AU2014252951B2

AU2014252951B2 - Insulating block for producing a sealed and insulated tank wall

Info

Publication number: AU2014252951B2
Application number: AU2014252951A
Authority: AU
Inventors: Bruno Deletre; Mickael Herry; Antoine PHILIPPE; Nicolas THENARD
Original assignee: Gaztransport et Technigaz SA
Current assignee: Gaztransport et Technigaz SA
Priority date: 2013-04-11
Filing date: 2014-03-27
Publication date: 2018-10-25
Anticipated expiration: 2034-03-27
Also published as: CN105143752B; MY178330A; KR102181506B1; FR3004508B1; AU2014252951A1; WO2014167206A1; EP2984381A1; KR20150142032A; CN105143752A; FR3004508A1

Abstract

An insulating block (10) having a generally flattened prismatic shape for producing a sealed and insulated tank wall, comprising: a polymer foam pad (1) of which the density is greater than 100kg/m

Description

Technical Field

The invention relates to the field of leaktight and thermally insulating tanks arranged in a carrying structure in order to contain a cold liquid, in particular to tanks with a membrane for containing liquefied gases.

Technological Background

Leaktight and thermally insulating tanks arranged in the hull of a ship for transporting a 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 constructed in a modular form with the aid of juxtaposed parallelepipedal wooden boxes. The boxes are filled with thermally insulating packing of expanded perlite or aerogel materials.

FR-A-2978748 discloses another LNG tank arranged in the hull of a ship, in which a secondary insulating barrier comprises insulating blocks arranged according to a repeated pattern. The insulating block comprises an overall flattened parallelepipedal pad of high-density polymer foam having cutouts 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 flats which in each case extend between two adjacent lateral surfaces of the pad. A corner post is fixed to the polymer foam pad at each cut flat, and extends over the entire thickness of the insulating block between the upper and lower surfaces in order to take up a part of the compressive force and thus limit the creep and squeezing of the foam.

Summary

One idea on which the invention is based is to provide insulating blocks suitable for producing in a relatively simple way a primary insulating barrier of a leaktight and thermally insulating tank, the service lifetime of which is long.

According to one embodiment, the invention provides an insulating block having an overall shape of a flattened prism for producing a leaktight and insulating tank wall, the insulating block being intended to be arranged according to a repeated pattern in order to form an insulating barrier of the tank wall, the insulating block comprising:

a pad of polymer foam with a density of more than 100 kg/m³, having a polygonal upper surface, an identically polygonal lower surface parallel to the upper surface and separated from the upper surface in a thickness direction of the insulating block, and a plurality of lateral surfaces extending between the upper surface and the lower surface perpendicularly to the upper and lower surfaces, the polymer foam pad having cutouts extending in the thickness direction of the insulating block at a plurality of corners of the upper and lower surfaces, so as to form a plurality of corner surfaces which in each case extend between two adjacent lateral surfaces of the pad, and a plurality of corner posts fixed to the polymer foam pad in the cutouts and extending over the entire thickness of the insulating block between the upper and lower surfaces, wherein the corner posts are made of a material which has, in particular in the thickness direction of the insulating block, a thermal expansion coefficient of between 75% and 125% of the thermal expansion coefficient of the polymer foam constituting the pad, and which has an elastic limit in compression of more than 1.5 MPa, and preferably more than 3 MPa, at a temperature of 23°C, the corner post having in each case an inner lateral surface fully covering a corner surface of the polymer foam pad, the inner lateral surface of the corner post being fixed, for example adhesively bonded, to the corner surface.

When the corner post is assembled by adhesive bonding with the foam pad at an ambient temperature, and when the insulating block is subsequently used at a much lower temperature, for example in an insulating barrier of a liquefied natural gas tank wall, and particularly in the primary barrier of such a tank, the differential thermal contraction is liable to create shear stresses in the adhesively bonded interface. By virtue of the selection of the thermal expansion coefficient of the corner post, it is thus possible to limit these stresses in order to improve the solidity and longevity of the adhesively bonded assembly. Similar advantages are obtained when the assembly of the corner post with the pad is carried out in another way, for example using clamps.

Furthermore, the elastic limit in compression of the corner post makes it possible to limit the displacement by creep of this post to an acceptable level, in particular to a level less than the displacement capable of being elastically absorbed by anchoring members retaining the insulating block on the carrying structure of the tank wall.

According to some embodiments, such an insulating block may have one or more of the following characteristics.

According to one embodiment, the polymer foam constituting the pad is a closed-cell polyurethane foam with a density greater than or equal to 130 kg/m³.

According to one embodiment, the material of the corner posts is a polymer foam with a density greater than or equal to 170 kg/m³, for example 210 kg/m³. Preferably, in this case, the corner post is a full solid structure.

According to one embodiment, the material of the corner posts is a polymer resin. Preferably, in this case, the corner post is a hollow structure.

According to one embodiment, the material of the corner posts is a composite which may comprise fibers embedded in a polymer resin. Preferably, in this case, the corner post is a hollow structure.

According to one embodiment, the insulating block furthermore comprises a plywood cover panel fixed on the upper surface of the polymer foam pad, the cover panel covering in the corners an upper surface of the corner posts, the cover panel having a contour aligned with the lateral surfaces of the polymer foam pad and with the outer lateral surface of the corner posts fixed to the pad.

According to one embodiment, the cover panel has a plurality of recesses arranged above each of the corner posts.

According to one embodiment, the insulating block furthermore comprises a plywood bottom panel fixed under the lower surface of the polymer foam pad, the bottom panel covering in the corners a lower surface of the corner posts, the bottom panel having a contour aligned with the lateral surfaces of the polymer foam pad and with the outer lateral surface of the corner posts fixed to the pad.

According to one embodiment, a corner post in each case has a constant cross-sectional shape in a plane perpendicular to the thickness direction, the crosssectional shape having an outer edge set back from the geometrical point of intersection of the two lateral surfaces of the pad which are adjacent to the corner surface on which the post is fixed.

According to one embodiment, the corner surface of the pad is plane, and the cross-sectional shape of the post is a trapezoid having a long base which corresponds to the inner lateral surface of the post, a short base which corresponds to the outer edge set back from the geometrical point of intersection of the two lateral surfaces of the pad, and two inclined sides respectively in alignment with the two lateral surfaces of the pad which are adjacent to the corner surface on which the post is fixed.

According to one embodiment, the corner surface of the pad is rounded, the cross-sectional shape of the post being an angular sector of a disk whose vertex is cut along a straight line which corresponds to the outer edge set back from the geometrical point of intersection of the two lateral surfaces of the pad, the two radial sides delimiting the angular sector respectively being in alignment with the two lateral surfaces of the pad which are adjacent to the corner surface on which the post is fixed.

According to one embodiment, the lower surface and the upper surface of the polymer foam pad are overall rectangular, the insulating block having an overall rectangular parallelepipedal shape.

According to one embodiment, the inner lateral surface comprises a hook element projecting transversely from the corner post toward the polymer foam pad, the hook element comprising a cross section in a plane parallel to the thickness of the insulating block which has a small surface area in comparison with a total surface area of the inner lateral surface.

By virtue of these characteristics, the surface area of the anchoring of the corner post to the polymer foam pad is increased, improving the technical characteristics of the assembly, the bonding strength.

According to one embodiment, the hook element extends over the entire length of the corner post and projects over a small portion of the periphery of the corner post.

According to one embodiment, the hook element extends over a small portion of the length of the corner post.

According to one embodiment, the inner lateral surface comprises a plurality of juxtaposed hook elements.

According to one embodiment, two successive hook elements of the plurality are spaced apart on the inner lateral surface.

According to one embodiment, at least two successive hook elements of the plurality are adjacent.

According to one embodiment, the post comprises a support segment oriented along the thickness of the insulating block, and a hook element fixed by its base on the support segment of the corner post.

According to one embodiment, the hook element comprises a toothed profile.

According to one embodiment, the hook element comprises a spherical portion.

According to one embodiment, the hook element comprises a cylindrical portion.

According to one embodiment, the invention also provides a leaktight and thermally insulating tank arranged in a carrying structure in order to contain a cold fluid, wherein the wall of the tank successively comprises in a thickness direction a primary leaktight membrane intended to be in contact with the fluid, a primary insulating barrier, a secondary leaktight membrane, and a secondary insulating barrier arranged between the secondary leaktight membrane and the carrying structure, wherein the primary insulating barrier comprises a set of aforementioned insulating blocks juxtaposed in order to form a plane support surface for the primary leaktight membrane, the upper surface of the insulating blocks facing toward the interior of the tank, the wall of the tank furthermore comprising anchoring members for retaining the insulating blocks on the secondary leaktight membrane, an anchoring member in each case comprising a bearing element engaging on the upper surface of the insulating block in line with a corner post and a connecting element arranged between the juxtaposed insulating blocks, attached to the bearing element and extending from the bearing element in the thickness direction of the insulating blocks in the direction of the carrying structure, the connecting element being attached to the secondary insulating barrier or to the carrying structure in order to press the insulating blocks onto the secondary leaktight membrane.

By virtue of these characteristics, the corner post helps to take up some of the compressive forces in order to limit the squeezing and the creep of the polymer foam during use.

Such a tank may form part of a onshore storage installation, for example for storing LNG, or it may be installed in a floating structure, on the coast or in deep water, in particular a methane tanker ship, a floating storage and regasification unit (FSRU), a floating production and remote storage unit (FPSO) and the like.

According to one embodiment, a ship for transporting a cold liquid product comprises a double hull and an aforementioned tank arranged in the double hull.

According to one embodiment, the invention also provides a method for loading or unloading such a ship, wherein a cold liquid product is conveyed through insulated pipelines from or to a floating or onshore storage installation 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 aforementioned ship, insulated pipelines arranged in order to connect the tank installed in the hull of the ship to a floating or onshore storage installation, and a pump for driving a flow of cold liquid product through the insulated pipelines from or to the floating or onshore storage installation to or from the tank of the ship.

Certain aspects of the invention are based on the idea of providing a relatively high safety margin, for example of the order of 5 to 10 or more, between on the one hand the compressive stress typically exerted on the corner of an insulating block in the primary insulating barrier of a membrane tank for a methane tanker, and on the other hand the elastic limit in compression of the material constituting the corner posts of such an insulating block.

Certain aspects of the invention are based on the idea of increasing the strength of the fastening subject to thermal variations between the foam pad and each corner post. Certain aspects of the invention are based on the idea of increasing the surface area of the interface between the foam pad and the inner lateral surface of a corner post.

Brief description of the figures

The invention will be understood more clearly, and other objects, details, characteristics and advantages thereof will become clearer from the following description of several particular embodiments of the invention, which are given solely by way of illustration and without implying limitation, with reference to the appended drawings.

• Figure 1 is a three-quarter view in perspective of an insulating block according to one embodiment.

• Figure 2 is a similar view to Figure 1 showing a foam pad of the insulating block.

• Figure 3 is an enlarged perspective view of a corner post of the insulating block of Figure 1.

• Figure 4 is a view in cross section of a corner post according to another embodiment.

• Figure 5 is a view from above of an insulating block according to another embodiment.

• Figure 6 is a partial three-quarter perspective view of an insulating block according to another embodiment.

• Figure 7 is a cutaway perspective view of a leaktight and insulating wall of a storage tank for liquefied gas.

• Figure 8 is an enlarged perspective view of the primary element of the wall of Figure 7.

• Figure 9 is a view from above of a corner post according to another embodiment.

• Figure 10 is a view of an insulating block in section along the line A-A of Figure 9.

• Figure 11 is a side view of a corner post according to another embodiment.

• Figure 12 is a view from above of a corner post according to another embodiment.

• Figure 13 is a cutaway schematic representation of a methane tanker ship tank and a terminal for loading/unloading this tank.

Detailed description of embodiments

Referring to Figure 1, an insulating block 10 has the overall shape of a flattened rectangular parallelepiped with cut flats 12 in the corners in order to allow the fastening members, which will be described below, to pass through.

The core of the insulating block 10 consists of a foam pad 1 represented 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 thermal expansion coefficient of about 6.10^-5 m/m/K. Each corner of the foam pad 1 between two adjacent lateral surfaces 3 is chamfered at 45° so as to have a plane corner surface 2 interposed between two lateral surfaces 3.

A corner post 5 represented in Figure 3 is in each case fixed, for example adhesively bonded, on the corner surface 2 of the foam pad 1. The corner post 5 has the shape of a prism with a trapezoidal base. The surface 6 of the prism which corresponds to the long base of the trapezoid is the one which comes in contact with the corner surface 2. The opposite surface 7, which corresponds to the short base of the trapezoid, forms the cut flat 12 of the insulating block 10. The two inclined surfaces 8 are mutually perpendicular and are each aligned with a lateral surface 3 of the foam pad 1.

Figure 4 represents a variant of the corner post. The elements which are similar or identical to those of Figure 3 have the same reference number increased by 100. In this variant, the corner post 105 has the shape of a prism whose base is a cut quarter of a cylinder. Thus, the rear surface 106 intended to be in contact with the foam block 1 has the shape of a quarter cylinder. The corner surfaces 2 of the foam block 1 must be modified in the same way in this case. Thus, the surface area available for carrying out adhesive bonding is greater in the case of the corner post 105.

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

Figure 10 illustrates a corner post 405 assembled with the insulating block, along the section A-A of Figure 9. The corner post 405 has two protuberances 420 separated by a connecting portion 422. This figure 10 shows that the cross section of the protuberances 420 in the shape of a tongue is rectangular. It also shows that the surface area of the base 421 of the protuberance 420 is small compared with the total surface area of the rear surface 406.

By virtue of these protuberances 420, the corner post 405 has a rear surface 406 of contact with the foam block 1 which is larger than that of the post 5. In order to allow assembly, the interface between the rear surface 406 of the corner post 405 and the corner surfaces 2 of the foam block 1 are adapted so that the corner surfaces 2 match that of the rear surface 406. The protuberances 420 are then embedded in the foam block 1. The increase of the rear surface 406 increases the contact surface between the post 405 and the foam block 1. This increases the strength of the assembly, for example in the case of an adhesively bonded assembly.

Figure 11 represents a variant of the corner post. The elements which are similar or identical to those of Figure 9 have the same reference number increased by 100. In this variant, the corner post 505 comprises three protuberances 520. These have a cross section corresponding to a circular portion.

As a variant, the protuberances 520 or 420 are localized, for example, on a part of the width of the rear surface 506 or 406 of the post 505 or 405.

Figure 12 represents a variant of the corner post. The elements which are similar or identical to those of Figure 9 have the same reference number increased by 200. In this variant, the rear surface 606 of the corner post 605 comprises five protuberances 620 oriented along the thickness direction of the insulating block 10.

The protuberances 620 are adjacent to one another so as to form the rear surface

606.

As a variant of the embodiments of Figures 9 to 12, the protuberances 420, 520 or 620 may be localized, 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 post 405, 505 or 605, as well as that of the corner surfaces 2 of the foam block 1. The stresses are localized.

The use of continuous protuberances 420, 520 or 620 makes implementation more complex. It has the benefit of greatly increasing the rear assembly surfaces 406, 506 or 606 and therefore of limiting the anchoring forces in the interface.

In one variant which is not represented, the protuberances 420, 520 or 620 are not produced in one piece with the corner post 405, 505 or 605, but are attached onto a segment of the post 405, 505 or 605 in order to form the rear surface 406, 506 or 606. They are then fixed, for example, by adhesive bonding or clamping.

The corner post 5, 105, 405, 505 or 605 may be made of glass fiberreinforced polyurethane foam having a density of 210 kg/m³, which has an elastic limit in compression 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, like the foam 3. One of the advantages of using polyurethane foam is the thermal conductivity of this material, of the order of from 0.030 to 0.035 W/mK at 20°C.

An elastic limit in compression higher than 1.5 MPa at 23°C would be satisfactory in view of two facts:

• The elastic limit in compression of the polymer foam before damage increases when the temperature decreases (by about a factor of 2 between 23°C and-170°C).

• Creep of the foam takes place over time and may result both in tensioning of the retaining members at ambient temperature and forces experienced throughout the period of use of the ship when cold (between -100 and 170°C for the primary). For this reason, the strength at ambient temperature and the cold strength are both relevant when selecting the insulating material.

As a variant, the corner post 5, 105, 405, 505 or 605 may be made of polymer resin or composite material in the form of a hollow tube, the upper and lower ends of which are open or closed. The presence of a closure surface on the end has the advantage of distributing better the compressive load received by the insulating block 10 during use. By way of example, it is possible to use polyetherimide (PEI), the thermal contraction coefficient of which is 45.1 O'⁶ m/mK with a stress at the elastic limit in compression at 23°C of the order of 110 MPa, polyethylene terephthalate (PET), the thermal contraction coefficient of which is 65.1 O'⁶ m/mK with a stress at the elastic limit in compression at 23°C of the order of 80 MPa, or polypropylene (PP), or polyethylene (PE) weakly filled with fibers in order to reduce the thermal contraction coefficient into the range of from 45 to 75.10' ⁶ m/mK with a stress at the elastic limit in compression much higher than that of high-density foam.

As can be seen 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 made of plywood. In some embodiments, it is also possible to omit the cover panel 13 and/or the bottom panel 14.

The bottom panel 14 is, for example, made of plywood with a thickness of 9 mm. Such a panel allows better distribution of the compressive stresses and limits the local degradation of the foam. The compressive stresses applied to the insulation are due to the static and dynamic pressure of the LNG in the tank. The bottom panel 14 may also be made of a composite material resistant to flexion and shearing. The assembly between the bottom panel 14 and the insulating block 10 is carried out by adhesive bonding.

The cover panel 13 adhesively bonded onto the upper part of the insulating block 10 may be made in the same way and is also used, optionally, to distribute the compressive stresses.

Thus, the contour of the insulating block 10 is optimized so as to minimize the thermal paths present between the foam blocks. Preferably, the only plays present are the mounting plays and the passages of the fastening members in the corners.

Figure 5 represents a variant of the insulating block 10. The elements which are similar or identical to those of Figure 1 have the same reference number increased by 100. In this variant, the cover panel 113 has two additional elements:

- a recess 15 in the shape of a quarter disk is present in each corner in order to receive, without forming an overthickness, a plate of an anchoring member which will be described below;

- two parallel grooves 16 are hollowed in the cover panel 113 in order to receive metal bands intended to weld a sealing membrane formed by strakes with raised edges made of alloy with a low expansion coefficient, according to the known technique.

Figure 6 represents another variant of the insulating block 10. The elements which are similar or identical to those of Figure 1 have the same reference number increased by 200. The cover panel 213 carries a metal anchoring band 18 fixed on its upper surface in a recess without forming an overthickness. This anchoring band 18 makes it possible to weld the edge of a thin corrugated metal plate in order to form a sealing membrane according to another technique. In this variant, the cover panel 213 may also have the recesses 15. The corner posts 205 may be similar to the posts 5 or 105.

With reference to Figure 7, an exemplary embodiment of a leaktight and thermally insulating tank wall structure, represented in cutaway perspective in order to show the structure of this wall, will now be described. Such a structure may be used on extended surfaces having various orientations, for example in order to cover bottom, roof and side walls of a reservoir. The orientation of Figure 1 is therefore not limiting in this regard.

The tank wall is attached to the wall of a carrying structure 20. By convention, “above” will refer to a position lying closer to the interior of the reservoir, and “below” will refer to a position lying closer to the carrying structure 1, regardless of the orientation of the tank wall relative to the Earth’s gravitational field.

The tank wall comprises a secondary insulating barrier 21, a secondary sealing barrier 22 held on the top of the secondary insulating barrier 21, a primary insulating barrier 23 held on the secondary sealing barrier 22, and a primary sealing barrier 24 held on the top of the primary insulating barrier 23.

The secondary insulating barrier 21 consists of a plurality of parallelepipedal secondary insulating blocks which are arranged side by side, so as to substantially cover the internal surface of the carrying structure 20. A secondary insulating block has for example a length and a width, respectively of 3 m and 1 m. It has a rectangular parallelepipedal shape and it consists of a polyurethane foam contained between two plywood plates. One of the plates extends beyond the periphery of the foam and is intended to bear on the carrying wall 20 with the interposition of resin beads intended to compensate for the local defects of the carrying wall 20. The other plate of the secondary insulation block comprises, along its two symmetry axes, a metal connecting band 26 which is fixed by screws, rivets, clamps or adhesive. In the crossover region of the bands 26, a continuous metal plate 27 has been arranged, which, at the center of the crossover of the bands, supports a pin 28 (Figure 8) projecting above the secondary insulating barrier 21. A gap 30 is formed in each case between two adjacent secondary blocks.

Starting with the uncovered secondary insulating block represented at the top left in Figure 7, and continuing in an oblique direction toward the right and downward, the perspective shows a secondary insulating block which is partially covered with a metal sheet 31 constituting a part of the secondary sealing barrier 22 of the tank wall. This metal sheet 31 has a substantially rectangular shape and, along each of the two symmetry axes of this rectangle, it comprises a crease 32a, 32b, respectively. The creases 32a and 32b form reliefs arranged in the direction of the carrying wall 20 and they are arranged in the gaps 30 of the secondary insulating barrier. The metal sheets 31 are made of Invar®, the thermal expansion coefficient of which is typically between 1.5.1 O'⁶ and 2.1 O'⁶ K'¹. They have a thickness of between about 0.7 mm and about 0.4 mm. Two adjacent metal sheets 31 are welded together with overlap, as will be described in Figure 8. The holding of the metal sheets 31 on the secondary insulating blocks is carried out with the bands 26, onto which at least two edges of each metal sheet 31 are welded.

Starting with the metal sheets 31 of the secondary sealing barrier 22 and continuing obliquely toward the right and downward, it can be seen that a region in which the secondary sealing barrier 22 is covered with a primary insulation block 23 of the tank wall has been represented. The insulation bloc 23 is preferably produced according to the insulating block 10 described above. The fastening of these insulating blocks 23 is carried out using the pins 8, as represented in Figure 8.

On the upper face of the insulating block 23, there are two connecting bands 18; these connecting bands are made of metal and are arranged in grooves formed in the insulating block 23 in order to avoid any overthickness on this insulating block. The two bands 18 are arranged parallel to the borders of the block 23, and they are fixed in their grooves as described above.

Unlike the insulating block 10 described above, the insulating block 23 is cut on its upper surface by a square array of relaxation slots 35, which extend over a part of the thickness of the insulating block 23 in order to limit the thermal contraction stresses. Such relaxation slots, however, are not always necessary, depending on the properties of the material used to produce the insulating blocks and the thermal stresses which are applied to them.

Lastly, Figure 7 shows, when moving from a block 23 obliquely downward and toward the right, the placement 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 creases arranged along axes parallel to its edges. These creases may be in relief on the side of the carrying wall 20, although they may also be in relief toward the interior of the tank; these creases have been denoted by 29. In Figures 7 and 8, the creases 29 project toward the interior of the tank.

Figure 8 shows the placement of the primary insulating blocks 23 in such a way that the corners of four blocks 23 join in each case around a pin 28 welded at its base onto the plate 27 and screw-threaded at its upper end in order to cooperate with a tightening bolt 39. This tightening bolt 39 is arranged, with the optional interposition of washers 37, at the bottom of a cup 38, the peripheral border of which rests in the recesses 15 made on the four primary insulating blocks 23. The pin 28, the cup 38 and the nut 39 thus constitute an anchoring member which exerts pressure on the corner posts 5 of the primary insulating blocks 23 in the direction of the carrying wall 20.

The technique described above for producing a leaktight and insulating tank wall may be used in various types of reservoirs, for example in order to constitute the wall of an LNG reservoir in a onshore installation or in a floating structure such as a methane tanker ship or the like. Figures 7 and 8 illustrate a particular way of producing the secondary element of the tank wall. The person skilled in the art will understand that other structures may also be used in order to produce the secondary insulating barrier and the secondary leaktight barrier.

In the embodiment of Figures 7 and 8, the pins 28 are attached to the secondary insulating barrier. In an alternative embodiment, anchoring members attached directly to the carrying wall extend through the entire secondary element as far as the top of the primary insulating blocks and are used to hold the primary insulating blocks in a similar way to the pins 28.

Referring to Figure 13, a cutaway view of a methane tanker ship 70 shows a leaktight and insulated tank 71 of prismatic overall shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary leaktight barrier intended to be in contact with the LNG contained in the tank, a secondary leaktight barrier arranged between the primary leaktight barrier and the double hull 72 of the ship, and two insulating barriers arranged respectively between the primary leaktight barrier and the secondary leaktight barrier and between the secondary leaktight barrier and the double hull 72.

In a manner known per se, loading/unloading pipelines 73 arranged on the upper deck of the ship may be connected by means of suitable connectors to a maritime or port terminal in order to transfer an LNG cargo from or to the tank 71.

Figure 13 represents an example of a maritime terminal comprising a loading and unloading station 75, a submarine pipe 76 and a land installation 77. The loading and unloading station 75 is a fixed offshore installation comprising a mobile arm 74 and a tower 78 which supports the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible tubes 79 which can be connected to the loading/unloading pipelines 73. The mobile arm 74 fits all the gauges of methane tankers. A connecting pipe (not shown) extends inside the tower 78. The loading and unloading station 75 makes it possible to load and unload the methane tanker 70 from or to the land installation 77. The latter comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the submarine pipe 76 to the loading or unloading station 75. The submarine pipe 76 makes it possible to transfer the liquefied gas between the loading or unloading station 75 and the land installation 77 over a large distance, for example 5 km, which makes it possible to keep the methane tanker ship 70 at a large distance from the shore during the loading and unloading operations.

In order to generate the pressure necessary for transferring the liquefied gas, pumps installed on-board the ship 70 and/or pumps installed in the land installation 77 and/or pumps installed in the loading and unloading station 75 are used.

Although the invention has been described in connection with a plurality of particular embodiments, it is clear that it is in no way limited thereto and that it encompasses all the technical equivalents of the means described, as well as their combinations, if these fall within the scope of the invention.

The use of the verb “have”, “comprise” or “include” and its conjugated forms does not exclude the presence of other elements or other steps than those mentioned in a claim. The use of the indefinite article “a” or “an” for an element or a step does not, unless otherwise indicated, exclude the presence of a plurality of such elements or steps.

In the claims, any reference between brackets may not be interpreted as a limitation of the claim.

2014252951 25 Sep 2018

Claims

1. An insulating block (10, 23) having an overall shape of a flattened rectangular parallelepipedal prism for producing a leaktight and insulating tank wall, the insulating block being intended to be arranged according to a repeated pattern in order to form an insulating barrier of the tank wall, the insulating block comprising: a pad (1) of polymer foam with a density of more than 100 kg/m³, having an overall rectangular polygonal upper surface (4), an identically overall rectangular polygonal lower surface parallel to the upper surface and separated from the upper surface in a thickness direction of the insulating block, and a plurality of lateral surfaces (3) extending between the upper surface and the lower surface perpendicularly to the upper and lower surfaces, wherein the lateral surfaces (3) define a rectangular geometrical envelope of the upper and lower surfaces, the polymer foam pad having a plurality of corner surfaces (2) which extend between two adjacent lateral surfaces (3) of the pad and in the thickness direction of the insulating block, and which are short in comparison with the adjacent lateral surfaces (3) of the pad, the corner surfaces (2) being formed by cutouts cutting the rectangular geometrical envelope of the upper and lower surfaces in the thickness direction of the insulating block at a plurality of corners of the rectangular geometrical envelope of the upper and lower surfaces, and a plurality of corner posts (5, 105, 205, 405, 505, 605) fixed to the polymer foam pad in the cutouts and extending over the entire thickness of the insulating block between the upper and lower surfaces, each corner post having an inner lateral surface (6, 106, 406, 506, 606) fully covering a corner surface (2) of the polymer foam pad, wherein the corner posts (5, 105, 205) are made of a material which has a thermal expansion coefficient of between 75% and 125% of the thermal expansion coefficient of the polymer foam constituting the pad, and which has an elastic limit in compression of more than 1.5 MPa, , at a temperature of 23°C, the inner lateral surface of the corner post being adhesively bonded to the corner surface, and wherein the material of the corner posts (5, 105, 205) is selected from a group consisting of a polymer foam with a density greater than or equal to 170 kg/m³ and a polymer resin,

2014252951 25 Sep 2018 wherein each corner post (5, 105, 205) has a constant cross-sectional shape in a plane perpendicular to the thickness direction, the cross-sectional shape having an outer edge set back from a geometrical point of intersection of the two lateral surfaces of the pad which are adjacent to the corner surface on which the post is fixed, and wherein the corner surface of the pad is rounded, the cross-sectional shape of the post (105) being an angular sector of a disk whose vertex is cut along a straight line which corresponds to the outer edge set back from the geometrical point of intersection of the two lateral surfaces (3) of the pad, two radial sides delimiting the angular sector respectively being in alignment with the two lateral surfaces of the pad which are adjacent to the corner surface on which the post is fixed.

2. An insulating block (10, 23) having an overall shape of a flattened rectangular parallelepipedal prism for producing a leaktight and insulating tank wall, the insulating block being intended to be arranged according to a repeated pattern in order to form an insulating barrier of the tank wall, the insulating block comprising: a pad (1) of polymer foam with a density of more than 100 kg/m³, having an overall rectangular polygonal upper surface (4), an identically overall rectangular polygonal lower surface parallel to the upper surface and separated from the upper surface in a thickness direction of the insulating block, and a plurality of lateral surfaces (3) extending between the upper surface and the lower surface perpendicularly to the upper and lower surfaces, wherein the lateral surfaces (3) define a rectangular geometrical envelope ofthe upper and lower surfaces, the polymer foam pad having a plurality of corner surfaces (2) which extend between two adjacent lateral surfaces (3) of the pad and in the thickness direction of the insulating block, and which are short in comparison with the adjacent lateral surfaces (3) of the pad, the corner surfaces (2) being formed by cutouts cutting the rectangular geometrical envelope of the upper and lower surfaces in the thickness direction of the insulating block at a plurality of corners of the rectangular geometrical envelope ofthe upper and lower surfaces, and a plurality of corner posts (5, 105, 205, 405, 505, 605) fixed to the polymer foam pad in the cutouts and extending over the entire thickness of the insulating block between the upper and lower surfaces, each corner post having an inner lateral

2014252951 25 Sep 2018 surface (6, 106, 406, 506, 606) fully covering a corner surface (2) of the polymer foam pad, wherein the corner posts (5, 105, 205) are made of a material which has a thermal expansion coefficient of between 75% and 125% of the thermal expansion coefficient of the polymer foam constituting the pad, and which has an elastic limit in compression of more than 1.5 MPa, , at a temperature of 23°C, the inner lateral surface of the corner post being adhesively bonded to the corner surface, and wherein the material of the corner posts (5, 105, 205) is selected from a group consisting of a polymer foam with a density greater than or equal to 170 kg/m³ and a polymer resin, wherein the inner lateral surface (406, 506, 606) comprises a hook element (420, 520, 620) projecting transversely from the corner post (405, 505, 605) toward the polymer foam pad, the hook element comprising a cross section in a plane parallel to the thickness of the insulating block which has a small surface area in comparison with a total surface area of the inner lateral surface.

3. The insulating block as claimed in claim 2 wherein the hook element (620) extends over the entire length of the corner post and projects over a small portion of the periphery of the corner post.

4. The insulating block as claimed in claim 2, wherein the hook element extends over a small portion of the length of the corner post.

5. The insulating block as claimed in any one of claims 2 to 4, wherein the inner lateral surface comprises a plurality of juxtaposed hook elements (420, 520, 620).

6. The insulating block as claimed in claim 5, wherein two successive hook elements (420, 520) of the plurality of juxtaposed hook elements are spaced apart (422, 522) on the inner lateral surface.

7. The insulating block as claimed in any preceding claim, wherein the corner posts (5, 105, 205) are made of a material which has an elastic limit in compression of more than 3MPa, , at a temperature of 23°C,

2014252951 25 Sep 2018

8. The insulating block as claimed in any preceding claim, wherein the polymer foam constituting the pad (1) is a closed-cell polyurethane foam with a density greater than or equal to 130 kg/m³.

9. The insulating block as claimed in any preceding claim, wherein the material of the corner posts (5, 105, 205) is a polymer foam with a density greater than or equal to 170 kg/m³.

10. The insulating block as claimed in one of claims 1 to 7, wherein the material of the comer posts (5, 105, 205) comprises a polymer resin.

11. The insulating block as claimed in any preceding claim, furthermore comprising a plywood cover panel (13) fixed on the upper surface of the polymer foam pad, the cover panel covering in the corners an upper surface of the comer posts, the cover panel having a contour aligned with the lateral surfaces of the polymer foam pad and with an outer lateral surface of the corner posts fixed to the pad.

12. The insulating block as claimed in claim 11, wherein the cover panel has a plurality of recesses (15) arranged above each of the corner posts.

13. The insulating block as claimed in one of claims 1 to 10, furthermore comprising a plywood bottom panel (14) fixed under the lower surface of the polymer foam pad, the bottom panel covering in the corners a lower surface of the corner posts, the bottom panel having a contour aligned with the lateral surfaces of the polymer foam pad and with an outer lateral surface of the corner posts fixed to the pad.

14. A leaktight and thermally insulating tank arranged in a carrying structure in order to contain a cold fluid, wherein the wall of the tank successively comprises in a thickness direction a primary leaktight membrane (24) intended to be in contact with the fluid, a primary insulating barrier (23), a secondary leaktight membrane (22), and a secondary insulating barrier (21) arranged between the secondary leaktight membrane and the carrying structure, wherein the primary insulating barrier comprises a set of insulating blocks (23) as claimed in any preceding claim juxtaposed in order to form a plane support surface for the primary leaktight membrane, the upper surface of the insulating blocks facing toward an interior of the tank,

2014252951 25 Sep 2018 the wall of the tank furthermore comprising anchoring members (28, 37, 38, 39) for retaining the insulating blocks (23) on the secondary leaktight membrane, an anchoring member in each case comprising a bearing element (38) engaging on the upper surface (4) of the insulating block in line with a corner post (5, 105, 205) and a connecting element (28) arranged between the juxtaposed insulating blocks, attached to the bearing element and extending from the bearing element in the thickness direction of the insulating blocks (23) in the direction of the carrying structure (20), the connecting element being attached to the secondary insulating barrier (21, 20) or to the carrying structure in order to press the insulating blocks (23) onto the secondary leaktight membrane (22).

15. A ship (70) for transporting a cold liquid product, the ship comprising a double hull (72) and a tank (71) as claimed in claim 14 arranged in the double hull.

16. A method for loading or unloading a ship (70) as claimed in claim 15, wherein a cold liquid product is conveyed through insulated pipelines (73, 79, 76, 81) from or to a floating or onshore storage installation (77) to or from the tank of the ship (71).

17. A transfer system for a cold liquid product, the system comprising a ship (70) as claimed in claim 15, insulated pipelines (73, 79, 76, 81) arranged in order to connect the tank (71) installed in the hull of the ship to a floating or onshore storage installation (77), and a pump for driving a flow of cold liquid product through the insulated pipelines from or to the floating or onshore storage installation to or from the tank of the ship.

WO 2014/167206

PCT/FR2014/050723

1/6

FIG. 3 FIG.4

WO 2014/167206

PCT/FR2014/050723

2/6

FI6.6

WO 2014/167206

PCT/FR2014/050723

3/6

FI6.7

Wo ^20l4/l67206

4/6 ^PCT^II2I>,^_SO723

WO 2014/167206

PCT/FR2014/050723

5/6

WO 2014/167206

PCT/FR2014/050723

6/6

FIG. 13 *