FR3143096A1 - Anchoring device for a thermally insulating block - Google Patents

Abstract

The invention relates to an anchoring device (20) comprising: a clamping assembly comprising a lower plate, an upper plate, a connecting member and a spacer member, an anchor rod engaged in an opening in the plate lower and projecting from the clamping assembly through the opening of the lower plate, the anchor rod comprising a lower end portion and an upper end portion located between the lower plate and the upper plate, a screwed nut on the upper end portion of the anchor rod located between the lower plate and the upper plate, the upper end portion has an upper end comprising a first recess intended to serve as a gripping area for a first tool screwing intended to rotate the anchor rod, the upper plate having a first orifice located opposite the first cavity in order to form a passage for the first screwing tool. Figure for the abstract: 1

Description

Anchoring device for a thermally insulating block

The invention relates to the field of waterproof and thermally insulating membrane tanks. In particular, the invention relates to the field of sealed and thermally insulating tanks for the storage and/or transport of liquefied gas at low temperature, such as tanks for transport for the transport of Liquefied Natural Gas (LNG) at approximately -163°C at atmospheric pressure, and in particular to a mechanical anchoring device usable in such a tank. These tanks can be installed on land or on a floating structure.

Technology background

We know, for example from documents WO2014096600A1 and WO2019110894A1, a sealed and thermally insulating tank for storing liquefied natural gas arranged in a supporting structure and whose walls have a multi-layer structure, namely from the outside towards the inside of the tank, a secondary thermally insulating barrier anchored against the supporting structure, a secondary waterproofing membrane which is supported by the secondary thermally insulating barrier, a primary thermally insulating barrier which is supported by the secondary waterproofing membrane and a waterproofing membrane primary 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 waterproofing 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 supporting structure.

Certain aspects of the invention are based on the observation that the assembly of an anchoring device intended to retain thermally insulating blocks against a supporting wall of a tank as mentioned above involves numerous assembly steps to be carried out in situ, during the manufacturing of such a tank.

An idea underlying the invention is to provide an anchoring device making it possible to reduce and facilitate the in situ assembly steps during the manufacture of a waterproof and thermally insulating tank.

According to one embodiment, the invention provides an anchoring device intended to retain a thermally insulating block against a supporting wall, the anchoring device 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,
an anchor rod engaged in a through opening of the lower plate and projecting from the clamping assembly through the through opening of the lower plate, the anchor rod comprising a threaded lower end portion intended to be fixed to the supporting wall and a threaded upper end portion opposite the lower end portion and located between the lower plate and the upper plate,
a nut screwed onto the upper end portion of the anchor rod located between the lower plate and the upper plate, the nut engaging the anchor rod with an upper surface of the lower plate so as to be able to exert a restoring force on the lower plate in the direction of the lower end portion, in which the upper end portion has an upper end comprising a first recess intended to serve as a gripping zone for a first screwdriving tool intended to make turn the anchor rod relative to the clamping assembly to screw the lower end portion of the anchor rod to the supporting wall, the upper plate having a first through hole located opposite the first impression in order to form a passage for the first screwing tool.

Thanks to these characteristics, it is possible to mount such an anchoring device quickly and easily during the manufacture of a waterproof and thermally insulating tank. In fact, the anchor rod can be screwed directly by passing a screwdriving tool directly through the hole in the upper plate. In addition, the assembly of such an anchoring device can be carried out essentially by prefabrication outside the tank unlike current practice where all the elements of the anchoring device are assembled in the tank.

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

According to one embodiment, the nut has a nut head surmounting the upper end of the anchor rod, the nut head having a through passage located between the upper plate and the upper end of the rod. anchoring in alignment with the first through hole and the first cavity to allow the first screwdriving tool to pass to the first cavity, the nut head having a second cavity intended to serve as a gripping area for a second tool screwing intended to rotate the nut relative to the anchor rod, the first through hole being located opposite the second cavity so as to form a passage for the second screwing tools.

Thanks to these characteristics, it is possible to screw the anchor rod and the nut directly through the hole in the upper plate by inserting one or more suitable screwing tools.

According to one embodiment, a shape of the first impression and/or the second impression is chosen from: flat, slotted, cruciform, Pozidriv, star, hollow hexagonal, hollow, square, internal, external and internal hexalobular. Preferably an internal hexalobular shape approved ISO 10664 can be used.

The shape of the impression can be chosen according to the needs of the intended application depending on the efficiency in tightening, the holding of the tool, the wear of the tip, the good transmission of the tightening torque.

According to one embodiment, the second imprint is formed by a peripheral wall of the through passage of the nut head.

According to one embodiment, the first tool and/or the second tool is chosen from: a screwdriver, a screwdriver and a male or female key.

According to one embodiment, the first through hole has a diameter greater than 10 mm, preferably greater than 15 mm, for example between 15 and 20 mm.

According to one embodiment, the anchoring device comprises an anti-rotation plate arranged between the nut and the upper plate and intended to be fixed to the nut so as to block the rotation of the nut.

According to one embodiment, the upper plate is fixed to the nut so as to block the rotation of the nut.

According to one embodiment, the anti-rotation plate has a generally rectangular shape.

According to one embodiment, the anti-rotation plate is metallic.

According to one embodiment, the anti-rotation plate is arranged near the spacer member so as to be blocked in abutment against the spacer member when the anti-rotation plate is rotated in the clockwise direction or counterclockwise.

According to one embodiment, the anchoring device comprises at least one spring element surrounding the anchor rod is located between the nut and the lower plate, preferably at least one spring element comprises a stack of Belleville washers.

According to one embodiment, the Belleville washers forming the stack of Belleville washers have identical or different dimensions.

According to one embodiment, the stack of Belleville washers comprises at least a first and a second Belleville washer, the first Belleville washer of which has dimensions smaller than the second Belleville washer.

According to one embodiment, the stack of Belleville washers comprises a first Belleville washer and a second Belleville washer reversed relative to the first Belleville washer.

According to one embodiment, the stack of Belleville washers comprises between 2 and 7 Belleville washers.

According to one embodiment, the spacer member comprises a stop part defining a spacing between the lower plate and the upper plate, the lower and upper plates abutting against opposite surfaces of the stop part.

According to one embodiment, the spacer member comprises a stop 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 stop part, the stop part comprising a rigid part, the spacer member further comprising an elastically compressible member tending to maintain the lower plate and the upper plate in a spaced position, the connecting member defining a maximum spacing between the lower plate and the upper plate in the spaced position, said maximum spacing being greater than said minimum spacing, the elastically compressible member being configured to compress elastically up to said abutment position of the lower and upper plates against the abutment piece in response to a force tending to bring the upper plate from the lower plate.

According to one embodiment, the stop part comprises a first rigid part and a second rigid part mutually spaced apart, the upper end portion of the anchor rod and the nut being located between the first rigid part and the second rigid part.

According to one embodiment, the first rigid part and the second rigid part have a general shape of a rectangular parallelepiped.

According to one embodiment, the first rigid part and the second rigid part have the same dimensions.

According to one embodiment, the stop part further comprises two through bores in which two fixing screws are engaged which connect the lower plate and the upper plate to two opposite faces of the stop part, each screw head being housed and retained respectively in a second and third through hole of the upper plate, and each threaded end of the screw being housed in a first and a second tapped holes provided in the lower plate.

According to one embodiment, the anchoring device further comprises a socket intended to be fixed to the supporting wall, and a nut housed in the socket so as to be blocked in rotation in the socket, the lower end portion of the anchor rod being screwed into the nut.

According to one embodiment, the invention also provides a waterproof and thermally insulating tank for storing a fluid, the waterproof and thermally insulating tank comprising a load-bearing wall, anchoring devices fixed to the load-bearing wall and a tank wall anchored to the supporting wall using said anchoring devices, the tank wall successively presenting in a thickness direction, from the outside towards the inside of the tank, a thermally insulating barrier and a sealing membrane which rests against the thermally insulating barrier, in which the thermally insulating barrier comprises thermally insulating blocks of parallelepiped shape which are juxtaposed on the supporting wall, said thermally insulating block comprising a cover plate defining a support surface for the membrane waterproofing;
in which at least one said anchoring device is as mentioned above, the lower end portion of the anchoring rod being fixed to the supporting wall between a plurality of thermally insulating blocks, the lower plate of the anchoring device cooperating with the plurality of thermally insulating blocks in order to tighten the plurality of thermally insulating blocks towards the load-bearing wall.

According to embodiments, such a waterproof and thermally insulating tank may include one or more of the following characteristics.

Thermally insulating blocks can be made in various ways. According to one embodiment of the tank, a said thermally insulating block comprises a bottom plate parallel to and spaced from the cover plate, a block of fiber-reinforced polymer foam arranged between the cover plate and the bottom plate and in which the lower plate of the anchoring device cooperates directly or indirectly with said bottom plate without exerting tightening on the block of polymer foam.

According to one embodiment, the tank further comprises a primary thermally insulating barrier resting against the sealing membrane and a primary sealing membrane resting against the primary thermally insulating barrier, the primary sealing membrane being intended to be in contact with the fluid.

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

Such a tank can be part of a land storage installation, a storage installation placed on a seabed, for example to store LNG or be installed in a floating, coastal or deep water structure, in particular an LNG ship, a floating storage and regasification unit (FSRU), a floating production and offshore storage unit (FPSO) and others.

According to one embodiment, a vessel for transporting a fluid comprises a double hull and a aforementioned waterproof and thermally insulating tank placed in the double hull. According to one embodiment, the double shell comprises an internal shell forming the supporting wall of the waterproof and thermally insulating 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 sealed and thermally insulating tank of the vessel to a floating or terrestrial storage installation and a pump for driving fluid through the insulated pipelines from or to the floating or land-based storage facility to or from the sealed and thermally insulating vessel of the vessel.

According to one embodiment, the invention also provides a method of loading or unloading such a vessel, in which a fluid is conveyed through insulated pipes from or to a floating or terrestrial storage installation to or from the sealed tank and thermally insulating of the aforementioned vessel.

According to one embodiment, the invention also provides a mounting method for mounting a aforementioned anchoring device, the method comprising the following steps:
- position an anchoring device according to one of claims 1 to 7 to the right of a socket fixed on a supporting wall between a plurality of thermally insulating blocks of parallelepiped shape which are juxtaposed on the supporting wall, the socket containing a nut housed in the socket so as to be blocked from rotating in the socket,
- screw the lower end portion of the anchor rod into the nut by inserting the first fixing tool into the first recess of the upper end of the anchor rod, the first fixing tool passing through the first orifice of the upper plate,
- engage the lower plate with at least one said thermally insulating block by screwing the nut towards the lower end of the anchor rod by inserting the second fixing tool into the second recess of the nut, the second fixing tool passing through the first orifice of the upper plate.

Thanks to these characteristics, it is possible to reduce the number of steps necessary to carry out in situ during the manufacture of a waterproof and thermally insulating tank.

According to one embodiment, the method further comprises:
- mount a primary coupler on the anchoring device by screwing a stud into the first through hole of the upper plate.

According to one embodiment, the method comprises:
- weld the anti-rotation plate to the contour of the screwed nut in order to block the rotation of the nut, the welding being carried out by inserting a welding tool through the upper plate.

According to one embodiment, the method comprises a step of measuring the position of the nut, the method comprising:
insert a first measuring instrument into a first measuring orifice formed in the upper plate, opposite the nut and measure the distance d1 between the nut and the upper plate,
insert a second measuring instrument into a second measuring orifice formed in the upper plate, facing the lower plate, then measure the distance d2 between the upper plate and the lower plate, then
compare the distance d1 with the distance d2 in order to determine the position of the nut in relation to the lower plate.

Thanks to these characteristics, it is possible to know the position of the nut and therefore to determine whether the tightening of the nut corresponds to the desired parameters.

Brief description of the 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 attached drawings.

There represents a cutaway perspective view of a tank wall.

There is a side sectional view of the tank wall according to arrow II of the , showing the anchoring device according to one embodiment.

There is a zoomed, side view, in transparency, of an embodiment similar to the .

There is a partial perspective view of the anchor rod of the embodiments presented in Figures 2 and 3.

There is a perspective view of the nut shown in Figures 2 and 3.

There is a perspective view of the anti-rotation plate shown in Figures 2 and 3.

There is a top view of the anchoring device shown in Figures 2 and 3.

There is an analogous view of the in which the anti-rotation plate has been omitted, showing another embodiment of the anchoring device.

There is a cut-away schematic representation of an LNG ship tank and a loading/unloading terminal for this tank.

On the , we have shown the multilayer structure of a tank wall 1, waterproof and thermally insulating for the storage of a fluid, such as liquefied natural gas (LNG). The tank wall 1 successively comprises, in the direction of thickness, from the outside of the tank towards the inside of the tank, a secondary thermally insulating barrier 3 retained on a supporting wall 2, a secondary waterproof membrane 4 resting against the secondary thermally insulating barrier 3, 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 fluid contained in the tank.

The supporting wall 2 can in particular be formed by the hull or 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 supporting wall 2 by means of anchoring devices 20 which will be described in detail later. The secondary insulating blocks 7 have a general parallelepiped 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 onto 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 expansion coefficient 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 which have a generally parallelepiped shape and dimensions of length and width identical to those of the secondary insulating blocks 7. Each of the primary insulating blocks 11 is positioned to the right of the one of the secondary insulating blocks 7, in alignment thereof in the direction of thickness of the tank wall 1.

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

On the , a secondary insulating block 7 has been omitted to reveal shims of thickness 12 and beads of putty 13 intended to compensate for flatness defects in the supporting wall 2. A shim of thickness 12 is notably shown on the . Positioning wedges 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 a primary insulating block 11 is anchored to the supporting 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 the , we observe more precisely the structure of a secondary insulating block 7 and an anchoring device 20 according to one embodiment.

The first and second secondary insulating blocks 7 each comprise a layer of insulating polymer foam 16 sandwiched between a bottom plate 14 and a cover plate 15. The base plate 14 and the cover plate 15 are for example made of wood plywood.

The layer of insulating polymer foam 16 is glued to the bottom plate 14 and the cover plate 15. The insulating polymer foam can in particular be a polyurethane-based foam, optionally reinforced by fibers.

In order to position an anchoring device 20 between the four corners of four adjacent secondary insulating blocks 7 (only two of which are visible in the sectional view of the ), the bottom plate 14 of each secondary insulating block 7 has a cutout at its corner zone to release a clearance in the form of a rectangular chimney 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 in the form of a rectangular chimney.

The corner portion is intended to directly or indirectly receive the support of the anchoring device 20, for example on the the anchoring device 20 is supported by means of a spacer piece 50 bearing on the bottom plate 14 of the secondary insulating block 7.

According to a variant not shown, the first and second insulating blocks have a box shape comprising a bottom panel parallel to a cover panel spaced therefrom and side sails arranged between the bottom panel and the cover panel to delimit an interior space filled with an insulating pad such as perlite, glass wool or rock wool.

Such insulating boxes also have corner portions and spacer pieces in the form of battens which can receive the anchoring device 20. Such insulating boxes are described in particular in document FR2973097A1.

With reference to Figures 2 to 7, we now describe the structure of an anchoring device 20 according to one embodiment.

The anchoring device 20 comprises a clamping assembly 30 and an anchoring rod 22.

The lower end 61 of the anchor rod 22 is received in a socket 23 whose base is welded to the supporting wall 2 in a central position of the clearance between the corner zones of four adjacent secondary insulating blocks 7. The socket 23 forms a ball joint for the anchor rod 22. The socket 23 houses a nut 18 which is blocked in rotation by the socket 23 into which the lower end 61 of the anchor rod 22 is screwed. nut 18 is for example a self-locking nut. The anchor rod 22 extends in the thickness direction of the tank wall 1 and passes between the adjacent secondary insulating blocks 7.

The clamping assembly 30 successively comprises, in the wall thickness direction, a lower plate 31, a spacer member 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 supporting wall 2.

The contour of the clamping assembly 30 is for example rectangular and of the same dimension. Alternatively, the contour shape of the clamping assembly 30 could be different, for example hexagonal or circular.

The lower plate 31 is held by the anchoring rod 22 in the direction of the supporting wall 2, resting on the spacer piece 50 which is arranged between the lower plate 31 and the bottom plate 14, thus transmitting a tightening force of the clamping assembly 30 towards the supporting wall 2.

The upper end portion of the anchor rod 22 is engaged through a central bore 41 of the lower plate 31. The upper end portion is in a housing 45 formed by a space between the lower plate 31, the plate upper 32 and a spacer member 33.

A nut 42 cooperates with a thread provided at the upper end portion of the anchor rod 22 so as to retain the lower plate 31 in the direction of the supporting wall 2.

In the embodiment shown, the anchoring device 20 comprises one or more spring elements 43, of the Belleville washer type. The spring elements 43 are threaded onto the anchor rod 22 between an upper end 52 of the nut 42 and the lower plate 31, which ensures elastic anchoring of the secondary insulating blocks 7 on the supporting wall 2.

The upper end portion of the anchor rod 22 comprises an upper end 44 comprising a recess 60 intended to serve as a gripping area for a first screwdriving tool such as a screwdriver in order to rotate the anchor rod 22 relative to the clamping assembly for screwing the portion 61 of the anchor rod 22 into the nut 18. Such an upper end portion of the anchor rod 22 is particularly visible on the .

The nut 42 has a nut head with a through passage 64 located between the upper plate 32 and the upper end 44 of the anchor rod 22 in alignment with and of the recess 60 in order to allow the passage of the first screwdriving tool up to recess 60.

The head of the nut 42 has an indentation 62 serving as a gripping area for a second screwdriving tool intended to rotate the nut 42 relative to the tightening assembly 30.

In order to allow the passage of the first and second screwing tools, the upper plate has a through hole 47 located in its center and opposite the recess 60 of the anchor rod 22 and the recess 62 of the nut 42. The nut 42 comprises a circular projection 51 at the upper end 52 of the nut 42. An anti-rotation plate 63 having a central orifice 53 which surrounds the circular projection 51 of the nut is welded locally to the upper end 52 of the nut 42, at the level of said circular projection 51 so as to prevent unscrewing of the nut 42.

The nut 42 has a lower portion engaged in the bore 41 of the lower plate.

The spacer member 33 further comprises two bores which pass through it in the direction of thickness of the tank wall and in which are engaged two fixing screws 34 which connect the lower plate 31 and the upper plate 32 to two faces opposite the spacer member 33. More precisely, the lower end 35 of each fixing screw 34 is threaded and screwed into a tapped hole 38 of the lower plate 31.

At the opposite end, each fixing screw 34 comprises a head 36, for example conical or flat, housed in a sliding manner 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 Figures 2 and 3, 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 manufacturing, by adjusting the length engaged by screwing into the tapped holes 38.

The spacer member comprises a stop piece having a lower face and an upper face parallel to the plates 32 and 31. The thickness of the spacer block 33 between the lower face and the upper face defines a minimum spacing between the plate lower plate 31 and the upper plate 32. This minimum spacing is reached in an abutment position, shown for example in Figures 2 and 3, in which the lower plate 31 and the upper plate 32 abut against the lower face and the face upper 48 of the spacer block 33.

The spacer member 33 comprises for example a first rigid part spaced and parallel to a second rigid part. According to a variant, the spacer member 33 comprises a stop piece having the shape of a bridge, a portion of which passes between the anti-rotation plate 63 and the upper plate 32. In this variant, said portion has a through passage 65 in order to allow the passage of the first and second screwing tools up to respectively the recess 60 of the anchor rod 22 and the recess 62 of the nut 42.

In order to measure whether the adjustment of the nut 42, in particular the tightening of the nut 42, is suitable with the desired parameters, the upper plate 32 can present, as is illustrated in the , a first measuring orifice 58 and a second measuring orifice 59.

The first measuring orifice 58 is located near the through orifice 47 and opens opposite the nut 42 or opposite the anti-rotation plate 63. The second measuring orifice 59 is located at a greater distance from the through orifice 47 than the first measuring orifice 58 and opens opposite the lower plate 31.

To carry out the measurement, a measuring instrument, for example a rod, is inserted into the first measuring orifice 58 in order to determine the distance between the upper end 52 of the nut 42 and the upper plate 32 then, the instrument measuring instrument, or another measuring instrument, is inserted into the second measuring orifice 59 in order to determine the distance between the upper plate 32 and the lower plate 31. With regard to these measurements, it is then possible to determine the position of the nut 42 relative to the lower plate 31 and therefore to reliably adjust said nut 42.

In reference to the in which the anti-rotation plate has been deliberately omitted, identical or similar elements have the same reference incremented by 100, they will not be repeated. In this variant embodiment, the spacer member 133 further comprises an elastically compressible member 166 tending to maintain the lower plate 131 and the upper plate 132 in a spaced position. The elastically compressible member 166 being located between the lower plate 131 and the upper plate 132, in the bores of the spacer member 133, around the fixing screws 134. The elastically compressible member 166, here represented in the form of a helical spring, is configured to compress elastically to said abutment position of the lower plates 131 and upper 132 against the abutment piece 33 in response to a force tending to bring the upper plate 132 closer to the lower plate 131. For further details concerning the elastically compressible member, reference can be made to document WO2021239712A1.

An assembly method will be described here for mounting a aforementioned anchoring device 20, in relation to the . The process described below is for example carried out by a technician directly during the manufacture of a waterproof and thermally insulating tank.

The assembly process includes the following steps:
- position the anchoring device 20 as explained previously in relation to the , that is to say between four corners of the secondary insulating blocks 7;
- insert the anchor rod 22 into the socket 23 then into the nut 18 located in the socket 23;
- insert a first screwing tool, through the through hole 47 of the upper plate 32, the hole 53 of the anchor plate and through the through passage 64 of the nut head 42 until reaching l imprint 60 of the anchor rod 22 as illustrated by arrow 55 on the ;
- screw the anchor rod 22 into the nut 18 which is blocked in rotation by the socket 23 then remove the first screwing tool from the cavity 60;
- insert a second screwing tool in a manner similar to the first screwing tool until reaching the indentation 62 of the nut 42 as illustrated by arrow 56;
- screw the nut 42 in order to tighten the Belleville washers according to the desired setting and in order to anchor the lower plate 31 against the spacers 50, towards the supporting wall 2 then, remove the second screwing tool from the recess 62 ;
- weld the anti-rotation plate 63 at the level of the circular projection 51, for example by the spot welding technique using a spot welding machine directly through the through hole 47 of the upper plate 32.

Thanks to these characteristics, the number of steps of the method of mounting the anchoring device 20 is less than the number of steps that must be carried out to mount another anchoring device conventionally used in the field in a tank.

Optionally, for the anchoring member illustrated on the , the aforementioned method further comprises:
- modify the tightening of the two fixing screws 34 as illustrated by arrows 57. This step is particularly advantageous in order to adjust the preload of the elastically compressible members 166.

In reference to the , a cutaway view of an LNG ship 70 shows a tank 71, watertight and thermally insulated, of generally prismatic shape mounted in the double hull 72 of the ship 70. The wall of the watertight and thermally insulating tank 71 includes a primary watertight 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 70, 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 70 can be connected, by means of appropriate connectors, to a maritime or port terminal to transfer a cargo of LNG from or to the watertight tank and thermally insulating 71.

There 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 a movable 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 connect to the loading/unloading pipes 73. The adjustable mobile arm 74 adapts to all LNG carrier templates. A connection 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 includes 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 onshore installation 77 over a long distance, for example 5 km, which makes it possible to keep the LNG ship 70 at a long 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 on-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 quite obvious that it is in no way limited 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. For example, the anchoring device is adapted to anchor a plurality of insulating blocks present in a tank comprising a structure having a single thermally insulating barrier retained on a supporting wall and a waterproof membrane intended to be in contact with the fluid contained in the tank, the waterproof membrane resting against the thermally insulating barrier.

The use of the verb “include”, “understand” or “include” and 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 parenthetical reference sign shall not be construed as a limitation of the claim.

Claims (15)

Anchoring device (20, 120) intended to retain a thermally insulating block (7) against a supporting wall (2), the anchoring device (20, 120) comprising:
a clamping assembly (30) comprising a lower plate (31, 131), an upper plate (32, 132) parallel to the lower plate (31, 131), a connecting member (34, 134) connecting the lower plate ( 31, 131) to the upper plate (32, 132) and a spacer member (33, 133) arranged between the lower plate (31, 131) and the upper plate (32, 132),
an anchor rod (22, 122) engaged in a through opening (41, 141) of the lower plate (31, 131) and projecting from the clamping assembly (30) through the through opening (41, 141) of the lower plate (31, 131), the anchor rod (22, 122) comprising a threaded lower end portion (61) intended to be fixed to the supporting wall (2) and a threaded upper end portion opposite the lower end portion (61) and located between the lower plate (31, 131) and the upper plate (32, 132),
a nut (42, 142) screwed onto the upper end portion of the anchor rod (22, 122) located between the lower plate (31, 131) and the upper plate (32, 132), the nut ( 42, 142) engaging the anchor rod (22, 122) with an upper surface of the lower plate (31, 131) so as to be able to exert a restoring force on the lower plate (31, 131) in the direction of the lower end portion (61), in which the upper end portion has an upper end (44) comprising a first recess (60) intended to serve as a gripping zone for a first screwdriving tool intended to rotate the anchor rod (22, 122) relative to the clamping assembly (30) to screw the lower end portion (61) of the anchor rod (22, 122) to the supporting wall (2) , the upper plate (32, 132) having a first through hole (47, 147) located opposite the first cavity (60) in order to form a passage for the first screwing tool. Anchoring device according to claim 1, wherein the nut (42, 142) has a nut head surmounting the upper end (44) of the anchor rod (22, 122), the nut head having a through passage (64) located between the upper plate (32, 132) and the upper end (44) of the anchor rod (22, 122) in alignment with the first through hole (47, 147) and the first cavity (60) to allow the first screwdriving tool to pass to the first cavity (60), the nut head having a second cavity (62) intended to serve as a gripping area for a second screwdriving tool intended rotating the nut (42, 142) relative to the anchor rod (22, 122), the first through hole (47, 147) being located opposite the second cavity (62) of so as to form a passage for the second screwdriving tools. Anchoring device according to claim 2, in which the second cavity (62) is formed by a peripheral wall of the through passage (64) of the nut head. Anchoring device according to one of claims 1 to 3, comprises an anti-rotation plate (63) arranged between the nut (42, 142) and the upper plate (32, 132) and intended to be fixed to the nut (42, 142) so as to block the rotation of the nut (42, 142). Anchoring device according to one of claims 1 to 4, in which at least one spring element (43, 143) surrounding the anchor rod (22, 122) is located between the nut (42, 142) and the lower plate (31, 131) preferably the at least one spring element (43, 143) comprises a stack of Belleville washers. Anchoring device according to one of claims 1 to 5 in which the spacer member (33, 133) comprises a stop piece defining a spacing between the lower plate (31, 131) and the upper plate (32, 132), the lower (131) and upper (132) plates abutting against opposite surfaces of the abutment piece. Anchoring device according to one of claims 1 to 5, in which the spacer member (133) comprises a stop piece defining a minimum spacing between the lower plate (131) and the upper plate (132) in a abutment position of the lower (131) and upper (132) plates against the abutment part, the abutment part comprising a rigid part, the spacer member (133) further comprising an elastically compressible member (166) tending to maintain the lower plate (131) and the upper plate (132) in a spaced position, the connecting member (134) defining a maximum spacing between the lower plate (131) and the upper plate (132) in the spaced position, said maximum spacing being greater than said minimum spacing, the elastically compressible member (166) being configured to compress elastically up to said abutment position of the lower (131) and upper (132) plates against the abutment piece in response to a effort tending to bring the upper plate (132) closer to the lower plate (131). Anchoring device according to one of claims 1 to 7, further comprising a socket (23) intended to be fixed to the supporting wall (2), and a nut (18) housed in the socket (23) so as to be locked in rotation in the socket (23), the lower end portion (61) of the anchor rod (22, 122) being screwed into the nut (18). Waterproof and thermally insulating tank for storing a fluid, the waterproof and thermally insulating tank comprising a load-bearing wall (2), anchoring devices fixed to the load-bearing wall and a tank wall (1) anchored to the load-bearing wall ( 2) using said anchoring devices, the tank wall (1) successively presenting in a thickness direction, from the outside towards the inside of the tank, a thermally insulating barrier (3) and a membrane sealing (4) which rests against the thermally insulating barrier (3), in which the thermally insulating barrier (3) comprises thermally insulating blocks (7) of parallelepiped shape which are juxtaposed on the supporting wall (2), a said thermally insulating block (7) comprising a cover plate (15) defining a support surface for the sealing membrane (4);
in which at least one said anchoring device (20, 120) is according to one of claims 1 to 8, the lower end portion (61) of the anchoring rod (22, 122) being fixed to the supporting wall (2) between a plurality of thermally insulating blocks (7), the lower plate (31, 131) of the anchoring device (20, 120) cooperating with the plurality of thermally insulating blocks (7) in order to tighten the plurality of thermally insulating blocks (7) towards the supporting wall (2). Waterproof and thermally insulating tank according to claim 9, in which said thermally insulating block (7) comprises a bottom plate (14) parallel to and spaced from the cover plate (15), a reinforced polymer foam block (16). of fibers arranged between the cover plate (15) and the bottom plate (14) and in which the lower plate (131) of the anchoring device (20, 120) cooperates directly or indirectly with said bottom plate (14) without exerting any tightening on the polymer foam block (16). Mounting method for mounting an anchoring device according to one of claims 1 to 7, the method comprising the following steps:
- position an anchoring device (20, 120) according to one of claims 1 to 7 to the right of a socket (23) fixed on a supporting wall (2) between a plurality of thermally insulating blocks (7) of shaped parallelepiped which are juxtaposed on the supporting wall (2), the socket (23) containing a nut (18) housed in the socket (23) so as to be blocked in rotation in the socket (23),
- screw the lower end portion (61) of the anchor rod (22, 122) into the nut (18) by inserting the first fixing tool into the first recess (60) of the upper end ( 44) of the anchor rod (22, 122), the first fixing tool passing through the first orifice (47) of the upper plate (32, 132),
- engage the lower plate (31, 131) with at least one said thermally insulating block (7) by screwing the nut (42) towards the lower end (61) of the anchor rod (22, 122) by inserting the second fixing tool into the second recess (62) of the nut (42), the second fixing tool passing through the first orifice (47) of the upper plate (32, 132). Mounting method according to claim 11, further comprising:
- mount a primary coupler on the anchoring device (20, 120) by screwing a stud into the first orifice (47) passing through the upper plate (32, 132). Vessel (70) for transporting a cold liquid product, the vessel comprising a double hull (72) and a waterproof and thermally insulating tank (71) according to one of claims 9 to 10, arranged in the double hull. Transfer system for a fluid, the system comprising a vessel (70) according to claim 13 insulated pipes (73, 79, 76, 81) arranged so as to connect the sealed and thermally insulating tank (71) of the vessel to an installation floating or land storage facility (77) and a pump for driving a fluid through the insulated pipes to or from the floating or land storage facility to or from the sealed and thermally insulating vessel of the vessel. A method of loading or unloading a ship (70), in which a fluid is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or land storage facility (77) to or from the tank (71) of the ship (70) according to claim 13.