SPACER BLOCK FOR AN ANCHORING DEVICE INTENDED TO RETAIN INSULATING BLOCKS

Abstract

The invention relates to a spacer block (33) adapted for an anchoring device (20) intended to retain insulating blocks (7, 11) against a load-bearing wall (2), the anchoring device comprising: - a clamping assembly (30) having 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 the spacer block, - an anchor rod (22) projecting from the clamping assembly perpendicularly to the lower plate, in an anchoring direction of the anchoring device, the anchor rod having a lower end intended to be attached to the load-bearing wall and an upper end opposite the lower end and coupled to the lower plate, the spacer block being intended to be arranged between the lower plate and the upper plate to define a spacing between the lower plate and the upper plate,The spacer block is made at least partially of plywood comprising a plurality of wood veneer layers arranged one against the other, parallel to a veneer plane (PP1; PP2; PP3) of the spacer block. According to the invention, the veneer plane of the spacer block is oriented to extend perpendicularly to said lower and upper plates of the clamping assembly. The invention also relates to such an anchoring device. Fig. 3,

Description

Title of the invention: SPACER BLOCK FOR AN ANCHORING DEVICE INTENDED TO RETAIN INSULATING BLOCKS technical field

[0001] The invention relates to the field of sealed and thermally insulated tanks integrated into a load-bearing structure to contain a cold fluid, in particular to membrane tanks for containing liquefied gases, and in particular to mechanical anchoring devices usable in a wall of such a tank.

[0002] In particular, the invention relates to the field of sealed and thermally insulated tanks for the storage and / or transport of liquefied gases at low temperatures, such as tanks for the transport of Liquefied Natural Gas (LNG) at approximately -162°C at atmospheric pressure, Liquid Hydrogen (LH2) at -253°C at atmospheric pressure, Ammonia (NH3) at -30°C at atmospheric pressure, or Liquefied Petroleum Gas (also called LPG) having, for example, a temperature between -50°C and 0°C. These tanks can be installed on land or on a floating structure.

[0003] In the case of a floating structure, the tank may be intended for the transport of liquefied gas or for receiving liquefied gas used as fuel for the propulsion of the floating structure. Previous technique

[0004] A sealed and thermally insulated liquefied natural gas storage tank arranged in a load-bearing structure and whose walls have a multilayer structure, namely from the outside to the inside 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 membrane 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.

[0005] Each primary and secondary thermal insulation barrier comprises a set of modular insulating blocks, respectively primary and secondary, generally parallelepiped in shape, which are juxtaposed and thus form a support surface for a respective waterproofing membrane. The insulating blocks are anchored to the load-bearing structure by means of anchoring devices that are fixed to the load-bearing structure and 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 hold them against the load-bearing structure.

[0006] The anchoring devices are installed during the assembly of the insulating blocks on the load-bearing structure, at the ship construction site. Summary of the invention

[0007] Known anchoring devices comprise a clamping assembly including a lower plate, an upper plate parallel to the lower plate, a connecting member linking the lower plate to the upper plate, and a rigid spacer block arranged between the lower and upper plates, defining a minimum spacing between the lower and upper plates in a position where the lower and upper plates are abutted against the spacer block. The spacing defined by the spacer block has a very precise measurement that is necessary to allow the construction of the tank wall.

[0008] The spacer blocks are, for example, made of plywood with a plurality of veneer layers arranged parallel to a veneer plane parallel to the lower and upper plates, which facilitates machining in directions perpendicular to the veneer plane. They are cut to a thickness that precisely corresponds to the minimum spacing distance.

[0009] However, the properties of plywood mean that the dimensions of the cut spacer block can vary depending on the environmental conditions of their implementation, in particular depending on the ambient humidity.

[0010] To ensure proper implementation, it is necessary to store the spacer blocks on site for several days, or even weeks, before use. The spacer blocks then deform according to the ambient humidity conditions, and they are all rectified before use: they are cut to ensure that their thickness, measured in a direction perpendicular to the lower and upper plates, corresponds to the specified spacing distance with the required accuracy.

[0011] For example, a ship with a 174,000 m³ tank may have approximately 12,000 anchoring devices, and therefore 12,000 spacer blocks. These storage and rectification steps are thus lengthy and costly.

[0012] To this end, the invention proposes a spacer block adapted for an anchoring device intended to retain insulating blocks against a load-bearing wall, the anchoring device comprising: - a clamping assembly comprising a lower plate, an upper plate parallel to the lower plate, and a connecting element linking the lower plate to the top plate, and the spacer block, - an anchor rod projecting from the clamping assembly perpendicularly to the lower plate, in an anchoring direction of the anchoring device, the anchor rod having a lower end intended to be attached to the load-bearing wall and an upper end opposite the lower end and coupled to the lower plate, - the spacer block being intended to be arranged between the lower plate and the upper plate, to define a spacing between the lower plate and the upper plate, the spacer block being made at least partially of plywood comprising a plurality of layers of wood veneer arranged against each other, parallel to a veneer plane of the spacer block, in which the veneer plane of the spacer block is oriented so as to extend perpendicularly to said lower and upper plates of the clamping assembly.

[0013] Thanks to these characteristics, the spacer block is less susceptible to deformations due to humidity in the direction perpendicular to the lower and upper plates along which the spacing is measured. Therefore, it is no longer necessary to store the spacer blocks on site or to rectify them before use.

[0014] According to other advantageous embodiments, such a spacer block may have one or more of the following characteristics.

[0015] According to one embodiment, the veneer layers of the plywood of the spacer block are each made of one of the following woods: birch, spruce, eucalyptus.

[0016] According to one embodiment, the plywood of the spacer block comprises a number of wood veneer layers per centimeter in a direction orthogonal to the veneer plane of between 4 and 8 layers, and preferably between 7 and 8 layers.

[0017] According to one embodiment, a contour of the spacer block in a plane orthogonal to the anchoring direction has a shape and dimensions identical to those of the contour of the lower plate in this orthogonal plane.

[0018] According to one embodiment, the spacer block is made from a single piece. It is then entirely made of plywood.

[0019] According to one embodiment, the spacer block comprises several separate parts. It is then preferably made partially of plywood.

[0020] According to one embodiment, the spacer block comprises two distinct lateral portions, each made of plywood comprising a plurality of layers of wood veneer arranged against each other, parallel to the veneer plane of the spacer block.

[0021] According to one embodiment, the spacer block comprises a central part positioned between the two lateral portions.

[0022] According to one embodiment, the central part of the spacer block is made of a material other than plywood, for example glass wool, and having a thermal conductivity of less than 0.050 W / mK

[0023] This solution advantageously allows for the use of less plywood. Furthermore, cutting the plywood is simplified. Such a central section serves only a thermal function.

[0024] According to one embodiment, the spacer block has two lower and upper faces opposite and parallel to each other, the lower face being intended to bear against the lower plate of the anchoring device and the upper face being intended to bear against the upper plate of the anchoring device, the lower and upper faces being connected by longitudinal and transverse lateral faces which are perpendicular to each other and perpendicular to both the lower and upper faces, the plating plane of the spacer block is oriented parallel to one of the longitudinal or transverse lateral faces of the spacer block.

[0025] According to one embodiment, the spacer block comprises a lower face intended to be oriented towards the lower plate, and a housing opening onto said lower face, said housing being adapted to receive an upper end of the anchor rod.

[0026] According to one embodiment, the spacer block comprises an upper face intended to be oriented towards the upper plate, a central hole being provided in this upper face and opening into the housing.

[0027] According to one embodiment, the spacer block has at least two through lateral orifices, each of these at least two lateral orifices being adapted for the passage of a connecting rod of the connecting member.

[0028] The invention also relates to an anchoring device for retaining 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 element linking the lower plate to the upper plate, and a spacer block arranged between the lower plate and the upper plate, defining a spacing between the lower plate and the upper plate, - an anchor rod projecting from the clamping assembly perpendicularly to the lower plate, in an anchoring direction of the anchoring device, the anchor rod having a lower end intended to be attached to the load-bearing wall and an upper end opposite the lower end and coupled to the lower plate, - the spacer block being made at least partially of plywood comprising a plurality of layers of wood veneer arranged against each other, parallel to a veneer plane of the spacer block, wherein the veneer plane of the spacer block extends perpendicularly to said lower and upper plates of the clamping assembly.

[0029] According to one embodiment of the anchoring device, the clamping assembly comprises at least two connecting rods arranged symmetrically with respect to a central hole in said spacer block. Thanks to these features, the forces can be distributed evenly within the clamping assembly.

[0030] According to one embodiment, the clamping assembly of the anchoring device has an overall parallelepiped shape, the lower plate and the upper plate having a rectangular contour.

[0031] According to one embodiment, the clamping assembly of the anchoring device forms a secondary clamping member intended to cooperate with a secondary insulating barrier, the upper plate having a central bore in which is screwed a stud projecting from the clamping assembly opposite the anchor rod, said stud carrying a primary clamping member intended to cooperate with a primary insulating barrier.

[0032] According to one embodiment, the anchoring device further comprises a sleeve engaged on the lower end of the anchor rod and intended to be fixed on the load-bearing wall, the sleeve having a housing receiving the lower end of the anchor rod so as to form a ball joint.

[0033] According to one embodiment, the anchor rod, the lower plate and the upper plate of the anchoring device are made of metal.

[0034] According to one embodiment, said insulating block belongs to a thermally insulating barrier and comprises a cover plate defining a support surface for a sealing membrane of this thermally insulating barrier. The insulating block also comprises a base plate parallel to and spaced from the cover plate and a polymer foam block, optionally fiber-reinforced, arranged between the cover plate and the base plate. The lower plate of the anchoring device cooperates directly or indirectly with said base plate of the insulating block without exerting any clamping force on the polymer foam block. For example, the lower plate of the anchoring device may cooperate with the base plate via a rigid element such as a spacer, a post, and / or a batten, for example, made of plywood.

[0035] According to one embodiment, said insulating block comprises a base plate, and successively an intermediate plate and a cover plate parallel to the base plate and mutually spaced, and two polymer foam blocks, optionally fiber-reinforced, arranged respectively between the cover plate and The intermediate plate is located between the intermediate plate and the base plate. The lower plate of the anchoring device cooperates directly with said intermediate plate at a corner area.

[0036] 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 tank wall further comprising a primary thermally insulating barrier 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, each of which is superimposed on one of the secondary insulating blocks, in which said stud passes watertight through the secondary sealing membrane and the primary clamping member is held in support towards 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.

[0037] According to one embodiment, the invention also provides a sealed and thermally insulated tank for storing a fluid, comprising a load-bearing wall, anchoring devices fixed to the load-bearing wall and a tank wall, the tank wall successively having in a thickness direction, from the outside to 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 parallelepiped-shaped insulating blocks which are juxtaposed on the load-bearing wall, said insulating blocks being clamped in the direction of the load-bearing wall by means of a plurality of anchoring devices, at least one of which is said anchoring device as described above, the lower end of the anchor rod being fixed to the load-bearing wall between a plurality of the insulating blocks,The lower plate of the anchoring device cooperates with the plurality of insulating blocks in order to clamp the plurality of insulating blocks towards the load-bearing wall.

[0038] According to one embodiment, the fluid is a liquefied gas, such as liquefied natural gas (LNG), liquefied petroleum gas (LPG), liquefied ethylene or liquid ammonia.

[0039] Such a tank may be part of an onshore storage facility, a storage facility placed on a seabed, for example to store LNG or be installed in a floating structure, coastal or deep water, including an LNG carrier, a floating storage and regasification unit (FSRU), a floating production and remote storage unit (FPSO) and others.

[0040] In one embodiment, a vessel for transporting a fluid comprises a double hull and the aforementioned tank disposed within the double hull. In another embodiment, the double hull comprises an inner hull forming the load-bearing wall of the tank.

[0041] According to one embodiment, the invention also provides a transfer system for a fluid, the system comprising the aforementioned vessel, insulated pipes arranged to connect the tank installed in the hull of the vessel to a floating or land-based storage facility and a pump to drive a fluid through the insulated pipes from or to the floating or land-based storage facility to or from the vessel's tank.

[0042] According to one embodiment, the invention also provides a method for assembling the anchoring device as described above, according to which the anchoring device is assembled without rectifying the dimensions of the spacer block after storage under the hygrometric conditions of implementation of the anchoring device.

[0043] According to one embodiment, the invention also provides a method for loading or unloading such a vessel, in which a fluid is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the vessel's tank. Brief description of the figures

[0044] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from 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.

[0045] Fig. 1 is a cutaway perspective view of a tank wall.

[0046] [Fig.2] is a side view of the tank wall along arrow II of [Fig.1].

[0047] Figure 3 is a partial cross-sectional view of one embodiment of the device anchoring used in the tank wall of [Fig.2].

[0048] Fig. 4 is a perspective view of a first example of an embodiment of the spacer block of the anchoring device of Fig. 3.

[0049] Fig. 5 is a perspective view of a second embodiment of the spacer block of the anchoring device of Fig. 3.

[0050] Figure 6 is a partial perspective view of another embodiment of the anchoring device equipped with a third embodiment of the spacer block,

[0051] Fig. 7 is a schematic top view of the tank wall of Fig. 2, showing the position of the anchoring device.

[0052] Fig. 8 is a schematic cutaway representation of a tank of a methane tanker and a loading / unloading terminal for this tank. Description of the implementation methods

[0053] By convention, the terms "lower" and "upper" are used to define the relative position of one element with respect to another, respectively in the direction of the outside or the inside of the tank as in the horizontal wall shown in [Fig. 1]. However, the following description is applicable to any wall regardless of its orientation in the Earth's gravitational field.

[0054] Figure 1 shows the multilayer structure of a tank wall 1, which is sealed and thermally insulating for the storage of a liquefied fluid, such as liquefied natural gas (LNG). The tank wall 1 comprises, successively in the thickness direction, from the outside to the inside of the tank, a secondary thermally insulating barrier 3 retained to a load-bearing wall 2, a secondary sealing membrane 4 resting against the secondary thermally insulating barrier 3, a primary thermally insulating barrier 5 resting against the secondary sealing membrane 4, and a primary sealing membrane 6 intended to be in contact with the liquefied natural gas contained in the tank (Figures 1 and 2).

[0055] The load-bearing wall 2 may, in particular, be formed by the hull or double hull of a ship. The load-bearing wall 2 is typically part of a load-bearing structure comprising a plurality of walls defining the general shape of the tank, usually a polyhedral shape.

[0056] 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 parallelepiped shape and are arranged in parallel rows.

[0057] The secondary sealing membrane 4 comprises a continuous sheet of metal struts 8 with raised edges. The metal struts 8 are welded by their raised edges to parallel weld supports which are fixed in grooves 9 formed in the cover plates of the secondary insulating blocks 7 ([Fig. 1]). The metal struts 8 are, for example, made of Invar®: that is to say, an iron and nickel alloy whose coefficient of thermal expansion is typically between 1.2 x 10⁶ and 2 x 10⁶ K⁻¹.

[0058] The primary thermally insulating barrier 5 comprises a plurality of primary insulating blocks 11 having a general parallelepiped 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 of the secondary insulating blocks 7, in alignment with it along a thickness direction D of the tank wall 1 (figures 1 and 2).

[0059] The primary sealing membrane 6 can be made in different ways. Here, it comprises a continuous sheet of metal struts 8 with raised edges. As in the secondary sealing membrane 4, the metal struts 8 are welded by their raised edges to parallel weld supports which are fixed in grooves formed on the cover plates of the primary insulating blocks 11.

[0060] In [Fig. 1], a secondary insulating block 7 has been omitted to show shims of thickness 12 and beads of sealant 13 intended to compensate for defects in the flatness of the load-bearing wall 2. Positioning shims not shown may also be provided as described in publication WO-A-2018069585.

[0061] 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 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.

[0062] In relation to [Fig. 2], the structure of an insulating block is observed more precisely. secondary 7 and a primary insulating block 11 of a wall of an embodiment of a tank according to the invention. Each secondary insulating block 7 comprises a layer of insulating polymer foam 16A sandwiched between a base plate 14A and a lid plate 15A. The base plate 14A and the lid plate 15A are, for example, made of plywood. The layer of insulating polymer foam 16A is bonded to the base plate 14A and the lid plate 15A. The insulating polymer foam may, in particular, be a polyurethane-based foam, optionally reinforced with fibers.

[0063] Figure 7 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 top view. The anchoring device 20 is represented by the outline of the clamping assembly 30. The base plate 14A of each secondary insulating block 7 has a cutout 52 at its corner area to provide a rectangular chimney-shaped recess 55 which receives the anchoring device 20.

[0064] The cover plate 15A and the insulating polymer foam layer 16A of the secondary insulating block 7 have a rectangular chimney-shaped recess 53 that exposes a corner portion 54 of the base plate 14A ([Fig. 7]). 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 later, or a rigid element integral with the base plate 14A, such as a corner post.

[0065] With reference to Figures 2 to 6, the structure of a device is now described anchoring 20 and a spacer block 33 according to the invention.

[0066] The anchoring device 20 essentially comprises a clamping assembly 30 and an anchor rod 22. The anchor rod 22 has a lower end intended to be attached to the load-bearing wall 2 and an upper end opposite the lower end and coupled to the lower plate 31 so as to be able to exert a pull on the lower plate in the direction of the lower end of the anchor rod 22.

[0067] The lower end of the anchor rod 22 is received in a socket 23, the base of which is welded to the load-bearing wall 2 in a central position within the clearance 55 between the corner areas of four adjacent secondary insulating blocks 7. The socket 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 along a longitudinal axis X parallel to the thickness direction D of the tank wall 1 and passes between the adjacent secondary insulating blocks 7. This longitudinal axis X defines the anchoring direction of the anchoring device.

[0068] The clamping assembly 30 comprises successively, in the thickness direction D of the tank wall and from the outside to the inside of the tank, a lower plate 31, the spacer block 33 and an upper plate 32 (figures 3 and 6).

[0069] The lower plate 31 and the upper plate 32 each have a general rectangular parallelepiped shape comprising two main opposite faces which are parallel to the load-bearing wall 2, perpendicular to the longitudinal axis X of the anchor rod 22, i.e. to the anchoring direction.

[0070] They are made of metal.

[0071] A contour of the spacer block 33 in a plane orthogonal to the anchoring direction has the same shape and dimensions as the contour of the lower plate 32 in this orthogonal plane. The contour of the spacer block 33 is thus also rectangular and of the same dimensions as the lower plate 32.

[0072] Alternatively, the contour shape of the clamping assembly 30 could be different, for example hexagonal or circular.

[0073] The spacer block 33 thus has a shape inscribed in a rectangular prism. Alternatively, it could have a shape inscribed in a cylinder or in a right hexagonal prism.

[0074] The spacer block 33 has a parallel lower face 48A and upper face 48B. These upper 48B and lower 48A faces are connected by parallel lateral faces 49A and 49B. When the spacer block 33 is in place in the anchoring device 20, the lower 48A and upper 48B faces are adjacent to the lower 31 and upper 32 plates.

[0075] The clamping assembly 30 further includes a connecting element linking the lower plate 31 to the upper plate 32.

[0076] This connecting element here comprises two connecting rods in the form of two fixing screws 34 which each pass through the lower plates 31 and upper plates 32 and the spacer block 33.

[0077] For this purpose, the lower plate 31 has two tapped holes 46B extending along the anchoring direction and the upper plate 32 has two through openings 46A arranged opposite the tapped holes 46B of the lower plate 31.

[0078] The spacer block 33 further comprises two through lateral openings, for example two bores 46, which pass through it in a drilling direction DP perpendicular to the lower face 48A and upper face 48B, and therefore to the lower and upper plates 31, 32 when the spacer block 33 is in place in the anchoring device 20. This drilling direction DP is parallel to the longitudinal axis X of the anchor rod 22 and to the thickness direction D of the tank wall when the anchoring device 20 is in place in the tank wall. The two bores 46 are arranged in correspondence with the tapped holes 46B of the lower plate 31 and the through openings 46A of the upper plate 31 when the spacer block 33 is in place in the anchoring device 20.

[0079] In the anchoring device 20, the two fixing screws 34 are engaged through the through openings 46A of the upper plate 31, the bores 46 of the spacer block 33 and the tapped holes 46B of the lower plate 31.

[0080] They link the lower plate 31 and the upper plate 32 to the spacer block 33.

[0081] The lower end 35 of each fixing screw 34 is threaded and screwed into the tapped hole 46B of the lower plate 31.

[0082] At the opposite end, each fixing screw has a head 36, for example cylindrical, which slides into the through opening 46A of the upper plate 32. Each through opening 46A has a shoulder against which the head 36 of the fixing screw 34 bears at the end of its tightening stroke to clamp the upper plate 32 and the lower plate 31 against the spacer block 33. The upper plate 32 and the lower plate 31 are then in their abutment position against the spacer block 33. In this position, the upper plate 32 bears against the upper face 48B of the spacer block 33 and the lower plate 33 bears against the lower face 48A of the spacer block 33.

[0083] The thickness of the spacer block 33, i.e., the distance between its lower face 48A and its upper face 48B, defines a minimum spacing between the lower plate 31 and the upper plate 32. This minimum spacing is achieved in the abutment position of the lower plates 31 and upper plates 32, shown in Figures 2 and 3, in which the lower plate 31 and the upper plate 32 are abutted respectively against the lower face 48A and the upper face 48B of the block spacing 33.

[0084] In this stop position, the inner face of the upper plate 32, oriented towards the secondary sealing membrane 4, must be precisely in line with the inner face of the cover plate 15A of each secondary insulating block 7 held by the anchoring device 20 in order to provide a flat bearing surface for receiving the secondary sealing membrane 4.

[0085] The spacing between the lower plate 31 and the upper plate 32 may be greater than the minimum spacing when the fixing screws 34 are not screwed to their screwing end position.

[0086] The spacer block 33 is made at least partially of plywood. Plywood is a material comprising a plurality of parallel veneer layers arranged against each other, each layer being made of wood. In the spacer block 33 of the anchoring device 20, the veneer layers of the plywood are oriented parallel to a veneer plane PP1, PP2 of the spacer block 33.

[0087] Remarkably, here, the plating plane PP1; PP2; PP3 of the spacer block 33 is oriented so as to extend perpendicularly to said lower plates 31 and upper plates 32 of the clamping assembly, parallel to the anchoring direction of the anchoring device 20 when the spacer block 33 is in place in the anchoring device 20.

[0088] Figures 3 to 6 show schematically three examples of embodiments of the anchoring device spacer block according to the invention.

[0089] In figures 3 to 6, identical or corresponding elements are identified by the same references.

[0090] In the three embodiments shown in Figures 3 to 6, the spacer block has a shape inscribed within a rectangular parallelepiped of the same dimensions. Its thickness E, measured along the anchoring direction of the anchoring device 20, is 52 millimeters (mm), its width W is 55 mm, and its length is 120 mm. Note that these dimensions are given for guidance only. The spacer block may have other dimensions without departing from the scope of the invention.

[0091] In the example mentioned, the precision on the thickness E of the spacer block 33 is between 0.5 and 0.8 mm in order to allow the reception of the secondary sealing membrane 4.

[0092] Preferably, the veneer layers of the plywood in which the spacer block is formed are each made of one of the following woods: birch, spruce, eucalyptus.

[0093] This plywood preferably comprises a number of layers per centimeter measured along a direction perpendicular to the veneer layers, between 4 and 8 layers per centimeter, preferably between 7 and 8 layers per centimeter.

[0094] In the first and second embodiments of the spacer block 33 shown in Figures 4 and 5, the spacer block 33 is made from a single piece.

[0095] The plating plane PP1, PP2 of the spacer block 33 is then preferably oriented parallel to one of the lateral faces 49A, 49B of the spacer block 33.

[0096] In the example of [Fig.4], the plating plane PP1 of the spacer block 33 is oriented parallel to the transverse lateral faces 49B extending across the width of the spacer block 33.

[0097] The spacer block 33 of the example in [Fig. 4] is then, for example, made by cutting a 120-millimeter-thick sheet of plywood such that the length L of the spacer block 33 extends through the thickness of the plywood sheet. The plywood sheet extends in a midplane parallel to the veneer layers. The thickness of the plywood sheet is therefore measured in a direction perpendicular to the veneer layers.

[0098] In the example of [Fig.5], the PP2 plating plane of the spacer block 33 is oriented parallel to the longitudinal lateral faces 49A extending along the length of the spacer block 33.

[0099] The spacer block 33 of the example in [Fig.5] is then, for example, made by cutting a 55 millimeter thick plywood plate, so that the width W of the spacer block 33 extends into the thickness of the plywood plate.

[0100] Regardless of the embodiment, the spacer block 33 includes a recess 45 opening onto its lower face 48A and which receives an upper end 44 of the anchor rod 22, as described below. This recess 45 here comprises a parallelepiped-shaped portion, open onto the longitudinal lateral faces 49A of the spacer block 33 and onto its lower face 48A.

[0101] Furthermore, the spacer block 33 has a central bore 45A forming a cylindrical portion of the housing 45 which opens onto the upper face 48B of the spacer block. This central bore 45A is centered on the longitudinal axis X of the anchor rod 22 and adapted to receive the upper end 44 of the anchor rod 22.

[0102] In the first and second examples of the spacer block, the recess 45 is made by machining the plywood plate. The machined recess has, for example, a length of 55 mm and extends over the entire width of the block, i.e., 55 mm.

[0103] In the third embodiment shown in [Fig.6], the spacer block 33 comprises several separate parts.

[0104] More specifically, it comprises two separate lateral portions 33A, each made of plywood, such that the PP3 veneer plane of the spacer block 33 extends perpendicularly to the lower and upper plates of the clamping assembly 20 and parallel to the transverse lateral faces 49B of the spacer block, which extend across its width W. Each lateral portion 33A is parallelepiped-shaped and forms one of the transverse lateral faces 49B of the spacer block 33. Each lateral portion 33A further includes one of the two bores 46 of the spacer block 33.

[0105] It further comprises a central part 33B arranged between the two lateral portions 33A.

[0106] The central portion 33B may contain no material, as shown in [Fig. 6]. The housing 45 and the central hole 45A of the spacer block are then formed by the space between the two lateral portions 33A. This configuration simplifies the construction of the spacer block and allows for savings in plywood.

[0107] Alternatively, the central part 33B can be an element providing a thermal function, for example glass wool. This configuration simplifies the anchoring device.

[0108] In this variant, the central portion 33B of the spacer block 33 includes the central bore 45A described previously. Preferably, the central portion 33B leaves a portion of the space between the two lateral portions 33A of the spacer block 33 free in order to accommodate the housing 45.

[0109] The lateral portions 33A and the central part 33B are arranged to provide between them the housing 45. The thickness El of the central part 33B is for example equal to 30 mm.

[0110] For this purpose, the lateral portions 33A of the spacer block 33 are, for example, cut from plywood sheets of standard thickness equal to 30 mm. The dimension L1 of each lateral portion 33A along the length of the spacer block 33 is then equal to 30 mm ([Fig.6]).

[0111] Alternatively, the lateral portions 33A of the spacer block 33 can be cut from standard-thickness plywood sheets of 35 mm and then machined to obtain a dimension L1 of 32.5 mm. This method produces a spacer block having dimensions identical to those of the spacer block conforming to one of the first and second examples described above.

[0112] Each lateral portion 33A has one of the bores 46 which accommodates one of the two fixing screws 34.

[0113] Regardless of the embodiment of the spacer block, the lower plate 31 further includes a central bore 41 which allows the passage of the upper end 44 of the anchor rod 22.

[0114] The housing unit 45 provided in the spacing block 33 is arranged opposite the central bore 41 of the lower plate 31.

[0115] The upper end 44 of the anchor rod 22 is engaged through the central bore 41 of the lower plate 31 and received in the recess 45 provided in the spacer block 33 (Figures 3 to 6). A nut 42 cooperates with a thread provided at the upper end 44 of the anchor rod 22 so as to retain the lower plate 31 towards the load-bearing wall 2 ([Fig. 3]) by bearing against an inner face of the lower plate 31.

[0116] The lower plate 31 is held by the anchor rod 22 bearing against the corner portion 54 of each of the four adjacent secondary insulating blocks 7, in the direction of the load-bearing wall 2. Here, the spacer piece 50 is positioned 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 base plate 14A.

[0117] In the embodiment shown, the anchoring device 20 further comprises one or more Belleville-type spring washers 43 ([Fig. 3]). The spring washers 43 are threaded onto the anchor rod 22 between the nut 42 and the lower plate 31, thereby ensuring elastic anchoring of the secondary insulating blocks 7 to the load-bearing wall 2. Advantageously, a locking member is also welded locally to the upper end of the anchor rod 22 to prevent the nut 42 from loosening.

[0118] The tank wall 1 could be limited to the secondary insulating barrier 3 and the secondary sealing membrane 4 to create a single-membrane tank. If the primary insulating barrier 5 and the primary sealing membrane 6 are present, the anchoring device 20 also includes a primary stage. For this purpose, the upper plate 32 has a threaded bore 47 in its center, in which is mounted a threaded base for a stud 27 intended for anchoring the primary insulating blocks 11. The stud 27 passes through a hole formed through a metal strut 8 of the secondary sealing membrane 4. The stud 27 has a collar that is welded around its periphery, around the hole, to ensure the watertightness of the secondary sealing membrane 4.

[0119] The primary stage of the anchoring device 20 also includes a primary support plate 28 which is supported in the direction of the load-bearing wall 2 on a support area 60 provided in each of the four adjacent primary insulating blocks 11 so as to retain them against the secondary sealing membrane 4. Each support area 60 is formed, for example, by a support block 60. Alternatively, it can be formed by an overhanging part of the base plate of the primary insulating block.

[0120] The gap between the insulating polymer foam layers 16B of two primary insulating blocks is filled by a thermally insulating material 61 ([Fig.2]), for example glass wool, wadding, expanded polystyrene or poly- urethane.

[0121] A nut 29 cooperates with a thread provided at the upper end of the stud 27 so as to secure the primary support plate 28 to the stud 2 ([Fig. 3]). In the embodiment shown, the anchoring device 20 further includes a Belleville-type spring washer threaded onto the stud 27 between the nut 29 and the primary support plate 28, which provides elastic anchoring of the primary insulating blocks 11 to the secondary waterproofing membrane 4.

[0122] The spacer 50 of the anchoring device 20 has a central through-hole 51 for the passage of the anchor rod 22, an upper end surface 56 for the support of the lower plate 31, and a lower end surface 57 for bearing on the secondary insulating block 7. The spacer 50 is, for example, made of plywood to limit thermal bridging. The spacer 50 preferably has the same rectangular cross-section as the lower plate 3. It may be formed from a small number of elongated pieces with simple shapes, assembled together, for example, by stapling, screwing, and / or gluing.

[0123] 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.

[0124] When the tank is empty and at room temperature, i.e. under the conditions of its initial construction, the position of the upper plate 32 is adjusted to be aligned with the cover plate 15A, so as to provide a uniform support surface for the secondary sealing membrane 4.

[0125] Remarkably, thanks to the anchoring device according to the invention, it is possible to assemble the anchoring device, and to construct the tank wall using it, directly without rectifying the dimensions of the spacer block 33 after storage under the hygrometric conditions of implementation of the anchoring device 20.

[0126] Thanks to these characteristics, the spacer block 33 is less susceptible to deformations due to humidity in the direction perpendicular to the lower and upper plates along which the minimum spacing is measured. Therefore, it is no longer necessary to store the spacer blocks 33 on site or to rectify them before use.

[0127] The spacer block 33 is initially cut to the desired dimension for its thickness in the anchoring direction, here 52 mm, with the desired precision, here for example between 0.5 and 0.8 mm. The spacer block 33 is used directly for installing the tank wall, without prior storage to adapt to hygrometric conditions or adjustment of its thickness.

[0128] The structure of the secondary insulating block 7 is described above by way of example. Also, in another embodiment of the tank, the secondary insulating blocks may have a different general structure, for example that described in document WO-A-2012127141. The secondary insulating blocks are then made in the form of a box comprising a base plate, a lid plate and load-bearing walls extending, in the thickness direction of the tank wall, between the base plate and the lid plate and delimiting a plurality of compartments filled with an insulating material, such as perlite, glass wool or rock wool.

[0129] In another embodiment of the tank, the secondary insulating blocks may have a different general structure, for example, that described in document WO-A-2014096600. The insulating polymer foam layer is then divided into two lower and upper layers separated by an intermediate plate, for example, made of plywood, bonded to them. The length of the upper layer is shorter than the length of the lower layer and exposes a lip at two longitudinal ends of the intermediate plate. A rigid pillar extends in the thickness direction of the lower layer between the intermediate plate and the base plate of each secondary insulating block, in recesses formed at the four corners of the lower layer. The rigid pillar is partially aligned with the lip to absorb the clamping force of the anchoring device, the lower plate of which can here be applied directly to the lip.

[0130] The primary insulating block 11 can be made in different ways, for example in the form of a layer of insulating polymer foam 16B sandwiched between a base plate 14B and a cover plate 15B like the secondary insulating block 7.

[0131] The base plate 14B of each primary insulating block 11 then has grooves for receiving the raised edges of the strakes 8 of the secondary sealing membrane 4. The cover plate 15B of each primary insulating block 11 also has grooves for receiving weld supports for fixing the primary sealing membrane 6.

[0132] The structure of the primary insulating panel 11 is described above by way of example. Also, in another embodiment of the tank, the primary insulating panels 22 may have a different general structure, for example that described in document WO-A-2012127141.

[0133] The technique described above for producing a tank wall having one or two sealed membranes can also be used in different types of tanks, for example to constitute 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.

[0134] With reference to [Fig. 8], a cutaway view of a vessel 70 shows a sealed and insulated tank 71 of generally prismatic shape mounted in the double hull 72 of the vessel. The wall of the tank 71 comprises a primary sealed barrier intended to be in contact with the liquefied gas contained in the tank, a secondary sealed barrier arranged between the primary sealed barrier and the double hull 72 of the vessel, and two insulating barriers arranged respectively between the primary sealed barrier and the secondary sealed barrier and between the secondary sealed barrier and the double hull 72.

[0135] In a manner known per se, loading / unloading pipelines 73 arranged on the upper deck of the ship can be connected, by means of suitable connectors, to a marine or port terminal to transfer a cargo of liquefied gas from or to the tank 71.

[0136] Figure 8 shows an example of a marine terminal comprising a loading and unloading berth 75, a subsea pipeline 76 and an onshore facility 77. The loading and unloading berth 75 is a fixed offshore facility comprising a movable arm 74 and a tower 78 which supports the movable arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading / unloading pipelines 73. The steerable movable arm 74 adapts to all ship sizes. An unshown connecting pipeline extends inside tower 78. The loading and unloading station 75 allows the ship 70 to be loaded and unloaded from or to the onshore facility 77. This facility includes liquefied gas storage tanks 80 and connecting pipelines 81 linked by the subsea pipeline 76 to the loading or unloading station 75.The subsea pipeline 76 allows the transfer of liquefied gas between the loading or unloading station 75 and the onshore installation 77 over a long distance, for example 5 km, which allows the ship 70 to be kept a long distance from the coast during loading and unloading operations.

[0137] To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and / or pumps equipping the land installation 77 and / or pumps equipping the loading and unloading station 75 are used.

[0138] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0139] The use of the verb "comprise", "comprendre" or "include" and its conjugated forms does not exclude the presence of other elements or steps than those stated in a claim.

[0140] In claims, any reference sign in parentheses may not be in- interpreted as a limitation of the claim.

Claims

Demands

1. A spacer block (33) adapted for an anchoring device (20) intended to retain insulating blocks (7, 11) against a load-bearing wall (2), the anchoring device comprising: - a clamping assembly (30) having 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 the spacer block (33), - an anchor rod (22) projecting from the clamping assembly perpendicularly to the lower plate (31), in an anchoring direction of the anchoring device, the anchor rod having a lower end intended to be attached to the load-bearing wall (2) and an upper end opposite the lower end and coupled to the lower plate (31),the spacer block (33) being intended to be arranged between the lower plate (31) and the upper plate (32) to define a spacing between the lower plate and the upper plate, the spacer block (33) being made at least partially of plywood comprising a plurality of layers of wood veneer arranged against each other, parallel to a veneer plane (PP1; PP2; PP3) of the spacer block (33), characterized in that the veneer plane (PP1; PP2; PP3) of the spacer block (33) is oriented to extend perpendicularly to said lower (31) and upper (32) plates of the clamping assembly (30).

2. Spacer block according to claim 1, wherein the veneer layers of the plywood are each made of one of the following woods: birch, spruce and eucalyptus.

3. Spacer block according to any one of claims 1 and 2, wherein the plywood comprises a number of wood veneer layers per centimeter in a direction orthogonal to the veneer plane of between 4 and 8 layers.

4. Spacer block according to any one of claims 1 to 3, wherein a contour of the spacer block (33) in a plane orthogonal to the anchoring direction has a shape and dimensions identical to those of the contour of the lower plate (31) in this orthogonal plane.

5. Spacer block according to any one of claims 1 to 4, made from a single piece.

6. Spacer block according to any one of claims 1 to 4, comprising several separate parts.

7. Spacer block according to claim 6, comprising two separate lateral portions (33A) each made of plywood comprising a plurality of layers of wood veneer arranged against each other, parallel to the veneer plane (PP3) of the spacer block (33).

8. Spacer block according to claim 7, comprising a central part (33B) disposed between the two lateral portions (33A) each other.

9. A spacer block according to claim 8, wherein the central portion (33B) is made of a material other than plywood and having a thermal conductivity of less than 0.050 W / mK

10. A spacer block according to any one of claims 1 to 9, having two opposing and parallel lower (48A) and upper (48B) faces, the lower face (48A) being intended to bear against the lower plate (31) and the upper face (48B) being intended to bear against the upper plate (32), the lower (48A) and upper (48B) faces being connected by longitudinal (49A) and transverse (49B) lateral faces which are perpendicular to each other and perpendicular to both the lower (48A) and upper (48B) faces, the plating plane (PP1; PP2; PP3) of the spacer block (33) is oriented parallel to one of the longitudinal (49A) or transverse (49B) lateral faces of the spacer block (33).

11. A spacer block according to any one of claims 1 to 10, comprising a lower face (48A) intended to be oriented towards the lower plate (31), and a housing (45) opening onto said lower face (48A), said housing (45) being adapted to receive an upper end (44) of the anchor rod (22).

12. Spacer block according to claim 11, comprising an upper face (48B) intended to be oriented towards the upper plate (32), a central hole (45A) being provided in the upper face (48B) and opening into the housing (45).

13. A spacer block according to any one of claims 1 to 12, comprising two through lateral orifices (46), each of these two lateral orifices being adapted for the passage of a connecting rod of the connecting member.

14. Anchoring device (20) for retaining insulating blocks (7, 11) against a load-bearing wall (2), comprising: - a clamping assembly (30) having 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 spacer block (33) according to any one of claims 1 to 13, - an anchoring rod (22) projecting from the clamping assembly perpendicularly to the lower plate (31), in an anchoring direction of the anchoring device, the anchoring rod having a lower end for being attached to the load-bearing wall (2) and an upper end opposite the lower end and coupled to the lower plate (31).

15. A sealed and thermally insulated fluid storage tank, comprising a load-bearing wall, anchoring devices (20) fixed to the load-bearing wall (2) and a tank wall (1), the tank wall (1) having successively in a thickness direction (D), from the outside to the inside of the tank, a thermally insulating barrier (3) and a sealing membrane (4) which rests against the thermally insulating barrier (3), in which the thermally insulating barrier (3) comprises parallelepiped-shaped insulating blocks (7) which are juxtaposed on the load-bearing wall (2), said insulating blocks (7) being clamped in the direction of the load-bearing wall (2) by means of a plurality of anchoring devices, at least one of which said anchoring device (20) is according to claim 14, the lower end of the anchoring rod (22) being fixed to the load-bearing wall between a plurality of the insulating blocks (7),the lower plate (31) of the anchoring device cooperating with the plurality of insulating blocks (7) in order to clamp the plurality of insulating blocks towards the load-bearing wall (2).

16. Vessel (70) for the transport of a fluid, the vessel comprising a double hull (72) and a tank (71) according to claim 15, disposed in the double hull (72).

17. A fluid transfer system, the system comprising a vessel (70) according to claim 16, insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the vessel to a floating or land-based storage facility (77), and a pump for conveying a fluid through the insulated pipes to or from the floating or land-based storage facility. ship's tank.

18. Method of assembling the anchoring device according to claim 14, wherein the anchoring device (20) is assembled without rectifying the dimensions of the spacer block (33) after storage under the hygrometric conditions of implementation of the anchoring device (20).

19. A method of loading or unloading a ship (70) according to claim 16, wherein a fluid is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or land-based storage facility (77) to or from the ship's tank (71).

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