Method for producing the wall of a sealed thermally insulating tank

Abstract

The invention relates to a method for manufacturing a wall of a sealed thermally insulated tank, the wall comprising at least one thermally insulating barrier and a sealing membrane bearing against the thermally insulating barrier, the method comprising: manufacturing a plurality of wall elements, the manufacturing of each wall element comprising: providing a sealing plate; placing an expandable insulating foam solution against the sealing plate; and expanding the expandable insulating foam solution (40) against the sealing plate (33); anchoring the manufactured wall element (32) to a supporting structure; the expanded insulating foam layer (34) of the wall element (32) forming at least a part of the thermally insulating barrier; and tightly assembling the sealing plates (33) of the wall elements (32) such that the sealing plates (33) form at least a part of the sealing membrane.

Description

Technical Field

[0001] The present invention relates to the field of sealed thermally insulated tanks with membranes for storing and / or transporting fluids. In particular, the present invention relates to the field of sealed thermally insulated tanks for storing and / or transporting liquefied gases at low temperatures, such as tanks for transporting, for example, liquefied petroleum gas (also called LPG) at a temperature between -50°C and 0°C, or tanks for transporting liquefied natural gas (LNG) at about -162°C at atmospheric pressure. These tanks can be installed on shore or on a floating structure. In the case of a floating structure, the tank can be used for transporting liquefied gas or for receiving liquefied gas used as fuel for propelling the floating structure.

[0002] The invention more particularly relates to a method for manufacturing the wall of such a sealed thermally insulating tank. Technical Background

[0003] Sealed thermally insulated tanks with membranes are known in the prior art. The walls of these tanks comprise a multilayer structure having, from the inside to the outside of the tank, at least a first-level sealing membrane and a first-level thermal insulation barrier for contact with the fluid stored in the tank and optionally a second-level membrane and a second-level thermal insulation barrier.

[0004] The thermal insulation barrier comprises a plurality of insulating plates juxtaposed in parallel rows.The first and second level membranes are supported by the insulating plates of the first and second level thermal insulation barrier, respectively.

[0005] The thermal insulation panels each comprise an expanding insulating foam layer. The expanding insulating foam layer is produced by a continuous free expansion foaming process. At the output of the foam manufacturing process, the insulating foam is cut to the desired dimensions of the panels to be produced. Furthermore, the inner and outer faces of the insulating foam layer are ground flat to ensure their flatness. Subsequently, a gluing sheet is typically bonded against one and / or the other of the inner and outer faces of the expanding insulating foam layer.

[0006] The sealing membrane is a metal membrane or a composite membrane. The metal membrane is produced by means of metal sheets which are welded in situ in the tank to each other and to welding supports fixed to the inner face of the insulating panels in order to fix the metal sheets to the insulating panels. The composite membrane comprises a rigid membrane element bonded to the inner face of the insulating panels. The flexible membrane element is bonded in such a way that it straddles the rigid membrane element of the adjacent insulating panel in order to ensure the sealing of the composite membrane.

[0007] Therefore, manufacturing the wall of a sealed, thermally insulating tank with a membrane is particularly complex and requires many steps. Summary of the invention

[0008] One idea underlying the invention is to provide a method for producing the wall of a sealed, thermally insulated tank with a membrane which is relatively simple and inexpensive.

[0009] According to one embodiment, the invention provides a method for manufacturing a wall of a sealed thermally insulating tank, the wall comprising at least one thermally insulating barrier and a sealing film resting against the thermally insulating barrier, the method comprising:

[0010] - manufacturing a plurality of wall elements, the manufacturing of each wall element comprising:

[0011] - provide sealing plate;

[0012] - placing an expandable insulating foam solution against the sealing plate; and

[0013] - allowing an expandable insulating foam solution to expand against the sealing board to produce an expanded insulating foam layer adhered to the sealing board;

[0014] - anchoring said wall element, suitably manufactured, to a supporting structure; the expanded insulating foam layer of said wall element forming at least a part of the thermal insulation barrier; and

[0015] - The sealing plates of the wall elements are assembled tightly in such a way that they form at least a part of the sealing membrane.

[0016] Thus, according to this method, when manufacturing the expanded insulating foam layer, the expanded insulating foam layer for forming part of the thermal insulation barrier and the sealing plate for forming part of the sealing membrane are fixed directly to each other. This makes it possible to significantly simplify the manufacture of the wall.

[0017] Furthermore, the sealing plate forms a reference surface during foaming, so that the surface of the wall element formed by the sealing plate does not have to be ground flat to ensure its flatness, thereby making it possible to further simplify the production of the wall element.

[0018] Depending on the implementation, the method may include one or more of the following features.

[0019] According to one embodiment, the expanded insulating foam layer is a polyurethane foam (PUR) or a polyisocyanurate foam (PIR).

[0020] According to one embodiment, the expandable insulation foam solution includes at least a polyol, a polyisocyanate, and an expansion agent.

[0021] According to one embodiment, the sealing plate comprises a sealing membrane.

[0022] According to one embodiment, the step of assembling the sealing plate comprises bonding the additional sealing membrane in a manner straddling the rigid composite membrane.

[0023] According to one embodiment, the sealing membrane is a rigid composite membrane.

[0024] According to one embodiment, the rigid composite membrane comprises an aluminum sheet interposed between two layers of fibers.

[0025] Obviously, other types of sealing membranes can also be produced.

[0026] According to one embodiment, the sealing plate comprises a metal plate.

[0027] According to one embodiment, the metal sheet comprises corrugations. According to one embodiment, the metal sheet comprises two series of parallel corrugations, the corrugations in one of the two series of parallel corrugations being at right angles to the corrugations in the other series.

[0028] According to one embodiment, the metal plate has a plurality of protrusions protruding in the thickness direction relative to the plane of the metal plate.

[0029] According to one embodiment, each protrusion comprises a base forming a junction between the protrusion and the flat portion, and the protrusion comprises at least one peak, the base comprising, in the plane formed by the flat portion: a first dimension, the first dimension being equal to the diameter of the smallest circle circumscribed around the base; a second dimension, the second dimension being equal to the diameter of the largest circle inscribed in the base; and a distance between the peak and the base in the thickness direction forming the height of the protrusion. The diameter of the smallest circle circumscribed around the base is understood to be the diameter of the smallest circle that is located around the base and is located on the outside and has at least two points of intersection with the base so that the circle surrounds the base without cutting it. For example, in the case of a triangular base, the circle is centered at the intersection of the perpendicular bisectors of the sides of the base. The diameter of the largest circle inscribed in the base is understood to be the diameter of the largest circle that is located inside the base and has at least two points of intersection with the base so that the circle is completely located in the base without cutting it. For example, in the case of a triangular base, the circle is centered at the intersection of the bisectors of the base.

[0030] According to one embodiment, the metal plate comprises at least one projection in all directions of the plane.

[0031] According to one embodiment, the height of the protrusion is less than 20 mm, advantageously between 8 mm and 20 mm, preferably between 10 mm and 14 mm.

[0032] According to one embodiment, each protrusion is spaced apart from adjacent protrusions in all directions of the plane by a distance less than or equal to 2 times the first dimension of the base.

[0033] According to one embodiment, the ratio of the first dimension of the base to the height of the protrusion is less than or equal to 2.

[0034] According to one embodiment, the ratio of the second dimension of the base to the height of the protrusion is less than or equal to 0.6.

[0035] According to one embodiment, the projection is produced by forging, preferably by drawing, or by stamping, die-stamping or the like.

[0036] According to one embodiment, the thickness of the metal plate is between 0.5 mm and 2 mm.

[0037] According to one embodiment, the metal plate is produced from a metal material having a Young's modulus between 130 GPa and 230 GPa.

[0038] According to one embodiment, the metal plate is produced from a metal material having a yield strength greater than 170 MPa.

[0039] According to one embodiment, the metal plate is produced from stainless steel or high manganese steel.

[0040] Thus, for stainless steel with a Young's modulus of 200 GPa, the minimum thickness of the plate is thus approximately equal to 0.58 mm. For high-manganese steel with a Young's modulus of 170 GPa, the minimum thickness of the plate is thus approximately equal to 0.68 mm.

[0041] According to one embodiment, the number of protrusions per linear meter of the metal plate is N. 凸起部 In the following range:

[0042]

[0043] Where α is the thermal expansion coefficient of the metal plate, in K -1 , ΔT is the temperature difference between the ambient temperature and the temperature of the fluid stored in the tank, in K, and h is the height of the protrusion, in mm.

[0044] According to one embodiment, each raised portion has a pyramidal or semi-elliptical shape, for example a hemisphere or a pyramid with a square base.

[0045] According to one embodiment, the base has an oval shape, for example a circle, or has a polygonal shape.

[0046] According to one embodiment, each protrusion has a shape that flares towards the base.

[0047] According to one embodiment, the step of assembling the sealing plates comprises welding the metal plates tightly to each other.

[0048] According to one embodiment, the metal sheets are welded edge to edge.

[0049] According to another embodiment, the metal sheets are welded to each other by means of an additional metal component which is welded in such a way as to straddle the metal sheets of adjacent wall elements.

[0050] According to one embodiment, the sealing plate comprises a metal plate and one or more anchoring members for anchoring the first-level insulating plate to said wall element.

[0051] According to one embodiment, the sealing plate comprises a metal plate and one or more anchoring plates.

[0052] According to one embodiment, the sealing plate comprises one or more thicker regions in which one or more screw holes for receiving the fixing studs are formed.

[0053] According to one embodiment, the sealing plate comprises a metal plate and one or more heat protection bands along the edges of the metal plate.

[0054] According to a variant embodiment, not illustrated and not covered by the claims, the expandable insulating foam solution is not expanded against the metal sheet. The metal sheet is therefore bonded to the expanding insulating foam layer after its formation. This variant embodiment can be freely combined with the various features of the embodiments described in this document, and in particular with the following features:

[0055] - one or more heat protection tapes are positioned along the edge of the metal sheet bonded to the expanded insulating foam layer;

[0056] - the metal plate comprises one or more anchoring members for anchoring the first-level insulating plate to said wall element; and / or

[0057] The metal plate comprises one or more thicker areas in which one or more screw holes are formed for receiving fixing studs.

[0058] According to one embodiment, the expandable insulation foam solution is expanded in a laminator that constrains the expansion of the insulation foam solution.

[0059] According to one embodiment, the laminator is a double-belt laminator comprising a lower belt, an upper belt and side walls, which together form a channel having a rectangular cross-section.

[0060] According to one embodiment, the laminator is arranged so that the restriction of the expansion of the expandable insulating foam solution produces an expanded insulating foam layer whose volume at the output of the laminator corresponds to between 92% and 99% of the expanded volume of the expandable insulating foam solution in the case of free expansion. This makes it possible to impart an excellent level of mechanical properties to the expanded insulating foam layer.

[0061] According to one embodiment, the manufacturing of each wall element comprises depositing one or more fiber reinforcements on the sealing plate and impregnating said fiber reinforcements when the expandable insulating foam solution is placed against the sealing plate.

[0062] According to one embodiment, the fiber reinforcement is a fiber mat.

[0063] According to one embodiment, the fiber reinforcements are deposited parallel to each other and to the sealing plate.

[0064] According to one embodiment, the fiber reinforcement comprises glass fibers which are bound together by a resin, such as a polyurethane resin.

[0065] According to one embodiment, during the production of each wall element, a support is produced so as to be adhered to the face of the expanded insulating foam layer opposite to the sealing plate.

[0066] According to one embodiment, the support is a glued sheet.

[0067] According to one embodiment, the support is bonded to the expanded polymer foam layer.

[0068] According to one embodiment, the sealing sheet is placed on a conveyor belt, the expandable insulating foam solution is deposited against the sealing sheet resting on the conveyor belt, and the sealing sheet and the insulating foam solution are guided to a laminator by means of the conveyor belt.

[0069] According to one embodiment, at least one face of the expanded insulating foam layer opposite the sealing plate is processed. Advantageously, when a laminator is used to limit the expansion of the insulating foam solution, the face of the expanded insulating foam layer opposite the sealing plate is processed at the output of the laminator.

[0070] According to one embodiment, the present invention also provides a wall for sealing a thermally insulating tank obtained by the above method, the wall comprising a plurality of wall elements, each wall element comprising a sealing plate and an expanded thermally insulating foam layer directly adhered to the sealing plate, the wall elements being anchored to a supporting structure and arranged side by side with each other so that the expanded thermally insulating foam layer forms a thermally insulating barrier, and the sealing plates of the wall elements being tightly assembled with each other to form at least a portion of a sealing membrane.

[0071] Since the expanded insulation foam layer is adhered directly to the sealing board, there is no intermediate adhesive layer.

[0072] According to one embodiment, the present invention also provides a sealed thermally insulated tank for storing fluid, the sealed thermally insulated tank comprising the above-mentioned wall.

[0073] Such tanks may form part of an onshore storage facility, for example for storing LNG, or be installed in a floating, coastal or deepwater structure, in particular for use in methane carriers, floating storage and regasification units (FSRU), floating production and storage offshore units (FPSO) and the like.

[0074] According to one embodiment, the present invention provides a vessel for transporting a fluid, the vessel comprising a double hull and the above-mentioned tank arranged in the double hull.

[0075] According to one embodiment, the present invention also provides a method for loading or unloading such a vessel, in which method fluid is transferred from a floating or onshore storage facility to a tank of the vessel through an insulated pipe or from a tank of the vessel to a floating or onshore storage facility through an insulated pipe.

[0076] According to one embodiment, the present invention also provides a system for transmitting fluid, which includes: the above-mentioned ship; an insulating pipe arranged so that a tank installed in the hull of the ship is connected to a floating or onshore storage device; and a pump for driving the fluid from the floating or onshore storage device through the insulating pipe to the tank of the ship or from the tank of the ship through the insulating pipe to the floating or onshore storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The invention will be better understood and other objects, details, features and advantages of the invention will become more apparent from the following description of several specific embodiments of the invention given in a purely illustrative and non-limiting manner with reference to the accompanying drawings.

[0078] [ Figure 1 ] Figure 1 is a schematic diagram of a multilayer structure of a tank wall with a membrane.

[0079] [ Figure 2 ] Figure 2 is a schematic diagram of a wall element associated with a sealing plate for forming a portion of a sealing membrane and an expanded insulating foam layer for forming a portion of a thermal insulation barrier.

[0080] [ Figure 3 ] Figure 3 is a schematic diagram of an apparatus for manufacturing wall elements.

[0081] [ Figure 4 ] Figure 4 A wall element according to another embodiment is illustrated.

[0082] [ Figure 5 ] Figure 5 Detailed example Figure 4 Sealing plate of the wall element.

[0083] [ Figure 6 ] Figure 6 yes Figure 5 Schematic cross-sectional view on line II-II.

[0084] [ Figure 7 ] Figure 7 is based on Figure 5 Detailed view of the raised portion of a variant embodiment of the sealing plate.

[0085] [ Figure 8 ] Figure 8 yes Figure 7 Cross-sectional view on plane IV-IV.

[0086] [ Fig. 9 ] Fig. 9 Schematically shows the Figure 4 A wall element of a variant embodiment.

[0087] [ Fig.10 ] Fig.10 The region of a second primary wall element for anchoring a first primary insulation panel according to one embodiment is schematically represented.

[0088] [ Fig.11 ] Fig.11 A wall element according to a further embodiment is schematically represented.

[0089] [ Fig.12 ] Fig.12 A wall element according to a further embodiment is schematically represented.

[0090] [ Fig.13 ] Fig.13 yes Fig.10 A perspective view of the corrugated metal sheet of the wall element.

[0091] [ Fig.14 ] Fig.14 is a schematic cross-sectional view of a methane carrier tank and the dock used to load / unload the tank. DETAILED DESCRIPTION

[0092] Figure 1The structure of the wall 31 of the tank with the membrane is shown. The wall has a multi-layer structure and comprises, from the outside to the inside of the tank: a second-level thermal insulation barrier 14, which includes a second-level thermal insulation plate 17 anchored to a support structure 15; a second-level membrane 13, which rests against the second-level thermal insulation barrier 14; a first-level thermal insulation barrier 12, which includes a first-level insulation plate 14, which rests against the second-level membrane 13 and is anchored to the support structure 15 or the second-level thermal insulation plate 14; and a first-level membrane 1, which rests against the first-level thermal insulation barrier 12 and is used to contact with the liquefied gas contained in the tank.

[0093] In order to produce such a wall, a number of wall elements 32 are first produced, one of which is shown in FIG. Figure 2 Each wall element 32 comprises a sealing plate 33 for forming a part of one of the first-stage membrane 1 and the second-stage membrane 13 and an expanding insulating foam layer 34 for forming a part of the corresponding thermal insulation barrier.

[0094] The following will be combined Figure 3 A method for producing such a wall element 32 and a device 35 allowing this method to be implemented are described.

[0095] The apparatus 35 comprises a conveyor belt 36, a dispenser 37 for dispensing an expandable insulating foam solution, and a laminator 38. The conveyor belt 36 is used to receive a sealing plate 33 for forming a portion of one of the primary film 1 and the secondary film 13 of the tank wall. According to one embodiment, the sealing plate 33 has been previously cut to the size of the wall element 32 to be produced before being arranged on the conveyor belt 36. According to another embodiment, after the expansion insulating foam layer 34 is formed and expanded, the sealing plate 33 is continuously arranged on the conveyor belt 36 and cut to the size of the wall element 32 to be produced.

[0096] In addition, if Figure 3 , the conveyor belt 36 is also used to receive a fiber reinforcement 39, such as a fiber mat. In this embodiment, the fiber reinforcement 39 is provided in the form of a roll. The fiber reinforcement 39 is unrolled and becomes parallel to each other against the sealing plate 33. According to one embodiment, the fiber reinforcement 39 is previously cut to the size of the wall element 32 to be produced. According to another embodiment, after the expansion insulating foam layer 34 is formed and expanded, the fiber reinforcement 39 is continuously arranged and cut. The fiber reinforcement 39 includes, for example, glass fibers bonded together by a resin, such as a polyurethane resin.

[0097] A dispenser 37 is located above the conveyor belt 36. The dispenser 37 is used to dispense an expandable insulating foam solution 40 onto the fiber reinforcement 39 and the sealing plate 33. The expandable insulating foam solution 40 comprises a mixture of chemical components, an inflating agent and other possible functional agents that allow the formation of an expandable insulating foam. The components of the expandable foam solution are mixed in a mixer not shown before being directed to the dispenser 37.

[0098] According to one embodiment, the expanded insulation foam to be produced is a polyurethane foam (PUR) or a polyisocyanurate foam (PIR). In addition, the expanded insulation foam solution comprises at least a polyol, a polyisocyanate and an expansion agent, which is also called an inflating agent.

[0099] The polyol is selected, for example, from polyether polyols, polyester polyols and mixtures thereof. The polyisocyanate is selected, for example, from aromatic, aliphatic, alicyclic and aromatic aliphatic polyisocyanates and mixtures thereof.

[0100] The inflating agent comprises a physical and / or chemical expansion agent, preferably, the inflating agent comprises a combination of physical and chemical expansion agents. According to one embodiment, the physical expansion agent is selected from: alkanes and cycloalkanes having at least 4 carbon atoms, dialkyl ethers, esters, ketones, acetals, fluoroalkanes and fluoroalkenes having between 1 and 8 carbon atoms, and tetraalkylsilanes having between 1 and 3 carbon atoms in the alkyl chain, or mixtures thereof, the tetraalkylsilane being in particular tetramethylsilane. According to another embodiment, the selected physical expansion agent is 1,1,1,3,3-pentafluoropropane or HFC-245fa (sold by the company Honeywell), 1,1,1,3,3-pentafluorobutane or 365mfc (for example sold by the company Solvay). 365mfc), 2,3,3,3-tetrafluoropropylene, 1,1,1,2,3,3,3-heptafluoropropane (also known as HFC-227ea internationally, for example sold by Dupont), 1,1,1,4,4,4-hexafluorobutene (for example HFO FEA1100 sold by Dupont), trans-1-chloro-3,3,3-trifluoropropylene (Solstice LBA-Honeywell), or a mixture thereof. According to one embodiment, the chemical expansion agent comprises water.

[0101] According to one embodiment, the expandable insulating foam solution 40 includes a reaction catalyst, which may be selected from tertiary amines such as N,N-dimethylcyclohexylamine or N,N-dimethylbenzylamine, or may be selected from organometallic compounds based on bismuth, potassium or tin.

[0102] The distributor 37 is arranged to distribute the expandable insulating foam solution 40 uniformly over the width of the sealing plate 33 onto the sealing plate 33. To this end, according to one embodiment, the distributor 37 comprises one or more nozzles that can be moved transversely, i.e. horizontally and at right angles to the advancement direction of the conveyor 36. According to another embodiment, the distributor 37 comprises a plurality of nozzles uniformly distributed in a transverse horizontal direction and at right angles to the advancement direction of the conveyor 36.

[0103] The expandable insulating foam solution 40, and in particular the viscosity of the expandable insulating foam solution, is determined so that the solution impregnates the fiber reinforcement 39 and comes into contact against the sealing plate 33 during an emulsification time, which corresponds to the period between dispensing the expandable insulating foam solution 40 and the beginning of the expansion of the foam. Therefore, as the expanding insulating foam layer 34 is expanded to come into contact with the sealing plate 33, the expanding insulating foam layer 34 and the sealing plate 33 adhere to each other.

[0104] The advancement rate of the conveyor belt 36 and the characteristics of the expandable insulating foam solution 40 are determined so that: when the assembly including the sealing plate 33, the fiber reinforcement 39 and the insulating foam is introduced into the laminator 38, the emulsification time has passed, but the expansion of the expandable insulating foam has not yet been completed. It should be noted that if the mixer is arranged close to the dispenser 37, the travel time between mixing the components and dispensing the components through the dispenser 37 can be ignored.

[0105] In an embodiment not shown, the device 35 comprises, upstream of the laminator 38, a pressure system with one or more rollers, which are arranged above the conveyor belt 36 and supported against the fiber reinforcement 39. The pressure system makes it possible in particular to control the thickness of the foam when it enters the laminator 38 and to provide a top surface with good flatness.

[0106] The laminator 38 makes it possible to limit the expansion of the foam and thus gradually harden the expanded insulating foam layer 34 in the desired form. According to one embodiment, the laminator 38 is a double belt laminator 38, known by the abbreviation DBL. This double belt laminator 38 comprises a lower belt 41, an upper belt 42 and a Figure 3 The side walls not shown in the figure, the lower belt 41, the upper belt 42 and the side walls together form a channel with a rectangular or square cross-section.

[0107] Advantageously, the positioning of the channel walls of the laminator 38 is defined so that the restriction of the foam expansion results in a foam volume at the output of the laminator 38 corresponding to 92% to 99% of the expanded volume of the same foam in the case of free expansion, i.e. without the restriction of the walls of the laminator 38. Thus, an expanded insulating foam layer 34 is obtained in which at least 60%, generally more than 80%, even more than 90% of the cells storing a gas of low thermal conductivity extend longitudinally on an axis parallel to the thickness axis of the expanded insulating foam layer 34. In addition, the laminator also contributes to a more uniform distribution of the fiber reinforcement 39 in the foam block. This makes it possible to obtain an expanded insulating foam layer 34 exhibiting excellent mechanical properties.

[0108] At the output of the laminator 38, the insulating polymer foam layer is processed in order, on the one hand, to enable the wall element 32 to be cut to the desired size, and on the other hand, to ensure the flatness of at least the face of the expanded insulating polymer foam layer opposite the sealing plate 33. By using the sealing plate 33 forming the reference surface, the face of the wall element 32 formed by the sealing plate 33 does not have to be ground flat to ensure its flatness, which makes it possible to further simplify the production of the wall element 32.

[0109] According to another embodiment not shown, the expansion of the expandable insulating foam is not carried out in a laminator. In other words, the expansion is carried out on a device comprising a lower belt and side walls but not an upper belt for limiting the expansion of the expandable insulating foam. This situation is called free expansion.

[0110] In an embodiment not shown, the device comprises, upstream of the dispenser 37, an adhesive dispenser which makes it possible to dispense adhesive onto the sealing plate 33 and thus makes it possible to promote adhesion between the sealing plate 33 and the expanded insulating foam layer 34. For example, the adhesive can be dispensed in the form of drops or in the form of a continuous or discontinuous film.

[0111] According to an advantageous embodiment, Figure 2 , the wall element 32 further comprises a support 43 which is adhered to the expanded insulating foam layer 34 on the face opposite to the sealing plate 33. According to one embodiment, the support 43 is a glue sheet 43. At the output of the laminator 38, the support 43 is bonded to the expanded polymer foam layer. This is advantageous because it allows the face of the expanded insulating foam layer 34 for receiving the support 43 to be machined before it is bonded, making it possible to obtain low tolerances on the thickness of the wall element 32 thus produced.

[0112] Subsequently, one or more wall elements 32 produced by means of the above method are anchored to the support structure 15, directly if the wall elements 32 are second-level wall elements, or by being fixed to the second-level membrane 13 or to the second-level thermal insulation barrier 14 if the wall elements 32 are first-level wall elements. The wall elements 32 are advantageously parallelepiped in shape and are juxtaposed in parallel rows. The gaps between the expanded insulating foam layers 34 of the wall elements 32 are filled with insulating fillers so as to form one of the thermal insulation barriers 12, 14. In addition, the sealing plates 33 are tightly coupled to each other to form one of the membranes 1, 13.

[0113] According to one embodiment, the sealing plate 33 comprises a membrane. According to one embodiment, the membrane is a composite membrane comprising an aluminum sheet interposed between a glass fiber layer and a resin layer. Such a composite membrane is particularly known under the trademark In this case, the sealing plate 33 is used to form part of the secondary membrane 13. In addition, the wall element 32 is a secondary wall element and is therefore fixed directly to the support structure 15. The wall element 32 is anchored to the support structure 15, for example by means of resin beads and / or studs welded to the support structure 15, as described, for example, in document FR2691520.

[0114] According to one embodiment, the expandable insulating foam solution 40 is directly in contact against the composite membrane during the manufacture of the wall element 32. According to another embodiment, the face of the composite membrane that is to be placed in contact with the expandable insulating foam solution 40 is previously coated with an adhesive, so that the adhesion of the expandable insulating foam layer 34 on the composite membrane can be further increased. According to yet another embodiment, the sealing plate 33 further includes a glue layer that is bonded to the composite membrane and to which the expandable insulating foam layer 34 is adhered.

[0115] When the wall elements 32 are fixed to the support structure 15 , the bonded flexible composite membranes are welded in the form of composite membranes straddling adjacent wall elements 32 to ensure a leaktight connection and thus produce the secondary membrane 13 .

[0116] about Figures 4 to 6 According to another embodiment, a wall element is described. This embodiment differs from the above-described embodiment in that the sealing plate 33 does not comprise a composite membrane, but rather a metal plate 2 with a projection 4 .

[0117] exist Figure 5 The metal plate 2 shown in detail in FIG. 1 comprises a flat portion 3 defining a plate plane and a plurality of protrusions 4 protruding from the flat portion 3 in a thickness direction at right angles to the plate plane.

[0118] The projections 4 are spaced apart from one another and distributed over the entire metal plate 2, making it impossible to draw a straight line in the plane of the plate without passing through the projections 4. In fact, in order to ensure that the metal plate 2 shrinks when the tank is filled or expands when the tank is emptied, the metal plate 2 has projections in all directions of the plate plane. Therefore, the flat parts 3 separate the projections 4 from one another. Each projection 4 comprises a base 5 and at least one peak 6. The projections are produced by forging, preferably by drawing, or by stamping, die pressing, etc. According to one embodiment, the height of the projections is less than 20 mm, for example about 10 mm.

[0119] To produce the wall element 32, as Figure 4 As shown, the metal plate 2 is arranged on the conveyor belt 36 so that the protrusions 4 protrude downward. The expandable insulating foam solution 40 penetrates into the protrusions 4, which makes it possible to ensure good adhesion of the metal plate 2 to the expanded insulating foam layer 34. According to one embodiment, in order to prevent the protrusions 4 from being crushed when the metal plate 2 enters the laminator 38, the metal plate 2 is positioned on the conveyor belt 36 by means of a support having cavities, the shape of which each corresponds to one of the protrusions 4.

[0120] like Figure 5 and Figure 6 As shown in , the protrusion 4 has a circular base 5 and has a single peak 6, thereby forming a hemispherical or semi-elliptical shape. Here, the protrusions 4 are evenly distributed on the metal plate 2, but in another embodiment not shown, the protrusions 4 can be unevenly distributed.

[0121] Figure 6 It indicated Figure 5 4 , in order to indicate the various dimensions of the protrusion 4. The base 5 comprises, in the plane of the plate, a first dimension 7 and a second dimension 8, which, in the case of the first embodiment, are equal. The first dimension 7 is equal to the diameter of the smallest circle circumscribed around the base 5, while the second dimension 8 is equal to the diameter of the largest circle inscribed in the base 5. Furthermore, the distance between the peak 6 and the base 5 in the thickness direction of the metal plate 2 defines the height 9 of the protrusion 4.

[0122] exist Figure 6 In the embodiment, each protrusion 4 is spaced apart from an adjacent protrusion 4 by a distance less than or equal to 1 times the first dimension 7 of the base 5. The ratio of the second dimension 8 of the base 5 to the height 9 of the protrusion 4 is approximately equal to 3.33. Therefore, the ratio of the first dimension 7 of the base 5 to the height 9 of the protrusion 4 is approximately equal to 0.3.

[0123] Such a wall element 32 may form a secondary wall element or a primary wall element.When the wall element 32 is anchored to the support structure 15, the metal sheets 2 are tightly welded to each other in an edge-to-edge manner.

[0124] Figure 7 and Figure 8 express Figures 4 to 6 A variant embodiment of the protrusion 4 of the metal plate 2. In this variant embodiment, the shape of the base 5 of the protrusion 4 is different from the shape of the base of the protrusion in the first embodiment. In fact, the base 5 here is a quadrilateral shape, which has a larger dimension 7 formed by the diagonal of the quadrilateral and a smaller dimension 8 formed by the smallest side of the quadrilateral. Here, the ratio of the first dimension 7 of the base 5 to the second dimension 8 of the base 5 is approximately equal to 1.4, while the ratio of the second dimension 8 of the base 5 to the height 9 of the protrusion 4 is approximately equal to 2.5. Therefore, the ratio of the first dimension 7 of the base 5 to the height 9 of the protrusion 4 is approximately equal to 0.56.

[0125] In the first two embodiments, the metal plate 2 comprises protrusions of the same shape and size from one metal plate to another. In other embodiments not illustrated, the protrusions 4 may have different shapes and sizes respecting the above ratios, and the metal plate 2 may also comprise more than two different series of protrusions.

[0126] Fig. 9 Illustrated based on Figure 4 A wall element 32 of a variant embodiment of the present invention. The wall element 32 comprises a heat protection tape 52 below the area of ​​the metal plate 2 for welding with the metal plate 2 of the adjacent wall element 32. The heat protection tape 52 makes it possible to protect the expanding insulating foam layer 34 from the temperature that may decompose the expanding insulating foam layer during the operation of welding the metal plates 2 to each other. In order to produce such a wall element 32, the sealing plate 33 to which the expandable insulating foam solution 40 is dispensed comprises the metal plate 2 and the heat protection tape 52, which is bonded to the metal plate 2 on the face of the metal plate 2 for receiving the expandable insulating foam solution 40. The heat protection tape 52 is, for example, a composite tape comprising an aluminum sheet interposed between a glass fiber layer and a resin layer.

[0127] Furthermore, the wall element 32 is a second-level wall element. Fig. 9 The metal plate 2 shown in Figure 3 incorporates one or more anchoring elements 49 for anchoring the primary insulating plate to said wall element 32. The anchoring elements 49 are for example threaded studs fixed to the metal plate, or threaded nuts for receiving threaded studs.

[0128] about Fig.10, illustrates in detail a region of a wall element 32 according to one embodiment. In this embodiment, the wall element 32 comprises an anchoring plate 50 in the region for receiving the first-level plate anchoring means. This anchoring plate 50 is arranged between the metal plate 2 and the layer of expanded insulating polymer foam 34 and makes it possible to locally reinforce the metal plate 2. According to one embodiment, one or more blind nuts 51 are fixed to the reinforcement plate 50. To this end, according to the variant embodiment shown, the nuts 51 have a thread that cooperates with a hole formed in the anchoring plate 50.

[0129] The nut 51 comprises a collar which makes it possible to sandwich the metal plate 2 between the collar and the anchoring plate 50. The collar is welded to the metal plate 2 at the periphery to ensure tightness. Furthermore, the nut 51 has a threaded blind hole for receiving the fixing studs of the insulating plate of the first-level thermal insulation barrier.

[0130] To produce such a wall element 32, the sealing plate 33 on which the expandable insulating foam solution 40 is dispensed comprises the metal plate 2, the reinforcement plate 50 and the blind nuts 51, as described above.

[0131] According to a variant embodiment not shown, the anchoring plate 50 is mounted in a recess formed in the plywood. In this case, the sealing plate 33 comprises a metal plate 2, a reinforcing plate 50, blind nuts 51 and a plywood against which the expandable insulating foam solution 40 is dispensed.

[0132] about Fig.11 , illustrates in detail the regions of the wall element 32 according to a variant embodiment. In this embodiment, the sealing plate 33 comprises one or more thicker regions 53 in which one or more screw holes 54 are formed for receiving fixing studs of the first-level insulation plate.

[0133] according to Fig.12 and Fig.13 In another embodiment shown, the sealing plate 33 is a corrugated metal plate 44. This corrugated metal plate 44 is Fig.11 It is represented by a three-dimensional diagram.

[0134] The corrugated metal sheet 44 comprises a first series of parallel corrugations 45 extending in the y direction, referred to as low corrugations, and a second series of parallel corrugations 46 extending in the x direction, referred to as high corrugations. The x and y directions of the series of corrugations are at right angles. The corrugated metal sheet 44 comprises a plurality of flat surfaces 47 between the corrugations 45, 46. At each intersection between the low corrugations 45 and the high corrugations 46, the metal sheet comprises a node area 48.

[0135] The corrugated metal plate 44 can be made of stainless steel, aluminum, That is, the corrugated metal sheet 44 can be made of a material with a coefficient of expansion of generally 1.2×10 -6 K -1 Up to 2×10 -6 K -1 An alloy between iron and nickel, or with a coefficient of expansion usually about 7×10 -6 K -1的 The steel is made of an iron alloy with a high manganese content. However, the use of other metals or alloys is also conceivable.

[0136] Advantageously, when the sealing plate 33 is such a corrugated metal plate 44, the corrugated metal plate 44 is positioned on the conveyor belt 36 by means of a support having a cavity corresponding to the shape of the corrugated portions 45, 46 and in which the corrugated portions are inserted. This makes it possible to prevent the corrugated portions 45, 46 from being crushed when the corrugated metal plate 44 enters the laminator 38.

[0137] like Fig.12 As shown in FIG. 4 , the expanded insulating foam layer 34 penetrates into the corrugations 45 , 46 , which makes it possible to ensure, in particular, good adhesion of the corrugated metal sheet 44 to the expanded insulating foam layer 34 .

[0138] According to one embodiment, the corrugated metal sheet 44 is used to form a portion of the primary membrane 1, and the expanded insulating foam layer 34 is used to form a portion of the primary thermal insulation barrier 12. According to another embodiment, the corrugated metal sheet 44 is used to form a portion of the secondary membrane 13, and the expanded insulating foam layer 34 is used to form a portion of the secondary thermal insulation barrier 14.

[0139] When the wall elements 32 have been fixed to the supporting structure 15, the corrugated metal sheets 44 of the wall elements 32 are tightly connected to each other by welding them edge to edge or by means of additional metal parts, which are welded to the corrugated metal plates 44 of adjacent wall elements 32 in the form of straddling the corrugated metal plates 44 of adjacent wall elements 32.

[0140] Reference Fig.14 , a cross-sectional view of a methane carrier 170 shows a sealed, generally prismatically shaped, insulated tank 171 installed in a double hull 172 of the vessel. The wall of the tank 171 includes a first-stage membrane for contacting the LNG contained in the tank, a second-stage membrane arranged between the first-stage membrane and the double hull 172 of the vessel, and two thermal insulation barriers arranged between the first-stage membrane and the second-stage membrane and between the second-stage membrane and the double hull 172, respectively.

[0141] In a manner known per se, a loading / unloading pipeline 173 arranged on the top deck of the vessel can be connected to a marine or port terminal by means of appropriate connectors in order to transfer LNG cargo from or to the tank 171 .

[0142] Fig.14 Also shown is an example of a marine terminal, which includes a loading and unloading station 175, a submarine pipeline 176 and an onshore equipment 177. The loading and unloading station 175 is a fixed offshore equipment including a mobile arm 174 and a lifting member 178 supporting the mobile arm 174. The mobile arm 174 carries a bundle of insulated flexible pipes 179 that can be connected to the loading / unloading pipeline 173. The steerable mobile arm 174 is suitable for all methane carrier templates. The connecting pipeline, not shown, extends in the lifting member 178. The loading and unloading station 175 allows the methane carrier 170 to be loaded and unloaded from the onshore equipment 177, or the onshore equipment 177 to be loaded and unloaded from the methane carrier. The onshore equipment includes a liquefied gas tank 180 and a connecting pipeline 181 connected to the loading and unloading station 175 through a submarine pipeline 176. The subsea pipeline 176 allows the liquefied gas to be transported over long distances, such as 5 km, between the loading or unloading station 175 and the onshore facility 177, which enables the methane tanker 170 to remain at a great distance from the coast during loading and unloading operations.

[0143] In order to generate the pressure required for the transfer of the liquefied gas, a pump embedded in the vessel 170 and / or a pump equipped with the onshore installation 177 and / or a pump equipped with the loading and unloading station 175 is used.

[0144] Although the invention has been described with respect to a few specific embodiments, it is quite clear that the invention is by no means limited thereto and that the invention comprises all technical equivalents of the means described and combinations thereof, as long as these fall within the framework of the invention as claimed.

[0145] Use of the verb "comprise" or "include" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim.

[0146] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims

1. A method for manufacturing a wall (31) of a sealed thermally insulated tank for storing and / or transporting liquefied gas, the wall (31) comprising at least one thermally insulating barrier (12, 14) and a sealing film (1, 13) resting against the thermally insulating barrier, the method comprising: - manufacturing a plurality of wall elements (32), the manufacturing of each wall element (32) comprising: - providing a sealing plate (33); - placing an expandable insulating foam solution (40) against the sealing plate (33); and - causing the expandable insulating foam solution (40) to expand against the sealing plate (33) to produce an expanded insulating foam layer (34) adhered to the sealing plate (33); - anchoring the wall element (32) of suitable manufacture to a supporting structure (15); the expanded insulating foam layer (34) of the wall element (32) forming at least a part of the thermal insulation barrier (12, 14); and - tightly assembling the sealing plate (33) of the wall element (32) such that the sealing plate (33) forms at least a part of the sealing membrane (1, 13).

2. The method according to claim 1, wherein: The sealing plate (33) comprises a sealing membrane.

3. The method according to claim 2, wherein: The step of assembling the sealing plate comprises bonding an additional membrane in such a manner as to straddle the sealing membrane of the wall element (32).

4. The method according to claim 2 or 3, wherein: The sealing membrane is a rigid composite membrane comprising an aluminum sheet interposed between two layers of fibers.

5. The method according to claim 1, wherein: The sealing plate comprises a metal plate (2, 44).

6. The method according to claim 5, wherein: The metal plate includes corrugations (45, 46).

7. The method according to claim 5, wherein: The metal plate has a plurality of protrusions (4) protruding in a thickness direction relative to a plane of the metal plate.

8. The method according to any one of claims 5 to 7, wherein: The step of assembling the sealing plate comprises welding the metal plates (2, 44) tightly to each other.

9. The method according to any one of claims 1 to 3, wherein: The expandable insulating foam solution (40) is expanded in a laminator (38) that restricts the expansion of the expandable insulating foam solution (40).

10. The method according to claim 9, wherein: The laminator (38) is a double-belt laminator, which includes a lower belt (41), an upper belt (42) and side walls, wherein the lower belt (41), the upper belt (42) and the side walls together form a channel with a rectangular cross-section.

11. The method according to claim 9, wherein: The laminator (38) is arranged so that the restriction of the expansion of the expandable insulating foam solution (40) produces an expanded insulating foam layer (34) having a volume at the output of the laminator (38) corresponding to between 92% and 99% of the expanded volume of the expandable insulating foam solution (40) under free expansion.

12. The method according to claim 10, wherein: The sealing plate (33) is placed on a conveyor belt (36), the expandable insulating foam solution (40) is deposited against the sealing plate (33) resting on the conveyor belt (36), and the sealing plate (33) and the expandable insulating foam solution (40) are guided to the laminator (38) by means of the conveyor belt (36).

13. The method according to any one of claims 1 to 3, wherein: The manufacture of each wall element (32) comprises depositing one or more fiber reinforcements (39) on the sealing plate (33) and impregnating the fiber reinforcements (39) when the expandable insulating foam solution (40) is placed against the sealing plate (33).

14. The method according to any one of claims 1 to 3, wherein: During the manufacture of each wall element (32), a support (43) is produced so as to be adhered to the face of the expanded insulating foam layer (34) opposite to the sealing plate (33).

15. The method according to claim 14, wherein: The support member (43) is bonded to the expanded insulating foam layer (34).

16. The method according to any one of claims 1 to 3, wherein: At least one surface of the expanded insulating foam layer (34) opposite to the sealing plate (33) is processed.

17. A wall of a sealed thermally insulated tank for storing and / or transporting liquefied gas obtained by a method according to any one of claims 1 to 16, the wall (31) comprising a plurality of wall elements (32), each wall element (32) comprising a sealing plate (33) and an expanding insulating foam layer (34), the expanding insulating foam layer (34) being directly adhered to the sealing plate (33) without an intermediate adhesive layer, the wall elements (32) being anchored to a supporting structure (15) and arranged side by side with each other so that the expanding insulating foam layer (34) forms a thermal insulation barrier (12, 14), the sealing plates (33) of the wall elements (32) being tightly assembled with each other to form at least a part of a sealing membrane (1, 13).

18. A sealed thermally insulated tank for storing a fluid, comprising at least one wall (31) according to claim 17.

19. A vessel (170) for transporting fluids, the vessel (170) comprising a double hull (172) and a sealed thermally insulated tank (171) according to claim 18 arranged in the double hull.

20. A transmission system for a fluid, the transmission system comprising: A vessel (170) according to claim 19; an insulating pipe (173, 179, 176, 181), which is arranged so that the sealed thermally insulated tank (171) installed in the double hull of the vessel is connected to a floating or onshore storage device (177); and a pump, which is used to drive a fluid flow from the floating or onshore storage device through the insulating pipe to the sealed thermally insulated tank of the vessel, or to drive a fluid flow from the sealed thermally insulated tank of the vessel through the insulating pipe to the floating or onshore storage device.

21. A method for loading or unloading a vessel (170) according to claim 19, wherein: The fluid is transferred from a floating or onshore storage facility (177) to the sealed thermally insulated tank (171) of the vessel through an insulated pipeline (173, 179, 176, 181), or the fluid is transferred from the sealed thermally insulated tank (171) of the vessel to the floating or onshore storage facility through the insulated pipeline.

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