Multilayer shell structure

Abstract

The multilayer shell structure includes: a first shell; a laminated heat insulation material surrounding the first shell; a second case that surrounds the laminated heat insulation material and has an exhaust port; and an exhaust port cover disposed at the exhaust port in an intermediate chamber between the first case and the second case, the exhaust port cover having: a cover body having a main surface facing the surface of the laminated heat insulator around the exhaust port cover; and a main body part that connects the lid and the exhaust port, the main body part having a communication port that communicates the intermediate chamber and the exhaust port and that has an opening axial direction substantially parallel to a main surface of the lid.

Description

Technical Field

[0001] The present disclosure relates to a multilayer shell structure having a vacuum insulation layer. Background Art

[0002] In the past, a multilayer shell tank was used as a container for storing extremely low-temperature liquefied gas. The multilayer shell tank has an inner tank for storing liquefied gas and an outer tank surrounding the inner tank, and there is a vacuum insulation layer that reduces the pressure between the inner and outer tanks to a state close to vacuum. Examples of such multilayer shell tanks include liquefied gas storage tanks installed on the ground, loading and unloading tanks or fuel tanks carried on ships, and liquefied gas transport tanks possessed by tank containers. Patent Document 1 discloses a multilayer shell tank as a liquefied gas transport tank.

[0003] The multilayer shell tank (transport container) described in Patent Document 1 has: an inner tank (inner container) that stores liquefied gas; a heat shield that surrounds the inner tank; a refrigerant tank that stores refrigerant supplied to the heat shield; and an outer tank (outer container) that surrounds the inner tank, the heat shield, and the refrigerant tank. The outer surface of the inner tank is covered with a laminated insulation (Multilayer Insulation: MLI) composed of multiple layers of foil-like elements. In addition, the intermediate chamber between the inner tank and the outer tank becomes a vacuum insulation layer that is decompressed to a state close to vacuum.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-515218 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the past, in order to make the inner and outer tanks of the multilayer shell tank vacuum, a vacuum pump was connected to the exhaust port arranged in the outer tank, and the vacuum pump was operated to forcibly exhaust the inner and outer tanks. However, in a structure where the outer surface of the inner tank is covered with a laminated heat insulating material as in Patent Document 1, the laminated heat insulating material peeled off or floated from the inner tank due to the suction force generated at the exhaust port will hinder the flow of exhaust gas, and sometimes it takes more time than expected to exhaust the inner and outer tanks to the target vacuum degree.

[0009] The present disclosure is completed in view of the above situation, and provides the following structure: in a multi-layer shell structure having a first shell, a second shell surrounding the first shell, and a stacked thermal insulation member arranged between the first shell and the second shell, when the space between the first shell and the second shell is forcibly exhausted from the exhaust port arranged in the second shell, the flow of the exhaust gas is not easily obstructed by the stacked thermal insulation member.

[0010] Means for solving problems

[0011] In order to solve the above-mentioned problems, a multilayer shell structure of one embodiment of the present invention comprises: a first shell; a stacked thermal insulation member surrounding the first shell; a second shell surrounding the stacked thermal insulation member and having an exhaust port; and an exhaust mask arranged at the exhaust port in an intermediate chamber between the first shell and the second shell, the exhaust mask comprising: a cover body having a main surface opposite to the surface of the stacked thermal insulation member surrounding the exhaust mask; and a main body connecting the cover body and the exhaust port, the main body having a connecting port connecting the intermediate chamber with the exhaust port and the opening axial direction being substantially parallel to the main surface of the cover body.

[0012] Effects of the Invention

[0013] According to the present disclosure, the following structure can be provided: in a multi-layer shell structure having a first shell, a second shell surrounding the first shell, and a stacked thermal insulation member arranged between the first shell and the second shell, when the space between the first shell and the second shell is forcibly exhausted from the exhaust port arranged in the second shell, the flow of the exhaust gas is not easily obstructed by the stacked thermal insulation member. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a diagram showing a schematic structure of a tank container having a multi-layer shell tank according to a first embodiment of the present disclosure.

[0015] Figure 2 It is a longitudinal section view of a multi-layer shell tank.

[0016] Figure 3 It is a cross-sectional view of the periphery of the exhaust port of the housing showing the structure of the exhaust cover.

[0017] Figure 4 It is a cross-sectional view of the periphery of the exhaust port of the housing showing the flow of exhaust gas in the exhaust cover.

[0018] Figure 5 It is a cross-sectional view showing a schematic structure of a vacuum multilayer tube according to a second embodiment of the present disclosure.

[0019] Figure 6 It is a cross-sectional view of the periphery of the exhaust port of the housing showing the structure of the exhaust cover. DETAILED DESCRIPTION

[0020] The multilayer shell structure disclosed in the present invention has a vacuum insulation layer, which has a first shell and a second shell surrounding the first shell, and a laminated insulation member is arranged between the first shell and the second shell and is decompressed to a state close to vacuum. Hereinafter, a first embodiment in which such a multilayer shell structure is applied to a multilayer shell tank and a second embodiment in which such a multilayer shell structure is applied to a vacuum multilayer tube 15 will be described.

[0021] [First embodiment]

[0022] The multilayer shell structure according to the first embodiment is a multilayer shell tank 11 . Figure 1 This is a diagram showing a schematic structure of a can container 1 having a multilayer shell structure according to a first embodiment of the present disclosure, and in this diagram, the inside of an outer shell 22 is shown through. Figure 1 The tank container 1 shown is used when transporting liquefied gas by ship or vehicle. Liquefied gas is, for example, a cryogenic liquid such as liquefied helium, liquefied hydrogen, and liquefied natural gas. The structure of the tank container 1 will be described below.

[0023] <Schematic structure of tank container 1>

[0024] The tank container 1 has a multilayer shell tank 11 as a multilayer shell structure and a frame 12 for supporting the multilayer shell tank 11. A substantially horizontal central axis C is defined in the multilayer shell tank 11, and the extending direction of the central axis C is referred to as the "axial direction X". The multilayer shell tank 11 is cylindrical with the central axis C as the axis, and the length direction of the multilayer shell tank 11 is substantially parallel to the axial direction X. The frame 12 has supporting portions arranged at both ends of the axial direction X of the multilayer shell tank 11. By supporting both ends of the length direction of the multilayer shell tank 11 with the frame 12, the multilayer shell tank 11 is held in the frame 12 in a manner that is non-movable relative to each other.

[0025] The multilayer shell tank 11 of the tank container 1 has a heat insulation structure to keep the stored liquefied gas at a very low temperature in order to suppress the gasification of the liquefied gas during transportation. The multilayer shell tank 11 has an inner shell 21 , an outer shell 22 , a heat shield 24 , and a refrigerant tank 46 .

[0026] The inner shell 21 is made of metal such as SUS, and has a cylindrical main body with the central axis C as the axis and end plates closing both ends of the main body. Liquefied gas is stored in the inner shell 21 in a sealed state. The outer shell 22 covers the entire periphery of the inner shell 21. The outer shell 22 is made of metal such as SS material or SUS, and has a cylindrical main body with the central axis C as the axis and end plates closing both ends of the main body. The outer shell 22 is larger than the inner shell 21 in order to store the inner shell 21 therein, and the outer wall of the inner shell 21 is separated from the inner wall of the outer shell 22.

[0027] The inner housing 21 is supported by the outer housing 22 via a support shaft 30 . The support shaft 30 is a shaft-shaped member extending in the axial direction X and arranged to overlap with the central axis C. The support shaft 30 is coupled to both the inner housing 21 and the outer housing 22 .

[0028] Both ends of the inner shell 21 in the axial direction X are supported by the outer shell 22 via a plurality of suspension rods 33. The base end of each suspension rod 33 is coupled to the end of the inner shell 21 in the longitudinal direction, and the front end of each suspension rod 33 is coupled to the outer shell 22. The plurality of suspension rods 33 are arranged to extend radially around the central axis C. In this way, the inner shell 21 is supported by the outer shell 22 in a state separated from the inner wall of the outer shell 22 (in other words, in a state of floating in the inner shell 22) through the support shaft 30 and the plurality of suspension rods 33.

[0029] Figure 2 1 is a longitudinal sectional view of the multilayer shell tank 11. Figure 1 and Figure 2 As shown, a hollow intermediate chamber 25 is formed between the inner shell 21 and the outer shell 22. The intermediate chamber 25 is decompressed to a state close to vacuum (hereinafter referred to as "vacuum state") in order to suppress convective heat transfer. In addition, a stacked thermal insulation member 26 covering the inner shell 21 is arranged in the intermediate chamber 25. The stacked thermal insulation member 26 is called MLI (Multilayer Insulation), which is a thermal insulation member composed of multiple layers of thin sheets. The structure of the stacked thermal insulation member 26 is not particularly limited, but preferably has thermal insulation performance corresponding to the temperature of the liquefied gas contained in the inner shell 21. The stacked thermal insulation member 26 is, for example, made by stacking a plurality of aluminum vapor-deposited films with low emissivity and a polyester non-woven fabric with low thermal conductivity to prevent the films from contacting each other, thereby suppressing radiant heat transfer.

[0030] A heat shield 24 is disposed in the intermediate chamber 25. The heat shield 24 absorbs a portion of the radiant heat from the outer shell 22 and blocks heat input to the inner shell 21. The heat shield 24 includes: a shield plate 23 that covers the inner shell 21 covered by the laminated heat insulating member 26; and a cooling pipe 41 that is disposed on the surface of the shield plate 23 and through which the refrigerant 44 flows. The shield plate 23 is formed of a plate made of a metal such as aluminum, and is cylindrical with the central axis C as the axis. The long side direction of the shield plate 23 is substantially parallel to the extension direction of the central axis C.

[0031] The cooling pipe 41 is arranged along the surface of the shielding plate 23. The refrigerant 44 supplied from the refrigerant tank 46 flows in the cooling pipe 41, and the refrigerant 44 exchanges heat with the shielding plate 23, thereby maintaining the surface temperature of the shielding plate 23 at an extremely low temperature. The refrigerant tank 46 is arranged between the end of the inner shell 21 in the axial direction X and the outer shell 22, and the support shaft 30 passes through the refrigerant tank 46 in the axial direction X. The refrigerant 44 is stored in the refrigerant tank 46. The refrigerant 44 is, for example, a low-temperature liquid such as liquid nitrogen. The type of the refrigerant 44 can be selected according to the type of liquefied gas stored in the inner shell 21.

[0032] The intermediate chamber 25 is provided with a laminated heat insulating member 27 covering the heat shield 24. The laminated heat insulating member 27 may be the same type of heat insulating member as the laminated heat insulating member 26 covering the inner shell 21, or may be a different type of heat insulating member. The structure of the laminated heat insulating member 27 is not particularly limited, but preferably has heat insulating performance corresponding to the temperature of the liquefied gas stored in the inner shell 21. In the multi-layer shell tank 11 having the laminated heat insulating member 27 covering the heat shield 24, the laminated heat insulating member 26 covering the inner shell 21 may be omitted.

[0033] <Exhaust Structure of Intermediate Chamber 25>

[0034] Here, the exhaust structure of the intermediate chamber 25 will be described. Figure 2 As shown, an exhaust port 63 is provided on the housing 22. Figure 2 Although one exhaust port 63 is shown in FIG. 1 , the exhaust port 63 may be provided at multiple locations of the housing 22. Although not particularly limited, Figure 2 In the example shown, an exhaust pipe 64 is arranged on the housing 22, penetrating the housing 22 in the wall thickness direction, and the exhaust port 63 is formed by the exhaust pipe 64. The direction perpendicular to the flow path cross section of the exhaust port 63 is defined as the "opening axial direction Y1" of the exhaust port 63. In the present embodiment, the opening axial direction Y1 of the exhaust port 63 is substantially parallel to the extension direction of the pipe axis of the exhaust pipe 64. One end of the exhaust pipe 64 is arranged in the intermediate chamber 25, and the other end of the exhaust pipe 64 is arranged outside the housing 22, and is closed in a manner that can be opened and closed by a valve 66. When the intermediate chamber 25 is evacuated, the vacuum pump 65 is connected to the exhaust pipe 64 via the valve 66 and the piping, and the intermediate chamber 25 is connected to the vacuum pump 65.

[0035] In the intermediate chamber 25 , the exhaust cover 7 is disposed at the exhaust port 63 . More specifically, the exhaust cover 7 is attached to the end of the exhaust pipe 64 . Figure 3 FIG. 2 is a cross-sectional view of the periphery of the exhaust port 63 of the housing 22 showing the structure of the exhaust cover 7. Figure 3 As shown, an exhaust mask 7 is arranged at the exhaust port 63 in a manner covering the exhaust port 63. The exhaust mask 7 has a main body 71 and a cover 72. In the present embodiment, the exhaust mask 7 and the exhaust pipe 64 are separate bodies, and the exhaust mask 7 is installed on the exhaust pipe 64, but the exhaust mask 7 may be integrally provided at the front end of the exhaust pipe 64, and the main body 71 of the exhaust mask 7 may be integrally formed at the front end of the exhaust pipe 64 and the cover 72 may be installed on the main body 71.

[0036] The main surface 72a of the cover 72 of the exhaust mask 7 faces the surface of the laminated heat insulating material 27 around the exhaust port 63. In addition, the laminated heat insulating material 27 around the exhaust port 63 at least includes a portion of the laminated heat insulating material 27 that exists in the region extending the exhaust port 63 in the opening axial direction Y1. The surface of the laminated heat insulating material 27 around the exhaust mask 7 is sometimes not a plane but a curved surface, and the main surface 72a of the cover 72 is not limited to a plane. Therefore, although the main surface 72a of the cover 72 faces the surface of the laminated heat insulating material 27, it is not limited to be parallel to these surfaces.

[0037] The main body 71 connects the cover 72 and the exhaust port 63. The main body 71 of the exhaust cover 7 of this embodiment is cylindrical and extends substantially parallel to the opening axial direction Y1 of the exhaust port 63. However, the shape of the main body 71 is not limited to this embodiment.

[0038] A plurality of communication ports 73 are provided on the main body 71 of the exhaust cover 7. The plurality of communication ports 73 are preferably dispersedly arranged in the circumferential direction in the main body 71. Each communication port 73 connects the intermediate chamber 25 with the exhaust port 63. In addition, when the direction perpendicular to the flow path cross section of the communication port 73 is set as the "opening axial direction Y2" of the communication port 73, the opening axial direction Y2 of each communication port 73 is substantially parallel to the main surface 72a of the cover body 72. Here, "substantially parallel" includes parallelism and approximately parallelism to the extent that it is not strictly parallel but can exert the rectification function described later. In the present embodiment, the opening axial direction Y2 of each communication port 73 is substantially perpendicular to the opening axial direction Y1 of the exhaust port 63.

[0039] In order to prevent the flow rate of the gas passing through the exhaust port 63 by the exhaust cover 7 from being reduced, the total flow path cross-sectional area of ​​the plurality of communication ports 73 is preferably substantially the same as the flow path cross-sectional area of ​​the exhaust port 63 .

[0040] Figure 4 FIG. 2 is a cross-sectional view of the exhaust port 63 and the periphery of the housing 22 showing the flow of the exhaust gas in the exhaust cover 7. In this figure, the flow of the exhaust gas is shown by arrows. Figure 4 As shown, when the vacuum pump 65 is connected to the exhaust pipe 64 and the vacuum pump 65 is running, a forced exhaust flow is generated at the exhaust port 63. The gas in the intermediate chamber 25 enters the exhaust pipe 64 through the communication port 73 of the exhaust cover 7. Due to the rectifying effect of the exhaust cover 7, the flow of the gas entering the exhaust pipe 64 from the intermediate chamber 25 through the exhaust cover 7 is substantially parallel to the opening axial direction Y2 of the communication port 73. The flow of the gas entering the exhaust pipe 64 is rectified by the exhaust pipe 64 to be substantially parallel to the opening axial direction Y1 of the exhaust port 63.

[0041] Since the cover 72 of the gas exhaust mask 7 is present at the front end of the opening axial direction Y1 of the exhaust port 63 to block the passage of the gas, the gas in the intermediate chamber 25 cannot enter the exhaust port 63 substantially parallel to the opening axial direction Y1 of the exhaust port 63. Therefore, in the intermediate chamber 25, a flow of exhaust gas substantially parallel to the opening axial direction Y2 of the communication port 73 is generated around the exhaust mask 7. The opening axial direction Y2 of the communication port 73 is substantially parallel to the in-plane direction of the surface of the laminated heat insulation member 27 around the exhaust mask 7. That is, around the exhaust mask 7, there is almost no flow of gas that stretches the laminated heat insulation member 27 in the out-of-plane direction. Therefore, it is possible to suppress the laminated heat insulation member 27 around the exhaust mask 7 from peeling off or floating due to the flow of exhaust gas and moving from a fixed position, and it is possible to prevent the exhaust port 63 from being blocked by the laminated heat insulation member 27 that moves from a fixed position. In this way, the flow of exhaust gas is not blocked by the laminated heat insulation member 27, so the intermediate chamber 25 can be quickly exhausted to the target vacuum degree.

[0042] In the present embodiment, the multilayer shell tank 11 is a transport tank possessed by the tank container 1, but the structure of the multilayer shell tank 11 can also be applied to storage tanks installed on the ground, fuel tanks and storage tanks carried on floating structures such as ships. In addition, the multilayer shell tank 11 is not limited to a double-layer shell tank, and can also have a multilayer shell with more than three layers. The multilayer shell tank in this case has nothing to do with the number of shells, as long as it has a first shell and a second shell adjacent to each other inside and outside and a stacked heat insulating member arranged between the first shell and the second shell, and the second shell has an exhaust port for decompressing the space between the first shell and the second shell, and an exhaust mask 7 is arranged at the exhaust port.

[0043] [Second embodiment]

[0044] Next, a second embodiment of the present disclosure will be described. Figure 5 2 is a cross-sectional view showing a schematic structure of a vacuum multilayer tube 15 according to a second embodiment of the present disclosure. Figure 5 As shown, the multilayer shell structure of the second embodiment is a vacuum multilayer tube 15. The vacuum multilayer tube 15 is used as a pipe for passing liquid or gas at a very low temperature, for example.

[0045] The vacuum multilayer tube 15 includes an inner shell 121 and an outer shell 122 surrounding the inner shell 121. The inner shell 121 and the outer shell 122 are both tubes, and the inner shell 121 and the outer shell 122 constitute a double-layer tube. A very low temperature liquid or gas passes through the inner shell 121. A hollow intermediate chamber 125 is formed between the inner shell 121 and the outer shell 122. A laminated heat insulating member 126 covering the inner shell 121 is arranged in the intermediate chamber 125. In addition, the intermediate chamber 25 is in a vacuum state in order to suppress convective heat transfer, and the intermediate chamber 125 functions as a vacuum heat insulating layer.

[0046] Here, the exhaust structure of the intermediate chamber 125 is described. The housing 122 is provided with an exhaust port 163. Figure 5 Although one exhaust port 163 is shown in FIG. 1 , the exhaust port 163 may be provided at multiple locations of the housing 122. Although not particularly limited, Figure 5 In the example shown, an exhaust pipe 164 is arranged on the housing 122, penetrating the housing 122 in the wall thickness direction, and the exhaust port 163 is formed by the exhaust pipe 164. One end of the exhaust pipe 164 is arranged in the intermediate chamber 125, and the other end of the exhaust pipe 164 is arranged outside the housing 122, and is closed in a manner that can be opened and closed by a valve 166. When the intermediate chamber 125 is evacuated, the vacuum pump 65 is connected to the exhaust pipe 164 via the valve 166 and the piping, and the intermediate chamber 125 is communicated with the vacuum pump 65.

[0047] In the intermediate chamber 125 , the exhaust cover 7 is disposed at the exhaust port 163 . More specifically, the exhaust cover 7 is attached to the end of the exhaust pipe 164 . Figure 6 1 is a cross-sectional view of the periphery of the exhaust port 163 of the housing 122 showing the structure of the exhaust cover 7. Figure 6 As shown in FIG. 1 , the structure of the exhaust cover 7 is substantially the same as that of the exhaust cover 7 of the first embodiment, and therefore the same reference numerals are used for the same or similar components as those of the first embodiment, and detailed description thereof will be omitted.

[0048] The exhaust cover 7 is disposed at the exhaust port 163 so that the main surface 72a of the cover body 72 faces the surface of the laminated heat insulator 126. The exhaust cover 7 is disposed so that the extension direction of the main body 71 is substantially parallel to the opening axial direction Y1 of the exhaust port 163.

[0049] In the vacuum multilayer tube 15 of the above structure, when the vacuum pump 65 is connected to the exhaust pipe 164 and the vacuum pump 65 is operated, a forced exhaust flow is generated at the exhaust port 163. The gas in the intermediate chamber 125 enters the exhaust pipe 164 through the communication port 73 of the exhaust cover 7. Due to the rectifying effect of the exhaust cover 7, the flow of the gas entering the exhaust pipe 164 from the intermediate chamber 125 through the exhaust cover 7 is substantially parallel to the opening axial direction Y2 of the communication port 73. The flow of the gas entering the exhaust pipe 164 is rectified by the exhaust pipe 164 to be substantially parallel to the opening axial direction Y1 of the exhaust port 63.

[0050] Since the cover 72 of the exhaust mask 7 is present at the front end of the opening axial direction Y1 of the exhaust port 163, the gas in the intermediate chamber 125 cannot enter the exhaust mask 7 substantially parallel to the opening axial direction Y1 of the exhaust port 163. Therefore, in the intermediate chamber 125, around the exhaust mask 7, there is almost no flow of exhaust gas substantially parallel to the opening axial direction Y1 of the exhaust port 163, but there is a flow of exhaust gas substantially parallel to the opening axial direction Y2 of the communication port 73. The opening axial direction Y2 of the communication port 73 is substantially parallel to the in-plane direction of the surface of the laminated heat insulating member 126 around the exhaust mask 7. That is, around the exhaust mask 7, there is almost no flow of gas that pulls the laminated heat insulating member 126 in the out-of-plane direction. Therefore, it is possible to suppress the laminated heat insulating member 126 around the exhaust mask 7 from peeling off or floating due to the flow of exhaust gas and moving from a fixed position, and it is possible to prevent the exhaust port 163 from being blocked by the laminated heat insulating member 126 that moves from a fixed position. In this way, the flow of exhaust gas is not blocked by the laminated heat insulating material 126 , and thus the intermediate chamber 125 can be rapidly evacuated to a target vacuum degree.

[0051] 〔Summarize〕

[0052] The multilayer shell structure 11, 15 of the first item of the present disclosure comprises: a first shell 21, 121; a stacked heat insulating member 27, 126, which surrounds the first shell 21, 121; a second shell 22, 122, which surrounds the stacked heat insulating member 27, 126 and has an exhaust port 63, 163; and an exhaust mask 7, which is arranged at the exhaust port 63, 163 in the intermediate chamber 25, 125 between the first shell 21, 121 and the second shell 22, 122, the exhaust mask 7 comprises: a cover body 72, which has a main surface 72a opposite to the surface of the stacked heat insulating member 27, 126 around the exhaust mask 7; and a main body 71, which connects the cover body 72 and the exhaust port 63, 163, and has a connecting port 73 that connects the intermediate chamber 25, 125 with the exhaust port 63, 163 and the opening axial direction Y2 is substantially parallel to the main surface 72a of the cover body 72.

[0053] In the above description, the multilayer shell structures 11 and 15 correspond to the multilayer shell tank 11 in the first embodiment and to the vacuum multilayer tube 15 in the second embodiment. The first shells 21 and 121 correspond to the inner shell 21 in the first embodiment and to the inner shell 121 in the second embodiment. In addition, the second shells 22 and 122 correspond to the outer shell 22 in the first embodiment and to the outer shell 122 in the second embodiment.

[0054] In the multilayer shell structure 11, 15 of the above-mentioned structure, when suction force is generated at the exhaust port 63, 163 in order to forcibly exhaust the intermediate chamber 25, 125, the gas in the intermediate chamber 25, 125 reaches the exhaust port 63, 163 through the communication port 73 of the exhaust cover 7. Due to the rectifying effect of the exhaust cover 7, the flow of the gas from the intermediate chamber 25 through the exhaust cover 7 to the exhaust port 63, 163 is substantially parallel to the opening axial direction Y2 of the communication port 73. Therefore, in the intermediate chamber 25, 125, a flow of exhaust gas substantially parallel to the opening axial direction Y2 of the communication port 73 is generated around the exhaust cover 7. The opening axial direction Y2 of the communication port 73 is substantially parallel to the in-plane direction of the surface of the laminated heat insulating material 27, 126 around the exhaust cover 7. That is, around the exhaust cover 7, there is almost no flow of gas that pulls the laminated heat insulating material 27, 126 in the out-of-plane direction. Therefore, the laminated heat insulating material 27, 126 around the exhaust cover 7 can be prevented from peeling off or floating due to the flow of the exhaust gas and moving from the fixed position, and the exhaust port 63, 163 can be prevented from being blocked by the laminated heat insulating material 27, 126 moving from the fixed position. In this way, the flow of the exhaust gas is not hindered by the laminated heat insulating material 27, 126, so the intermediate chamber 25, 125 can be quickly exhausted to the target vacuum degree.

[0055] The multilayer shell structure 11 , 15 according to the second aspect of the present disclosure is the multilayer shell structure 11 , 15 according to the first aspect, wherein the plurality of communication openings 73 are dispersedly arranged in the main body 71 .

[0056] Thus, the gas in the intermediate chamber 25 , 125 can be dispersed from a plurality of locations around the exhaust cover 7 and enter the exhaust ports 63 , 163 .

[0057] The multilayer shell structure 11 , 15 according to the third aspect of the present disclosure is the multilayer shell structure 11 , 15 according to the second aspect, wherein the sum of the opening areas of the plurality of communication ports 73 is substantially the same as the opening area of ​​the exhaust ports 63 , 163 .

[0058] This can reduce the degree of reduction in the flow rate of gas passing through the exhaust ports 63 and 163 caused by the exhaust cover 7 .

[0059] The multilayer shell structure 11 according to claim 4 of the present disclosure is the multilayer shell structure 11 according to any one of claims 1 to 3, further comprising a heat shield 24 disposed between the first shell 21 and the laminated heat insulating material 27 and surrounding the first shell 21 .

[0060] As described above, since the multi-layer shell can 11 includes the heat shield 24 that shields the first shell 21 from radiant heat, the multi-layer shell can 11 is suitable as a transport container included in the can container 1 .

[0061] The above discussion of the present disclosure is presented for the purpose of illustration and description, and is not intended to limit the present disclosure to the methods disclosed in this specification. For example, in the above detailed description, the various features of the present disclosure are summarized into two embodiments for the purpose of rationalizing the present disclosure, but several of the multiple features may be combined. In addition, the multiple features included in the present disclosure may also be combined with alternative embodiments, structures or methods other than those described above.

[0062] Description of symbols

[0063] 1: tank container; 7: exhaust cover; 11: multilayer shell tank (an example of a multilayer shell structure); 15: vacuum multilayer tube (an example of a multilayer shell structure); 21, 121: inner shell (an example of the first shell); 22, 122: outer shell (an example of the second shell); 24: heat shielding part; 25, 125: intermediate chamber; 26, 27, 126: laminated insulation part; 63, 163: exhaust port; 64, 164: exhaust pipe; 71: main body; 72: cover body; 72a: main surface; 73: connecting port; Y2: opening axial direction.

Claims

1. A multilayer shell structure, comprising: Shell 1; A laminated heat-insulating member surrounding the first shell; a second shell surrounding the laminated thermal insulation member and having an exhaust port; and an exhaust mask disposed at the exhaust port in an intermediate chamber between the first shell and the second shell, The exhaust mask has: a cover having a main surface opposite to a surface of the laminated heat insulating material surrounding the exhaust cover; and A main body portion connects the cover body and the exhaust port, and has a communication port that connects the intermediate chamber and the exhaust port and has an opening axial direction that is substantially parallel to the main surface of the cover body.

2. The multilayer shell structure according to claim 1, wherein: The plurality of communication ports are dispersedly arranged on the main body.

3. The multilayer shell structure according to claim 2, wherein: The sum of the opening areas of the plurality of communication ports is substantially the same as the opening area of ​​the exhaust port.

4. The multilayer shell structure according to claim 1 or 2, wherein: The multilayer shell structure further includes a heat shield disposed between the first shell and the laminated heat insulating material and surrounding the first shell.

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