FR3090810A1 - Anchoring system for waterproof and thermally insulating tank - Google Patents

Abstract

The invention relates to a sealed and thermally insulating vessel wall for storing a fluid integrated in a support structure, comprising a secondary insulating block and a primary insulating block anchored to the secondary insulating block by a primary anchoring system (97), the primary anchoring system (97) comprising a base (300) fixed to the cover plate, and a movable part (302) retained on the base (300) in the direction of thickness of the wall and movably mounted in the base (300), the moving part (302) comprising a threaded hole (304) opening onto an upper surface of the moving part (302), the upper surface of the moving part (302) flush with an upper surface of the plate cover (7), the movable part being mounted in the base free in translation parallel to the longitudinal direction of a welding wing. Figure to be published: Figure 7

Description

Description

Title of the invention: Anchoring system for waterproof and thermally insulating tank

Technical area

The invention relates to the field of manufacturing sealed and thermally insulated tanks. In particular, the present invention relates to a tank intended to contain cold or hot liquids, and more particularly to tanks for the storage and / or transport of liquefied gas by sea.

Sealed and thermally insulating tanks can be used to store hot or cold products. For example, liquefied natural gas (LNG) is a liquid that can be stored at atmospheric pressure at around -163 ° C in terrestrial storage tanks or in tanks embedded in floating structures.

Technological background

The tanks of ships for the transport of liquefied natural gas generally comprise a double wall successively comprising, from the inside towards the outside of the tank, a primary waterproof membrane, a primary thermally insulating barrier, a secondary waterproof membrane and a secondary thermally insulating barrier.

The patent application FR 2 985 560 describes a sealed and insulating tank in which the primary and secondary thermally insulating barriers are produced in the form of juxtaposed primary and secondary insulating blocks respectively. The secondary insulating block includes a cover plate forming a support surface for the secondary waterproof membrane. The primary insulating block is anchored to the secondary insulating block using an anchoring system. The anchoring system comprises a circular plate surmounted by a circular projection centered on the plate. The circular plate rests on the recess of the cover panel and the projection passes through the cover panel until it is flush with the upper surface of the cover panel. The anchoring system further comprises a cylindrical cavity crossing the thickness of the projection, the inner surface of which is tapped. A cylindrical cage is screwed onto the thread so as to enclose an oblong nut previously placed in the cylindrical cavity. The cage and the projection are flush with the upper surface of the cover panel to carry the secondary waterproof membrane continuously over substantially the entire upper surface of the secondary thermally insulating barrier. The oblong nut and the cage then form a slide. The oblong groove is oriented in a direction parallel to the longitudinal direction of the ship to reduce the stress concentrations in the secondary waterproof membrane during the thermal contraction of the elements of the tank or during the bending of the beam of a ship subjected to the swell.

However, the anchoring system proposed above is not entirely satisfactory. Indeed, the thread of the oblong nut is not flush with the upper surface of the cover panel. This results in a certain difficulty when mounting a flanged stud which must be inserted, through a hole in the waterproof membrane, into the threads of the oblong nut. In addition, the cage is fixed by screwing, which generates some inaccuracies in the direction of the degree of freedom. This can have the effect of creating stress concentrations on the secondary waterproof membrane.

Patent application ER 2 887 010 also describes a sealed and insulating tank in which the primary and secondary thermally insulating barriers are produced in the form of respectively primary and secondary insulating blocks juxtaposed. Each secondary insulating block comprises a cover plate forming a support surface for the secondary waterproof membrane. An anchoring device makes it possible to anchor a primary insulating block to four adjacent secondary insulating blocks. The anchoring device consists of a square plate with bevelled corners. The cover panels have a housing, thus the plate is housed in the four housings of the four adjacent secondary insulating blocks and retained in the housings. The cover panels include counterbores located at the periphery of the housings and in which the stop plates are located, so as to touch with the upper surface of the cover panels. The stop plates include bores for fixing the stop plates to the cover panels with fixing screws. In addition, the plate includes a central boss which is flush with the stop plates and the upper surface of the cover panels. Thus the secondary waterproof membrane rests on a flat surface. The plate also includes a cylindrical socket projecting from the face opposite the boss and pierced with a threaded bore. The secondary waterproof membrane is pierced to allow the passage of a stud, which anchors a primary insulating block. The stud has a threaded lower part which is screwed into the threaded bore.

The anchoring system proposed above is not entirely satisfactory. Indeed, the fixing means of the plate authorizes the latter to have two degrees of freedom in translation and thus risks imposing a concentration of tension on the secondary waterproof membrane. In addition, the multiplicity of parts for fixing the plate to the cover panel are all risks of creating roughness on the surface on which the secondary waterproof membrane must rest. These roughness can cause undesirable wear of the waterproof membrane.

summary

An idea underlying the invention is to provide a wall of a sealed and thermally insulating tank which does not have these drawbacks. Thus the object of the invention is to better control the flatness of the surface of the thermally insulating barrier and the movements of the primary insulating blocks relative to the waterproof membrane.

To this end, the present invention relates to a wall of a sealed and thermally insulating tank for storing a fluid integrated in a support structure, the tank wall comprising successively, in a thickness direction of the wall, a secondary insulating barrier retained at the supporting structure, a secondary waterproof membrane resting against the secondary insulating barrier, a primary insulating barrier resting against the secondary impermeable membrane and a primary waterproof membrane resting against the primary insulating barrier and in which the insulating barrier secondary comprises a secondary insulating block comprising a cover plate forming a support surface for the secondary waterproof membrane, in which said secondary waterproof membrane comprises a plurality of metal strakes with edges raised towards the inside of the tank, said strakes being welded two two, by their raised edges, on two sides of a weld wing re held mechanically on the secondary insulating block, said welding wing being partially engaged in a groove made in the cover plate and extending in a longitudinal direction, in which the primary insulating barrier comprises a primary insulating block anchored to the secondary insulating block by a primary anchoring system, the primary anchoring system comprising a base fixed to the cover plate, and a movable part retained on the base in the thickness direction of the wall and movably mounted in the base, the movable part comprising a tapped hole opening onto an upper surface of the movable part, the upper surface of the movable part flush with an upper surface of the cover plate, the movable part being mounted in the free base in translation at least parallel to the longitudinal direction of the welding wing.

In a preferred mode, the movable part is mounted in the free base in translation parallel to the longitudinal direction of the welding wing and more particularly can be guided in translation parallel to said longitudinal direction.

The tapped hole opens onto the upper surface of the moving part which is flush with the upper surface of the cover plate. This makes it easier to screw a part into the tapped hole in the future.

The base is arranged so that the movable part can have a translational movement at least parallel to the longitudinal direction of the welding wing. This makes it possible to reduce the mechanical stresses on the waterproof membrane, for example during the cooling of the tank which causes the retraction of the thermally insulating barrier.

The moving part is flush with the surface of the secondary insulating block and limits the abrasion of the secondary waterproof membrane.

According to one embodiment, the base has a bottom wall arranged under the moving part and a recess to receive a lower part of the moving part, the recess being delimited by side walls so as to guide the part movable parallel to the longitudinal direction.

According to one embodiment, the primary anchoring system further comprises a ring configured to sandwich the lower part of the moving part using the base.

According to one embodiment, the ring has an oblong recess so that the moving part is guided in the longitudinal direction parallel to the longitudinal direction of the strake.

According to one embodiment, the ring is fixed to the base by welding.

According to one embodiment, the upper part of the ring is flush with the upper surface of the cover plate.

According to one embodiment, the lower part of the movable part comprises a projection extending radially all along the lower part.

According to one embodiment, the movable part is arranged on an upper surface of the base and has oblong passages oriented parallel to the longitudinal direction, and the base carries retaining screws engaged in the oblong passages and retaining the moving part slidingly on said base.

According to one embodiment, a stud has a threaded lower part configured to be screwed into the tapped hole.

According to one embodiment, the stud has a collar extending over the moving part.

According to one embodiment, the flange is arranged to bring the sealed secondary membrane into contact with the moving part.

According to one embodiment, the flange is welded at the periphery to the secondary waterproof membrane in a leaktight manner

According to one embodiment, the bottom wall is fixed to the lower part of the moving part by welding or by screwing and then welding

According to one embodiment, the base has a shoulder at the level of the recess arranged so that the bottom wall can be in contact against the shoulder.

According to one embodiment, the primary anchoring system further comprises at least one washer and at least one nut cooperating with threaded upper parts of said stud to retain said washer resting on a bottom plate of the primary insulating block .

According to one embodiment, the cover plate comprises a recess in which the base is housed.

According to one embodiment, the primary anchoring system comprises a foam arranged so as to absorb the movements of the moving part in the anchoring system.

According to one embodiment, the primary anchoring system comprises a washer arranged between the ring and the moving part.

According to one embodiment, the washer comprises polytetrafluoroethylene (PTFE).

Such a tank can be part of a terrestrial storage installation, for example to store LNG or be installed in a floating structure, coastal or deep water, in particular an LNG tanker, a floating storage and regasification unit ( FSRU), a floating production and remote storage unit (FPSO) and others. Such a tank can also serve as a fuel tank in any type of ship.

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

According to one embodiment, the invention also provides a method of loading or unloading of such a vessel, in which a cold liquid product is conveyed through isolated pipes from or to a floating or land storage installation towards or from the vessel.

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

Brief description of the figures

. The invention will be better understood, and other objects, 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 illustration and without limitation. , with reference to the accompanying drawings.

[Fig-1] Figure 1 is a cutaway perspective view of a tank wall.

[Fig.2] Figure 2 is an enlarged view of area 1 of Figure 1, showing a secondary insulating panel which can be used in the tank wall and further showing a primary anchoring system according to one mode of achievement

[Fig.3] Figure 3 a perspective view of a primary insulating panel which can be used in the tank wall.

[Fig-4] Figure 4 is a schematic perspective view of an anchoring system according to a first embodiment.

[Fig.5] Figure 5 is a schematic cutaway perspective view of the anchoring system according to the first embodiment.

[Fig.6] Figure 6 is a schematic cutaway perspective view of an anchoring system according to a second embodiment.

[Fig.7] Figure 7 is a schematic perspective view of an anchoring system according to a third embodiment.

[Fig.8] Figure 8 is a schematic perspective view of the anchoring system according to the third embodiment.

[Fig.9] Figure 9 is a schematic cutaway perspective view of an anchoring system according to a fourth embodiment.

[Fig. 10] Figure 10 is a schematic cutaway perspective view of an anchoring system according to a fifth embodiment.

[Fig.l 1] Figure 11 is a schematic view of the stud cooperating with an anchoring system according to a sixth embodiment.

[Fig. 12] Figure 12 is a schematic view of a stud for an anchoring system.

[Fig. 13] Figure 13 is a diagram of the anchoring system mounted in a secondary insulating block.

[Fig. 14] Figure 14 is a cutaway schematic representation of an LNG tank and a loading / unloading terminal for this tank. Description of the embodiments

In Figure 1, there is shown the multilayer structure of a sealed and thermally insulating tank 1 for the storage of a liquefied fluid, such as liquefied natural gas (LNG). The tank 1 has a generally polyhedral shape and comprises several walls. The wall of the tank 1 successively comprises, in the thickness direction, from the outside towards the inside of the tank 1, a secondary thermally insulating barrier 2 retained at a support structure 3, a secondary waterproof membrane 4 resting against the secondary thermally insulating barrier 2, a primary thermally insulating barrier 5 resting against the secondary waterproof membrane 4 and a primary waterproof membrane 6 intended to be in contact with the liquefied natural gas contained in the tank 1.

The supporting structure 3 of the tank 1 can in particular be formed by the hull or the double hull of a ship. The support structure comprises a plurality of support walls 3 defining the general shape of the view, usually a polyhedral shape.

The secondary thermally insulating barrier 2 comprises a plurality of secondary insulating blocks 7 which are anchored to the carrier wall 3 by means of secondary anchoring systems 98. The secondary insulating blocks 7 have a generally parallelepiped shape and are arranged in parallel rows. Three rows are indicated by the letters A, B and C. Socks of mastic (not shown) are interposed between the secondary insulating blocks 7 and the support wall 3 to make up for the deviations of the support wall 3 with respect to a flat surface of reference. Kraft paper can be inserted between the mastic strands and the supporting wall 3 if it is desired to prevent adhesion of the mastic strands on the supporting wall 3.

The secondary anchoring systems 98 may be in various numbers ranging for example from 2 to 6 per secondary insulating block 7 and placed for example at the corners of 4 secondary insulating blocks and / or in the gap between two secondary insulating blocks either in the first direction or in the second direction.

Figure 2 shows the structure of a secondary insulating block 7 according to one embodiment. The secondary insulating block 7 here comprises two plates, namely a bottom plate 8 and a cover plate 10. The secondary insulating block 7 also comprises a block of insulating polymer foam 11 sandwiched between the bottom plate 8 and the plate of cover 10. The block of insulating polymer foam 11 is bonded to the bottom plate 8 and the cover plate 10. The insulating polymer foam can in particular be a polyurethane-based foam, optionally reinforced with fibers. The bottom 8 and cover 10 plates are for example made of plywood.

According to an embodiment not shown, the secondary insulating block comprises a bottom plate, a cover plate and side plates. The side plates connect the cover plate to the bottom plate and keep them at a distance from each other to define an interior space of the secondary insulating block capable of receiving one or more insulating materials. The bottom, cover and side plates are for example made of plywood. The interior space of the secondary insulating block can then be filled with a thermal insulation lining, for example perlite or polyurethane foam optionally reinforced with fiberglass fabrics or glass wool.

According to an embodiment not shown, the secondary insulating block comprises a first block of high density polymer foam, a bottom plate bonded under the first block of high density polymer foam, an intermediate plate bonded to the first block of polymer foam, a second block of polymer foam bonded to the intermediate plate and a cover plate bonded to the second block of polymer foam as for example described in the document LR3000042 A1. According to an alternative embodiment, each primary insulating block is straddles four secondary insulating blocks and is thus staggered with respect to said four secondary insulating blocks. According to other variants, each primary insulating block straddles two or six secondary insulating blocks.

According to other embodiments, the primary and secondary insulating blocks have a different structure.

Returning to FIG. 1, it can be seen that the secondary waterproof membrane 4 comprises a continuous ply of strakes 21, metallic, with raised edges 32 towards the inside of the tank. The strakes 21 are welded in pairs, by their raised edges 32, on the two faces of a welding wing. The welding wings have a square section. The raised edges 32 of the strakes 21 are welded to an arm of the bracket, while the other arm is engaged in a groove 20 formed on the cover plates 10 of the secondary insulating blocks 7. The cover plates 10 comprise a plurality of parallel grooves 20, the distance between two grooves 20 corresponding to the width of a strake 21, while the distance between a free edge of a block and an adjacent groove 20 corresponds to the width of a strake 21, so that a strake makes the junction between two adjacent insulating blocks 7. Thus, the secondary waterproof membrane 4 is retained on the secondary thermally insulating barrier 2. The weld wings and the grooves 20 form sliding joints allowing the strakes 21 to contract and deform relative to the secondary insulating blocks 7.

The strakes 21 are, for example, made of Invar®: that is to say an alloy of iron and nickel, the coefficient of expansion of which is typically between 1.2 × 10 ⁶ and 2.10 ⁶ K ¹ . It is also possible to use alloys of iron and manganese whose coefficient of expansion is typically of the order of 7 to 9 10 ⁶ K *.

Referring to Figure 1, the primary thermally insulating barrier 5 comprises a plurality of primary insulating blocks 22 superimposed astride two rows of secondary insulating blocks 7. The primary insulating blocks 22 are anchored on the secondary insulating blocks 7 thanks to primary anchoring systems 97. The primary anchoring systems 97 are separated and offset from the secondary anchoring systems 98. The primary insulating blocks 22 have a generally parallelepiped shape and are arranged in parallel rows. In addition, they have dimensions identical to those of the primary insulating blocks 22 with the exception of their thickness in the thickness direction of the wall 1 of the tank which is likely to be different, and in particular smaller.

Figure 3 shows the structure of a primary insulating block 22 according to one embodiment. The primary insulating block 22 has a structure similar to that of the secondary insulating block 7 of FIG. 2. Also, the primary insulating block 22 comprises a bottom plate 23 and a cover plate 27. The primary insulating block 22 also comprises a block of insulating polymer foam 25 sandwiched between the bottom plate 23 and the cover plate 27. The block of insulating polymer foam is bonded to the bottom plate 23 and the cover plate 27. The insulating polymer foam can in particular be a polyurethane foam, optionally reinforced with fibers. The bottom plates 23 and cover 27 are for example made of plywood.

According to an embodiment not shown, the primary insulating block comprises a bottom plate, a cover plate and side plates. The side plates connect the cover plate to the bottom plate and keep them at a distance from each other to define an interior space of the primary insulating block capable of receiving one or more insulating materials. The bottom, cover and side plates are for example made of plywood. The interior space of the primary insulating block can then be filled with a thermal insulation lining, for example perlite or polyurethane foam optionally reinforced with fiberglass or glass wool fabrics.

The primary insulating block 22 has recesses 28 at its corner areas so that the bottom plate 23 projects beyond the insulating polymer foam block 25 and the cover plate 27. Thus, the bottom plate 23 forms at the corner areas of the primary insulating block 22 a support area 29 intended to cooperate with the primary anchoring system 97. Not shown, a shim can be added to the bottom plate 23 , said shim having a shape analogous to that of the support zone 29 and being intended to cooperate with the primary anchoring system 97.

The bottom plate 23 has grooves 31 intended to receive the raised edges 32 of the strakes 21 of the secondary waterproof membrane 4. The cover plate 27 may also include anchoring means, not shown in FIGS. 1 and 3, to anchor the primary waterproof membrane 6.

The structure of the primary insulating block 22 is described above by way of example. Also, in another embodiment, the primary insulating blocks 22 are likely to have another general structure.

In another embodiment, the primary thermally insulating barrier 5 comprises primary insulating blocks 22 having at least two different types of structure, for example the two aforementioned structures, depending on their location in the tank.

Figure 1 also shows that the primary waterproof membrane 6 comprises a continuous sheet of rectangular sheets 33 which have two series of mutually perpendicular undulations. The first series of undulations 55 extends perpendicular to the rows of insulating blocks A, B, C and therefore perpendicular to the raised edges 32 of the strakes 21 and has regular spacing 57. The second series of undulations 56 extends parallel to the rows of insulating blocks A, B, C and therefore parallel to the raised edges 32 of the strakes 21 and has regular spacing 58. Preferably, the first series of corrugations 55 is higher than the second series of corrugations 56.

According to other embodiments, the primary waterproof membrane has a structure similar to that of the secondary waterproofing membrane, that is to say that it consists of an assembly of strakes with raised edges. .

Figures 4 to 9 show the different embodiments of the primary anchoring system.

Referring to Figures 4 and 5, the primary anchoring system 97, according to a first embodiment, comprises a base 100 intended to be fixed to the cover plate 10 of the secondary insulating block 7 and a movable part 102 The base 100 is a cylinder of revolution whose height is smaller than the radius. In its center, the base 100 has a recess 108 to accommodate a lower part 110 of the moving part 102. The recess 108 is delimited by side walls 112 to limit the movement of the lower part 110 of the moving part 102 in the recess 108. The base 100 further comprises a bottom wall 106 arranged under the movable part 102. The bottom wall 106 and the base 100 are made in one piece. The movable part 102 and the bottom wall 106 are preferably made of metal such as invar® as described above or of stainless steel type 304L. Thus the friction between the moving part 102 and the bottom wall 106 is minimized in the event of contact.

The moving part 102 comprises an upper part 114, a lower part 110 and a hole 104 opening onto the upper surface of the upper part 114. The hole 104 is intended to cooperate with a stud to fix a primary insulating block 22 to a secondary block 7. It can be tapped so that the stud is screwed to the moving part 102. The lower part 110 has a circular shape. The side walls 112 can define an oblong shape or a circular shape whose dimensions are greater than the dimensions of the lower part 110.

The upper part 114 extends above the base 100 and has four oblong passages 118. The oblong passages 118 extend in a longitudinal direction. This longitudinal direction is parallel to the direction in which the weld wing extends. The base 100 carries retaining screws engaged in the oblong passages 118 and retaining the movable part 100 in a sliding manner on said base in the longitudinal direction. The upper part 114 thus rests on the base 100 which provides it with a sliding support.

When the moving part 102 and the base 100 are assembled and the assembly is mounted on the cover plate 10, the upper surface of the upper part 114 is then flush with an upper surface of the cover plate 10. The cover plate 10 then covers the rest of the anchoring system 97.

Referring to FIG. 6, the primary anchoring system 97, according to a second embodiment, comprises a base 200 intended to be fixed to the cover plate 10 of the secondary insulating block 7 and a moving part 202. The base 200 is a cylinder of revolution whose height is smaller than the radius. In its center, the base 200 has a through recess 208 to receive a lower part 210 of the moving part 202. The recess 208 is delimited by side walls 212 to limit the displacement of the lower part 210 of the moving part 202 in recess 208.

The moving part 202 comprises an upper part 214, a lower part 210 and a hole 204 opening onto the upper surface of the upper part 214. The upper part 214 extends above the base 200 and rests on the latter, the base 200 thus provides a sliding support for the moving part 202.

The hole 204 is intended to cooperate with a stud to fix a primary insulating block 22 to a secondary block 7. It can be tapped so that the stud is screwed to the moving part 202. The lower part 210 has a circular shape . The side walls 212 may define an oblong shape or a circular shape whose dimensions are greater than the dimensions of the lower part 210.

The bottom wall 206 is fixed to the lower part 210 of the movable part 202. It can be fixed by welding or by screwing and then welding. The base 200 has a shoulder 230 at the level of the recess 208 arranged so that the bottom wall 206 can be in contact against the shoulder 230. Preferably, the contact is without pressure in order to allow sliding.

The moving part can be guided in the longitudinal direction in which the welding wing extends if the recess 208 is oblong and the bottom wall 206 and / or the lower part 210 are circular. Alternatively, the guide may also be along a plane defined by the longitudinal direction in which the welding wing extends and a direction orthogonal to the longitudinal direction provided that the bottom wall 206, the recess 208 and the lower part 210 have a complementary circular shape, each of different size.

When the moving part 202 and the base 200 are assembled and the assembly is mounted on the cover plate 10, the upper surface of the upper part 214 is then flush with an upper surface of the cover plate 10. The cover plate 10 then covers the rest of the anchoring system 97.

Referring to Figures 7 and 8, the primary anchoring system 97, according to a third embodiment, comprises a base 300 intended to be fixed to the cover plate 10 of the secondary insulating block 7 and a movable part 302 The base 300 is a cylinder of revolution whose height is smaller than the radius. In its center, the base 300 has a recess 308 to receive a lower part 310 of the moving part 302. The recess 308 is delimited by side walls 312 to limit the displacement of the lower part 310 of the moving part 302 in the recess 308.

The moving part 302 comprises an upper part 314, a lower part 310 and a hole 304 opening onto the upper surface of the upper part 314. The lower part comprises a projection 330. Preferably the projection 330 extends radially all along the lower part 310 The anchoring system 97 further comprises a ring 316 configured to sandwich the lower part 310, that is to say the projection 330, of the moving part 302 using the base 300. The ring 316 has an oblong recess so that the moving part 302 is guided in a longitudinal direction parallel to the longitudinal direction in which the welding wing extends.

Alternatively, the recess 308 may have an oblong shape and the lower part 310 a circular shape so as to guide the moving part 302 in a longitudinal direction

The hole 304 is intended to cooperate with a stud to fix a primary insulating block 22 to a secondary block 7. It can be tapped so that the stud is screwed to the moving part 302. The lower part 310 has a circular shape . The side walls 312 can define an oblong shape or a circular shape whose dimensions are greater than the dimensions of the lower part 310.

The base 300 further comprises a bottom wall 306 arranged under the moving part 302. The bottom wall 306 and the base 300 have come in one piece. The moving part 302 and the bottom wall 306 are preferably made of metal such as invar® as described above. Thus the friction between the moving part 302 and the bottom wall 306 is minimized in the event of contact.

The ring 316 has four circular passages 318. The base 300 carries screws engaged in the circular passages and retaining the ring 316 on the base. Part of the ring 316 rests and is fixed to the base 300 and another part keeps the moving part 302 in a sliding position in the recess 308.

When the moving part 302 and the base 300 are assembled and the assembly is mounted on the cover plate 10, the upper surface of the upper part 314 is then flush with an upper surface of the cover plate 10. The cover plate 10 then covers the rest of the anchoring system 97.

Referring to Figure 9, the primary anchoring system 97, according to a fourth embodiment, is similar to the third embodiment. However, it differs in that the recess of the ring is circular and the recess 308 is also circular. Thus the moving part can move in a plane defined by the longitudinal direction in which the welding aid extends and a direction orthogonal to the longitudinal direction.

Referring to Figure 10, the primary anchoring system 97, according to a fifth embodiment, is similar to the fourth embodiment. It differs only in that the ring 316 is welded on its periphery external to the base 300 instead of being screwed.

Referring to Figure 11, the primary anchoring system 97, according to a sixth embodiment, comprises a base 400 intended to be fixed to the cover plate 10 of the secondary insulating block 7 and a movable part 402. The base 400 is a cylinder of revolution whose height is smaller than the radius, the moving part 402 coming to bear on the base 400.

The moving part 402 comprises an upper part 414, a lower part 410 and a hole 404 opening onto the upper surface of the upper part 414. The lower part comprises a projection 430. Preferably the projection 430 extends radially all along the lower part 410. The anchoring system 97 further comprises a ring 416 configured to sandwich the lower part 410, that is to say the projection 430, of the moving part 402 using of the base 400. The ring 416 can have an oblong recess so that the movable part 402 is guided in a longitudinal direction parallel to the longitudinal direction in which the welding wing extends.

The hole 404 is intended to cooperate with a stud 35 to fix a primary insulating block 22 to a secondary block 7. It can be tapped so that the stud is screwed to the moving part 402. The lower part 410 has a shape circular. The side walls 412 can delimit an oblong shape or a circular shape whose dimensions are greater than the dimensions of the lower part 410. The space 408 thus created can then be filled by putting a foam 600. This foam 600 will serve as a device for centering and shock absorber.

The ring 416 has four circular passages, not shown. The base 400 carries screws engaged in the circular passages and retaining the ring 316 on the base. Alternatively, the ring 416 can be welded to the base 400.

Part of the ring 416 rests and is fixed on the base 400 and another part keeps the moving part 402 in the sliding position at its center. In this embodiment, the ring 416 guides the sliding part 402. Between the part of the ring 416 resting on the moving part 402, and the moving part 402, a washer 500 can be incorporated. Preferably, the washer 500 is made of polytetrafluoroethylene (PTFE).

When the moving part 402 and the base 400 are assembled and the assembly is mounted on the cover plate 10, the upper surface of the upper part 414 is then flush with an upper surface of the cover plate 10. The cover plate 10 then covers the rest of the anchoring system 97.

The use of the washer 500 and the foam can be extended to the other embodiments and is therefore not limited to this embodiment.

At the threaded hole 104, 204, 304, 404, of the moving part 102, 202, 302, 402, the secondary waterproof membrane 7 is drilled to allow the passage of a stud 35. The stud 35 will allow following the fixing of the primary insulating block 7 to the secondary insulating block 22 as will be described.

Referring to Figure 12, the stud 35 includes a flange 34 and a threaded lower part 90 located under the flange 34. The threaded lower part is intended to be screwed into the hole 104, 204, 304, 404 threaded the moving part 102, 202, 302, 402.

. Above the collar 34 and below the threaded upper part 91, the stud 35 has, from bottom to top, a section 91 of diameter greater than that of the part 51, a section 92 of diameter equal to or slightly less than that of the section 91, and having and at least one flat 94 making it possible to offer a grip with a wrench or another tool for screwing the stud 35 into the hole 104, 204, 304, 404 tapped, and a non-threaded section 93 of diameter substantially equal to that of the threaded upper part 51.

The stud 35 retains fixing means (not shown), comprising a flat washer, one or more Belleville washers and a nut coming into contact on the bearing zones 29 in order to maintain the primary insulating blocks 9. The washers are located at the section 93 and the nut is screwed onto the threaded upper part 51.

If the length and / or the width of the primary blocks 8 is large, one or more primary anchoring systems can be provided, arranged along said length and / or width, these possible primary anchoring systems having a structure similar to that of the primary anchoring systems described above.

The stud 35 has a flange 34 intended to be welded on its periphery to the secondary waterproof membrane 4, around the hole made to reveal the hole 104, 204, 304, 404. Thus the continuity of the sealing of the secondary waterproof membrane 4 is ensured. The secondary waterproof membrane is therefore sandwiched between the collar 34 of the stud 35 and the upper surface the upper part 114, 214, 314, 414 of the moving part 102, 202, 302, 402.

Referring to Figure 13, a recess 12 is formed in the cover plate 10 of a secondary insulating block 7 so that the free ends of the base 100, 200, 300, 400, come in pressing against the cover plate 10 on the side facing the block of insulating polymer foam 11. The recess 12 is located in the center of the cover plate 10. The cover plate 10 is thick enough for the base 100, 200 , 300, 400, once mounted in the recess 12, does not exceed the lower surface of the cover plate 10. The recess reveals only the upper surface of the upper part 114, 214, 314, 414, of the movable part 102, 202, 302, 402 so that the upper surface of the upper part 114, 214, 314, 414 is flush with the upper surface of the secondary insulating block 7.

Then, the primary anchoring system 97 is fixed to the cover plate 10 by screwing or any other suitable means. Then the cover plate 10 is glued to the block of insulating polymer foam 11 in order to obtain the secondary insulating block 7. Next, the secondary insulating block 7 is anchored to the load-bearing wall 3 by means of a secondary anchoring system 98. A Once all the secondary insulating blocks 7 have been anchored, the secondary waterproof membrane 4 is mounted and drilling is carried out at each hole 104, 204, 304, 404, in order to allow the studs to be screwed thereafter.

The stud 35 is then screwed into the hole 104, 204, 304, 404, of the movable part 102, 202, 302, 402 and is welded by means of its collar to the secondary waterproof membrane 4, around the drilling. Thus, the continuity of the sealing of the secondary waterproof membrane 4 is ensured. Four primary insulating blocks 22 are then placed around the free end of the stud 35 and rest on the secondary waterproof membrane 4. One or more Belleville washers are threaded on the stud 35 to be at the section 93. The washers are then in contact with the bearing zones 29 of the primary insulating blocks 22. Finally, a nut is screwed onto the threaded upper part 51 to hold the primary insulating blocks 22 to the secondary insulating blocks 7 by tightening.

Referring to Figure 14, 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 tank 71 comprises a primary waterproof barrier intended to be in contact with the LNG contained in the tank, a secondary waterproof barrier arranged between the primary waterproof barrier and the double hull 72 of the ship, and two insulating barriers arranged respectively between the primary waterproof barrier and the secondary waterproof barrier and between the secondary waterproof barrier and the double-shell 72.

In a manner known per se, loading / unloading lines 73 arranged on the upper deck of the ship can be connected, by means of appropriate connectors, to a maritime or port terminal for transferring a cargo of LNG from or to the tank. 71.

FIG. 14 represents an example of a maritime terminal comprising a loading and unloading station 75, an underwater pipe 76 and an onshore installation 77. The loading and unloading station 75 is a fixed offshore installation comprising a movable arm 74 and a tower 78 which supports the movable arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading / unloading lines 73. The movable arm 74 can be adjusted to suit all sizes 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 ship 70 from or to the shore installation 77. This comprises liquefied gas storage tanks 80 and connection pipes 81 connected by the submarine pipe 76 to the loading and unloading station 75. The submarine pipe 76 allows the transfer of liquefied gas between the loading and unloading station 75 and the shore installation 77 over a long distance, for example 5 km, which makes it possible to keep the ship 70 at a great distance from the coast during the loading and unloading operations.

To generate the pressure necessary for the transfer of the liquefied gas, on-board pumps are implemented in the ship 70 and / or pumps equipping the shore installation 105 and / or pumps equipping the loading and unloading station 75.

Although the invention has been described in conjunction 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 are within the scope of the invention.

The use of the verb "behave", "understand" or "include" and its conjugate forms does not exclude the presence of other elements or steps than those set out in a claim.

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

Claims (1)

Wall of a sealed and thermally insulating tank (1) for storing a fluid integrated in a support structure (3), the tank wall (1) successively comprising, in a thickness direction of the wall, an insulating barrier secondary (2) retained at the supporting structure (3), a secondary waterproof membrane (4) resting against the secondary insulating barrier (2), a primary insulating barrier (5) resting against the secondary waterproof membrane (4) and a waterproof membrane primary (6) resting against the primary insulating barrier (5) and in which the secondary insulating barrier (2) comprises a secondary insulating block (7) comprising a cover plate (10) forming a support surface for the secondary waterproof membrane ( 4), wherein said secondary waterproof membrane (4) comprises a plurality of metal strakes (21) with raised edges (32) towards the interior of the tank, said strakes (21) being welded in pairs, by their raised edges (32), on two sides es of a weld wing mechanically retained on the secondary block (7), said weld wing being partially engaged in a groove (20) formed in the cover plate (7) and extending in a longitudinal direction, in which the primary insulating barrier (5) comprises a primary insulating block (22) anchored to the secondary insulating block (7) by a primary anchoring system (97), the primary anchoring system (97) comprising a base (100, 200 , 300, 400) fixed to the cover plate (7), and a moving part (102, 202, 302, 402) retained on the base (100, 200, 300) in the thickness direction of the wall and movable mounted in the base (100, 200, 300, 400), the movable part (102, 202, 302, 402) comprising a tapped hole (104, 204, 304) opening onto an upper surface of the movable part (102 , 202, 302, 402), the upper surface of the moving part (102, 202, 302, 402) flush with an upper surface of the cover plate (7), the moving part (102, 202, 302, 402) being mounted in the free base in translation at least parallel to the longitudinal direction of the welding wing. Tank wall (1) according to claim 1, wherein the base (100, 200, 300) has a bottom wall (106, 206, 306) arranged under the moving part and a recess (108, 208, 308) to receive a lower part (110, 210, 310) of the movable part (102, 202, 302), the recess (108, 208, 308) being delimited by side walls (112, 212, 312) so as to guide the moving part parallel to the longitudinal direction. [Claim 3] Tank wall (1) according to one of the preceding claims, in which the primary anchoring system (97) further comprises a ring (316) configured to sandwich the lower part (310) of the moving part (302 ) using the base (300). [Claim 4] Tank wall (1) according to the preceding claim, wherein the ring (316) has an oblong recess so that the movable part is guided in the longitudinal direction parallel to the longitudinal direction of the strake (21). [Claim 5] Tank wall (1) according to one of claims 3 and 4, wherein the upper part of the ring (316) is flush with the upper surface of the cover plate (7). [Claim 6] Tank wall (1) according to one of claims 1 and 2, in which the moving part (102) is arranged on an upper surface of the base and has oblong passages (118) oriented parallel to the longitudinal direction, and the base (100) carries retaining screws engaged in the oblong passages (118) and retaining the movable part (102) in a sliding manner on said base (100). [Claim 7] Tank wall (1) according to one of the preceding claims, in which a stud (35) having a threaded lower part (90) configured to be screwed into the tapped hole (104, 204, 304). [Claim 8] Tank wall (1) according to claim 7, wherein the stud (35) has a flange (34) extending over the movable part (102, 202, 302). [Claim 9] Tank wall (1) according to claim 8, wherein the flange (34) is arranged to bring the secondary waterproof membrane (4) into contact with the moving part (102, 202, 302). [Claim 10] Tank wall (1) according to one of claims 8 or 9, in which the flange (34) is welded on the periphery to the secondary waterproof membrane (4) in a leaktight manner. [Claim 11] Tank walls (1) according to the preceding claim, wherein the primary anchoring system (97) further comprises at least one washer and at least one nut cooperating with threaded upper parts of said stud (35) to retain said washer in support on a bottom plate (23) of the primary insulating block (22). [Claim 12] Ship for the transport of a cold liquid product, the ship comprising a double hull and a tank placed in the double hull, the tank being a tank comprising walls according to one of claims 1 to 11. [Claim 13] Transfer system for a cold liquid product, the system comprising a ship according to claim 12, insulated pipes arranged so as to connect the tank installed in the hull of the ship to a floating or land storage installation and a pump to drive a flow of cold liquid product through the insulated pipes from or to the floating or ground storage facility to or from the vessel of the ship. [Claim 14] A method of loading or unloading a ship according to claim 12, wherein a cold liquid product is conveyed through insulated pipes from or to a floating or land storage facility to or from the vessel of the ship.