Content inlet / outlet structure of double-shell container and manufacturing method of double-shell container

Abstract

To provide a content entrance / exit structure for a double-shell container that is superior in durability by enhancing soundness of welding of a content taking-out part to the double-shell container.SOLUTION: A content entrance / exit structure for a double-shell container 10 including an inner container 12 and an outer container 20, includes an entrance / exit member 30 fitted to the double-shell container 10 to be fitted to a first opening 15 formed on the inner container 12 and a second opening 25 formed on the outer container 20, wherein the entrance / exit member 30 has a cylindrical body part 34 which defines a content entrance / exit 32 where contents can be circulated, an inner flange part 36 which includes an outer peripheral edge extending outward from the body part 34 and butt-welded to an inner peripheral edge of the first opening 15 of the inner container 12, and an outer flange part 38 which includes an outer peripheral edge extending outward from the body part 34 and butt-welded to an inner peripheral edge of the second opening 25 of the outer container 20.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an inlet / outlet structure for the contents of a double-shell container and a method for manufacturing a double-shell container.

Background Art

[0002] As a container used as a culture tank or the like, there is known a so-called double-shell container having an inner container and an outer container, and defining a temperature control medium passage through which a temperature control medium flows between the inner container and the outer container (for example, Patent Document 1).

[0003] In such a double-shell container, the contents outlet structure for putting in and taking out the contents into and from the inner container includes a cylindrical member having one end welded to the outer peripheral edge of an opening formed in the outer container and the other end welded to the outer surface of the inner container, and an inlet / outlet pipe including one end attached to the inner container by welding inside the cylindrical member (the opening portion). The internal passage of the inlet / outlet pipe communicates with the contents inlet / outlet hole formed in the inner container. The cylindrical member is provided to secure the space necessary for an operator to weld one end of the inlet / outlet pipe to the outer surface of the inner container, and has an inner diameter sufficiently larger than the outer diameter of the inlet / outlet pipe.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the welded portion of the cylindrical member to the outer surface of the inner container extends across the inner container that is greatly affected by the heat of the contents and the cylindrical member that is greatly affected by the heat of the temperature control medium having a different temperature from the contents, the welded portion is subject to thermal stress due to the difference in thermal expansion between the inner container and the cylindrical member. In particular, when batch operation is performed, the welded portion is repeatedly subjected to thermal stress and is exposed to severe conditions with respect to fatigue strength.

[0006] For this reason, the welding between the inner container and the cylindrical member is preferably performed by full penetration welding and non-destructive inspection is preferably carried out. However, since the welding is fillet welding rather than butt welding, it is difficult to achieve full penetration welding. In addition, it is difficult to secure a large space required for non-destructive inspection of the welded portion, and it is also difficult to confirm the soundness of the welding.

[0007] In view of the above background, an object of the present invention is to provide a content inlet / outlet structure for a double-shell container that enhances the soundness of the welding of the content inlet / outlet portion to the double-shell container and has excellent durability.

Means for Solving the Problems

[0008] A content inlet / outlet structure of a double-shell container according to an embodiment of the present invention is a content inlet / outlet structure of a double-shell container (10) having an inner container (12) and an outer container (20), and has an inlet / outlet member (30) attached to the double-shell container so as to fit into a first opening (15) formed in the inner container and a second opening (23) formed in the outer container. The inlet / outlet member has a cylindrical main body portion (34) that defines a content inlet / outlet (32) through which the content can flow, an inner flange portion (36) that extends outward from the main body portion and includes an outer peripheral edge butt-welded to the inner peripheral edge of the first opening of the inner container, and an outer flange portion (38) that extends outward from the main body portion and includes an outer peripheral edge butt-welded to the inner peripheral edge of the second opening of the outer container.

[0009] According to this configuration, the soundness of the welding of the content inlet / outlet portion to the double-shell container is improved, and excellent durability is obtained.

[0010] In the content inlet / outlet structure of the double-shell container, preferably, the main body portion has an annular cross-sectional shape, and the outer diameter decreases toward the central portion in the axial direction, and the outer peripheral surface extending between the inner flange portion and the outer flange portion is a curved surface (44) that is concave when viewed in the longitudinal section.

[0011] According to this configuration, stress concentration at the boundary between the inner flange portion, the outer flange portion, and the main body portion is suppressed, and the mechanical strength of the inner flange portion and the outer flange portion is also improved.

[0012] In the content inlet / outlet structure of the double-shell container, preferably, the curved surface has a constant curvature throughout, and both ends are connected to the outer peripheral edge of the inner flange portion and the outer peripheral edge of the outer flange portion.

[0013] According to this configuration, stress concentration at the boundary between the inner flange portion, the outer flange portion, and the main body portion is suppressed, and the mechanical strength of the inner flange portion and the outer flange portion is also improved.

[0014] In the content inlet / outlet structure of the double-shell container, preferably, the outer flange portion includes an annular member (46) butt-welded to the outer periphery of the main body portion.

[0015] According to this configuration, the degree of freedom in the design of the outer flange portion is improved.

[0016] In the content inlet / outlet structure of the double-shell container, preferably, the double-shell container defines a temperature control medium passage (28) through which a temperature control medium flows between the inner container and the outer container.

[0017] According to this configuration, the temperature inside the inner container is controlled by the temperature control medium.

[0018] In the content inlet / outlet structure of the double-shell container, preferably, the content inlet / outlet includes a tapered portion (32A) whose diameter is enlarged toward the inside of the inner container.

[0019] According to this configuration, even if the passage length of the content inlet / outlet becomes long, it becomes difficult for the content to accumulate in the content inlet / outlet.

[0020] In the content inlet / outlet structure of the double-shell container, preferably, the outer container is formed by joining a plurality of divided bodies (22A, 22B) to each other.

[0021] According to this configuration, the assembly of the outer container to the inner container can be performed without interfering with the inlet / outlet member attached to the inner container.

[0022] A method for manufacturing a double-shell container according to an embodiment of the present invention is a method for manufacturing a double-shell container having an inner container and an outer container and having the content inlet / outlet structure according to the above-described embodiment, the method including: a first step of butt-welding the outer peripheral edge of the inner flange portion of the inlet / outlet member to the inner peripheral edge of the first opening of the inner container; a second step of attaching the outer container to the outside of the inner container after the first step; and a third step of butt-welding the outer peripheral edge of the outer flange portion of the inlet / outlet member to the inner peripheral edge of the second opening of the outer container after the second step.

[0023] According to this manufacturing method, the butt-welding of the inner flange portion of the inlet / outlet member to the inner container and the butt-welding of the outer flange portion of the inlet / outlet member to the outer container can be performed from the outside of the container.

[0024] In the method for manufacturing the double-shell container, preferably, the inner flange portion and the outer flange portion are in an annular shape, and the outer diameter of the inner flange portion is larger than the outer diameter of the outer flange portion.

[0025] According to this manufacturing method, the welding of the inner flange portion to the inner container can be performed without interfering with the outer flange portion.

[0026] Another manufacturing method of the double-shell container according to an embodiment of the present invention is a manufacturing method of a double-shell container having an inner container and an outer container and provided with the content inlet / outlet structure according to the above-described embodiment, including: a first step of butt-welding the outer peripheral edge of the outer flange portion of the inlet / outlet member to the inner peripheral edge of the second opening of the outer container; a second step of attaching the outer container to the outside of the inner container after the first step; and a third step of butt-welding the outer peripheral edge of the inner flange portion of the inlet / outlet member to the inner peripheral edge of the first opening of the inner container after the second step.

[0027] According to this manufacturing method, the butt-welding between the inner flange portion of the inlet / outlet member and the inner container and the butt-welding between the outer flange portion of the inlet / outlet member and the outer container can be performed from the inside of the container.

[0028] In the manufacturing method of the double-shell container, preferably, the inner flange portion and the outer flange portion are in an annular shape, and the outer diameter of the outer flange portion is larger than the outer diameter of the inner flange portion.

[0029] According to this manufacturing method, the welding of the outer flange portion to the outer container can be performed without interference with the inner flange portion.

Advantages of the Invention

[0030] According to the content inlet / outlet structure of the double-shell container according to the present invention, the soundness of the welding of the content inlet / outlet portion to the double-shell container is improved, and excellent durability can be obtained.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0032] Hereinafter, with reference to the drawings, embodiments of the content inlet / outlet structure of the double-shell container according to the present invention will be described.

[0033] As shown in FIGS. 1 to 3, the double-shell container 10 has a metal inner container 12 and a metal outer container 20 disposed outside the inner container 12.

[0034] The inner container 12 has a sealed structure including a cylindrical portion 14, a dome-shaped upper end body 16 joined to the upper part of the cylindrical portion 14, and a dome-shaped lower end body (end plate) 18 joined to the lower part of the cylindrical portion 14, and accommodates substances having fluidity such as liquids and powders, that is, contents, inside. At least one of the upper end body 16 and the lower end body 18 is provided with a content inlet / outlet portion (not shown) for the entry and exit of the contents into and from the inner container 12.

[0035] The outer container 20 includes a cylindrical portion 22 formed by welding the side edges of two arc-shaped front and rear split bodies 22A and 22B (see FIG. 2) having a 180-degree rotation angle in cross-sectional shape to each other by a butt welding portion W1, an annular upper end body 24 joined to the upper end of the cylindrical portion 22 and the outer peripheral surface of the cylindrical portion 14 of the inner container 12, and an annular lower end body 26 joined to the lower end of the cylindrical portion 22 and the outer peripheral surface of the cylindrical portion 14 of the inner container 12. The butt welding portion W1 of the split bodies 22A and 22B may be performed by TIG welding or MIG welding.

[0036] Since the inner diameter of the cylindrical portion 22 is larger than the outer diameter of the cylindrical portion 14, a temperature control medium passage 28 having an annular cross-sectional shape closed by the upper end body 24 and the lower end body 26 in the vertical direction is defined between the cylindrical portion 14 and the cylindrical portion 22. A temperature control medium inlet (not shown) for the temperature control medium passage 28 is provided at the upper end of the upper end body 24 or the cylindrical portion 22, and a temperature control medium outlet (not shown) for the temperature control medium passage 28 is provided at the lower end of the lower end body 26 or the cylindrical portion 22. A temperature control medium such as cooling water flows through the temperature control medium passage 28. Thereby, the temperature of the inner container 12 is controlled by the temperature control medium.

[0037] A metal inlet / outlet member (nozzle member) 30 is attached to the side portion of the double-shell container 10. As shown in FIG. 4, the inlet / outlet member 30 has a cylindrical main body portion 34 that defines a content inlet / outlet (passage) 32 through which the content inside the inner container 12 can flow, an annular inner flange portion 36 that extends outward from the inner end of the main body portion 34, and an annular outer flange portion 38 that extends outward from the outer end of the main body portion 34. The content inlet / outlet 32 includes a tapered portion 32A whose diameter expands toward the inside of the inner container 12. The tapered portion 32A is preferably provided over as long a length as possible of the content inlet / outlet 32.

[0038] The connecting portion (corner portion) between the outer peripheral surface of the main body portion 34 and the upper surface of the inner flange portion 36 is formed by a large-radius surface 37. The connecting portion (corner portion) between the outer peripheral surface of the main body portion 34 and the lower surface of the outer flange portion 38 is formed by a large-radius surface 39. Thereby, stress concentration at the connecting portion between the outer peripheral surface of the main body portion 34 and the upper surface of the inner flange portion 36 and at the connecting portion between the outer peripheral surface of the main body portion 34 and the lower surface of the outer flange portion 38 is alleviated.

[0039] The inlet / outlet member 30 is for taking in and out the content (accommodated substance) into and from the inner container 12, and a passage connecting member 42 is attached to the outer end face by a plurality of bolts 40.

[0040] The inner flange portion 36 has an outer diameter larger than that of the outer flange portion 38, fits into the first opening 15 formed in the cylindrical portion 14, and includes an outer peripheral edge 36A butt-welded to the inner peripheral edge of the first opening 15 by TIG welding or MIG welding. The butt-welded portion between the inner flange portion 36 and the cylindrical portion 14 is indicated by the reference sign W2.

[0041] The outer flange portion 38 fits into the second opening 23 formed coaxially with the first opening 15 in the cylindrical portion 22, and includes an outer peripheral edge 38A butt-welded to the inner peripheral edge of the second opening 23 by TIG welding or MIG welding. The butt-welded portion between the outer flange portion 38 and the cylindrical portion 14 is indicated by the reference sign W3.

[0042] Since the inlet / outlet member 30 is welded to the inner container 12 by the butt-welded portion W2 of the inner flange portion 36 and welded to the outer container 20 by the butt-welded portion W3 of the outer flange portion 38, the soundness of the welding of the inlet / outlet member 30 to the inner container 12 and the outer container 20 is sufficiently ensured under full penetration welding as compared with the case including fillet welding.

[0043] Thereby, even if the butt-welded portions W2 and W3 are repeatedly subjected to thermal stress due to the temperature difference between the contents of the inner container 12 and the temperature control medium in the temperature control medium passage 28, that is, the difference between the temperature inside and outside the inner container 12, cracking in the butt-welded portions W2 and W3 and in the vicinity of the welded portions is suppressed, and excellent durability is obtained.

[0044] Since the inlet / outlet member 30 is welded to the inner container 12 at the inner flange portion 36 and welded to the outer container 20 at the outer flange portion 38, it is fixed to the double-shell container 10 in a double-cantilever state. Thus, the mounting strength of the inlet / outlet member 30 to the double-shell container 10 is improved, and excellent durability is obtained.

[0045] Since the content inlet / outlet 32 includes a tapered portion 32A whose diameter expands toward the inside of the inner container 12, even if the passage length of the content inlet / outlet 32 becomes long, it is difficult for the content to accumulate in the content inlet / outlet 32. The tapered portion 32A is preferably provided over the entire length of the content inlet / outlet 32 as much as possible so that this effect can be obtained well.

[0046] Next, one embodiment of a method for manufacturing the double-shell container 10 having the content inlet / outlet structure with the above-described configuration will be described with reference to FIG. 5.

[0047] First, as shown in FIG. 5(A), as a first step, the inner flange portion 36 of the inlet / outlet member 30 is fitted to the first opening 15 of the inner container 12, and the outer peripheral edge 36A of the inner flange portion 36 is butt-welded to the inner peripheral edge of the first opening 15 by a welding torch 50 that performs TIG welding or MIG welding from the outside of the inner container 12. Thereby, a butt-welded portion W2 by complete penetration is formed.

[0048] Since the inner flange portion 36 has an outer diameter larger than that of the outer flange portion 38, the butt-welded portion W2 is located radially outward of the outer peripheral edge 38A of the outer flange portion 38. Thereby, when welding the butt-welded portion W2, the welding torch 50 does not interfere with the outer flange portion 38, and the welding of the butt-welded portion W2 can be appropriately performed with a spatial margin.

[0049] After completion of the first step, the butt-welded portion W2 can be visually observed from the outside of the inner container 12, and access can be made to the butt-welded portion W2 from the outside of the inner container 12. Therefore, visual inspection of the butt-welded portion W2 and non-destructive inspection by X-rays or the like can be easily performed. Since the butt-welded portion W2 is located radially outward of the outer peripheral edge 38A of the outer flange portion 38, visual inspection of the butt-welded portion W2 and non-destructive inspection by X-rays or the like can be surely performed without being obstructed by the outer flange portion 38 from the outside of the inner container 12.

[0050] After completion of the first step and inspection of the butt weld W2, as a second step, the split body 22A is arranged on the front side of the cylindrical portion 14 so that the outer flange portion 38 of the inlet / outlet member 30 fits into the second opening 23 formed in the front split body 22A. At the same time, as shown in FIG. 2, the rear split body 22B is arranged on the rear side of the cylindrical portion 14, and the side edges of the split bodies 22A and 22B are butt welded (butt weld W1) from the outside to complete the cylindrical portion 22.

[0051] Then, the upper end body 24 (see FIGS. 2 and 3) is joined to the outer peripheral surface of the cylindrical portion 14 of the inner container 12 and the upper end of the cylindrical portion 22 of the outer container 20 by welding or the like, and the lower end body 26 is joined to the outer peripheral surface of the cylindrical portion 14 of the inner container 12 and the lower end of the cylindrical portion 22 of the outer container 20 by welding or the like. Thereby, the outer container 20 is fixed to the inner container 12 and the temperature control medium passage 28 is defined.

[0052] After the second step, as shown in FIG. 5(B), as a third step, the outer flange portion 38 is fitted into the second opening 23 of the outer container 20, and the outer peripheral edge 38A of the outer flange portion 38 is butt welded by a welding torch 50 that performs TIG welding or MIG welding from the outside of the outer container 20 to the inner peripheral edge of the second opening 23. Thereby, a butt weld W3 with complete penetration is formed.

[0053] Thereby, the attachment of the inlet / outlet member 30 to the inner container 12 and the outer container 20 is completed.

[0054] Since the butt weld W3 is exposed toward the outside of the outer container 20, visual inspection of the butt weld W3 and non-destructive inspection by X-rays or the like can be easily performed from the outside of the outer container 20.

[0055] The welding of the butt welds W2 and W3 is performed by TIG welding or MIG welding and is performed in an inert gas atmosphere, so that oxidation and mixing of impurities in the butt welds W2 and W3 and the periphery of the weld are suppressed, and the soundness of the welding is improved.

[0056] The butt-welded part W2 may be performed from the inside of the inner container 12.

[0057] Next, another embodiment of the content inlet / outlet structure of the double-shell container 10 will be described with reference to FIG. 7. In FIG. 7, the parts corresponding to those in FIG. 4 are denoted by the same reference numerals as those in FIG. 4, and the description thereof will be omitted.

[0058] In this embodiment, the main body portion 34 of the inlet / outlet member 30 has an annular cross-sectional shape, and the outer diameter gradually decreases toward the central portion in the axial direction. The outer peripheral surface extending between the inner flange portion 36 and the outer flange portion 38 is a curved surface 44 that is concave when viewed in the longitudinal section. The curved surface 44 has a constant curvature throughout, and both ends are smoothly connected to the outer peripheral edge 36A of the inner flange portion 36 and the outer peripheral edge 38A of the outer flange portion 38.

[0059] According to this shape, stress concentration at the boundary between the inner flange portion 36, the outer flange portion 38, and the main body portion 34 is suppressed, and the mechanical strength of the inner flange portion 36 and the outer flange portion 38 is also improved.

[0060] Thereby, the durability of the double-shell container 10 to which the inlet / outlet member 30 is attached is improved.

[0061] Next, another embodiment of the content inlet / outlet structure of the double-shell container 10 will be described with reference to FIG. 8. In FIG. 8, the parts corresponding to those in FIG. 4 are denoted by the same reference numerals as those in FIG. 4, and the description thereof will be omitted.

[0062] In this embodiment, an annular member 46 is fixed to the outer periphery of the outer end side of the main body portion 34 by a butt-welded part W4. The annular member 46 forms a part equivalent to the outer flange portion 38 in the above-described embodiment, and the cylindrical portion 22 of the outer container 20 is welded to the outer edge by a butt-welded part W3.

[0063] In this embodiment, since the outer flange portion 38 is constituted by an annular member 46 separate from the main body portion 34, the degree of freedom in the design of the outer flange portion 38 is improved, and the manufacture of the main body portion 34 becomes easier.

[0064] The butt welding portion W4 of the annular member 46 may be performed in a single state before the inlet / outlet member 30 is attached to the inner container 12. In this case, after the inlet / outlet member 30 is attached to the inner container 12, the annular member 46 may be fixed to the main body portion 34 by butt welding from the outside.

[0065] The rounded surface 39 of the connection portion between the outer peripheral surface of the main body portion 34 and the lower surface of the outer flange portion 38 may be formed by cutting the bead of the butt welding portion W4 in a state before the inlet / outlet member 30 is attached to the inner container 12.

[0066] Although the description of the specific embodiment is finished above, the present invention can be widely modified and implemented without being limited to the above embodiment.

[0067] For example, the inner flange portion 36 may also be constituted by an annular member separate from the main body portion 34 as in the embodiment shown in FIG. 8. The outer container 20 may be divided vertically or horizontally with the attachment portion of the inlet / outlet member 30 as a boundary. Although the outer container 20 has a divided structure from the viewpoint of assembly workability, it is not limited to the divided structure and may be constituted by a single cylindrical body. The inlet / outlet member 30 may be provided at the bottom of the double-shell container 10 as shown in FIG. 8.

[0068] The manufacture of the double-shell container 10 is not limited to the manufacturing method (process) of the above-described embodiment, and the double-shell container 10 can be manufactured by various manufacturing methods.

[0069] For example, the double-shell container 10 may be manufactured by a process including a first step of butt-welding the outer peripheral edge of the outer flange portion 38 of the inlet / outlet member 30 to the inner peripheral edge of the second opening 23 of the outer container 20, a second step of attaching the outer container 20 to the outside of the inner container 12 after the first step, and a third step of butt-welding the outer peripheral edge of the inner flange portion 36 of the inlet / outlet member 30 to the inner peripheral edge of the first opening 15 of the inner container 12 after the second step. Also in this manufacturing method, the welding of the inner flange portion 36 of the inlet / outlet member 30 to the inner container 12 and the welding of the outer flange portion 38 of the inlet / outlet member 30 to the outer container 20 can be performed soundly by butt-welding.

[0070] In this case, it is preferable that the outer diameter of the outer flange portion 38 is larger than the outer diameter of the inner flange portion 36 so that the welding of the outer flange portion 38 to the outer container 20 can be performed without interference with the inner flange portion 36.

[0071] The welding of each butt-welding portion W1 to W4 is not limited to TIG welding or MIG welding, and may be performed by a welding method suitable for the manufacturing method.

Explanation of Reference Numerals

[0072] 10: Double-shell container 12: Inner container 14: Cylindrical portion 15: First opening 16: Upper end body 18: Lower end body 20: Outer container 22: Cylindrical portion 22A: Divided body 22B: Divided body 23: Second opening 24: Upper end body 26: Lower end body 28: Temperature control medium passage 30: Inlet / outlet member 32: Content inlet / outlet 32A: Tapered portion 34: Body portion 36: Inner flange portion 36A: Outer peripheral edge 37: Rounded surface 38: Outer flange part 38A: Outer peripheral edge 39: Rounded surface 40: Bolt 42: Passage connection member 44: Curved surface 46: Annular member 50: Welding torch W1: Butt welding part W2: Butt welding part W3: Butt welding part W4: Butt welding part

Claims

1. A structure for an inlet / outlet of the contents of a double-shell container having an inner container and an outer container, comprising an inlet / outlet member attached to the double-shell container so as to fit into a first opening formed in the inner container and a second opening formed in the outer container, wherein the inlet / outlet member has a cylindrical main body portion defining an outlet for the contents through which the contents can flow, an inner flange portion extending outward from the main body portion and including an outer peripheral edge butt-welded to the inner peripheral edge of the first opening of the inner container, and an outer flange portion extending outward from the main body portion and including an outer peripheral edge butt-welded to the inner peripheral edge of the second opening of the outer container. A structure for an inlet / outlet of the contents of a double-shell container.

2. The structure for an inlet / outlet of the contents of a double-shell container according to claim 1, wherein the main body portion has an annular cross-sectional shape, the outer diameter decreases toward the central portion in the axial direction, and the outer peripheral surface extending between the inner flange portion and the outer flange portion is a curved surface that is concave when viewed in a longitudinal section.

3. The structure for an inlet / outlet of the contents of a double-shell container according to claim 2, wherein the curved surface has a constant curvature throughout and both ends are connected to the outer peripheral edge of the inner flange portion and the outer peripheral edge of the outer flange portion.

4. The structure for an inlet / outlet of the contents of a double-shell container according to any one of claims 1 to 3, wherein at least one of the inner flange portion and the outer flange portion includes an annular member butt-welded to the outer periphery of the main body portion.

5. The structure for an inlet / outlet of the contents of a double-shell container according to any one of claims 1 to 4, wherein the double-shell container defines a temperature control medium passage through which a temperature control medium flows between the inner container and the outer container.

6. The structure for an inlet / outlet of the contents of a double-shell container according to any one of claims 1 to 5, wherein the outlet for the contents includes a tapered portion having an enlarged diameter toward the inside of the inner container.

7. The structure for an inlet / outlet of the contents of a double-shell container according to any one of claims 1 to 6, wherein the outer container is formed by joining a plurality of divided bodies.

8. A method for manufacturing a double-shell container having an inner container and an outer container and provided with the structure for an inlet / outlet of the contents according to any one of claims 1 to 7, comprising a first step of butt-welding the outer peripheral edge of the inner flange portion of the inlet / outlet member to the inner peripheral edge of the first opening of the inner container, and a second step of attaching the outer container to the outside of the inner container after the first step. A method for manufacturing a double-shell container, comprising a third step of butt-welding the outer peripheral edge of the outer flange portion of the inlet / outlet member to the inner peripheral edge of the second opening of the outer container after the second step.

9. The method for manufacturing a double-shell container according to claim 8, wherein the inner flange portion and the outer flange portion are annular in shape, and the outer diameter of the inner flange portion is larger than the outer diameter of the outer flange portion.

10. A method for manufacturing a double-shell container having an inner container and an outer container and provided with the content inlet / outlet structure according to any one of claims 1 to 7, a first step of butt-welding the outer peripheral edge of the outer flange portion of the inlet / outlet member to the inner peripheral edge of the second opening of the outer container; a second step of attaching the inner container to the inside of the outer container after the first step; a third step of butt-welding the outer peripheral edge of the inner flange portion of the inlet / outlet member to the inner peripheral edge of the first opening of the inner container after the second step.

11. The method for manufacturing a double-shell container according to claim 10, wherein the inner flange portion and the outer flange portion are annular in shape, and the outer diameter of the outer flange portion is larger than the outer diameter of the inner flange portion.

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