Cryogenic container

Abstract

To protect an exterior of a stationary tank or an exterior of a movable semitrailer from overpressure in a space between walls.SOLUTION: A cryogenic container 1 comprises an inner wall 2 defining a storage volume, and an outer wall 3 having a space 4 between vacuum insulation walls, and disposed around the inner wall. A pressure-control valve 5 configured so as to discharge excessive pressure in the space between the walls is disposed on the outer wall. The pressure-control valve can move between a first position and a second position thereof, and is guided in a vertical direction via a guide system located inside an opening. A cap is configured to be moved toward the second position by overpressure greater than a threshold determined in the space between the walls, and to be returned toward the first position by gravity when the overpressure greater than the determined threshold is stopped.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to cryogenic containers, and more particularly to tanks for storing cryogenic fluids.

[0002] More specifically, the present invention is a cryogenic container, particularly a tank for storing cryogenic fluids, comprising an inner wall defining a storage volume and an outer wall disposed around the inner wall with a vacuum insulation wall space therebetween, and the outer wall is provided with an overpressure valve configured to discharge excess pressure in the wall space, and the overpressure valve is provided with a cap attached so as to be movable between a first position closing the opening communicating with the wall space and a second position opening the opening. The present invention relates to a cryogenic container.

[0003] In particular, the present invention relates to an overpressure valve for any cryogenic container or cryogenic device (stationary or movable), and more particularly to an overpressure valve for a tank for storing a flammable cryogenic liquid (particularly hydrogen).

Background Art

[0004] The present invention particularly enables protection of the exterior (wall) of a stationary tank or the exterior (wall) of a movable semi-trailer from overpressure in the wall space (between the inner wall forming the inner tank and the wall forming the exterior).

[0005] Specifically, in the case of a fault or overpressure in the wall space, it is necessary to be able to discharge this overpressure and then avoid pumping ambient air when returning to a vacuum again.

[0006] In particular, in the case of leakage of a flammable liquid, it is important to avoid generating an explosive gas volume.

[0007] However, known overpressure valves (generally called "vacuum plugs") are generally difficult to handle, expensive and unsatisfactory. In particular, their automatic opening and closing mechanisms are large and / or not very reliable. [Overview of the project]

[0008] The object of the present invention is to overcome all or some of the above-mentioned drawbacks of the prior art.

[0009] For this purpose, otherwise according to the comprehensive definition given in the above preface, the container according to the present invention is characterized in that the cap is movable and guided vertically between a first position and a second position via a guide system located inside the opening, and the cap is configured to move toward the second position when an overpressure greater than a determined threshold in the interwall space is exceeded, and to return toward the first position by gravity when the overpressure greater than the aforementioned determined threshold is exceeded.

[0010] Furthermore, embodiments of the present invention may have one or more of the following features: - The cap and / or opening is provided with a sealing member such as a seal to ensure that the opening is tightly closed in its first position. - The sealing member is compressed between the wall defining the opening and the cap at its first position. - The guide system comprises a shaft fixed to the cap and a guide for the shaft fixedly mounted within the opening. - The shaft guide comprises a tubular section that slides to receive the shaft, and the aforementioned shaft guide is held within the opening via a pair of support arms fastened to a wall defining the opening. - The shaft guides the shaft along a vertical length equal to at least twice the transverse dimension of the shaft. - The shaft includes a transverse blocking member that forms a stop portion that limits the vertical position of the bottom of the shaft. - The cap and / or guide system is equipped with a flyweight to bias the cap toward a first position by gravity. - The fly weight is fixed to the shaft. - The flyweight is located at the lower end of the shaft and forms a stopper that limits the vertical position of the cap's top. - The opening is defined by a tubular wall section connected to the outer wall. - The tubular wall section is vertical and connected to the side (flank) of the outer wall via a bend. - The end of the vertical tubular wall section is located at the same height as or below the upper end of the outer wall. - The device is a cryogenic fluid storage tank, and its inner wall defines the storage volume for the fluid. - The device is a cold box for cryogenic equipment that houses cryogenic components.

[0011] The present invention may also relate to any alternative apparatus or method comprising any combination of the above or below features of the claims.

[0012] Other specific features and advantages will become apparent by reading the following description, which is given with reference to the drawings. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 shows schematic and partial views of a vertical and longitudinal cross-section illustrating an example of a container that implements the present invention. [Figure 2] Figure 2 shows a schematic and partial view of the details of the overpressure valve of the vessel in Figure 1 in a vertical cross-section. [Figure 3] Figure 3 shows a schematic, partial, and transparent perspective view of the valve details. [Figure 4] Figure 4 shows a schematic and partial perspective view of a half-section of the overpressure valve mentioned above. [Modes for carrying out the invention]

[0014] Figure 1 shows a cryogenic container composed of a cryogenic fluid storage tank. This tank includes an inner wall or interior 2, for example, having a generally cylindrical shape that defines a storage volume for the fluid, and an outer wall 3 disposed with a vacuum insulation wall space 4 around the inner wall 2.

[0015] The tank conventionally includes a valve / a circuit provided with a plurality of valves, which is not described in detail for the sake of brevity.

[0016] The outer wall 3 has an opening 7 that is closed by an overpressure valve 5 configured to discharge excessive pressure in the wall space 4 in case of a malfunction. The opening 7 is defined, for example, by a tubular wall portion 13 connected to the outer wall 3.

[0017] As illustrated, the overpressure valve 5 can be formed at the end of the tubular wall portion 13, which is vertical in the usage configuration and is connected, for example, via a bend, to the side surface of the outer wall 3.

[0018] The overpressure valve 5 includes, for example, a disc-shaped cap 6, which is attached so as to be movable relative to a circular opening 7 communicating with the wall space 4.

[0019] The cap 6 is movable between a first position closing the opening 7 and a second position opening the opening 7.

[0020] More precisely, the cap 6 is attached and vertically guided via guide systems 9, 10 located inside the opening 7 (or the tubular portion 13) so as to be movable between its first and second positions.

[0021] The cap 6 is configured to be freely moved towards the second position by an overpressure greater than a determined threshold value in the wall space 4. That is, when the pressure in the wall space exceeds the determined threshold value, this pressure lifts the cap to open the opening 7.

[0022] Similarly, once this overpressure subsides, cap 6 automatically returns to its first position due to gravity.

[0023] A sealing member 8, such as an O-ring seal, may be provided on the edge of the opening 7 to ensure that the opening 7 is tightly closed. Thus, the seal 8 is compressed when the cap 6 is in its first position, creating a closure under vacuum.

[0024] In the illustrated example, the guide system comprises a shaft 10 fixed to the cap 6 and a guide 9 for the shaft 10 mounted within the opening 7. The guide 9 is preferably fixed to the opening. For example, the upper end of the shaft 10 is screwed into the cap 6.

[0025] The shaft guide 9 may have a tubular section that receives the shaft 10 in a vertical sliding manner. The guide 9 is held within the opening 7 (preferably centered in the tubular section 13) via, for example, a pair of support arms 11 fastened to a wall defining the opening 7. In the example illustrated in Figure 3, for example, three support arms 11 are provided around the guide, distributed at 120-degree angles. One end of each arm may be welded to the guide 9, and the other end of each arm may be welded to the inner wall of the tubular section 13.

[0026] The shaft 10 is, for example, cylindrical in shape with a disc-shaped cross-section. The guide 9 is preferably sized to guide the shaft 10 along a vertical length equal to at least twice the transverse dimension (diameter) of the shaft 10.

[0027] Preferably, a flyweight 12 is provided to contribute to closing the cap 6. Preferably, the flyweight 12 is located at the height of the second lower end of the shaft 10. The flyweight 12 and / or the shaft may form projections that abut against the guide 9 (or similar) to limit the top position of the cap 6 and prevent it from detaching from the orifice and the container.

[0028] As illustrated in Figure 4, the shaft 10 may include a transverse blocking member 14 that forms a stopper limiting the vertical position of the bottom of the shaft 10. This blocking member 14, which may include a (preferably elastic) pin mounted through the shaft 10, prevents the shaft 10 from falling into the inter-wall space 4 if the cap 6 comes off. Any other transverse blocking member is conceivable.

[0029] Therefore, the guide, return, and mounting mechanisms for cover 6 can be fully integrated within the orifice 7.

[0030] As illustrated in Figure 1, in particular, in the case of a movable cryogenic horizontal tank (semi-trailer or similar), the end of the vertical tubular wall section 13 is located at the same height as or below the upper end of the outer wall 3.

[0031] Naturally, the present invention can also be applied to other containers, particularly cold boxes in cryogenic (e.g., liquefaction) facilities.

Claims

1. A cryogenic vessel (1), in particular a tank for storing a cryogenic fluid, comprising an inner wall (2) defining a storage volume and an outer wall (3) arranged around the inner wall (2) with a vacuum insulating inter-wall space (4), the outer wall (3) is provided with an overpressure valve (5) configured to vent excess pressure in the inter-wall space (4); the overpressure valve (5) comprises a cap (6) attached to an opening (7) communicating with the inter-wall space (4) so ​​as to be movable between a first position for closing the opening (7) and a second position for opening the opening (7); said cap (6) being movable and vertically guided between its first and second positions via a guide system (9, 10) located inside said opening (7); The cryogenic container (1), wherein the cap (6) is configured to be moved towards the second position by an overpressure in the inter-wall space (4) greater than a determined threshold and to move back towards the first position by gravity when the overpressure greater than the determined threshold ceases, 1. A cryocontainer, characterized in that the guide system (9, 10) comprises a shaft (10) fixed to the cap (6) and a guide (9) for the shaft (10) mounted in the opening (7).

2. 2. The cryocontainer according to claim 1, characterized in that the cap (6) and / or the opening (7) are provided with a sealing member (8), such as a seal, ensuring that the opening (7) is tightly closed in its first position.

3. 3. The cryocontainer according to claim 2, characterized in that the sealing member (8) is compressed between the wall defining the opening and the cap (6) in its first position.

4. 4. The cryogenic container according to claim 1, wherein the guide (9) of the shaft (10) comprises a tubular portion that slidingly receives the shaft (10), and the guide (9) of the shaft (10) is held in the opening (7) via a set of support arms (11) fastened to a wall that defines the opening.

5. 4. The cryogenic container according to claim 1, wherein the guide (9) of the shaft (10) guides the shaft (10) along a vertical length at least equal to twice the transverse dimension of the shaft (10).

6. Cryogenic vessel according to any one of claims 1 to 3, characterized in that the shaft (10) is provided with a transverse blocking member (14) forming a stop limiting the bottom vertical position of the shaft (10).

7. 4. The cryocontainer according to any one of claims 1 to 3, characterized in that the cap (6) and / or the guide system (9, 10) comprise a flyweight (12) for biasing the cap (6) towards the first position by gravity.

8. 8. The cryocontainer according to claim 7, characterized in that the flyweight (12) is fixed to the shaft (10).

9. 9. The cryocontainer according to claim 8, characterized in that the flyweight (12) is located at the lower end of the shaft (10) and forms a stop limiting the top vertical position of the cap (6).

10. Cryocontainer according to any one of claims 1 to 3, characterized in that the opening (7) is defined by a tubular wall section (13) connected to the outer wall (3).

11. Cryocontainer according to any one of claims 1 to 3, characterized in that the tubular wall portion (13) is vertical and is connected to a side of the outer wall (3) via a bend.

12. 12. Cryocontainer according to claim 11, characterized in that the end of the vertical tubular wall portion (13) is located at the same height as or below the upper end of the outer wall (3).

13. The cryocontainer according to any one of claims 1 to 3, characterized in that the cryocontainer (1) is a tank for storing a cryogenic fluid, the inner wall (2) defining a storage volume for the cryogenic fluid.

14. Cryocontainer (1) according to any one of claims 1 to 3, characterised in that the cryocontainer is a cold box of a cryogenic installation housing cryogenic components.

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