FR3004508A1 - INSULATING BLOCK FOR THE MANUFACTURE OF A WATERPROOF AND INSULATED TANK WALL - Google Patents

Abstract

An insulating block (10) having a flattened overall prismatic shape for producing a sealed and insulating tank wall, comprising: a pad (1) of polymer foam with a density greater than 100 kg / m3, the polymer foam pad having notches so as to form a plurality of corner surfaces (2) each extending between two adjacent side surfaces (3) of the block, and a plurality of corner pillars (5) attached to the polymeric foam pad in notches and extending the entire thickness of the insulating block between the upper and lower surfaces, wherein the corner pillars (5) have a coefficient of thermal expansion of between 75% and 125% of the coefficient of thermal expansion of the polymeric foam constituting the block and have a yield strength in compression greater than 1.5 MPa and preferably greater than 3 MPa, the corner pillar having in each case an internal lateral surface. upper (6) glued to the corner surface (2).

Description

TECHNICAL FIELD The invention relates to the field of sealed and thermally insulating tanks arranged in a bearing structure for containing a cold fluid, particularly to membrane tanks for containing liquefied gases.

BACKGROUND OF THE INVENTION Sealed and thermally insulating vessels arranged in the hull of a vessel for the transport of liquefied natural gas (LNG) with a high methane content are known. Such a tank is disclosed for example in FR-A-2867831. In this known tank, a primary insulating barrier and a secondary insulating barrier are formed in a modular form using juxtaposed wooden parallelepiped boxes. The crates are filled with an expanded perlite insulation or aerogels. FR-A-2978748 discloses another LNG tank arranged in the hull of a ship in which a secondary insulating barrier comprises insulating blocks arranged in a repeated pattern. The insulating block comprises a generally parallelepiped flattened block of high density polymeric foam having notches extending in the thickness direction of the insulating block at the four corners of the upper and lower surfaces so as to form a plurality of cut-off sections which extend each time between two adjacent side surfaces of the block. A corner pillar is attached to the polymeric foam pad at each cutaway and extends over the entire thickness of the insulating block between the top and bottom surfaces to take up part of the compressive force and thereby limit the creep and crushing of the foam.

Summary An idea underlying the invention is to propose insulating blocks that are suitable for producing a primary insulation barrier of a sealed and thermally insulating tank in a relatively simple manner and whose service life is long.

According to one embodiment, the invention provides an insulating block having a flattened overall prismatic shape for the manufacture of a sealed and insulating tank wall, the insulating block being intended to be arranged in a repeating pattern to form an insulating barrier of the vessel wall, the insulating block comprising: a polymer foam pavement with a density greater than 100 kg / m 3 having a polygonal upper surface, an identically polygonal lower surface parallel to the upper surface and spaced from the upper surface in a direction of the thickness of the insulating block and a plurality of side surfaces extending between the upper surface and the lower surface perpendicular to the upper and lower surfaces, the polymeric foam pad having notches extending in the thickness direction of the insulating block at a plurality of angles of the upper and lower surfaces so as to e to form a plurality of corner surfaces which each extend between two adjacent side surfaces of the block, and a plurality of corner pillars attached to the polymeric foam pad in the slots and extending over the entire the thickness of the insulating block between the upper and lower surfaces, in which the corner pillars are made of a material which has, especially in the thickness direction of the insulating block, a coefficient of thermal expansion of between 75% and 125%; % of the coefficient of thermal expansion of the polymer foam constituting the block and which has a yield strength in compression greater than 1.5 MPa and preferably greater than 3 MPa, at a temperature of 23 ° C, the corner pillar having each time an inner side surface completely covering a corner surface of the polymeric foam pad, the inner side surface of the corner pillar being fixed, for example ollée, on the corner surface. When gluing the corner pillar with the foam pad at room temperature and then using the insulating block at a much lower temperature, for example in an insulating barrier of a tank wall 30 of liquefied natural gas, and especially in the primary barrier of such a vessel, differential thermal contraction is likely to create shear stresses in the bonded interface. By choosing the thermal expansion coefficient of the corner pillar, it is possible to limit these constraints to improve the strength and longevity of the bonded assembly. Similar advantages arise when the corner pillar assembly is made in another way, for example by staples. In addition, the elastic limit in compression of the corner pillar makes it possible to limit the displacement by creep of this pillar to an acceptable level, in particular to a level below the displacement that can be absorbed elastically by anchoring members retaining the block. insulation on the supporting structure of the tank wall. According to embodiments, such an insulating block may comprise one or more of the following characteristics.

According to one embodiment, the polymer foam constituting the block is a closed-cell polyurethane foam with a density greater than or equal to 130 kg / m 3. According to one embodiment, the material of the corner pillars is a polymer foam with a density greater than or equal to 170 kg / m 3, for example 210 kg / m 3. Preferably in this case, the corner pillar is a solid solid structure. According to one embodiment, the material of the corner pillars is a polymer resin. Preferably in this case, the corner pillar is a hollow structure. According to one embodiment, the material of the corner pillars is a composite which may comprise fibers embedded in a polymer resin. Preferably in this case, the corner pillar is a hollow structure. According to one embodiment, the insulating block further comprises a plywood cover panel attached to the upper surface of the polymeric foam pad, the cover panel overlapping in the corners an upper surface of the corner pillars, the cover panel cover having an outline aligned with the side surfaces of the polymer foam pad and with the lateral outer surface of the corner pillars attached to the pad. According to one embodiment, the cover panel has a plurality of countersinks disposed above each of the corner pillars. According to one embodiment, the insulating block further comprises a plywood bottom panel fixed beneath the bottom surface of the polymer foam pad, the bottom panel overlapping in the corners a bottom surface of the corner pillars, the bottom panel bottom having an outline aligned with the side surfaces of the polymer foam pad and with the lateral outer surface of the corner pillars attached to the pad. According to one embodiment, an angle pillar has in each case a constant sectional shape in a plane perpendicular to the thickness direction, the sectional shape having an outer edge set back from the intersection geometrical point. two side surfaces of the block which are adjacent to the corner surface on which the pillar is fixed. According to one embodiment, the corner surface of the block is flat and in which the sectional shape of the pillar is a trapezium comprising a large base which corresponds to the inner lateral surface of the pillar, a small base which corresponds to the outer edge located recessed from the intersection geometric point of the two side surfaces of the pavement, and two inclined side respectively located in alignment with the two side surfaces of the pavement which are adjacent to the corner surface on which the pillar is fixed. According to one embodiment, the corner surface of the block is rounded, the sectional shape of the pillar being an angular sector of a disc whose tip is cut along a straight line which corresponds to the outer edge set back from the geometric point of intersection of the two lateral surfaces of the pavement, the two radial sides delimiting the angular sector being located respectively in the alignment of the two lateral surfaces of the pavement which are adjacent to the corner surface on which the pillar is fixed. According to one embodiment, the lower surface and the upper surface of the polymer foam pad are generally rectangular, the insulating block 25 having an overall rectangular parallelepiped shape. According to one embodiment, the inner side surface comprises a gripping element projecting transversely from the corner pillar to the polymer foam pad, the catcher comprising a section in a plane parallel to the thickness of the insulation block of small area with respect to a total area of the inner side surface. Thanks to these characteristics, the anchoring surface of the corner pillar with the polymer foam block is increased, improving the technical characteristics of the assembly, the resistance to tearing.

According to one embodiment, the attachment element extends along the entire length of the corner pillar and projects over a small portion of the periphery of the corner pillar. According to one embodiment, the attachment element extends over a small portion of the length of the corner pillar. According to one embodiment, the inner side surface comprises a plurality of juxtaposed attachment elements. According to one embodiment, two successive gripping elements of the plurality are spaced on the inner side surface. According to one embodiment, at least two successive gripping elements of the plurality are adjacent. According to one embodiment, the pillar comprises a support trunk oriented according to the thickness of the insulating block and a fastening element fixed by its base on the support trunk of the corner pillar. According to one embodiment, the attachment element comprises a toothed profile. According to one embodiment, the attachment element comprises a spherical portion. According to one embodiment, the attachment element comprises a cylindrical portion. According to one embodiment, the invention also provides a sealed and thermally insulating tank arranged in a supporting structure for containing a cold fluid, in which the wall of the tank comprises successively in a thickness direction a primary waterproof membrane intended to in contact with the fluid, a primary insulating barrier, a secondary waterproofing membrane and a secondary insulating barrier disposed between the secondary waterproofing membrane and the supporting structure, wherein the primary insulating barrier comprises a set of aforementioned insulating blocks juxtaposed to form a flat support surface for the primary waterproof membrane, the upper surface of the insulating blocks being turned towards the interior of the tank, the wall of the tank further comprising anchoring members for retaining the insulating blocks on the secondary waterproof membrane, an anchoring member each comprising a support element in taken e on the upper surface of the insulating block in line with a corner pillar and a connecting element disposed between the insulating blocks juxtaposed, attached to the support element and extending from the support element in the thickness direction of the insulating blocks in the direction of the carrier structure, the connecting element being attached to the secondary insulating barrier or the carrier structure to press the insulating blocks on the secondary waterproof membrane. With these features, the corner pillar helps to recover some compression efforts to limit crushing and creep of the polymer foam in use. Such a tank may be part of an onshore storage facility, for example to store LNG or be installed in a floating structure, coastal or in deep water, including a LNG tank, a floating storage and regasification unit (FSRU ), a floating production and remote storage unit (FPSO) and others. According to one embodiment, a vessel for the transport of a cold liquid product comprises a double hull and a aforementioned tank disposed in the double hull. According to one embodiment, the invention also provides a method of loading or unloading such a vessel, in which a cold liquid product is conveyed through isolated pipes to or from a floating or land storage facility to or from the tank of the ship. According to one embodiment, the invention also provides a transfer system for a cold liquid product, the system comprising the abovementioned vessel, insulated pipes arranged to connect the vessel installed in the hull of the vessel to a storage facility. floating or terrestrial and a pump for driving a flow of cold liquid product through the insulated pipelines from or to the floating or land storage facility to or from the vessel vessel. Some aspects of the invention start from the idea of providing a relatively high safety coefficient, for example of the order of 5 to 10 or more, between, on the one hand, the compressive stress typically exerted on the angle d an insulating block in the primary insulating barrier of a membrane tank for LNG tankers and, on the other hand, the elastic limit in compression of the material constituting the corner pillars of such an insulating block. Certain aspects of the invention start from the idea of increasing the resistance of the fastener subjected to thermal variations, between the foam pad and each corner pillar. Some aspects of the invention are based on the idea of increasing the interface area between the foam pad and the inner side surface of a corner pillar. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and other objects, details, features and advantages thereof will become more clearly apparent from the following description of several particular embodiments of the invention, given only in connection with illustrative and non-limiting, with reference to the accompanying drawings. - Figure 1 is a three-quarter perspective view of an insulating block according to one embodiment. FIG. 2 is a view similar to FIG. 1 showing a block of foam of the insulating block; FIG. 3 is an enlarged perspective view of a corner pillar of the insulating block of FIG. 1. FIG. is a cross-sectional view of a corner pillar 20 according to another embodiment. - Figure 5 is a top view of an insulating block according to another embodiment. FIG. 6 is a partial three-quarter perspective view of an insulating block according to another embodiment. FIG. 7 is a cut-away perspective view of a sealed and insulating wall of a liquefied gas storage tank. FIG. 8 is an enlarged perspective view of the primary element of the wall of FIG. 7. FIG. 9 is a cutaway schematic representation of a vessel of a LNG carrier and a loading / unloading terminal of this vessel. tank. DETAILED DESCRIPTION OF EMBODIMENTS Referring to FIG. 1, an insulating block 10 has an overall flattened rectangular parallelepiped shape with cut edges 12 in the corners for passing fastening members which will be described below. The core of the insulating block 10 consists of a foam pad 1 10 shown in Figure 2. The foam pad 1 is made of high density polymer foam, for example glass fiber reinforced polyurethane foam having a density of 130 kg / m3 and a coefficient of thermal expansion equal to about 6.10-5 m / m / K. Each corner of the foam pad 1 between two adjacent side surfaces 3 is beveled at 45 ° so as to have a planar corner surface 2 interposed between the two side surfaces 3. A corner pillar 5 shown in FIG. each time fixed, for example glued, on the corner surface 2 of the foam pad 1. The corner pillar 5 has the shape of a trapezoidal prism. The surface 6 of the prism corresponding to the large base of the trapezium is the one that comes into contact with the corner surface 2. The opposite surface 7 which corresponds to the small base of the trapezium forms the cutaway 12 of the insulating block 10. The two inclined surfaces 8 are mutually perpendicular and each come in alignment with a side surface 3 of the foam pad 1. Figure 4 shows a variant of the corner pillar. The elements 25 similar or identical to those of FIG. 3 have the same reference number increased by 100. In this variant, the corner pillar 105 has the shape of a prism whose base is a quarter cylinder cut. Thus, the rear surface 106 intended to be in contact with the foam block 1 has a quarter-cylinder shape. The corner surfaces 2 of the foam block 1 must be modified in the same way in this case. Thus, the area available for bonding is greater in the case of the corner pillar 105.

Figure 9 shows a variant of the corner pillar. The elements similar or identical to those of FIG. 3 bear the same reference number increased by 400. This variant starts from the prismatic shape with trapezoidal base of the corner pillar 5. The rear surface 406 corresponds to the rear surface 6 to which protuberances 420 have been added. The protuberances 420 are intended to protrude into the foam block 401. These protuberances 420 have the shape of a tongue oriented perpendicularly to the thickness direction of the insulating block 410. These protuberances 420 extend over the entire width of the rear surface 406, an inclined surface 408 to the other.

FIG. 10 illustrates a corner pillar 405 assembled to the insulating block 410, according to section AA of FIG. 9. The corner pillar 405 has two protuberances 420 spaced apart by a connecting portion 422. This FIG. 10 specifies that the section protuberances 420 in the form of a tongue is rectangular. It also shows that the area of the base 421 of the protrusion 420 is small relative to the total area of the rear surface 406. With these protuberances 420, the corner pillar 405 has a rear surface 406 of contact with the block 1 to the assembly, the interface between the rear surface 406 of the corner pillar 405 and the corner surfaces 2 of the foam block 1 are adapted so that the surfaces The protuberances 420 are then embedded in the foam block 1. The increase of the rear surface 406 increases the contact area between the abutment 405 and the foam block 1. increases the strength of the assembly, for example in the case of a bonded assembly.

Figure 11 shows a variant of the corner pillar. The elements similar or identical to those of Figure 9 have the same reference numeral increased by 100. In this variant, the corner pillar 505 has three protuberances 520. These have a section corresponding to a circular portion. As a variant, the protuberances 520 or 420 are located, for example, on a portion of the width of the rear surface 506 or 406 of the pillar 505 or 405. FIG. 12 represents a variant of the corner pillar. Elements similar or identical to those of FIG. 9 bear the same reference number increased by 200. In this variant, the rear surface 606 of the corner pillar 605 has five protuberances 620 oriented in the direction of thickness of the insulating block 10 The protrusions 620 are adjacent stepwise to form the rear surface 606. As an alternative to the embodiments of Figures 9-12, the protuberances 420, 520 or 620 may be located, continuous or combined. Localized protuberances 420, 520 or 620 have the advantage of greatly simplifying the shaping of the rear surface 406, 506 or 606 of the abutment 405, 505 or 605, as well as that of the corner surfaces 2 of the foam block 1 The constraints are localized. The use of continuous protuberances 420, 520 or 620 makes the implementation more complex. It has the advantage of greatly increasing the rear surfaces 406, 506 or 606 of assembly and thus limit the anchoring forces in the interface. In a variant not shown, the protuberances 420, 520 or 620 are not made in one piece with the corner pillar 405, 505 or 605, but they are attached to a trunk of the pillar 405, 505 or 605 to form the rear surface 406, 506 or 606. They are then fixed for example by gluing or stapling. The corner pillar 5, 105, 405, 505 or 605 may be made of glass fiber reinforced polyurethane foam having a density of 210 kg / m 3, which has a compressive yield strength of the order of 3 MPa. at 23 ° C. This material has a coefficient of thermal expansion in the thickness of the panel 1 of the order of 60.10-6 m / mK as the foam 3. One of the advantages of using polyurethane foam is the thermal conductivity of this material. in the range of 0.030 to 0.035 W / mK at 20 ° C. An elastic limit in compression greater than 1.5 MPa at 23 ° C would be satisfactory taking into account two facts: the elastic limit in compression of the polymeric foam before damage increases when the temperature decreases (about a factor of 2 between 23 ° C and -170 ° C). The creep of the foam takes place over time and may result both from the tensioning of the restraining members at ambient temperature and the forces experienced during the entire period of use of the cold ship (between -100 and -170 ° C for the primary). As a result, the ambient resistance and the cold resistance are both relevant when it comes to selecting the insulating material. Alternatively, the corner pillar 5, 105, 405, 505 or 605 may be made of polymer resin or composite material in the form of a hollow tube, whose upper and lower ends are open or closed. The presence of a closure surface on the end has the advantage of better distributing the compression load received by the insulating block 10 in use. By way of example, it is possible to use polyetherimide (PEI) whose thermal contraction coefficient is 45 10-6 m / mK with a compressive yield stress at 23 ° C. of the order of 110 MPa. polyethylene terephthalate (PET) whose thermal contraction coefficient is 65 10-6 m / mK with a compressive yield stress at 23 ° C of the order of 80 MPa or polypropylene (PP) or polyethylene ( PE) weakly loaded with fibers to reduce the coefficient of thermal contraction in the range 45 to 75. 10-6 m / mK with a compressive yield stress in compression much higher than that of high density foam. As shown in Figure 4, the insulating block 10 is provided with a cover panel 13 covering the upper surface 4 of the foam pad 1 and a bottom panel 14 covering the opposite surface, for example plywood. In embodiments, it is also possible to remove the cover panel 13 and / or the bottom panel 14. The bottom panel 14 is for example wood plywood 9mm thick. Such a panel allows a better distribution of the compressive stresses and limits the local deterioration of the foam. The compression stresses applied to the insulation are due to the static and dynamic pressure of the LNG of the tank. The bottom panel 14 may also be made of composite material resistant to bending and shearing. The assembly between the bottom panel 14 and the insulating block 10 is made by gluing. The cover panel 13 adhered to the upper part of the insulating block 30 can be made in the same way and can also be used, if necessary, to distribute the compressive stresses. Thus, the cutting of the insulating block 10 is optimized so as to limit as far as possible the thermal chimneys present between the foam blocks. Preferably, the only games present are the mounting sets and the passages of the fasteners in the corners. FIG. 5 shows a variant of the insulating block 10. The elements similar or identical to those of FIG. 1 bear the same reference numeral 5 increased by 100. In this variant, the cover panel 113 has two additional elements: a counterbore 15 quarter-disc shape is present at each corner to accommodate without forming a thicker plate of an anchoring member, which will be described below; Two parallel grooves 16 are dug into the cover panel 113 to accommodate metal strips for welding a waterproofing membrane formed of raised-edge strakes made of a low-expansion alloy, according to the known art. FIG. 6 represents another variant of the insulating block 10. The elements 15 similar or identical to those of FIG. 1 bear the same reference numeral increased by 200. The cover panel 213 carries a metal anchoring strip 18 fixed on its upper surface in a counterbore without forming excess thickness. This anchor strip 18 is used to weld the edge of a corrugated thin sheet metal plate to form a sealing membrane according to another technique. In this variant, the cover panel 213 may also present the countersinks 15. The corner pillars 205 may be similar to the pillars 5 or 105. Referring to FIG. 7, an embodiment of a structure of watertight and thermally insulating tank wall, shown in broken perspective to show the structure of this wall. Such a structure 25 may be implemented on large surfaces having various orientations, for example to cover bottom, ceiling and side walls of a tank. The orientation of Figure 1 is not limiting in this regard. The tank wall is attached to the wall of a supporting structure 20. By convention, a "position" will be called "above" a position located closer to the inside of the tank and "below" a position located closer to the tank. carrier structure 1, regardless of the orientation of the vessel wall relative to the earth's gravity field.

The vessel wall comprises a secondary insulating barrier 21, a secondary sealed barrier 22 retained on the top of the secondary insulating barrier 21, a primary insulating barrier 23 retained on the secondary sealed barrier 22 and a primary sealed barrier 24 retained on top of the secondary insulating barrier 22 the primary insulating barrier 23. The secondary insulating barrier 21 consists of a plurality of parallelepipedic secondary insulating blocks which are arranged side by side, so as to substantially cover the inner surface of the carrier structure 20. A secondary insulating block has, for example a length and a width of 3 m and 1 m respectively. It has a rectangular parallelepiped shape and consists of a polyurethane foam between two plywood plates. One of the plates protrudes at the periphery of the foam and is intended to rest on the carrier wall 20 with interposition of resin strands for catching local defects of the carrier wall 20. The other plate of the secondary insulation block comprises, along its two axes of symmetry, a metal bonding strip 26 which is fixed by screws, rivets, staples or glue. In the crossing zone of the strips 26, a continuous metal plate 27 has been arranged, which supports, in the center of the crossing of the strips, a pin 28 (FIG. 8) projecting above the secondary insulating barrier 21. A gap 30 is formed each time between two adjacent secondary blocks. Starting from the uncoated secondary insulating block shown at the top left of FIG. 7 and going in a direction oblique towards the right and towards the bottom, the perspective shows a secondary insulating block which is partially covered by a sheet part of the secondary sealing barrier 22 of the vessel wall. This metal sheet 31 has a substantially rectangular shape and comprises, in each of the two axes of symmetry of this rectangle, a fold 32a, respectively 32b. The folds 32a and 32b form reliefs arranged in the direction of the supporting wall 20 and they are housed in the interstices 30 of the secondary insulating barrier. The metal sheets 31 are made of invar®, whose coefficient of thermal expansion is typically between 1.5 × 10-6 and 2.10-6 K -1. They have a thickness of between about 0.7 mm and about 0.4 mm. Two adjacent plates 31 are welded together, as will be described in FIG. 8. The plates 31 are held on the secondary insulating blocks with strips 26 on which at least two edges of each sheet 31 are welded. from the metal plates 31 of the secondary sealing barrier 22 and running obliquely to the right and downwards, it is seen that there is shown an area where the secondary sealing barrier 22 is covered with a primary insulation block 23 of the vessel wall. The insulation block 23 is preferably made in accordance with the insulation block 10 described above. The fixing of these insulating blocks 23 is carried out thanks to the studs 8 as represented in FIG. 8.

On the upper face of the insulating block 23, there are two connecting strips 18; these connecting strips are metallic and arranged in recesses in the insulating block 23 to avoid any extra thickness on the insulating block. The two strips 18 are arranged parallel to the borders of the block 23 and they are fixed in their recesses as previously described. Unlike the insulating block 10 described above, the insulating block 23 is cut on its upper surface by a square network of relaxation slots 35 which extend over a portion of the thickness of the insulating block 23 to limit contraction stresses thermal. However, such relaxation slots are not always necessary, depending on the properties of the material used to produce the insulating blocks and the thermal stresses applied to them. Finally, Figure 7 shows, when moving from a block 23 obliquely downward and to the right, the establishment of a metal sheet 24 constituting the primary sealing barrier of the tank. This sheet 24 may be made of stainless steel with a thickness of about 1.2 mm; it comprises folds arranged along axes parallel to its edges. These folds may be raised on the side of the bearing wall 20, but they may also be raised towards the inside of the tank; these folds have been designated by 29. In FIGS. 7 and 8, the folds 29 project inwards towards the vessel.

FIG. 8 shows the establishment of the primary insulating blocks 23 so that the corners of four blocks 23 meet each time around a stud 28 welded at its base on the plate 27 and threaded at its upper end to cooperate with a clamping bolt 39. This clamping bolt 39 is arranged, with the possible interposition of washers 37, at the bottom of a cup 38, the peripheral edge of which rests in the counterbores 15 made on the four primary insulation blocks 23 The bolt 28, the cup 38 and the nut 39 thus constitute an anchoring member which bears on the corner pillars 5 of the primary insulating blocks 23 in the direction of the bearing wall 20. The technique described above to achieve a sealed and insulating tank wall can be used in different types of tanks, for example to form the wall of an LNG tank in a land installation or in a floating structure as a ship m thanier or other. Figures 7 and 8 illustrate a particular way of producing the secondary element of the vessel wall. Those skilled in the art will appreciate that other structures are also usable for realizing the secondary insulating barrier and the secondary watertight barrier. In the embodiment of Figures 7 and 8, the studs 28 are attached to the secondary insulating barrier. In an alternative embodiment, anchoring members attached directly to the carrier wall extend through the entire secondary element and to the top of the primary insulating blocks and serve to retain the primary insulating blocks in a manner similar to the studs 28. Referring to Figure 13, a cutaway view of a LNG tanker 70 shows a sealed and insulated tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary sealed barrier intended to be in contact with the LNG contained in the tank, a secondary sealed barrier arranged between the primary waterproof barrier and the double hull 72 of the ship, and two insulating barriers arranged respectively between the primary watertight barrier and the secondary watertight barrier and between the secondary watertight barrier and the double hull 72. In a manner known per se, loading / unloading pipes 73 arranged on the upper deck of the ship may be connected, by means of appropriate connectors, at a marine or port terminal to transfer a cargo of LNG to or from the tank 71.

FIG. 13 represents an example of a marine terminal comprising a loading and unloading station 75, an underwater pipe 76 and an onshore installation 77. The loading and unloading station 75 is a fixed off-shore installation comprising an arm mobile 74 and a tower 78 which supports the movable arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79 that can connect to the loading / unloading pipes 73. The movable arm 74 can be adapted to all gauges of LNG carriers . A connection pipe (not shown) extends inside the tower 78. The loading and unloading station 75 enables the loading and unloading of the LNG tank 70 from or to the shore facility 77. liquefied gas storage tanks 80 and connecting lines 81 connected by the underwater line 76 to the loading or unloading station 75. The underwater line 76 allows the transfer of the liquefied gas between the loading or unloading station 75 and the onshore installation 77 over a large distance, for example 5 km, which makes it possible to keep the tanker vessel 70 at great distance from the coast during the loading and unloading operations. In order to generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and / or pumps fitted to the shore installation 77 and / or pumps fitted to the loading and unloading station 75 are used. Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it comprises all the technical equivalents of the means described and their combinations if These are within the scope of the invention. The use of the verb "to include", "to understand" or "to include" and its conjugated forms does not exclude the presence of other elements or steps other than those set out in a claim. The use of the undefined article "a" or "an" for an element or step does not exclude, unless otherwise stated, the presence of a plurality of such elements or steps. In the claims, any reference sign in parentheses can not be interpreted as a limitation of the claim.

Claims (20)

REVENDICATIONS1. Insulating block (10, 23) having a flattened overall prismatic shape for the manufacture of a sealed and insulating tank wall, the insulating block being intended to be arranged in a repeated pattern to form an insulating barrier 5 of the tank wall, the insulating block comprising: a pavement (1) of polymer foam with a density greater than 100 kg / m 3 having a polygonal upper surface (4), an identically polygonal lower surface parallel to the upper surface and spaced from the upper surface in a direction of thickness of the insulating block and a plurality of side surfaces (3) extending between the upper surface and the lower surface perpendicular to the upper and lower surfaces, the polymeric foam pad having slits extending in the thickness direction of the insulation block at a plurality of angles of the upper and lower surfaces so as to form a plurality of on corner faces (2) which each extend between two adjacent side surfaces (3) of the block, and a plurality of corner pillars (5, 105, 205, 405, 505, 605) attached to the block polymeric foam in the cuts and extending the entire thickness of the insulating block between the upper and lower surfaces, wherein the corner pillars (5, 105, 205) are made of a material which has a coefficient of thermal expansion between 75% and 125% of the coefficient of thermal expansion of the polymer foam constituting the block and which has a yield strength in compression greater than 1.5 MPa, preferably greater than 3 MPa, at a temperature of 23 ° C the corner pillar having in each case an inner side surface (6, 106, 406, 506, 606) completely covering a corner surface (2) of the polymeric foam pad, the inner side surface of the pillar angle being glued to the corner surface. An insulation block according to claim 1, wherein the polymeric foam constituting the pad (1) is a closed-cell polyurethane foam of density greater than or equal to 130kg / m3. 3. Insulating block according to one of claims 1 to 2, wherein the material of the corner pillars (5, 105, 205) is a polymer foam of density greater than or equal to 170 kg / m3. 4. Insulating block according to one of claims 1 to 2, wherein the material of the corner pillars (5, 105, 205) comprises a polymer resin. An insulation block according to one of claims 1 to 4, further comprising a plywood cover panel (13) secured to the upper surface of the polymeric foam pad, the cover panel covering in the corners an upper surface of the pillars. angle, the cover panel having an outline aligned with the side surfaces of the polymer foam pad and with the lateral outer surface of the corner pillars attached to the pad. An insulation block according to claim 5, wherein the cover panel has a plurality of countersinks (15) disposed above each of the corner pillars. An insulation block according to one of claims 1 to 6, further comprising a plywood bottom panel (14) secured beneath the bottom surface of the polymeric foam pad, the bottom panel overlapping in the corners a bottom surface of the corner pillars, the bottom panel having an outline aligned with the side surfaces of the polymeric foam pad and with the outer side surface of the corner pillars attached to the pad. 8. Insulating block according to one of claims 1 to 7, wherein a corner pillar (5, 105, 205) has in each case a constant sectional shape 20 in a plane perpendicular to the direction of thickness, the sectional shape having an outer edge set back from the intersection geometrical point of the two side surfaces of the block which are adjacent to the corner surface on which the pillar is fixed. Insulating block according to claim 8, wherein the corner surface (2) of the block is flat and in which the sectional shape of the pillar (5) is a trapezium having a large base which corresponds to the inner side surface. (6) of the pillar, a small base which corresponds to the outer edge set back from the intersection geometric point of the two lateral surfaces of the pavement, and two inclined side respectively located in alignment with the two lateral surfaces of the pavement which are adjacent to the corner surface on which the pillar is fixed. Insulating block according to claim 8, wherein the corner surface of the block is rounded, the sectional shape of the pillar (105) being a corner sector of a disc whose tip is cut along a straight line which corresponds to the edge outside set back from the geometric point of intersection of the two side surfaces (3) of the block, the two radial sides delimiting the angular sector being respectively located in alignment with the two side surfaces of the block which are adjacent to the surface of the block; angle on which the pillar is fixed. An insulating block according to one of claims 1 to 10, wherein the lower surface and the upper surface (4) of the polymeric foam pad are generally rectangular, the insulating pad having an overall rectangular parallelepipedal shape. An insulating block according to one of claims 1 to 11, wherein the inner side surface (406, 506, 606) comprises a hook member (420, 520, 620) projecting transversely from the corner post ( 405, 505, 605) to the polymer foam pad, the catcher comprising a section in a plane parallel to the thickness of the insulating block of small area relative to a total area of the inner side surface. An insulation block according to claim 12, wherein the hooking member (620) extends along the entire length of the corner post and protrudes over a small portion of the periphery of the corner post. 20 Insulating block according to claim 12, wherein the hooking element extends over a small portion of the length of the corner pillar. An insulation block according to one of claims 12 to 14, wherein the inner side surface comprises a plurality of juxtaposed attachment members (420, 520, 620). 25 An insulation block according to claim 15, wherein two successive tie members (420, 520) of the plurality are spaced (422, 522) on the inner side surface. 17. Sealed and thermally insulating vessel arranged in a bearing structure for containing a cold fluid, in which the wall of the vessel comprises successively in a direction of thickness a primary waterproof membrane (24) intended to be in contact with the fluid, a primary insulating barrier (23), a secondary waterproofing membrane (22) and a secondary insulating barrier (21) disposed between the secondary waterproofing membrane and the supporting structure, in which the primary insulating barrier comprises a set of insulating blocks (23) according to one of claims 1 to 16 juxtaposed to form a flat support surface for the primary waterproof membrane, the upper surface of the insulating blocks being turned towards the inside of the tank, the wall of the tank further comprising anchoring (28, 37, 38, 39) for retaining the insulating blocks (23) on the secondary waterproof membrane, an anchoring member having in each case an element of a ppui (38) engaged on the upper surface (4) of the insulating block in line with a corner pillar (5, 105, 205) and a connecting element (28) disposed between the insulating blocks juxtaposed, attached to the support element and extending from the support element in the thickness direction of the insulating blocks (23) towards the supporting structure (20), the connecting element being attached to the insulating barrier secondary (21, 20) or the carrier structure 15 to press the insulating blocks (23) on the secondary waterproof membrane (22). 18. Ship (70) for the transport of a cold liquid product, the vessel having a double hull (72) and a tank (71) according to claim 17 disposed in the double hull. 19. A method of loading or unloading a vessel (70) according to claim 18, wherein a cold liquid product is conveyed through insulated pipelines (73, 79, 76, 81) to or from a floating storage facility. or terrestrial (77) to or from the vessel vessel (71). 20. Transfer system for a cold liquid product, the system comprising a ship (70) according to claim 18, insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the vessel hull at a floating or land storage facility (77) and a pump for driving a flow of cold liquid product through the insulated pipelines from or to the floating or land storage facility to or from the vessel vessel.