Heat-insulated box for a sealed and thermally insulating tank

Abstract

The invention relates to a heat-insulating box (7) for a sealed and thermally insulating tank intended to contain a liquefied gas, the heat-insulating box comprising a cover panel (21), a base panel (22) spaced from the cover panel (21), and side panels (23, 24). The side panels (23, 24) define an interior space (25) of the heat-insulating box and comprise longitudinal side panels (23) and transverse side panels (24). A plurality of internal partitions (33, 34) divides said interior space (25). The plurality of internal partitions (33, 34) comprises transverse internal partitions (34) and longitudinal internal partitions (33).A transverse side panel (24) has mortises (60, 160, 360) extending in a vertical plane and opening into said interior space (25), each said mortise (60, 160, 360) receiving one end (36, 336) of a said longitudinal internal partition (33) and said end (36, 336) being fixed to said transverse side panel (24) in said mortise (60, 160, 360). Figure for abstract: Fig. 5.

Description

Title of the invention: Heat-insulating box for a sealed and thermally insulating tank Technical field

[0001] The invention relates to the field of sealed and thermally insulating membrane tanks. In particular, the invention relates to the field of sealed and thermally insulating tanks for the storage and / or transport of low-temperature liquefied gas, such as tanks for the transport of Liquefied Petroleum Gas (also called LPG) having, for example, a temperature between -50°C and 0°C, or for the transport of Liquefied Natural Gas (LNG) at approximately -162°C at atmospheric pressure. These tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank can be intended for the transport of liquefied gas or for receiving liquefied gas used as fuel for the propulsion of the floating structure. Technological background

[0002] Known in the state of the art is a sealed and thermally insulating tank, integrated in a supporting structure, said tank comprising a tank wall fixed to a supporting wall of the supporting structure, the tank wall comprising in the direction of the thickness, from the outside to the inside of the tank, a thermally insulating barrier retained on the supporting wall, and a sealing membrane supported by the thermally insulating barrier.

[0003] It is known that in such a tank wall, the thermally insulating barrier may comprise a plurality of juxtaposed heat-insulating boxes, the heat-insulating boxes comprising a bottom panel, a cover panel, side panels and internal sails which delimit spaces in which perlite is placed.

[0004] In service, the walls of the tank are subjected to numerous stresses. In particular, the walls are subjected to compressive forces due to the loading of the tank, to thermal stresses during cooling and to forces due to the dynamic shocks of the fluid contained in the tank. Summary

[0005] It has been observed that in the aforementioned heat-insulated boxes, the side panels are vulnerable to buckling when the compressive forces applied to the heat-insulated box in the thickness direction of the tank wall, in particular the compressive forces due to the dynamic impacts of the fluid on the tank wall, are significant.

[0006] An idea at the basis of the invention is thus to propose a heat-insulated box whose side panels are less vulnerable to buckling.

[0007] According to one embodiment, the invention provides a heat-insulating box for a sealed and thermally insulating tank intended to contain a liquefied gas, the heat-insulating box comprising a cover panel, a bottom panel spaced from the cover panel in a vertical direction, and side panels, the side panels extending in the vertical direction and connecting the bottom panel and the cover panel along the edges of the bottom panel and the cover panel so as to delimit an interior space of the heat-insulating box, the side panels comprising longitudinal side panels and transverse side panels, the longitudinal side panels extending in a longitudinal direction and the transverse side panels extending in a transverse direction, the transverse direction being orthogonal to the longitudinal direction,and the longitudinal direction and the transverse direction being orthogonal to the vertical direction, , said heat-insulating box further comprising a plurality of internal partitions arranged in a vertical plane and dividing said interior space into a plurality of compartments, the compartments being filled with a heat-insulating lining, the plurality of internal partitions comprising transverse internal partitions extending in the transverse direction and spaced from each other in the longitudinal direction, and longitudinal internal partitions extending in the longitudinal direction and spaced from each other in the transverse direction, wherein a transverse side panel has mortises extending in a vertical plane and opening into said interior space, each said mortise receiving one end of a said longitudinal internal partition and said end being fixed to said transverse side panel in said mortise.

[0008] Fixing the ends of the longitudinal internal partitions in the mortises improves the resistance of the transverse side panel to buckling. Correlatively, this fixing holds the ends of the longitudinal internal partitions in the mortises, which also improves the resistance of the longitudinal internal partitions to buckling.

[0009] According to embodiments, such a heat-insulating box may comprise one or more of the following characteristics.

[0010] According to one embodiment, the transverse side panels have a greater thickness, in the longitudinal direction, which is strictly greater than a greater thickness, in the transverse direction, of the longitudinal side panels. This further improves the resistance of the transverse side panels to buckling.

[0011] The mortises may have various sections. According to one embodiment, the mortises have a dovetail section containing, orthogonally to the vertical direction, and the ends of the longitudinal internal partitions have a contained dovetail section, orthogonal to the vertical direction. These dovetail sections tend to retain the transverse side panel by preventing it from buckling towards the outside of the heat-insulating box, in other words in a direction away from the interior space of the heat-insulating box. Thus, the resistance of the transverse side panel to buckling is further improved. According to another embodiment, the mortises and the ends of the longitudinal internal partitions have a rectangular section, orthogonal to the vertical direction.

[0012] According to one embodiment, the longitudinal internal partitions each have a series of first notches, and the transverse internal partitions each have a series of second notches, the second notches being complementary to the first notches. This allows the internal partitions to be installed by fitting into the interior space of the heat-insulating box. According to one embodiment, the first notches are turned towards the bottom panel and the second notches are turned towards the cover panel.

[0013] According to one embodiment, said transverse side panel comprises spacer portions, each said spacer portion extending between two adjacent mortises or between a mortise and a longitudinal side panel.

[0014] Thus, a spacer portion defines one edge of two adjacent mortises. The transverse side panel provided with the mortises can therefore be manufactured from a limited number of pieces if the spacer portions are fixed pieces, or in one piece if the transverse side panel is formed in one piece.

[0015] The spacer portions can be made in various ways.

[0016] According to one embodiment, the transverse side panel comprises an outer plate and the spacer portions are fixed to the outer plate on a face of the outer plate facing the interior space of the heat-insulating box. For example, the spacer portions are fixed to the outer plate by staples, or screws or nails, passing through the outer plate, or by gluing, or by gluing and stapling.

[0017] Thus, the geometry and / or dimensions of the spacer portions can be easily adapted in order to facilitate the installation of the heat-insulating lining in the compartments, without modifying the external plate.

[0018] According to one embodiment, the spacer portions are internal plates. According to a particular embodiment, the internal plates are in contact against the cover panel and the bottom panel. This can facilitate the installation of the heat-insulating lining in the compartments, in particular if the heat-insulating lining is in the form of glass wool. Indeed, the internal plates then do not form a shoulder likely to hinder the insertion of the glass wool, and the thickness of the internal plates in the longitudinal direction can be adapted according to the glass wool elements available.

[0019] According to one embodiment, the spacer portions are internal cleats. According to a particular embodiment, the internal cleats are spaced from the bottom panel and the cover panel in the vertical direction. Thus, an internal cleat defines an edge of two adjacent mortises while being spaced from the bottom panel and the cover panel.

[0020] According to another embodiment, the spacer portions are formed in a single piece with the transverse side panel, in other words the transverse side panel comprising the spacer portions is formed in a single piece and the mortises are formed in the thickness of the transverse side panel in the longitudinal direction, for example by machining in the transverse side panel.

[0021] Thus, it is easier to obtain the desired positions of the mortises within given dimensional tolerances, because these positions do not depend on the fixing of several spacer portions.

[0022] According to one embodiment, said ends of the longitudinal internal partitions are fixed to said transverse side panel by staples, or screws or nails, passing through the transverse side panel and being fixed in end faces of the longitudinal internal partitions.

[0023] In this way, the fixing of the ends of the longitudinal internal partitions in the mortises is easy to achieve.

[0024] The side panels can be joined to each other in various ways. According to one embodiment, the longitudinal side panels and the transverse side panels are fixed to each other by means of screws or staples or nails, or by gluing. According to another embodiment, the longitudinal side panels and the transverse side panels are held to each other by form cooperation.

[0025] According to one embodiment, the longitudinal internal partitions and the transverse internal partitions are in contact against the cover panel and the bottom panel.

[0026] Thus, the resistance of the heat-insulating box to compression forces in the vertical direction is improved.

[0027] According to one embodiment, each longitudinal internal partition comprises a central panel and a projection formed at one end of the central panel, each said projection forming a said end of a longitudinal internal partition received in a said mortise and cooperating with a stop surface that said mortise comprises, the stop surface being included in a horizontal plane, the horizontal plane being orthogonal to the vertical direction and being located between the cover panel and the bottom panel.

[0028] According to one embodiment, each longitudinal internal partition comprises an upper longitudinal slat fitted onto the central panel and in contact against the cover panel, and a lower longitudinal slat fitted onto the central panel and in contact against the bottom panel.

[0029] The longitudinal internal partitions thus have, orthogonal to the vertical direction, an I-beam cross-section. This further improves the resistance of the longitudinal internal partitions to buckling.

[0030] According to one embodiment, a longitudinal side panel has additional mortises extending in a vertical plane and opening into said interior space, each said additional mortise receiving one end of a said transverse internal partition and said end being fixed to said longitudinal side panel in said additional mortise.

[0031] Fixing the ends of the transverse internal partitions in the additional mortises increases the resistance of the longitudinal side panel to buckling. Correlatively, this fixing holds the ends of the transverse internal partitions in the mortises, which also improves the resistance of the transverse internal partitions to buckling.

[0032] According to one embodiment, the additional mortises have a containing dovetail section, orthogonal to the vertical direction, and the ends of the transverse internal partitions have a contained dovetail section, orthogonal to the vertical direction. These dovetail sections tend to retain the longitudinal side panel by preventing it from buckling towards the outside of the heat-insulating box, in other words in a direction away from the interior space of the heat-insulating box. Thus, the resistance of the transverse side panel to buckling is further improved. According to another embodiment, the additional mortises and the ends of the transverse internal partitions have a rectangular section, orthogonal to the vertical direction.

[0033] According to one embodiment, each transverse internal partition comprises a central panel and an additional projection formed at one end of the central panel, each said additional projection forming a said end of a transverse internal partition received in a said additional mortise and cooperating with a stop surface that said additional mortise comprises, the stop surface being included in a horizontal plane, the horizontal plane being orthogonal to the vertical direction and being located between the cover panel and the bottom panel.

[0034] According to one embodiment, each transverse internal partition comprises a plurality of upper transverse slats fitted onto the central panel and in contact against the cover panel, and a plurality of lower transverse slats fitted onto the central panel and in contact between the bottom panel, the upper transverse slats extending between two adjacent upper longitudinal slats or between an upper longitudinal slat and a longitudinal side panel, and lower transverse slats extending between two adjacent lower longitudinal slats or between an adjacent lower longitudinal slat and a longitudinal side panel.

[0035] The transverse internal partitions thus have, orthogonal to the vertical direction, an I-shaped profile cross section (“Lbeam” in English). This further improves the resistance of the transverse internal partitions to buckling.

[0036] According to one embodiment, the bottom panel projects beyond said transverse side panel so as to have a rim located outside the interior space of the heat-insulating box, and at least one cleat is arranged on the rim.

[0037] According to one embodiment, the invention also provides a sealed and thermally insulating tank, integrated in a supporting structure, said tank comprising a tank wall fixed on a supporting wall of the supporting structure, the tank wall comprising in a thickness direction, from the outside towards the inside of the tank, a thermally insulating barrier retained on the supporting wall, and a sealing membrane supported by the thermally insulating barrier, the thermally insulating barrier comprising a plurality of juxtaposed heat-insulating boxes, in which at least one said heat-insulating box is according to any one of the aforementioned embodiments and the vertical direction of the heat-insulating box is parallel to the thickness direction.

[0038] Since the heat-insulating box has improved resistance of the transverse side panels and the longitudinal internal partitions to buckling, the tank wall is able to withstand greater compressive forces along the thickness direction. The cover panel of the heat-insulating box can form a support surface for the sealing membrane.

[0039] According to one embodiment, the thermally insulating barrier is retained on the load-bearing wall by anchoring members.

[0040] According to an embodiment in which the bottom panel of the heat-insulating box has the aforementioned rim and cleat, an anchoring member cooperates with the cleat of said heat-insulating box.

[0041] In one embodiment, the liquefied gas is LNG, namely a mixture with a high methane content stored at a temperature of approximately -162°C at atmospheric pressure. Other liquefied gases may also be considered, in particular ethane, propane, butane or ethylene. Liquefied gases may also be stored under pressure, for example at a relative pressure of between 2 and 20 bar, and in particular at a relative pressure of around 2 bar. The tank may be produced using different techniques, in particular in the form of an integrated membrane tank or of a self-supporting tank.

[0042] Such a tank may be part of a land-based storage facility, for example for storing LNG, or may be installed in a floating, coastal, or deep-water structure, including an LNG carrier, a floating storage and regasification unit (FSRU), a floating production and remote storage unit (FPSO), and others. Such a tank may also serve as a fuel tank in any type of vessel.

[0043] According to one embodiment, a ship for transporting a liquefied gas comprises a double hull and a aforementioned tank arranged in the double hull.

[0044] According to one embodiment, the invention also provides a transfer system for a liquefied gas, the system comprising the aforementioned ship, insulated pipes arranged to connect the tank installed in the hull of the ship to a floating or land-based storage facility and a pump for driving a flow of fluid / liquefied gas through the insulated pipes from or to the floating or land-based storage facility to or from the tank of the ship.

[0045] According to one embodiment, the invention also provides a method for loading or unloading such a ship, in which a liquefied fluid / gas is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the ship's tank. Brief description of the figures

[0046] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the appended drawings.

[0047] [Fig.l] [Fig.l] is a schematic sectional view of a tank wall of a sealed and thermally insulating tank.

[0048] [Fig.2] [Fig.2] is a partial exploded and perspective view of a caisson ca insulation, the heat-insulating lining having been deliberately omitted from the drawing.

[0049] [Fig.3] [Fig.3] is a schematic view of the tank wall of [Fig.l] with a view to below from the load-bearing wall, the view being centered on a heat-insulating box.

[0050] [Fig.4] [Fig.4] is a partial view, in perspective and from an interior space of the heat-insulating box, of a transverse side panel of the heat-insulating box of [Fig.2] according to a first embodiment.

[0051] [Fig.5] [Fig.5] is a partial view, in section and from above, of the heat-insulating box according to the first embodiment.

[0052] [Fig.5A] [Fig.5A] is a detail of [Fig.5] showing a variant of the first embodiment.

[0053] [Fig.6] [Fig.6] a partial view, in perspective and from an interior space of the heat-insulating box, of a transverse side panel of a heat-insulating box according to a second embodiment.

[0054] [Fig.7] [Fig.7] is a partial view, in section and from above, of the heat-insulating box according to the embodiment of [Fig.6].

[0055] [Fig.8] [Fig.8] is a partial view, in section and from an interior space of the heat-insulating box, of the transverse side panel of a heat-insulating box according to a third embodiment.

[0056] [Fig.9] [Fig.9] is a partial view, in perspective and from an interior space of the heat-insulating box, of a transverse side panel and a longitudinal side panel of a heat-insulating box according to a fourth embodiment.

[0057] [Fig. 10] [Fig. 10] is a view showing various elements of the heat-insulating box according to the embodiment of [Fig.9].

[0058] [Fig. 11] [Fig. 11] is an exploded view of the heat-insulating box according to the embodiment of [Fig.9].

[0059] [Fig. 12] [Fig. 12] is a schematic cutaway representation of a LNG carrier tank and a loading / unloading terminal for this tank. Description of the embodiments

[0060] A sealed and thermally insulating membrane tank for storing liquefied gas is described below. The tank comprises a plurality of tank walls 1.

[0061] A tank wall 1 is shown schematically in section in [Fig.l]. As shown, the tank wall 1 has a multi-layer structure comprising, from the outside to the inside of the tank, a secondary thermally insulating barrier 2 comprising secondary insulating elements 7, resting against a load-bearing wall 3, a secondary sealing membrane 4 resting against the secondary thermally insulating barrier 2, a primary thermally insulating barrier 5 comprising primary insulating elements 8, resting against the secondary sealing membrane 4 and a primary sealing membrane 6 intended to be in contact with the liquefied gas contained in the tank. The primary sealing membrane 6 defines an internal space intended to receive the liquefied gas. By way of example, such membrane tanks are described in particular in patent application FR2877638.

[0062] The load-bearing wall 3 is part of a load-bearing structure, such as the double hull of a ship.

[0063] The liquefied gas intended to be stored in the tank may in particular be a liquefied natural gas (LNG), that is to say a gas mixture comprising mainly methane and one or more other hydrocarbons. Liquefied gas can also be ethane or liquefied petroleum gas (LPG), which is a mixture of hydrocarbons from oil refining, mainly propane and butane.

[0064] The secondary insulating elements 7 take the form of heat-insulating boxes. In [Fig. 2], an exploded view of such a heat-insulating box 7 is shown.

[0065] The heat-insulating box 7 is for example made from wood or composite and has the general shape of a rectangular parallelepiped.

[0066] The heat-insulating box 7 comprises a cover panel 21, a bottom panel 22, and side panels 23, 24.

[0067] The bottom panel 22 is spaced from the cover panel 21 in a vertical direction of the heat-insulating box 7. The vertical direction of the heat-insulating box 7 is parallel to the thickness direction E (see [Fig.l]) of the tank wall 1 when the heat-insulating box 7 is installed in the tank wall 1. In the remainder of this description, for convenience, the vertical direction of the heat-insulating box 7 will therefore be designated by the thickness direction E.

[0068] The side panels 23, 24 extend along the thickness direction E and connect the bottom panel 22 and the cover panel 21 along the edges of the bottom panel 22 and the cover panel 21. Thus, the bottom panel 22, the cover panel 21 and the side panels 23, 24 together delimit an interior space 25 of the heat-insulating box 7.

[0069] The side panels 23, 24 are four in number: two longitudinal side panels 23 and two transverse side panels 24. The longitudinal side panels 23 are parallel to each other and extend in a longitudinal direction L. The transverse side panels 24 are parallel to each other and extend in a transverse direction T. The transverse direction T is orthogonal to the longitudinal direction L. Furthermore, the transverse direction T and the longitudinal direction L are each orthogonal to the thickness direction E.

[0070] The heat-insulating box 7 further comprises longitudinal internal partitions 33 and transverse internal partitions 34. The longitudinal internal partitions 33 extend in the longitudinal direction L and are spaced from each other in the transverse direction T, for example at regular intervals. The transverse internal partitions 34 extend in the transverse direction T and are spaced from each other in the longitudinal direction L.

[0071] The internal partitions 33, 34 extend in planes parallel to the thickness direction E and divide the interior space 25 of the heat-insulating box 7 into a plurality of compartments 26. The compartments 26 receive a heat-insulating lining, which has been deliberately omitted from the drawing of [Fig. 2]. For example, the heat-insulating lining comprises glass wool, cellulose wadding, perlite, aerogels, fumed silica, polymer foam or a combination thereof. The heat-insulating filling may completely fill the compartments 26.

[0072] Furthermore, the internal partitions 33, 34 are in contact against the bottom panel 22 and the cover panel 21.

[0073] The cooperation between the internal partitions 33, 34 and between the internal partitions 33, 34 with the side panels 23, 24 will be detailed below.

[0074] [Fig. 3] is a schematic view of the tank wall 1 seen from below from the load-bearing wall 3, thus making it possible to visualize the secondary thermally insulating barrier 2 and the anchoring thereof on the load-bearing wall 3. A plurality of heat-insulating boxes 7 described previously are juxtaposed on the load-bearing wall 3. More precisely, the heat-insulating boxes 7 are arranged with the same orientation in the plane of the load-bearing wall 3. In order to simplify the drawing and the explanation which follows, only one heat-insulating box 7 has been shown in detail in the center of the drawing of [Fig. 3]. Other adjacent heat-insulating boxes 7 are shown in dotted lines.

[0075] The heat-insulating boxes 7 are anchored to the load-bearing wall 3 at their corners by anchoring members 9. With reference to [Fig. 2], the bottom panel 22 projects beyond each of the two transverse side panels 24, so as to have a rim 22A located outside the interior space 25. A cleat 10 is arranged on each of the ends of the rim 22A. Each cleat 10 of a heat-insulating box 7 cooperates with a respective anchoring member 9, the same anchoring member 9 cooperating with the cleats 10 of a plurality of heat-insulating boxes 7. Shims 11 (shown in [Fig. 3]) are provided to support the heat-insulating boxes 7 at their corners and to level the heat-insulating boxes 7 when they are installed on the load-bearing wall 3.

[0076] In [Fig. 3], there are schematically represented mastic beads 40 by which the bottom panel 22 of the heat-insulating box 7 rests on the load-bearing wall 3. The mastic beads 40 serve to compensate for the deviations of the load-bearing wall 3 with respect to a flat reference surface. In a manner not shown, kraft paper may be interposed between the mastic beads 40 and the load-bearing wall 3 to prevent the mastic beads from adhering to the load-bearing wall 3. Alternatively, the aforementioned kraft paper is omitted and the secondary heat-insulating box 7 is retained on the load-bearing wall 3 at least in part by the adhesion of the mastic beads.

[0077] A first embodiment of the heat-insulating box 7 is shown in Figures 4 and 5. [Fig.4] shows in perspective, from the interior space 25 of the heat-insulating box 7, a transverse side panel 24 together with one of the longitudinal internal partitions 33. [Fig.5] shows a part of this transverse side panel 24 together with other elements of the heat-insulating box 7, in section and in view of above, that is, from the cover panel 21 along the thickness direction E. As in [Fig.2], the heat-insulating lining has been deliberately omitted from the drawing in [Fig.4] and [Fig.5].

[0078] As shown, the side panels 23, 24 and the internal partitions 33, 34 each consist of a plate, for example a wooden plate, in particular plywood.

[0079] The side panels 23, 24 are fixed to each other in various ways as will be detailed below.

[0080] The transverse side panel 24 has a mortise 60 for each of the longitudinal internal partitions 33. It is understood that the other transverse side panel 24 not shown in [Fig.4] may have identical mortises 60. The description which follows is therefore also applicable to this other transverse side panel 24.

[0081] The mortises 60 are formed in the thickness of the transverse side panel 24 in the longitudinal direction L, for example by machining in the transverse side panel 24. Thus, the transverse side panel 24 comprises thickened portions 68 formed in one piece with the transverse side panel 24, each thickened portion 68 extending between two adjacent mortises 60 or between a mortise 60 and a longitudinal side panel 23.

[0082] Each of the mortises 60 extends in a vertical plane, that is to say in a plane parallel to the thickness direction E, and opens into the interior space 25. One end 36 of the longitudinal internal partition 33 is received in the mortise 60 corresponding to this longitudinal internal partition 33. This end 36 is fixed to the transverse side panel 24 in the mortise 60. Preferably, the end 36 is fixed by means of several staples 69, one of which is shown in [Fig. 5]. Preferably in this case, the staples 69 pass through the transverse side panel 24 and are fixed in an end face 36A (see [Fig. 5]) of the longitudinal internal partition 33. In this way, the fixing of the ends 36 in the mortises 60 is easy to achieve. Alternatively, the ends 36 may be secured by screws or nails preferably passing through the transverse side panel 24 and being secured in the end faces 36A.

[0083] Returning to [Fig. 4], the longitudinal internal partitions 33 have a series of notches 54 facing the bottom panel 22. In a manner not shown, the transverse internal partitions 34 each have a series of complementary notches facing the cover panel 21, so that the internal partitions 33, 34 are installed by fitting into the interior space 25 of the heat-insulating box 7. Such types of arrangement with notches are illustrated in patent FR2867831B1, in particular in its figures 2 to 5, 8 and 10. The reference 32 on [Fig. 5] indicates the position of a fitting between a notch 54 of a longitudinal internal partition 33 and a complementary notch of a transverse internal partition 34.

[0084] As mentioned above, the heat-insulating boxes 7 are anchored to the load-bearing wall 3 at their corners by anchoring members 9 cooperating with the cleats 10 arranged on the edges 22A. It has been observed that the transverse side panels 24 are vulnerable to buckling when the compressive forces applied to the heat-insulating box 7 in the thickness direction E, in particular the compressive forces due to the dynamic impacts of the liquefied gas on the tank wall 1, are significant. Fixing the ends 36 of the longitudinal internal partitions 33 in the mortises 60 improves the resistance of the transverse side panels 24 to buckling. Correlatively, this fixing holds the ends 36 of the longitudinal internal partitions 33 in the mortises 60, which also improves the resistance of the longitudinal internal partitions 33 to buckling.

[0085] With reference to [Fig. 5], the transverse side panels 24 preferably have a greater thickness ç, in the longitudinal direction L, which is strictly greater than a greater thickness d, in the transverse direction T, of the longitudinal side panels 23. This further improves the resistance of the transverse side panels 24 to buckling. In one example, ç = 30 or 24 or 21 or 18 or 15 mm, d = 21 or 18 or 15 mm, and m = 18 or 15 or 12 mm where m denotes the thickness, in the transverse direction T, of the longitudinal internal partitions 33.

[0086] In the example shown in [Fig.4] and [Fig.5], the transverse side panel 24 has recesses 24A at its two ends. Each recess 24A receives one end 23A of a longitudinal side panel 23. Thus, the longitudinal side panels 23 can be fixed by their ends 23A to the transverse side panels 24 by means of staples 49, only one of which is shown in [Fig.5], passing through the transverse side panel 24 at the recesses 24A. Thus, it is easy to fix the longitudinal side panels 23 to the transverse side panels 24 despite the thickness of the transverse side panels 24. For example, the recesses 24A are made halfway through the thickness of the transverse side panel 24. Alternatively, the longitudinal side panels 23 can be fixed by screws or nails passing through the recesses 24A.

[0087] In another variant shown in [Fig.5A], the transverse side panel 24 is devoid of the recesses 24A and the longitudinal side panels 23 are fixed by their ends 23A to the transverse side panels 24 by means of staples 491, only one of which is shown in [Fig.5A], passing through the ends 23A. Thus, the staples 491 pass through the longitudinal side panels 23, which are less thick. Alternatively, the longitudinal side panels 23 can be fixed by screws or nails passing through the ends 23A.

[0088] According to still other variants, the fixing of the longitudinal side panels 23 to the transverse side panels 24 is carried out by gluing.

[0089] The transverse internal partitions 34 are fixed to the longitudinal side panels 23. This fixing can be carried out in various ways, for example by means of screws or staples or nails.

[0090] Returning to [Fig. 2], the heat-insulating box 7 may further have through-holes 27 communicating with the interior space 25. The through-holes 27 allow the circulation of an inert gas (for example nitrogen) in the interior space 25, the inert gas serving to place the thermally insulating barrier 2 under an inert atmosphere. The heat-insulating lining described above is in this case permeable to gases. In the example shown, the through-holes 27 are made in the transverse side panels 24. Alternatively, it is also possible to provide the through-holes 27 on the longitudinal side panels 23 and / or on the bottom panel 22.

[0091] A second embodiment of the heat-insulating box 7 is shown in Figures 6 and 7. In these figures, elements similar or identical to those of Figures 1 to 5 bear the same reference signs. It is specified that [Fig.7] is not to scale, the dimensions of certain elements having been exaggerated to ensure the readability of the drawing.

[0092] In this embodiment, the transverse side panel 24 comprises an outer plate 124 and inner plates 128. The inner plates 128 are fixed to the outer plate 124, more precisely on the face of the outer plate 124 which is turned towards the interior space 25 of the heat-insulating box 7. Preferably, the inner plates 128 are fixed by means of staples 129 passing through the outer plate 124, as shown in [Fig. 7]. As for the fixing of the ends 36 in the mortises 60, this fixing is easy to achieve. Alternatively, the inner plates 128 can be fixed to the outer plate 124 in other ways, in particular by means of screws or nails passing through the outer plate 124, or by gluing, or by gluing and stapling. The internal plates 128 and the external plate 124 are, for example, wooden plates, in particular plywood.

[0093] The internal plates 128 are fixed to the external plate 124 in such a way that the facing end faces of two adjacent plates 128 are spaced apart, in the transverse direction T, by a distance s (see [Fig.7]). The distance s is equal, to within manufacturing tolerances, to the thickness m, in the transverse direction T, of the longitudinal internal partitions 33. Thus, said facing end faces and the face of the external plate 124 which is turned towards the interior space 25 together form a mortise 160 similar to the mortises 60 described above. Each of the internal plates 128 extends between two adjacent mortises 160 or between a mortise 160 and a longitudinal side panel 23.

[0094] In this embodiment also, the ends 36 of the longitudinal partitions 33 are fixed in the mortises 160, preferably by means of staples 69, which preferably pass through the external plate 124. Alternatively, the ends 36 can be fixed by screws or nails preferably passing through the transverse side panel 24.

[0095] In this embodiment also, the transverse side panels 24 preferably have a greater thickness Ç, along the longitudinal direction L, which is strictly greater than a greater thickness d, along the transverse direction T, of the longitudinal side panels 23. In one example, Ç = 30 or 24 or 21 or 18 or 15 mm, d = 21 or 18 or 15 mm, and m = 18 or 15 or 12 mm. In a particular embodiment, the internal plates 128 and the external plate 124 have equal thicknesses along the longitudinal direction L, for example equal to 12 mm, which tends to simplify the manufacture of the transverse side panels 24. In another particular embodiment, the internal plates 128 and the external plate 124 respectively have different thicknesses along the longitudinal direction L, for example respectively equal to 9 and 12 mm.

[0096] [Fig. 7] also shows that the longitudinal side panels 23 can be fixed to the transverse side panels 24, more precisely to their external plates 124, by means of staples 149, only one of which is shown in [Fig. 7], passing through the external plates 124. This fixing is easy to achieve due to the moderate thickness of the external plates 124. Alternatively, the longitudinal side panels 23 can be fixed by screws or nails passing through the external plates 124, or even be glued to the external plates 124.

[0097] The internal plates 128 have a dimension along the thickness direction E substantially equal to the distance between the bottom panel 22 and the cover panel 21 along the thickness direction E, and therefore substantially equal to the dimension of the longitudinal internal partitions 33, so as to be in contact against the cover panel 21 and the bottom panel 22 when the heat-insulating box 7 is assembled. This can facilitate the installation of the heat-insulating lining in the compartments 26, in particular if the heat-insulating lining is in the form of glass wool. Indeed, the internal plates 128 then do not form a shoulder likely to hinder the insertion of the glass wool, and the thickness of the internal plates 128 along the longitudinal direction L can be adapted according to the glass wool elements available.

[0098] A third embodiment of the heat-insulating box 7 is shown in [Fig. 8]. In these figures, elements similar or identical to those of Figures 1 to 5 bear the same reference signs. It is specified that [Fig. 8] is not to scale, the di- dimensions of certain elements having been exaggerated to ensure the readability of the drawing.

[0099] This third embodiment differs from the second embodiment in that the internal plates 128 are replaced by cleats 228. The dimension of the cleats 228 in the thickness direction E is strictly less than the distance between the bottom panel 22 and the cover panel 21 in the thickness direction E. Thus, the cleats 228 are spaced from the bottom panel 22 and the cover panel 21. The facing end faces of two cleats 228 are spaced, in the transverse direction T, by the distance s, thus forming the mortises 160 in a manner similar to the second embodiment. Preferably, as shown in [Fig. 8], the cleats 228 are placed at mid-height in the thickness direction E. The orifices 27 are deliberately omitted from the drawing in [Fig.8] and can be placed above or below the cleat 228 according to the thickness direction E.

[0100] The secondary waterproofing membrane 4 can be produced in various ways. According to one embodiment, the secondary waterproofing membrane 4 comprises a continuous sheet of metal strakes with raised edges. The metal strakes are welded by their raised edges to parallel welding supports which are fixed in parallel grooves 21R (see [Fig.2]) formed in the cover panels 21 of the heat-insulating boxes 7. The metal strakes are, for example, made of Invar®: that is to say an alloy of iron and nickel whose coefficient of expansion is typically between 1.2.106 and 2.106 K1.

[0101] The primary thermally insulating barrier 5 can be produced in various ways. According to one embodiment, the thermally insulating barrier 5 comprises a plurality of heat-insulating boxes similar to the heat-insulating boxes 7 juxtaposed with each other and resting on the secondary sealing membrane 4.

[0102] The primary waterproofing membrane 6 can be produced in various ways. According to one embodiment, the primary waterproofing membrane 6 can comprise a continuous layer of metal strakes with raised edges, in a manner similar to the secondary waterproofing membrane 4.

[0103] Alternatively, the tank wall 1 may be a single membrane, i.e. the tank wall 1 may comprise only the thermally insulating barrier 2 and the sealing membrane 4, the sealing membrane 4 being in contact with the liquefied gas.

[0104] A fourth embodiment of the heat-insulating box 7 is shown in Figures 9, 10 and 11. In these figures, elements similar or identical to those of Figures 1 to 5 bear the same reference signs.

[0105] [Fig.9] partially represents a transverse side panel 24 and a longitudinal side panel 23 of the heat-insulating box 7, in perspective from the interior space 25. The transverse side panel 24 has mortises 360 similar to the mortises 60. Furthermore, the longitudinal side panel 23 has mortises 369 similar to the mortises 360, each mortise 369 receiving one end of a transverse internal partition 34 as will be described below. As in the first embodiment, the side panels 24, 23 each consist of a plate, for example a wooden plate, in particular plywood, and the mortises 360, 369 are made in the thickness of the side panels 24, 23.

[0106] As can be seen in [Fig.9], the mortises 360, 369 extend over only a portion of the height of the side panels 24, 23 in the thickness direction E. Thus, the mortises 360, 369 comprise abutment surfaces 360A, 369A located between the cover panel 21 and the bottom panel 22. The abutment surfaces 360A, 369A are horizontal, i.e. included in a horizontal plane which is orthogonal to the thickness direction E. In the example shown, all the abutment surfaces 360A, 369A are included in the same horizontal plane. Alternatively, the abutment surfaces 360A may be included in a first horizontal plane and the abutment surfaces 369A may be included in a second horizontal plane spaced from the first horizontal plane. Alternatively, the abutment surfaces 360A, 369A of a given side panel 24, 23 may be included in different horizontal planes.

[0107] It can also be seen in [Fig.9] that the transverse side panel 24 and the longitudinal side panel 23 have end portions 24F, 23F of complementary shapes, so that the transverse side panel 24 and the longitudinal side panel 23 are held together by shape cooperation.

[0108] As in the embodiments described above, in this fourth embodiment, the transverse side panels 24 preferably have a greater thickness, in the longitudinal direction L, which is strictly greater than a greater thickness, in the transverse direction T, of the longitudinal side panels 23.

[0109] With reference to [Fig. 10], a transverse internal partition 33 comprises a central panel 333 which has, at each of its two ends, a projection 336 intended to be housed in a mortise 360. Similarly, a longitudinal internal partition 34 comprises a central panel 334 which has, at each of its two ends, a projection 339 intended to be housed in a mortise 369. The projections 336, 339 extend over only a portion of the height of the longitudinal internal partitions 33, 34 in the thickness direction E.

[0110] Also seen in [Fig. 10] are the notches 54 of the longitudinal internal partitions 33. The notches 54 are made in the central panel 333. As mentioned above, the transverse internal partitions 34 have notches 53 complementary to the notches 54, so that the internal partitions 33, 34 are installed by fitting into the interior space 25 of the heat-insulating box 7. The transverse internal partitions 34 further comprise shoulders 353, the notches 53 opening into the shoulders 353, and shoulders 359 opposite the shoulders 353 in the thickness direction E. The notches 53, 59 and the shoulders 353, 359 are made in the central panel 334.

[0111] [Fig. 11] shows the internal partitions 33, 34 assembled by interlocking by means of the notches 53, 54 described above.

[0112] For each longitudinal internal partition 33, a longitudinal slat 363 is fitted onto each of the two ends of the central panel 333 in the thickness direction E, by means of a groove included in the longitudinal slat 363. The longitudinal slat 363 fitted on the side of the projections 336 is blocked in translation in the longitudinal direction L by stops 336T included in the projections 336. The longitudinal slats 363 are received in the shoulders 353, 359 of the transverse internal partitions 34.

[0113] Similarly, for each transverse internal partition 34, transverse slats 364 are fitted onto each of the two ends of the central panel 334 in the thickness direction E, by means of a groove included in the transverse slat 364. Each transverse slat 364 abuts against one or two longitudinal slats 363. The transverse slats 364 fitted on the side of the projections 339 are blocked in translation in the transverse direction T by stops 339T included in the projections 339.

[0114] When the heat-insulating box 7 is assembled, the projections 336 are received in the mortises 360 and rest on the horizontal abutment surfaces 360A, and the projections 339 are received in the mortises 369 and rest on the horizontal abutment surfaces 369A. The projections 336, 339 are fixed to the side panels 24, 23 in the mortises 360, 369, preferably by means of staples, which preferably pass through the side panels 24, 23. Alternatively, the projections 336, 339 may be fixed in other ways, including by tacks, screwing, gluing, etc.

[0115] The fixing of the projections 336, 339 in the mortises 360, 369 improves the resistance of the side panels 24, 23 to buckling. Correlatively, this fixing maintains the projections 336, 339 in the mortises 360, 369, which also improves the resistance of the internal partitions 33, 34 to buckling.

[0116] As can be seen in [Fig.9], the mortises 360, 369 have a containing dovetail section, orthogonal to the thickness direction E. The projections 336, 339 therefore have a contained dovetail section, orthogonal to the thickness direction E. These dovetail sections tend to retain the side panels 24, 23 by preventing them from buckling towards the outside of the heat-insulating box 7, in other words in a direction away from the interior space 25 of the heat-insulating box 7. Thus, the resistance of the side panels 24, 23 to buckling is further improved.

[0117] Alternatively, the mortises 360, 369 and the projections 336, 339 may have a rectangular section, orthogonal to the thickness direction E.

[0118] As can be seen in particular in [Fig. 11], the internal partitions 33, 34 provided with the slats 363, 364 have, orthogonally to the thickness direction E, an I-beam cross-section, the slats 363, 364 being in contact with the bottom panel 22 and the cover panel 21 when the heat-insulating box 7 is assembled. The internal partitions 33, 34 provided with the slats 363, 364 thus have further improved resistance to buckling.

[0119] With reference to [Fig. 12], a cutaway view of an LNG carrier ship 70 shows a sealed and thermally insulating tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary sealing membrane intended to be in contact with the LNG contained in the tank, a secondary sealing membrane arranged between the primary sealing membrane and the double hull 72 of the ship, and two thermally insulating barriers arranged respectively between the primary sealing membrane and the secondary sealing membrane and between the secondary sealing membrane and the double hull 72.

[0120] In a manner known per se, loading / unloading pipelines 73 arranged on the upper deck of the ship can be connected, by means of appropriate connectors, to a maritime or port terminal to transfer a cargo of LNG from or to the tank 71.

[0121] [Fig. 12] shows an example of a marine terminal comprising a loading and unloading station 75, an underwater pipeline 76 and an onshore installation 77. The loading and unloading station 75 is a fixed offshore installation comprising a mobile arm 74 and a tower 78 which supports the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading / unloading pipelines 73. The orientable mobile arm 74 adapts to all sizes of LNG carriers. A connecting pipe, not shown, extends inside the tower 78. The loading and unloading station 75 allows the loading and unloading of the LNG carrier 70 from or to the onshore installation 77. The latter comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the underwater pipe 76 to the loading or unloading station 75.The subsea pipeline 76 allows the transfer of liquefied gas between the loading or unloading station 75 and the onshore installation 77 over a long distance, for example 5 km, which makes it possible to keep the LNG carrier 70 at a great distance from the coast during loading and unloading operations.

[0122] To generate the pressure necessary for the transfer of liquefied gas, we use pumps on board the ship 70 and / or pumps equipping the shore installation 77 and / or pumps equipping the loading and unloading station 75.

[0123] Although the invention has been described in connection with several particular embodiments, it is quite obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0124] The use of the verb “comprise”, “comprise” or “include” and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0125] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

Claims

1. A heat-insulating box (7) for a sealed and thermally insulating tank intended to contain a liquefied gas, the heat-insulating box comprising a cover panel (21), a bottom panel (22) spaced from the cover panel (21) in a vertical direction (E), and side panels, the side panels (23, 24) extending in the vertical direction (E) and connecting the bottom panel (22) and the cover panel (21) along the edges of the bottom panel (22) and the cover panel (21) so as to delimit an interior space (25) of the heat-insulating box, the side panels (23, 24) comprising longitudinal side panels (23) and transverse side panels (24), the longitudinal side panels (23) extending in a longitudinal direction (L) and the transverse side panels (24) extending in a transverse direction (T), the transverse direction (T) being orthogonal to the longitudinal direction (L),and the longitudinal direction (L) and the transverse direction (T) being orthogonal to the vertical direction, said heat-insulating box (7) further comprising a plurality of internal partitions (33, 34) arranged in a vertical plane and dividing said interior space (25) into a plurality of compartments (26), the compartments (26) being filled with a heat-insulating lining, the plurality of internal partitions (33, 34) comprising transverse internal partitions (34) extending in the transverse direction (T) and spaced from each other in the longitudinal direction (L), and longitudinal internal partitions (33) extending in the longitudinal direction (L) and spaced from each other in the transverse direction (T), wherein a transverse side panel (24) has mortises (60, 160, 360) extending in a vertical plane and opening into said interior space (25), each called mortise (60, 160, 360) receiving one end (36,336) of a said longitudinal internal partition (33) and said end (36, 336) being fixed to said transverse side panel (24) in said mortise (60, 160, 360).,

2. A heat-insulating box (7) according to claim 1, wherein said transverse side panel (24) comprises spacer portions (68, 128, 228), each said spacer portion extending between two adjacent mortises (60, 160, 360) or between one mortise (60, 160, 360) and a longitudinal side panel (23).

3. A heat-insulating box (7) according to claim 2, wherein the transverse side panel (24) comprises an outer plate (124) and the spacer portions (128, 228) are fixed to the outer plate (124) on a face of the outer plate (124) facing the interior space (25) of the heat-insulating box (7).

4. A heat-insulating box (7) according to claim 3, wherein the spacer portions are internal plates (128) or internal cleats (228).

5. A heat-insulating box (7) according to claim 2, wherein the spacer portions (68) are formed integrally with the transverse side panel (24).

6. A heat-insulating box (7) according to any one of claims 1 to 5, wherein said ends (36, 336) of the longitudinal internal partitions (33) are fixed to said transverse side panel (24) by staples (69), or screws or nails, passing through the transverse side panel (24) and being fixed in end faces of the longitudinal internal partitions (33).

7. Heat-insulating box (7) according to any one of claims 1 to 6, in which the longitudinal internal partitions (33) and the transverse internal partitions (34) are in contact against the cover panel (21) and the bottom panel (22).

8. A heat-insulating box (7) according to claim 7, wherein each longitudinal internal partition (33) comprises a central panel (333) and a projection (336) formed at one end of the central panel (333), each said projection (336) forming a said end of a longitudinal internal partition (33) received in a said mortise (360) and cooperating with a stop surface (360A) that said mortise (360) comprises, the stop surface (360A) being included in a horizontal plane, the horizontal plane being orthogonal to the vertical direction (E) and being located between the cover panel (21) and the bottom panel (22).

9. Heat-insulating box (7) according to claim 8, in which each longitudinal internal partition (33) comprises an upper longitudinal slat (363) fitted onto the central panel (333) and in contact against the cover panel (21), and a lower longitudinal slat (363) fitted onto the central panel (333) and in contact against the bottom panel (22).

10. Heat-insulating box (7) according to any one of claims 1 to 9, in which a longitudinal side panel (23) has additional mortises (369) extending in a vertical plane and opening into said interior space (25), each said additional mortise (369) receiving one end of a said transverse internal partition (34) and said end being fixed to said longitudinal side panel (23) in said additional mortise (369).

11. Heat-insulating box (7) according to claim 10, wherein each transverse internal partition (34) comprises a central panel (336) and an additional projection (339) formed at one end of the central panel (336), each said additional projection (339) forming a said end of a transverse internal partition (34) received in a said additional mortise (369) and cooperating with a stop surface (369A) that said additional mortise (369) comprises, the stop surface (369A) being included in a horizontal plane, the horizontal plane being orthogonal to the vertical direction (E) and being located between the cover panel (21) and the bottom panel (22).

12. A heat-insulating box (7) according to claim 11 taken in combination with claim 9, wherein each transverse internal partition (34) comprises a plurality of upper transverse slats (364) fitted onto the central panel (334) and in contact against the cover panel (21), and a plurality of lower transverse slats (364) fitted onto the central panel (334) and in contact between the bottom panel (22), the upper transverse slats (364) extending between two adjacent upper longitudinal slats (363) or between an upper longitudinal slat (363) and a longitudinal side panel (23), and the lower transverse slats (364) extending between two adjacent lower longitudinal slats (363) or between a lower longitudinal slat (363) and a longitudinal side panel (23).

13. Heat-insulating box according to any one of claims 1 to 12, in which the bottom panel (22) projects beyond said transverse side panel (24) so ​​as to have a rim (22A) located outside the interior space (25) of the heat-insulating box (7), and in which at least one cleat (10) is arranged on the rim (22A).

14. A sealed and thermally insulating tank, integrated into a supporting structure, said tank comprising a tank wall (1) fixed to a supporting wall (3) of the supporting structure, the tank wall comprising in a thickness direction (E), from the outside to the inside of the tank, a thermally insulating barrier (2) retained on the load-bearing wall (3), and a sealing membrane (4) supported by the thermally insulating barrier (2), the thermally insulating barrier comprising a plurality of juxtaposed heat-insulating boxes, in which at least one said heat-insulating box (7) is according to any one of claims 1 to 12 and the vertical direction of said heat-insulating box (7) is parallel to the thickness direction (E).

15. A sealed and thermally insulating tank according to claim 14, in which the thermally insulating barrier (2) is retained on the load-bearing wall (3) by anchoring members (9), said heat-insulating box (7) is according to claim 13 and an anchoring member (9) cooperates with the cleat (10) of said heat-insulating box (7).

16. A vessel (70) for transporting a liquefied gas, the vessel comprising a double hull (72) and a tank (71) according to any one of claims 14 to 15 arranged in the double hull.

17. A transfer system for a liquefied gas, the system comprising a vessel (70) according to claim 16, insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the vessel to a floating or land-based storage facility (77) and a pump for driving a flow of fluid / liquefied gas through the insulated pipes from or to the floating or land-based storage facility to or from the vessel tank.

18. A method of loading or unloading a vessel (70) according to claim 16, wherein a liquefied gas is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or land-based storage facility (77) to or from the tank (71) of the vessel (70).

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