CN112119257B

CN112119257B - Closed tank wall comprising a sealing film

Info

Publication number: CN112119257B
Application number: CN201980030751.9A
Authority: CN
Inventors: 尼古拉·洛兰; 马蒂厄·马勒姆; 亚历山大·勒普伦特
Original assignee: Gaztransport et Technigaz SA
Current assignee: Gaztransport et Technigaz SA
Priority date: 2018-05-07
Filing date: 2019-05-03
Publication date: 2023-03-24
Anticipated expiration: 2039-05-03
Also published as: KR20210005680A; WO2019215404A1; FR3080905B1; KR102657084B1; FR3080905A1; CN112119257A; SG11202011005PA

Abstract

The present invention relates to a closed tank wall for storing a fluid, said closed tank wall comprising: a support surface (11) comprising at least one groove (12) cut in the thickness direction of the tank wall and extending in the longitudinal direction; and a metal sealing membrane (50, 52) carried by the support surface (6, 11), the metal sealing membrane comprising at least one metal support (16) carried by the support surface (6, 11), said metal support (16) comprising a first anchoring wing and a second anchoring wing attached to each other in a sealed manner, and the anchoring wings each comprising an upper portion on the support surface (11), a base retained in the groove (12), and an arm connecting the upper portion to the base; wherein the arms of the anchoring wings are elastically yieldingly deformable in the transverse direction to allow the upper portions of the anchoring wings to move in the transverse direction relative to each other.

Description

Closed tank wall comprising a sealing film

Technical Field

The present invention relates to the field of sealed tanks, in particular for storing or transporting fluids, and in particular to the field of sealed and thermally insulated tanks for liquefied gases at low temperatures.

Sealed and thermally insulated tanks are particularly used for storing liquefied gases stored at atmospheric pressure, such as Liquefied Natural Gas (LNG) or Liquefied Petroleum Gas (LPG). These tanks may be installed onshore or on a floating structure.

Background

Storage or transport tanks for liquefied gases at low temperatures are known, for example from WO2012072906 or FR3054872, in which the or each sealing membrane, in particular the primary sealing membrane in contact with the product contained in the tank, is composed of a thin metal sheet called a metal rim connected to one another in a sealing manner to ensure that the tank is sealed.

The metal edge strip is fixed to the thermal insulation barrier in this type of can. Specifically, the upper surface of the thermal insulation barrier has a groove that is dug out in the thickness direction from the upper surface and extends in the longitudinal direction of the thermal insulation barrier. A welding support including a base and an arm connected to the base is slidably inserted into the groove. The base is received in the recess to retain the weld support on the thermally insulating barrier in a direction perpendicular to the upper surface. The arms of the welding support protrude above the upper surface.

Two metal edge strips are arranged on either side of the welding support. The metal edgings each have a flat middle portion that rests on the upper surface. These metal edgings also have raised side edges. The raised edge of each of the two adjacent metal edge strips is welded on either side of the welding support arm. The weld supports are typically not as thick as the edge bars.

The raised edge thus forms a deformable bellows with the welded support, making it possible to absorb the forces associated with the shrinkage of the sealing membrane, for example when cryogenic liquid is loaded into the tank.

Such a membrane may be referred to as a membrane having an inwardly directed bellows that is oriented toward the interior of the container.

From WO2015022473 also a membrane tank is known, in which a first tank wall and an adjacent second tank wall form a corner joint, the tank further comprising sealing corners at the corner joint. In this case, the plates adjacent to the corner joint are connected to one another by means of two reinforcing wings of the corner fitting in the groove. Thus, the fixation is on the outward side of the tank. However, a metal plate called corner angle iron also secures the two plates above the support surface to cover the securing area of the corner joint and the reinforcing wings, so that there is no possibility of any deformable bellows at the connection between the two membrane plates.

Disclosure of Invention

During the transport of the fluid contained in the sealed tank, in particular when the tank is not completely full, there is a sloshing of the fluid, causing it to move from one wall to the other. Thus, sloshing of the fluid exerts stress on the walls of the tank, in particular on these projecting portions, such as the raised edges. In prior art cans, these stresses on the raised edges can cause the raised edges to bend. The curved raised edge no longer effectively acts as a bellows to absorb the shrinkage of the membrane and may cause damage to the membrane which would compromise the sealing of the can.

The idea forming the basis of the present invention is to reduce or prevent the risk of the edges of the projections bending in order to prevent any damage to the sealed can.

Another idea forming the basis of the present invention is to hold the deformable bellows on the sealing membrane to absorb the forces associated with the shrinkage of the membrane.

Another idea forming the basis of the present invention is to provide a sealing membrane which can be used in a sealed can for transporting or storing cold products and which maximizes the useful volume of the can.

According to one embodiment, the present invention provides a sealed tank wall for storing fluid, comprising:

-a support surface comprising at least one groove hollowed out in the thickness direction of the tank wall and extending in a longitudinal direction;

a metal sealing membrane carried by the support surface in the longitudinal direction, the metal sealing membrane comprising at least one metal support, preferably a plurality of metal supports, carried by the support surface, said metal supports comprising a first anchoring wing and a second anchoring wing sealingly fixed to each other, the anchoring wings each comprising an upper portion extending in the transverse direction above the support surface such that the upper portion of the first anchoring wing extends on one side of the groove and the upper portion of the second anchoring wing extends on the other side of the groove, the anchoring wings each further comprising a base which is held in the groove of the support surface in a direction perpendicular to the support surface, the base having a degree of freedom in the longitudinal direction, and the anchoring wings each comprising an arm connecting the upper portion to the base;

wherein the arms of the anchoring wings are elastically deformable in bending in the transverse direction to allow the upper portions of the anchoring wings to move in the transverse direction relative to each other.

Thanks to these features, the sealing can wall does not have raised edges to constitute its sealing membrane, but at least one metal support, so that there are no longer any protruding parts affected by the sloshing of the fluid and the risk of these raised edges bending. Furthermore, the metal support makes it possible to obtain a membrane with an outward bellows, one or more bellows being oriented towards the outside of the tank, one or more bellows making it possible to absorb the forces associated with the contraction of the membrane.

According to one embodiment, the support surface comprises a plurality of grooves and the sealing membrane comprises a plurality of metal supports, at least one base of the anchoring wings of the plurality of metal supports being retained in each of the grooves.

According to one embodiment, the at least one metal support is made of any type of metal, such as stainless steel.

According to one embodiment, at least one metal support is made of a metal having a low thermal expansion coefficient, for example, the metal may be of 1.2 to 2.0 x 10 ^-6 K ^-1 An iron-nickel alloy with a thermal expansion coefficient in between, or an iron alloy with a high manganese content, the expansion coefficient of which is typically about 7.5 x 10 ^-6 K ^-1 。

According to one embodiment, the recess comprises a flared portion where the recess opens out. The flared portion at which the groove opens out can be made, for example, using chamfers on either side of the groove.

Thus, the flared portion at which the groove opens outwards makes it possible to increase the space in which the anchoring wings can deform and thus to enhance the bellows effect by increasing the possible lateral movement of the upper portion of the anchoring wings.

According to one embodiment, the transverse dimension of the groove is greater than twice the thickness of the anchoring wing. The transverse dimension of the recess may for example be more than five times the thickness of the anchoring wing.

Thanks to these features, the transverse dimensions of the groove make it possible to leave a gap between the metal support and the groove, allowing a space to be left where the anchoring wings can deform and thus enhancing the bellows effect of the membrane.

According to one embodiment, the anchoring wings are welded to each other inside the groove by a first stage longitudinal weld.

Thus, the welding makes it possible to create a seal between the two anchoring wings. Furthermore, the welding is performed inside the groove, since the distance in the thickness direction of the wall between the upper part of the anchoring wing and the first-stage longitudinal weld makes it possible to create and reinforce the bellows effect required by the membrane for its shrinkage. In particular, the greater the distance between the upper portion of the anchoring wing and the first stage longitudinal weld, the greater the lateral movement of the membrane will be.

According to one embodiment, the first stage longitudinal welds are located at the arms of the anchoring wings.

According to one embodiment, the distance in the thickness direction of the wall between the upper portion of the anchoring wing and the first stage longitudinal weld is between 15mm and 50 mm.

According to one embodiment, the metal support comprises a connecting portion which connects the bases of the anchoring wings to each other hermetically inside the groove.

By means of these features, the connection portion makes it possible to create a seal between the two anchoring wings. Furthermore, since it connects the base of each of the anchoring wings, the connecting portion is spaced from the upper portion by the length of the anchoring wing arm. Thus, the anchoring wing arms may be flexurally elastically deformed over their entire length, which allows a potentially large movement of the upper part in the transverse direction.

According to one embodiment, the metal sealing membrane comprises a plurality of said metal supports arranged parallel to each other, wherein the upper portions of the anchoring wings of two adjacent metal supports are connected in a sealing manner directly or indirectly.

According to one embodiment, the metal sealing membrane comprises a metal strip resting on the supporting surface, arranged parallel to the metal supports, and wherein a first edge of the metal strip is welded by a first second stage longitudinal weld to an upper portion of a first anchoring wing of a first one of the metal supports, and a second edge of the metal strip is welded by a second stage longitudinal weld to an upper portion of a second anchoring wing of a second one of the metal supports.

According to one embodiment, the metal sealing membrane comprises a plurality of metal strips, one or each of which is arranged parallel to the metal support.

Thus, the membrane comprises one or more metal strips and one or more metal supports connecting each strip to each other to form a fluid-tight assembly.

According to one embodiment, the thickness of the metal support is greater than or equal to the thickness of the metal strip.

According to one embodiment, the thickness of the metal support is between 0.7mm and 1.5mm, the thickness of the strip being for example less than or equal to 0.7mm.

According to one embodiment, the one or more metal strips are made of any type of metal, such as stainless steel.

According to one embodiment, said one or more metal strips are made of a metal having a low thermal expansion coefficient, for example, the metal may be of a material having a thermal expansion coefficient of between 1.2 and 2.0 x 10 ^-6 K ^-1 An iron-nickel alloy with a thermal expansion coefficient in between, or an iron alloy with a high manganese content, the expansion coefficient of which is typically about 7.5 x 10 ^-6 K ^-1 。

According to one embodiment, one end of the metal strip is located between the support surface and the upper portion of the anchoring wing, and the second-stage longitudinal weld is made on the upper portion, for example at one end of the upper portion, to connect the metal strip to the upper portion.

Thanks to these features, placing the upper part of the anchoring wing on the metal strip makes it possible to facilitate the welding of metal sheets of different thicknesses.

According to one embodiment, the cross-section of the metal strip comprises a flat middle portion resting on the support surface and at least one offset portion parallel to and at a distance from the support surface, between which an upper portion of the anchoring wing is located, and wherein a second-stage longitudinal weld connecting said upper portion and an edge of the metal strip is made on the offset portion of the metal strip.

These features make it easier to fix the anchoring wings to the strip, since the overlap of the offset portion with the upper portion facilitates welding and also allows for manufacturing tolerances for larger parts.

According to one embodiment, the offset portion is formed by stamping one end of the metal strip or by welding an attached plate to one end of the metal strip.

According to one embodiment, the one or more metal strips have two offset portions on either side of the flat middle portion.

According to one embodiment, the distance between the support surface and the offset portion is substantially equal to or greater than the thickness of the upper portion of the anchoring wing, preferably substantially equal.

According to one embodiment, the cross-section of the metal support or of the upper portion of the metal support comprises a flat portion resting on the support surface and at least one offset portion parallel to and at a distance from the support surface, a portion of the metal strip being located between the support surface and the offset portion, and wherein a second-stage longitudinal weld connecting said upper portion and an edge of the metal strip is made on the offset portion of the upper portion.

According to one embodiment, the recess is a primary recess and the support surface comprises at least one secondary recess which is hollowed out in the thickness direction and extends in the longitudinal direction close to the primary recess, and preferably closely close to the primary recess, and wherein at least one part or an upper part of the anchoring wing is located in the secondary recess. At least one portion of the anchoring wing located in the second-stage groove or an upper portion may for example be below the metal strip.

It is therefore easier to fix the anchoring wing to the strip, since the overlap of the strip with the upper part located in the second-stage groove facilitates welding and also allows manufacturing tolerances for larger parts.

According to one embodiment, the containment tank wall comprises a thermal insulation layer in the second stage groove below the upper portion of the anchoring wing.

According to one embodiment, the support surface comprises two secondary grooves on either side of the primary groove.

According to one embodiment, the dimension of the second-stage groove in the thickness direction is substantially equal to or greater than the thickness of the upper portion of the anchoring wing.

According to one embodiment, the dimension of the second-stage groove in the transverse direction is substantially equal to or greater than the dimension of the upper portion of the anchoring wing in the transverse direction.

According to one embodiment, the recess has an inlet region extending in the thickness direction, the recess comprising a retaining region arranged below the inlet region and extending parallel to the support surface over a width larger than the inlet region, and wherein the base of the at least one anchoring wing of the metal support is accommodated in the retaining region.

According to one embodiment, the holding area extends parallel to the support surface on either side of the inlet area.

According to one embodiment, the base of the or each anchoring wing is flat in shape.

According to one embodiment, the recess comprises at least one fastener configured to retain one of the bases of the metal support in the recess, preferably the recess comprises two fasteners to retain the base of the first anchoring wing and the base of the second anchoring wing.

According to one embodiment, one of the base portions of the metal support has a circular arc shape, and the fastener has a complementary circular arc portion, so that the base portion of the metal support and the circular arc portion of the fastener fit inside one another. Preferably, the two bases of the metal support each have a circular arc shape and the two fasteners each have complementary circular arc portions, so that the corresponding bases of the metal support and the circular arc portions of the fasteners fit inside one another.

According to one embodiment, the containment tank wall includes a thermal insulation barrier including a top panel including a support surface. Such thermal insulation barriers can be produced in various ways according to the techniques described, for example, in publications FR-A-2798902, WO-A-2017103500 or WO-A-2017207938.

According to one embodiment, the thermal insulation barrier is a primary thermal insulation barrier and the sealing membrane is a primary sealing membrane, and wherein the sealing can wall comprises a secondary thermal insulation barrier and a secondary sealing membrane arranged below the primary thermal insulation barrier.

According to one embodiment, the present invention provides a polyhedral sealed can comprising a plurality of can walls sealingly secured to one another to form a polyhedral interior space for storing fluid, wherein one or more of the can walls are as described above.

According to other advantageous embodiments, such a tank may have one or more of the following features.

According to an embodiment, the tank may comprise one or more tank walls from the list of tank walls:

ceiling wall

-a bottom wall

-one or more cofferdam side walls connecting the bottom wall to the ceiling wall,

-one or more side walls connecting the one or more cofferdam side walls,

-one or more lower walls forming a chamfer connecting one or more side walls to the bottom wall, and

-forming one or more upper walls of a chamfer connecting one or more side walls to the ceiling wall;

one or more of the listed tank walls may be a tank wall as described above.

Such tanks may form part of an onshore storage facility, e.g. for storing LNG, or may be installed on a coastal or deep water floating structure, in particular an LNG carrier, a Floating Storage and Regasification Unit (FSRU), a remote floating production and storage unit (FPSO), etc. Such tanks may also be used as fuel tanks in any type of transport vessel.

According to one embodiment, the invention also provides a transport vessel for transporting liquid products, comprising a hull and a tank according to the invention arranged in the hull.

According to one embodiment, the invention provides a method for loading or unloading such a transport vessel, wherein the liquid product is transferred from or from the floating or onshore storage facility to the sealed tanks of the transport vessel via insulated pipelines.

According to one embodiment, the invention also provides a transfer system for transferring a liquid product, the system comprising: the above-mentioned transport ship; an insulated pipeline arranged to connect a sealed tank installed in the hull of a transport vessel to a floating or onshore storage facility; and a pump for pumping a stream of cold liquid product from the floating or onshore storage facility to the seal tank of the transport vessel or from the seal tank of the transport vessel to the floating or onshore storage facility through the insulated pipeline.

Drawings

The invention will be better understood and other objects, details, characteristics and advantages thereof will become more clearly apparent in the course of the following description of several particular embodiments of the invention, provided by way of non-limiting illustration only, with reference to the accompanying drawings.

Fig. 1 is a partial perspective view of the wall of a sealed and insulated tank according to the invention with a portion cut away.

Fig. 2 is a schematic cross-sectional view of a metal support anchored in a support surface, the base of the support being flat.

Fig. 3 is a schematic cross-sectional view of a metal support anchored in a support surface, the base of the support being flat and the support being welded under a metal strip.

Fig. 4 is a schematic cross-sectional view of a metal support anchored in a support surface, the base of which is radiused and fixed to a fastener/fastener, and which is welded to a metal strip.

Fig. 5 is a partial perspective view of a metal support anchored in a support surface according to fig. 4.

Fig. 6 is a schematic cross-sectional view of a metal support anchored in a support surface, the surface having a second stage of grooves.

Fig. 7 is a schematic cross-sectional view of a metal support anchored in a support surface, the support being welded over a metal strip.

Fig. 8 schematically depicts, with a part cut away, a transport vessel comprising a sealed tank for storing fluid and a quay for loading/unloading the tank.

Detailed Description

In the following description, reference is made to the sealing film in the context of a sealing can. Such tanks comprise an inner space formed by a plurality of tank walls, which inner space is intended to be filled with, for example, a combustible gas or a non-combustible gas. The gas may in particular be a Liquefied Natural Gas (LNG), that is to say a gas mixture comprising mainly methane and, in small proportions, one or more other hydrocarbons, such as ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane and nitrogen. The gas may also be ethane or Liquefied Petroleum Gas (LPG), that is, a mixture of hydrocarbons mainly comprising propane and butane obtained from the refining of petroleum.

Conventionally, the longitudinal direction is defined by the length direction of the tank wall. The thickness direction is defined by the thickness direction of the tank wall. The transverse direction is defined by the width direction of the tank wall. The longitudinal direction, the transverse direction and the thickness direction form a three-dimensional orthogonal coordinate system.

The sealing

films

50, 52 rest on the support surface 11 formed by the

thermal insulation barriers

51, 53 of the can 71. The sealing

films

50, 52 have a repeating structure which alternately comprises, on the one hand, a sheet metal strip 22 arranged on the support surface 11 and, on the other hand, an elongated metal support 16 connected to the support surface 11 and extending parallel to the sheet metal strip 22 over at least a part of the length of the sheet metal strip 22. One end of the sheet metal strip 22 is welded against the adjacent metal support 16. Such a structure is for example used in the NO96 tanks sold by the applicant for LNG carriers.

Referring to fig. 1, the support structure of the carrier is in this case constituted by the inner walls 1 of the double hull 72 of the carrier 70. In a manner known per se, the tank 71 comprises a second stage of thermal insulation barriers 53 fixed to the support structure of the carrier 70. The second stage thermal insulation barrier 53 is constituted by a plurality of parallelepipedic second stage insulation compartments 2 arranged side by side so as to substantially cover the inner surface of the support structure.

Each second-stage insulation compartment 2 is constituted by a parallelepiped box made of plywood, which internally comprises a load-bearing partition 3 and a non-load-bearing partition 4 intended only to ensure the relative positioning of the load-bearing partition 3, said partitions being interposed between a plywood bottom panel 5 and a plywood top panel 6. The bottom wall 5 of the compartment 2 projects laterally on both small sides of the compartment, so that in each corner of the compartment a bead 7 is fixed on this projection, the bead having the thickness of said projection. The compression strips 7 interact with members for fixing the compartments 2 to the support structure.

Each compartment 2 is filled with a thermally insulating particulate material, such as perlite or glass wool. The floor 5 of each compartment 2 rests on a bead of polymerizable resin 8, which itself rests on the support structure 1 by means of kraft paper 9 to prevent the resin of the glue bead from adhering to the support structure and thus allowing dynamic deformation of the support structure without the compartment 2 being subjected to forces due to said deformation. The purpose of the beads of polymerizable resin 8 is to compensate for the difference between the theoretical surface provided for the support structure and the imperfect surface due to manufacturing tolerances. The top panel 6 of the second stage insulation compartment 2 further comprises a pair of parallel grooves 12, for example substantially inverted I-, L-or T-shaped, to receive metal supports 16, for example L-, T-or J-shaped.

The metal support 16 has a first anchoring wing 17 and a second anchoring wing 18 fixed to each other to form a sealed metal support 16. The anchoring

wings

17, 18 each comprise an upper portion 21 extending in the transverse direction above the support surface 11. The upper portion 21 of the first anchoring wing 17 extends on one side of the groove 12, while the upper portion 21 of the second anchoring wing 18 extends on the other side of the groove 12.

The anchoring

wings

17, 18 each further comprise a base 19 which is held in the recess 12 of the support surface 11 in a direction perpendicular to the support surface 11, the base having a degree of freedom in the longitudinal direction. Each of the anchoring

wings

17, 18 also comprises an arm 20 connecting the upper portion 21 to the base 19.

The secondary sealing film 52 is formed of a plurality of metal strips 22 having a thickness of about 0.7mm. The ends of each metal strip 22 are welded to the above-mentioned metal support at the upper portions 21 of the anchoring

wings

17, 18. The metal strip 22 is made of a strong metal such as stainless steel or of a metal having a low coefficient of thermal expansion, which may be, for example, between 1.2 and 2.0 x 10 ^-6 K ^-1 An iron-nickel alloy with a thermal expansion coefficient in between, or an iron alloy with a high manganese content, the expansion coefficient of which is typically about 7.5 x 10 ^-6 K ^-1 。

On the second-stage sealing film 52 is mounted a first-stage thermal insulation barrier 51 also constituted by a plurality of first-stage insulation compartments 10 having a similar structure to the second-stage insulation compartments 2. Each first stage insulating compartment 10 is constituted by a parallelepiped box made of plywood having a height smaller than the compartment 2 filled with particulate matter, such as perlite or glass wool. The first stage insulation compartment 10 also includes load bearing internal partitions, bottom panels and top panels 11.

The top panel 11 has two recesses 12, for example substantially inverted I-, L-or T-shaped, for receiving metal supports 16 to which the ends of the strips 22 of the primary sealing membrane 50 are welded.

The groove 12 may have a retaining area 13 over the thickness of the

thermal insulation barrier

51, 53, which extends parallel to the support surface 11. The retaining region 13 extends over the thickness of the

thermal insulation barrier

51, 53 at the end of the recess 12 opposite the support surface 11. The groove 12 then has an L-shaped cross-section, the base of which is formed by the holding area 13.

In the case of a T-shaped metal support 16, the groove 12 has a T-shaped cross section, the base of which is formed by the retaining regions 14 located on either side of the inlet region 13 of the groove 12. The base 17 of the metal support 16 is housed in the holding area 14 to hold the metal support 16 on the thermal insulation barrier in a direction perpendicular to the support surface 11.

In the case of a J-shaped metal support 16, the groove 12 has an I-shaped or L-shaped cross section. The groove 12 may have a retaining area 14, but this is optional. Thus, the groove may have only an inlet area 13. The recess 12 comprises an inverted J-shaped fastener/fastener 26 having a radiused portion 27 complementary to one of the bases 19 of the metal support 16, which is also radiused to be secured in the radiused portion 27 of the fastener 26 to retain the metal support 16 on the thermally insulating barrier in a direction perpendicular to the support surface 11. Advantageously, the groove 12 comprises two fasteners 26 on either side of the groove 12 to hold the base 19 of the first anchoring wing 17 and the base 19 of the second anchoring wing 18.

Fig. 2 to 6 show various embodiments of the metal support 16 anchored in the support surface 11.

Each of the various embodiments may use: a metal support 16, for example as shown in fig. 2, having a base 17 housed in the holding region 14 of the groove 12; or a metal support 16 having circular arc bases 17, each interacting with a complementary circular arc portion 27 of a fastener 26 fixed in the groove 12, as shown for example in fig. 4; or a metal support 16 having circular arc bases 17, each interacting with a complementary circular arc portion 27 of a fastener 26 secured in the retaining region 14 of the groove 12.

Fig. 2 shows an embodiment of a metal support 16 anchored in the support surface 11. In this embodiment, the anchoring

wings

17, 18 of the metal support 16 are welded back to each other such that the base 19 of the anchoring

wings

17, 18 faces away from the other anchoring

wing

18, 17. The anchoring

wings

17, 18 are welded inside the groove 12 using a first stage longitudinal weld 28 and at a distance from the upper portion 21 of the anchoring

wings

17, 18. The first-stage longitudinal weldings 28 are made on the arms 20 of the anchoring

wings

17, 18. The portion of arm 20 above first stage longitudinal weld 28 and upper portion 21 of metal support 16 form a deformable bellows that makes it possible to absorb the forces associated with the thermal shrinkage of the film when metal support 16 forms part of the sealing film.

In the embodiment of fig. 2, the sealing

membranes

50, 52 may be constituted by a plurality of metal supports 16, each placed in a groove 12 in the

thermal insulation barrier

51, 53, so that the metal supports 16 may be welded directly to each other by their adjacent upper portions 21 to form a sealing assembly.

Fig. 3 shows a different embodiment of a metal support 16 anchored in the support surface 11. This embodiment differs from the embodiment of fig. 2 in that the metal supports 16 are not directly welded to each other. Specifically, the sealing

membranes

50, 52 include a plurality of metal strips 22. The metal strips 22 are arranged parallel to each other on the support surface 11. The upper portion 21 of the first anchoring wing 17 is welded to the metal strip 22 by means of a second stage longitudinal weld 29, and the upper portion 21 of the second anchoring wing 18 is welded to the adjacent metal strip 22 by means of a second stage longitudinal weld 29.

Furthermore, each metal strip 22 has, in cross-section, a flat central portion 23 resting on the support surface 11 and at least one offset portion 24 parallel to and at a distance from the support surface 11. The offset portion 24 is located at one end of the flat middle portion 23. Thus, the upper portion 21 of the anchoring

wings

17, 18 is located between the support surface 11 and the offset portion 24. Thus, a second-stage longitudinal weld 29 connecting one of said upper portions 21 and one of said metal strips 22 is made on the offset portion 24 of the metal strip 22. The offset portion 24 then allows the metal strip 22 to overlap the metal support 16.

Fig. 4 and 5 show different embodiments of the metal support 16 anchored in the support surface 11. This embodiment differs from the embodiment of fig. 3 in the shape of the groove, the shape of the base 19 and the connection between the base 19 and the groove 12. In particular, in this embodiment, the sealing

membranes

50, 52 comprise a metal support 16 having circular arc bases 17, each interacting with a complementary circular arc portion 27 of a fastener 26 fixed in the groove 12.

Fig. 6 shows a different embodiment of a metal support 16 anchored in the support surface 11. This embodiment differs from the embodiment of fig. 3 in that the anchoring wings are not fixed to each other by welding and in that the metal strip 22 does not have an offset portion 24. In particular, in this embodiment, the metal support 16 comprises a connecting portion 30 which connects the bases 19 of the anchoring

wings

17, 18 to each other hermetically inside the groove 12. Therefore, it is not necessary to weld the arms of the anchoring wing to each other. Furthermore, the support surface 11 comprises two secondary grooves 15 hollowed out in the thickness direction and extending in the longitudinal direction and closely adjacent to the main grooves 12. Thus, the upper portion 21 of the anchoring wing is located in the second-stage groove 15, so that at least a part of the upper portion 21 passes under the metal strip 22. Thus, in this embodiment, rather than the offset portion 24 allowing the metal strip 22 to overlap the metal support 16, the second stage groove 15.

A thermal insulation layer 25 is placed in the second-stage recess 15 below the upper portion 21 of the anchoring

wings

17, 18. Further, in the embodiment of fig. 6, the main groove 12 includes a flare portion 31 made at an upper end of the main groove 12. The flare portion 31 is formed on the wall of the main groove 12 by chamfering. The flared portion 31 makes it possible to increase the space in which the anchoring

wings

17, 18 can be deformed.

The above described techniques for manufacturing a sealed tank wall may be used in different types of tanks, for example to form a sealed tank wall of an LNG storage tank in an onshore facility or on a floating structure such as an LNG carrier or the like.

Fig. 7 shows another embodiment of a metal support 16 anchored in the support surface 11. This embodiment differs from the embodiment of fig. 3 in that the upper portion 21 of the anchoring

wings

17, 18 is not located between the support surface 11 and the metal strip 22. Specifically, the sealing

membranes

Unlike fig. 3, the metal strip 22 in this embodiment of fig. 7 does not have an offset portion. In this case, the metal strip 22 is substantially flat, so that a portion of the metal strip is located between the support surface 11 and the upper portion 11 of the anchoring

wings

17, 18 after assembly. A second stage longitudinal weld 29 is then made on one end of the upper portion 21 to connect the metal strip 22 to the metal support 16.

During assembly of the sealing barrier of the tank wall, the metal support 16 is inserted into the main groove 12 with the anchoring

wings

17, 18 already welded to each other by the main longitudinal welds 28. Next, the metal strip 22 is then inserted on the support surface 11, below the upper portions 21 of two adjacent metal supports 16, which allows the metal strip 22 to be wedged laterally. The metal strip 22 is then welded to the upper portion 21 of the adjacent metal support by a second stage longitudinal weld 29 to form a sealing membrane.

As shown, the second stage longitudinal welds 29 may be made on or at a distance from the lateral end edges of the upper portion 21.

In embodiments not shown, for example, the embodiments shown in fig. 3, 6 and 7 may be combined. In particular, the metal strip 22 comprises a flat intermediate portion resting on the support surface and an offset portion 23 parallel to the support surface 11 as in fig. 3, but this time in the second-stage groove 15 of fig. 6. The metal support 16 is then placed on the offset portion 23 so that it is located between the upper portion 21 of the anchoring

wings

17, 18 and the bottom of the second-stage groove 15. A second stage longitudinal weld 29 is then made on the upper portion 21 and on the offset portion 23 to connect the metal support 16 to the metal strip 22.

Referring to fig. 8, a view of an LNG carrier 70 with a portion cut away shows a generally prismatic shaped sealed and insulated tank 71 mounted in the double hull 72 of the carrier. The walls of the tank 71 comprise a first stage of sealing barrier intended to be in contact with the LNG contained in the tank; a second stage of sealing barrier arranged between the first stage of sealing barrier and the twin hull 72 of the carrier; and two insulating barriers arranged between the first and second sealing barriers and between the second sealing barrier and the twin hull 72, respectively.

In a manner known per se, a loading/unloading line 73 arranged on the upper deck of the transport vessel may be connected to a marine or harbour terminal by means of suitable connectors for transferring or transferring the LNG cargo from or to the tank 71.

Fig. 8 shows an example of a marine terminal comprising a loading and unloading station 75, a submarine pipeline 76 and an onshore facility 77. The loading and unloading station 75 is a fixed offshore facility comprising a movable arm 74 and a tower 78 supporting the movable arm 74. The movable arm 74 carries a bundle of insulated flexible tubing 79 which can be connected to the loading/unloading line 73. The directable movable arm 74 can be adjusted to accommodate all sizes of LNG carriers. Connecting piping (not shown) extends inside the tower 78. The loading and unloading station 75 allows loading of the LNG carrier 70 from the onshore facility 77 or unloading of the LNG carrier to the onshore facility. The installation comprises a tank 80 for storing liquefied gas and a connecting pipeline 81 connected to a loading or unloading station 75 via a submerged pipeline 76. The underwater pipeline 76 allows transferring liquefied gas between the loading or unloading station 75 and the onshore facility 77 over a longer distance, for example 5km, which makes it possible to keep the LNG carrier 70 at a longer distance from shore during loading and unloading operations.

In order to generate the pressure required for transferring the liquefied gas, use is made of pumps carried on the transport vessel 70 and/or pumps provided with the onshore facility 77 and/or pumps provided with the loading and unloading station 75.

Although the invention has been described in connection with several specific embodiments, it is obvious that the invention is by no means limited to these embodiments, and it is obvious that the invention comprises all technical equivalents of the means described and combinations thereof, if they fall within the scope defined by the claims.

Use of the verb "comprise" or "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims

1. A containment tank wall for storing a fluid, the containment tank wall comprising:

-a support surface (11) extending in a longitudinal direction defined by a length direction of the sealable tank wall and in a transverse direction defined by a width direction of the sealable tank wall, the support surface (11) comprising at least one groove (12) hollowed out in a thickness direction of the sealable tank wall and extending in the longitudinal direction, wherein the longitudinal direction, the transverse direction and the thickness direction form a three-dimensional orthogonal coordinate system;

-a metal sealing membrane (50, 52) carried by the support surface (11) and extending in the longitudinal direction, the metal sealing membrane (50, 52) comprising at least one metal support (16) carried by the support surface (11), the metal support (16) comprising a first anchoring wing (17) and a second anchoring wing (18) sealingly fixed to each other, the first anchoring wing (17) and the second anchoring wing (18) each comprising an upper portion (21) extending in the transverse direction above the support surface (11) and parallel to the support surface (11), such that the upper portion of the first anchoring wing (17) extends on one side of the groove (12) and parallel to the support surface, and the upper portion (21) of the second anchoring wing (18) extends on the other side of the groove (12) and parallel to the support surface, the first anchoring wing (17) and the second anchoring wing (18) each further comprising a base portion (20) held in the thickness direction in the support surface (11) and connected to the respective anchoring wing (19) in the longitudinal direction, the free base portion (21) of the groove (11) and the base (18) comprising a free base portion (20) in the longitudinal direction;

wherein the arms (20) of the first and second anchoring wings (17, 18) are elastically deformable in flexion in the transverse direction to allow the upper portions (21) of the first and second anchoring wings (17, 18) to move in the transverse direction with respect to each other.

2. The containment wall according to claim 1, wherein the first anchoring wing (17) and the second anchoring wing (18) are welded to each other inside the groove (12) by a first stage longitudinal weld (28).

3. The containment tank wall according to claim 1 or 2, wherein the metal support (16) comprises a connecting portion (30) which sealingly connects the bases (19) of the first and second anchoring wings (17, 18) to each other inside the groove (12).

4. The sealing pot wall according to claim 1 or 2, wherein the metal sealing film (50, 52) comprises a plurality of said metal supports (16) arranged parallel to each other, wherein the upper portions (21) of the first and second anchoring wings (17, 18) of two adjacent metal supports (16) are connected in a sealing manner directly or indirectly.

5. Sealed tank wall according to claim 4, wherein the metallic sealing film (50, 52) comprises a metal strip (22) resting on and parallel to the support surface (11), said metal strip (22) being arranged parallel to the metal support (16), and wherein a first edge of said metal strip (22) is welded by a first and second stage longitudinal weld (29) to the upper portion (21) of a first anchoring wing (17) of a first one of said metal supports, and a second edge of said metal strip (22) is welded by a second and second stage longitudinal weld (29) to the upper portion (21) of a second anchoring wing (18) of a second one of said metal supports.

6. The sealed tank wall according to claim 5, wherein one end of the metal strip is located between the support surface (11) and an upper portion (21) of one of the first and second anchoring wings (17, 18), and wherein the second stage longitudinal weld (29) is made on the upper portion (21) to connect the metal strip (22) to the upper portion (21).

7. The sealed tank wall of claim 5, wherein the cross section of the metal strip (22) comprises: -a flat intermediate portion (23) resting on the support surface (11) and-at least one offset portion (24) parallel to the support surface (11) and at a distance therefrom, -an upper portion (21) of one of the first and second anchoring wings (17, 18) being located between the support surface (11) and the offset portion (24), and wherein the second-stage longitudinal weld (29) connecting the upper portion (21) and an edge of the metal strip (22) is made on the offset portion (24) of the metal strip (22).

8. The sealed tank wall according to claim 5, wherein the groove (12) is a main groove (12) and the support surface (11) comprises at least one second-stage groove (15) dug out in the thickness direction and extending in the longitudinal direction and close to the main groove (12), and wherein an upper portion (21) of one of the first and second anchoring wings is located in the second-stage groove (15) and below a metal strip (22).

9. The sealable tank wall of claim 1 or 2, wherein the groove (12) has an inlet region (13) extending in the thickness direction, the groove (12) comprising a retaining region (14) arranged below the inlet region (13) and extending parallel to the support surface (11) over a width greater than the inlet region (13), and wherein a base (19) of at least one anchoring wing of the metal support (16) is accommodated in the retaining region (14).

10. The sealed tank wall according to claim 1 or 2, wherein the groove (12) comprises at least one fastener (26), the fastener (26) being configured to retain one of the bases (19) of the metal support (16) in the groove (12).

11. The sealed tank wall according to claim 10, wherein at least one of the bases (19) of the metal support (16) has a circular arc shape and the fastening member (26) has a complementary circular arc portion (27), so that the bases (19) of the metal support (16) and the circular arc portions (27) of the fastening member (26) fit one inside the other.

12. The sealable tank wall of claim 1 or 2, wherein the sealable tank wall comprises a thermal insulation barrier (51, 53) comprising a top panel comprising the support surface (6, 11).

13. The sealed tank wall of claim 12, wherein the thermal insulation barrier is a primary thermal insulation barrier (51) and the sealing membrane is a primary sealing membrane (50), and wherein the sealed tank wall comprises a secondary thermal insulation barrier (53) and a secondary sealing membrane (52) arranged below the primary thermal insulation barrier (51).

14. A polyhedral sealed can (71) comprising a plurality of can walls sealingly secured to each other to form a polyhedral internal space for storing fluid, wherein one of the can walls is a can wall according to claim 1 or 2.

15. A transport vessel (70) for transporting liquid products, comprising a hull (72) and a seal pot (71) according to claim 14 arranged in the hull.

16. A method of loading or unloading a carrier vessel (70) according to claim 15, wherein liquid product is transferred from or from a floating or on-shore storage facility (77) to the seal pot (71) of the carrier vessel via insulated pipelines (73, 79, 76, 81).

17. A transfer system for transferring a liquid product, the system comprising: a carrier vessel (70) according to claim 15; an insulated line (73, 79, 76, 81) arranged to connect a seal pot (71) installed in the hull of the carrier vessel to a floating or onshore storage facility (77); and a pump for pumping a stream of liquid product from the floating or on-shore storage facility to the sealpot of the transport vessel or from the sealpot of the transport vessel to the floating or on-shore storage facility through the insulated pipeline.