FR3110950A1 - ANCHORING DEVICE INTENDED TO RETAIN INSULATING BLOCKS - Google Patents

Abstract

An anchoring device intended to retain insulating blocks against a load-bearing wall comprises a clamping assembly (30) comprising a lower plate (31), an upper plate (32) parallel to the lower plate, and an abutment piece (33 ) rigid defining a minimum spacing between the lower plate and the upper plate. The spacing member further comprises an elastically compressible member (39) tending to maintain the lower plate and the upper plate (32) in a separated position, the connecting member defining a maximum spacing between the lower plate and the upper in the spaced apart position, said maximum spacing being greater than said minimum spacing, the elastically compressible member (39) being configured to be elastically compressed up to said abutment position of the lower and upper plates (31, 32) against the part of stop (33) in response to a force tending to bring the upper plate closer to the lower plate. Fig. 3

Description

ANCHORAGE DEVICE INTENDED TO RETAIN INSULATING BLOCKS

The invention relates to the field of sealed and thermally insulating tanks integrated into a supporting structure to contain a cold fluid, in particular to membrane tanks to contain liquefied gases, and in particular to mechanical anchoring devices that can be used in such a tank.

Sealed and thermally insulating tanks can be used in different industries to store cold products. For example, in the field of energy, liquefied natural gas (LNG) is a liquid with a high methane content that can be stored at atmospheric pressure at approximately -163°C in onshore storage tanks or in onboard tanks. in floating structures. Liquefied Petroleum Gas (LPG) can be stored at a temperature between -50°C and 0°C.

In the case of a floating structure, the tank may be intended for the transport of liquefied gas or to receive liquefied gas used as fuel for the propulsion of the floating structure.

We know, for example from documents WO-A-2014096600 and WO-A-2019110894, a sealed and thermally insulating tank for storing liquefied natural gas arranged in a supporting structure and whose walls have a multilayer structure, namely 'exterior to the interior of the tank, a secondary thermally insulating barrier anchored against the load-bearing structure, a secondary sealing membrane which is supported by the secondary thermally insulating barrier, a primary thermally insulating barrier which is supported by the secondary sealing and a primary sealing membrane which is supported by the primary thermally insulating barrier and which is intended to be in contact with the liquefied natural gas stored in the tank.

Each thermal insulation barrier, primary and secondary, comprises a set of modular insulating blocks, respectively primary and secondary, of generally parallelepiped shape which are juxtaposed and which thus form a support surface for a respective sealing membrane. The insulating blocks are anchored to the supporting structure by means of anchoring devices which are fixed to the supporting structure and which are positioned at the corners of the primary and secondary insulating blocks. Each anchoring device thus cooperates with the corners of four adjacent secondary insulating blocks and with the corners of four adjacent primary insulating blocks in order to retain them against the load-bearing structure.

Certain aspects of the invention start from the observation that the walls of the tank can undergo significant and localized compressive stresses due to the phenomena of sloshing of the liquids contained in the tanks. However, the anchoring devices are made with components that are generally stiffer than the insulating blocks in order to be able to reliably anchor the thermally insulating barriers while having a limited footprint. These differences in stiffness lead to a risk of creating defects in the flatness of a thermally insulating barrier in response to compressive stresses, in particular when the thermally insulating barrier is essentially made of polymer foam. These flatness defects can cause stress concentrations at the anchoring devices which would be detrimental to the integrity of the waterproof membrane supported by the thermally insulating barrier.

An idea at the base of the invention consists in introducing a flexibility of the anchoring devices in the direction of a compressive force coming from the interior of the tank, with a view to homogenizing the response of a thermally insulating barrier. to compressive stresses. Another idea underlying the invention consists in allowing the upper surface of an anchoring device to approximately follow the movements of the upper surface of the insulating blocks during the operation of a sealed and thermally insulating tank. membrane.

For this, the invention proposes an anchoring device intended to retain insulating blocks against a load-bearing wall, comprising:
a clamping assembly comprising a lower plate, an upper plate parallel to the lower plate, a connecting member linking the lower plate to the upper plate and a spacing member arranged between the lower plate and the upper plate, the connecting member spacing comprising a rigid abutment part defining a minimum spacing between the lower plate and the upper plate in a position of abutment of the lower and upper plates against the abutment part, and
an anchor rod projecting from the clamping assembly perpendicular to the lower plate, the anchor rod having a lower end intended to be attached to a load-bearing wall and an upper end opposite the lower end and coupled to the lower plate to be able to exert traction on the lower plate in the direction of the lower end,
in which the spacing member further comprises an elastically compressible member tending to maintain the lower plate and the upper plate in a separated position, the connecting member defining a maximum spacing between the lower plate and the upper plate in the position spaced apart, said maximum spacing being greater than said minimum spacing, the elastically compressible member being configured to compress elastically as far as said abutment position of the lower and upper plates against the abutment part in response to a force tending to bring the upper plate closer together of the lower plate.

Thanks to these characteristics, the anchoring device can have a lower stiffness than in the aforementioned prior art in response to a compressive force and thus have a capacity for elastic deformation by crushing between the separated position and the abutment position.

According to other advantageous embodiments, such an anchoring device may have one or more of the following characteristics.

The connecting member which defines the maximum spacing between the lower plate and the upper plate can be made in different ways.

According to one embodiment, the connecting member comprises at least one connecting rod perpendicular to the lower plate and to the upper plate and extending through a bore made in the abutment piece, at least one of the lower plate and the upper plate being mounted in a sliding manner with respect to said connecting rod in order to be able to slide as far as the abutment position.

According to one embodiment, the connecting member further comprises a first stop element coupled to a first end of the connecting rod to longitudinally stop the upper plate with respect to the connecting rod in the separated position.

According to one embodiment, the connecting member further comprises a rotation-blocking element coupled to the first stop element, a portion of the rotation-blocking element being received in a notch that the upper plate has so to block the connecting rod in rotation.

According to one embodiment, the rotation blocking element is housed in a housing that has the upper plate and receiving the first stop element, the notch opening into the housing.

According to one embodiment, the connecting member further comprises a second stop element coupled to a second end of the rod to longitudinally stop the lower plate with respect to the connecting rod in the separated position.

According to one embodiment, the first stop element comprises a nut screwed onto and welded to the first end of the connecting rod, and the second stop element is integral with the lower plate.

According to one embodiment, the second stop element is received in a groove that the lower plate has, the groove comprising two facing faces with which two distinct faces of the second stop element cooperate so as to block the connecting rod in rotation, and the first stop element is integral with the upper plate.

According to one embodiment, the anchoring device also further comprises a spacer part arranged under the lower plate and having a central housing through which the anchor rod passes, the spacer part comprising an upper surface configured to bear against the lower plate of the clamping assembly and a lower surface intended to rest on an insulating block, and the second stop element is received in a groove which the spacer part has, the groove comprising two facing faces with which cooperate two opposite faces of the second stop element so as to block the connecting rod in rotation, and the first stop element is integral with the upper plate.

The elastically compressible member can be arranged in different ways between the lower plate and the upper plate. The elastically compressible member can be mounted in series or in parallel with the abutment piece defining the minimum spacing.

According to one embodiment, the elastically compressible member is engaged on the connecting rod.

According to embodiments, the elastically compressible member bears against the abutment part and/or against at least one of the lower and upper plates.

According to one embodiment, the bore formed in the abutment part has a stage in which the elastically compressible member is arranged. Thanks to these characteristics, the elastically compressible member can have a small size.

The elastically compressible member can be made in different ways. According to one embodiment, the elastically compressible member comprises a stack of elastic washers. For example between 2 and 10 Belleville washers can be used to generate an elastic travel of between 1 and 6 mm.

The elastic movement between the separated position and the abutment position of the upper and lower plates preferably corresponds quite precisely to the movement of a cover plate of the insulating block between a state of rest corresponding to an empty tank and at room temperature and a state service corresponding to the operating conditions of the tank. This displacement is caused by thermal contraction and contraction of the insulating block under load from the pressure exerted by the cargo. It is preferable to consider a differential displacement between the upper surface of the insulating block and the upper surface of the anchoring device by subtracting the contraction of the other parts of the anchoring device under the same conditions. According to one embodiment, the elastic movement is between 1 and 6 mm, preferably 3 mm.

According to one embodiment, the connecting member is configured to exert a static load on the elastically compressible member in the separated position. Such a static load (or preload) makes it possible in particular to ensure reliable support of the overlying sealed membrane during vessel construction operations which are likely to generate localized pressures on the vessel wall (for example drilling operation localized damage to the leaktight membrane, or movement of a worker or tool on the vessel wall under construction). The static load is for example of the order of 1kN.

According to one embodiment, the lower plate has a central hole through which the upper end of the anchor rod passes, and the anchoring device comprises a nut which cooperates with a threaded portion of the upper end of the rod. anchor and one or more elastic washers threaded onto the upper end of the anchor rod between the nut and the lower plate so as to be able to exert an elastic force on the lower plate in the direction of the lower end of the rod anchor.

Preferably in this case, the clamping assembly comprises at least two connecting rods arranged symmetrically with respect to said central bore. Thanks to these characteristics, the forces can be distributed in a balanced way in the clamping assembly.

According to one embodiment, the or each connecting rod is locked in rotation by a spot weld on one or both plates, or by a split lock nut. The split lock nut is placed for example above, below or partially in the lower plate.

According to one embodiment, the anchoring device further comprises a spacer part arranged under the lower plate and having a central housing through which the anchor rod passes, the spacer part comprising an upper surface configured to bear against the plate bottom of the clamping assembly and a bottom surface intended to rest on an insulating block. The spacer piece is for example made of plywood to limit the thermal bridge. The spacer piece preferably has a section identical to the lower plate, of rectangular shape in the embodiments shown. It can be formed from a small number of elongated parts with simple shapes, rigidly assembled together, for example by stapling, screwing and/or gluing. The central housing is preferably filled with thermal insulation around the anchor rod, for example glass wool, wadding, expanded polystyrene or polyurethane foam.

According to one embodiment, the spacer part is formed of four identical elongated profiled parts, one inclined face of which forms a respective wall of the central housing.

According to one embodiment, the spacer piece is formed of two facing plates and two cleats arranged between said two facing plates, each of the two cleats and of the two plates forming a respective wall of the central housing.

According to one embodiment, the thermal insulation comprises a block of glass wool surrounding the anchor rod.

According to one embodiment, the glass wool block has, in its thickness, a notch intended to receive the anchor rod.

According to one embodiment, the block of glass wool comprises at least one sheet of glass fabric, of kraft paper or of polymer, said sheet being placed between the block of glass wool and a wall facing the central housing.

According to one embodiment, the thermal insulation comprises a polymer foam block having a through hole intended to receive the anchor rod.

According to one embodiment, the through hole has a section which widens going from the upper end of the anchor rod towards the lower end of the anchor rod.

According to one embodiment, the spacer part has a blind hole extending in the extension of the connecting rod and capable of receiving part of the connecting rod.

According to one embodiment, the clamping assembly forms a secondary clamping member intended to cooperate with a secondary insulating barrier, the upper plate having a central bore into which is screwed a stud projecting from the clamping assembly at the opposite the anchor rod, said stud carrying a primary clamping member intended to cooperate with a primary insulating barrier.

According to one embodiment, the anchoring device further comprises a sleeve engaged on the lower end of the anchoring rod and intended to be fixed on the bearing wall, the sleeve having a housing receiving the lower end of the anchor rod so as to form a ball joint.

According to one embodiment, the clamping assembly has an overall parallelepipedal shape, the lower plate and the upper plate having a rectangular contour.

According to one embodiment, the anchor rod, the lower plate and the upper plate are made of metal, the abutment piece being made of plywood or another rigid material providing better thermal insulation than metal, for example polyurethane foam with a density greater than 200 kg/m ³ .

According to one embodiment, the invention also provides an anchoring device intended to retain insulating blocks against a load-bearing wall, comprising:
a clamping assembly comprising a lower plate, an upper plate parallel to the lower plate, a connecting member linking the lower plate to the upper plate and a spacing member arranged between the lower plate and the upper plate, the connecting member spacing comprising a rigid abutment part defining a minimum spacing between the lower plate and the upper plate in a position of abutment of the lower and upper plates against the abutment part,
an anchor rod projecting from the clamping assembly perpendicular to the lower plate, the anchor rod comprising a lower end intended to be attached to a load-bearing wall and an upper end opposite the lower end and coupled to the lower plate in order to be able to exert traction on the lower plate in the direction of the lower end, and
a spacer part arranged under the lower plate and having a central housing through which the anchor rod passes, the spacer part comprising an upper surface configured to bear against the lower plate of the clamping assembly and a lower surface intended to lean on an insulating block.

The spacer piece may have one or more of the characteristics already set out above.

According to one embodiment, the invention also provides a sealed and thermally insulating tank for storing a fluid, comprising a supporting wall, anchoring devices fixed to the supporting wall and a tank wall anchored to the supporting wall at with the aid of the anchoring devices, the vessel wall having successively in a direction of thickness, from the outside towards the inside of the vessel, a thermally insulating barrier and a sealing membrane which rests against the thermally insulating,
in which the thermally insulating barrier comprises insulating blocks of parallelepipedal shape which are juxtaposed on the load-bearing wall, a said insulating block comprising a cover plate defining a support surface for the sealing membrane;
in which at least one said aforementioned anchoring device is used, the lower end of the anchoring rod being fixed to the load-bearing wall between a plurality of insulating blocks, the lower plate of the anchoring device cooperating with the plurality of insulating blocks in order to clamp the plurality of insulating blocks in the direction of the load-bearing wall.

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

According to one embodiment, the elastically compressible member is configured to maintain the lower plate and the upper plate in the separated position in an empty state of the tank, the upper plate of the anchoring device in the separated position being aligned with the cover plates of the plurality of insulating blocks to support the waterproofing membrane.

The insulating block can have different structures. According to one embodiment, a said insulating block comprises a bottom plate parallel to and spaced from the cover plate, a fiber-reinforced polymer foam block arranged between the cover plate and a bottom plate and the lower plate of the device anchor cooperates directly or indirectly with said bottom plate without exerting any clamping on the block of polymer foam. For example, the lower plate of the anchoring device can cooperate with the bottom plate by means of a rigid element such as a spacer piece, a pillar and/or a cleat, for example made of plywood.

According to one embodiment, a said insulating block comprises a bottom plate, and successively an intermediate plate and a cover plate parallel to the bottom plate and mutually spaced apart, and two blocks of fiber-reinforced polymer foam arranged respectively between the plate cover plate and the intermediate plate and between the intermediate plate and the bottom plate. The lower plate of the anchoring device cooperates directly with said intermediate plate at the level of a corner zone.

Preferably, the stiffness of the elastically compressible member is smaller than a stiffness in the thickness direction of the insulating barrier adjacent to the anchor device. According to one embodiment, a ratio between the stiffness of the elastically compressible member and a stiffness in the thickness direction of the vessel wall equivalent to a spring consisting of the polymer foam reinforced with fibers having a section equal to that of the upper platinum is between 0.3 and 1.

According to one embodiment, the thermally insulating barrier is a secondary thermally insulating barrier, the insulating blocks are secondary insulating blocks and the sealing membrane is a secondary sealing membrane, the vessel wall further comprising a thermally insulating barrier primary resting against the secondary sealing membrane and a primary sealing membrane which rests against the primary thermally insulating barrier and is intended to be in contact with the fluid contained in the tank; the primary thermally insulating barrier comprising primary insulating blocks which are each superimposed on one of the secondary insulating blocks,
wherein said stud passes through the secondary sealing membrane in leaktight manner and the primary clamping member is held bearing in the direction of the load-bearing wall against a plurality of primary insulating blocks superimposed on said plurality of secondary insulating blocks so as to retain the plurality of primary insulating blocks towards the load-bearing wall.

According to one embodiment, the fluid is a liquefied gas, such as liquefied natural gas, liquefied petroleum gas, liquefied ethylene.

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

According to one embodiment, a vessel for transporting a fluid comprises a double hull and a aforementioned tank placed in the double hull. According to one embodiment, the double shell comprises an inner shell forming the carrier wall of the tank.

According to one embodiment, the invention also provides a transfer system for a fluid, 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 or terrestrial storage installation and a pump for driving a fluid through the insulated pipes from or to the floating or terrestrial storage installation to or from the tank of the ship.

According to one embodiment, the invention also provides a method for loading or unloading such a ship, in which a fluid is routed through insulated pipes from or to a floating or terrestrial storage installation to or from the tank of the ship.

Brief description of figures

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 illustration and not limitation. , with reference to the accompanying drawings.

Figure 1 is a cutaway perspective view of a vessel wall.

Figure 2 is a side view of the vessel wall according to the arrow II of Figure 1, showing the anchoring device in a rest state on the left view and in a compressed state on the right view.

Figure 3 is a side view of an anchor used in the vessel wall of Figure 2, in the rest state.

Figure 4 is a half view similar to Figure 2, showing another embodiment of the anchoring device.

Figure 5A is a sectional view similar to Figure 3, showing yet another embodiment of the anchoring device.

Figure 5B is a sectional view similar to Figure 3, showing yet another embodiment of the anchoring device.

Figure 6A is a perspective and top view showing yet another embodiment of the anchor device.

Figure 6B is a perspective cross-sectional view of the anchor device shown in Figure 6A.

FIG. 7A is a perspective and top view similar to FIG. 6A, showing yet another embodiment of the anchoring device.

FIG. 7B is a perspective and top view showing an alternative rotation-blocking element which can be used in the embodiment represented in FIG. 7A.

Figure 8 is a sectional view similar to Figure 3, showing yet another embodiment of the anchoring device.

Figure 9 is a perspective and bottom view of the anchoring device shown in Figure 8.

Figure 10 is a perspective view of spacer pieces according to three embodiments.

Figure 11 is a perspective view of a spacer piece according to yet another embodiment.

Figure 12 is a perspective view of a heat insulating block that can be received in the central through housing of the spacer pieces shown in Figures 10 and 11.

Figure 13 is a top view of the heat insulating block shown in Figure 12.

Figure 14 is a sectional view, along plane AA of Figure 13, of the thermal insulating block shown in Figures 12 and 13.

Figure 15 is a perspective view of another thermal insulator that can be received in the central through housing of the spacer pieces shown in Figures 10 and 11.

Figure 16 is a sectional view similar to Figure 3, showing yet another embodiment of the anchoring device.

Figure 17 is a partial perspective view from above of the spacer piece of the anchor shown in Figure 16.

Figure 18 is a schematic top view of the vessel wall of Figure 2, showing the position of the anchoring device.

Figure 19 is a perspective view of another insulating block which may be used in the vessel wall of FIG. 1.

Figure 20 is a perspective view of two insulating blocks, one of which is of the type shown in Figure 19, held in place by an anchor device according to yet another embodiment.

Figure 21 is a perspective view of the spacer assembly of the anchor device of Figure 20.

Figure 22 is a cutaway diagrammatic representation of an LNG carrier tank and a loading/unloading terminal for this tank.

By convention, the terms "lower" and "upper" are used to define the relative position of one element in relation to another, respectively in the direction of the outside or the inside of the tank, as in the horizontal wall which is shown in Figure 1. However, the following description is applicable to any wall regardless of its orientation in the gravity field.

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

The load-bearing wall 2 can in particular be formed by the hull or the double hull of a ship. The supporting wall 2 is typically part of a supporting structure comprising a plurality of walls defining the general shape of the tank, usually a polyhedral shape.

The secondary thermally insulating barrier 3 comprises a plurality of secondary insulating blocks 7 which are anchored to the load-bearing wall 2 by means of anchoring devices 20 which will be described in detail later. The secondary insulating blocks 7 have a generally parallelepipedal shape and are arranged in parallel rows.

The secondary sealing membrane 4 comprises a continuous layer of metal strakes 8 with raised edges. The metal strakes 8 are welded by their raised edges to parallel welding supports which are fixed in the grooves 9 made in the cover plates of the secondary insulating blocks 7. The metal strakes 8 are, for example, made of Invar®: c that is to say an alloy of iron and nickel whose coefficient of expansion is typically between 1.2.10 ^-6 and 2.10 ^-6 K ^-1 .

The primary thermally insulating barrier 5 comprises a plurality of primary insulating blocks 11 have a generally parallelepipedic shape and length and width dimensions identical to those of the secondary insulating blocks 7. Each of the primary insulating blocks 11 is positioned opposite one secondary insulating blocks 7, in alignment with the latter along the thickness direction of the vessel wall 1.

The primary sealing membrane 6 can be made in different ways. It comprises here a continuous sheet of metal strakes 8 with raised edges. As in the secondary sealing membrane 4, the metal strakes 8 are welded by their raised edges to parallel welding supports which are fixed in grooves made on the cover plates of the primary insulating blocks 11.

In FIG. 1, a secondary insulating block 7 has been omitted to show shims 12 and beads of mastic 13 intended to compensate for unevenness in the flatness of the bearing wall 2. Positioning shims, not shown, can also be provided as described in publication WO-A-2018069585.

The anchoring devices 20 are preferably positioned at the four corners of the secondary insulating blocks 7 and primary insulating blocks 11. Each stack of a secondary insulating block 7 and of a primary insulating block 11 is anchored to the load-bearing wall 2 by means of four anchoring devices 20. In addition, each anchoring device 20 cooperates with the corners of four adjacent secondary insulating blocks 7 and with the corners of four adjacent primary insulating blocks 11 .

In relation to FIG. 2, the structure of a secondary insulating block 7 according to one embodiment is observed more precisely. The secondary insulating block 7 here comprises a layer of insulating polymer foam 16 sandwiched between a bottom plate 14 and a cover plate 15. The bottom plate 14 and the cover plate 15 are for example made of plywood. The layer of insulating polymer foam 16 is bonded to the bottom plate 14 and the cover plate 15. The insulating polymer foam may in particular be a foam based on polyurethane, optionally reinforced with fibers.

Figure 18 shows more precisely the positioning of an anchoring device 20 between the corners of four adjacent secondary insulating blocks 7 according to one embodiment, in plan view. The anchoring device 20 is represented by the contour of the clamping assembly 30. It can be seen that the bottom plate 14 of each secondary insulating block 7 includes a cutout 52 at the level of its corner zone to release a clearance 55 in rectangular chimney shape which receives the anchoring device 20.

The cover plate 15 and the layer of insulating polymer foam 16 of the secondary insulating block 7 comprise a recess 53 in the shape of a rectangular chimney which uncovers a corner portion 54 of the bottom plate 14. The corner portion 54 is intended to receive directly or indirectly the support of the anchoring device 20, for example via a spacer piece 50 which will be described below or a rigid element integral with the bottom plate 14, such as a pillar of 'angle.

With reference to Figures 2 and 3, we will now describe the structure of an anchoring device 20 according to one embodiment.

The anchoring device 20 essentially comprises a clamping assembly 30 and an anchoring rod 22. The lower end of the anchoring rod 22 is received in a socket 23 whose base is welded to the load-bearing wall 2 in one central position of clearance 55 between the corner zones of four adjacent secondary insulating blocks 7. The sleeve 23 forms a ball joint for the anchor rod 22. For example, it houses a nut 18 into which the lower end of the anchor rod 22 is screwed. The anchor rod 22 extends in the thickness direction of the vessel wall 1 and passes between the primary insulating blocks 22 adjacent.

The clamping assembly 30 comprises successively in the direction of thickness a lower plate 31, a spacer block 33 and an upper plate 32. The lower plate 31 and the upper plate 32 have the general shape of a rectangular parallelepiped comprising two large opposite faces which are parallel to the load-bearing wall 2. The contour of the spacer block 33 is also rectangular and of the same dimension. Alternatively, the outline shape of the clamp assembly 30 could be different, for example hexagonal or circular.

The lower plate 31 is held by the anchor rod 22 bearing in the direction of the load-bearing wall 2 against the corner portion 54 of each of the four adjacent secondary insulating blocks 7. In the embodiment shown, the spacer piece 50 is placed between the lower plate 31 and the corner portion 54 of each of the secondary insulating blocks 7 and thus transmits a clamping force to the bottom plate 14.

The upper end 44 of the anchor rod 22 is engaged through a central bore 41 of the lower plate 31 and in a housing 45 made in the spacer block 33. A nut 42 cooperates with a thread made at the level of the upper end 44 of the anchor rod 22 so as to retain the lower plate 31 in the direction of the load-bearing wall 2.

In the embodiment shown, the anchoring device 20 further comprises one or more spring washers 43, of the Belleville type. The elastic washers 43 are threaded onto the anchoring rod 22 between the nut 42 and the lower plate 31, which makes it possible to ensure an elastic anchoring of the secondary insulating blocks 7 on the bearing wall 2. In addition, advantageously , a locking member is welded locally to the upper end of the anchor rod 22, so as to prevent the unscrewing of the nut 42.

The spacing block 33 further comprises two bores which pass through it in the thickness direction of the vessel wall and in which are engaged two fixing screws 34 which connect the lower plate 31 and the upper plate 32 to two opposite faces. of the spacer block 33. More specifically, the lower end 35 of each fixing screw 34 is threaded and screwed into a tapped hole 38 of the lower plate 31. A split lock nut 37 is also screwed onto the lower end 35 against the upper surface of the lower plate 31, to lock the fixing screws 34 in the lower plate 31 in position. In a manner not shown, the split lock nut 37 can also be placed against the lower surface of the lower plate 31 .

At the opposite end, each fixing screw has a head 36, for example conical, slidably housed in a bore 46 of the upper plate 32. An abutment position of the head 36 against a bottom of the bore 46, shown in Figure 3 and on the left of Figure 2, defines a position of maximum spacing of the plates 32 and 31. The dimension of this maximum spacing is defined by the useful length of the fixing screws 34 between the lower plate 31 and the upper plate 32. This length can be finely adjusted during manufacture, by adjusting the length engaged by screwing into the tapped holes 38.

The spacing block 33 has a lower face and an upper face 48 parallel to the plates 32 and 31. The thickness of the spacing block 33 between the lower face and the upper face 48 defines a minimum spacing between the lower plate 31 and the upper plate 32. This minimum spacing is reached in an abutment position, represented on the right of FIG. 2, in which the lower plate 31 and the upper plate 32 are in abutment against the lower face and the upper face 48 of the block spacing 33.

The dimensional difference between the minimum spacing and the maximum spacing is represented by the arrow 40 and corresponds to a sliding play of the head 36 in the bore 46. Its dimension is determined according to the structure of the wall of the tank and the operating conditions of the tank so that the upper plate 32 can generally follow the depression of the cover plate 15 of the secondary insulating blocks 7 during the operation of the tank, in particular under the effect of the thermal contraction and static and dynamic pressures received by the vessel wall 1 in operation. These pressures can in particular lead to creep of the layer of insulating polymer foam 16. This dimension is typically a few millimeters.

Elastic elements 39, for example Belleville washers, are engaged on the two fastening screws 34 between the spacer block 33 and the upper plate 32 and maintain the plates 32 and 31 in the separated position shown in FIG. 3, in a state of rest. More specifically, the elastic elements 39 create a clearance equal to the dimensional difference 40 between the spacer block 33 and the upper plate 32. In response to a pressure force exerted on the upper plate 32, the Belleville washers 39 compress, erasing gradually this play, until the abutment position of the lower face 49 of the upper plate 32 against the upper face 48 of the spacing block 33.

More precisely, the elastic elements 39 are here housed in a stage 19 of large diameter of the bores receiving the fixing screws 34 and bear against a shoulder at the bottom of the stage 19. In the abutment position, the elastic elements 39 are fully contained in floor 19.

According to one embodiment, each fixing screw 34 carries a stack of Belleville washers arranged successively in mutually inverted positions, preferably in an odd number, for example 5, so that the two ends of the stack consist of the largest Belleville washer diameters.

Preferably, the fixing screws 34 are configured to generate a compression preload on the elastic elements 39 in the rest position, so that the upper plate 32 is able to receive moderate loads without sinking. For example, a preload of approximately 1000N is applied, which makes it possible to support the load of an adult man who could walk in line with the anchoring device 20 during the construction of the vessel.

The stiffness of the elastic elements 39 is determined according to the structure of the vessel wall and the operating conditions of the vessel so that the upper plate 32 can generally follow the depression of the cover plate 15 of the secondary insulating blocks 7 during operation of the vessel, in particular under the effect of thermal contraction and of the static and dynamic pressures received by the vessel wall 1 in operation. These pressures can in particular lead to creep of the layer of insulating polymer foam 16.

It will be noted that the elastic elements 39 can be positioned differently to fulfill the same functions. For example, the fixing screws 34 can be reversed, with the screw head 36 on the side of the lower plate 31 and then positioning the elastic elements 39 between the lower plate 31 and the spacer block 33. In another variant not shown, the spacer block 33 is divided into two parts in the thickness direction and the elastic members 39 are disposed between the two parts.

In another variant illustrated in FIG. 4 in half view, the screw head 36 is positioned in the upper plate 32 and the elastic elements 39 are positioned between the lower plate 31 and the spacer block 33. In this case, the upper plate 32 and spacer block 33 slide together with respect to the fixing screws 34. Furthermore, the rotational stop of the fixing screws 34 with respect to the lower plate 31 can be achieved by a spot weld or a counter-nut, not shown. In Fig. 4 the plates 32 and 31 are shown in the abutment position.

In yet another variant illustrated in FIG. 5A in sectional view, the fixing screws 34 are reversed, with a screw head 36A on the side of the lower plate 31, the elastic elements 39 being for their part always positioned between the plate 32 and the spacer block 33. Stopping the rotation of the fixing screws 34 with respect to the lower plate 31 is here achieved by making the screw heads 36A integral with the lower plate 31, for example by welding, by especially by spot welding. The threaded end 35 of the fixing screws 34 is received in a hole 38A, possibly tapped, that the upper plate 32 has. A counter-nut 37A, preferably not split, is screwed onto this threaded end 35. The counter-nut 37A is additionally welded to the threaded end 35, in particular by spot welding. This prevents jam nut 37A from unscrewing from threaded end 35.

In yet another variant illustrated in FIG. 5B, seen in section, the screw head 36 is replaced by a nut 36B which is threaded on a threaded end 35A. In other words, the fixing screws are replaced by fixing rods 34 which are threaded at their two ends 35 and 35A. The threaded end 35A is screwed into a tapped hole 38A that has the upper plate 32. The threaded end 35 is itself screwed into the hole 38, possibly tapped, that has the lower plate 31. fixing 34 with respect to the upper plate 32 is also made by making the nuts 36B integral with the upper plate 32, for example by welding, in particular by spot welding. A stop in rotation of the fixing rods 34 with respect to the lower plate 31 can be achieved in addition by making the threaded end 35 integral with the lower plate 31, for example by welding, in particular by spot welding.

FIG. 6A shows in perspective view and from above yet another variant, which appears in perspective section in FIG. 6B. In this variant, the fixing screws 34 are stopped in rotation by an elongated bar 90 coupled to the screw head 36. The bar 90 is received in two opposite notches 91A and 91B opening into the bore 46. The cooperation between the bar 90 and these notches 91A and 91B blocks the corresponding fastening screw 34 in rotation with respect to the upper plate 32. The bar 90 can for example be metallic. The fixing of the bar 90 to the screw head 36 can be carried out by clipping, by spot welding, or by forcibly pushing the bar 90 into a housing (not shown) carried by the screw head 36. threaded lower end 35 of the fixing screw 34 can simply be screwed into the tapped hole 38 of the lower plate 31, without counter-nut or spot weld.

FIG. 7A shows in perspective and top view another variant which is similar to that of FIGS. 6A and 6B, except that the bar 90 cooperates with a single notch 91 opening into the bore 46. The notch 91 can lead to a side face of the upper plate 32 as shown in Figure 7A, but alternatively, the notch 91 may not lead to this side face.

There is shown in Figure 7B a rotation blocking element 90C that can be used to replace the strip 90. This element 90C is of the key type, that is to say it comprises a central washer 90C2 from which extends a tongue 90C1. The tab 90C1 is received in the notch 91 and thus blocks the corresponding fixing screw 34 in rotation with respect to the upper plate 32. The central washer 90C2 is housed in the bore 46. The fixing of the central washer 90C2 to the screw head 36 can be made by clipping, by spot welding, or by forcibly pushing the bar 90 into a housing (not shown) carried by the screw head 36. In a variant not shown, the element 90C can present two opposite tongues, respectively received in the notches 91A and 91B.

There is shown in section in Figure 8 and in perspective view from below in Figure 9 yet another variant. In this variant, a lock nut 37B, preferably not split, is screwed onto the lower threaded end 35 of the fixing screw 34. The lock nut 37B is received in a groove 92 that the lower plate 31 has and in which the hole 38, optionally tapped, opens. Groove 92 opens onto the underside of lower plate 31. Groove 92 has two opposite faces with which two separate faces of counter-nut 37B cooperate. This cooperation blocks the fixing screw 34 in rotation with respect to the lower plate 31. In the example shown in the figures, the counter-nut 37B is a square nut. However, the counter-nut 37B can also be of another shape as long as it has two distinct faces which can cooperate with two faces facing the groove 92. In particular, the counter-nut 37B can be of hexagonal shape, two adjacent faces of the hexagon then cooperating with two faces opposite the groove 92. A stop in rotation of the fixing screws 34 with respect to the upper plate 32 is also achieved by making the screw heads 36 integral with the upper plate 32, for example by welding, in particular by spot welding. The groove 92 may open onto a side face of the lower plate 31 as shown in Figures 8 and 9, but alternatively, the groove 92 may not open onto this side face.

We also see in Figure 8 that the spacer piece 350 has a blind hole 60 extending in the extension of each fixing screw 34 as will be detailed later.

The tank wall 1 could be limited to the secondary insulating barrier 3 and the secondary sealed membrane 4 to produce a simple membrane tank. In the case where the primary insulating barrier 5 and the primary waterproof membrane 6 are present, the anchoring device 20 also comprises a primary stage. For this, the upper plate 32 has a threaded bore 47 in its center, in which is mounted a threaded base of a stud 27 intended for anchoring the primary insulating blocks 11. The stud 27 passes through a bore made through a metal strake 8 of the secondary waterproof membrane 4. The stud 27 has a flange which is welded to its periphery, around the hole, to ensure the tightness of the secondary waterproof membrane 4.

The primary stage of the anchoring device 20 also comprises a primary bearing plate 28 which rests in the direction of the load-bearing wall 2 on a bearing zone formed in each of the four adjacent primary insulating blocks 11 so as to hold against the secondary waterproof membrane 4. In the embodiment shown, each support zone 29 is formed by an overhanging part of a bottom plate of the primary insulating block 11.

A nut 29 cooperates with a thread provided at the upper end of the pin 27 so as to ensure the fixing of the primary support plate 28 on the pin 27. In the embodiment shown, the anchoring device 20 further comprises a Belleville-type elastic washer threaded onto the stud 27 between the nut 28 and the primary bearing plate 28, which ensures elastic anchoring of the primary insulating blocks 11 on the secondary sealed membrane 4.

FIG. 10 illustrates several embodiments of a spacer piece 50, 150 or 250 of the anchoring device 20, which each time has a central through housing 51 to let the anchor rod 22 pass, an end surface upper 56 to receive the support of the lower plate 31 and a lower end surface 57 to exert a support on the secondary insulating block. The spacer piece 50, 150 or 250 is for example made of plywood to limit the thermal bridge. The spacer piece 50, 150 or 250 preferably has a section identical to the lower plate 3, of rectangular shape in the embodiments shown. It can be formed from a small number of elongated parts with simple shapes, rigidly assembled together, for example by stapling, screwing and/or gluing.

Not shown, the central through housing 51 is filled with thermal insulation around the anchor rod 22, for example glass wool, wadding, expanded polystyrene or polyurethane foam.

The spacer piece 50 or 250 is formed of two flat rectangular plates 58 forming the main faces of the spacer piece and two cleats 59 arranged between the two flat rectangular plates along the edges thereof. Each of the four parts thus forms a wall of the central through housing 51, which has a square or rectangular section.

The spacer piece 150 is formed of four identical profiled elongated pieces having a section in the shape of a rectangular trapezium, an inclined face of which forms a respective wall of the central through housing 51, which has a section in the shape of a diamond. To limit the thermal bridge, longitudinal cells are formed on either side of the central through housing 51 and also filled with an insulating material.

FIG. 11 illustrates yet another embodiment of a spacer piece 350. This spacer piece 350 is identical to the spacer piece 250 except that each cleat 59 has a blind hole 60, each blind hole 60 being intended to come into the extension of a fixing screw 34 so as to be able to receive part of this fixing screw 34. In another variant not shown, the spacer part 50 can also have such blind holes 60. In the spacer part 150, the longitudinal cells formed on either side of the central through housing 51 can only be partially filled with the insulating material, so that the insulating material and the longitudinal cells together form blind holes similar to blind holes 60.

Figures 12 to 14 together illustrate an embodiment of a block of thermal insulation 451 that can be received in the central through housing 51. The block of thermal insulation 451 has an external shape complementary to the central through housing 51, here a parallelepiped outer shape. The thermal insulation block 451 is here made of a thermally insulating polymer foam. The polymer foam can be of low density, that is to say a density comprised between 10 kg/m ³ and 60 kg/m ³ , more particularly comprised between 10 kg/m ³ and 30 kg/m ³ . The polymer foam can be a polyurethane foam or else a melamine foam, in particular a melamine foam from the family of foams marketed by the company BASF SE under the name Basotect®. The polymer foam can optionally be reinforced with fibers, for example glass fibers.

It is further seen in Figures 12 to 14 that the thermal insulation block 451 has a through hole 452. The through hole 452 is intended to receive the anchor rod 22 when the spacer piece is arranged under the clamping assembly 30 as previously described. As can be seen in FIG. 14, the through-hole 452 has a section which widens going from the upper end of the anchor rod 22 towards the lower end of the anchor rod 22. In particular, this can be obtained by giving the through-hole 452 a frustoconical section as shown in FIG. of the anchor rod 22, it being indicated that this installation is carried out when the anchor rod 22 is already fixed to the load-bearing wall 2 by the sleeve 23 and the nut 18. In addition, this widening makes it possible to offer a certain clearance in which the anchor rod 22 is free to move due to the ball joint formed by the sleeve 23.

FIG. 15 illustrates another exemplary embodiment of a block of thermal insulation 551 that can be received in the central through housing 51. The block of thermal insulation 551 has an outer shape complementary to the central through housing 51, here parallelepipedal. The thermal insulation block 551 is here made of glass wool. It may possibly consist of two sub-blocks 552 of glass wool joined together. The block of thermal insulation 551 surrounds the anchor rod 22 (not shown in Figure 15) when the spacer piece is disposed under the clamp assembly 30 as previously described. To do this, the thermal insulation block 551 may have a notch 554 in its thickness which extends parallel to the anchoring rod 22. The notch 554 allows the anchoring rod 22 to pass through the block. of thermal insulation 551 while allowing the elastic return of the glass wool to enclose the anchor rod 22 once the latter has passed through the block of thermal insulation 551. The block of thermal insulation 551 can also be made in the same way with cellulose or polyester wadding.

It can also be seen in FIG. 15 that sheets 555 can be arranged on two opposite faces of the block of thermal insulation 551, more particularly the two largest faces of the block of thermal insulation 551 which face the two largest faces of the central through housing 51. The sheets 555 can be made of glass fabric, kraft paper or even a polymer such as PVC. The sheets 555 make it possible to facilitate the sliding of the block of thermal insulation 551 on the faces of the central through housing 51 when the block of thermal insulation 551 is inserted into the central through housing 51. Alternatively, only one of the sheets 555 may be present , and/or additional sheets, not shown, can be added to the faces of the thermal insulation block 551 which are not covered by the sheets 555.

There is shown in Figures 16 and 17 yet another variant of a spacer piece together with the clamp assembly 30, Figure 16 being a sectional view and Figure 17 being a partial perspective view from above the spacer piece. In this variant, as in the variant of FIGS. 8 and 9, a lock nut 37B, preferably not split, is screwed onto the threaded lower end 35 of the fixing screw 34. The lock nut 37B is received in a groove 660 presented by the spacer piece 650. The spacer piece 650 is here formed, like the spacer piece 250, of two flat rectangular plates 58 forming the main faces of the spacer piece 650 and two cleats 59 arranged between the two flat rectangular plates 58 along their edges. A groove 660 is formed in each of the two cleats 59. The groove 660 has two facing faces with which two separate faces of the counter-nut 37B cooperate. This cooperation blocks the fixing screw 34 in rotation with respect to the lower plate 31. In the example shown in the figures, the counter-nut 37B is a square nut. However, the counter-nut 37B can also be of another shape as long as it has two distinct faces which can cooperate with two faces facing the groove 660. In particular, the counter-nut 37B can be of hexagonal shape, two opposite faces of the hexagon then cooperating with two faces opposite the groove 660. A stop in rotation of the fixing screws 34 relative to the upper plate 32 is also achieved by making the screw heads 36 integral with the upper plate 32, for example by welding, in particular by spot welding.

Sizing example

Due to the stiffness of the elastic elements 39, the clamping assembly 30 is in the separated position corresponding to the maximum spacing when the tank is empty and at room temperature, that is to say under the conditions of its construction. initial. In this state, the position of the upper platen 32 is adjusted to be aligned with the cover plate 15, so as to provide a uniform support surface for the secondary waterproof membrane 4.

During operation of the vessel, following the filling of the vessel with liquefied gas, phenomena of thermal contraction and contraction and creep under the hydrostatic load will occur in the secondary insulating barrier 3.

The thermal contractions are not identical in all materials and the layers of insulating polymer foam 16 tend to contract more than the plywood constituting the spacer piece 50 and the spacer block 33. In addition, the pressure loads are different depending on the position of the tank wall at the bottom, on the ceiling or on the sides. All the walls receive at least the service pressure of the vapor phase, which is for example 2 kPa or 5 kPa (20 or 50 mbar).

The stiffness of the elastic elements 39 can be dimensioned so that, after cooling and under the operating pressure of the vapor phase, the elastic compression of the elastic elements 39 allows an additional lowering of the upper plate 32 which is greater than or equal to the increased contraction and creep of the secondary insulating blocks 7 relative to the thermal contraction of the anchoring device 20. This increased contraction and creep of the secondary insulating blocks 7 is for example approximately 1 mm under the service pressure of the vapor phase. Thus the upper plate 32 follows the level of the cover plates 15 and does not risk generating a protruding zone liable to shear the secondary waterproof membrane 6.

The stiffness of the elastic elements 39 and the dimension of the gap 40 can also be dimensioned so that the clamping assembly 30 reaches the stop position, corresponding to the minimum spacing under the following conditions:
- either under hydrostatic loading, when the overlying primary insulating block receives maximum cargo pressure;
- or under dynamic loading, when the overlying primary insulating block receives an impact pressure due to the sloshing of the cargo exceeding a predetermined nominal threshold.

In all cases, the elastic elements 39 increase the flexibility of the anchoring device 20 and thus limit the risk of locally forming a hard point or a protruding zone which could accelerate the aging of the secondary waterproof membrane 6.

Preferably, the total stiffness of the elastic member acting between the two plates, namely here the elastic elements 39, is less than the equivalent stiffness of the thermally insulating barrier at the service temperature in the immediate vicinity of the anchoring device . In the illustrated embodiment, it is the layer of insulating polymer foam 16 which controls the stiffness of the thermally insulating barrier. In one embodiment, the total stiffness of the elastic elements 39 is approximately 1880N/mm, while the stiffness in the thickness direction of the vessel wall is equivalent to a spring consisting of the insulating polymer foam 16 having a section equal to that of the upper plate is approximately 1920N/mm, ie a stiffness ratio equal to 0.98. More generally, this ratio could be chosen between 0.3 and 1.

The structure of the secondary insulating block 7 is described above by way of example. Also, in another embodiment, the secondary insulating blocks 7 are likely to have another general structure, for example that described in document WO-A-2012127141. The secondary insulating blocks 7 are then made in the form of a box comprising a bottom plate, a cover plate and supporting webs extending, in the direction of thickness of the wall 1 of the vessel, between the bottom plate and the cover plate and delimiting a plurality of compartments filled with an insulating filling, such as perlite, glass or rock wool.

Another embodiment of the secondary insulating blocks is illustrated in Figure 19 at numeral 107. In Figure 19, elements similar or identical to those of the preceding figures bear the same reference numeral increased by 100 and are not described again. . The layer of insulating polymer foam is here divided into two lower and upper layers 16b and 16a separated by an intermediate plate 10, for example made of plywood, glued to them. The length of the upper layer 16a is smaller than the length of the lower layer 16b and uncovers a flange 10a at two longitudinal ends of the intermediate plate 10.

A rigid pillar 17 extends in the thickness direction of the lower layer 16b between the intermediate plate 10 and the bottom plate 114, in recesses provided at the four corners of the lower layer 16b. The rigid pillar 17 is partially plumb with the flanges 10a to take up the tightening force of the anchoring device 20, the lower plain 31 of which can here be applied directly to the flange 10a. Further details of the secondary insulating block 107 can be found in the publication WO-A-2014096600.

With reference to FIGS. 20 and 21, a description will now be given of a variant of the anchoring device which is useful for retaining on the load-bearing wall 2 two secondary insulating blocks 107 which are adjacent to two secondary insulating blocks 7. A transition of the secondary insulating blocks 107 to the secondary insulating blocks 7 can in particular be used as described in WO-A-2019077253, for example in the vicinity of an edge of the bearing wall 2.

In FIG. 20, a secondary insulating block 107 and a secondary insulating block 7 have thus been shown in perspective, the other two secondary insulating blocks not being shown to allow the anchoring device 220 to be seen. Anchor 220 which are similar to those of anchor 20 bear the same reference numerals and are not described again.

It can be seen in FIG. 20 that, on the side of the secondary insulating block 107, the lower plate 31 rests on the intermediate plate 10, while on the side of the secondary insulating block 7, the lower plate 31 rests on a wedge 280 received at the corner zone 54, via a spacer portion 750 which will be described. It is understood that on the side of the secondary insulating block 107, the anchoring device 220 should fill the space between the intermediate plate 10 and the bottom plate 114. However, since the lower plate 31 rests on the intermediate plate 10, the part of the anchoring device 220 which fills this space does not need to resist forces as great as those transmitted by the spacer portion 750. Also, this space is occupied by a portion of spacer 760 less dense which will be described.

In summary, still referring to Figure 20, under the lower plate 31, the anchoring device 220 comprises a spacer assembly 700 comprising the spacer portion 750 on the side of the insulating block 7, and the spacer portion 760 on the side of the insulating block 107.

In FIG. 21, only the spacer assembly 700 has been shown in perspective.

As can be seen in this figure, the spacer portion 750 has an upper end surface 756 to receive support from the lower plate 31 and a lower end surface 757 to exert support on the wedge 280 of the block. secondary insulation 7. The spacer portion 750 is for example made of plywood to limit the thermal bridge.

The spacer portion 750 is formed of two flat rectangular plates 758 forming the main faces of the spacer portion 750 and of a bracket 759 disposed between the two flat rectangular plates 758 along the edges thereof. It can also be seen in FIG. 21 that the cleat 759 may have a blind hole 751 intended to come in the extension of one of the fixing screws 34 of the clamping assembly 30 so as to be able to receive part of this fixing screw. fixing 34.

The spacer portion 760 has for its part a central portion 761 having a through hole 762 through which the anchor rod 22 passes. The lower plate 31 can rest on the upper surface 766 of this central portion 761.

In addition, a tongue 765 protrudes from the central portion 761 towards the spacer portion 750 and is received in a housing of complementary section formed by the plates 758 and the cleat 759 of the spacer portion 750. The tongue 765 can be forced into this housing, or glued and/or stapled and/or screwed to the plates 758.

In addition, the spacer portion 760 may have a wing 770 projecting from the central portion 761 in a direction opposite to the spacer portion 750. As can be seen in FIG. 15, this wing 770 may rest on the side faces opposite the insulating blocks 107.

As mentioned above, the space occupied by the spacer portion 760 does not need to resist forces as great as those transmitted by the spacer portion 750. Also, the spacer portion 760 is made of a polymer foam, which is thermally insulating to limit the thermal bridge. The polymer foam can be of low density, that is to say a density comprised between 10 kg/m ³ and 60 kg/m ³ , more particularly comprised between 10 kg/m ³ and 30 kg/m ³ . The polymer foam can be a polyurethane foam or else a melamine foam, in particular a melamine foam from the family of foams marketed by the company BASF SE under the name Basotect®. The polymer foam can optionally be reinforced with fibers, for example glass fibers. Alternatively to polymer foam, the use of polystyrene is also possible as insulation.

The primary insulating block 11 can be made in different ways, for example in the form of a layer of insulating polymer foam sandwiched between a bottom plate and a cover plate like the secondary insulating block 7.

The bottom plate then has grooves intended to receive the raised edges of the strakes 8 of the secondary sealing membrane 4. The cover plate also has grooves to receive welding supports.

The structure of the primary insulating panel 11 is described above by way of example. Also, in another embodiment, the primary insulating panels 22 are likely to have another general structure, for example that described in document WO-A-2012127141.

The technique described above for producing a tank wall having a single or two leaktight membranes can also be used in different types of tanks, for example to form a double membrane tank for liquefied natural gas (LNG) in an onshore installation or in a floating structure such as an LNG carrier or other.

Referring to Figure 22, 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 leaktight barrier intended to be in contact with the LNG contained in the tank, a secondary leaktight barrier arranged between the primary leaktight 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 hull 72.

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

FIG. 22 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 off-shore installation comprising an 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 installation on land 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 set out in a claim.

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

Claims (25)

Anchoring device (20) intended to retain insulating blocks against a load-bearing wall, comprising:
a clamping assembly (30) comprising a lower plate (31), an upper plate (32) parallel to the lower plate, a connecting member (34) linking the lower plate to the upper plate and a spacing member arranged between the lower platen and the upper platen, the spacing member comprising a rigid abutment part (33) defining a minimum spacing between the lower platen and the upper platen in a position of abutment of the lower and upper plates against the abutment part , And
an anchor rod (22) projecting from the clamp assembly perpendicular to the lower plate (31), the anchor rod having a lower end intended to be attached to a load-bearing wall (2) and an opposite upper end at the lower end and coupled to the lower plate (31) to be able to exert traction on the lower plate in the direction of the lower end,
wherein the spacing member further comprises an elastically compressible member (39) tending to maintain the lower plate and the upper plate (32) in a separated position, the connecting member defining a maximum spacing between the lower plate and the upper plate in the separated position, said maximum spacing being greater than said minimum spacing, the elastically compressible member (39) being configured to compress elastically up to said abutment position of the lower and upper plates (31, 32) against the stop piece (33) in response to a force tending to bring the upper plate closer to the lower plate. Anchoring device according to Claim 1, in which the connecting member comprises at least one connecting rod (34) perpendicular to the lower plate and to the upper plate and extending through a bore made in the abutment part , at least one of the lower plate and the upper plate being slidably mounted relative to said connecting rod to be able to slide to the stop position. Anchoring device according to Claim 2, in which the connecting member further comprises a first stop element (36, 37A, 36B) coupled to a first end of the connecting rod for longitudinally stopping the upper plate (32 ) relative to the connecting rod in the separated position. Anchor according to claim 3, wherein the first stop member includes a nut (36B) screwed onto and welded to the first end of the link rod (34), and wherein a second end of the link (34) is integral with the lower plate (31). Anchoring device according to claim 3, in which the connecting member further comprises a rotation blocking element (90, 90C) coupled to the first stop element (36), a portion of the blocking element in rotation (90, 90C) being received in a notch (91, 91A, 91B) presented by the upper plate (32) so as to lock the connecting rod (34) in rotation. An anchor according to claim 2 or 3, wherein the link member further comprises a second stop member (37, 38, 36A, 38A, 37B) coupled to a second end of the link rod to stop longitudinally the lower plate (31) relative to the connecting rod in the separated position. Anchoring device according to Claims 3 and 6 taken in combination, in which the first stop element comprises a nut (37A) screwed onto and welded to the first end of the connecting rod (34), and in which the second stop element (36A) is integral with the lower plate (31). Anchoring device according to Claims 3 and 6, in which the second stop element (37B) is received in a groove (92) which the lower plate (31) has, the groove (92) comprising two facing faces with which cooperate two distinct faces of the second stop element (37B) so as to block the connecting rod (34) in rotation, and in which the first stop element (36) is integral with the upper plate (32). Anchoring device according to claims 3 and 6, further comprising a spacer piece (650) arranged under the lower plate and having a central housing (51) through which the anchor rod passes, the spacer piece comprising an upper surface (56 ) configured to bear against the lower plate of the clamping assembly and a lower surface (57) intended to bear against an insulating block, and in which the second stop element (37B) is received in a groove (660) presented by the spacer piece (650), the groove comprising two facing faces with which two opposite faces of the second stop element (37B) cooperate so as to block the connecting rod (34) in rotation, and in which the first stop element (36) is integral with the upper plate (32). Anchoring device according to one of Claims 2 to 9, in which the elastically compressible member (39) is engaged on the connecting rod (34). Anchoring device according to one of Claims 2 to 10, in which the elastically compressible member (39) bears against the abutment piece. Anchoring device according to Claim 11, in which the bore made in the abutment part has a stage (19) in which the elastically compressible member (39) is arranged. Anchoring device according to one of Claims 1 to 12, in which the elastically compressible member (39) comprises a stack of spring washers. Anchoring device according to one of Claims 1 to 13, in which the elastic displacement between the separated position and the abutment position of the upper and lower plates (31, 32) is between 1 and 6 mm. Anchoring device according to one of Claims 1 to 14, in which the lower plate (31) has a central bore (41) through which the upper end of the anchoring rod (22) passes, in which the device for anchor comprises a nut (42) which cooperates with a threaded portion of the upper end of the anchor rod and one or more spring washers (43) threaded onto the upper end of the anchor rod between the nut and the lower plate so as to be able to exert an elastic force on the lower plate in the direction of the lower end of the anchor rod. Anchoring device according to Claim 15 taken in combination with Claim 2, in which the clamping assembly (30) comprises at least two connecting rods (34) arranged symmetrically with respect to the said central bore (41). Anchoring device according to one of Claims 1 to 16, comprising a spacer piece (50, 150, 250, 350, 650) arranged under the lower plate and having a central housing (51) through which the anchor rod passes, the spacer piece comprising an upper surface (56) configured to bear against the lower plate of the clamping assembly and a lower surface (57) intended to bear against an insulating block. Anchoring device according to one of Claims 1 to 17, further comprising a sleeve (23) engaged on the lower end of the anchoring rod and intended to be fixed on the bearing wall (2), the sleeve having a housing receiving the lower end of the anchor rod (22) so as to form a ball joint. Sealed and thermally insulating tank for storing a fluid, comprising a supporting wall, anchoring devices (20) fixed to the supporting wall (2) and a tank wall (1) anchored to the supporting wall using of said anchoring devices, the tank wall (1) successively presenting in a direction of thickness, from the outside towards the inside of the tank, a thermally insulating barrier (3) and a sealing membrane (4) which rests against the thermally insulating barrier (3),
wherein the thermally insulating barrier (3) comprises insulating blocks (7) of parallelepipedal shape which are juxtaposed on the load-bearing wall (2), a said insulating block comprising a cover plate defining a support surface for the sealing membrane (4);
wherein at least one said anchoring device is according to one of claims 1 to 18, the lower end of the anchor rod (22) being fixed to the load-bearing wall between a plurality of insulating blocks (7), the lower plate (31) of the anchoring device cooperating with the plurality of insulating blocks (7, 107) in order to tighten the plurality of insulating blocks in the direction of the load-bearing wall (2). Tank according to claim 19, in which the elastically compressible member (39) is configured to maintain the lower platen and the upper platen in the separated position in an empty state of the tank, the upper platen (32) of the anchoring device in the spaced apart position being aligned with the cover plates of the plurality of insulating blocks to support the sealing membrane (4). A tank according to claim 19 or 20, wherein a said insulating block comprises a bottom plate (14) parallel to and spaced from the cover plate (15), a fiber reinforced polymer foam block (16) arranged between the cover and a bottom plate and in which the lower plate of the anchoring device cooperates directly or indirectly with said bottom plate (14) without exerting any clamping on the polymer foam block (16). Tank according to Claim 19 or 20, in which a said insulating block (107) comprises a bottom plate (114), and successively an intermediate plate (10) and a cover plate (115) parallel to the bottom plate and mutually spaced apart, and two blocks of fiber-reinforced polymer foam (16a, 16b) arranged respectively between the cover plate and the intermediate plate and between the intermediate plate and the bottom plate, in which the lower plate (31) of the device anchor cooperates directly with said intermediate plate (10) at a corner zone. A tank according to claim 19 or 20, wherein a ratio between the stiffness of the elastically compressible member and a stiffness in the thickness direction of the tank wall equivalent to a spring made of the fiber-reinforced polymer foam having a section equal to that of the upper plate is between 0.3 and 1. Tank according to any one of Claims 19 to 23, in which the thermally insulating barrier is a secondary thermally insulating barrier (3), the insulating blocks are secondary insulating blocks (7) and the sealing membrane is a membrane of secondary sealing (4), the vessel wall further comprising a primary thermally insulating barrier (5) resting against the secondary sealing membrane (4) and a primary sealing membrane (6) which rests against the primary thermally insulating barrier (5) and is intended to be in contact with the fluid contained in the tank; the primary thermally insulating barrier (5) comprising primary insulating blocks (11) which are each superimposed on one of the secondary insulating blocks (7),
wherein the clamping assembly (30) forms a secondary clamping member intended to cooperate with the secondary insulating barrier, the upper plate (32) having a central bore (47) into which is screwed a stud (27) projecting from the clamping assembly opposite the anchor rod, said stud (27) carrying a primary clamping member (28) intended to cooperate with the primary insulating barrier (5), and in which said stud (27) passes through the secondary sealing membrane (4) in leaktight manner and the primary clamping member is held bearing in the direction of the load-bearing wall (2) against a plurality of primary insulating blocks (11) superposed on said plurality of insulating blocks secondary so as to retain the plurality of primary insulating blocks towards the load-bearing wall (2). Vessel (70) for the transport of a fluid, the vessel comprising a double hull (72) and a tank (71) according to any one of claims 19 to 24 arranged in the double hull (72).