CN115053095A - Assembly of at least two foam blocks of a tank insulation panel - Google Patents

Abstract

An assembly of at least two foam blocks of a heat shield of the tank. The invention relates to an assembly of at least two foam blocks (20, 21), a first and a second foam block having surfaces called "abutment" surfaces, the two blocks (20, 21) being adjacently arranged such that the abutment surface of the first foam block and the abutment surface of the second foam block together form a channel having a minimum width L in the rest state, the abutment 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 abutment surface, said width L of the closing portion being reduced by at least 15% when the two opposing upper and lower surfaces of the two foam blocks have a temperature difference of at least 40 ℃.

Description

Assembly of at least two foam blocks of a tank insulation panel

Technical Field

The subject of the invention is an assembly of at least two polymer foam blocks of a heat insulating panel for sealing an insulated liquid tank, said at least two polymer foam blocks having technical features, in particular very specific mechanical and thermal properties, taking into account the specific application in which they are used. The invention also relates to a tank integrating such an assembly and to a vessel comprising one or more such tanks integrated in a membrane structure (also called monoblock tanks) or comprising a self-supporting/semi-supporting A, B or C tank for containing an extremely cold fluid, such as in particular liquefied natural Gas (GNL) or liquefied petroleum Gas (GPL), called cryogenic fluid, and to a vessel equipped with at least one such tank, a method for loading/unloading such a vessel and a transfer system for transferring a liquid product contained in such a vessel.

Finally, the present invention relates to a system and method for preparing a polymer foam block for such an assembly of at least two foam blocks.

The invention more particularly relates to foam blocks comprising an assembly of fiber reinforced Polyurethane (PUR) foam blocks and/or Polyisocyanurate (PIR) foam blocks, which are mounted in insulating panels. The invention will be described below in terms of such PUR and/or PIR foams, but the invention is not limited to such blocks and can be applied to a large number of polymer blocks, whether or not they are fibre reinforced (fibre loaded).

The polymer or polymers used are chosen according to their mechanical and thermal characteristics, which must have very specific mechanical and thermal characteristics, considering the specific application of the polymer, while being able to be produced as economically as possible.

Background

Polyurethane (PUR) foam is a porous insulating material consisting of pores that store gas with low thermal conductivity. PUR foams are used in many applications, such as in the automotive industry as flexible PUR foams or in thermal insulation as rigid PUR foams. The formation of polyurethane-type foams is well known to those skilled in the art. Formation of polyurethane-type foams 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 expanding agent (also referred to as a "blowing agent"). The condensation reaction is catalyzed in particular by compounds having basic and/or nucleophilic character, for example tertiary amines or metal-carboxylate complex compounds (such as tin or bismuth salts). Polyols commonly used in the manufacture of PUR foams are polyether polyols or polyester polyols. Thus, the formation of PUR foams requires large amounts of compounds.

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 of forming these foams is similar to the process of forming PUR foams. In particular, whether PUR foams, PIR foams or PUR-PIR foams are obtainable depends on the isocyanate/polyol ratio.

PUR foams, PIR foams and PUR-PIR foams are known to the person skilled in the art. However, the addition of fibers involves certain technical problems, such as the need for a good impregnation of the fibers, so that foams having a relatively high fiber content at least locally do not exist today.

These PUR, PIR and PUR-PIR foams are used in the form of blocks having a parallelepiped shape, which are placed in an encapsulating structure to form an insulating panel; such an encapsulation structure has a sealing membrane, usually made of stainless steel or invar, and such a thermal insulation panel may usually comprise one or two encapsulation structures, depending on the cold liquid (temperature of the cold liquid) contained in the tank.

In the technical field concerning the use of such foams for insulating panels for tanks, the panels are subjected to very cold temperatures on the surfaces exposed to the space inside the tank, for example about-160 ℃ in the case of GNL, while the space outside the tank (usually the hull) usually has a higher ambient temperature, which is at least equal to, and in practice much higher than, the temperature of the ambient air or sea, which is considered to be about 20 ℃.

Currently, two contiguous polymer foam blocks are:

-housed in wooden shells of the plywood or pressboard type, and connected together by means of couplings: for example

The condition of the tank; or

-in the form of a sandwich with an upper and a lower coating and the shells of these sandwich are joined together by a complex mat or fabric, which usually comprises three layers: such as MARK

This is the case for the tank.

Thus, there is currently no direct mechanical or chemical connection between adjoining polymer foam blocks.

Furthermore, in both of the above types of structures, two adjoining blocks of polymer foam form a linearly (usually vertically) extending space between them, which space must be blocked with glass wool or the like when the blocks are installed in the tank, in particular in order to prevent any thermosyphons from occurring.

The present invention aims to respond to these drawbacks by first solving the problems related to the possible occurrence of thermal phenomena in the space present between two adjacent foam blocks.

Disclosure of Invention

Under such circumstances, the applicant, after various studies and analyses, succeeded in developing an assembly of polymer foam blocks in which the foam blocks each have shapes or cross sections complementary to each other on facing abutment surfaces thereof, so that when each of the foam blocks shrinks due to cooling of a tank containing a cryogenic liquid or the like, a significant reduction in the width of the channel separating the two blocks is observed over at least a portion (referred to as a closed portion).

Thus, when the block is in use, the temperature gradient within the foam block is typically at least equal to 80 ℃, even at least equal to 100 ℃, wherein the thermal environment of the block between its upper and lower surfaces is very different-the upper surface being arranged on the content side of the tank and the lower surface being arranged on the outside side of the tank. Furthermore, in addition to the effect of this closure of the channel/duct separating two adjacent blocks to prevent any negative-face thermal phenomena, when the surfaces of each block come into contact, this closure portion will constitute a joining member, so that the two foam blocks will remain close to each other without any bending or buckling.

Thus, according to one possibility provided by the present invention, a direct mechanical connection can now be established between two adjoining foam blocks without the need for any attachment elements.

The present invention therefore aims to remedy the drawbacks of the prior art by proposing a particularly effective solution for industrially obtaining a fiber-reinforced PUR/PIR foam which can have (very) large dimensions, the mechanical/thermal properties of which are optimal and substantially similar between its initial state (at rest, the foam block is in a substantially homogeneous thermal environment) and its use/service state (in the use/service state, the foam block is in a non-homogeneous thermal environment), the temperature difference between the upper surface (content side of the tank) and the lower surface (external side of the tank) of which is at least equal to 40 deg.c, taking into account the thickness of the block, even at least equal to 80 ℃ to 100 ℃.

Advantageously, with respect to the embodiment in which there is a mechanical connection between two adjacent blocks, the production costs of the insulating panel can be significantly reduced by eliminating some of the intermediate connection elements and due to the saving of installation/assembly time.

The invention therefore relates to an assembly of at least two blocks of polymer foam, preferably polyurethane/polyisocyanurate foam, of a heat insulation panel for sealing an insulated liquid compartment, the density of the foam blocks having at least opposite upper and lower surfaces and side surfaces being 30kg/m ³ To 300kg/m ³ In between, the first and second foam blocks have surfaces referred to as "abutment" surfaces, the two blocks are arranged adjacently such that the abutment side surface of the first foam block and the abutment side surface of the second foam block form a channel or duct therebetween without any mechanical attachment, when the blocks are in a rest state, i.e., without a significant temperature difference between the two opposing upper and lower surfaces of the two blocks, the channel or duct has a minimum width L over at least one portion of said channel or said duct called the closing portion, the abutment surfaces of the first and second blocks have at least a non-flat or non-linear shape or cross-section, the non-planar or non-linear shape or cross-section is substantially complementary to the shape or cross-section of the other abutting surface of the first or second foam block, respectively.

According to the invention, the width L of the closed portion is reduced by at least 15% when the two abutting blocks are in operation, i.e. when the tank is at least partially filled with cold liquid and thus the two opposite upper and lower surfaces of the two abutting blocks have a temperature difference of at least 40 ℃, preferably at least 80 ℃.

According to a particularly advantageous aspect of the invention, the channels or ducts between the first and second foam blocks are "free of any mechanical attachment", in other words there is no mechanical attachment between the two blocks, or there is no mechanical attachment through the ducts or channels. The expression "mechanically attached" refers to attachment by means of a physical element that serves the function of attachment, such as a screw, bolt, etc., or even a link. For 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).

Advantageously, the object of the invention is to make the protrusions of a first polymer foam block interact with the protrusions of a second polymer foam block by snapping, snapping or even being of complementary shape, in order to provide a direct attachment (including a direct attachment by means of a compressible material as described below) between two adjoining foam blocks, in particular in the operational state of the tank.

The expression "cold liquid" means a cryogenic fluid substantially present in liquid form, such as in particular liquefied natural Gas (GNL) or liquefied petroleum Gas (GPL).

The expression "partly filled" means that the tank has been filled to at least 20% of its maximum storage capacity, in respect of the tank and its operating conditions. In particular, the assembly according to the invention is used for tanks capable of containing cold liquids.

The expression "minimum width L" means that the gap L represents the minimum gap at the closed portion. Of course, the gap in the channel or duct at the closing portion 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 closing portion, but in general this minimum gap L comprises the minimum gap present in the channel/duct at the closing portion.

The expression "a shape or cross-section substantially complementary to the shape (three-dimensional) or cross-section (two-dimensional) of the other abutting surface" means that one of the two shapes or cross-sections may be inside the other to fit together to form an abutting portion that is solid or quasi-solid for both surfaces of each block, i.e. in the case of quasi-solid, the abutting portion formed by the fitting together of the two substantially complementary shapes/cross-sections is at least 70% solid, or even preferably at least 90% solid.

The invention is described below in the context of two block polymer foams comprising polyurethane/polyisocyanurate foams. In particular, the invention is intended to be applied in particular to this type of polymer, but the invention is not limited to these polymers and it is possible to envisage other polymers having mechanical and thermal characteristics making them suitable for use in tanks or the like for preserving cryogenic liquids. Furthermore, according to a preferred embodiment, in particular for obvious production reasons, the two foam blocks are formed or composed of the same polymer foam, but it is conceivable that these blocks are made of different or at least locally different polymers.

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

The blocks of polyurethane/polyisocyanurate foam, preferably fiber-reinforced polyurethane/polyisocyanurate foam, comprise gas holes for storing gas, which advantageously have a low thermal conductivity, polyurethane/polyisocyanurate foam and fibers which occupy at least 95% of the weight of the block.

The foam blocks of the present invention comprise (only) Polyurethane (PUR) and/or Polyisocyanurate (PIR) foam, fibers (preferably fibers of a single nature, such as glass fibers), gas entrapped in said pores, and possibly a minimum of e.g. fillers or other functional auxiliaries, which occupy at most 5% of the weight of the foam block according to the present invention, even preferably at most 2% or 1% of the weight (thus a fiber reinforced polyurethane/polyisocyanurate foam block comprises pores for storing gas, polyurethane/polyisocyanurate foam and fibers occupying at least 98% or 99% of the weight of said block). In particular, the foam block according to the invention is obtained by:

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);

obtained in the above preparation operations, assisted by cutting operations, usually carried out on the upper surface of the block, to obtain a block of substantially parallelepiped or cubic shape.

The invention is intended to be applied particularly, but not exclusively, to the case where the foam blocks are mounted in a secondary layer, commonly referred to as "secondary" in insulation panels comprising a primary insulation layer and a secondary insulation layer, as shown, for example, in figures 1 and 2. For such applications, the foam blocks preferably have a thickness or height of at least twenty-five (25) centimeters (cm), and even more preferably at least 30cm or 35 cm.

Advantageously, the thermal performance of the fiber reinforced foam block is at least comparable to that of a non-fiber reinforced foam block of the prior art, more precisely, the thermal conductivity (measured at 20 ℃) of the foam block of thickness E is less than 30mW/m.k (milliwatts per meter kelvin) or 0.03W/m.k, preferably less than 25mW/m.k, even more preferably less than 23mW/m.k, and the thermal conductivity is less than 20mW/m.k when the upper surface of the block is at-160 ℃, when the foam block is in use, the liquid compartment containing the foam block contains GNL.

The fibre-reinforced foam blocks can thus be used both in tanks which are integrated in the supporting structure and in A, B or type C self-supporting/semi-supporting tanks defined according to the IGC rules (IMO), i.e. as external insulation in connection with self-supporting tanks for storing and/or transporting very cold liquids, such as GNL or GPL.

Other advantageous features of the invention are briefly described below:

preferably, the minimum width L is reduced by at least 50%.

Advantageously, said channel or duct has a non-linear path in the section plane P.

Since the present invention makes possible such a non-linear path of the channel or pipe, it is possible to reduce or even eliminate the occurrence of any thermosiphon.

Thus, as shown in fig. 6 and 7, the path of the conduit or channel, including a cross-section along a plane of the thickness of the polymer foam block, is not linear, that is, the path does not extend in a straight line connecting the upper and lower surfaces, except that the path includes multiple sections, a vertical section (through the thickness of the foam block), a horizontal section (through a plane perpendicular to a plane including a plane through the height or thickness of the foam block), or even an inclined section.

According to one embodiment, in the operating condition, said minimum width L is equal to 0, so that said two contiguous blocks are in contact at least at the closing portion.

Thus, when there is a direct mechanical connection between the adjoining blocks formed by the closing portion, which in this case constitutes a joining or connecting member between two adjoining blocks, it is possible to inhibit or prevent the separation of the abutting surfaces in the case when the heat-insulating panel of the sealed and heat-insulating tank is cold, in other words when the sealed and heat-insulating tank is used to contain an extremely cold fluid, which is referred to as a low temperature, such as in particular liquefied natural Gas (GNL) or liquefied petroleum Gas (GPL).

Preferably, the closing portion comprises a material having a compressibility at least equal to 15%, preferably at least equal to 50%, and preferably 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 such a thin thickness of material, which makes it possible to prevent any friction or any wear of the polymer blocks at their points of contact. However, such contact between two polymer masses (including contact in this case) is considered direct because the material is capable of significant compression, such that only a very small thickness-at most about one millimeter, or at most one or two millimeters-remains between the two masses-which allows the material to function only as a cushioning or mechanical stress-damping member between the two masses.

According to one possibility provided by the invention, at least one foam block, preferably both foam blocks, is made ofFiber reinforced foam composition, the average fiber density T of the fiber reinforced foam _f Between 1% and 60% of the weight of the fiber, preferably the fiber is 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.

The term "one or more fibers" or the expression "fiber reinforcement" means that the fibers may have two different forms:

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

In the form of at least one fibrous mat in which the fibres have no definite orientation, in other words the fibres are oriented substantially isotropically in the main plane of the layer of the mat. Likewise, the expression "fibrous mat" refers in itself to a clear technical definition known to the person skilled in the art.

Advantageously, said substantially complementary shape or section consists of a convex portion and a concave portion, respectively.

According to one possibility provided by the invention, the fibres consist of glass fibres, carbon fibres or any other organic or inorganic material, preferably glass fibres, typically of polymeric, metallic, ceramic, vitreous inorganic or organic nature, such as natural fibres, for example hemp or flax, preferably glass fibres.

The expression "fibres are long to continuous (les fibres a fibres)" (or "long to continuous fibres") means that all of these fibres (or, where appropriate, agglomerates of a group of fibres (fibres which are bonded or attached to one another)), i.e. at least 90% of the total weight of the fibres (considered in the case of isolation or agglomeration to form the equivalent of a single fibre), have a length of at least five (5) centimetres (cm).

Preferably, the average fiber density T _f Between 2% and 25%, preferably between 6% and 20%.

According to an advantageous embodiment, said complementary shape or section has a fiber density T greater than said average _f Preferably having a fiber density of at 1.2T _f To 3T _f A fiber density of between, preferably having a density of 1.4T _f To 2T _f Fiber density in between.

The expression "average fibre density T _f "refers to the density of fibers expressed as the weight of the fibers relative to the total weight of the fiber reinforced foam block, regardless of the variable percentage of these fibers localized (within the block).

Preferably, the channel or the conduit comprises an insulating material, preferably glass wool.

According to one aspect of the invention, the first and second foam blocks have a substantially parallelepiped or cubic shape.

It is understood here that the foam block having such a parallelepiped or cube shape may, in addition to the engagement members, have one or more local protrusions, for example in the form of anchors described below, or conversely in the form of hollow or hollow portions, while the foam block can still be considered to have the overall appearance shape of a parallelepiped or cube.

Advantageously, therefore, the lower surface and/or the upper surface of the blocks have anchors engageable with the engagement members of the insulating panels (not shown in the figures) in order to attach or anchor the foam blocks to the panels, preferably made of a material other than foam or fiber.

These anchors are advantageously metal elements (these anchors may also be made of plastic/polymer or composite material combining one or more polymers with ceramic and/or metal material), for example metal elements with L-shaped hook-like lugs or grooves/openings, for example L-shaped, for engaging with elements or parts of the insulation panels surrounding or housing the fibre-reinforced foam blocks. In the case of a membrane-type tank, this portion of the insulating panel may consist of a metallic sealing membrane, for example made of stainless steel or manganese steel, which seals the vessel, or, in the case of a self-supporting or semi-supporting A, B or C-type tank, of a vapour barrier (with the technical function of ensuring a seal with the surrounding environment outside the tank). In one possibility provided by the invention, the element or the part of the insulation panel (in the membrane-type tank) has a notch or the like for enabling engagement with a part of the anchor for mechanically maintaining or holding together the fibre-reinforced foam block with the other elements of the insulation panel. Of course, these anchors may also have the function of anchoring the foam blocks to the hull of the ship (in the case of membrane-type tanks) or to the self-supporting structure (in the case of A, B or C-type self-supporting tanks), it being understood that these anchors are the anchors that are then present on the lower surface of the foam blocks.

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

In the following, the terms "upper" and "lower" refer to the directions (sens) or directions given to the foam blocks after they have been in place in the insulation panels of the tank. Thus, when the heat insulating panel is placed in the tank, the upper surface or part of the foam block is located near or on the side of the contents of the tank, whereas in the case of tanks integrated or installed in ships for transporting and/or storing cryogenic liquids, the lower surface or part of the foam block is located towards or on the outside of the tank, that is to say the lower surface or part of the foam block is located in particular towards the hull of the ship.

It will thus be understood that these concepts or the terms "upper" or "lower" do not have any meaning during the manufacture or preparation of the foam block, since the foam block has not yet been installed in the insulation plate of the tank. In other words, it is entirely possible to prepare the foam blocks according to the invention in such a way that the foam blocks obtain a position opposite to their final mounting/assembly position in the insulation panel of the tank when they leave the preparation/production line.

Advantageously, according to a feature of the invention, in the rest condition, said width L is comprised between 1 mm and 12 mm, preferably between 1.5 mm and 6 mm.

Advantageously, the foam blocks, preferably fibre-reinforced foam blocks, have a density of 50kg/m ³ To 250kg/m ³ Preferably between 90kg/m ³ To 210kg/m ³ In the meantime. It should be noted here that for foam blocks used in self-supporting (type B, type C) or semi-supporting (type a) tanks, the density of the fibre reinforced foam block is preferably in the range of 30kg/m ³ To 90kg/m ³ In the case of a membrane-type tank, the preferred density of the fibre-reinforced foam blocks is in the range of 90kg/m ³ To 210kg/m ³ In the meantime.

According to one possibility provided by the invention, at least a portion of one of the abutment surfaces (preferably both abutment surfaces) comprises a composite layer or coating having a young's modulus greater than that of the complementary shape or cross-section.

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

The expression "gas cells for storing gas" means that the polyurethane/polyisocyanurate foam has closed gas cells 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 expanding agent.

According to one embodiment, the expression "(advantageously) gas of low thermal conductivity" means a gas originating from a blowing agent, which is obtained by chemical reaction thereof when this blowing agent is called "chemical blowing agent", said gas being generally carbon dioxide (CO) when the chemical blowing agent consists of water ₂ ) (ii) a Or gases derived from physical blowing agents, such as nitrogen (N) ₂ ) Oxygen (O) ₂ ) Carbon dioxide, hydrocarbons, fluorochlorocarbons, hydrochlorocarbons, hydrofluorocarbons, fluorochlorocarbons and mixtures thereof, and the corresponding alkyl ethers. Such as molecular nitrogen N ₂ Oxygen O ₂ Or CO ₂ Is in gaseous form. These gases are dispersed or dissolved in the liquid copolymer, for example, using a static mixer under high pressure. The nucleation and growth of bubbles creates a porous structure when the system is depressurized.

An elongated or stretched shape may be defined as a shape that extends in length, i.e. one dimension of the porous structure (i.e. its length) is larger than the other dimensions (width and thickness).

Advantageously, the fiber reinforced foam block according to the invention comprises between 0.1% and 5% by weight of a flame retardant of the organophosphorus type, 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 sulphate or cyanuric acid derivatives, or mixtures thereof.

The invention also relates to a sealed and thermally insulated tank integrated in a supporting structure, said tank consisting of:

-a tank integrated in a supporting structure comprising a sealed and insulated tank comprising at least one sealed metal membrane consisting of a plurality of metal strips or plates, which may comprise corrugations, and an insulating panel comprising at least one insulating barrier abutting the membrane, or

-A, B or type C tank as defined by IGC regulations, said A, B or type C tank comprising at least one insulating panel.

The tank according to the invention is characterized in that the heat shield comprises an assembly of at least two foam blocks as briefly described above.

The expression "IGC law" refers to the "International law for the Construction and Equipment of Ships for Bulk transport of Liquefied Gases (direct International de r theta gles relationships set up et l' knowledge of product resource utilization transport of gap details en vrac, or english International Code for the Construction and Equipment of ship cargo obtained gaps in Bulk", as known to the person skilled in the art, as the type B and type C tanks mentioned above.

It is noted that the expression "film-type tank" may be used in particular in the IGC regulations instead of the expression "bulk tank" to denote the same category of tanks, in particular installed on tankers for transporting and/or storing at least partially liquefied gas. The "membrane-type tank" is integrated in the support structure, whereas the A, B or C-type tank is considered to be a self-supporting or semi-supporting (in particular type a) tank.

Finally, the invention also relates to a vessel for transporting a cold liquid product, said vessel comprising at least one hull and a sealed and insulated tank as briefly described above, said tank being placed in said hull or mounted on said vessel when it is a type A, B or C tank as defined according to IGC regulations.

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

Advantageously, in the case of tanks consisting of tanks integrated in a supporting structure (membrane-type tanks), such a vessel comprises at least one sealed and insulated tank as described above, said tank comprising two successive sealing barriers, one being a primary sealing barrier in contact with the product contained in the tank and the other being a secondary sealing barrier arranged between the primary sealing barrier and the supporting structure, which secondary sealing barrier preferably comprises at least part of the wall of the vessel, the two sealing barriers alternating with two insulating barriers or a single insulating barrier arranged between the primary sealing barrier and the supporting structure.

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

According to the International Maritime Organization (IMO) regulations, such tanks are generally referred to as monoblock tanks, for example NO-type tanks, which include the following types: NO (nitric oxide)

、NO

、NO

Or NO 96

Or MARK

、MARK

Flex + or Flex.

Preferably, the membrane type tank or A, B or the C type tank contains liquefied natural Gas (GNL) or liquefied Gas (GL).

The invention also relates to a transfer system for transferring a cold liquid product, the system comprising a vessel as described above, an insulated transfer pipe arranged to connect the tank mounted in the hull of the vessel to a floating or onshore storage unit, and a pump for pumping a flow of cold liquid product from or to the vessel from or to the floating or onshore storage unit through the insulated transfer pipe.

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

The invention also relates to a process for preparing an assembly of at least two polymer foam blocks of the above-mentioned heat-insulating panel for a sealed and heat-insulating liquid tank, said polymer foam preferably being a polyurethane/polyisocyanurate foam, characterized in that it comprises the following steps:

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

c) forming the foam and expanding the foam,

wherein the expansion of the foam is physically restricted by a wall of a closed dual-band laminator, preferably the wall of the dual-band laminator forms a tunnel of rectangular or square cross-section, whereby the foam expands to obtain one of the foam blocks of the assembly,

characterized in that at least one wall of the dual-belt laminator is contoured to form a complementary shape or cross-section on a surface of the foam block referred to as an "abutment" surface for positioning adjacent to an "abutment" surface of another block comprising a complementary shape or cross-section to the foam block, such that the minimum width L of the enclosed portion is reduced by at least 15% when the two abutment blocks are in operation or when the two opposing upper and lower surfaces of the two abutment blocks have a temperature difference of at least 40 ℃, preferably at least 80 ℃.

It is noted here that in the case of making an assembly of two polymer foam blocks, the present invention is intended to encompass the use of a Double Belt Laminator (DBL), but it is contemplated that the two polymer foam blocks are obtained by free expansion, although in this case it is desirable to cut the foam blocks on one or more free expansion surfaces after the foam blocks are made/obtained.

Unlike the examples according to the invention, which are produced using DBLs, fiber-reinforced polyurethane/polyisocyanurate foams are produced by "free expansion", wherein the expansion of the fiber-reinforced foam is not restricted on at least one side or on at least one expansion surface, so that the expansion of the fiber-reinforced foam is free on this side or on this surface, unlike the molds which define the volume of the finished product. Normally, free expansion is achieved by omitting the (top) cover, while the side walls serve to prevent the foam from spilling at the sides, and the foam naturally expands upwards, usually beyond the upper ends of these side walls.

Therefore, after the free expansion step of the fiber reinforced polyurethane/polyisocyanurate foam, the fiber reinforced foam must be cut, typically at the upper surface of the fiber reinforced foam.

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

The expression "the fiber reinforcement extends substantially in a direction perpendicular to the direction of gravitational flow of the chemical component mixture" means that during the impregnation step b) these fiber reinforcements are in the form of low-thickness layers lying in a plane perpendicular to the direction of flow of the component mixture. Thus, as shown in fig. 3, a plurality of fibre-reinforced bodies having a minimum width L and being arranged in a stack are transported in the longitudinal direction i while the chemical component mixture is deposited from the dispenser onto the fibre-reinforced bodies, so that a gravity flow of the chemical component mixture is obtained/achieved. In other words, the mixture of chemical components, which may exit the dispenser under pressure, falls, at least under its own weight, onto the stacked fibre layers, thereby impregnating these fibre reinforcements from the upper layer to the lower layer.

The term "cream time (tempde creme)" used hereinafter refers to the time required from the mixing of the chemical components, so that the polymerization of the chemical components begins and thus the expansion and crosslinking of the component mixture in step c) begins (formation of a fiber-reinforced PUR/PIR foam). Such cream times are well known to those skilled in the art. In other words, cream time is the time until the mixture turns white after the chemical components are mixed at room temperature, under the action of bubble (gas-storing pores) nucleation and foam expansion. The cream time can be determined visually or using an ultrasonic sensor that detects thickness changes reflecting foam formation.

Advantageously, the fiber reinforcement has a variable fiber density and has an enhanced concentration or density in the region of the joining member such that the fiber density in this region is at the average fiber density T of the finished foam block _f Between 1.2 and 3 times, preferably at 1.4T _f To 2T _f In the meantime.

In addition or as an alternative not shown in the figures, at least a part of the abutting surfaces of the foam blocks (preferably at least a part of the surfaces having complementary shape or cross section) have a thin skin, in other words the outer surface thereof is mechanically attached or integrated with a coating or layer of another material having resistance to mechanical stresses, for example having an increased resistance to shear forces, in particular, or having adhesion and anti-friction properties when two identical surfaces are in contact with each other. It is also envisaged that the coating or layer extends from one abutment surface of the block to the other. In this case, the coating or layer is continuous and covers at least partially the lower surface of the block 20 or 21. The coating or layer may be composed of a composite material, for example, glass fiber reinforced plastic having a thickness of between 2 and 6 millimeters (mm).

Thus, when two adjoining insulation panels are moved away or separated from each other due to the cooling of the tank and thus each polymer foam block shrinks, the complementary shape or cross-section of each adjoining block will come into contact with its opposing shape or cross-section to collectively form a joining member that resists such separation, with an initial width L (at rest) that is low or small relative to the shrinkage of the polymer block upon cooling of the tank; from the structural point of view of the polymer foam block, the more reliably safe the resistance to such separation, the better the mechanical strength properties (in particular shear strength and tensile strength) of such a shape or cross-section.

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

Chemical blowing agents and physical blowing agents are well known to those skilled in the art and one or the other may be selected in appropriate amounts by those skilled in the art depending on the PUR/PIR foam desired to be obtained.

By polyol is meant any carbon structure containing at least two OH groups.

Since whether a PUR, PIR or PUR-PIR foam is obtained depends on the isocyanate/polyol ratio, a 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:

between 1:1 and 1:1.3, PUR polyurethane foams are obtained,

-between 1:1.3 and 1:1.8, a PUR-PIR polyurethane foam is to be obtained,

between 1:1.8 and 1:2.8 PIR polyurethane foams will be obtained.

Suitable polyisocyanates for forming PUR, PIR and PUR-PIR foams are known to those skilled in the art and include, for example, aromatic polyisocyanates, aliphatic cyclic polyisocyanates, aliphatic aromatic polyisocyanates, and mixtures thereof, advantageously aromatic polyisocyanates.

Examples of suitable polyisocyanates within the scope of the present invention include: aromatic isocyanates such as 4,4' -isomer, 2,4' -isomer and 2,2' -isomer of diphenylmethane diisocyanate (MDI), any of the compounds obtained by polymerization of these isomers, toluene-2, 4-and-2, 6-diisocyanate (TDI), m-phenylene diisocyanate (m-phenylene diisocyanate) and p-phenylene diisocyanate (p-phenylene diisocyanate), naphthalene-1, 5-diisocyanate (naphthalene-1, 5-diisocyanate); aliphatic isocyanates, alicyclic isocyanates, aliphatic aromatic isocyanates such as 1, 6-Hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI), 4' -dicyclohexylmethane diisocyanate (H12MDI), 1, 4-cyclohexane diisocyanate (CHDI), bis (isocyanomethyl) cyclohexane (H6XDI, DDI) and tetramethylm-xylylene diisocyanate (TMXDI). Any mixtures of these diisocyanates may also be used. Advantageously, the polyisocyanate is the 4,4' -isomer, the 2,4' -isomer and the 2,2' -isomer of diphenylmethane diisocyanate (MDI).

Generally, in the formation of PUR, PIR or PUR-PIR foams, it is known practice to add to the mixture comprising polyol, polyisocyanate and blowing agent a reaction catalyst, which may for example be selected from tertiary amines (such as N, N-dimethylcyclohexylamine or N, N-dimethylbenzylamine) or organometallic compounds based on bismuth, potassium or tin.

According to a preferred embodiment of the invention, advantageously the position of the tunnel wall of the Dual Band Laminator (DBL) is defined such 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 exit of the dual band laminator that is between 85% and 99%, preferably between 90% and 99%, of the expanded volume of the same fiber reinforced polyurethane/polyisocyanurate foam when expansion is free to occur (without restriction by such dual band laminator walls). In this case, a foam is obtained having cells of ovoid shape, preferably oriented along an axis E, so that the foam has the advantageous property of resistance to breakage along this direction E (measured according to ISO844 standard) and of combining this with the properties already described in the plane perpendicular to this axis E. The applicant has conducted tests and experiments to determine the above broad preferred ranges, but for the sake of clarity and conciseness, no description is made here.

By the above-described specific parameter settings for the expansion constraints of the fiber reinforced PUR/PIR foam in the DBL, a fiber reinforced PUR/PIR foam block is obtained, wherein at least 60%, typically more than 80%, even more than 90% of the pores used for storing the gas having a low thermal conductivity extend longitudinally along an axis parallel to the axis of the thickness E of the foam block, while the specific parameter settings contribute to an optimal homogeneity of the fiber reinforced foam block, in addition to specific choices regarding the properties of the fiber reinforcement and the viscosity of the chemical component mixture. These two characteristics (orientation of the pores and the fibre content T in the mass outside the zone or zones constituting the joining member) _f Uniformity of) makes it possible to obtain a fiber-reinforced foam block with excellent mechanical properties in the thickness E (compressive strength) and in the plane perpendicular to the thickness direction (tensile strength and relatively low coefficient of thermal shrinkage).

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

According to one possibility provided by the invention (not shown in the drawings), after the step of impregnating the fibrous reinforcement, a pressure application system (which may be, for example, a roller system called "nip roller") is applied to the mixture of components and at least the blowing agent used to impregnate the fibres, wherein the pressure application system is used to apply pressure to the upper surface of the component comprising the mixture and fibres. Such a pressure system on the one hand flattens the upper surface of the component and, by means of the pressure exerted on the component, helps to promote impregnation of the fibres in the mixture. The pressure system, which may consist of a single roller or a twin roller, is adjusted in its relative position above the liquid assembly and, where applicable, below the foam support to force the liquid assembly to spread completely uniformly. In this way, an equal amount of liquid components can be obtained at any point of 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 dispensing device, since the pressure system helps to make the liquid assembly uniform in thickness/width before most of its expansion.

Preferably, the dynamic viscosity η of the mixture of components is between 30 and 3000mpa.s (or between 0.03 and 3 pa.s), preferably between 50 and 1500mpa.s (or between 0.05 and 1.5 pa.s) at ambient temperature (25 ℃) and atmospheric pressure (1015 mPa).

The dynamic viscosity of the mixture of components can be determined using a viscometer (for example of the Brookfield type) or a rheometer (for example according to ISO2555 standard).

In general, it should be understood that the subject matter of the present invention uses materials/products that are commercially available or available, such that the properties of these materials/products, in particular the properties related to their density or viscosity (dynamic) are available in the specifications related to the material/product in question.

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

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, such that impregnation of each fiber reinforcement begins or occurs simultaneously or at the same rate through the thickness (or height) of the foam block and across the same width cross-section.

Advantageously, the blowing agent consists of a physical and/or chemical expanding agent, preferably a combination of these two types.

Preferably, the physical expanding agent is selected from: alkanes and cycloalkanes having at least 4 carbon atoms, dialkyl ethers, esters, ketones, acetals, fluoroalkanes, fluoroalkenes having 1 to 8 carbon atoms in the alkyl chain and tetraalkylsilanes having 1 to 3 carbon atoms, in particular tetramethylsilane, or mixtures thereof.

In this case, the compound may be propane, n-butane, isobutane, cyclobutane, n-pentane, isopentane, cyclopentane, cyclohexane, dimethyl ether, methyl ethyl ether, methyl butyl ether, methyl formate, acetone, and fluoroalkane, as exemplified by the compound; the selected fluoroalkanes are alkanes that do not destroy the ozone layer, such as trifluoropropane, 1,1,1, 2-tetrafluoroethane, difluoroethane and heptafluoropropane. Examples of fluoroolefins include 1-chloro-3, 3, 3-trifluoropropene, 1,1,1,4,4, 4-hexafluorobutene (e.g., HFO FEA1100 sold by DuPont).

According to a preferred embodiment of the invention, the physical expanding agent chosen is 1,1,1,3, 3-pentafluoropropane or HFC-245fa (sold by Honeywell corporation), 1,1,1,3, 3-pentafluorobutane or MFC 365 (such as Solkane sold by Solvay)

365MFC), 2,3,3, 3-tetrafluoropropan-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 (such as HFO FEA1100 sold by DuPont), trans-1-chloro-3, 3, 3-trifluoropropene (Solstance LBA by Honeywell) or mixtures thereof.

Advantageously, the chemical expansion agent consists of water.

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

Preferably, during step a) of mixing the chemical components, the temperature of each of the reagents used to obtain the polyurethane/polyisocyanurate is between 10 ℃ and 40 ℃, preferably between 15 ℃ and 30 ℃.

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

According to one possibility provided by the invention, an organic phosphorus flame retardant, 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, or an inorganic flame retardant, advantageously red phosphorus, expandable graphite, alumina hydrate, antimony trioxide, arsenic oxide, ammonium polyphosphate, calcium sulfate or cyanuric acid derivatives, or a mixture thereof, is also added to the mixture in step a).

It is also conceivable to use diethoxyethyl phthalate (DEEP), triethyl phosphate (TEP), dimethylpyrazole phosphate (DMPP) or cresyldiphenyl phosphate (CDP) as flame retardant.

When present in the composition, the flame retardant is present in an amount of between 0.01% and 25% by weight of the PUR/PIR foam.

Drawings

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

fig. 1 shows an insulation panel forming a first insulation layer or a barrier mounted on an insulation panel forming a second insulation layer of an insulation panel for sealing an insulation tank according to the prior art.

FIG. 2 is a sectional view showing a part of another insulated panel for sealing an insulated tank according to the prior art.

FIG. 3 is a schematic diagram showing various steps in a process for preparing a fiber reinforced PUR/PIR foam block for an assembly according to the present invention.

Fig. 4 is a schematic view of an embodiment of a foam block having a complementary shape or cross-section for forming a joining member with another foam block.

FIG. 5 is a schematic view of an embodiment of an assembly of two polymer foam blocks according to the present invention.

FIG. 6 is a schematic cross-sectional view illustrating one embodiment of a joining member of an assembly of two polymer foam blocks in accordance with the present invention.

FIG. 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.

Fig. 8 is a sectional view of a tank for carrying a carrier of liquefied gas and a quay for loading/unloading the tank, in which tank two insulation plate assemblies of the type shown in fig. 4 to 7 are installed.

Detailed Description

Figures 1 and 2 are intended to illustrate the use of polymer foam blocks in insulation panels for sealing insulated liquid compartments according to the prior art. In both figures, the polymer foam blocks do not have substantially the same shape and are in fact intended to be integrated in different types of insulation panels for sealed and insulated tanks.

It should be noted, however, 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 insulating panel sealing the insulating liquid compartment, except for the fact that it is possible to adapt the other technical aspects of the insulating panel to the new characteristics of the assembly of polymer foam blocks, in particular by removing all or some of the bolts 1 used for attaching said foam blocks.

Figure 1 shows 16 polymer foam blocks 2 forming a primary insulation layer 3, while a single piece of foam block 4 forms a secondary insulation layer 5. A wooden board 6 made of plywood is adhesively attached by adhesive bonding to the polymer foam blocks 2 forming the primary insulating layer 3, and anchoring strips 7 for anchoring primary sealing membranes 8 are fixed to some of the wooden boards, wherein the primary sealing membranes 8 are only in fig. 2 in MARK III

The form of a corrugated sealing membrane of type is visible.

Beneath the insulating block 2 forming the primary layer 3 is a Secondary sealing membrane 9, also known as a Rigid Secondary Barrier ("RSB"), which in the case of the insulating panel shown in fig. 1 is adhesively secured by adhesive to the polymeric foam block 4 forming the Secondary insulating layer 5. Finally, a wood board 13 made of plywood is fixed under the secondary layer 5.

Fig. 2 shows a mastic strip (binder de mass) 14 and a bolt 1, which bolt 1 is typically used to attach and secure the secondary layer 5 or insulation panel to the surface of the vessel 15 and thereby attach and secure the sealed insulation liquid tank to the surface of the vessel 15. As shown in fig. 8, these surfaces of the container 15 may comprise, in particular, the walls of a vessel, or the walls of a fixed storage tank, for example of the Gravity Based Structure (GBS) type, or the walls of a land-Based mobile storage tank.

Likewise, the present invention does not intend to modify the conventional elements of the sealed and 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 modification of one or more of the elements for the function of closing the channel separating two blocks or for the function of holding or joining between adjoining polymer foam blocks.

With respect to fig. 3, the 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. Such compounds are described, for example, in chapter 3.4.1 of the prior art document entitled "Kunststoffhandbuch, volume 7, Polyurethane", 3 rd edition published 1993 by Carl Hanser. These compounds include amine-based catalysts and catalysts based on organic compounds.

Preferably, the production of the fiber-reinforced PUR/PIR foam blocks 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 cellular structure during foam formation. These compounds are well known to those skilled in the art and may be, by way of example, foam stabilizers including silicones (such as siloxane-oxyalkylene copolymers) and other organopolysiloxanes.

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

According to one possibility provided by the invention, in step a) of the preparation process, the mixture of chemical components may comprise or consist of a plasticizer (e.g. a polybasic plasticizer, preferably a dibasic plasticizer), an ester, a monoalcohol carboxylic acid, such as a polyester of adipic acid, sebacic acid and/or phthalic acid. Depending on the reagents used, one skilled in the art will appreciate that the amount of plasticizer contemplated is typically between 0.05% and 7.5% by weight of the polyurethane/polyisocyanurate foam.

It is also possible to envisage using organic and/or inorganic fillers, in particular reinforcing fillers, such as siliceous minerals, metal oxides (for example kaolin, titanium oxides or iron oxides) and/or metal salts, etc., in the mixture of chemical components. If present in the mixture, the amount of these fillers is generally between 0.5% and 15% by weight of the PUR/PIR foam.

It should be noted that the present invention does not intend to augment the technical teaching of PUR/PIR foam formation in terms of the nature of the basic chemical components and optional functional agents and their respective amounts. Based on the specific choice of the properties of the fiber reinforcement, in particular the fiber density in the different fiber reinforcements and very specifically the fiber density in the complementary shape or cross-section for each foam block, and the equally specific choice of the foam used for impregnation of the reinforcement, the person skilled in the art will know how to obtain the different types of fiber-reinforced PUR/PIR foams currently involved in the preparation.

As shown in fig. 3, a plurality of fibre reinforcement 10 are spread out and aligned parallel to each other on or above a conveyor belt 11, which conveyor belt 11 is used to transport the reinforcement 10 and the components forming the PUR/PIR foam. In particular, within the framework of a preferred mode of production of the fiber-reinforced foam block according to the invention, the impregnation of the fiber reinforcement 10 is carried out by gravity, that is to say the mixture 12 of chemical components for obtaining a PUR/PIR foam, one or more blowing agents and any other functional agents is poured directly onto the fibers 10 from a liquid dispenser located above the fiber reinforcement 10.

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

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 the person skilled in the art and is selected such that, when the foam has just started to expand, the conveyor belt 11 conveys the assembly formed by the mixture 12 of components, foaming agent and fibres 10, for example to a dual-belt laminator (not shown in the figures), in other words the expansion of the PUR/PIR foam is thereby ended in the dual-belt laminator.

In such an embodiment with a dual-band laminator (DBL), the pressure system using one or two rollers is optionally arranged before the dual-band laminator, i.e. between the mixture impregnation zone on the fibers and the dual-band laminator. In the case of DBL, expansion of the foam volume occurs in the laminator when the expanded volume of the foam reaches between 30% and 60% of the expanded volume for the same free expansion of the foam (i.e. without any restriction). In this way, when the PUR/PIR foam is near or relatively near its maximum expansion, i.e. when the expansion of the PUR/PIR foam brings the foam close to all the walls of the dual-band laminator (which form a tunnel of rectangular or square cross-section), the dual-band laminator will be able to limit the expansion of the PUR/PIR foam in the second expansion phase of the PUR/PIR foam. Depending on the different expressions of the particular choice involved in the preparation, the gel point of the mixture of components, i.e. the moment at which the polymerization of the mixture of components reaches at least 60%, in other words the moment at which the mixture expands by 70% to 80% of its maximum volume, must occur in the dual-band laminator, possibly in the latter half of its length (i.e. closer to the outlet of the laminator than to the inlet of the laminator).

The function of simultaneously dispensing the mixture 12 of chemical component and foaming agent over the entire width B of the fibre-reinforced body 10 (corresponding to the width of the conveyor belt 11) can be ensured by a controlled liquid dispenser, not shown in the drawings. Such a dispenser comprises a channel for taking out an assembly formed by a mixture of chemical components and at least a foaming agent from a reservoir forming an agent mixer in which, on the one hand, all the chemical components and the foaming agent are mixed, and, on the other hand, in which, in particular, nucleation or even heating of the above-mentioned mixture takes place. The liquid assembly formed by the mixture 12 of chemical components and foaming agent is then distributed under pressure in two channels extending transversely so as to end respectively at two identical distributor plates 18, said distributor plates 18 extending across the width B (the length of each distributor plate being substantially equal to L/2), said distributor plates 18 comprising a plurality of nozzles for the flow of said mixture 12 onto the fiber reinforcement 10. These flow nozzles may consist of orifices having a calibrated section of a predetermined length. The length of these flow nozzles is thus determined such that the liquid flows out through all nozzles at the same flow rate, so that the impregnation of the fiber reinforcement 10 takes place at the same time or simultaneously over a cross section of the width B of the fiber reinforcement 10 and the surface density of the deposited liquid corresponding to each nozzle is equalized. In this way, taking a section of the width B of the fibres 10, simultaneously impregnating the fibres 10, so that the impregnation of the layers of fibres 10 by the mixture 12 takes place in the same way at all points on this section, helps to obtain, at the output of the double-belt laminator, a fibre-reinforced foam block in which the local fibre density corresponds exactly to the fibre density of each of the stacks of fibre-reinforcement when the mixture 12 is poured by gravity.

Cream time t in PUR/PIR foams _c An important aspect of the previous realization of good impregnation of the fiber reinforcement 10 is the choice of the specific viscosity of the liquid (consisting of the mixture 12 of chemical components and foaming agent) which is linked to the specific properties of the respective fiber reinforcement, which vary depending on the fiber density. The viscosity range chosen, together with the permeability characteristics of the fiber reinforcement, must be such that good penetration of the liquid into the first layer of fibers 10, in order to reach the subsequent layers, up to the last layer (the lower layer of fibers 10, i.e. the layer located at the very bottom of the stack of fiber reinforcements), is achieved in such a way that the impregnation time ti of the fibers 10 is within a time range determined by the chemical composition, which time range corresponds approximately to, but is always less than, the cream time t _c . The viscosity of the mixture of components 12 is selected, for example, by heating, the addition of plasticizers and/or a more or less pronounced nucleation, so that the impregnation of all fibers 10 by the mixture of chemical components and blowing agent 12 in a cross section of the width B takes place before the cream time, i.e. before the PUR/PIR foam begins to expand or just before it begins to expand.

Fiber reinforced foam blocks are intended for use in very specific environments and must therefore guarantee their specific mechanical and thermal properties. The fibre-reinforced foam blocks obtained by the above preparation therefore usually form part of an insulating panel, i.e. in the example used in fig. 4 or 5, the fibre-reinforced foam blocks are located in the upper or main panel and/or the lower or secondary panel of such an insulating panel for a tank 71 for receiving an extremely cold liquid (such as GNL or GPL). For example, such tanks 71 may be mounted on Storage tanks, Floating barges, etc. on the ground (such as Floating Storage Regasification Units (FSRU), or Floating Liquefied Natural Gas (FLNG)), or even on a vessel for transporting the liquid fuel between two ports, such as a carrier of Liquefied Gas.

Fig. 4 shows one embodiment of a polymer foam block 20, which polymer foam block 20 is intended to form an assembly according to the invention together with another polymer foam block 21. It can be seen that this foam block 20 includes L-shaped lug portions or projections 24, 25 on both side surfaces 22, 23, said L-shaped lug portions or projections 24, 25 on each side surface 22, 23 of the block 20 being inverted or opposed so that these lug portions or projections 24 or 25 mate with lug portions or projections 24 or 25 on an adjacent foam block 21, as shown in fig. 6 or 7.

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 an expandable insulating material 28, such as glass wool, to prevent any detrimental thermal phenomena. These elements 28 and 31 may be secured by adhesive bonding, stapling or simply by using a third element to be positioned for subsequent holding in place by pressure.

It is also important to note that the conduit or channel 30 does not extend the entire height or thickness of the foam blocks 20, 21, and in the embodiment shown in fig. 5 and 6, the vertical portions 26, 27 of the conduit or channel 30 extend at most 2/3 of the height or thickness of the foam blocks. The complementary shapes or cross sections 24, 25 of the adjoining foam blocks 20, 21 thus make it possible, on the one hand, to ensure the joining, retaining or maintaining function between the blocks when the tank 71 is in the operating state (i.e. a cold liquid load of at least 20% of the maximum storage volume of the tank), and on the other hand to avoid any undesired thermal phenomena, such as thermosiphons.

When the abutting polymer foam blocks contract, the closed portion or portions 60 of the conduit or channel 30 most likely to come into contact may advantageously comprise a flexible material 31 having high plasticity in order to absorb mechanical stresses associated with the tension forces caused by the proximity of the abutting foam blocks 20, 21. When the adjoining polymer foam blocks 20, 21 are collapsed, the portions of the duct or channel 30 that are most likely to move away from each other advantageously have an expandable insulating material 28 as described previously, or even the same flexible material 31 as described above, which is capable of elastic and/or plastic deformation while maintaining a mechanical connection between the two blocks 20 and 21, possibly forming a closed wall.

In the embodiment shown in fig. 6, one or more of the enclosed portions 60 of the channel or conduit 30 includes an inclined plane having a length of at least 1/3 the height or thickness of the block 20 or 21. Since the length of this closing portion 60 is large, if the surfaces come into contact when the blocks 20, 21 contract, this closing portion 60 can be used as an engagement member, making it possible to mechanically connect two adjoining blocks 20, 21 and absorb forces that make the blocks 20, 21 prone to buckling or bending.

Fig. 7 shows an alternative embodiment of a joint member according to the invention. In this example, unlike the embodiment of fig. 4 to 7, the closing portion 60 or, if applicable, the engaging member, does not have a point of symmetry with respect to the two blocks 20, 21. Specifically, in this embodiment, closure portion 60 is from knuckle 33, which knuckle 33 extends in a first proximal portion 34, starting from side surface 23 of block 21, to end portion 35, wherein first proximal portion 34 is thinner-its thickness or height is reduced-and widened in a second section, end portion 35 is wider-its thickness or height is at least twice that of proximal portion 34-and end portion 35 is longer, its length exceeding twice that of proximal portion 34. The closing portion 60 has, on the other contiguous block 20, a shape or cross section complementary to the hooking tongue 33, the hooking tongue 33 being composed of a compact hooking foot 36. This asymmetry between the two complementary shapes or sections 33, 36 has the following advantages compared to the embodiment of fig. 5 to 7: so that a compact shape or cross-section 36 can be created, which compact shape or cross-section 36 is better able to counteract the distancing of the other foam mass 21 when the two surfaces of the two masses 20, 21 are in contact at the closing portion 60, for example when the position of the mass 20 or 21 in the tank makes it easier to contract.

Referring to fig. 8, a view, partially cut away, of a liquefied gas carrier 70 shows a generally prismatic sealed insulated tank 71 mounted in the carrier's catamaran hull 72. The walls of the tank 71 comprise a primary sealing barrier for contact with the GNL contained in the tank, a secondary sealing barrier arranged between the primary sealing barrier and the double hull 72 of the carrier, and two heat insulating barriers arranged between the primary sealing barrier and the secondary sealing barrier and between the secondary sealing barrier and the double hull 72, respectively.

In a manner known per se, the loading/unloading transfer pipes 73 arranged on the upper deck of the carrier body can be connected by suitable connections to a marine or harbour for transferring GNL cargo from the tank 71 or to the tank 71.

Fig. 8 shows an example of a marine terminal comprising a loading dock 75, a subsea pipeline 76 and an onshore facility 77. Terminal 75 is a fixed offshore facility that includes a movable arm 74 and a tower 78 supporting movable arm 74. The movable arm 74 carries a series of insulated flexible conduits 79, said insulated flexible conduits 79 being connectable to the loading/unloading conveyor conduit 73. The directable movable arm 74 can be adjusted to accommodate all sizes of liquefied gas carriers. Connecting piping (not shown) extends inside the tower 78. The loading and unloading station 75 enables loading and unloading of the liquefied gas carrier 70 from the onshore facility 77 or loading and unloading of the liquefied gas carrier 70 to the onshore facility 77. The installation comprises a tank 80 for storing liquefied gas and a connecting pipe 81 connected to the terminal 75 via the underwater pipeline 76. The subsea conduit 76 enables remote (e.g., 5km) transfer of liquefied gas between the loading dock 75 and the onshore facility 77, which enables the liquefied gas carrier 70 to be maintained at a remote distance from the shore during the loading and unloading operation.

Pumps on carrier 70 and/or pumps mounted on onshore facilities 77 and/or pumps mounted on loading dock 75 are used to generate the pressure required to deliver the liquefied gas.

As mentioned above, the subject matter of the invention, i.e. in this case the fibre-reinforced polyurethane/polyisocyanurate foam blocks, is not intended for or only suitable for tanks integrated in supporting structures, but also for A, B and type C tanks defined in the IGC regulations as validated at the date of filing of the present patent application, unless a considerable substantial modification of this A, B and type C tanks is made, the subject matter of the invention is also applicable to future versions of this specification, and furthermore, it is to be understood that the fibre-reinforced PUR/PIR foam blocks according to the invention can become suitable for other types of tanks in the case of a modification of the IGC regulations.

Some experiments and tests performed by the applicant are given below to enable the subject matter of the present invention and its scope to be evaluated, while it should be noted that many tests/experiments have been performed and may be provided later if needed/necessary.

A number of tests were carried out on full-size PUR/PIR foam blocks of the type shown in figures 6 and 7, which were subjected to temperature conditions indicative of their operating conditions, the temperature difference between the upper and lower surfaces of the foam block being greater than 80 ℃ (as in the case of tanks containing lng).

On average, a reduction of the minimum width L of the channel/duct at the closing portion 60 of more than 15%, in practice more than 50%, is observed. In case the width L of the channel/duct at the closing portion 60 is initially small/low (about 1-3 millimeters (mm)), during use of the tank (when the foam blocks 20, 21 are in an operative state) the blocks are in contact by the closing portion 60, which enhances the mechanical stability of the block assembly and prevents bending/buckling.

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

[ Table 1]

Although the invention has been described in connection with a number of specific embodiments, it is obvious that the invention is not restricted thereto, and that it comprises all technical equivalents of the components described and their combinations if they fall within the scope of the invention.

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

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

Claims (19)

1. An assembly of at least two polymer foam blocks (20, 21) of a thermally insulating panel for sealing an insulated liquid tank (71), the polymer foam preferably being a polyurethane/polyisocyanurate foam, the foam blocks (20, 21) having at least opposing upper and lower surfaces and side surfaces having a density of 30kg/m ³ To 300kg/m ³ In between, a first and a second foam block (20, 21) having surfaces called "abutment" surfaces (22, 23), the two blocks (20, 21) being arranged adjacently such that the abutment side surface (22) of the first foam block (20) and the abutment side surface (23) of the second foam block (21) form between them a channel or duct (30) having a minimum width L on at least one portion of the channel or duct called the closed portion, when the blocks (22, 23) are in a rest state, i.e. when there is no significant temperature difference between the two opposite upper and lower surfaces of the two blocks, the channel or duct having a minimum width L on at least one portion of the channel or duct called the closed portion, the first foam block (20, 21) having a surface called the "abutment" surface (22, 23)Said abutment surfaces (22, 23) of the blocks and of the second block (20, 21) having at least a shape or a cross section (24 or 25) substantially complementary to the shape or the cross section (24 or 25) of the other abutment surface (22 or 23) of the first or of the second foam block (20 or 21), respectively,

the width L of the closed portion is reduced by at least 15% when the two abutting blocks are in operation, i.e. when the two opposing upper and lower surfaces of the two abutting blocks have a temperature difference of at least 40 ℃, preferably at least 80 ℃.

2. The assembly of claim 1, wherein the width L is reduced by at least 50%.

3. Assembly according to claim 1 or 2, wherein the channel or duct (30) has a non-linear path in a cross-sectional plane P.

4. Assembly according to any one of claims 1 to 3, wherein, in the operating condition, the minimum width L is equal to 0, so that the two abutment blocks are in contact at least at the closing portion.

5. Assembly according to any one of claims 1 to 3, wherein the closing portion comprises a material (28 or 31) having a compressibility at least equal to 15%, preferably at least equal to 50%, and preferably consists of glass or rock wool (28) or of an elastomer (31).

6. Assembly according to any one of the preceding claims, wherein the substantially complementary shapes or sections (24, 25) consist of a male portion and a female portion, respectively.

7. Assembly according to any one of the preceding claims, wherein at least one foam block (20 or 21), preferably both foam blocks (20, 21), consists of fibre-reinforced foam, said foam block being made of a fibre-reinforced foamAverage fiber density T of fiber-reinforced foams _f Between 1% and 60% by weight of the fibres (10), preferably the fibres (10) are long or continuous; the fibers (10) consist of glass fibers, basalt fibers, hemp fibers or any other organic or inorganic material, preferably the fibers (10) consist of glass fibers.

8. The assembly of claim 7, wherein the complementary shape or cross-section has a greater than the average fiber density T _f Preferably having a fiber (10) density of at least 1.2T _f To 3T _f Preferably having a fibre (10) density of between 1.4T _f To 2T _f The density of the fibers (10) in between.

9. The assembly of any preceding claim except claim 4, wherein the channel or the pipe comprises an insulating material, preferably glass wool.

10. The assembly according to any one of the preceding claims, wherein the first and second foam blocks (20, 21) have a substantially parallelepiped or cubic shape.

11. The assembly according to any one of the preceding claims, wherein the width L is between 1 and 12 mm, preferably between 1.5 and 6 mm, in a rest state.

12. Assembly according to any one of the preceding claims, wherein the foam blocks (20, 21), preferably fibre-reinforced foam blocks, have a density of 50kg/m ³ To 250kg/m ³ Preferably between 90kg/m ³ To 210kg/m ³ In the meantime.

13. Assembly according to any one of the preceding claims, wherein at least a part of one of the abutment surfaces (22 or 23), preferably both abutment surfaces (22 and 23), comprises a composite layer or coating having a young's modulus greater than that of the complementary shape or cross-section.

14. A sealed and insulated tank (71), said tank (71) consisting of:

-a tank integrated in a supporting structure comprising a sealed and insulated tank comprising at least one sealed metal membrane consisting of a plurality of metal strips or plates, which may comprise corrugations, and an insulating panel comprising at least one insulating barrier adjacent to the membrane, or

A, B or type C tank, defined according to the IGC regulations, said A, B or type C tank comprising at least one thermally insulating panel,

characterized in that it comprises an assembly of at least two foam blocks (20, 21) according to any of the preceding claims.

15. A vessel (70) for transporting a cold liquid product, said vessel comprising at least one hull (72) and a sealed and insulated tank (71) according to claim 13, said sealed and insulated tank being placed in said hull or mounted on said vessel (70) when said tank (71) is a type A, B or C tank defined according to IGC rules.

16. Transfer system for transferring a cold liquid product, the system comprising a vessel (70) according to the preceding claim, an insulated transfer pipe (73, 76, 79, 81) arranged to connect the tank (71) mounted in the hull of the vessel to a floating or onshore storage unit (77), and a pump for pumping 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 pipe.

17. A method for loading or unloading a vessel (70) according to claim 15, wherein cold liquid product is transferred from or from a floating or onshore storage unit (77) to the vessel (71) by the insulated transfer piping (73, 76, 79, 81).

18. A process for the preparation of an assembly of at least two polymer foam blocks (20, 21) of a heat insulating panel of a sealed and insulated liquid tank (71) according to any of claims 1 to 13, the polymer foam preferably being a polyurethane/polyisocyanurate foam, characterized in that the process comprises the steps of:

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

c) forming the foam and expanding the foam,

wherein the expansion of the foam is physically restricted by a wall of a closed two-belt laminator, preferably the wall of the two-belt laminator forms a tunnel of rectangular or square cross-section, whereby the foam expands to obtain one of the foam blocks of the assembly,

characterized in that at least one wall of the double belt laminator is contoured to form a complementary shape or cross-section (24, 25) on a surface of the foam block (20 or 21) referred to as an "abutment" surface (22, 23) for positioning adjacent to an "abutment" surface (22 or 23) of another block (20 or 21) comprising a shape or cross-section (24, 25) complementary to the foam block (20 or 21) such that the minimum width L of the closed portion is reduced by at least 15% when the two abutment blocks (22, 23) are in operation or when the two opposing upper and lower surfaces of the two abutment blocks have a temperature difference of at least 40 ℃, preferably at least 80 ℃.

19. A process for the preparation of a foam block according to claim 18, comprising a step b) between step a) and step c), said step b) comprising an impregnation step: impregnating a plurality of fibre (10) reinforcements by gravity flow of the mixture of chemical components, the fibre (10) reinforcements being arranged in a stack in which the fibre (10) reinforcements extend substantially in a direction perpendicular to the direction of gravity flow.

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