EP3940287A1 - Sealed and thermally insulating vessel comprising a metal membrane corrugated according to orthogonal folds - Google Patents

Abstract

Sealed and thermally insulating tank integrated into a support structure, the tank wall comprising:-a thermal insulation barrier retained on the support wall and consisting of insulation blocks (1,13) juxtaposed in parallel rows and separated from each other from the others by interstices (10),-a sealing barrier supported by the thermal insulation barrier and made up of welded metal sheets (11,15). , two metal connecting strips (5,6 and 14a,14b), arranged parallel to the sides of the insulation block. On the strips are welded the sheets (11,15) of the membrane supported by the insulation block. The connecting strips are integral with the insulation block which carries them, The sheets (11,15) each comprise at least two orthogonal folds (12a, 12b, 16a, 16b) parallel to the sides of the insulation blocks (1,13 ), said plies being inserted into the interstices (10) provided between the insulation blocks.

Description

The present invention relates to a sealed and thermally insulating tank; in particular, the present invention relates to tanks intended to contain cold liquids, for example tanks for the storage and/or transport by sea of liquefied gases.

Sealed and thermally insulating tanks can be used in different industries to store hot or cold products. For example, in the field of energy, liquefied natural gas (LNG) is a liquid which can be stored at atmospheric pressure at around -163°C in storage tanks on land or in tanks on board floating structures. .

Such a tank is for example described in the document FR-A-2724623 .

• une barrière d'isolation thermique retenue sur la paroi porteuse et constituée de blocs d'isolation en forme de parallélépipèdes rectangles, juxtaposés selon des rangées parallèles et séparés les uns des autres par des interstices,
• une barrière d'étanchéité supportée par la barrière d'isolation thermique, ladite barrière d'étanchéité comportant une membrane métallique constituée de tôles métalliques soudées les unes aux autres de manière étanche,
• chaque bloc d'isolation d'une barrière d'isolation thermique portant, sur sa face opposée à la paroi porteuse, au moins deux bandes de liaison métalliques sensiblement orthogonales, disposées parallèlement aux côtés du bloc d'isolation, bandes sur lesquelles sont soudées les tôles de la membrane métallique supportée par ledit bloc d'isolation, lesdites bandes de liaison étant solidaires du bloc d'isolation qui les porte,
• une pluralité des tôles de la membrane métallique comportant chacune au moins deux plis orthogonaux parallèles aux côtés des blocs d'isolation thermique, lesdits plis étant insérés dans les interstices ménagés entre les blocs d'isolation.

According to one embodiment, the invention provides a sealed and thermally insulating tank integrated in a structure which comprises a supporting wall, said tank comprising a tank wall fixed to said supporting wall, the tank wall comprising:

• a thermal insulation barrier retained on the load-bearing wall and consisting of insulation blocks in the form of rectangular parallelepipeds, juxtaposed in parallel rows and separated from each other by interstices,
• a sealing barrier supported by the thermal insulation barrier, said sealing barrier comprising a metal membrane consisting of metal sheets welded to each other in a sealed manner,
• each insulation block of a thermal insulation barrier carrying, on its face opposite the load-bearing wall, at least two substantially orthogonal metal connecting strips, arranged parallel to the sides of the insulation block, strips to which the sheets of the metal membrane supported by said insulation block, said connecting strips being integral with the insulation block which carries them,
• a plurality of sheets of the metal membrane each comprising at least two orthogonal plies parallel to the sides of the thermal insulation blocks, said plies being inserted into the interstices provided between the insulation blocks.

According to embodiments, such a tank may comprise one or more of the following characteristics.

According to one embodiment, the sheets of the metal membrane each comprise at least two orthogonal folds parallel to the sides of the thermal insulation blocks, inserted into the interstices made between the insulation blocks.

According to one embodiment, the vessel wall comprises a primary element and a secondary element disposed between the carrier wall and the primary element, each of the primary and secondary elements including a thermal insulation barrier consisting of insulation blocks in the form of rectangular parallelepipeds, juxtaposed in parallel rows and a sealing barrier arranged on the thermal insulation barrier, the thermal insulation barrier of the secondary element being secured to the load-bearing wall, the thermal insulation barrier of the primary element being secured by hooking means linked to the thermal insulation barrier of the secondary element.

According to one embodiment, the sealing barrier of the secondary element consists of the metallic membrane comprising a plurality of sheets each comprising at least two orthogonal plies parallel to the sides of the thermal insulation blocks, and inserted into the interstices formed between the insulation blocks of the secondary element.

According to one embodiment, the sheets of the metal membrane of the secondary element are made of an alloy of iron with nickel or manganese and having a coefficient of expansion less than or equal to 7.10 ^-6 K ^-1.

According to one embodiment, the plies of the metal sheets of the secondary sealing barrier are inserted into the interstices between the insulation blocks of the thermal insulation barrier of the secondary element.

According to one embodiment, the folds of the metal sheets of the primary sealing barrier are inserted into the interstices between the insulation blocks of the thermal insulation barrier of the primary element. According to other embodiments, the primary membrane can have a different design from the secondary membrane, for example with projecting folds towards the inside of the tank. In other words, the sealing barrier of the primary element consists of metal sheets welded to each other in a sealed manner and comprising folds directed towards the interior of the vessel.

According to one embodiment, an insulation block of the thermal insulation barrier comprises a bottom plate on which is placed a layer of foam, in particular of polyurethane, the bottom plate projecting beyond the foam. The plates can be made of plywood. The secondary element is held in contact with the load-bearing wall by means of fasteners welded to the load-bearing wall and cooperating with the projecting zones of the plates of the insulation block, possibly with interposition of resin beads to compensate for local imperfections in the load-bearing wall.

According to one embodiment, an insulating block of the thermal insulation barrier of the secondary element is held on the load-bearing wall by gluing.

Numerous arrangements of the connecting strips on the insulation blocks are possible, in particular as regards the position and the number of the connecting strips on an insulation block. In this respect, not all insulation blocks are necessarily identical.

According to one embodiment, the connecting strips of each block of insulation of the thermal insulation barrier of the secondary element carries two connecting strips which are arranged along the two axes of symmetry of the rectangle defined by a large face of said insulation block.

According to one embodiment, the connecting strips of each insulation block of the thermal insulation barrier of the primary element are arranged near the edges of a large face of said insulation block.

According to one embodiment, an insulation block comprises three connecting strips arranged on the cover plate.

According to one embodiment, the connecting strips of an insulation block are housed in recesses made in the plate or the layer of foam which carries it so as not to form an extra thickness on the corresponding face of the insulation block.

According to one embodiment, a connecting strip of an insulation block is fixed in its recess by screwing, stapling, riveting or gluing.

According to one embodiment, the attachment means of the thermal insulation barrier of the primary element comprise a continuous metal plate arranged at the intersection of the two bands connecting each block of insulation of the secondary element, and a projecting member passing through the level of the sealing barrier of the secondary element without rising to the level of the sealing barrier of the primary element.

According to one embodiment, the metal sheets adjacent to the sealing barriers of the primary and secondary elements are overlap welded in line with the connection strips carried respectively by the thermal insulation barriers of the primary and secondary elements.

According to one embodiment, the projecting members are studs, the base of which is fixed to the continuous metal plate of the isolation block of the secondary element, an intermediate piece being interposed between, on the one hand, a nut cooperating with the thread provided at the free end of the stud and, on the other hand, the overhanging parts of the plates of the insulation blocks of the thermal insulation barrier of the primary element. The base of the studs is fixed by welding and/or screwing to the continuous metal plate of the secondary element insulation block.

According to one embodiment, the sheets of the metal membranes, which constitute the sealing barrier, are rectangular and each comprise two folds arranged along the axes of symmetry of the rectangle formed by their edges.

According to one embodiment, the two plies of a sheet and the sealing barrier of the primary element intersect at the center of the rectangular sheet.

According to one embodiment, one of the plies of a sheet is continuous and the other is interrupted in its central part.

According to one embodiment, sheets of a first type have a continuous fold on their major axis.

According to one embodiment, sheets of a second type have a discontinuous fold on their long axis.

According to one embodiment, on a vessel wall the sheets of the first and second types are regularly alternated so that a sheet of one of the types is always adjacent to a sheet of the other type.

According to one embodiment, each insulation block of the thermal insulation barrier comprises two series of orthogonal slots, each of said series comprising slots arranged parallel to two opposite sides of the insulation block, and the sheets of the metal membrane each comprise two series of additional folds, each of said series of additional folds comprising folds, orthogonal to the folds of the other series, parallel to one of the two folds inserted in the interstices, and inserted into the slots of one of the series of slots in the insulation block.

According to another embodiment, the metal membrane comprises a second plurality of sheets, each of the sheets of the second plurality comprising a single ply parallel to two opposite sides of the insulation blocks, said ply being inserted in a gap provided between two blocks insulation.

According to another embodiment, each insulation block of the thermal insulation barrier comprises a slot parallel to two opposite sides of the insulation blocks and in which the metal membrane comprises a second plurality of sheets, each of the sheets of the second plurality comprising a ply inserted in a slot provided in an insulation block and a ply inserted in a gap provided between two insulation blocks.

Such a tank can be part of an onshore storage facility, for example to store LNG or be installed in a floating structure, coastal or deep water, including an LNG carrier, a floating storage and regasification unit (FSRU), a floating production and remote storage unit (FPSO) and others.

According to one embodiment, a vessel for the transport of a cold liquid product comprises a double hull and a aforementioned tank placed in the double hull.

According to one embodiment, the invention also provides a method for loading or unloading such a ship, in which a cold liquid product is conveyed through insulated pipes from or to a floating or terrestrial storage installation to or from the ship's tank.

According to one embodiment, the invention also provides a transfer system for a cold liquid product, the system comprising the aforementioned vessel, insulated pipes arranged so as to connect the tank installed in the hull of the vessel to a floating storage installation or land and a pump to cause a flow of cold liquid product through the insulated pipes from or to the floating or land storage facility to or from the tank of the ship.

One idea underlying the invention is to provide a waterproof and insulating multilayer structure which is easy to produce over large surfaces. Certain aspects of the invention are based on the idea of producing insulation blocks whose geometry is simple and whose manufacture is inexpensive. Certain aspects of the invention start from the idea of providing a waterproof membrane, in particular secondary membrane made of sheet steel with a low coefficient of expansion, for example Invar ^® or other, of low thickness, in particular less than or equal to 0.7 mm, thus making it possible to obtain a low stiffness allowing anchoring at the edges of the vessel wall using relatively compact anchoring means.

The invention will be better understood and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely by way of demonstration and not limitation, with reference to the accompanying drawings.

• La figure 1 représente schématiquement, en perspective, un assemblage de différents organes constituant une cuve étanche et thermiquement isolante selon l'invention : cette vue générale comporte des parties arrachées pour permettre de voir les barrières d'isolation thermique et d'étanchéité des éléments secondaire et primaire de la paroi de cuve ;
• -la figure 2 représente schématiquement une coupe d'une paroi de cuve selon l'invention, dont la barrière d'étanchéité primaire comporte des plis saillants du côté opposé à la paroi porteuse ;
• -la figure 3 représente, en perspective, un bloc d'isolation de la barrière d'isolation thermique de l'élément secondaire de paroi de la cuve de la figure 1, ledit bloc comportant, dans sa zone centrale, un moyen d'accrochage des blocs d'isolation de la barrière d'isolation thermique de l'élément primaire de la paroi de la cuve ;
• -la figure 4 représente, en perspective, un bloc d'isolation de la barrière d'isolation thermique de l'élément primaire de la paroi de cuve de la figure 1 ;
• -la figure 5 représente, en perspective écorchée, les parties constitutives des barrières d'isolation thermique et d'étanchéité des éléments primaire et secondaire d'une paroi de cuve selon l'invention comportant, dans sa barrière d'étanchéité de l'élément primaire, des plis saillants vers l'intérieur de la cuve comme représenté sur la figure 2, ladite figure 5 montrant en détail la réalisation d'un moyen d'accrochage de la barrière isolante primaire sur une bande de liaison de la barrière isolante secondaire ;
• -la figure 6 représente une vue analogue à la figure 5, dans laquelle deux parties d'un moyen d'accrochage sont représentées désolidarisées, en perspective éclatée ;
• -la figure 7 représente schématiquement en coupe un moyen d'accrochage selon un autre mode de réalisation que celui des figures 5 et 6 ;
• -la figure 8 représente une vue de dessus en plan du moyen d'accrochage de la figure 7 ;
• -la figure 9 représente un schéma d'assemblage, dans une paroi de cuve, des tôles constitutives d'une barrière d'étanchéité, les tôles étant d'un premier et d'un deuxième type, pour que la souplesse de la membrane métallique de la barrière d'étanchéité soit relativement uniforme ;
• -la figure 10 représente un schéma d'assemblage analogue à celui de la figure 9, pour une variante de réalisation dans laquelle les plis des tôles métalliques de la barrière d'étanchéité qui sont disposés selon une première direction soient sensiblement alignés d'une tôle de la paroi de cuve à une tôle adjacente, alors que dans la direction orthogonale à la première, les plis sont interrompus pour éviter un croisement de plis ;
• -la figure 11 représente, en perspective schématique, un tronçon de cuve polyédrique réalisé dans un navire transporteur de GNL utilisant la membrane d'étanchéité représentée sur la figure 10, ce qui permet d'améliorer la souplesse de la membrane d'étanchéité pour des déformations de l'axe du navire au cours d'un transport maritime ;
• -la figure 12 représente schématiquement deux autres variantes de tôles métalliques utilisables pour former une membrane d'étanchéité ;
• -la figure 13 est une représentation schématique écorchée d'une cuve de navire méthanier et d'un terminal de chargement/déchargement de cette cuve ;
• -les figures 14 à 16 représentent schématiquement encore d'autres variantes de tôles métalliques utilisables pour former une membrane d'étanchéité ;
• -la figure 17 représente schématiquement dix-sept modes de réalisation de tôles métalliques plissées utilisables pour former une membrane d'étanchéité ;
• -les figures 18 à 23 représentent schématiquement différents agencements des tôles métalliques plissées de la figure 17 pouvant être répétés de manière périodique pour réaliser des membranes d'étanchéité.
• - la figure 24 représente, en perspective, un bloc d'isolation de la barrière d'isolation thermique de l'élément secondaire, selon un autre mode de réalisation.
• - la figure 25 illustre en perspective les barrières d'isolation thermique et d'étanchéité de l'élément secondaire selon le mode de réalisation de la figure 25, la barrière d'étanchéité étant représentée partiellement arrachée.
• - la figure 26 est une représentation une coupe des barrières d'isolation thermique et d'étanchéité de l'élément secondaire selon le mode de réalisation des figures 24 et 25.
• - la figure 27 illustre un schéma d'assemblage, dans une paroi de cuve, des tôles constitutives d'une barrière d'étanchéité secondaire, selon un autre mode de réalisation.
• - la figure 28 illustre un schéma d'assemblage, dans une paroi de cuves, de tôles constitutives d'une barrière d'étanchéité secondaire, selon encore un autre mode de réalisation.

In these drawings:

• The figure 1 schematically represents, in perspective, an assembly of various components constituting a sealed and thermally insulating tank according to the invention: this general view includes parts torn away to allow seeing the thermal insulation and sealing barriers of the secondary and primary elements of the the vessel wall;
• -the figure 2 schematically shows a section of a vessel wall according to the invention, the primary sealing barrier of which comprises projecting folds on the side opposite the load-bearing wall;
• -the picture 3 shows, in perspective, an insulation block of the thermal insulation barrier of the secondary wall element of the vessel of the figure 1 , said block comprising, in its central zone, a means for attaching the insulation blocks of the thermal insulation barrier of the primary element of the wall of the vessel;
• -the figure 4 shows, in perspective, an insulation block of the thermal insulation barrier of the primary element of the vessel wall of the figure 1 ;
• -the figure 5 shows, in cutaway perspective, the constituent parts of the thermal insulation and sealing barriers of the primary and secondary elements of a vessel wall according to the invention comprising, in its sealing barrier of the primary element, folds protruding towards the inside of the tank as shown in the face 2 , said figure 5 showing in detail the production of a means for attaching the primary insulating barrier to a connecting strip of the secondary insulating barrier;
• -the figure 6 represents a view similar to the figure 5 , in which two parts of a hooking means are shown separated, in exploded perspective;
• -the figure 7 schematically shows in section a means of attachment according to another embodiment than that of figure 5 and 6 ;
• -the figure 8 shows a top plan view of the attachment means of the figure 7 ;
• -the figure 9 shows an assembly diagram, in a vessel wall, of the sheets constituting a sealing barrier, the sheets being of a first and a second type, so that the flexibility of the metal membrane of the barrier sealing is relatively uniform;
• -the figure 10 shows an assembly diagram similar to that of the figure 9 , for a variant embodiment in which the folds of the metal sheets of the sealing barrier which are arranged in a first direction are substantially aligned from one sheet of the vessel wall to an adjacent sheet, whereas in the direction orthogonal to the first, the folds are interrupted to avoid a crossing of folds;
• -the figure 11 shows, in schematic perspective, a section of polyhedral tank made in an LNG carrier ship using the sealing membrane shown in the figure 10 , which makes it possible to improve the flexibility of the sealing membrane for deformations of the axis of the ship during maritime transport;
• -the figure 12 schematically represents two other variants of metal sheets that can be used to form a waterproofing membrane;
• -the figure 13 is a cutaway diagrammatic representation of an LNG carrier tank and a loading/unloading terminal for this tank;
• -the figures 14 to 16 schematically represent still other variants of metal sheets that can be used to form a sealing membrane;
• -the figure 17 schematically represents seventeen embodiments of pleated metal sheets that can be used to form a waterproofing membrane;
• -the figures 18 to 23 schematically represent different arrangements of the pleated metal sheets of the figure 17 that can be repeated periodically to produce waterproofing membranes.
• - the figure 24 represents, in perspective, an insulating block of the thermal insulation barrier of the secondary element, according to another embodiment.
• - the figure 25 illustrates in perspective the thermal insulation and sealing barriers of the secondary element according to the embodiment of the figure 25 , the sealing barrier being shown partially broken away.
• - the figure 26 is a cross-sectional representation of the thermal insulation and sealing barriers of the secondary element according to the embodiment of the figures 24 and 25 .
• - the figure 27 illustrates an assembly diagram, in a vessel wall, of the sheets making up a secondary sealing barrier, according to another embodiment.
• - the figure 28 illustrates an assembly diagram, in a vessel wall, of sheets constituting a secondary sealing barrier, according to yet another embodiment.

In the different variants represented in the drawings, the components, which play the same role, have been designated by the same reference numbers even if their realization has been somewhat modified.

Referring to the drawings, it can be seen that an insulating block of the thermal insulation barrier of the secondary element of a vessel wall has been designated by 1 as a whole. This block has a length L and a width l, for example, 3 m and 1 m respectively; it has the shape of a rectangular parallelepiped and is made of polyurethane foam between two plywood plates. One of the plates 2 a projects beyond the periphery of the foam and is intended to bear against the bearing wall 3 with the interposition of resin beads 4 enabling local faults of the bearing wall 3 to be corrected. The other plate 2 b of the insulation block 1 comprises, along its two axes of symmetry, a metal connecting strip 6, which is placed in a recess 7 and which is fixed there by screws, rivets, staples or glue. In the crossing zone of the strips 5 and 6, a continuous metal plate has been arranged, which supports, in the center of the crossing of the strips, a stud 8 projecting above the plate 2b . The plate 2 a is maintained on the supporting wall 3 by glueing by means of the resin rods 4 and 9 by studs welded to the supporting wall 3. It is ensured that between two adjacent blocks 1, be formed a gap 10, for example due to the presence of the protruding portions of the plate 2a, but optionally, by means of positioning pins.

If we now return to the figure 1 , it can be seen that, starting from the uncovered secondary insulating block represented at the top and left of the figure and going in an oblique direction to the right and downwards, the perspective shows a secondary insulating block 1, which is partially covered a sheet 11 constituting part of the secondary sealing barrier of the vessel wall. This metal sheet 11 has a substantially rectangular shape and it comprises, along each of the two axes of symmetry of this rectangle, a fold 12 a , respectively 12 b . The plies 12 a and 12 b form reliefs arranged in the direction of the supporting wall 3 and they are housed in the interstices 10 of the secondary insulating barrier. The metal sheets 11 are made of Invar ^®, whose thermal expansion coefficient is typically between 1.5x10 ^-6 and 2.10 ^-6 K ^-1. They have a thickness of between approximately 0.7 mm and approximately 0.4 mm. Two adjacent sheets 11 are overlap welded together, as will be described on the figure 5 and 6 . The retaining of the sheets 11 on the insulating blocks 1 is carried out with the strips 5 and 6 on which are welded at least two edges of the sheets 11.

According to a preferred embodiment, the metal sheets 11 are made of a manganese-based alloy having a coefficient of thermal expansion substantially equal to 7.10 ^-6 K ^-1 . Such an alloy is generally less expensive than alloys with a high nickel content such as invar ^® .

Referring again to the figure 1 , starting from the area where the metal sheets 11 of the sealing barrier of the secondary element of the vessel wall and moving obliquely to the right and downwards, it can be seen that a area where the secondary sealing barrier is covered with an insulation block 13 of the thermal insulation barrier of the primary element of the vessel wall. The isolation block 13 is shown in detail in the figure 4 . It can be seen that this block has a general structure, which is similar to that of block 1, that is to say that it is a sandwich made up of a polyurethane foam between two plywood plates. The bottom plate 13a, which rests on a metal sheet 11, has overhanging parts 30 at the four corners. The fixing of said insulating blocks 13 is carried out through the projecting parts 30 and the pins 8. On the upper face of the insulating block 13, there are two connecting strips 14 a, 14 b; these connecting strips are metallic and arranged in recesses made in the insulating block 13 to avoid any excess thickness on this insulating block. The two strips 14 a, 14 b are arranged parallel to edges of the box 13 and are secured in their recesses as was previously described for the bands 5 and 6.

Finally, the figure 1 shows, when moving from an element 13 obliquely downwards and to the right, the placement of a metal sheet 15 constituting the sealing barrier of the primary element of the vessel. This sheet 15 can be made of stainless steel with a thickness of approximately 1.2 mm; it comprises folds arranged along axes of symmetry of the rectangle that it constitutes, as has already been indicated for the metal sheets 11. These folds can be in relief on the side of the bearing wall 3, but they can also be in relief towards the inside of the tank; these folds have been designated by 16, 16b. On the picture 2 , as well as on the figure 5 and 6 , the folds 16 a , 16 b are directed towards the inside of the tank.

On the figure 5 and 6 , there is shown an embodiment in which the metal sheets 11 have a fold 12 a arranged inside a gap 10 and shown in dotted lines. The adjacent sheets of the secondary sealing barrier are overlap welded, the weld zone being designated by 17. The weld is made on the connecting strip 6, which also carries studs 18 welded at their base to strip 6 and threaded at their upper end to cooperate with a clamping bolt 19. This clamping bolt is placed at the bottom of a cup, the peripheral edge 20 rests in a recess 21 made on the plywood plate 13b, which limits the primary insulation barrier 13 towards the inside of the tank. On the primary insulating block is arranged a sheet 15, which has two lines of folds in relief towards the inside of the tank, the orthogonal folds meeting to form nodes; the sheets 15 are welded in a sealed manner and form the primary sealing barrier of the tank.

The connecting strip 6 is continuous at the level of the intersection with the connecting strip 5 so as to form a sealed zone 39 on which the corners of four sheets 11 can be welded around the stud 18. Thus, it is not necessary to perforate a sheet 11 to allow the stud 18 to pass in the direction of the primary element of the vessel wall. Over the rest of their length, the connecting strips 5 and 6 are preferably formed of discontinuous juxtaposed segments, in order to limit the stresses resulting from thermal contraction, in particular the stresses in the welds with the sheets 11.

The figures 7 and 8 represent a variant of the hooking means, which make it possible to retain insulation blocks 13 of the primary thermal insulating barrier bearing against the metal membrane 11 of the secondary sealing barrier. This attachment means comprises a stud 18, the base of which is secured to the plywood plate 2b of the secondary thermal insulation block 1. Between the nut 22 and the projecting parts 30 of the plywood plates of the primary insulating blocks 13, an elastic spacer 23 has been interposed. This therefore ensures the maintenance of the insulating blocks 13 of the primary thermal insulation barrier of the tank on the secondary element of the tank without the stud 18 coming at the level of the metal sheets 15 of the primary sealing barrier.

In the figures, in particular the picture 2 , relaxation slots 40 are shown through approximately half the thickness of the insulating blocks from the cover plate. These relaxation slots have the effect of subdividing the cover plates 2b and 13b into separate portions. However, such relaxation slots are not always necessary, depending on the properties of the material used to produce the insulating blocks and the thermal stresses applied to them. In an embodiment not shown, an insulating block 1 or 13 has no relaxation slot, so that the cover plate 2b or 13b is continuous.

The figures 9 to 12 relate to the relative arrangements of the folds that have been provided in the metal sheets of the secondary sealing barrier. These arrangements can also be used for the primary membrane.

The figure 9 represents the case where sheets are used comprising a continuous ply and a discontinuous ply orthogonal to the continuous ply. Two types of sheets 31 and 32 are arranged alternately. The edges of the sheets 31 and 32 are shown in broken lines. The folds are shown in continuous lines. It can be seen that a membrane is obtained characterized by the regularity of the flexibility in the two directions.

On the contrary, for the figure 10 , it is proposed to use only the type of sheet 32 that all the folds in one direction are continuous folds, while the folds in the other direction are discontinuous folds. On the figure 11 , we see that for a tank intended to equip a ship, we make sure that the discontinuous folds are parallel to the axis of the ship and the continuous folds, perpendicular to this axis because, during transport, the deformation of the hull of the ship takes place mainly by deformation of the axis of the ship in a vertical plane due to pitching.

The figure 12 shows two other sheets 51 and 52 that can be used to make the watertight barrier at the level of the bulkheads transverse to the axis of the ship, as sketched on the figure 11 .

The figures 14 and 15 represent pleated sheets H and F that can be used instead of sheets 51 and 52 of the figure 11 to form the sealing barrier at the level of the bulkheads transverse to the axis of the ship. In this case, one obtains lines of undulations which are continuous in the width of the tank, and no longer in its height.

The figure 16 represents a pleated sheet E usable alone or in combination with the previous embodiments to form sealing barriers.

The figure 17 represents various pleated sheets A to R, including the examples given above and other examples, which can be used alone or can be combined in many ways to form sealing barriers.

The pleated sheets A to R each time have simple folds or simple undulations, which facilitates their assembly by tight welds. They can be combined according to multiple arrangements making it possible each time to obtain a certain elongation of the metal membrane in the two directions of the plane. Preferred arrangements are shown in the figures 18 to 23 .

In a variant not shown, an alternation of two types of sheets is made similar to the figures 22 and 23 , but this time with sheets H and I of the figure 17 .

In one embodiment illustrated in the figures 24, 25 and 26 , the insulation block 1 of the thermal insulation barrier of the element secondary has two series of slots 53 a , 53 b orthogonal. Each series of slots 53 a, 53 b is parallel to two opposite sides of the insulation block 1. Each insulating block 1 here includes two slots 53a extending in its longitudinal direction and eight slots 53b extending transversely to its longitudinal direction. The slots 53a extend over the entire length of the insulation block 1 and the slots 53b extend over its entire width. Therefore, the connecting strips 5, 6 on which the edges of the sheets 11 of the secondary sealing barrier are welded are here produced discontinuously.

Furthermore, as shown in the figure 25 , the metal sheets 11 of the secondary sealing barrier comprise two series of folds 12a, 12b, 12c, 12d. Each of the series has folds that are perpendicular to the folds of the other series. In addition, each series comprises one of the orthogonal plies 12a, 12b, housed in the interstices 10 provided between the insulation blocks 1, and a plurality of additional plies 12c, 12d which are parallel to said fold 12a, 12b. Additional folds 12c, 12d are identical with the folds 12 a and 12 b and form reliefs in the direction of the supporting wall 3. Additional folds are inserted into the slots 53a, 53b formed in the insulating block 1. Such a mode embodiment makes it possible to further increase the flexibility of the secondary sealing barrier.

On the figure 27 , the folds 12 a , 12 b of the plates 11 of the metal membrane of the secondary element are shown in dotted lines. Furthermore, the position of an insulation block 1 of the secondary thermal insulation barrier 10 is represented, by transparency. The position of an insulation block 13 of the primary thermal insulation barrier attached to the insulation blocks 1 of the secondary thermal insulation barrier 10 is also shown. In this embodiment, the primary sealing barrier comprises more than sheets 11 than insulation blocks 1. The primary sealing barrier here comprises twice as many sheets 11 as insulation blocks 11. The sheets 11 therefore have a length substantially equal to that of the insulation blocks 1 and a width which is substantially equal to half that of the insulation blocks. Thus, part of the sheets 11 is lap welded to four adjacent insulation blocks 1. The other part of the sheets 11 is overlap welded on only two adjacent insulation blocks 1. In order to ensure the fixing of the sheets on the insulation blocks 1, these comprise three connecting strips 5a, 5b, 6. The connecting strip 5a is oriented transversely to the insulation block 1. The connecting strips 5a , 5b are arranged in the longitudinal direction of the insulation block 1.

The sheets 11 lap-welded to four adjacent insulation blocks 1 each comprise two orthogonal plies 12 a , 12 b inserted into the interstices 10 provided between the insulation blocks 1. The lap-welded sheets 11 to two insulation blocks 1 adjacent each have only a single ply 12b inserted between the two adjacent insulation blocks 1 between which it extends.

At the center of the intersections between the connecting strip 6 and the connecting strips 5a, 5b, the insulation blocks 1 include a stud 18 projecting towards the inside of the tank and allowing the insulation blocks 13 to be attached to the primary thermal insulation barrier.

The embodiment illustrated in the figure 28 is substantially similar to that of figure 27 . However, in this embodiment, the sheets 11 are identical and each comprise two orthogonal folds 12a, 12b. Therefore, the insulation blocks 1 have a median slot 53 e extending along their longitudinal direction. The median slots 53e make it possible to accommodate the folds 12a extending in the longitudinal direction of the lap welded sheets 11 on two adjacent insulation blocks 1.

Still other variations of corrugated sheets and other combinations can be designed by making changes to various characteristics, including corrugation spacing, number of corrugations per sheet, discontinuous corrugation length (number of pitches), the shape of the intersections between the corrugations, namely secant or non-secant intersection, the orientation of the continuous corrugations, namely longitudinal or transverse orientation, and the orientation of the sheets themselves, namely horizontal orientation or vertical orientation (90° rotation), and combinations of such modifications.

The tanks described above can be used in different types of installations such as installations on land or in a floating structure such as an LNG carrier or other.

With reference to the figure 13 , a cutaway view of an LNG carrier 70 shows a sealed and insulated tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary tight barrier intended to be in contact with the LNG contained in the tank, a secondary tight barrier arranged between the primary tight barrier and the double hull of the ship, and two thermally insulating barriers arranged respectively between the primary waterproof barrier and the secondary waterproof barrier, and between the secondary waterproof barrier and the double hull 72.

In a manner known per se, loading/unloading pipes arranged on the upper deck of the ship can be connected, by means of suitable connectors, to a maritime or port terminal to transfer a cargo of LNG from or to the tank 71.

The figure 13 represents an example of a maritime terminal comprising a loading and unloading station 75, an underwater pipeline 76 and an installation on land 77. The loading and unloading station 75 is a fixed offshore installation comprising a mobile arm 74 and a tower 78 which supports the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading/unloading pipes 73. The orientable mobile arm 74 adapts to all sizes of LNG carriers. A connecting pipe, not shown, extends inside the tower 78. The loading and unloading station 75 allows the loading and unloading of the LNG carrier 70 from or to the shore installation 77. This comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the underwater pipe 76 to the loading or unloading station 75. The underwater pipe 76 allows the transfer of the liquefied gas between the loading or unloading station 75 and the shore installation 77 over a great distance, for example 5 km, which makes it possible to keep the LNG carrier 70 at a great distance from the coast during loading and unloading operations.

To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and/or pumps fitted to the shore installation 77 and/or pumps fitted to the loading and unloading station 75 are used.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

The use of the verb "to comprise", "to understand" or "to include" and of its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim. The use of the indefinite article “un” or “une” for an element or a step does not exclude, unless otherwise stated, the presence of a plurality of such elements or steps.

In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims (27)

Sealed and thermally insulating tank integrated in a structure which comprises a supporting wall, said tank comprising a tank wall fixed on said supporting wall (3), the tank wall comprising: - a thermal insulation barrier retained on the load-bearing wall (3) and consisting of insulation blocks (1) in the form of rectangular parallelepipeds, juxtaposed in parallel rows and separated from each other by interstices (10), - a sealing barrier supported by the thermal insulation barrier, said sealing barrier comprising a metal membrane made up of metal sheets (11) welded to each other in a sealed manner, - each insulation block of the thermal insulation barrier bearing, on its face opposite the load-bearing wall (3), at least two substantially orthogonal metal connecting strips (5,6), arranged parallel to the sides of the insulation, strips on which the sheets (11) of the metal membrane supported by the said insulation block are welded, the said connecting strips being integral with the insulation block which carries them, - a plurality of sheets (11) of the metal membrane each comprising at least two orthogonal plies (12a, 12 b ) parallel to the sides of the thermal insulation blocks (1), said plies being inserted into the interstices (10) formed between insulation blocks. Vessel according to Claim 1, in which the vessel wall comprises a primary element and a secondary element disposed between the load-bearing wall and the primary element, each of the primary and secondary elements including a thermal insulation barrier made up of insulating blocks (1,13) in the form of rectangular parallelepipeds, juxtaposed in parallel rows and each of the primary and secondary elements including a sealing barrier arranged on the thermal insulation barrier, the thermal insulation barrier of the secondary element being secured to the bearing wall (3), the thermal insulation barrier of the primary element being secured by attachment means (8,18) linked to the thermal insulation barrier of the secondary element. Tank according to Claim 2, in which the sealing barrier of the secondary element consists of the metal membrane comprising a plurality of sheets (11) each comprising at least two orthogonal folds (12a, 12b) parallel to the sides of the blocks of thermal insulation (1), and inserted into the interstices (10) provided between the insulation blocks of the secondary element. Tank according to Claim 3, in which the metal membrane plates (11) of the secondary element are made of an alloy of iron with nickel or manganese and having a coefficient of expansion less than or equal to 7.10 ^-6 K ^{- 1} . Tank according to any one of Claims 2 to 4, in which the sealing barrier of the primary element consists of metal sheets (15) welded to each other in a leaktight manner and comprising folds (16a, 16b) directed inside the tank. Tank according to one of Claims 2 to 5, in which an insulation block (1, 13) of the thermal insulation barrier comprises a base plate (2 a , 13 a ) on which is arranged a layer of foam, the bottom plate projecting beyond the foam. Tank according to Claim 6, in which an insulation block (1) of the thermal insulation barrier of the secondary element is held in abutment on the load-bearing wall (3) by means of attachments (9) welded to the wall carrier and cooperating with the projecting areas of the bottom plates (2 a) of the insulation block. Tank according to one of Claims 2 to 7, in which an insulation block (1) of the thermal insulation barrier of the secondary element is held on the load-bearing wall by gluing. Tank according to one of Claims 2 to 8, in which each block of insulation (1) of the thermal insulation barrier of the secondary element carries the said two connecting strips (5,6) which are arranged according to the two axes of symmetry of the rectangle defined by a large face of said insulation block (1). Tank according to Claim 9, in which the means for attaching the thermal insulation barrier of the primary element comprise a continuous metal plate arranged at the intersection of the two connecting strips (5, 6) at the center of the rectangle of each block insulation (1) of the secondary element so as to form a sealed zone (39) on which the corners of four sheets (11) can be welded around said attachment means, and a projecting member (8, 18) crossing the level of the sealing barrier of the secondary element without rising to the level of the sealing barrier of the primary element. Tank according to Claim 10 combined with Claim 6, in which the projecting members are studs (8, 18), the base of which is fixed to the continuous metal plate arranged at the intersection of two connecting strips of the insulation block of the secondary element, an intermediate piece being interposed between, on the one hand, a nut (19,22) cooperating with the thread provided at the free end of the stud and, on the other hand, the overhanging parts of the plates of the insulation blocks of the thermal insulation barrier of the primary element. Tank according to one of Claims 2 to 11, in which each block of insulation (13) of the thermal insulation barrier of the primary element carries two connecting strips (14 a , 14 b ) which are arranged in the vicinity edges of a large face of said insulation block. Tank according to one of claims 1 to 12, in which the connecting strips (5,6,14a,14b) of an insulation block (1,13) are housed in recesses made in the insulation block which carries them so as not to constitute an extra thickness on the corresponding face of the insulation block. Tank according to Claim 13, in which a connecting strip (5,6,14a,14b) of an insulation block is fixed in its recess by screwing, riveting, stapling or gluing. Tank according to one of Claims 1 to 14, in which the adjacent metal sheets (11,15) of the sealing barrier are overlap welded in line with the connecting strips (5,6,14a,14b) carried respectively by the barrier thermal insulation. Tank according to one of Claims 1 to 15, in which the metal sheets (11) which constitute the sealing barrier are rectangular and each comprise two folds arranged along the axes of symmetry of the rectangle formed by the edges of the rectangular sheet. . Tank according to Claim 16, in which the two plies of a sheet (11) of the sealing barrier intersect at the center of the rectangular sheet. Tank according to Claim 16, in which one of the plies of a sheet (11) of the sealing barrier is continuous and the other is interrupted in its central part. Tank according to Claim 18, in which the sealing barrier comprises sheets (31) of a first type which have a continuous fold on their major axis and sheets (32) of a second type have a continuous fold on their minor axis, the sheets of the first and second types (31, 32) being regularly alternated on a vessel wall so that a sheet of one of the types is always surrounded by four sheets of the other type arranged along its four sides. Tank according to one of Claims 1 to 19, in which each insulating block (1) of the thermal insulation barrier comprises two series of orthogonal slots (53a, 53b), each of the said series comprising slots (53a, 53b ) arranged parallel to two opposite sides of the insulation block (1), and in which the sheets (11) of the metal membrane each comprise two series of additional folds (12c, 12d), each of said series of additional folds comprising folds (12c, 12d), orthogonal to the folds (12d, 12c) of the other series, parallel to one of the two folds (12a, 12b) inserted into the interstices (10), and inserted into the slots (53a, 53b) of one of the series of slots (53a, 53b) formed in the insulation block (1). Tank according to one of Claims 1 to 19, in which the metal membrane comprises a second plurality of sheets (11), each of the sheets of the second plurality comprising a single fold (12a) parallel to two opposite sides of the insulation blocks , (1) said ply being inserted into a gap (10) provided between two insulation blocks. Tank according to one of Claims 1 to 19, in which each insulation block (1) of the thermal insulation barrier comprises a slot parallel to two opposite sides of the insulation blocks and in which the metal membrane comprises a second plurality of sheets, each of the sheets of the second plurality comprising a fold (12a) inserted in a slot (53e) provided in a block insulation (1) and a ply (12b) inserted in a gap (10) provided between two insulation blocks. Tank according to one of Claims 1 to 22, in which each of the two connecting strips (5,6) is discontinuous. Tank according to any one of Claims 1 to 22, in which each of the two connecting strips is continuous at the level of the intersection with the other of the two connecting strips (5, 6) and is formed of juxtaposed segments discontinuous in outside the intersection. Vessel (70) for transporting a cold liquid product, the vessel comprising a double hull (72) and a tank (71) according to one of Claims 1 to 24 arranged in the double hull. Use of a ship (70) according to claim 25 for the loading or unloading of a cold liquid product, in which a cold liquid product is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or onshore storage facility (77) to or from the ship's tank (71). Transfer system for a cold liquid product, the system comprising a vessel (70) according to claim 25, insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the vessel to a floating or onshore storage facility (77) and a pump for driving a flow of cold liquid product through the insulated pipes from or to the floating or onshore storage facility to or from the vessel's tank.

Images