Patent Application
20180073678
The invention relates to the field of the tanks, which are sealed and thermally insulating, with membranes, for the storage and/or transportation of fluid, such as a cryogenic fluid.
Sealed and thermally insulating tanks with membranes are employed in particular for the storage of liquefied natural gas (LNG), which is stored, at atmospheric pressure, at approximately −162° C.
The document WO-A-2011/157915 describes a sealed and thermally insulating tank for the storage of liquefied natural gas, of the type which comprises a tank wall fixed to a flat bearing wall. The tank wall comprises a primary sealing membrane and a thermally insulating barrier disposed between the bearing structure and the primary sealing membrane. The primary sealing membrane essentially consists of a plurality of corrugated metal sheets tightly welded to one another which form a first series of equidistant parallel rectilinear corrugations extending in a first direction of the plane of the bearing wall and a second series of equidistant parallel rectilinear corrugations extending in a second direction of the plane of the bearing wall, the second direction being at right angles to the first direction, the distance between two adjacent corrugations of the first series and the distance between two adjacent corrugations of the second series being equal to a predetermined corrugation interval. The corrugated metal sheets have rectangular forms whose sides are parallel to, respectively, the first direction and the second direction of the plane of the bearing wall and whose dimensions are substantially equal to integer multiples of the corrugation interval, each edge of a corrugated metal sheet being situated between two adjacent corrugations parallel to said edge.
WO-A-2011/157915 proposes structures that allow the passage of a support foot through the bottom wall of the tank. However, when a diameter of the support foot exceeds two corrugation intervals, these structures provide for locally shifting the routing of the corrugations to form more complex networks of corrugations. Now, increasing the complexity of the network of corrugations in this way can prove complicated to implement, particularly in the case where the routing of the corrugations has an effect on other elements of the tank wall, which must then be adapted to the more complex networks of corrugations. These considerations notably come into play when seeking to design the secondary membrane disposed between the primary insulating barrier and the secondary insulating barrier in the form of a corrugated metal membrane.
Similar problems are also likely to arise in the top wall of the tank, for example in a vapor-collecting duct or in the bottom wall of the tank, for example in a sump structure or any other element passing through a singular zone of the tank wall.
One idea on which the invention is based is to propose a tank wall with a multilayer structure equipped with a through-element passing through a singular zone of the tank wall and in which the structure of the tank wall in said singular zone is simple and connects easily to the adjacent zones of the tank wall.
For that, the invention provides a sealed and thermally insulating tank, said tank comprising a tank wall fixed to a flat bearing wall, the tank wall comprising at least one sealing membrane and at least one thermally insulating barrier disposed between the bearing structure and the sealing membrane,
the or each sealing membrane essentially consisting of a plurality of corrugated metal sheets tightly welded to one another which form a first series of equidistant parallel rectilinear corrugations extending in a first direction of the plane of the bearing wall and a second series of equidistant parallel rectilinear corrugations extending in a second direction of the plane of the bearing wall, the second direction being at right angles to the first direction, the distance between two adjacent corrugations of the first series and the distance between two adjacent corrugations of the second series being equal to a predetermined corrugation interval io, the corrugated metal sheets having rectangular forms whose sides are parallel to, respectively, the first direction and the second direction of the plane of the bearing wall and whose dimensions are substantially equal to integer multiples of the corrugation interval, each edge of a corrugated metal sheet being situated between two adjacent corrugations parallel to said edge, the or each thermally insulating barrier essentially consisting of a plurality of juxtaposed insulating panels each having an inner face which forms a support surface for the sealing membrane, the insulating panels having rectangular parallelepipedal forms whose sides are parallel to, respectively, the first direction and the second direction of the plane of the bearing wall and whose dimensions in projection in the plane of the bearing wall are substantially equal to integer multiples of the corrugation interval,
metal anchor plates being fixed onto the inner faces of the insulating panels and the corrugated metal sheets having edges welded to said anchor plates to retain the sealing membrane against said support surface,
the sealed tank being equipped with a through-element passing through the tank wall.
According to one embodiment, the corrugations of the primary sealing membrane are offset by a half-corrugation interval in each of the two directions of the plane in relation to the corrugations of the secondary sealing membrane,
the corrugated metal sheets of the primary sealing membrane are interrupted at an opening, said opening interrupting two corrugations of each series of corrugations of the primary sealing membrane, said opening being centered at a position situated in the middle of the two interrupted corrugations of each series of corrugations of the primary sealing membrane, and the corrugated metal sheets of the secondary sealing membrane are interrupted at an opening, said opening interrupting a sequence of three corrugations of each series of corrugations of the secondary sealing membrane, said opening of the secondary sealing membrane being concentric with the opening of the primary sealing membrane, said opening of the secondary sealing membrane being centered at a position situated at the intersection of the second corrugation of the sequence of three corrugations belonging to the first series of the secondary sealing membrane and of the second corrugation of the sequence of three corrugations belonging to the second series of the secondary sealing membrane.
According to one embodiment, the or one of the thermally insulating barrier(s) around the or one of the through-elements comprises a plurality of insulating panels which form a ring of square form around the through-element, said ring having outer sides measuring substantially 9io which are parallel to, respectively, the first direction and the second direction of the plane of the bearing wall, said ring delimiting, at its center, a square window whose sides measure substantially 3io and which are also parallel to, respectively, the first direction and the second direction of the plane of the bearing wall, such that the through-element passes through the thermally insulating barrier in said square window,
a first plurality of anchor plates being disposed on the inner face of said ring along the four outer sides of said ring, the distance between each anchor plate of the first plurality and the outer side that it rungs along being equal to the corrugation interval,
link parts linked tightly to the through-element being disposed in the square window around the through-element on the inner face of the insulating panels which form the ring.
According to one embodiment, the corrugated metal sheets of the or one of the sealing membrane(s) around the through-element comprise: two notched rectangular metal plates 3io wide in the first direction and 7io long in the second direction, which are symmetrical to one another in relation to an axis of symmetry parallel to the second direction passing through the center of the square window, called second axis of symmetry, each notched rectangular metal plate having three outer edges disposed in line with the first plurality of anchor plates and welded onto the first plurality of anchor plates and an inner edge having a notch formed to avoid cutting said square window, said notch having a width equal to 1io in the first direction and a length equal to 3io in the second direction so that the notched portion of the inner edge runs along the square window,
and two metal retrofit plates disposed between the non-notched portions of the inner edges of the two notched rectangular metal plates, the two metal retrofit plates being symmetrical to one another in relation to an axis of symmetry parallel to the first direction passing through the center of the square window, called first axis of symmetry, each metal retrofit plate being 1 io wide in the first direction and 2io long in the second direction and having a corrugation aligned on said second axis of symmetry,
the two longitudinal edges of each metal retrofit plate being tightly welded to the inner edges of the two notched rectangular metal plates, and the outer lateral edge of each metal retrofit plate being welded to the anchor plates of the first plurality,
the notched portion of the inner edge of each notched rectangular metal plate and the inner lateral edge of each metal retrofit plate being tightly welded to said link parts.
By virtue of these features, it is possible to allow the passage of a through-element that is relatively bulky, namely having a diameter of up to 3io, while avoiding the concentrations of strains in the sealing membrane around the through-element. Indeed, this very symmetrical design of the sealing membrane makes it possible to stress the different corrugations in a fairly balanced way to take up the deformations caused by the thermal and mechanical stresses. Furthermore, by providing a symmetrical zone of the thermally insulating barrier with dimensions of 9io by 9io, this structure is relatively easy to connect to the adjacent zones of the tank wall, in particular when the latter are formed by insulating panels with dimensions of 3io by 9io. Finally, by providing a zone of the sealing membrane with dimensions of 7io by 7io that is symmetrical and concentric with the zone of the thermally insulating barrier, this structure creates an offset between the edges of the insulating panels and the edges of the corrugated metal sheets of the sealing membrane, which also simplifies the connection to the adjacent zones of the tank wall, where it is generally necessary for a corrugated metal sheet to overlap several insulating panels.
The link parts which are disposed in the square window between the metal plate to whose inner edges they are welded and the through-element to which they are tightly linked can be arranged in many ways.
In one embodiment, these link parts comprise a tray parallel to the bearing wall linked to the periphery of the through-element and extending around the main body at the same level at the inner face of the ring, and closure plates whose inner edges are welded onto this tray. Other configurations are possible to produce the sealing around the through-element, for example by means of a flange borne by the through-element and whose downward-facing edge is welded onto one or more metal closure plates surrounding the through-element. A sealed link using such a flange between a metal membrane and a rod passing through this membrane is for example illustrated in FR-A-2973098 or FR-A−2413260.
According to other advantageous embodiments, such a sealed and thermally insulating tank can have one or more of the following features.
According to one embodiment, said thermally insulating barrier is a secondary thermally insulating barrier retained against the bearing structure, and said sealing membrane is a secondary sealing membrane borne by the secondary thermally insulating barrier, the tank wall further comprising a primary thermally insulating barrier resting against the secondary sealing membrane and a primary sealing membrane borne by the primary thermally insulating barrier and intended to be in contact with the fluid contained in the tank.
According to embodiments, the through-element can comprise a support foot for a piece of equipment intended to be placed in the tank, or a sealed duct defining a passage between the interior space of the tank and the outside of the tank, or even a sump structure.
Such a tank can form part of an onshore storage installation, for example for storing LNG, or be installed in a coastal or deep-water floating structure, in particular a methane or ethane tanker, a floating storage and regasification unit (FSRU), an offshore floating production and storage unit (FPSO) and the like.
According to one embodiment, a ship for transporting a fluid comprises a double hull and an abovementioned tank disposed in the double hull.
According to one embodiment, the invention also provides a method for loading or unloading such a ship, in which a fluid is routed through insulated pipelines from or to a floating or onshore storage installation to or from the tank of the ship.
According to one embodiment, the invention also provides a transfer system for a fluid, the system comprising the abovementioned ship, insulated pipelines arranged so as to link the tank installed in the hull of the ship to a floating or onshore storage installation and a pump for driving a fluid through the insulated pipelines from or to the floating or onshore storage installation to or from the tank of the ship.
Some aspects of the invention are based on the idea of providing a multilayer wall structure implementing, to the greatest possible extent, the following construction principles:
The invention will be better understood, and other aims, details, features and advantages thereof will become more clearly apparent from the following description of several particular embodiments of the invention, given purely in an illustrative and nonlimiting manner, with reference to the attached drawings.
By convention, the terms “outer” and “inner” are used to define the relative position of one element in relation to another, by reference to the interior and the exterior of the tank. Furthermore, the longitudinal direction of a rectangular parallelepipedal element should be understood to be the direction corresponding to the side of greatest dimension of the rectangle.
In relation to
The bearing wall 3 can in particular be a self-supporting metal sheet or, more generally, any type of rigid partition exhibiting appropriate mechanical properties. The bearing wall 3 can notably be formed by the hull or the double hull of a ship. As sketched in
The secondary thermally insulating barrier 1 comprises a plurality of insulating panels 2 anchored to the bearing wall 3 by means of beads of resin, not illustrated, and/or studs 8 welded to the bearing wall 3. The insulating panels 2 have a substantially rectangular parallelepipedal form.
As illustrated in
In a standard zone of a wall, as represented in
As represented in
The grooves 14, 15 pass right through the thickness of the inner plate 10 and thus emerge at the layer of insulating polymer foam 9. Moreover, the insulating panels 2 comprise, in the zones of intersection between the grooves 14, 15, clearance orifices 16 formed in the layer of insulating polymer foam 9. The clearance orifices 16 provide a housing for the node zones, formed at the intersections between the corrugations of the metal sheets of the secondary sealing membrane 4.
Moreover, the inner plate 10 is equipped with metal mounting plates 17, 18 for anchoring the edge of the corrugated metal sheets of the secondary sealing membrane 4 on the insulating panels 2. The metal mounting plates 17, 18 extend in two directions at right-angles to each other which are each parallel to two opposing sides of the insulating panels 2. The metal mounting plates 17, 18 are fixed onto the inner plate 10 of the insulating panel 2, by screws, rivets, or staples, for example. The metal mounting plates 17, 18 are placed in voids formed in the inner plate 10 such that the inner surface of the metal mounting plates 17, 18 is flush with the inner surface of the inner plate 10.
The inner plate 10 is also equipped with threaded studs 19 protruding toward the interior of the tank, and intended to ensure the fixing of the primary thermally insulating barrier 5 onto the insulating panels 2 of the secondary thermally insulating barrier 1. On each insulating panel 2, three studs 19 are placed along the longitudinal line formed by the mounting plates 17, namely one stud 19 is placed at the intersection between the line formed by the mounting plates 17 and the line formed by the mounting plates 18 and two studs are placed equidistantly on either side thereof.
In order to ensure the fixing of the insulating panels 2 to the studs 8 fixed to the bearing wall 3, the insulating panels 2 are provided with cylindrical wells 20, represented in
Moreover, the inner plate 10 has, along its edges, in each interval between two successive grooves 14, 15, a setback receiving bridging plates 22 which are each disposed straddling between two adjacent insulating panels 2, astride the interstice 12 between the insulating panels 2. Each bridging plate 22 is fixed against each of the two adjacent insulating panels 2 so as to oppose their mutual separation. The bridging plates 22 have a rectangular parallelepipedal form and, for example, consist of a plate of plywood. The outer face of the bridging plates 22 is fixed against the bottom of the setbacks 21. The depth of the setbacks 21 is substantially equal to the thickness of the bridging plates 22 such that the inner face of the bridging plates 22 comes substantially level with the other flat zones of the inner plate 10 of the insulating panel. Thus, the bridging plates 22 are able to ensure a continuity in the bridging of the secondary sealing membrane 4.
So as to ensure a good distribution of the link loads between the adjacent panels, a plurality of bridging plates 22 extends along each edge of the inner plate 10 of the insulating panels 2, a bridging plate 22 being disposed in each interval between two neighboring grooves 14, 15 of a series of parallel grooves. The bridging plates 22 can be fixed against the inner plate 10 of the insulating panels 2 by any appropriate means. It has, however been found that the combination of the application of a glue between the outer face of the bridging plates 22 and the inner plate 10 of the insulating panels 2 and the use of mechanical fixing members, such as staples, making it possible to apply pressure to the bridging plates 22 against the insulating panels 2, was particularly advantageous.
The secondary sealing membrane 4 comprises a plurality of corrugated metal sheets 24 each having a substantially rectangular form of dimensions equal to the dimensions of an insulating panel 2. The corrugated metal sheets 24 are disposed in an offset manner in relation to the insulating panels 2 of the secondary thermally insulating barrier 1 such that each of said corrugated metal sheets 24 extends jointly over four adjacent insulating panels 2. Each corrugated metal sheet 24 has a first series of parallel corrugations 25 extending in a first direction and a second series of parallel corrugations 26 extending in a second direction. The directions of the series of corrugations 25, 26 are at right angles. Each of the series of corrugations 25, 26 is parallel to two opposing edges of the corrugated metal sheet 24. The corrugations 25, 26 protrude toward the outside of the tank, that is to say in the direction of the bearing wall 3. The corrugated metal sheet 24 comprises, between the corrugations 25, 26, a plurality of flat surfaces. At each intersection between two corrugations 25, 26, the metal sheet comprises a node zone having a peak protruding toward the outside of the tank. The corrugations 25, 26 of the corrugated metal sheets 24 are housed in the grooves 14, 15 formed in the inner plate 10 of the insulating panels 2. The adjacent corrugated metal sheets 24 are welded together with overlap. The anchoring of the corrugated metal sheets 24 onto the metal mounting plates 17, 18 is done by spot welds.
The corrugated metal sheets 24, comprise, along their longitudinal edges and in their four corners, cutouts 28 allowing the passage of the studs 19 intended to ensure the fixing of the primary thermally insulating barrier 5 onto the secondary thermally insulating barrier 1. Two cutouts 28 are situated along each longitudinal edge, respectively at one third and two thirds of the length of the corrugated metal sheet 24.
The corrugated metal sheets 24 are, for example, produced in Invar®: that is to say an alloy of iron and nickel whose expansion coefficient is typically between 1.2×10-6 and 2×10-6 K-1, or in an alloy of iron with high manganese content whose expansion coefficient is typically of the order of 7×10-6 K-1. Alternatively, the corrugated metal sheets 24 could also be produced in stainless steel or in aluminum.
The primary thermally insulating barrier 5 comprises a plurality of insulating panels 6 of substantially rectangular parallelepipedal form having dimensions equal to the dimensions of an insulating panel 2, apart from the thickness which can be different, preferably smaller than that of the insulating panel 2. The insulating panels 6 are here offset in relation to the insulating panels 2 of the secondary thermally insulating barrier 1 such that each insulating panel 6 extends over four insulating panels 2 of the secondary thermally insulating barrier 1. In a standard zone, the insulating panels 6 of the primary thermally insulating barrier 5 and the insulating panels 2 of the secondary thermally insulating barrier 1 are oriented such that the longitudinal directions of the insulating panels 2, 6 are parallel to one another.
The insulating panels 6 comprise a structure similar to that of the insulating panels 2 of the secondary thermally insulating barrier 1, namely a sandwich structure consisting of a layer of insulating polymer foam sandwiched between two rigid plates, for example of plywood. The inner plate 30 of an insulating panel 6 of the primary thermally insulating barrier 5 is equipped with metal mounting plates 32, 33 for anchoring the corrugated metal sheets of the primary sealing membrane 7. The metal mounting plates 32, 33 extend along two right-angled rows which are each parallel to two opposing edges of the insulating panel 6. The metal mounting plates 32, 33 are fixed in voids formed in the inner plate 30 of the insulating panel 6 and fixed thereto, by screws, rivets or staples for example.
Moreover, the inner plate 30 of the insulating panel 6 is provided with a plurality of relaxation slits 34 allowing the primary sealing membrane 7 to be deformed without imposing excessive mechanical strains on the insulating panels 6. Such relaxation slits are in particular described in the document FR 3001945.
The fixing of the insulating panels 6 of the primary thermally insulating barrier onto the insulating panels 2 of the secondary thermally insulating barrier is ensured by means of threaded studs 19. For this, each insulating panel 6 comprises a plurality of cutouts 35 along its edges and in its corners, inside which extends a threaded stud 19. The outer plate of the insulating panels 2 overhangs into the cutouts 35 so as to form a bearing surface for a retaining member which comprises a threaded bore threaded onto each threaded stud 19. The retaining member comprises lugs housed inside the cutouts 35 and coming to bear against the portion of the outer plate overhanging into the cutout 35 so as to sandwich the outer plate between a lug of the retaining member and an insulating panel 2 of the secondary thermally insulating barrier 1 and thus ensure the fixing of each insulating panel 6 onto the insulating panels 2 that it overlaps.
The primary thermally insulating barrier 5 comprises a plurality of closure plates 38 making it possible to complete the bearing surface of the primary sealing membrane 7 at the cutouts 35.
The primary sealing membrane 7 is obtained by assembling a plurality of corrugated metal sheets 39. Each corrugated metal sheet 39 has a substantially rectangular form of dimensions equal to the dimensions of an insulating panel 2 or 6. Each corrugated metal sheet 39 comprises a first series of so-called top parallel corrugations 40, extending in a first direction corresponding to the greatest dimension of the corrugated metal sheet, and a second series of so-called bottom parallel corrugations 41, extending in a second direction at right angles to the first series. The corrugations 40, 41 protrude toward the interior of the tank. The corrugated metal sheets 39 are, for example, produced in stainless steel or in aluminum. In an embodiment not illustrated, the first and second series of corrugations have identical heights.
Each corrugated metal sheet 39 is placed straddling over four insulating panels 6 such that each edge of the corrugated metal sheet 39 covers a row of metal mounting plates 32 or 33 borne by the underlying panel 6. The adjacent corrugated metal sheets 39 are welded to one another with overlap. The anchoring of the corrugated metal sheets 39 onto the metal mounting plates 32 and 33 is done by spot welds.
Preferably, each edge of a corrugated metal sheet 24 or 39 is situated substantially mid-way between two parallel adjacent corrugations of the secondary, respectively primary, membrane. This position of the sheet edge can be modified locally to make fine adjustments.
Referring to
More specifically, the ring of square form of the thermally insulating barrier 1 consists of two long insulating panels 2a and 2b having a width of 3io in the first direction X and a length of 9io in the second direction Y and two short insulating panels 2c and 2d having a width of 3io in the first direction and a length of 3io in the second direction. The long insulating panels 2a and 2b are disposed in the alignment of one another in the first direction X spaced apart by a distance of 3io in the first direction X to delimit the square window 51 in the first direction. The short insulating panels 2c and 2d are disposed between the two long insulating panels 2a and 2b in the alignment of one another in the second direction Y and spaced apart by a distance of 3io in the second direction Y to delimit the square window 51 in the second direction Y.
By virtue of this arrangement, the thermally insulating barrier consists entirely of rows of insulating panels having a width of 3io in the first direction, which facilitates the connection to the adjacent zones of the tank wall, given that such rows exist also in the standard zone of the tank wall.
The support foot 50 will now be described more specifically with reference to
More specifically, the main body 52 here has a form of revolution with circular section, with a tapered bottom part 52a which is connected at its end of smallest diameter 52c to a cylindrical upper part 52b. The base of largest diameter of the tapered part 52a bears against the bearing wall 3. The tapered part 52a extends right through the thickness of the tank wall beyond the level of the primary sealing barrier 7.
The trays 53 and 54 can have different forms. Here, the tray 53 has a square form fitted to the window 51 with a mounting play, whereas the tray 54 has a circular form of smaller diameter.
The tray 53 is extended, inside the tapered bottom part 52a, by an inner tray 53a which separates the interior space of the tapered bottom part 52a into a secondary portion 55 and a primary portion 56. Similarly, the tray 54 is extended, inside the tapered bottom part 52a, by an inner tray 54a which separates the primary portion 56 from an end portion 57 communicating with the interior space of the tank. The secondary 55 and primary 56 portions of the interior space of the main body 52 are filled with non-structural insulating materials such as glass wool, to limit the conduction of heat. A non-structural insulating packing 58 is also arranged between the tray 54 and the tray 53. Similarly, to complete the secondary insulating barrier around the main body 52, insulating blocks with sandwich structure 60, having a flat section in right-angled triangle form, are positioned under the four corners of the tray 53 between the tray 53 and the bearing wall 3 as well as non-structural insulating packings 59.
Preferably, as in the standard zone of the tank wall, each of these secondary insulating panels 2a, 2b, 2c, 2d is associated with the adjacent secondary insulating panels via a plurality of bridging elements 22, represented in
The tray 53 of the through-element having a square form has a setback 61 along the outer edges of its four sides. The insulating panels 2a, 2b, 2c and 2d have setbacks 62 along the four inner edges of the square ring. Bridging elements 63 are disposed straddling over the insulating panels 2a, 2b, 2c and 2d and the tray 53, the bridging elements 63 being placed on the bottom of the setbacks 61 of the tray 53 on one side and of the setbacks 62 of the insulating panels 2a, 2b, 2c and 2d on the other side. The thickness of the bridging elements 63 is substantially equal to the depth of said setbacks so as to offer a flat support surface for closure plates, belonging to the secondary sealed membrane as will be described below.
The bridging elements 63 are preferably simply placed without being linked to the tray 53 or to the insulating panels 2a, 2b, 2c and 2d. This absence of link allows a slight mobility of the bridging elements 63 in response to the differences of thermal deformation between the insulating panels 2a, 2b, 2c and 2d and the support foot 50.
As can be seen in
Referring to
The corrugated metal sheets of the secondary sealing membrane 4 also comprise two metal retrofit plates 24c and 24d disposed between the non-notched portions 29b of the inner edges of the two notched rectangular metal plates 24a and 24b. The two metal retrofit plates 24c and 24d are symmetrical to one another in relation to an axis of symmetry A parallel to the first direction passing through the center of the square window, called first axis of symmetry. Each metal retrofit plate 24c, 24d is 1 io wide in the first direction X and 2io long in the second direction Y and has a corrugation 25a aligned on said second axis of symmetry B.
The two longitudinal edges of each metal retrofit plate 24c, 24d are tightly welded to the inner edges 29b of the two notched rectangular metal plates 24a and 24b and the outer lateral edge of each metal retrofit plate 24c, 24d is welded to the anchor plates of the first plurality 18a and 18b.
Finally, the notched portion 29a of the inner edge of each notched rectangular metal plate 24a and 24b and the inner lateral edge of each metal retrofit plate 24c and 25d are tightly welded to link parts which will be described later.
As can be seen in
Returning to
By virtue of these features, the corrugation borne by each metal retrofit plate 24c, 24d along the second axis of symmetry B is not blocked on both sides and can therefore work in response to the thermal and mechanical strains. The metal retrofit plates 24c and 24d thus prolong the second notched rectangular metal plate 24b in the first direction. The row of anchor plates 17c is symmetrical in relation to the first axis of symmetry A.
As can be seen in
Returning to
The closure plates 64a and 64b here have respective dissymmetrical C and D forms. The closure plates can be cut out in different ways to tightly link the corrugated metal sheets 24a, 24b 24c, 24d to the tray 53 all around the main body 52.
A plurality of metal end parts 65 are welded to the closure plates 64a and 64b and disposed at the intersections between the second edge of each closure plate and each of the three corrugations 25a, 25b of the first series and of the three corrugations 26a of the second series which terminate on the notched portion 29a of the inner edge of each notched rectangular metal plate 24a and 24b and on the inner lateral edge of each metal retrofit plate 24c, 24d all around the square window 51, so as to close the terminations of said corrugations.
In other words, the corrugations 25a, 25b and 26a meeting the closure plates 64a, 64b are closed tightly with the end parts 65. The end parts 65 each comprise a baseplate in two parts tightly welded onto the closure plate and a shell tightly welded to the corrugation at the point where it is interrupted.
As can be seen in
By virtue of this arrangement, the corrugated metal sheets 24a, 24b, 24c, 24d and 24e of the secondary sealing membrane 4 form a pattern of 9io dimensions in the first direction X, which simplifies the connection to the adjacent zones of the tank wall, in particular when the latter are formed by insulating panels 2 and rectangular sheets 24 of 3io dimensions in the first direction X.
The corrugations of the metal sheets 24a, 24b, 24c, 24d and 24e protrude toward the outside of the tank in the direction of the bearing structure, the inner face of the secondary insulating panels 2a, 2b, 2c, 2d having right-angled grooves 14 and 15 receiving the corrugations 25 and 26 of the metal sheets 24a, 24b, 24c, 24d and 24e.
As can be seen in
It should be noted in
Referring to
The primary thermally insulating barrier 5 comprises two primary insulating panels 6a, 6b of rectangular parallelepipedal form having a width of 3io in the first direction X and a length of 7io in the second direction Y. A first of said primary insulating panels 6a has its four corners coinciding with the first 19a and the second 19b anchoring members of each series and is anchored to said first and second anchoring members 19a, 19b of each series. A second of said primary insulating panels 6b has its four corners coinciding with the second 19b and the third 19c anchoring members of each series and is anchored to said second and third anchoring members 19b, 19c of each series.
By virtue of this arrangement, the primary thermally insulating barrier 5 can be produced with insulating panels 3io wide, which facilitates the connection with the adjacent zones of the tank wall, Furthermore, a large number of the edges of the primary insulating panels coincide with the anchor plates 17a, 18a, 17b, 18b of the first plurality, which makes it possible to use anchoring members 19a, 19b, 19c securely attached to said mounting plates to anchor the primary insulating panels. Nevertheless, the anchoring of the primary panels 6a, 6b only by the four corners could be insufficient, depending on the mechanical strains that have to be endured.
Each of the two primary insulating panels 6a, 6b has a respective cutout 23a, 23b in its edge turned to the side of the through-element, the cutout 23a of the first primary insulating panel 6a, having a width less than or equal to 1io in the first direction X, and the cutout 23b of the secondary primary insulating panel 6b having a width less than or equal to 2io in the first direction X. Each of the two cutouts 23a, 23b has a length less than or equal to 3io in the second direction and is symmetrical in relation to the first axis of symmetry A.
Since the cutouts 23a, 23b of the primary insulating panels 6a, 6b do not extend beyond the limits of the underlying square window 51, it is possible to manufacture the primary membrane with corrugations whose interruptions at said cutouts are of a length less than the interruptions of the corrugations of the secondary membrane at the square window.
More specifically, in the embodiment represented, the cutouts 23a, 23b take the forms of circular arcs that are concentric with the main body 52 and have one and the same radius corresponding to the outer radius of the circular tray 54 taking into account a mounting play.
The mounting plates 17a of the first plurality also bear a series of anchoring members 19e disposed along the outer longitudinal edge, opposite said cutout 23a, of the first primary insulating panel 6a, for example two anchoring members 19e spaced apart respectively by 2io of the corners of the first primary insulating panel 6a and symmetrical to one another in relation to the first axis of symmetry A. The outer longitudinal edge of the first primary insulating panel 6a is also anchored to the series of anchoring members 19e.
Moreover, in order to also offer five or six anchor points for anchoring to the second primary insulating panel 6b, at least one anchoring member 19f is fixed onto the tray 53 of the support foot 50 on the side of the second primary insulating panel 6b, inside the cutout 23b of the inner longitudinal edge of the second primary insulating panel 6b. Two anchoring members 19f can be seen in
The detailed structure of the tie making it possible to anchor the second primary insulating panel 6b to the anchoring member 19f is shown in
More specifically, the anchoring part 104 here comprises:
A nut 105 bears on the horizontal lug 104a via Belleville spring washers 106.
Referring to
The corrugated metal sheets of the primary sealed membrane 7 around the support foot 50 comprise two primary notched rectangular plates 39a and 39b having a width of 3io in the first direction X and a length of 9io in the second direction Y and overall symmetrical to one another in relation to the second axis of symmetry B. Each of the two primary notched rectangular plates 39a and 39b is overall symmetrical in relation to the first axis of symmetry A. In fact, the edges of the plates 39a and 39b intended to be welded with overlap are slightly dissymmetrical precisely because of the overlaps effected.
Each of the two primary notched rectangular plates 39a and 39b has an inner longitudinal edge 68 having a notch to circumvent the through-element, said notch having a width less than 1.5io in the first direction X and a length less than 3io in the second direction Y such that the notched portion 68a of the inner longitudinal edge 68 interrupts two corrugations 41a of the first series and one corrugation 40a of the second series of each of the two primary notched rectangular plates 39a and 39b.
The notched portion 68a of the inner longitudinal edge of each primary notched rectangular plate 39a and 39b is tightly welded to link parts tightly linked to the through-element around the support foot 50 at the inner face of the primary insulating panels 6a, 6b.
For the most part, the sealed link between the primary notched rectangular plates 39a and 39b and the circular tray 54 can be produced in a way similar to the teaching of WO-A-2011/157915, with two primary closure plates 82 and eight end parts 83.
As can be seen in
The inner face of the first, second and third primary insulating panels 6a, 6b, 6c bears metal anchor plates to anchor the primary notched rectangular plates 6a and 6b, the metal anchor plates comprising:
The top of
As can be seen in
Fifth metal anchor plates 32e are disposed on the third primary insulating panel 6c along a line parallel to the second axis of symmetry B at a distance of 1 io from the third metal anchor plates 32c to anchor the outer longitudinal edge of the narrow rectangular plate 39c.
By virtue of this arrangement, the corrugated metal sheets 39a, 39b, 39c and 24e of the secondary sealing membrane 4 form, around the support foot 50, a network of corrugations 40, 41 that is regular and symmetrical in relation to the two axes of symmetry A and B. Furthermore, the narrow rectangular plate 39c makes it possible to realign, in the first direction X, the outer longitudinal edge with the edges of the primary corrugated metal sheets of an adjacent standard zone, which simplifies the connection of the singular zone to the adjacent zones of the tank wall, which are formed by insulating panels 6 and rectangular sheets 39 of dimensions 3io in the first direction X.
As can be seen in
In another embodiment, the corrugations of the secondary metal sheets 24, 24a, 24b, 24c protrude toward the interior of the tank, contrary to the corrugations of the preceding embodiment, and the primary insulating panels 6, 6a, 6b, 6c each have an outer plate 31 having right-angled grooves receiving the corrugations of the corrugated metal sheets of the secondary sealing membrane 4. In this other embodiment, not represented, the corrugated metal sheets 24, 24a, 24b, 24c of the secondary sealing membrane 4 also comprise two series of right-angled corrugations 25, 26. As in the preceding embodiments, the corrugated metal sheets 24, 24a, 24b, 24c are fixed onto the inner plate 10 of the insulating panels 2 of the secondary thermally insulating barrier 1 via metal mounting plates.
However, in this embodiment, the outer plate 31 of the insulating panels 6 of the primary thermally insulating barrier 5 have two series of grooves at right angles to one another so as to form a network of grooves. The grooves are thus intended to receive the corrugations 25, 26, protruding toward the interior of the tank, formed on the corrugated metal sheets 24 of the secondary sealing membrane 4.
In such an embodiment, the secondary sealing membrane comprises a general structure identical to that represented in
Moreover, it should be noted that while the invention has been described above in relation to a through-element which is a support foot, it is in no way limited to such an embodiment. A similar arrangement can be employed for other through-elements.
Preferably, the through-element is centered on a position corresponding to the intersection between the directing lines of two corrugations at right angles to one another of the secondary metal sheets and has a symmetry of revolution or a symmetry of order N, where N is an even integer number, around an axis at right angles to the bearing wall.
In embodiments not represented, the main body of the through-element is a sealed duct passing through the wall to define a passage between the interior space of the tank and the outside of the tank, or a sump structure passing through the tank wall at the bottom of the tank and intended to accommodate a suction member, for example a pump.
The sump structure can comprise:
In a simplified embodiment, the multilayer structure of the tank wall is limited to the secondary sealed membrane and the secondary insulating barrier, whereas all the primary elements are eliminated.
The tank described above can be used in different types of installation, in particular in an onshore installation or in a floating structure such as a methane tanker or the like.
Referring to
As is known per se, loading/unloading pipelines 73 disposed on the upper deck of the ship can be coupled, by means of appropriate connectors, to a maritime or port terminal to transfer a cargo of LNG from or to the tank 71.
To create the pressure necessary to the transfer of the liquefied gas, pumps embedded in the ship 70 and/or pumps with which the onshore installation 77 is equipped and/or pumps with which the loading and unloading station 75 is equipped are implemented.
Although the invention has been described in relation to several particular embodiments, it is clear that it is no way limited thereto and that it comprises all the technical equivalents of the means described and their combinations provided the latter fall within the scope of the invention.
The use of the verb “comprise” or “include” and its conjugated forms does not preclude the presence of elements or steps other than those stated in a claim. The use of the indefinite article “a” or “an” for an element or a step does not preclude, unless otherwise stipulated, the presence of a plurality of such elements or steps.
In the claims, any reference symbol between parentheses should not be interpreted as a limitation of the claim.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1553496 | Apr 2015 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2016/050891 | 4/15/2016 | WO | 00 |
