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 bottom panel (22) of the heat-insulating box (7) is supported on a load-bearing wall (3) by means of mastic elements comprising longitudinal rows of mastic (4L) and transverse rows of mastic (4T). Each longitudinal row of mastic (4L) comprises longitudinal mastic portions (43, 143) aligned parallel to a longitudinal direction (L), and each transverse row of mastic (4T) comprises transverse mastic portions (48, 244) aligned parallel to a transverse direction (T). The longitudinal mastic portions (43, 143) are non-contiguous with the transverse mastic portions (48, 244), allowing gas circulation.The longitudinal mastic portions (43, 143) carry longitudinal internal partitions (33) of the heat-insulating box (7), and the longitudinal transverse mastic portions (48, 244) carry transverse internal partitions (34) of the heat-insulating box (7). Figure for abstract: Fig. 3.

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. Mastic beads are arranged between the load-bearing wall and the bottom panel to compensate for deviations of the load-bearing wall from a plane reference.

[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.

[0005] On the other hand, for safety reasons, the thermally insulating barrier must be entirely placed under an inert atmosphere by circulating an inert gas. It is important that there are no spaces inaccessible to the inert gas in which overpressure and / or an accumulation of flammable and / or explosive chemical species could occur. Summary

[0006] 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 receiving a heat-insulating lining, the plurality of internal partitions comprising transverse internal partitions extending in the transverse direction and spaced apart from each other in the longitudinal direction, and longitudinal internal partitions extending in the longitudinal direction and spaced apart from each other in the transverse direction, wherein the bottom panel is coated with mastic elements comprising longitudinal rows of mastic and transverse rows of mastic, each longitudinal row of mastic comprising longitudinal portions of mastic which are aligned parallel to the longitudinal direction, arranged in line with one of said longitudinal internal partitions and each arranged between two adjacent transverse rows of mastic, each transverse row of mastic comprising transverse portions of mastic which are aligned parallel to the transverse direction, arranged in line with one of said transverse internal partitions and each arranged between two adjacent longitudinal rows of mastic, the longitudinal portions of mastic not being joined with the transverse portions of mastic.

[0007] The heat-insulating box is intended to rest on a load-bearing wall of the sealed and thermally insulating tank by means of the mastic elements. The mastic elements are intended to compensate for deviations of the load-bearing wall from a flat reference.

[0008] With this arrangement of the putty elements, the longitudinal putty portions and the transverse putty portions respectively ensure support of the partitions internal longitudinal and internal transverse partitions, which gives the heat-insulating box great resistance to compression forces in the vertical direction.

[0009] Furthermore, the carrying of the longitudinal and transverse internal partitions is at least ensured in the zones between the intersections of the transverse internal partitions with the longitudinal internal partitions, that is to say in zones through which the compressive forces pass the most, in particular when the transverse and longitudinal internal partitions are fitted into one another by notches at the intersections so that there may be play at the said intersections.

[0010] By "non-contiguous" is meant that the longitudinal mastic portions are at a distance from the transverse mastic portions, in other words that there are interstices between the longitudinal mastic portions and the transverse mastic portions. These interstices allow gas to circulate between the back panel and the load-bearing wall, and thus avoid there being spaces inaccessible to the inert gas for the inert atmosphere of the thermally insulating barrier.

[0011] Thus, the resistance of the heat-insulating box to compression forces is improved while ensuring that there are no spaces inaccessible to the inert gas.

[0012] According to embodiments, such a heat-insulating box may comprise one or more of the following characteristics.

[0013] According to one embodiment, the mastic elements are intended to rest on a load-bearing wall.

[0014] According to one embodiment, one of the transverse rows of mastic is arranged in line with each of the transverse internal partitions.

[0015] According to one embodiment, one of the longitudinal rows of mastic is arranged in line with each of the longitudinal internal partitions.

[0016] According to one embodiment, the plurality of internal partitions are in contact against the bottom panel and the cover panel.

[0017] Thus, the carrying of the longitudinal internal partitions and the transverse internal partitions by the longitudinal mastic portions and the transverse mastic portions contributes to the carrying of the cover panel by the internal partitions, which further improves the resistance of the heat-insulating box to compression forces in the vertical direction.

[0018] According to one embodiment, the heat-insulating lining is permeable to gases, and the heat-insulating box comprises through-orifices connecting the interior space of the heat-insulating box with an exterior of the heat-insulating box. Thus, the inert gas can also circulate in the interior space of the heat-insulating box. For example, the through-orifices are provided on the bottom panel and / or on at least one side panel, in particular on at least one transverse side panel.

[0019] According to one embodiment, the longitudinal mastic portions are longitudinal mastic beads extending in the longitudinal direction. According to another embodiment, the longitudinal mastic portions are mastic patches, for example in the shape of a disc or an ellipse. By using such mastic patches instead of mastic beads, it is possible to better control the quantity of mastic used per heat-insulating box.

[0020] According to one embodiment, the mastic elements further comprise external longitudinal mastic beads, each of the external longitudinal mastic beads extending in the longitudinal direction partly in line with a longitudinal side panel.

[0021] The external longitudinal mastic beads provide support for the longitudinal side panels, which further improves the resistance of the heat-insulating box to compression forces in the vertical direction.

[0022] According to one embodiment, the transverse mastic portions are formed by transverse mastic beads extending in the transverse direction.

[0023] According to one embodiment, each of the transverse mastic beads passes under at least one longitudinal internal partition. According to a particular embodiment, each transverse row of mastic is continuous and consists of a transverse mastic bead, so that each of the transverse mastic beads passes under all the longitudinal internal partitions.

[0024] According to one embodiment, the ends of each of the transverse mastic beads are located between two adjacent longitudinal rows of mastic.

[0025] According to one embodiment, the mastic elements further comprise external transverse mastic beads, each of the external transverse mastic beads extending in the transverse direction partly in line with one of the transverse side panels or between a vertical plane in which one of the transverse side panels extends and a vertical plane in which one of the transverse internal partitions extends.

[0026] 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, the bottom panel of said heat-insulating box bearing on the supporting wall by means of the mastic elements of said heat-insulating box and the vertical direction of the heat-insulating box being parallel to the thickness direction.

[0027] Since the heat-insulating box has a high resistance to compressive forces in its vertical direction, the tank wall is able to withstand significant compressive forces in the thickness direction. The cover panel of the heat-insulating box can form a support surface for the waterproofing membrane. In addition, the gaps between the longitudinal mastic portions and the transverse mastic portions are intended to remain after the longitudinal mastic portions and the transverse mastic portions have been crushed onto the load-bearing wall during installation of the heat-insulating box; they then allow gas circulation between the bottom panel and the load-bearing wall, and thus avoid the existence of spaces inaccessible to the inert gas for the inert atmosphere of the thermally insulating barrier.

[0028] 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 a self-supporting tank.

[0029] 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.

[0030] According to one embodiment, a ship for transporting a liquefied gas comprises a double hull and a aforementioned tank arranged in the double hull.

[0031] 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.

[0032] According to one embodiment, the invention also provides a method for loading or unloading such a ship, in which a liquefied gas is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the tank of the ship. Brief description of the figures

[0033] 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.

[0034] [Fig-1] [Fig.l] is a schematic sectional view of a tank wall of a tank waterproof and thermally insulating.

[0035] [Fig.2] [Fig.2] is a partial exploded and perspective view of a heat-insulating box, the heat-insulating lining having been deliberately omitted from the drawing.

[0036] [Fig.3] [Fig.3] is a schematic view of the tank wall of [Fig.l] seen from below from the load-bearing wall, the view being centered on a heat-insulating box.

[0037] [Fig.4] [Fig.4] is a view similar to [Fig.3], showing a first variant embodiment.

[0038] [Fig.5] [Fig.5] is a view similar to [Fig.3], showing a second variant embodiment.

[0039] [Fig.6] [Fig.6] is a view similar to [Fig.3], showing a third variant embodiment.

[0040] [Fig.7] [Fig.7] is a schematic cutaway representation of a LNG carrier tank and a loading / unloading terminal for this tank. Description of the embodiments

[0041] A sealed and thermally insulating membrane tank for storing liquefied gas is described below. The tank comprises a plurality of tank walls 1.

[0042] 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.

[0043] The load-bearing wall 3 is part of a load-bearing structure, such as the double hull of a ship.

[0044] 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. The liquefied gas may also be ethane or a liquefied petroleum gas (LPG), that is to say a mixture of hydrocarbons resulting from the refining of oil comprising essentially propane and butane.

[0045] 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.

[0046] The heat-insulating box 7 is for example made from wood and has the general shape of a rectangular parallelepiped.

[0047] The heat-insulating box 7 comprises a cover panel 21, a bottom panel 22, and side panels 23, 24.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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 lining may completely fill the compartments 26.

[0053] Furthermore, the internal partitions 33, 34 are in contact against the bottom panel 22 and the cover panel 21.

[0054] In one embodiment, the transverse internal partitions 34 each have a series of notches facing the bottom panel 22, and the longitudinal internal partitions 33 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 the patent document FR2867831B1, in particular in its figures 2 to 5, 8 and 10.

[0055] The internal partitions 33, 34 are fixed respectively to the side panels 23, 24. This fixing can be carried out in various ways, for example by means of screws or staples.

[0056] [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.

[0057] 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. 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.

[0058] In [Fig. 3], there are schematically represented mastic beads 43, 44, 45, 46 by which the bottom panel 22 of the heat-insulating box 7 rests on the load-bearing wall 3. The mastic beads 43, 44, 45, 46 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 can be interposed between the mastic beads 43, 44, 45, 46. and the load-bearing wall 3 to prevent adhesion of the mastic beads 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.

[0059] [Fig. 3] also shows the position of the internal partitions 33, 34. The longitudinal internal partitions 33 are marked with dotted lines, and the transverse internal partitions 34 are marked with a phantom line. It should be noted that in [Fig. 3], the dimensions of the internal partitions 33, 34 have been exaggerated to ensure the legibility of the drawing.

[0060] The sealant beads comprise longitudinal sealant beads 43 and transverse sealant beads 44.

[0061] The longitudinal mastic beads 43 extend in the longitudinal direction L. Furthermore, each of the longitudinal mastic beads 43 is arranged in line with a longitudinal internal partition 33. In line with a given longitudinal internal partition 33, the longitudinal mastic beads 43 are aligned parallel to the longitudinal direction L so as to form a longitudinal row of mastic 4L.

[0062] The transverse mastic beads 44 extend in the transverse direction T. Each of the transverse mastic beads 44 is arranged in line with a transverse internal partition 34. Furthermore, each of the transverse mastic beads 44 passes under each of the longitudinal internal partitions 33. Each of the transverse mastic beads 44 thus forms on its own a transverse row of mastic 4T, which is continuous and comprises portions of mastic 48 aligned parallel to the transverse direction T and arranged between two longitudinal rows of mastic 4L.

[0063] The longitudinal mastic beads 43 are each arranged between two transverse rows of mastic 4T. Furthermore, the longitudinal mastic beads 43 are not contiguous with the transverse mastic beads 44. In other words, before and after the longitudinal mastic beads 43 and the transverse mastic beads 44 have been crushed onto the load-bearing wall 3 during the installation of the heat-insulating box 7, the longitudinal mastic beads 43 are at a distance from the transverse mastic beads 44, in other words there remain gaps between the longitudinal mastic beads 43 and the transverse mastic beads 44.

[0064] Since the mastic beads 43, 44 are arranged in line with the internal partitions 33, 34, the mastic beads 43, 44 support the internal partitions 33, 34, which themselves are in contact against the bottom panel 22 and the cover panel 21, and thus support the cover panel 21. The described arrangement of the mastic beads 43, 44 thus ensures support of the internal partitions 33, 34 and the cover panel 21, in all the zones positioned between the intersections of the internal partitions 33, 34, which gives the heat-insulating box 7 a high resistance to compression forces in the thickness direction E.

[0065] In addition, the gaps that remain between the longitudinal mastic beads 43 and the transverse mastic beads 44 allow gas to circulate between the bottom panel 22 and the load-bearing wall 3. When the tank is loaded with liquefied gas, the thermally insulating barrier 2 is placed under an inert atmosphere by circulating an inert gas, such as nitrogen. Said gaps prevent spaces that are inaccessible to the inert gas between the bottom panel 22 and the load-bearing wall 3. In addition, said gaps prevent pockets of gas from remaining trapped between the bottom panel 22, the load-bearing wall 3 and mastic beads 43, 44 after the heat-insulating box 7 has been placed on the load-bearing wall 3.

[0066] Returning to [Fig. 2], the heat-insulating box may further have through-orifices 27 communicating with the interior space 25, to allow the circulation of the inert gas in the interior space 25. The heat-insulating lining described above is in this case permeable to gases. In the example shown, the through-orifices 27 are made in the transverse side panels 24. Alternatively, it is also possible to provide the through-orifices 27 on the longitudinal side panels 23 and / or on the bottom panel 22.

[0067] In the embodiment shown, transverse mastic beads 46, called external, extend in the transverse direction T and are each arranged between a vertical plane in which a transverse side panel 24 extends and a vertical plane in which the transverse internal partition 34 closest to said transverse side panel 24 extends. The longitudinal row of mastic 4L is extended by additional longitudinal mastic beads 45 aligned with the longitudinal mastic beads 43. The additional longitudinal mastic beads 45 are not contiguous with the transverse mastic beads 44 and the external transverse mastic beads 46, which also leaves gaps allowing gas circulation as described above.

[0068] [Fig.4] represents a first variant embodiment of the tank wall 1 described with reference to figures 1, 2 and 3. In this [Fig.4], only the heat-insulating box 7 in the center of [Fig.3] is represented, and the elements similar or identical to those of [Fig.3] bear the same reference signs.

[0069] In this first embodiment, the mastic beads further comprise outer longitudinal mastic beads 47. The outer longitudinal mastic beads 47 extend in the longitudinal direction L and are each arranged between a vertical plane in which a longitudinal side panel 23 extends and the ends of the transverse mastic beads 44. However, as shown in the enlargement on the right of [Fig. 4], each outer longitudinal mastic bead 47 is sufficiently close to the vertical plane of the longitudinal side panel 23 so that, after the mastic beads have been crushed onto the load-bearing wall 3 during of the installation of the heat-insulating box 7, a part of the mastic forming the external longitudinal mastic bead 47 is partly found in line with the longitudinal side panel 23. Thus, the external longitudinal mastic bead 47 ensures a support of the longitudinal side panels 23 which further improves the resistance of the heat-insulating box 7 to compression forces in the thickness direction E. It is preferable that the external longitudinal mastic bead 47 are positioned so that, even after the mastic bead has been crushed on the load-bearing wall 3 during the installation of the heat-insulating box 7, the mastic forming the external longitudinal mastic bead 47 does not overflow from the longitudinal side panels 23. This makes it possible to avoid the undesirable presence of mastic in the space formed between the longitudinal side panels 23 of two adjacent heat-insulating boxes 7.

[0070] Similarly, each outer transverse mastic bead 46 may be sufficiently close to the vertical plane of the longitudinal side panel 23 so that, after the mastic beads have been crushed onto the load-bearing wall 3 during installation of the heat-insulating box 7, a portion of the mastic forming the outer transverse longitudinal mastic bead 46 is partly located in line with the transverse side panel 24. However, it is preferable for the outer transverse mastic beads 46 to be sufficiently distant from the edge 22A of the bottom panel 22 so that, even after the mastic beads have been crushed onto the load-bearing wall 3 during installation of the heat-insulating box 7, the mastic forming the outer transverse mastic beads 46 does not end up under the transverse side panels 24. This makes it possible to avoid the undesirable presence of mastic in the space formed between the transverse side panels. 24 of two adjacent 7 heat-insulating boxes.

[0071] [Fig.5] represents a second variant embodiment of the tank wall 1 described with reference to figures 1, 2 and 3. In this [Fig.5], only the heat-insulating box 7 in the center of [Fig.3] is shown, and elements similar or identical to those of [Fig.3] bear the same reference signs.

[0072] This second embodiment variant differs from the embodiment variant shown in [Fig. 3] in that in the longitudinal rows of mastic 4L, the longitudinal mastic beads 43 are replaced by mastic patches 143, for example disc-shaped. The mastic patches 143 are also non-contiguous with the transverse mastic beads 44. Similarly, the longitudinal mastic beads 45 are replaced by mastic patches 145 non-contiguous with the transverse mastic beads 44 and the outer transverse mastic beads 46. The mastic patches 143, 145 may be disc-shaped as shown in [Fig. 5], for example, or elliptical. By using such mastic patches 143, 145 instead of mastic beads, it is possible to better control the amount of mastic used per heat-insulating box 7.

[0073] It should be noted that the first embodiment variant and the second embodiment variant can be combined, that is to say that the bottom panel 22 of the heat-insulating box 7 can be coated with the mastic portions 143 shown in [Fig. 5] and the external longitudinal mastic beads 47 shown in [Fig. 4].

[0074] [Fig. 6] represents a third variant embodiment of the tank wall 1 described with reference to figures 1, 2 and 3. In this [Fig. 6], only the heat-insulating box 7 in the center of [Fig. 3] is represented, and the elements similar or identical to those of [Fig. 3] bear the same reference signs.

[0075] This third embodiment variant differs from the embodiment variant shown in [Fig. 3] in that the transverse rows of mastic 4T are formed by transverse mastic beads 244 extending in the longitudinal direction L. The transverse mastic beads 244 are aligned parallel to the transverse direction T. Each of the transverse mastic beads 244 is arranged in line with a transverse internal partition 44. The ends of the transverse mastic beads 244 are located between two adjacent longitudinal rows of mastic 4L. For this, for example, the ends of the transverse mastic beads 244 are positioned so that the transverse mastic beads 244 do not pass under the longitudinal internal partitions 33, in other words the transverse rows of mastic 4T are interrupted at the right of each of the longitudinal internal partitions 33.In this embodiment variant also, the longitudinal mastic beads 43 are not joined to the transverse mastic beads 244.

[0076] Optionally, the transverse mastic beads 46 can also each be replaced by transverse mastic beads 246 aligned parallel to the transverse direction T and not passing under the longitudinal internal partitions 33. In this alternative embodiment also, the longitudinal mastic beads 45 are not contiguous with the transverse mastic beads 244, 246.

[0077] It should be noted that the third embodiment variant can be combined with the first embodiment variant and / or the second embodiment variant, that is to say that the bottom panel 22 of the heat-insulating box 7 can be coated with the transverse mastic beads 244, 246 shown in [Fig. 6], the mastic portions 143 shown in [Fig. 5] and / or the external longitudinal mastic beads 47 shown in [Fig. 4].

[0078] It should further be noted that, as a variant, the transverse rows of mastic 4T shown in FIGS. 3, 4 and 5 may be interrupted at one or more of the longitudinal internal partitions 33, so that the transverse mastic beads 44 pass under only some of the longitudinal internal partitions 33. In this case, the transverse rows of mastic 4T comprise several transverse mastic beads 44 aligned parallel to the direction transverse T, in a similar manner to the transverse mastic beads 244. The same may apply to the external transverse mastic beads 46 shown in Figures 3, 4 and 5.

[0079] The mastic beads or patches which have just been described serve to compensate for the deviations of the load-bearing wall 3 relative to a flat reference surface, as mentioned above. It should therefore be noted that the dimensions of the mastic beads 43, 44, 45, 46, 47, 244, 246 and of the mastic patches 143, 145, in particular their thicknesses along the thickness direction E, may vary from one heat-insulating box 7 to another on the tank wall 1.

[0080] The mastic beads 43, 44, 45, 46, 47, 244, 246 can be laid in various ways. Preferably, the mastic beads 43, 44, 45, 46, 47, 244, 246 are placed on the bottom panel 22 of the heat-insulating box 7 before the heat-insulating box 7 is placed on the load-bearing wall 3. Alternatively, the mastic beads 43, 44, 45, 46, 47, 244, 246 are first placed on the load-bearing wall 3 before the heat-insulating box 7 is placed. The same applies to the mastic patches 143, 145. The mastic beads 43, 44, 45, 46, 47, 244, 246 can be dimensioned and manufactured as described in WO 2020 / 193584 A1 for example.

[0081] Thanks to the mastic beads or patches, the cover panels 21 of the heat-insulating boxes 7 juxtaposed on the load-bearing wall 3 form a flat support surface for the secondary waterproofing membrane 4.

[0082] 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, or of an alloy of iron and manganese whose coefficient of expansion is typically between 7.106 and 10.106 K1.

[0083] 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.

[0084] The primary waterproofing membrane 6 can be produced in various ways. According to one embodiment, the primary waterproofing membrane 6 can comprise a continuous sheet of metal strakes with raised edges, in a manner similar to the secondary waterproofing membrane 4 both in terms of shape and type of metallic material.

[0085] 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.

[0086] With reference to [Fig.7], 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.

[0087] In a manner known per se, loading / unloading pipes 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.

[0088] [Fig.7] represents an example of a maritime 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 underwater 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.

[0089] To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and / or pumps equipping the onshore installation 77 and / or pumps equipping the loading and unloading station 75 are used.

[0090] 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.

[0091] The use of the verb “comporter”, “comprendre” or “include” and its forms conjugated does not exclude the presence of other elements or other steps than those set out in a claim.

[0092] 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 (7) comprising a cover panel (21), a bottom panel (22) spaced from the cover panel (21) in a vertical direction, and side panels (23, 24), 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) receiving 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 the bottom panel (22) is coated with mastic elements comprising longitudinal rows of mastic (4L) and transverse rows of mastic (4T),each longitudinal row of mastic (4L) comprising longitudinal mastic portions (43, 143) which are aligned parallel to the longitudinal direction (L), arranged in line with one of said longitudinal internal partitions (33) and each arranged between two adjacent transverse rows of mastic (4T), each transverse row of mastic (4T) comprising transverse mastic portions (44, 48, 244) which are aligned parallel to the, transverse direction (T), arranged in line with one of said transverse internal partitions (34) and each arranged between two adjacent longitudinal rows of mastic (4L), the longitudinal mastic portions (43, 143) being non-contiguous with the transverse mastic portions (44, 48, 244).

2. A heat-insulating box (7) according to claim 1, wherein the plurality of internal partitions (33, 34) are in contact against the bottom panel (22) and the cover panel (21).

3. Heat-insulating box (7) according to any one of claims 1 to 2, in which the longitudinal mastic portions are longitudinal mastic beads (43) extending in the longitudinal direction (L).

4. A heat-insulating box (7) according to any one of claims 1 to 2, wherein the longitudinal mastic portions are mastic patches (143).

5. Heat-insulating box (7) according to any one of claims 1 to 4, in which the mastic elements further comprise external longitudinal mastic beads (47), each of the external longitudinal mastic beads (47) extending in the longitudinal direction (L) partly in line with one of the longitudinal side panels (23).

6. Heat-insulating box (7) according to any one of claims 1 to 5, in which the transverse mastic portions are formed by transverse mastic beads (44, 244) extending in the transverse direction (T).

7. Heat-insulating box (7) according to claim 6, in which each of the transverse mastic beads (44) passes under at least one longitudinal internal partition (33).

8. A heat-insulating box (7) according to claim 6, wherein the ends of each of the transverse mastic beads (244) are located between two adjacent longitudinal rows of mastic (4L).

9. A heat-insulating box (7) according to any one of claims 1 to 8, wherein the mastic elements further comprise external transverse mastic beads (46), each of the external transverse mastic beads (46) extending in the transverse direction (T) partly in line with one of the transverse side panels (24) or between a vertical plane in which one of the transverse side panels (24) extends and a vertical plane in which one of the transverse internal partitions (34) extends.

10. 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 supporting 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 is according to any one of claims 1 to 9, the bottom panel (22) of said heat-insulating box (7) bearing on the supporting wall (3) by means of the mastic elements of said heat-insulating box and the vertical direction of the heat-insulating box (7) being parallel to the thickness direction (E).

11. A vessel (70) for transporting a liquefied gas, the vessel comprising a double hull (72) and a tank (71) according to claim 10 disposed in the double hull.

12. A transfer system for a liquefied gas, the system comprising a vessel (70) according to claim 11, 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 liquefied gas through the insulated pipes from or to the floating or land-based storage facility to or from the vessel tank.

13. A method of loading or unloading a vessel (70) according to claim 11, 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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