Assembly of at least two foam blocks for tank insulation panels

Abstract

The invention relates to an assembly of at least two foam blocks for thermal insulation panels of a tank. The invention relates to an assembly of at least two foam blocks (20, 21), the first foam block and the second foam block having surfaces referred to as "adjacent" surfaces, the two blocks (20, 21) being arranged adjacent to each other so that the adjacent surfaces of the first foam block and the adjacent surfaces of the second foam block together form a channel having a minimum width L in a static state, the adjacent surface of one of the blocks having at least one shape or cross-section complementary to at least one shape or cross-section of the other adjacent surface, the above-mentioned width L of the closed portion being reduced by at least 15% when the two opposite upper and lower surfaces of the two foam blocks have a temperature difference of at least 40°C.

Description

Technical Field

[0001] The subject of the invention is an assembly of at least two polymer foam blocks of insulating panels of a sealed insulating tank, having technical characteristics, in particular very specific mechanical and thermal properties, taking into account the specific applications in which they are used. The invention also relates to a tank integrating such an assembly and to a ship comprising one or more such tanks integrated in a membrane structure (also known as integral tanks) or comprising self-supporting / semi-supporting A, B or C type tanks for containing extremely cold fluids, known as cryogenic fluids, such as in particular liquefied natural gas (GNL) or liquefied petroleum gas (GPL), and to a ship equipped with at least one such tank, a method for loading / unloading such a ship and a transfer system for transferring liquid products contained in such a ship.

[0002] Finally, the invention relates to a system and a method for producing a polymer foam block for such an assembly of at least two foam blocks.

[0003] The invention more particularly relates to a foam block comprising an assembly of fiber-reinforced polyurethane (PUR) foam blocks and / or polyisocyanurate (PIR) foam blocks, which are installed in an insulation board. The invention will be described below by means of such PUR foams and / or PIR foams, but the invention is not limited to such blocks and the invention can be applied to a large number of polymer blocks, whether or not these blocks are fiber-reinforced (loaded with fibers).

[0004] The polymer or polymers used are selected according to their mechanical and thermal properties, which must have very specific mechanical and thermal properties, taking into account their specific application, while being able to be produced as economically as possible. Background Art

[0005] Polyurethane (PUR) foam is a porous thermal insulation material consisting of pores storing gases with low thermal conductivity. PUR foam is used in many applications, such as in the automotive industry as flexible PUR foam or in thermal insulation as rigid PUR foam. The formation of polyurethane foam is well known to those skilled in the art. The formation of polyurethane foam involves a multi-component reaction between a polyol (a compound containing at least two hydroxyl groups), a polyisocyanurate (a compound containing at least two isocyanate-NCO functional groups) and an expansion agent (also referred to as a "blowing agent"). The condensation reaction is catalyzed in particular by compounds having alkaline properties and / or nucleophilic properties, such as tertiary amine compounds or metal-carboxylate coordination compounds (such as tin salts or bismuth salts). Polyols commonly used in the manufacture of PUR foam are usually polyether polyols or polyester polyols. Therefore, the formation of PUR foam requires a large amount of compounds.

[0006] Polyisocyanurate (PIR) and polyurethane / polyisocyanurate (PUR-PIR) foams are also used in construction (construction / renovation) and have the advantage of providing better fire resistance and higher compression resistance than PUR. The process for forming these foams is similar to the process for forming PUR foam. In particular, whether PUR foam, PIR foam or PUR-PIR foam can be obtained depends on the isocyanate / polyol ratio.

[0007] PUR foams, PIR foams and PUR-PIR foams are known to those skilled in the art. However, the addition of fibers involves specific technical problems, such as the need for good impregnation of the fibers, so that foams with a relatively high fiber content, at least locally, do not currently exist.

[0008] These PUR foams, PIR foams and PUR-PIR foams are used in the form of blocks having a parallelepiped shape, which are placed in an encapsulation structure to form an insulation board; this encapsulation structure has a sealing membrane-like member, which is usually made of stainless steel or Invar alloy, and this insulation board can usually include one or two encapsulation structures, depending on the cold liquid contained in the liquid tank (the temperature of the cold liquid).

[0009] In the technical field concerning the use of such foams for thermal insulation panels for tanks, the panels are subjected to very cold temperatures on the surfaces exposed to the interior space of the tank, for example about -160°C in the case of GNL, while the space outside the tank (usually the hull) generally has a higher ambient temperature, which is at least equal to, and in fact much higher than, the temperature of the ambient air or sea, which is believed to be about 20°C.

[0010] Currently, two adjacent polymer foam blocks are:

[0011] - housed in wooden shells of the plywood or laminate type and these wooden shells are connected together by couplings: e.g. the condition of the tank; or

[0012] - are arranged in the form of a sandwich with an upper coating and a lower coating, and the shells of these sandwiches are connected together by a complex mat or fabric, which usually includes three layers: for example, MARK This is the case with tanks.

[0013] Thus, there is currently no direct mechanical or chemical connection between adjacent polymer foam blocks.

[0014] Furthermore, in both types of construction described above, two adjacent polymer foam blocks form between them a linearly (usually vertically) extending space which, when these blocks are installed in a tank, must be blocked with glass wool or the like, in particular to prevent any thermal siphoning from occurring.

[0015] The present invention aims to respond to these drawbacks by first solving the problems related to the thermal phenomena that may occur in the space present between two adjacent foam blocks. Summary of the invention

[0016] In this context, the applicant, after various studies and analyses, has successfully developed an assembly of polymer foam blocks, wherein each of the foam blocks has shapes or cross-sections that are complementary to each other on their facing adjacent surfaces, so that when each of the foam blocks shrinks due to cooling of a liquid tank containing cryogenic liquid or the like, a significant reduction in the width of the channel separating the two blocks is observed on at least a portion (referred to as a closed portion).

[0017] Thus, when the block is in use, the temperature gradient inside the foam block is generally equal to at least 80° C., even at least 100° C., wherein the thermal environment of the block is very different between its upper surface, arranged on the content side of the tank, and its lower surface, arranged on the exterior side of the tank. Moreover, in addition to the effect of closing the passage / duct separating two adjacent blocks to prevent any negative thermal phenomena, when the surfaces of each block come into contact, this closed portion will constitute a joining member, so that the two foam blocks will remain close to each other without any bending or buckling.

[0018] According to the invention, therefore, a possibility is now provided to produce a direct mechanical connection between two adjacent foam blocks without any attachment elements.

[0019] The present invention therefore aims to remedy the disadvantages of the prior art by proposing a particularly effective solution for industrially obtaining fiber-reinforced PUR / PIR foams, which can have (very) large dimensions, whose mechanical / thermal properties are optimal and roughly similar between their initial state (at rest, the foam block is in a roughly uniform thermal environment) and their use / service state (in the use / service state, the foam block is in a non-uniform thermal environment), and whose temperature difference, based on the thickness of the block, between the upper surface (the content side of the tank) and the lower surface (the outside side of the tank) is at least equal to 40°C, or even at least equal to 80°C to 100°C.

[0020] Advantageously, with regard to the embodiment in which there is a mechanical connection between two adjacent blocks, the production costs of the thermal insulation board can be significantly reduced by eliminating some of the intermediate connection elements and due to the saving of installation / assembly time.

[0021] The invention therefore relates to an assembly of at least two polymer foam blocks of an insulation panel for sealing an insulated tank, the polymer foam being preferably a polyurethane / polyisocyanurate foam, the density of the foam block having at least opposite upper and lower surfaces and side surfaces being between 30 kg / m 3 Up to 300kg / m 3 Between the first foam block and the second foam block, there is a surface called an "adjacent" surface, and the two blocks are arranged adjacent to each other so that the adjacent side surface of the first foam block and the adjacent side surface of the second foam block form a channel or pipe between them without any mechanical attachment, and when the blocks are in a stationary state, that is, when there is no obvious temperature difference between the two opposite upper and lower surfaces of the two blocks, the channel or pipe has a minimum width L on at least one part of the channel or the pipe called the closed part, and the adjacent surfaces of the first block and the second block have at least a non-flat or non-linear shape or cross-section, which is roughly complementary to the shape or cross-section of the other adjacent surface of the first foam block or the second foam block, respectively.

[0022] According to the present invention, when the two adjacent blocks are in operation, i.e., when the liquid tank is at least partially filled with cold liquid and therefore the two relative upper and lower surfaces of the two adjacent blocks have a temperature difference of at least 40°C, preferably at least 80°C, the width L of the closed portion is reduced by at least 15%.

[0023] According to a particularly advantageous aspect of the invention, the passage or duct between the first foam block and the second foam block is "without any mechanical attachment", in other words, there is no mechanical attachment between the two blocks or through the duct or passage. The expression "mechanical attachment" refers to attachment by means of physical elements that perform the attachment function (such as screws, bolts, etc., or even connecting rods). For the sake of clarity, this mechanical attachment is different from chemical attachment, which consists of an adhesive element (such as a chemical adhesive) or an element with an adhesive coating (such as a double-sided tape or sticker).

[0024] Advantageously, the object of the present invention is to enable a protrusion of a first polymer foam block to interact with a protrusion of a second polymer foam block by bite, snap or even shape complementarity, so as to provide a direct attachment between two adjacent foam blocks (including direct attachment by means of a compressible material as described below), in particular in the working state of the liquid tank.

[0025] The expression "cold liquid" refers to a cryogenic fluid which is essentially in liquid form, such as in particular liquefied natural gas (GNL) or liquefied petroleum gas (GPL).

[0026] With respect to a tank and its operating conditions, the expression "partially filled" means that the tank has been filled to at least 20% of its maximum storage capacity. In particular, the assembly according to the invention is used in a tank capable of containing cold liquids.

[0027] The expression "minimum width L" means that the gap L represents the minimum gap at the closed part. Of course, the gaps in the channel or duct at the closed part may be the same, so that in this case the minimum gap L is equal to the gap in the channel or duct over the entire closed part, but usually, the minimum gap L includes the minimum gap existing in the channel / duct at the closed part.

[0028] The expression "a shape or cross-section that is substantially complementary to the shape (three-dimensional) or cross-section (two-dimensional) of another adjacent surface" means that one of the two shapes or the two cross-sections can fit together inside the other to form an adjacent portion, and for the two surfaces of each block-shaped piece, the adjacent portion is solid or quasi-solid, that is, in the case of a quasi-solid state, the adjacent portion formed by the two substantially complementary shapes / cross-sections fitting together is at least 70% solid, or even preferably at least 90% solid.

[0029] The invention is described below in the case where the polymer foam of the two blocks comprises polyurethane / polyisocyanurate foam. In particular, the invention is intended to be applied in particular to polymers of this type, but it is not limited to these polymers and other polymers can be envisaged which have mechanical and thermal properties which make them suitable for use in tanks for storing cryogenic liquids or the like. Furthermore, according to a preferred embodiment, in particular for obvious production reasons, the two foam blocks are formed or consist of the same polymer foam, but it is conceivable that these blocks are made of different or at least partially different polymers.

[0030] The term "block" according to the present invention is a non-limiting term. The "block" may have any shape and it does not have to be cut.

[0031] The block of polyurethane / polyisocyanurate foam, preferably fiber-reinforced polyurethane / polyisocyanurate foam, comprises pores for storing gas, polyurethane / polyisocyanurate foam and fibers, which advantageously have low thermal conductivity, accounting for at least 95% of the weight of the block.

[0032] The foam block of the present invention comprises (only) polyurethane (PUR) and / or polyisocyanurate (PIR) foam, fibers (preferably fibers of a single nature, such as glass fibers), gas trapped in the pores, and the minimum possible fraction, such as fillers or other functional additives, which accounts for at most 5% of the weight of the foam block according to the present invention, and even preferably at most 2% or 1% of the weight (thus, the fiber-reinforced polyurethane / polyisocyanurate foam block comprises pores for storing gas, polyurethane / polyisocyanurate foam and fibers that account for at least 98% or 99% of the weight of the block). In particular, the foam block according to the present invention is obtained by:

[0033] - obtained in a single foam preparation operation (mixing of the reaction components (optionally fillers / auxiliaries) with the fibers), preferably in a double belt laminator (DBL);

[0034] - obtained during the above-mentioned preparation operation, which is assisted by a cutting operation, usually performed on the upper surface of the block, so as to obtain a block of substantially parallelepiped or cubic shape.

[0035] The invention is intended to be used particularly, but not exclusively, where the foam blocks are mounted in a secondary layer, e.g. Figure 1 and Figure 2As shown, this secondary layer is generally referred to as "secondary" in an insulation panel comprising a primary insulation layer and a secondary insulation layer. For this application, the thickness or height of the foam block is preferably at least twenty-five (25) centimeters (cm), and even more preferably at least 30 cm or 35 cm.

[0036] Advantageously, the thermal properties of the fiber reinforced foam block are at least comparable to those of the non-fiber reinforced foam blocks of the prior art, more specifically, the thermal conductivity of the foam block of thickness E (measured at 20°C) is less than 30 mW / mK (milliwatts per meter Kelvin) or 0.03 W / mK, preferably less than 25 mW / mK, even more preferably less than 23 mW / mK, and the thermal conductivity is less than 20 mW / mK when the upper surface of the block is at -160°C, when the foam block is in use and the liquid tank containing the foam block contains GNL.

[0037] Therefore, the fiber reinforced foam blocks can be used both in liquid tanks integrated in supporting structures and in self-supporting / semi-supporting liquid tanks of type A, B or C as defined in the IGC Rules (IMO), i.e. as external insulation elements associated with self-supporting liquid tanks for the storage and / or transport of very cold liquids (such as GNL or GPL).

[0038] Other advantageous features of the present invention are briefly described below:

[0039] Preferably, the minimum width L is reduced by at least 50%.

[0040] Advantageously, the channel or duct has, in the cross-sectional plane P, a non-linear path.

[0041] Because the present invention makes such a non-linear path of the channel or conduit possible, any occurrence of thermosiphoning can be reduced or even eliminated.

[0042] Therefore, if Figure 6 and Figure 7 As shown, the path of the duct or channel including a cross-section along a plane of thickness of the polymer foam block is not linear, that is, the path does not extend in the form of a straight line connecting the upper surface and the lower surface, but instead includes multiple segments, vertical segments (through the thickness of the foam block), horizontal segments (through a plane perpendicular to a plane including a plane through the height or thickness of the foam block) or even inclined segments.

[0043] According to one embodiment, in the working state, the minimum width L is equal to 0, so that the two adjacent blocks are in contact at least at the closed portion.

[0044] Therefore, when there is a direct mechanical connection between adjacent blocks formed by the closed part (which in this case constitutes a joint or connecting member between two adjacent blocks), the adjacent surfaces can be prohibited or prevented from separating in the following situation, namely, when the insulation board of the sealed insulated liquid tank becomes cold, in other words, when the sealed insulated liquid tank is used to contain extremely cold fluids known as cryogenics (such as, in particular, liquefied natural gas (GNL) or liquefied petroleum gas (GPL)).

[0045] Preferably, the closed portion comprises a material having a compression capacity at least equal to 15%, preferably at least equal to 50%, and preferably, the closed portion consists of glass wool or rock wool or of an elastomer. Thus, the contact between the two polymer blocks is no longer direct, but advantageously occurs through this thin thickness of material, which makes it possible to prevent any friction or any wear of the polymer blocks at their contact points. However, such a contact between the two polymer blocks (including the contact in this case) is considered direct, since the material is capable of significant compression, so that only a very small thickness remains between the two blocks - at most about one millimeter, or at most one or two millimeters - which makes the material act only as a buffer or mechanical stress damping element between the two blocks.

[0046] According to one possibility provided by the present invention, at least one foam block, preferably the two foam blocks, is composed of fiber-reinforced foam, the average fiber density T of the fiber-reinforced foam is f Between 1% and 60% of the fiber weight, preferably the fibers are long or continuous; the fibers consist of glass fibers, basalt fibers, hemp fibers or any other organic or inorganic material; preferably, the fibers consist of glass fibers.

[0047] The term "one or more fibers" or the expression "fiber reinforcement" means that the fibers can be in two different forms:

[0048] - in the form of at least one fiber fabric in which the fibers are completely aligned in at least one direction, in other words, the fibers have at least one preferred fiber direction. The expression "fiber fabric" itself refers to a clear technical definition known to the person skilled in the art, or

[0049] - in the form of at least one fiber mat in which the fibers have no defined orientation, in other words the fibers are oriented substantially isotropically in the main planes of the layers of the mat. Likewise, the expression "fiber mat" itself refers to a clear technical definition known to the person skilled in the art.

[0050] Advantageously, said substantially complementary shapes or cross-sections consist of a convex portion and a concave portion, respectively.

[0051] According to one possibility provided by the invention, the fibers consist of glass fibers, carbon fibers or any other organic or inorganic material, preferably glass fibers, typically of a polymer, metal, ceramic, vitreous inorganic or organic nature, such as natural fibers, for example hemp or flax, preferably glass fibers.

[0052] The expression "the fibres are long to continuous (les fibres etant longues a continues)" (or "the fibres longues a continues") means that all (i.e. at least 90% of the total weight of the fibres (considered individually or agglomerated to form the equivalent of a single fibre)) of the fibres (or where appropriate an agglomeration of fibres (fibres bonded or attached to one another)) have a length of at least five (5) centimetres (cm).

[0053] Preferably, the average fiber density T f Between 2% and 25%, preferably between 6% and 20%.

[0054] According to an advantageous embodiment, said complementary shape or cross-section has a fiber density greater than said average fiber density T f The fiber density is preferably 1.2T f To 3T f The fiber density is preferably between 1.4T f Up to 2T f The fiber density between.

[0055] The average fiber density T f ” refers to the fiber density expressed as the weight of fibers relative to the total weight of the fiber-reinforced foam block, without taking into account the variable percentage of these fibers locally (within the block).

[0056] Preferably, the channel or the duct comprises a heat insulating material, and the heat insulating material is preferably glass wool.

[0057] According to one aspect of the present invention, the first foam block and the second foam block have a substantially parallelepiped or cubic shape.

[0058] It should be understood here that the foam block having such a parallelepiped or cubic shape may have, in addition to the joining members, one or more local protrusions, for example in the form of anchors as described below, or conversely, in the form of empty or hollow parts, while the foam block can still be identified as having an overall appearance of a parallelepiped or a cube.

[0059] Therefore, advantageously, the lower and / or upper surface of the block has anchors capable of engaging with engaging members of an insulation board (not shown in the drawings) so as to attach or anchor the foam block to the board, preferably, the anchors being made of a material other than foam or fiber.

[0060] These anchors are advantageously metal elements (these anchors can also be made of plastic / polymer or composite materials combining one or more polymers with ceramic and / or metal materials), for example metal elements with L-shaped hook lugs or, for example, L-shaped grooves / openings, in order to engage with an element or a portion of the insulation board surrounding or containing the fiber reinforced foam block. In the case of a membrane-type tank, this portion of the insulation board can consist of a metal sealing membrane sealing the container, for example made of stainless steel or manganese steel, or in the case of a self-supporting or semi-supporting A, B or C type tank, this portion of the insulation board can consist of a vapor barrier (with the technical function of ensuring sealing with the surrounding environment outside the tank). In one possibility provided by the invention, this element or this portion of the insulation board (in a membrane-type tank) has a notch or the like, which is used to enable engagement with a portion of the anchor for mechanically maintaining or retaining the fiber reinforced foam block with the other elements of the insulation board. Of course, these anchors may also have the function of anchoring the foam block to the hull (in the case of a membrane type tank) or to anchor the foam block to a self-supporting structure (in the case of a self-supporting tank of type A, B or C), it being understood that these anchors are anchors which subsequently exist on the lower surface of the foam block.

[0061] In the context of the present invention, these anchors are at least partially inserted into the fiber reinforcements (which form the lower layer or the upper layer of the fiber reinforcement stack) so that when the foam block is prepared / finished, these anchors can be positioned on the surface without protruding from the surface.

[0062] In the following, the terms "upper" and "lower" refer to the sens or directions given to the foam blocks after they are in place in the insulation panels of the tank. Thus, when the insulation panels are placed in the tank, the upper surface or part of the foam blocks is located near or to the side of the contents of the tank, while in the case where the tank is integrated or installed in a vessel for transporting and / or storing cryogenic liquids, the lower surface or part of the foam blocks is positioned towards or on the outer side of the tank, that is, the lower surface or part of the foam blocks is particularly positioned towards the hull of the vessel.

[0063] It should therefore be understood that during the manufacture or production of the foam blocks, the concepts or terms "upper" or "lower" have no meaning, since the foam blocks have not yet been installed in the insulation panels of the tank. In other words, it is entirely possible to prepare the foam blocks according to the invention in such a way that, when they leave the production / production line, they acquire a position opposite to their final installation / assembly position in the insulation panels of the tank.

[0064] Advantageously, according to one feature of the invention, in the static state, said width L is between 1 and 12 mm, preferably between 1.5 and 6 mm.

[0065] Advantageously, the density of the foam block, preferably the fiber-reinforced foam block, is between 50 kg / m 3 Up to 250kg / m 3 Between, preferably between 90kg / m 3 Up to 210kg / m 3 It should be noted that for foam blocks used in self-supporting (type B, C) or semi-supporting (type A) tanks, the density of the fiber-reinforced foam blocks is preferably in the range of 30 kg / m 3 Up to 90kg / m 3 In the case of membrane type tanks, the preferred density range of the fiber reinforced foam block is between 90 kg / m 3 Up to 210kg / m 3 between.

[0066] According to one possibility provided by the invention, at least a portion of one of the abutting surfaces, preferably both abutting surfaces, comprises a composite layer or coating having a Young's modulus greater than the Young's modulus of the complementary shape or cross-section.

[0067] Advantageously, at least one foam block, preferably two foam blocks, comprise a polyurethane / polyisocyanurate foam consisting of pores for storing a gas, advantageously of low thermal conductivity, wherein advantageously at least 60%, preferably at least 80%, of said pores for storing the gas have a shape elongated or stretched along an axis parallel to an axis defined by a straight line perpendicular to the lower and / or upper surface of the foam block.

[0068] The expression "pores for storing gas" means that the polyurethane / polyisocyanurate foam has closed pores surrounding a gas, preferably a gas of low thermal conductivity, originating from a gas injected during the nucleation step of the reaction mixture or, directly or indirectly, from a chemical or physical expansion agent.

[0069] According to one embodiment, the expression "gas with (advantageously) low thermal conductivity" refers to a gas originating from a blowing agent, when the blowing agent is called a "chemical blowing agent", the above-mentioned gas is obtained by its chemical reaction, when the chemical blowing agent consists of water, the above-mentioned gas is usually carbon dioxide (CO2); or a gas originating from a physical blowing agent, such as nitrogen (N2), oxygen (O2), carbon dioxide, hydrocarbons, fluorochlorocarbons, hydrochlorocarbons, hydrofluorocarbons, hydrofluorochlorocarbons and mixtures thereof, and the corresponding alkyl ethers. Physical blowing agents such as molecular nitrogen N2, oxygen O2 or CO2 are in gaseous form. For example, these gases are dispersed or dissolved in a liquid copolymer using a static mixer under high pressure. When the system is depressurized, the nucleation and growth of bubbles produce a porous structure.

[0070] An elongated or stretched shape may be defined as a shape that is extended in length, ie one dimension of the porous structure (ie its length) is greater than the other dimensions (width and thickness).

[0071] Advantageously, the fiber-reinforced foam block according to the invention comprises between 0.1% and 5% by weight of an organic phosphorus flame retardant, advantageously triethyl phosphate (TEP), tris(2-chloropropyl) phosphate (TCPP), tris(1,3-dichloroisopropyl) phosphate (TDCP), tris(2-chloroethyl) phosphate or tris(2,3-dibromopropyl) phosphate, or mixtures thereof, or an inorganic flame retardant type, advantageously red phosphorus, expandable graphite, alumina hydrate, antimony trioxide, arsenic oxide, ammonium polyphosphate, calcium sulfate or a cyanuric acid derivative, or mixtures thereof.

[0072] The invention also relates to a sealed and heat-insulated tank integrated in a supporting structure, the tank consisting of the following tanks:

[0073] a tank integrated in a supporting structure, the supporting structure comprising a sealed thermally insulated tank comprising at least one sealed metal membrane consisting of a plurality of metal strips or plates which may include corrugations and a thermally insulating plate comprising at least one thermally insulating barrier adjacent to the membrane, or

[0074] - A type A, B or C tank as defined in the IGC Code, said type A, B or C tank comprising at least one insulating panel.

[0075] The tank according to the invention is characterised in that the insulation panel comprises an assembly of at least two foam blocks as briefly described above.

[0076] The expression "IGC Code" refers to the "International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk" which is well known to those skilled in the art, such as the above-mentioned Type B and Type C tanks.

[0077] It is noted that the expression "membrane tank" may be used, in particular in the IGC Code, instead of the expression "integral tank" to denote the same category of tanks, in particular installed on tankers for the transport and / or storage of at least partially liquefied gases. "Membrane tanks" are integrated in the supporting structure, whereas tanks of type A, B or C are considered to be self-supporting or semi-supporting (in particular type A) tanks.

[0078] Finally, the present invention also relates to a ship for transporting cold liquid products, the ship comprising at least one hull and a sealed and insulated liquid tank as briefly described above, when the liquid tank is a type A, B or C liquid tank defined according to the IGC Rules, the sealed and insulated liquid tank is placed in the hull or installed on the ship.

[0079] Furthermore, the present invention relates to an onshore or offshore storage tank for storing liquefied gas, said tank comprising at least one outer shell, preferably made of concrete or the like, and a sealed and insulated tank as briefly described above, said at least one outer shell being arranged in said outer shell. Such storage tanks, known as offshore tanks, are usually referred to as "GBS", which stands for "Global Base Storage".

[0080] Advantageously, in the case where the tank consists of a tank integrated in a supporting structure (membrane-type tank), such a vessel comprises at least one sealed and insulated tank as described above, said tank comprising two continuous sealing barriers, one being a main sealing barrier in contact with the product contained in the tank, and the other being a secondary sealing barrier arranged between the main sealing barrier and the supporting structure, the secondary sealing barrier preferably comprising at least a portion of the wall of the vessel, these two sealing barriers alternating with two insulating barriers or a single insulating barrier arranged between the main sealing barrier and the supporting structure.

[0081] As mentioned above, in a structure with two insulating barriers, the assembly according to the invention is intended to be applied in particular to the second insulating barrier and, of course, in the case of a single insulating barrier, the invention is intended to be applied to this single insulating barrier.

[0082] According to the rules of the International Maritime Organization (IMO), such tanks are usually called integral tanks, such as NO tanks, which include the following types: NO 、NO 、NO or NO 96 , or MARK 、MARK Flex+ or Flex.

[0083] Preferably, the membrane type tank or the A, B or C type tank contains liquefied natural gas (GNL) or liquefied gas (GL).

[0084] The present invention also relates to a transfer system for transferring cold liquid products, the system comprising a vessel as described above, an insulated transfer pipeline and a pump, wherein the insulated transfer pipeline is arranged to connect the liquid tank installed in the hull of the vessel to a floating or onshore storage unit, and the pump is used to pump the flow of cold liquid product from the floating or onshore storage unit to the vessel or from the vessel to the floating or onshore storage unit through the insulated transfer pipeline.

[0085] The invention also relates to a method for loading or unloading a vessel as described above, wherein a cold liquid product is transferred from a floating or onshore storage unit to the vessel or from the vessel to the floating or onshore storage unit via the insulated transfer pipeline.

[0086] The present invention also relates to a method for preparing an assembly of at least two polymer foam blocks of the above-mentioned insulation board of the sealed insulation tank, wherein the polymer foam is preferably a polyurethane / polyisocyanurate foam, characterized in that the method comprises the following steps:

[0087] a) mixing the chemical components required to obtain a foam, preferably a polyurethane / polyisocyanurate foam, comprising a reagent for obtaining the foam, optionally at least one reaction catalyst, optionally at least one emulsifier, and at least one blowing agent,

[0088] c) forming the foam and expanding the foam,

[0089] wherein the expansion of the foam is physically limited by the walls of a closed double belt laminator, preferably the walls of the double belt laminator forming a tunnel of rectangular or square cross-section, whereby the foam expands to obtain one of the foam blocks of the assembly,

[0090] Characterized in that the profile of at least one wall of the double-belt laminator is used to form a complementary shape or cross-section on a surface of the foam block, called an "adjacent" surface, and the "adjacent" surface of the foam block is used to be positioned adjacent to an "adjacent" surface of another block, which includes a shape or cross-section complementary to that of the foam block, so that when the two adjacent blocks are in operation, or when the two relative upper and lower surfaces of the two adjacent blocks have a temperature difference of at least 40°C, preferably at least 80°C, the minimum width L of the closed portion is reduced by at least 15%.

[0091] It is noted here that in the case of preparing an assembly of two polymer foam blocks, the present invention is intended to include the use of a double belt laminator (DBL), but it is conceivable that the two polymer foam blocks are obtained by free expansion, although in this case it is necessary to cut the foam blocks on one or more free expansion surfaces after preparing / obtaining the foam blocks.

[0092] Unlike the embodiments according to the invention prepared using a DBL, the fiber-reinforced polyurethane / polyisocyanurate foam is prepared by "free expansion", wherein the expansion of the fiber-reinforced foam is not restricted on at least one side or at least one expansion surface, so that the expansion of the fiber-reinforced foam is free on this side or surface, unlike the mold that defines the volume of the finished product. Typically, free expansion is achieved by omitting the (top) cover, while the side walls are used to prevent the foam from overflowing at the sides, and the foam naturally expands upwards, usually beyond the upper ends of these side walls.

[0093] Therefore, after the free expansion step of the fiber-reinforced polyurethane / polyisocyanurate foam, the fiber-reinforced foam must be cut, usually at the upper surface of the fiber-reinforced foam.

[0094] Preferably, the method according to the present invention comprises a step b) between steps a) and c), said step b) comprising an impregnation step: impregnating a plurality of fiber reinforcements by a gravity flow of said chemical component mixture, said fiber reinforcements being arranged in a stack, in which the fiber reinforcements extend substantially in a direction perpendicular to the direction of said gravity flow.

[0095] The expression "the fiber reinforcements extend substantially in a direction perpendicular to the direction of gravity flow of the chemical component mixture" means that during the impregnation step b), these fiber reinforcements are located in the form of a low-thickness layer in a plane perpendicular to the flow direction of the component mixture. Figure 3 As shown, a plurality of fiber reinforcements having a minimum width L and arranged in a stack are conveyed in a longitudinal direction l, while a chemical component mixture is deposited from a dispenser onto the fiber reinforcements, thereby obtaining / realizing a gravity flow of the chemical component mixture. In other words, the chemical component mixture, which may be under pressure and leaves the dispenser, falls on the stacked fiber layers at least under the effect of its own weight, thereby impregnating the fiber reinforcements from the upper layer to the lower layer.

[0096] As used hereinafter, the "cream time" is the time required, starting from the mixing of the chemical components, for the chemical components to start polymerizing and for the component mixture to start expanding and crosslinking in step c) (= formation of the fiber-reinforced PUR / PIR foam). This cream time is well known to the person skilled in the art. In other words, the cream time is the time after the mixing of the chemical components at room temperature until the mixture turns white due to the nucleation of gas bubbles (pores storing gas) and the expansion of the foam. The cream time can be determined by visual inspection or by using an ultrasonic sensor, which detects the thickness change reflecting the foam formation.

[0097] Advantageously, the fiber reinforcement has a variable fiber density and has a concentration or density of reinforcement in the region of the joining element such that the fiber density in this region is within a range of the average fiber density T of the finished foam block. f 1.2 to 3 times of the f To 2T f between.

[0098] In addition or as an alternative not shown in the drawings, at least a portion of the adjacent surface of the foam block (preferably at least a portion of the surface with complementary shape or cross-section) has a thin skin, in other words, its outer surface is mechanically attached or combined with a coating or layer, the material of which is another material with resistance to mechanical stress, which material, for example, has increased resistance to shear forces in particular, or has adhesion and anti-friction properties when two identical surfaces are in contact with each other. It is also conceivable that the coating or layer extends from one adjacent face of the block to another adjacent face. In this case, the coating or layer is continuous and at least partially covers the lower surface of the block 20 or 21. The coating or layer can be composed of a composite material, for example, composed of a glass fiber reinforced plastic with a thickness between 2 and 6 millimeters (mm).

[0099] Therefore, when two adjacent insulation panels move away from or separate from each other due to the cooling of the liquid tank and each polymer foam block shrinks as a result, when the initial width L (in a static state) is lower or smaller than the shrinkage phenomenon of the polymer block when the liquid tank is cooled, the complementary shape or cross-section of each adjacent block will contact its relative shape or cross-section to jointly form a joining component that resists such separation; from the structural perspective of the polymer foam block, the more reliable and safe the resistance to such separation, the better the mechanical strength performance (especially shear strength and tensile strength) of such shape or cross-section.

[0100] The use of chemical foaming agents in the compositions according to the invention can be combined with the use of physical expansion agents. In this case, the physical expansion agent is preferably mixed with the foamable (co)polymer composition in liquid or supercritical form and subsequently converted into the gas phase during the PUR / PIR foam expansion step.

[0101] Chemical foaming agents and physical foaming agents are well known to those skilled in the art, who can select a suitable amount of one or the other depending on the desired PUR / PIR foam.

[0102] A polyol is any carbon structure containing at least two OH groups.

[0103] Since whether PUR, PIR or PUR-PIR foam is obtained depends on the isocyanate / polyol ratio, PUR, PIR or PUR-PIR foam will be obtained according to this ratio. When the ratio between the polyol component and the isocyanate component is:

[0104] - Between 1:1 and 1:1.3, PUR polyurethane foam is obtained,

[0105] - Between 1:1.3 and 1:1.8, PUR-PIR polyurethane foam is obtained,

[0106] - Between 1:1.8 and 1:2.8, PIR polyurethane foam is obtained.

[0107] Polyisocyanates suitable for forming PUR, PIR and PUR-PIR foams are known to those skilled in the art and include, for example, aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, aliphatic aromatic polyisocyanates and mixtures thereof, advantageously aromatic polyisocyanates.

[0108] Examples of suitable polyisocyanates within the scope of the present invention include aromatic isocyanates such as the 4,4'-isomer, 2,4'-isomer and 2,2'-isomer of diphenylmethane diisocyanate (MDI), any compounds obtained by polymerization of these isomers, toluene-2,4- and -2,6-diisocyanate (TDI), m-phenylenediisocyanate and p-phenylene diisocyanate. diisocyanate), naphthalene-1,5-diisocyanate; aliphatic isocyanates, aliphatic cycloisocyanates, aliphatic aromatic isocyanates, such as 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,4-cyclohexane diisocyanate (CHDI), bis(isocyanomethyl)cyclohexane (H6XDI, DDI) and tetramethyl meta-xylylene diisocyanate (TMXDI). Any mixture of these diisocyanates can also be used. Advantageously, the polyisocyanate is the 4,4'-isomer, 2,4'-isomer and 2,2'-isomer of diphenylmethane diisocyanate (MDI).

[0109] Typically, during the formation of PUR foams, PIR foams or PUR-PIR foams, it is known practice to add a reaction catalyst to the mixture comprising polyols, polyisocyanates and blowing agents, which catalyst may be selected, for example, from tertiary amines (such as N,N-dimethylcyclohexylamine or N,N-dimethylbenzylamine) or organometallic compounds based on bismuth, potassium or tin.

[0110] According to a preferred embodiment of the invention, advantageously, the position of the tunnel walls of the double belt laminator (DBL) is defined so that the restriction of the expansion of the fiber reinforced polyurethane / polyisocyanurate foam results in a volume of the fiber reinforced polyurethane / polyisocyanurate foam at the outlet of the double belt laminator being between 85% and 99%, preferably between 90% and 99%, of the expanded volume of the same fiber reinforced polyurethane / polyisocyanurate foam when the expansion occurs freely (without restriction by such double belt laminator walls). In this case, a foam is obtained having pores of oval shape, preferably oriented along the axis E, so that the foam has advantageous properties of resistance to crushing along this direction E (measured according to ISO844 standard), and this advantageous property is combined with the properties already described in a plane perpendicular to this axis E. The applicant has carried out tests and experiments to determine the above broad preferred range, but for the sake of clarity and conciseness, it is not described here.

[0111] By means of the above-mentioned specific parameter setting of the expansion constraint of the fiber-reinforced PUR / PIR foam in the DBL, a fiber-reinforced PUR / PIR foam block is obtained, in which at least 60%, usually more than 80%, even more than 90% of the pores for storing gas with low thermal conductivity extend longitudinally along an axis parallel to the axis of thickness E of the foam block, and at the same time, in addition to specific choices related to the properties of the fiber reinforcement and the viscosity of the chemical component mixture, the specific parameter setting also contributes to the optimal uniformity of the fiber-reinforced foam block. These two characteristics (orientation of the pores and the fiber content T in the block outside one or more regions constituting the joint member) are f The uniformity of the thickness E (compressive strength) makes it possible to obtain fiber-reinforced foam blocks with excellent mechanical properties in the thickness E (compressive strength) and in the plane perpendicular to the thickness direction (tensile strength and relatively low thermal shrinkage coefficient).

[0112] As previously mentioned, an elongated or stretched shape may be defined as a shape that is extended in length, ie one dimension of the microporous structure (ie its length) is greater than the other dimensions (width and thickness).

[0113] According to a possibility provided by the invention (not shown in the drawings), after the step of impregnating the fiber reinforcement, a pressure application system (for example, a roller system that can be called a "nip roller") is applied to the mixture of the components and at least the foaming agent for impregnating the fibers, wherein the pressure application system is used to apply pressure to the upper surface of the assembly comprising the mixture and the fibers. This pressure system, on the one hand, makes the upper surface of the assembly flat, and, by the pressure applied to the assembly, helps to promote the impregnation of the fibers in the mixture. The pressure system can be composed of a single roller or a double roller, and the relative position of the pressure system above the liquid assembly and, where applicable, below the foam support is adjusted to force the liquid assembly to spread completely and evenly. In this way, an equal amount of liquid assembly can be obtained at any point in the section defined by the spacing between the two rollers or between the upper roller and the conveyor belt. In other words, the main purpose of the pressure system is to supplement the liquid distribution device, because the pressure system helps to make the liquid assembly uniform in thickness / width before most of its expansion.

[0114] Preferably, at ambient temperature (25°C) and atmospheric pressure (1015mPa), the dynamic viscosity η of the component mixture is between 30mPa.s and 3000mPa.s (or between 0.03Pa.s and 3Pa.s), preferably between 50mPa.s and 1500mPa.s (or between 0.05Pa.s and 1.5Pa.s).

[0115] The dynamic viscosity of the component mixture can be determined using a viscometer (for example of the Brookfield type) or a rheometer (for example according to the ISO 2555 standard).

[0116] In general, it should be understood that the subject matter of the present invention uses materials / products that are available or usable on the market so that the properties of these materials / products, especially those related to their density or viscosity (dynamic), are available within the specifications related to the materials / products in question.

[0117] Preferably, the fibers (fiber reinforcement) are arranged over the entire width B of the conveyor belt and step b), i.e. impregnating the fibers with a mixture of components and blowing agent, is performed simultaneously over the entire width B using a controlled liquid distributor to obtain a fiber-reinforced polyurethane / polyisocyanurate foam.

[0118] The term "simultaneously" means that the liquid mixture (reactants and at least blowing agent) reaches the fibers simultaneously along a cross section of width L, so that the impregnation of each fiber reinforcement starts or occurs simultaneously or at the same speed through the thickness (or height) of the foam block and across the same width cross section.

[0119] Advantageously, the blowing agent consists of a physical and / or chemical expansion agent, preferably a combination of these two types.

[0120] Preferably, the physical swelling agent is selected from alkanes and cycloalkanes having at least 4 carbon atoms, dialkyl ethers, esters, ketones, acetals, fluoroalkanes, fluoroolefins having 1 to 8 carbon atoms in the alkyl chain and tetraalkylsilanes having 1 to 3 carbon atoms (especially tetramethylsilane), or mixtures thereof.

[0121] In this case, taking compounds as an example, the compounds can be propane, n-butane, isobutane, cyclobutane, n-pentane, isopentane, cyclopentane, cyclohexane, dimethyl ether, methyl ethyl ether, methyl butyl ether, methyl formate, acetone and fluoroalkanes; the fluoroalkanes selected are alkanes that do not damage the ozone layer, such as trifluoropropane, 1,1,1,2-tetrafluoroethane, difluoroethane and heptafluoropropane. Examples of fluorinated olefins include 1-chloro-3,3,3-trifluoropropene, 1,1,1,4,4,4-hexafluorobutene (e.g. HFO FEA1100 sold by DuPont).

[0122] According to a preferred embodiment of the present invention, the selected physical expansion agent is 1,1,1,3,3-pentafluoropropane or HFC-245fa (sold by Honeywell), 1,1,1,3,3-pentafluorobutane or 365MFC (for example, Sollkane sold by Solvay). 365MFC), 2,3,3,3-tetrafluoroprop-1-ene, 1,1,1,2,3,3,3-heptafluoropropane (also designated internationally as HFC-227ea, sold for example by DuPont), 1,1,1,4,4,4-hexafluorobutene (sold for example by DuPont as HFOFEA1100), trans-1-chloro-3,3,3-trifluoropropene (Solstice LBA from Honeywell) or mixtures thereof.

[0123] Advantageously, the chemical swelling agent consists of water.

[0124] Advantageously, in step a) of mixing the chemical components, a nucleating gas is incorporated into at least one polyol compound, preferably using a static / dynamic mixer at a pressure between 20 and 250 bar, the nucleating gas representing 0% to 50% by volume of the polyol, preferably 0.05% to 20% by volume of the polyol.

[0125] Preferably, during step a) of mixing the chemical components, the temperature of each reagent for obtaining the polyurethane / polyisocyanurate is between 10°C and 40°C, preferably between 15°C and 30°C.

[0126] Preferably, according to a preferred embodiment of the present invention, the final mixing of the polyol stream, isocyanate stream and / or blowing agent stream is carried out in a mixing tube at low pressure (<20 bar) or high pressure (>50 bar) by a dynamic or static mixer.

[0127] According to one possibility provided by the present invention, in step a), an organic phosphorus flame retardant or an inorganic flame retardant is also added to the mixture, the organic phosphorus flame retardant is preferably triethyl phosphate (TEP), tris(2-chloropropyl) phosphate (TCPP), tris(1,3-dichloroisopropyl) phosphate (TDCP), tris(2-chloroethyl) phosphate or tris(2,3-dibromopropyl) phosphate, or a mixture thereof, and the inorganic flame retardant is advantageously red phosphorus, expandable graphite, alumina hydrate, antimony trioxide, arsenic oxide, ammonium polyphosphate, calcium sulfate or a cyanuric acid derivative, or a mixture thereof.

[0128] It is also conceivable to use diethoxyethyl phthalate (DEEP), triethyl phosphate (TEP), dimethylpyrazole phosphate (DMPP) or toluene diphenyl phosphate (CDP) as flame retardants.

[0129] When present in the composition, the flame retardant is present in an amount between 0.01% and 25% by weight of the PUR / PIR foam. BRIEF DESCRIPTION OF THE DRAWINGS

[0130] The following description is provided for illustrative and non-limiting purposes only with reference to the accompanying drawings, in which:

[0131] [ Figure 1 ] shows an insulation panel forming a first insulation layer of an insulation board of a sealed insulation tank according to the prior art or a barrier installed on an insulation panel forming a second insulation layer.

[0132] [ Figure 2 ] is a cross-sectional view showing a portion of another insulation panel of a sealed insulation tank according to the prior art.

[0133] [ Figure 3 ] is a schematic diagram showing the various steps in a method for producing a fiber-reinforced PUR / PIR foam block of a component according to the present invention.

[0134] [ Figure 4 ] is a schematic diagram of an embodiment of a foam block whose complementary shape or cross-section is used to form a joining member with another foam block.

[0135] [ Figure 5 ] is a schematic diagram of an embodiment of an assembly of two polymer foam blocks according to the present invention.

[0136] [ Figure 6 ] is a schematic cross-sectional view showing an embodiment of a joining member of an assembly of two polymer foam blocks according to the present invention.

[0137] [ Figure 7 ] is another schematic cross-sectional view showing an embodiment of a joining member of an assembly of two polymer foam blocks according to the present invention.

[0138] [ Figure 8 ] is a cross-sectional view of a tank for a liquefied gas carrier and a dock for loading / unloading the tank, in which a Figures 4 to 7 Two heat shield assemblies of the type shown. DETAILED DESCRIPTION

[0139] Figure 1 and Figure 2 Intended to illustrate the use of polymer foam blocks in insulation panels of sealed insulated tanks according to the prior art. In both figures, the polymer foam blocks do not have substantially the same shape and in fact are used for integration in insulation panels of sealed insulated tanks of different types.

[0140] However, it should be noted that the present invention relates to an assembly of two polymer foam blocks having specific characteristics compared to the prior art, but the present invention does not intend to modify other technical aspects of the insulation board of the sealed insulating liquid tank, unless it is possible to adapt the other technical aspects of the insulation board to the new features of the assembly of polymer foam blocks, in particular by removing all or some of the bolts 1 used to attach the foam blocks.

[0141] Figure 1 Sixteen polymer foam blocks 2 forming the primary insulation layer 3 are shown, while a single foam block 4 forms the secondary insulation layer 5. Wooden boards 6 made of plywood are attached to the polymer foam blocks 2 forming the primary insulation layer 3 by adhesive bonding, and anchor strips 7 for anchoring the primary sealing membrane 8 are fixed to some of the wooden boards, wherein the primary sealing membrane 8 is only Figure 2 China-Israel MARK III It can be seen in the form of a bellows sealing membrane.

[0142] Below the insulating blocks 2 forming the primary layer 3 is a secondary sealing membrane 9 also known as a rigid secondary barrier (RSB). Figure 1 In the case of the insulation board shown, the secondary sealing membrane is fixed by adhesive bonding to the polymer foam block 4 forming the secondary insulation layer 5. Finally, a wooden board 13 made of plywood is fixed under the secondary layer 5.

[0143] Figure 2 Shown are mastic strips 14 and bolts 1 which are typically used to attach and secure the secondary layer 5 or insulation board and thereby the sealed insulation tank to the surface of the container 15. Figure 8 As shown, these surfaces of the container 15 may in particular comprise the walls of a ship, or the walls of a fixed storage tank, for example of the Gravity Based Structure (GBS) type, or the walls of a mobile storage tank on land.

[0144] Likewise, the present invention does not intend to modify the conventional elements of a sealed insulated tank other than the polymer foam blocks, but of course the present invention may omit one or more elements of such a tank, or involve modifications to one or more of the elements in order to provide for the function of closing a channel separating two blocks or for the function of retaining or joining adjacent polymer foam blocks.

[0145] about Figure 3The preparation of fiber-reinforced PUR / PIR is preferably carried out in the presence of a catalyst, so that the isocyanate-polyol reaction can be promoted. For example, such compounds are described in Chapter 3.4.1 of the prior art document entitled "Kunststoffhandbuch, volume 7, Polyurethane", 3rd edition, published by Carl Hanser in 1993. These compounds include amine-based catalysts and catalysts based on organic compounds.

[0146] Preferably, the preparation of the fiber-reinforced PUR / PIR foam block according to the invention is carried out in the presence of one or more stabilizers, which are used to promote the formation of a regular porous structure during the foam formation process. These compounds are well known to those skilled in the art and, as an example, may involve foam stabilizers including silicones (such as siloxane-oxyalkylene copolymers) and other organopolysiloxanes.

[0147] Those skilled in the art will appreciate that, depending on the agent in question, the amount of stabilizer used is between 0.5% and 4% by weight of the PUR / PIR foam.

[0148] According to one possibility provided by the invention, in step a) of the preparation method, the mixture of chemical components may include a plasticizer (e.g. a polybasic plasticizer, preferably a dibasic plasticizer), an ester, a monohydric carboxylic acid, or consist of a polymeric plasticizer, such as a polyester of adipic acid, sebacic acid and / or phthalic acid. Depending on the reagent used, it will be understood by those skilled in the art that the amount of plasticizer envisaged is generally between 0.05% and 7.5% by weight of the polyurethane / polyisocyanurate foam.

[0149] It is also conceivable to use organic and / or inorganic fillers in the mixture of chemical components, in particular reinforcing fillers, such as siliceous minerals, metal oxides (e.g. kaolin, titanium oxides or iron oxides) and / or metal salts, etc. If these fillers are present in the mixture, the amount of these fillers is generally between 0.5% and 15% by weight of the PUR / PIR foam.

[0150] It should be noted that the present invention is not intended to add technical teachings on the formation of PUR / PIR foams in terms of the nature of the basic chemical components and the optional functional agents and their respective amounts. Based on the specific choice of the characteristics of the fiber reinforcements (especially the fiber density in the different fiber reinforcements and very specifically the fiber density in the complementary shape or section for each foam block) and the equally specific choice of the foam used for the impregnation of said reinforcements, the person skilled in the art will know how to obtain the different types of fiber-reinforced PUR / PIR foams involved in the present preparation.

[0151] like Figure 3 As shown, a plurality of fiber reinforcements 10 are spread out and aligned parallel to one another on or above a conveyor belt 11, which is used to transport these reinforcements 10 and the components for forming the PUR / PIR foam. Specifically, within the framework of the preferred mode of production of the fiber-reinforced foam block of the invention, the impregnation of the fiber reinforcements 10 is carried out by gravity, that is, a mixture 12 of chemical components, one or more blowing agents and any other functional agents for obtaining the PUR / PIR foam is poured directly onto the fibers 10 from a liquid dispenser located above the fiber reinforcements 10.

[0152] Therefore, whether the fiber reinforcement 10 is a plurality of mats or a plurality of fabrics, the mixture 12 must impregnate all layers of the fiber reinforcement 10 in a very uniform manner for a cream time t c , so that the PUR / PIR foam begins to expand after or at the earliest when the fiber reinforcement 10 is fully properly impregnated with the mixture 12. In this way, the expansion of the PUR / PIR foam is achieved while maintaining a perfectly specific distribution of the fibers 10 in the volume of the PUR / PIR foam block, thereby obtaining the desired fiber density gradient.

[0153] In the context of the present invention, the cream time of the components of the mixture 12 for forming the PUR / PIR foam is known to a person skilled in the art and is selected so that the conveyor belt 11 conveys the assembly formed by the mixture 12 of components, blowing agent and fibers 10, for example to a double-belt laminator (not shown in the drawings) when the expansion of the foam has just begun. In other words, the expansion of the PUR / PIR foam is thus ended in the double-belt laminator.

[0154] In this embodiment with a double belt laminator (DBL), a pressure system using one or two rollers is optionally arranged before the double belt laminator, i.e., between the impregnation zone of the mixture on the fibers and the double belt laminator. In the case of using a DBL, the expansion of the foam volume takes place in the laminator when the expansion volume of the foam reaches between 30% and 60% of the expansion volume of the same foam when it is freely expanded (i.e., without any restrictions). In this way, the double belt laminator will be able to limit the expansion of the PUR / PIR foam during its second expansion phase when the PUR / PIR foam is close to or relatively close to its maximum expansion, i.e., when the expansion of the PUR / PIR foam brings the foam close to all walls of the double belt laminator (these walls form a tunnel of rectangular or square cross-section). Depending on the different ways of expressing the specific choices involved in the preparation, the gel point of the mixture of components, that is, the moment when the polymerization of the mixture of components reaches at least 60%, in other words, the moment when the mixture has expanded to 70% to 80% of its maximum volume, must occur in the double-belt laminator and may occur in the second half of the length of the double-belt laminator (that is, closer to the exit of the laminator than to the entrance of the laminator).

[0155] The function of distributing the mixture 12 of chemical components and foaming agent simultaneously over the entire width B of the fiber reinforcement 10 (corresponding to the width of the conveyor belt 11) can be ensured by a controlled liquid distributor not shown in the drawings. Such a distributor comprises a channel for taking the assembly formed by the mixture of chemical components and at least foaming agent from a reservoir forming a reagent mixer, in which, on the one hand, all chemical components and foaming agent are mixed, and on the other hand, in particular the nucleation or even heating of the above-mentioned mixture occurs in the reagent mixer. The liquid assembly formed by the mixture 12 of chemical components and foaming agent is then distributed under pressure in two channels, which extend transversely so as to terminate respectively at two identical distribution plates 18, which extend across the width B (the length of each distribution plate is approximately equal to L / 2), and which comprise a plurality of nozzles for making the mixture 12 flow onto the fiber reinforcement 10. These flow nozzles can consist of orifices of calibrated cross-sections with a predetermined length. Therefore, the length of these flow nozzles is determined so that the liquid flows out through all the nozzles at the same flow rate, so that the impregnation of the fiber reinforcement 10 occurs at the same time or simultaneously on the section of the width B of the fiber reinforcement 10, and so that the surface density of the deposited liquid corresponding to each nozzle is equal. In this way, a section of the width B of the fiber 10 is taken and the fiber 10 is impregnated simultaneously, so that the impregnation of the layer of fiber 10 by the mixture 12 is carried out in the same way at all points on this section, which helps to obtain a fiber-reinforced foam block at the output of the double-belt laminator in which, when the mixture 12 is poured by gravity, the local fiber density corresponds exactly to the fiber density of each layer in the stack of fiber reinforcements.

[0156] Cream time t of PUR / PIR foam c An important aspect of achieving good impregnation of the fiber reinforcement 10 previously lies in the choice of a specific viscosity of the liquid (consisting of a mixture 12 of chemical components and blowing agent), which is linked to the specific properties of the respective fiber reinforcement, which vary according to the fiber density. The selected viscosity range together with the penetration properties of the fiber reinforcement must allow the liquid to penetrate well into the first layer of fibers 10 in order to reach the subsequent layers until the last layer (the lower layer of fibers 10, i.e. the layer located at the bottom of the stack of fiber reinforcements) is reached, so that the impregnation time ti of the fibers 10 is achieved within a time range determined by the chemical components, which corresponds approximately to but is always less than the milky time t cThe viscosity of the mixture 12 of components is selected, for example, by heating, addition of plasticizers and / or more or less pronounced nucleation, so that the impregnation of all fibers 10 in a cross section of width B with the mixture 12 of chemical components and blowing agent occurs before the cream time, i.e. before or just before the start of expansion of the PUR / PIR foam.

[0157] The fiber-reinforced foam blocks are intended for use in very specific environments and therefore must guarantee specific mechanical and thermal properties. Therefore, the fiber-reinforced foam blocks obtained by the above-mentioned preparation usually form part of an insulation board, i.e. Figure 4 or Figure 5 In the example used in, the fiber reinforced foam blocks are located in the upper or primary plate and / or the lower or secondary plate of such an insulating plate of a tank 71 for receiving a very cold liquid (such as GNL or GPL). For example, such a tank 71 can be installed in a tank on the ground, a floating barge, etc. (such as a floating storage regasification unit (FSRU), or a floating liquefied natural gas (FLNG)), or even installed on a ship used to transport the liquid fuel between two ports, such as a liquefied gas carrier.

[0158] Figure 4 An embodiment of a polymer foam block 20 is shown, which is intended to form an assembly according to the invention together with another polymer foam block 21. It can be seen that the foam block 20 includes L-shaped ears or protrusions 24, 25 on both side surfaces 22, 23, the L-shaped ears or protrusions 24, 25 on each side surface 22, 23 of the block 20 being reversed or opposite so that these ears or protrusions 24 or 25 cooperate with the ears or protrusions 24 or 25 on the adjacent foam block 21, as shown in FIG. Figure 6 or Figure 7 shown.

[0159] One or more vertical portions 26, 27 (i.e. portions extending through the thickness of the foam blocks 20, 21) may be provided, which are at least partially filled with expandable thermal insulation 28, such as glass wool, to prevent any harmful thermal phenomena. These elements 28 and 31 may be fixed by adhesive bonding, stapling or simply positioned using a third element so as to be subsequently held in place by pressure.

[0160] It is also important to note that the ducts or channels 30 do not extend throughout the entire height or thickness of the foam blocks 20, 21 and are Figure 5 and Figure 6 In the embodiment shown, the vertical portions 26, 27 of the ducts or channels 30 extend at most over 2 / 3 of the height or thickness of the foam blocks. Thus, the complementary shapes or cross-sections 24, 25 of the adjacent foam blocks 20, 21 ensure, on the one hand, the engagement, retention or maintenance of the function between the blocks when the tank 71 is in operation (i.e. the cold liquid load is at least 20% of the maximum storage volume of the tank), and on the other hand, avoid any undesirable thermal phenomena, such as thermosiphoning.

[0161] The closed portion or portions 60 of the ducts or channels 30 most likely to come into contact when adjacent polymer foam blocks contract may advantageously include a flexible material 31 having a high plasticity in order to absorb the mechanical stresses associated with the tension caused by the approach of adjacent foam blocks 20, 21. The portions of the ducts or channels 30 most likely to move away from each other when adjacent polymer foam blocks 20, 21 contract advantageously have an expandable insulation material 28 as previously described, or even the same flexible material 31 as described above, which is capable of elastically and / or plastically deforming while maintaining a mechanical connection between the two blocks 20 and 21, thereby making it possible to form a closed wall.

[0162] exist Figure 6 In the embodiment shown, one or more closed portions 60 of the channel or duct 30 include an inclined plane, the length of which is at least 1 / 3 of the height or thickness of the block 20 or 21. Due to the large length of the closed portion 60, if the surfaces come into contact when the blocks 20, 21 are contracted, the closed portion 60 can be used as a joining member, making it possible to mechanically connect two adjacent blocks 20, 21 and absorb forces that tend to cause the blocks 20, 21 to buckle or bend.

[0163] Figure 7 An alternative embodiment of a joining member according to the invention is shown. Figures 4 to 7 Unlike the embodiment of the invention, the closing portion 60 or the engaging member (if applicable) does not have a point of symmetry with respect to the two blocks 20, 21. Specifically, in this embodiment, the closing portion 60 comes from a hook tongue 33, which starts from the side surface 23 of the block 21 and extends in a first proximal portion 34 to an end portion 35, wherein the first proximal portion 34 is thinner - its thickness or height is reduced - and widens in a second section, the end portion 35 is wider - its thickness or height is at least twice the thickness or height of the proximal portion 34 - and the end portion 35 is longer, its length exceeding twice the length of the proximal portion 34. The closing portion 60 has a shape or cross-section complementary to that of the hook tongue 33 on the other adjacent block 20, the hook tongue 33 consisting of a compact hook foot 36. Figures 5 to 7 Compared to the embodiment of the embodiment, this asymmetry between the two complementary shapes or sections 33, 36 has the following advantages: it enables a compact shape or section 36 to be produced, which can better resist the movement away from the other foam block 21 when the two surfaces of the two blocks 20, 21 are in contact at the closed part 60, for example when the position of the block 20 or 21 in the liquid tank makes it easier to shrink.

[0164] Reference Figure 8 , a partially cut-away view of a liquefied gas carrier 70 shows a generally prismatic sealed and insulated tank 71 installed in a double hull 72 of the carrier. The wall of the tank 71 includes a primary sealing barrier, a secondary sealing barrier, and two insulating barriers, wherein the primary sealing barrier is used to contact the GNL contained in the tank, the secondary sealing barrier is arranged between the primary sealing barrier and the double hull 72 of the carrier, and the two insulating barriers are arranged between the primary sealing barrier and the secondary sealing barrier and between the secondary sealing barrier and the double hull 72, respectively.

[0165] In a manner known per se, the loading / unloading transfer pipe 73 arranged on the upper deck of the carrier can be connected by means of suitable connections to a marine or port terminal for transferring the GNL cargo from or to the tanks 71 .

[0166] Figure 8 An example of a marine terminal is shown, which includes 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, which includes a movable arm 74 and a tower 78 supporting the movable arm 74. The movable arm 74 carries a series of insulated flexible pipes 79, which can be connected to the loading / unloading transfer pipeline 73. The orientable movable arm 74 can be adjusted to accommodate liquefied gas carriers of all sizes. Connecting pipes (not shown) extend inside the tower 78. The loading and unloading station 75 enables the loading and unloading of liquefied gas carriers 70 from or to the onshore facility 77. The facility includes a tank 80 for storing liquefied gas and a connecting pipe 81 connected to the loading and unloading station 75 by an underwater pipeline 76. The underwater pipeline 76 enables the transfer of liquefied gas over long distances (eg 5 km) between the loading and unloading station 75 and the onshore facility 77, which enables the liquefied gas carrier 70 to be maintained at a long distance from the coast during loading and unloading operations.

[0167] Pumps on the carrier 70 and / or pumps installed on the onshore facility 77 and / or pumps installed on the loading and unloading station 75 are used to generate the pressure required to transfer the liquefied gas.

[0168] As mentioned above, the subject matter of the present invention, i.e. in this case a fiber-reinforced polyurethane / polyisocyanurate foam block, is not intended or applicable only to tanks integrated in supporting structures, but also to tanks of types A, B and C as defined in the IGC Rules in force on the date of filing of the present patent application, unless these tanks of types A, B and C are modified in a rather substantial manner, the subject matter of the present invention also applies to future editions of this specification, it being understood, moreover, that in the event of a modification of the IGC Rules, the fiber-reinforced PUR / PIR foam block according to the present invention may become applicable to other types of tanks.

[0169] Given below are some experiments and tests carried out by the applicant to enable an assessment of the subject matter of the invention and its scope, while it should be noted that many tests / experiments have been carried out and may be provided later if desired / necessary.

[0170] right Figure 6 and Figure 7 A large number of tests were carried out on actual-sized PUR / PIR foam blocks of the type shown, which were exposed to temperature conditions representative of their operating conditions, with the temperature difference between the upper and lower surfaces of the foam blocks being greater than 80°C (as is the case in a tank containing liquefied natural gas).

[0171] On average, it was observed that the minimum width L of the channel / duct at the closed portion 60 was reduced by more than 15%, in fact by more than 50%. In case the width L of the channel / duct at the closed portion 60 is initially small / low (about 1-3 millimeters (mm)), during use of the tank (= when the foam blocks 20, 21 are in operation), the blocks come into contact via the closed portion 60, which reinforces the mechanical stability of the block assembly and prevents bending / buckling.

[0172] Furthermore, it should be noted that the assembly according to the invention comprising two PUR / PIR foam blocks does not show any significant impairment of its properties in relation to the (very low) thermal conductivity.

[0173] [Table 1]

[0174]

[0175] Although the present invention has been described in conjunction with a number of specific embodiments, it is apparent that the present invention is not limited thereto and that the present invention includes all technical equivalents of the described components and their combinations if such technical equivalents fall within the scope of the present invention.

[0176] Use of the verb "comprise" or "include" and its conjugated forms does not exclude the presence of other contents or steps other than those stated in a claim.

[0177] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims

1. A sealed heat-insulating liquid tank (71), the sealed heat-insulating liquid tank (71) comprising the following liquid tanks: a tank integrated in a supporting structure, the supporting structure comprising a sealed thermally insulated tank comprising at least one sealed metal membrane consisting of a plurality of metal strips or metal plates comprising corrugations and a thermally insulating plate comprising at least one thermally insulating barrier adjacent to the membrane, or - a tank of type A, B or C as defined in the IGC Code, said tank comprising at least one insulating panel, characterised in that: The insulation board comprises an assembly of at least two polymer foam blocks of the insulation board sealing the insulation liquid tank (71), the density of the foam blocks having at least opposite upper and lower surfaces and side surfaces being 30 kg / m 3 Up to 300kg / m 3 The first foam block (20) and the second foam block (21) have surfaces called "adjacent" surfaces (22, 23), the first foam block (20) and the second foam block (21) are arranged adjacent to each other so that the adjacent surface (22) of the first foam block (20) and the adjacent surface (23) of the second foam block (21) form a channel or a pipe (30) between them, when the first foam block and the second foam block are in a static state, that is, when there is no obvious temperature difference between the two opposite upper and lower surfaces of the first foam block and the second foam block, the channel or the pipe is in the channel or the pipe The first foam block (20) and the second foam block (21) have a minimum width L on at least one portion thereof, which is called a closed portion; the adjacent surfaces (22, 23) of the first foam block (20) and the second foam block (21) have at least a shape or cross-section (24 or 25) that is substantially complementary to the shape or cross-section (24 or 25) of the other adjacent surface (22 or 23) of the first foam block (20) or the second foam block (21); when the first foam block and the second foam block are in operation, that is, when the two relative upper and lower surfaces of the first foam block and the second foam block have a temperature difference of at least 40°C, the width L of the closed portion is reduced by at least 15%.

2. The sealed thermal insulation tank (71) according to claim 1, wherein: The width L is reduced by at least 50%.

3. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: The channel or the conduit (30) has a non-linear path in the cross-sectional plane P.

4. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: In the working state, the minimum width L is equal to 0, so that the two adjacent blocks are in contact at least at the closed portion.

5. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: The closed portion comprises a material having a compressibility at least equal to 15%.

6. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: The substantially complementary shapes or cross-sections (24, 25) consist of a convex portion and a concave portion, respectively.

7. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: At least one foam block consists of a fiber-reinforced foam having an average fiber density T f Between 1% and 60% by weight of the fibers (10); the fibers (10) are composed of glass fibers, basalt fibers or hemp fibers.

8. The sealed thermal insulation tank (71) according to claim 7, wherein: The substantially complementary shape or cross-section has a greater average fiber density T f Fiber (10) density.

9. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: The channel or the duct comprises thermal insulation material.

10. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: The first foam block (20) and the second foam block (21) have a substantially parallelepiped or cubic shape.

11. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: In the static state, the width L is between 1 mm and 12 mm.

12. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: The density of the foam block is 50 kg / m 3 Up to 250kg / m 3 between.

13. The sealed thermal insulation tank (71) according to claim 1 or 2, wherein: At least a portion of one of the abutting surfaces (22 or 23) includes a composite layer or coating having a Young's modulus greater than the Young's modulus of the substantially complementary shape or cross-section.

14. The sealed thermal insulation tank (71) according to claim 1, wherein: The polymer foam is a polyurethane / polyisocyanurate foam.

15. The sealed thermal insulation tank (71) according to claim 1, wherein: When the first and second foam blocks are in operation, ie, when two opposite upper and lower surfaces of the first and second foam blocks have a temperature difference of at least 80° C., the width L of the closed portion decreases by at least 15%.

16. The sealed thermal insulation tank (71) according to claim 5, wherein: The closed portion comprises a material having a compressibility at least equal to 50%.

17. The sealed thermal insulation tank (71) according to claim 5, wherein: The closing part is composed of an elastomer.

18. The sealed thermal insulation tank (71) according to claim 17, wherein: The elastomer is glass wool or rock wool.

19. The sealed thermal insulation tank (71) according to claim 7, wherein: The first foam block (20) and the second foam block (21) are composed of fiber-reinforced foam.

20. The sealed thermal insulation tank (71) according to claim 7, wherein: The fibers (10) are long or continuous.

21. The sealed thermal insulation tank (71) according to claim 7, wherein: The fibers (10) are composed of glass fibers.

22. The sealed thermal insulation tank (71) according to claim 8, wherein: The substantially complementary shapes or cross-sections have a 1.2T f To 3T f The density of fibers (10) therebetween.

23. The sealed thermal insulation tank (71) according to claim 8, wherein: The substantially complementary shapes or cross-sections have a 1.4T f Up to 2T f The density of fibers (10) therebetween.

24. The sealed thermal insulation tank (71) according to claim 9, wherein: The heat insulating material is glass wool.

25. The sealed thermal insulation tank (71) according to claim 11, wherein: In the static state, the width L is between 1.5 mm and 6 mm.

26. The sealed thermal insulation tank (71) according to claim 12, wherein: The foam block is a fiber-reinforced foam block.

27. The sealed thermal insulation tank (71) according to claim 12, wherein: The density of the foam block is 90 kg / m 3 Up to 210kg / m 3 between.

28. The sealed thermal insulation tank (71) according to claim 13, wherein: At least a portion of the two abutting surfaces (22 and 23) comprises a composite layer or coating.

29. A ship (70) for transporting cold liquid products, the ship comprising at least one hull (72) and a sealed and insulated liquid tank (71) according to claim 13, when the sealed and insulated liquid tank (71) is a type A, B or C liquid tank defined according to the IGC rules, the sealed and insulated liquid tank is placed in the hull or installed on the ship (70).

30. A transfer system for transferring cold liquid products, the system comprising a vessel (70) according to claim 29, an insulated transfer pipeline (73, 76, 79, 81) and a pump, wherein the insulated transfer pipeline is configured to connect the sealed insulated liquid tank (71) installed in the hull of the vessel to a floating or onshore storage unit (77), and the pump is used to pump a flow of cold liquid product from the floating or onshore storage unit to the vessel (70) or from the vessel to the floating or onshore storage unit through the insulated transfer pipeline.

31. A method for loading or unloading a vessel (70) according to claim 29, wherein: The cold liquid product is transferred from a floating or onshore storage unit (77) to the vessel (70) or from the vessel to the floating or onshore storage unit via an insulated transfer pipeline (73, 76, 79, 81).

32. A method for producing an assembly of at least two polymer foam blocks of an insulation panel for a sealed insulation tank (71) according to any one of claims 1 to 28, characterized in that The method comprises the following steps: a) mixing the chemical components required to obtain the foam, said chemical components comprising a reagent for obtaining said foam and at least one blowing agent, c) forming the foam and expanding the foam, wherein the expansion of the foam is physically limited by the walls of a closed double belt laminator, whereby the foam expands to obtain one of the foam blocks of the assembly, Characterized in that the profile of at least one wall of the double-belt laminator is used to form a complementary shape or cross-section (24, 25) on a surface of the foam block, called an "adjacent" surface (22, 23), and the "adjacent" surface of the foam block is used to be positioned adjacent to an "adjacent" surface (22 or 23) of another block, which includes a shape or cross-section (24, 25) complementary to the foam block, so that when the two adjacent blocks are in operation, or when the two opposite upper and lower surfaces of the two adjacent blocks have a temperature difference of at least 40°C, the minimum width L of the closed portion is reduced by at least 15%.

33. The method for preparing an assembly of at least two polymer foam blocks of an insulation panel for a sealed insulating liquid tank according to claim 32 comprises a step b) between step a) and step c), wherein step b) comprises an impregnation step: impregnating a plurality of fiber (10) reinforcements by a gravity flow of a mixture of the chemical components, the fiber (10) reinforcements being arranged in a stack, in which the fiber (10) reinforcements extend substantially in a direction perpendicular to the direction of the gravity flow.

34. A method for preparing an assembly of at least two polymer foam blocks for use in insulating panels for sealing insulating tanks according to claim 32, wherein: The polymer foam is a polyurethane / polyisocyanurate foam.

35. A method for preparing an assembly of at least two polymer foam blocks for use in insulating panels for sealing insulating tanks according to claim 32, wherein: In step a), the foam is a polyurethane / polyisocyanurate foam.

36. A method for preparing an assembly of at least two polymer foam blocks for use in insulating panels for sealing insulating tanks according to claim 32, wherein: The chemical components include at least one reaction catalyst.

37. A method for preparing an assembly of at least two polymer foam blocks for use in insulating panels for sealing insulating tanks according to claim 32, wherein: The chemical composition includes at least one emulsifier.

38. The method for preparing an assembly of at least two polymer foam blocks for use in an insulation panel for a sealed insulation tank according to claim 32, wherein: The walls of the double belt laminator form a tunnel of rectangular or square cross-section.

39. The method for preparing an assembly of at least two polymer foam blocks for use in an insulation panel for a sealed insulation tank according to claim 32, wherein: When the two adjacent blocks are in operation, or when two opposite upper and lower surfaces of the two adjacent blocks have a temperature difference of at least 80° C., the minimum width L of the closed portion is reduced by at least 15%.

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