Method for producing a thermal insulation barrier for a tank

Abstract

The invention relates to a method for producing a thermal insulation barrier (5) for a wall (1) of a sealed and thermally insulating tank fixed to a supporting structure (2), the method comprising the following steps: - anchoring a plurality of insulating plates (11) by means of at least one anchoring device (12), the plurality of insulating plates (11) having a receiving portion (18) in which the anchoring device (12) is accommodated; - inserting an insulating plug (25) inside the receiving portion (18) and pushing the insulating plug (25) in the direction of the supporting structure (2) until the insulating plug (25) bears against a bearing surface in the direction of the supporting structure (2); - trimming the insulating plug (25) so that the inner end of the insulating plug (25) is flush with the inner surface of the plurality of insulating plates (11).

Description

Technical Field

[0001] The present invention relates to the field of sealed and thermally insulated tanks for storing and / or transporting liquefied gases, such as tanks for transporting liquefied petroleum gas (also called LPG) having a temperature of, for example, between -50°C and 0°C, or tanks for transporting liquefied natural gas (LNG) at approximately -162°C and atmospheric pressure.

[0002] These tanks can be installed on land or on floating structures. In the case of floating structures, the tanks can be used to transport liquefied gas, or contain liquefied gas to be used as a propulsion fuel for the floating structure. Background Art

[0003] Document WO19092384 discloses a method for manufacturing a thermal insulation barrier for the wall of a sealed and thermally insulated tank. The wall of the tank has a multilayer structure, which has, in the thickness direction, from the outside to the inside of the tank, in sequence: a secondary thermal insulation barrier having an insulating plate held on a supporting structure; a secondary sealing film, which rests against the secondary thermal insulation barrier; a primary thermal insulation barrier having an insulating plate resting against the secondary sealing film; and a primary sealing film, which rests against the primary thermal insulation barrier and is intended to be in contact with the liquefied natural gas contained in the tank. Each insulating plate of the primary thermal insulation barrier has cutouts along its edges and at its corners. These cutouts define recesses, which form receiving portions in which anchoring devices are received, which fix the insulating plates of the primary thermal insulation barrier on the insulating plates of the secondary thermal insulation barrier. An insulating plug having an insulating polymer foam layer is received in a receiving portion formed in the primary thermal insulation barrier to ensure the continuity of thermal insulation. To do this, said document provides for inserting each insulating plug inside the corresponding receiving portion and pushing it in the direction of the supporting structure until it is irreversibly destroyed where it bears against a supporting member received inside the receiving portion. Each insulating plug is pushed until the inner end of the insulating plug reaches a predetermined position inside the receiving portion.

[0004] This can prevent the insulating plug from locally causing a difference in level which affects the flatness of the supporting surface of the primary sealing membrane even when the insulating plug has a large dimensional manufacturing tolerance.

[0005] However, this method is not entirely satisfactory. In particular, pushing the insulating plugs until they are irreversibly deformed requires considerable force on the part of the operator, which prolongs the manufacturing time of the thermal insulation barrier and impairs the working conditions of the operator, especially when the polymer foam of the insulating plugs has a high density. Summary of the invention

[0006] The idea underlying the invention is to provide a method for manufacturing a thermal insulation barrier, intended to define an inner supporting surface of a sealing membrane and having a receiving portion and an insulating plug received in said receiving portion, the method being easy to implement and limiting the presence of differences in level in the inner supporting surface of the sealing membrane in line with the receiving portion.

[0007] According to one embodiment, the present invention provides a method for manufacturing a thermal insulation barrier for securing to a supporting structure a wall of a sealed and thermally insulating tank, the method comprising the following steps:

[0008] - directly or indirectly anchoring to the support structure a plurality of insulating panels defining an inner surface intended to support the sealing membrane and having receiving portions opened out at the inner surface and in which the anchoring devices are received, by means of at least one anchoring device;

[0009] - providing an insulating plug intended to ensure continuity of thermal insulation at the receiving portion, said insulating plug having an inner end and an outer end and having a dimension d1 between the inner and outer ends, said insulating plug having an insulating polymer foam layer and an inner rigid plate fixed to the insulating polymer foam layer and forming the inner end of the insulating plug;

[0010] - inserting the insulating plug inside the receiving portion and pushing the insulating plug in the direction of the supporting structure until the outer end of the insulating plug bears against a bearing surface in the direction of the supporting structure, the bearing surface being spaced apart from the inner surface of the plurality of insulating plates by a distance d2 that is smaller than d1;

[0011] - Trimming the inner rigid plate of the insulating plug so that the inner end of the insulating plug is flush with the inner surface of the plurality of insulating plates.

[0012] This method is therefore particularly simple since it does not require the application of a large pushing force in order to deform the insulating plug and allows the dimensional tolerances of the plug to be increased since they are not critical in the proposed method. Furthermore, this method prevents the insulating plug from locally causing differences in level at the supporting surface of the sealing membrane.

[0013] Depending on the embodiment, this method may have one or more of the following features.

[0014] According to one embodiment, the inner rigid plate is made of plywood.

[0015] According to a variant embodiment, the inner rigid plate is glued to the insulating polymer foam layer, for example by means of polyurethane glue or epoxy glue.

[0016] According to another variant embodiment, the inner rigid plate is stapled to the insulating polymer foam layer.

[0017] According to one embodiment, the anchoring device received inside the receiving portion has a pin, which is directly or indirectly fixed to the support structure. When anchoring a plurality of insulating panels, a retaining member is mounted on the pin so that the retaining member cooperates with the retaining area of ​​at least one insulating panel to retain the insulating panel towards the support structure, and a nut is screwed onto the pin to fix the retaining member on the pin.

[0018] According to one embodiment, the retaining member forms a bearing surface against which the outer end of the insulating plug is urged.

[0019] According to one embodiment, the insulating plug has an outer rigid plate with an outer face and an inner face, the outer face forming the outer end of the insulating plug, the inner face being in contact with the insulating polymer foam layer of the insulating plug, the outer rigid plate having a groove made in the outer face of the outer rigid plate and in which the nut of the anchoring device is received. This allows the insulating polymer foam layer to better withstand the compressive forces.

[0020] According to one embodiment, the inner face of the outer rigid plate at least partially covers the groove.

[0021] According to one embodiment, the outer rigid plate has a hole which opens into the groove and in which one end of the pin is received, the hole having a diameter which is smaller than the diameter of the groove.

[0022] According to one embodiment, the hole is a blind hole.

[0023] According to one embodiment, the outer rigid plate is secured to the insulating polymer foam layer.

[0024] According to a variant embodiment, the outer rigid plate is glued to the insulating polymer foam layer, for example by means of polyurethane glue or epoxy glue.

[0025] According to another variant embodiment, the outer rigid plate is bound to the insulating polymer foam layer.

[0026] According to another embodiment, the outer rigid plate is free relative to the insulating polymer foam layer, and the insertion of the insulating plug inside the receiving portion comprises a stage of inserting the outer rigid plate and then a stage of inserting the insulating polymer foam layer into the receiving portion.

[0027] According to another embodiment, the outer rigid plate is selected from a plurality of outer rigid plates having different thicknesses to limit the thickness of the inner rigid plate to be trimmed to Δ= d1 - d2 .

[0028] According to one embodiment, the insulating polymer foam layer has a density between 100 and 260 kg / m 3 between.

[0029] According to one embodiment, the outer rigid panel is stapled to one of the insulating panels.

[0030] According to another aspect, the present invention also provides a thermal insulation barrier for sealing and thermally insulating the wall of a tank fixed to a supporting structure, the thermal insulation barrier having:

[0031] - a plurality of insulating panels, directly or indirectly anchored to the supporting structure by means of at least one anchoring device, the plurality of insulating panels defining an inner surface intended to support the sealing membrane and having receiving portions opened out at the inner surface and in which the anchoring device is received;

[0032] - an anchoring device received inside the receiving portion has a pin, which is directly or indirectly fixed to the supporting structure, a retaining member mounted on the pin so that it cooperates with the retaining zone of at least one insulating plate, and a nut screwed onto the pin to fix the retaining member on the pin;

[0033] - an insulating plug, which is received inside the receiving part to ensure the continuity of thermal insulation at the receiving part, the insulating plug having an insulating polymer foam layer, an inner rigid plate and an outer rigid plate, the inner rigid plate being fixed to the insulating polymer foam layer and forming the inner end of the insulating plug, the outer rigid plate having an inner face and an outer face, the inner face being in contact with the insulating polymer foam layer of the insulating plug, the outer face forming the outer end of the insulating plug and being supported against the retaining member in the direction of the supporting structure, the outer rigid plate having a groove, the groove being made in the outer face of the outer rigid plate, and the nut of the anchoring device being received in the groove, the inner face of the outer rigid plate at least partially covering the groove.

[0034] Thus, with this arrangement, the support area of ​​the insulating polymer foam layer is larger, that is to say, the area through which the compressive forces under the dynamic and static pressure exerted by the liquid contained in the tank pass is larger. This enables the insulating polymer foam layer to better withstand the compressive forces without having a higher density.

[0035] According to one embodiment, the invention relates to a tank wall having a thermal insulation barrier as described above and a sealing membrane resting against the thermal insulation barrier and intended to be in contact with the liquid stored in the tank.

[0036] According to one embodiment, the invention relates to a sealed and thermally insulated can having the wall described above.

[0037] A tank according to one of the embodiments described above may form part of an onshore storage facility (e.g. for storing LNG) or may be installed in a floating structure onshore or offshore, in particular in an ethane or methane carrier, a floating storage and regasification unit (FSRU), a floating production storage and offloading (FPSO) unit, etc. In the case of a floating structure, the tank may be used to contain liquefied natural gas as a propulsion fuel for the floating structure.

[0038] According to one embodiment, the thermal insulation barrier described above is a primary thermal insulation barrier, and the tank wall further has a secondary thermal insulation barrier and a secondary sealing film, wherein the secondary sealing film is arranged between the primary thermal insulation barrier and the secondary thermal insulation barrier.

[0039] According to one embodiment, a ship for transporting a fluid has a hull, such as a double hull, and a tank as described above, which is arranged in the hull.

[0040] According to one embodiment, the invention also provides a method of loading or unloading such a vessel, wherein fluid is conducted from a floating storage facility or an onshore storage facility to a tank of the vessel, or from a tank of the vessel to a floating storage facility or an onshore storage facility, via an insulated pipeline.

[0041] According to one embodiment, the present invention also provides a system for transferring fluid, the system having the ship described above, an insulating pipe and a pump, the insulating pipe being arranged to connect a tank installed in the hull of the ship to a floating storage facility or an onshore storage facility, the pump being used to drive the fluid from the floating storage facility or the onshore storage facility to the tank of the ship, or from the tank of the ship to the floating storage facility or the onshore storage facility through the insulating pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The invention will be better understood, and further objects, details, features and advantages thereof will become more apparent from the following description of a number of specific embodiments thereof, which are given by way of non-limiting illustration only with reference to the accompanying drawings.

[0043] [ Figure 1 ] Figure 1 is a cutaway perspective view of the wall of a sealed and thermally insulated tank.

[0044] [ Figure 2 ] Figure 2 is a cross-sectional view of a thermal insulation barrier according to a first embodiment, the cross-section being through an insulation plug.

[0045] [ Figure 3 ] Figure 3 is a cross-sectional view of a thermal insulation barrier according to a second embodiment, the cross-section being through an insulation plug.

[0046] [ Figure 4 ] Figure 4 is a schematic cross-sectional view of a ship having a tank for storing liquefied natural gas and a dock for loading / unloading from the tank.

[0047] [ Figure 5 ] Figure 5 is a cutaway perspective view of a wall of a sealed and thermally insulated can according to another embodiment. Specific embodiments

[0048] By convention, the terms "external" and "inner" are used to define the relative position of one element with respect to another element, with reference to the outside and the inside of the can.

[0049] Figure 1 The multilayer structure of the wall 1 of a sealed and thermally insulated tank for storing fluids, such as liquefied natural gas (LNG), is shown. Each wall 1 of the tank has, in order from the outside to the inside of the tank in the thickness direction: a secondary thermal insulation barrier 3, which is held on a support structure 2; a secondary sealing film 4, which rests against the secondary thermal insulation barrier 3; a primary thermal insulation barrier 5, which rests against the secondary sealing film 4; and a primary sealing film 6, which is intended to be in contact with the liquefied natural gas contained in the tank.

[0050] In particular, the support structure 2 may comprise a self-supporting metal sheet, or more generally, any type of rigid bulkhead having suitable mechanical properties. In particular, the support structure 2 may be formed by the hull or double hull of a ship. The support structure 2 has a plurality of walls which define the general shape of the tank, which is generally a polyhedral shape.

[0051] The secondary thermal insulation barrier 3 has a plurality of secondary insulation panels 7, which are anchored to the support structure 2 by means of resin strips and pins welded to the support structure 2. The secondary insulation panels 7 are substantially in the shape of a rectangular parallelogram and are juxtaposed in parallel rows separated from each other by gaps, which ensure a functional mounting gap. The gaps are filled with an insulating filler, such as glass wool, rock wool or an open-cell flexible synthetic foam. The secondary insulation panels 7 each have a polymer foam layer 8, which is sandwiched between an inner panel 9 and an outer panel 10. The inner panel 9 and the outer panel 10 are, for example, plywood sheets bonded to the polymer foam layer 8. In particular, the polymer foam 8 can be a polyurethane-based foam, which is optionally reinforced with fibers, such as glass fibers.

[0052] In the embodiment shown, the secondary sealing membrane 4 comprises a continuous layer of metal strips with raised edges. The strips are welded by their raised edges to parallel welding supports which are fixed in grooves formed in the inner plate 9 of the secondary insulating plate 7. For example, the strips consist of (i.e., an alloy of iron and nickel) and has a coefficient of expansion of typically 1.2×10 -6 and 2×10 -6 K -1 between.

[0053] According to another embodiment (not shown), the secondary sealing membrane 4 has a plurality of corrugated metal plates, each of which has a substantially rectangular shape and is overlap-welded to each other. Also, the corrugated metal plates are welded to a metal plate that is fixed to the inner plate 9 of the secondary insulating plate 7. For example, the corrugations protrude toward the outside of the tank body and are received in grooves formed in the inner plate 9 of the secondary insulating plate 7.

[0054] In addition, the primary thermal insulation barrier 5 has a plurality of primary insulation plates 11 in a substantially rectangular parallelogram shape. Here, the primary insulation plates 11 are offset relative to the secondary insulation plates 7 of the secondary thermal insulation barrier 3, so that each primary insulation plate 11 is arranged in a staggered manner on four secondary insulation plates 7. The primary insulation plates 11 are fixed to the secondary insulation plates 7 by means of anchoring means 12, which will be described below.

[0055] In the embodiment shown, each primary insulation panel 11 has a polymer foam layer 13 sandwiched between two rigid panels, an outer panel 15 and an inner panel 14. For example, the outer panel 15 and the inner panel 14 are made of plywood. The polymer foam layer 13 is, for example, polyurethane foam, which is optionally reinforced with fibers, such as glass fibers.

[0056] The primary sealing membrane 6 is obtained by assembling a plurality of corrugated metal plates. The corrugated metal plates are respectively in a substantially rectangular shape. The corrugations protrude toward the interior of the tank body. The corrugated metal plates of the primary sealing membrane 6 are arranged in an offset manner relative to the primary insulating plates 11, so that each of the corrugated metal plates extends together on four adjacent primary insulating plates 11. The corrugated metal plates are overlap-welded together and are also welded along their edges to a metal disc that is fixed to the primary insulating plates 11 and more specifically to the inner plates 14 thereof. The inner plates 14 of the primary insulating plates 11 define the inner support surface of the primary sealing membrane 6.

[0057] like Figure 1 As shown in FIG. 1 , each primary insulating panel 11 has a recess 16 at each corner thereof. Each recess 16 passes through the inner panel 14 and extends over the entire thickness of the polymer foam layer 13.

[0058] Therefore, if Figure 2 As shown in FIG. 1 , at each recess 16, the outer panel 15 protrudes beyond the polymer foam layer 13 and beyond the inner panel 14 to form a bearing area 17 cooperating with the anchoring device 12. Each recess 16 formed in the corner of one primary insulating panel 11 is arranged facing the recesses 16 formed in the corners of three adjacent primary insulating panels 11, so that the four recesses 16 together define a receiving portion 18 of the primary thermal insulation barrier 5. Therefore, a single anchoring device 12 arranged in the receiving portion 18 can cooperate with four bearing areas 17 belonging to four adjacent primary insulating panels 11, respectively.

[0059] In the embodiment shown, a clamping plate 19, for example made of plywood, is fastened to the support area 17 of each primary insulating plate 11 in order to reinforce it.

[0060] In the illustrated embodiment, each receiving portion 18 is formed by a plurality of recessed portions 16 formed at the corners of the primary insulating board 11. However, in other embodiments not shown, each receiving portion 18 is formed neither at the edge of the primary insulating board 11 nor at one corner thereof, but is formed by the polymer foam layer 13 of a single primary insulating board 11.

[0061] In the embodiment shown, each anchoring device 12 has a pin 20 protruding from a metal plate (not shown) fixed to the inner plate 9 of one of the secondary insulating plates 7. The pins 20 pass through holes formed in the secondary sealing membrane 4, respectively. In addition, the secondary sealing membrane 4 is welded to the metal plate around the hole in a sealing manner to ensure the sealing of the passage of the pin 20 through the secondary sealing membrane 4.

[0062] like Figure 2 As shown in FIG. 1 , each anchoring device 12 has a retaining member 21, which is fixed on each pin 20 and, in this case, is supported against the support area 17 of each of the four adjacent primary insulating plates 11 via the clamping plate 19. In addition, a fixing member, such as a nut 22, cooperates with the thread of the pin 20 and is supported against the inner surface of the retaining member 21, so that the retaining member 21 is fixed on the pin 20, thereby applying a retaining force to the support area 17. The nut 22 is, for example, a slotted nut and has the advantage of not being loosened during operation.

[0063] exist Figure 2 In the embodiment of FIG. 2 , the retaining member 21 is an annular disk having an orifice passing through the pin 20 .

[0064] Furthermore, in an embodiment not shown, one or more elastic washers, for example Belleville washers, are threaded onto the pin 20 between the nut 22 and the retaining member 21 , which makes it possible to elastically anchor the primary insulating plate 11 to the secondary insulating plate 7 .

[0065] The primary thermal insulation barrier 5 has an insulating plug 25 which is intended to be inserted into the receiving portion 18 to ensure the continuity of the thermal insulation. The insulating plug 25 has an insulating polymer foam layer 23. The insulating polymer foam layer 23 is, for example, polyurethane foam, which is optionally reinforced with fibers such as glass fibers. The insulating polymer foam layer 23 has a density between 100 and 260 kg / m 3 Between, and advantageously between 110 and 150 kg / m 3 Between, for example about 130kg / m 3 .

[0066] Furthermore, the insulating plug 25 has an inner rigid plate 24, for example made of plywood, which forms the inner end of the insulating plug 25. The inner rigid plate 24 is advantageously bonded to the insulating polymer foam layer 23, for example by means of polyurethane glue or epoxy glue. According to another variant embodiment, the inner rigid plate 24 is stapled to the insulating polymer foam layer 23. In this case, the staples are advantageously placed at a distance from the inner face of the inner rigid plate 24, for example arranged in a cavity formed in the inner face of the inner rigid plate 24, so as not to impair the subsequent grinding operation described below.

[0067] The insulating plug 25 has an outer end which bears against a bearing surface received in the receiving portion 18 in the direction of the supporting structure 2. In the embodiment shown, the bearing surface is formed by the retaining member 21. The bearing surface is placed at a distance d2 from the inner bearing surface of the primary sealing membrane 6.

[0068] exist Figure 2 In the embodiment shown, the insulating plug 25 has a groove 26 which is opened at the outer end of the insulating plug 25 and in which the nut 22 of the anchoring device 12 is formed. The insulating plug 25 also has a blind hole 27 which opens into the groove 26 and in which the end of the pin 20 is received. In the initial state, the insulating plug 25 has a dimension d1 between the inner and outer ends of the insulating plug 25, which is measured in the thickness direction of the wall 1. The dimension d1 is smaller than d2.

[0069] During production of the primary thermal insulation barrier 5 , the insulating plug 25 is inserted inside the receiving portion 18 and then pushed in the direction of the supporting structure 2 until the outer end of the insulating plug 25 bears against a bearing surface, that is to say against the retaining member 21 .

[0070] Subsequently, the inner rigid plate 24 is trimmed to a thickness of e=d1-d2, so that the inner surface of the inner rigid plate 24 thus trimmed is flush with the inner support surface of the primary sealing membrane 6. This operation thus allows the inner surface of the inner rigid plate 24 of the insulating plug 25 to be flush with the inner surface of the primary insulating plate 11. This trimming operation is carried out, for example, with the aid of a plane. A plane is usually equipped with one or more handles, a base plate intended to cooperate with the surface to be planed (in this case, the inner surface of the inner rigid plate 24), and a tool flush with the base plate, the tool being used to process the surface to be planed. According to one embodiment, the tool is a drum equipped with a blade or a milling cutter, and is driven to rotate by a motor.

[0071] Finally, in order to keep the insulating plug 25 in place, the inner rigid plate 24 is fixed to the primary thermal insulation barrier 5. To this end, the inner rigid plate 24 is fixed to one of the four primary insulating plates 11 adjacent to the receiving portion 18, for example by means of one or more staples, which are arranged in a bridging manner between the inner rigid plate and one of the primary insulating plates 11.

[0072] Such a method is advantageous because it can prevent the insulating plug 25 from locally causing a difference in level that affects the flatness of the supporting surface of the primary sealing membrane 6 .

[0073] Figure 3 An insulating plug 25 according to another embodiment is shown. As in the previous embodiment, the insulating plug 25 has an inner rigid plate 24 which is trimmed so that its inner face is flush with the inner support surface of the primary sealing membrane 6.

[0074] However, Figure 3 The insulating plug 25 in the embodiment of Figure 2 Unlike the related embodiment, it also includes an outer rigid plate 28, for example made of plywood. The outer rigid plate 28 has an outer face which forms the outer end of the insulating plug 25 and which is therefore intended to bear against a bearing surface in the direction of the support structure 2, that is to say against the retaining member 21 in the embodiment shown. The outer rigid plate 28 has an inner face in contact with the insulating polymer foam layer 23. According to one embodiment, the outer rigid plate 28 is bonded to the insulating polymer foam layer, for example by means of polyurethane glue or epoxy glue. As an alternative, the outer rigid plate 28 is stapled to the insulating polymer foam layer 23.

[0075] According to another embodiment, the insulating plug 25 is made in two parts, which are free relative to each other and respectively have an outer rigid plate 28 on the one hand and an insulating polymer foam layer 23 and an inner rigid plate 24 on the other hand. In this case, the insulating plug 25 is inserted inside the receiving part in two stages. In a first stage, the outer rigid plate 28 is inserted into the receiving part 18 and is pushed in the direction of the supporting structure 2 until it bears against the retaining member 21. In a second stage, the insulating polymer foam layer 23 and the inner rigid plate 24 are inserted into the receiving part 18 and then pushed in the direction of the supporting structure 2 until the insulating polymer foam layer 23 bears against the outer rigid plate 28.

[0076] Furthermore, the outer rigid plate 28 has a groove 29 which is made in the outer face of the outer rigid plate 28 and in which the nut 22 of the anchoring device 12 is received. In the embodiment shown, the outer rigid plate 28 also has a hole 30 which has a diameter smaller than the diameter of the groove 29 and in which the end of the pin 20 is received. The hole 30 can be a through hole and thus passes through the inner face of the outer rigid plate 29, or it can be a blind hole, that is to say it does not pass through the inner face of the outer rigid plate 28. In any case, the inner face of the outer rigid plate 28 at least partially covers the groove 29.

[0077] Therefore, by this arrangement, the support area of ​​the insulating polymer foam layer 23, that is, the area of ​​the insulating polymer foam layer 2 through which the compressive force under the dynamic pressure and static pressure exerted by the liquid contained in the tank body passes, is larger than Figure 2 This can prevent the insulating polymer foam layer 23 from being crushed, or cause crushing to occur to a lesser extent, and enable the insulating polymer foam layer 22 to better withstand compressive forces without having a greater density.

[0078] according to Figure 3 In a variant of the embodiment, the operator has a set of a plurality of outer rigid plates 28 with different thicknesses and selects an outer rigid plate 28 whose thickness makes it possible to limit the thickness Δ= d1 - d2 of the inner rigid plate 24 to be ground.

[0079] When the outer rigidizing plate 28 has been selected, according to one embodiment, it is then secured to the insulating polymer foam layer 22 by gluing, by stapling or by means of one or more screws.

[0080] Figure 5 The wall of the tank according to another embodiment is shown. Figure 1 The embodiment described differs in that each primary insulating plate 11 is placed aligned with one secondary insulating plate 7 , being aligned with the secondary insulating plates 7 in the thickness direction of the wall 1 .

[0081] Therefore, the anchoring devices are preferably placed at the four corners of the secondary insulation panels 7 and the primary insulation panels 11. Therefore, each stack of secondary insulation panels 7 and primary insulation panels 11 is anchored to the support structure 2 by means of four anchoring devices. And, each anchoring device cooperates with the corners of four adjacent secondary insulation panels 7 and the corners of four adjacent primary insulation panels 11.

[0082] Furthermore, in this embodiment, the primary sealing film 6 has a continuous layer of metal strips with raised edges. Figure 1 Like the secondary sealing membrane 4 of the embodiment of the present invention, the metal strips are welded by their raised edges to parallel welding supports, which are fixed in grooves formed on the inner plate of the primary insulating plate 11.

[0083] Reference Figure 4 , a cross-sectional view of a methane ship 70 shows a sealed and insulated tank 71 having a generally prismatic shape and installed in a double hull 72 of the ship. The wall of the tank 71 has: a primary membrane intended to be in contact with the LNG contained in the tank; a secondary membrane arranged between the primary membrane and the double hull 72 of the ship; and two thermal insulation barriers arranged between the primary membrane and the secondary membrane and between the secondary membrane and the double hull 72, respectively.

[0084] In a manner known per se, a loading / unloading pipeline 73 arranged on the upper deck of the vessel can be connected to a marine terminal or a port terminal by means of appropriate connectors in order to transfer a shipload of LNG from or to the tank 71 .

[0085] Figure 4 Also shown is an example of a marine terminal having a loading and unloading station 75, an underwater pipeline 76 and an onshore facility 77. The loading and unloading station 75 is a fixed offshore facility having a mobile arm 74 and a tower 78 supporting the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible hoses 79, which can be connected to the loading / unloading pipeline 73. The orientable mobile arm 74 can accommodate methane ships of various sizes. A connecting pipeline (not shown) extends inside the tower 78. The loading and unloading station 75 enables the methane ship 70 to be loaded or unloaded from the onshore facility 77 to the onshore facility 77. The onshore facility 77 has a liquefied gas storage tank 80 and a connecting pipeline 81, which is connected to the loading or unloading station 75 through an underwater pipeline 76. The underwater pipeline 76 can transfer liquefied gas over a long distance (e.g., 5 kilometers) between the loading or unloading station 75 and the onshore facility 77, which enables the methane ship 70 to maintain a long distance from the shore during the loading and unloading operation.

[0086] In order to generate the pressure required for transferring the liquefied gas, pumps carried on board the ship 70 and / or pumps equipped at the land facility 77 and / or pumps equipped at the loading and unloading station 75 may be used.

[0087] Although the present invention has been described in conjunction with a number of specific embodiments, it is obvious that it is by no means limited thereto and that it comprises all technical equivalents of the means described and combinations thereof, if these are within the scope of the present invention.

[0088] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0089] Although the invention has been described in connection with a number of specific embodiments, it is obvious that it is by no means restricted thereto and that it comprises all technical equivalents of the means described and combinations thereof, if these are within the scope of the invention as defined by the claims.

[0090] Use of the verb "have", "comprise" or "include" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim.

[0091] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims

1. A method for producing a thermal insulation barrier (5) for use in sealing and thermally insulating a tank wall (1) fixed to a supporting structure (2), said method comprising the following steps: - directly or indirectly anchoring a plurality of insulating panels (11) to a supporting structure (2) by means of at least one anchoring device (12), said plurality of insulating panels (11) defining an inner surface intended to support a sealing membrane (6) and comprising a receiving portion (18) having an inner end open at the inner surface, wherein said anchoring device (12) is received in said receiving portion (18); - providing an insulating plug (25) intended to ensure continuity of thermal insulation at the receiving portion (18), said insulating plug (25) having an inner end and an outer end and having a dimension d1 between the inner and outer ends, said insulating plug (25) having an insulating polymer foam layer (23) and an inner rigid plate (24) fixed to the insulating polymer foam layer (23) and forming the inner end of the insulating plug (25); - inserting the insulating plug (25) inside the receiving portion (18) and pushing the insulating plug (25) in the direction of the supporting structure (2) until the outer end of the insulating plug (25) bears against a bearing surface in the direction of the supporting structure (2), the bearing surface being spaced apart from the inner surface of the plurality of insulating plates (11) by a distance d2, d2 being less than d1; - Trimming the inner rigid plate (24) of the insulating plug (25) so that the inner end of the insulating plug (25) is flush with the inner surface of the plurality of insulating plates (11).

2. The method according to claim 1, wherein the inner rigid plate (24) is made of plywood.

3. A method according to claim 1 or 2, wherein the inner rigid panel (24) is bonded or stapled to the insulating polymer foam layer (23).

4. The method according to claim 1 or 2, wherein the anchoring device (12) received inside the receiving portion (18) has a pin (20) which is fixed directly or indirectly to the supporting structure (2), wherein When anchoring a plurality of insulating panels (11), a retaining member (21) is mounted on a pin (20) such that the retaining member cooperates with a retaining region of at least one of the plurality of insulating panels (11) to retain the insulating panel toward a support structure (2), and wherein a nut (22) is screwed onto the pin (20) to secure the retaining member (21) to the pin (20).

5. Method according to claim 4, wherein the retaining member (21) forms a bearing surface against which the outer end of the insulating plug (25) is urged.

6. A method according to claim 4, wherein the insulating plug (25) has an outer rigid plate (28), the outer rigid plate (28) has an outer face and an inner face, the outer face forms the outer end of the insulating plug (25), the inner face contacts the insulating polymer foam layer (23) of the insulating plug (25), the outer rigid plate (28) has a groove (29), the groove (29) is made in the outer face of the outer rigid plate (28), and the nut (22) of the anchoring device (12) is received in the groove (29).

7. A method according to claim 6, wherein the inner face of the outer rigid plate (28) at least partially covers the groove (29).

8. A method according to claim 6, wherein the outer rigid plate (28) has a hole (30) which opens into the groove (29) and in which one end of the pin (20) is received, The hole (30) has a diameter that is smaller than the diameter of the groove (29).

9. The method according to claim 8, wherein the hole (30) is a blind hole.

10. The method of claim 6, wherein an outer rigid plate (28) is secured to the insulating polymer foam layer (23).

11. The method according to claim 6, wherein the outer rigid plate (28) is free relative to the insulating polymer foam layer (23), and the insertion of the insulating plug (25) into the interior of the receiving portion (18) comprises: The outer rigid plate (28) is inserted into the stage of the receiving portion (18), and then the insulating polymer foam layer (23) is inserted into the stage of the receiving portion (18).

12. The method according to claim 11, wherein the outer rigid plate (28) is selected from a plurality of outer rigid plates having different thicknesses to limit the thickness Δ=d1-d2 of the inner rigid plate (24) to be trimmed.

13. The method according to claim 1 or 2, wherein the insulating polymer foam layer (23) has a density between 100 and 260 kg / m 3 between.

14. The method according to claim 1 or 2, wherein an inner rigid panel (24) is stapled to one of the plurality of insulating panels (11).

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