of the connection between the outer tank 4 and the support skirt 2 using a connecting ring 5E according to Modification 4. The connecting ring 5E shown in Fig. 6 is a further modification of the connecting ring 5D shown in Fig. 5, in which the distinct outer ring portion 53 protruding outward from the outer wall of the base 50 is omitted, and a second outer tank joint portion 63 is formed on the outer wall surface of the base 50, and this second outer tank joint portion 63 is positioned lower than the second skirt joint portion 62. With this type of connecting ring 5E, the amount of radial protrusion inward and outward from the base 50 is reduced, facilitating cutting when producing the arc blocks that are components of the connecting ring 5E from thick plate material.

[0030] [Modification 5 of the connection ring 5] FIG. 7 is an enlarged vertical cross-sectional view of the connection between the outer tank 4 and the support skirt 2 using a connecting ring 5F according to Modification 5. In the connecting ring 5F shown in FIG. 7, a first skirt joint 61, a second skirt joint 62, a second outer tank joint 63, and a first outer tank joint 64 are provided on the base 50. In other words, the connecting ring 5F does not have the outer ring 53 and inner ring 54 of the connecting ring 5A shown in FIG. 2. The vertical cross-section of the base 50 of the connecting ring 5F is rectangular, with the inner lower corner and outer upper corner chamfered. A second skirt joint 62 is provided on the upper surface of the base 50, and a first skirt joint 61 is provided on the lower surface of the base 50. A first outer tank joint 64 is provided on the corner surface of the inner lower corner of the base 50. A second outer tank joint 63 is provided on the corner surface of the outer upper corner of the base 50. The distance between the first skirt joint 61 and the second skirt joint 62 is adjusted by adjusting the vertical height of the base 50. The distance between the second outer vessel joint 63 and the first outer vessel joint 64 is adjusted by the plate thickness of the base 50. For example, as shown in Fig. 8, the vertical cross section of the base 50 of the connecting ring 5F may be a rectangular shape that is flat in the vertical direction. With such a connecting ring 5F, cutting work is extremely easy when producing the arc blocks, which are components of the connecting ring 5G, from thick plate material.

[0031] [Modification 6 of the connecting ring 5] Figure 9 is an enlarged vertical cross-sectional view of the connection between the outer tank 4 and the support skirt 2 using a connection ring 5G according to Modification 6. The connection ring 5G shown in Figure 9 has a ring-shaped base 50 extending in the vertical direction, with a second outer tank joint 63 located at the upper end of the base 50 and a first skirt joint 61 located at the lower end of the base 50. The connection ring 5G also has an inner cylindrical portion 56 extending downward from the inner wall of the base 50. A first outer tank joint 64 is located at the lower end of the inner cylindrical portion 56.

[0032] The outer vessel 4 includes an outer vessel lower shell 41 as a first outer vessel member, an annular plate 43 as a second outer vessel member, and an outer vessel upper shell 42 as a third outer vessel member. Not only in this modification, but also in the other modifications 1 to 5, the outer vessel 4 may have the annular plate 43 as a second outer vessel member, and the annular plate 43 may be joined to the second outer vessel joining portion 63 of the connecting ring 5.

[0033] The annular plate 43 is placed on the second outer vessel joint 63 of the connecting ring 5G and joined to the second outer vessel joint 63. The lower edge 421 of the outer vessel upper shell 42 is joined to the upper surface of the annular plate 43, and the space between the connecting ring 5G and the outer vessel upper shell 42 is closed by the annular plate 43. In addition, the lower end 221 of the upper skirt 22 is joined to the upper surface of the annular plate 43 above the second outer vessel joint 63 of the connecting ring 5G. In other words, the annular plate 43 is sandwiched vertically between the connecting ring 5G and the upper skirt 22, and the upper skirt 22 is connected to the connecting ring 5G via the annular plate 43. To facilitate the joining work between the annular plate 43, the outer vessel upper shell 42, and the upper skirt 22, it is desirable that the upper surface of the annular plate 43 be a substantially horizontal plane.

[0034] In the above-mentioned connecting ring 5G, the second outer vessel joint 63 is arranged on the upper part of the base 50, but a second skirt joint 62 to which the upper skirt 22 is joined may be arranged instead of the second outer vessel joint 63. For example, as shown in Figure 10, when the second skirt joint 62 is arranged on the upper part of the base 50 of the connecting ring 5G, the lower end 221 of the upper skirt 22 may be joined to this second skirt joint 62, and the annular plate 43 of the outer vessel 4 may be joined to the upper skirt 22.

[0035] [Summary] The multi-shell tank 1 according to the first aspect of the present disclosure comprises: Inner tank 3, an outer tank 4 surrounding the inner tank 3; a cylindrical support skirt 2 extending vertically from the outer wall of the inner tank 3 to the foundation 10; A connecting ring 5 that forms a part of the support skirt 2 and the outer tank 4, The support skirt 2 has a first skirt member and a second skirt member connected by a connecting ring 5, and the outer tank 4 has a first outer tank member and a second outer tank member connected by a connecting ring 5. When the multi-shell tank 1 relating to the first item is applied to the above embodiment, the first skirt member is the lower skirt 21, the second skirt member is the upper skirt 22, the first outer tank member is the outer tank lower shell 41, and the second outer tank member is the outer tank upper shell 42 or the annular plate 43.

[0036] In the multi-shell tank 1 having the above configuration, the connecting ring 5 can separate the first and second outer tank members of the outer tank 4 to a degree that avoids the narrow space at the connection between the outer tank 4 and the supporting skirt 2. Furthermore, in the multi-shell tank 1 having the above configuration, the connecting ring 5 can separate the first and second skirt members of the supporting skirt 2 to a degree that avoids the narrow space at the connection between the outer tank 4 and the supporting skirt 2. This can alleviate the concentration of joining points at the connection between the supporting skirt 2 and the outer tank 4 on site. As a result, the joining work between the outer tank 4 and the supporting skirt 2 can be performed while avoiding the narrow space at the connection between the outer tank 4 and the supporting skirt 2, ensuring sufficient space for the joining work. For the same reason, sufficient space can be ensured for non-destructive testing of the joining points.

[0037] The multi-shell tank 1 according to the second item of the present disclosure is the multi-shell tank 1 according to the first item, wherein the connecting ring 5 has a first skirt joint 61 to which the first skirt member is joined, a second skirt joint 62 to which the second skirt member is joined, a first outer tank joint 64 to which the first outer tank member is joined, and a second outer tank joint 63 to which the second outer tank member is joined. When the multi-shell tank 1 relating to the second item is applied to the above embodiment, the first skirt member is the lower skirt 21, the second skirt member is the upper skirt 22, the first outer tank member is the outer tank lower shell 41, and the second outer tank member is the outer tank upper shell 42 or the annular plate 43.

[0038] The multi-shell tank 1 according to the third item of the present disclosure is the multi-shell tank 1 according to the second item, wherein the connecting ring 5 is under It has a first skirt joint 61 at the end. aboveIt has a cylindrical base 50 with a second skirt joint 62 at its end, an inner ring 54 or inner cylinder 56 with a first outer tank joint 64 at its tip that protrudes inward from the base 50, and an outer ring 53 with a second outer tank joint 63 at its tip that protrudes outward from the base 50.

[0039] In this way, the connection ring 5 can be realized relatively simply.

[0040] A multi-shell tank 1 according to a fourth aspect of the present disclosure is the multi-shell tank 1 according to the third aspect, wherein the outer ring portion 53 of the connection ring 5 has a horizontal surface.

[0041] Since the outer ring portion 53 has a horizontal surface, the horizontal surface of the outer ring portion 53 can be used as a foothold for joining the second outer tank member, thereby stabilizing the joining operation of the outer tank 4 and the support skirt 2.

[0042] The multi-shell tank 1 according to the fifth item of the present disclosure is the multi-shell tank 1 according to the first item, wherein the connecting ring 5 has a first skirt joint 61 to which the first skirt member is joined, a first outer tank joint 64 to which the first outer tank member is joined, and a second outer tank joint 63 to which the second outer tank member is joined, and the second skirt member is joined to the second outer tank member. When the multi-shell tank 1 relating to the fifth item is applied to the above embodiment, the first skirt member is the lower skirt 21, the second skirt member is the upper skirt 22, the first outer tank member is the outer tank lower shell 41, and the second outer tank member is the annular plate 43.

[0043] Furthermore, the multi-shell tank 1 relating to the sixth item of the present disclosure is the multi-shell tank 1 relating to the first item, wherein the connecting ring 5 has a first skirt joint 61 to which the first skirt member is joined, a first outer tank joint 64 to which the first outer tank member is joined, and a second skirt joint 62 to which the second skirt member is joined, and the second outer tank member is joined to the second skirt member. When the multi-shell tank 1 relating to the sixth item is applied to the above embodiment, the first skirt member is the lower skirt 21, the second skirt member is the upper skirt 22, the first outer tank member is the outer tank lower shell 41, and the second outer tank member is the annular plate 43.

[0044] The multi-shell tank 1 according to the seventh item of the present disclosure is a multi-shell tank 1 according to any one of the second to sixth items, in which the vertical positions of the first skirt joint 61 and the first outer tank joint 64 in the connecting ring 5 are different.

[0045] In this way, by separating the first skirt joint 61 and the first outer tub joint 64 in the vertical direction, a larger space can be secured for the joining operation of the support skirt 2 and the outer tub 4.

[0046] The multi-shell tank 1 according to the eighth item of the present disclosure is a multi-shell tank 1 according to any one of the second to fourth items, in which the vertical positions of the second skirt joint 62 and the second outer tank joint 63 in the connecting ring 5 are different.

[0047] By having the second skirt joint 62 and the second outer tank joint 63 spaced apart in the vertical direction in this manner, more space can be secured for the joining operation between the second outer tank joint 63 and the outer tank upper shell 42, and for the joining operation between the second skirt joint 62 and the upper skirt 22.

[0048] The multi-shell tank 1 according to the ninth item of the present disclosure is the multi-shell tank 1 according to the fifth item, wherein the connecting ring 5 has a first skirt joint 61 located at the lower end, a second outer tank joint 63 located at the upper end, and a first outer tank joint 64 located on the inner circumferential side of the first skirt joint 61, and the outer tank 4 has a first outer tank member, a second outer tank member, and a third outer tank member, the second outer tank member being an annular plate 43, and the second skirt member and the third outer tank member being joined to the upper surface of the annular plate 43.

[0049] In such a connecting ring 5, the thickness of the base 50 of the connecting ring 5 can be reduced, making it easier to manufacture the arc blocks that are components of the connecting ring 5. Furthermore, since the second skirt member and the third outer tank member are joined onto the annular plate 43, the annular plate 43 can be used as a work foothold when connecting the second skirt member and the third outer tank member to the annular plate 43, thereby improving the stability of the work.

[0050] The multi-shell tank 1 according to the tenth item of the present disclosure is the multi-shell tank 1 according to the second item, wherein the vertical cross section of the connecting ring 5 is rectangular with the outer upper corner and the inner lower corner chamfered, the second skirt joint 62 is located at the top of the rectangle, the first skirt joint 61 is located at the bottom of the rectangle, the second outer tank joint 63 is located at the corner face of the chamfered outer upper corner of the rectangle, and the first outer tank joint 64 is located at the corner face of the chamfered inner lower corner of the rectangle.

[0051] In this way, the connection ring 5 can be realized in a very simple manner.

[0052] The foregoing discussion of the present disclosure has been presented for purposes of illustration and description and is not intended to limit the present disclosure to the form disclosed herein. For example, in the foregoing detailed description, various features of the present disclosure are grouped together in a single embodiment for the purpose of streamlining the disclosure, but some of the features may also be combined. Furthermore, the features included in the present disclosure may also be combined into alternative embodiments, configurations, or aspects other than those discussed above.

Claims

1. An inner tank, an outer tank surrounding the inner tank; a cylindrical support skirt extending in the vertical direction from the outer wall of the inner tank to the foundation; a connecting ring that forms a part of the support skirt and the outer tank; the support skirt has a first skirt member and a second skirt member separated by the connecting ring, and the outer tank has a first outer tank member and a second outer tank member separated by the connecting ring; The connecting ring includes a cylindrical base portion having a first skirt joint at its lower end to which the first skirt member is joined and a second skirt joint at its upper end to which the second skirt member is joined, an inner ring portion or inner cylindrical portion having a first outer tank joint at its tip to which the first outer tank member is joined and protruding inward from the base, and an outer ring portion having a second outer tank joint at its tip to which the second outer tank member is joined and protruding outward from the base. Multi-shell tank.

2. the outer annular portion of the connecting ring has a horizontal surface; 2. The multi-shell tank of claim 1.

3. An inner tank; an outer tank surrounding the inner tank; a cylindrical support skirt extending in the vertical direction from the outer wall of the inner tank to the foundation; a connecting ring that forms a part of the support skirt and the outer tank; the support skirt has a first skirt member and a second skirt member separated by the connecting ring, and the outer tank has a first outer tank member and a second outer tank member separated by the connecting ring; The connecting ring has a first skirt joint portion to which the first skirt member is joined, a first outer tank joint portion to which the first outer tank member is joined, and a second outer tank joint portion to which the second outer tank member is joined, and the second skirt member is joined to the second outer tank member. Multi-shell tank.

4. An inner tank; an outer tank surrounding the inner tank; a cylindrical support skirt extending in the vertical direction from the outer wall of the inner tank to the foundation; a connecting ring that forms a part of the support skirt and the outer tank; the support skirt has a first skirt member and a second skirt member separated by the connecting ring, and the outer tank has a first outer tank member and a second outer tank member separated by the connecting ring; The connecting ring has a first skirt joint portion to which the first skirt member is joined, a first outer tank joint portion to which the first outer tank member is joined, and a second skirt joint portion to which the second skirt member is joined, and the second outer tank member is joined to the second skirt member. Multi-shell tank.

5. In the connecting ring, the first skirt joint portion and the first outer tank joint portion are positioned differently in the up-down direction.

5. A multi-shell tank according to any one of claims 1 to 4.

6. In the connecting ring, the second skirt joint portion and the second outer tank joint portion are positioned differently in the up-down direction.

3. The multi-shell tank according to claim 1 or 2.

7. the connecting ring has the first skirt joint portion disposed at a lower end, the second outer tank joint portion disposed at an upper end, and the first outer tank joint portion disposed on the inner peripheral side of the first skirt joint portion, The outer tank has the first outer tank member, the second outer tank member, and a third outer tank member, the second outer tank member being an annular plate, and the second skirt member and the third outer tank member being joined to an upper surface of the annular plate.

4. The multi-shell tank according to claim 3.

8. An inner tank; an outer tank surrounding the inner tank; a cylindrical support skirt extending in the vertical direction from the outer wall of the inner tank to the foundation; a connecting ring that forms a part of the support skirt and the outer tank; the support skirt has a first skirt member and a second skirt member separated by the connecting ring, and the outer tank has a first outer tank member and a second outer tank member separated by the connecting ring; The vertical cross section of the connecting ring is a rectangle with chamfered outer upper corners and inner lower corners, and includes a second skirt joining portion disposed at the upper part of the rectangle to which the second skirt member is joined, a first skirt joining portion disposed at the lower part of the rectangle to which the first skirt member is joined, a second outer tank joining portion disposed at the chamfered corner surface of the outer upper corner of the rectangle to which the second outer tank member is joined, and a first outer tank joining portion disposed at the chamfered corner surface of the inner lower corner of the rectangle to which the first outer tank member is joined. Multi-shell tank.

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