WO2013104850A1

WO2013104850A1 - Sealed insulating vessel provided with a primary retaining means

Info

Publication number: WO2013104850A1
Application number: PCT/FR2013/050024
Authority: WO
Inventors: Mohamed Sassi; Sébastien DELANOE; Olivier Perrot; Denis Bernard; Gery Canler; Julien OLLIVIER
Original assignee: Gaztransport Et Technigaz
Priority date: 2012-01-09
Filing date: 2013-01-04
Publication date: 2013-07-18
Also published as: FR2985560A1; KR102026789B1; KR20140108725A; CN104160202A; FR2985560B1

Abstract

The invention relates to a sealed, thermally-insulating vessel, wherein one wall of the vessel comprises two sealing barriers, i.e. a primary (17) and a secondary sealing barrier, and two thermally-insulating barriers, i.e. a primary and a secondary thermally-insulating barrier. The vessel includes retaining means comprising: a pin (5) which is attached to a secondary heat insulator element (2) of the secondary thermally-insulating barrier and which extends through the secondary sealing barrier, and an attachment bracket (11) disposed in a housing (12) of a primary heat insulator element (3) of the primary thermally-insulating barrier. The aforementioned attachment bracket comprises: a base which is attached to an outer surface of the primary heat insulator element (3) that is oriented towards the secondary sealing barrier; and an attachment plate connected to the base and spaced apart from the base by connection means, said connection means and attachment plate being independent from an insulating layer (19) of the primary heat insulator element (3), and the attachment plate being attached to the pin (5).

Description

SEALED AND INSULATED TANK WITH PRIMARY RETENTION MEANS

The invention relates to the field of the manufacture of sealed and thermally insulated tanks. In particular, the present invention relates to a vessel for containing cold or hot liquids, and more particularly to tanks for the storage and / or transport of liquefied gas by sea.

Sealed and thermally insulated tanks can be used to store hot or cold products. For example, liquefied natural gas (LNG) is a liquid that can be stored at atmospheric pressure at about -163 ° C in land-based storage tanks or in tanks embedded in floating structures.

FR2887010 describes such a tank. This comprises two successive sealing barriers, one primary in contact with the product contained in the tank, and the other secondary disposed between the primary barrier and the carrier structure, these two sealing barriers being alternated with two thermally insulating said primary and secondary barriers, each thermally insulating barrier consisting of a plurality of heat insulating elements of generally parallelepipedal shape. Each insulation element has a bottom panel and a plywood top panel. Fasteners hold the primary thermally insulating barrier on the secondary thermally insulating barrier.

According to one embodiment, the invention provides a sealed and thermally insulating tank arranged in a supporting structure for containing a fluid, in which a wall of the tank comprises a primary sealing barrier intended to be in contact with the product contained in said tank, a secondary sealing barrier disposed between said primary sealing barrier and said vessel-carrying structure, a primary heat-insulating barrier consisting of a plurality of primary heat-insulating elements juxtaposed between said two sealing barriers, a secondary heat-insulating barrier consisting of a plurality of secondary heat-insulating elements juxtaposed between said secondary sealing barrier and said supporting structure and retained against the supporting structure of the vessel by secondary holding means, a secondary heat-insulating element comprising an upper panel supporting the b secondary sealed backing, said vessel comprising primary retaining means for retaining said primary heat insulating elements on the secondary watertight barrier, a primary heat insulating element having a bottom panel supported by the secondary watertight barrier and an insulating layer supported by the bottom panel , the primary heat-insulating element further comprising a housing formed in the thickness of the insulating layer and the bottom panel, the primary retaining means comprising:

a stud secured to the top panel of the secondary heat insulating member and extending towards said primary heat-insulating barrier through said secondary watertight barrier, the stud having a flange at said secondary sealing barrier, at the the inside of the tank, and sealingly connected to the secondary sealing barrier,

and a fixing support disposed in the housing of the primary heat-insulating element, the fixing support comprising:

a base having a surface attached to an outer surface of the bottom panel facing the secondary sealing barrier and

a fixing plate parallel to the bottom panel and connected to the base by connecting means, the connecting means holding the fixing plate spaced relative to the base in the direction perpendicular to the secondary sealing barrier,

the connecting means and the fixing plate being independent with respect to the insulating layer of the primary heat insulating element, and the mounting plate of the fixing support having a bore adapted to receive the stud for fixing the fixing support to said stud.

According to embodiments, such a tank may comprise one or more of the following characteristics.

According to one embodiment, the fixing support is a rail and the housing is a groove,

the base consisting of two separate tabs each having an elongate surface fixed along its length on the outer surface of the bottom panel facing the secondary sealing barrier and the connecting means being constituted by two connecting elements each connected to a respective tab and to the mounting plate.

According to one embodiment, the connecting elements each comprise a side plate, the side plate being bonded at an upper edge of the side plate to an edge of the fixing plate and at a lower edge of the side plate to a side edge. the paw.

According to one embodiment, the fixing plate and the connecting elements are elongate in a longitudinal direction parallel to the length of the tabs, the tabs and the plate being connected by the connecting elements over substantially their entire length. According to one embodiment, the rail consists of a profiled body symmetrical with respect to a plane perpendicular to the fixing plate.

According to one embodiment, the groove opens on two opposite sides of the insulating element.

According to one embodiment, the drilling has a drilling direction and the fixing support has a shape of revolution around the drilling direction.

According to one embodiment, the fixing plate has a circular contour centered on the bore, the base has a crown shape parallel to the fixing plate and having an inner contour and the connecting means comprise a substantially conical tube truncated having a first end having a lower section at a second end of the tube, the first end being connected to the circular contour of the fixing plate and the second end being connected to the inner contour of the base.

According to one embodiment, the upper panel supports the secondary sealing barrier on an upper surface of the upper panel, the upper panel of the secondary member further comprising a housing, the housing of the upper panel having a first portion in the form of a hole through the upper surface of the upper panel, the hole having a section and the hole opening on a second portion of the housing of the upper panel, the second portion of the upper panel housing having a larger section than the section of the hole of in such a way as to delimit a bearing surface turned towards the secondary sealing barrier, and the retaining means comprising a guided member carrying the stud and locked in translation in the direction of the secondary sealing barrier by resting on the bearing surface the housing of the upper panel, the stud extending towards said barrier thermally is Primary olante through the first part of housing.

According to one embodiment, the housing of the upper panel has a shape adapted to guide in translation the guided member in a rectilinear direction.

According to one embodiment, the upper panel comprises a second housing spaced from the first housing, the rectilinear direction being defined by the alignment of the two housing.

According to one embodiment, the housing of the upper panel is an oblong groove in the direction of the guidance of the guided part and in a plane parallel to the upper panel. According to one embodiment, the secondary sealing barrier is traversed by the stud in a bore, the stud having a centering recess bearing on the surface of the bore and centering the stud relative to the bore.

According to one embodiment, the housing of the upper panel has a shape adapted to guide the guided member in a plane parallel to the upper panel.

According to one embodiment, the retaining means further comprise an elastic element held in position in the housing of the upper panel and adapted to recall the guided element in translation in a plane parallel to the upper panel.

According to one embodiment, the housing of the upper panel of the secondary element has a cylindrical shape of revolution and the elastic element comprises: a ring bearing on the surface of revolution of the housing of the upper panel and a plurality of legs s' extending radially from the ring towards the inside of the ring and uniformly distributed circumferentially in the ring, the tabs resting on the guided element and the tabs being elastically prestressed so as to exert a force on the guided element.

According to one embodiment, the upper panel of the heat insulating element comprises an insert positioned in a recess of the upper panel and fixed on a surface of the recess of the upper panel opposite to the secondary sealing barrier, and the insert comprises a plate and a cage fixed in the plate, the cage having a recess and a shoulder so as to form the housing of the upper panel.

According to one embodiment, the vessel further comprises:

a second secondary heat-insulating element, the first and second secondary heat-insulating elements being juxtaposed in their lengths, a first part of the primary heat-insulating element being positioned superimposed on the first secondary heat-insulating element and a second part of the primary heat-insulating element being superimposed on the second secondary heat insulator, and

a fixing support and a stud being positioned on each side of a transverse median plane of the primary heat-insulating element, so that the first fixing support and the first stud retain said primary heat-insulating element on the first secondary heat-insulating element and that the second fastening support and the second stud retain said primary heat insulating element on the second secondary heat insulating element.

According to one embodiment, the secondary sealing barrier and the flange are sealingly welded in a connection zone, and in which a protection plate is placed in the recess of the upper panel of the heat-insulating element, the protection being interposed between the secondary insulating barrier and the insert, the protection plate being able to protect the insert from a local temperature rise of the connection zone generated during the sealing connection of the flange to the barrier of secondary sealing, the protection plate being further able to slide relative to the insert.

According to one embodiment, the secondary sealing barrier and the flange are sealingly welded in a connection zone, and in which the cage has a groove on one face of the insert in contact with the secondary sealing barrier. , the groove being positioned to the right of the connecting zone, the groove having a width greater than the width of a weld bead connecting the flange to the secondary sealing barrier.

Such a tank can be part of a land storage facility, for example to store LNG or be installed in a floating structure, coastal or deep water, including a LNG tank, a floating storage and regasification unit (FSRU) , a floating production and remote storage unit (FPSO) and others.

According to one embodiment, a vessel for the transport of a cold liquid product comprises a double hull and a aforementioned tank disposed in the double hull.

According to one embodiment, the invention also provides a method of loading or unloading such a vessel, in which a cold liquid product is conveyed through isolated pipes from or to a floating or land storage facility to or from the vessel vessel.

According to one embodiment, the invention also provides a transfer system for a cold liquid product, the system comprising the abovementioned vessel, insulated pipes arranged to connect the vessel installed in the hull of the vessel to a floating storage facility. or terrestrial and a pump for driving a flow of cold liquid product through the insulated pipelines from or to the floating or land storage facility to or from the vessel vessel. An idea underlying the invention is to provide a vessel wall in which a primary thermally insulating barrier is maintained on a secondary thermally insulating barrier by retaining devices, the retaining devices being connected to the secondary thermally insulating barrier and Attached to a lower surface of the primary thermally insulating barrier, so as to avoid clamping of barrier materials thermally insulating primary and so as to avoid the stress concentrations induced by the differential contraction phenomena.

Some aspects of the invention start from the idea of distributing the holding force back by means of restraining devices exerting a force on extended bearing surfaces of the primary thermally insulating barrier to distribute the stresses.

Some aspects of the invention depart from the idea of making grooves in the thermally insulating barrier to facilitate the flow of fluids through said primary barrier, and to position the retainers in the grooves without obstructing the grooves.

Certain aspects of the invention start from the idea of producing the primary and secondary thermally insulating barriers by means of primary and secondary heat insulating elements, respectively, and of maintaining the primary heat insulating elements on the secondary heat-insulating elements with the aid of studs, the studs being movable relative to the secondary heat insulating elements in a plane parallel to the vessel wall in order to suppress the stress concentrations in the vessel wall between the primary thermally insulating barrier and the secondary thermally insulating barrier by absorbing the deformations of the the supporting structure or the deformations of the heat-insulating elements due to temperature variations.

Some aspects start from the idea of providing two studs per secondary heat insulating element and allowing the sliding of the studs in a single direction consisting of the line formed by the spacing between the two studs.

Some aspects of the invention start from the idea of providing a tank that can be realized in a short time of assembly, and to provide an inexpensive tank, by providing retaining devices able to be pre-assembled and pre-assembled. .

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly in the course of the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes. with reference to the accompanying drawings.

On these drawings:

• Figure 1 is a partial perspective view and torn from a sealed and insulating tank wall having primary retaining devices according to one embodiment of the invention. • Figure 2 is a longitudinal sectional view along the line II-II of the vessel wall and in particular a primary retaining device of Figure 1 comprising a fixing support.

Figure 3 is a detail view of the retainer of Figure 2 having an insert and a stud.

• Figure 4 is a sectional view of the insert along line IV-IV.

FIG. 5 is a perspective view from below of a primary insulating box of the tank wall of FIG. 1

• Figure 6 is a partial sectional view along line VI-VI of the primary insulating box.

FIG. 7 is a perspective view of an insert according to another embodiment comprising an elastic ring.

FIG. 8 is a perspective view of the elastic ring of the insert of FIG.

FIG. 9 is a sectional view along the line ΙΧ-IΧ of the insert of FIG. 7.

FIG. 10 is a top view of the insert of FIG. 7.

• Figure 11 is a partial sectional view of a primary insulating box comprising a mounting bracket according to a variant.

FIG. 12 is a perspective view of the fixing support of FIG. 11. FIG. 13 is a cutaway schematic representation of a tank of a LNG carrier and a loading / unloading terminal of this tank.

• Figure 14 is a partial sectional view of Pinsert of Figure 9 in a variant having a groove in line with the sealed sealing zone of the barrier.

• Figure 15 is a partial sectional view of Pinsert of Figure 9 according to a variant comprising a protective plate.

Referring to Figure 1, there will be described a vessel wall mounted on the support structure 1 consisting of the double hull of a ship.

By convention, we will call "above" a position located closer to the inside of the tank and "below" a position located closer to the supporting structure 1, whatever the orientation of the tank wall by compared to the Earth's gravity field.

Such a tank wall comprises a secondary heat-insulating barrier carried by the supporting structure 1, this secondary heat-insulating barrier carries a secondary sealing barrier 18, itself surmounted by a heat barrier. primary insulation. The primary thermally insulating barrier carries a primary sealing barrier 17.

The secondary thermally insulating barrier and the primary thermally insulating barrier essentially consist of essentially primary 3 and secondary 2 respectively substantially parallelepiped heat insulating elements. The secondary heat-insulating elements 2 are arranged side by side in the form of parallel rows so as to substantially cover the internal surface of the supporting structure 1.

Each heat-insulating element 2 of the secondary thermal-insulating barrier comprises a lower panel 15 and an upper panel 4 between which is a layer of insulating foam 20. The lower panels 15 of the secondary thermally insulating barrier rest on the supporting structure 1 by the intermediate mastic cords 16 forming parallel lines. The heat-insulating elements 3 of the primary thermally insulating barrier have a structure similar to the heat-insulating elements 2 of the secondary thermally insulating barrier and thus consist of a lower panel 14 surmounted by a layer of insulating foam 19 itself carrying an upper panel. 6. The primary heat-insulating elements 3 have for example a length of 2000mm, a width of 1000mm and a thickness of 100mm.

A sheet of kraft paper, not shown, is positioned on the supporting structure 1 below the mastic cords 16 in order to prevent the resin of the mastic cords 16 from sticking to the supporting structure 1. These cords of mastic 16 allow thus, during the dynamic deformations of the carrier structure 1, to reduce the forces suffered by the secondary heat insulating elements due to said deformation. The mastic cords 16 are intended to make up the differences between the theoretical surface provided for the tank wall and the imperfect surface of the supporting structure 1 resulting from manufacturing tolerances.

The heat-insulating elements 2 of the secondary thermally insulating barrier are anchored against the supporting structure 1 by secondary retaining means (not shown). Such secondary retaining means can be made in different ways, for example according to the embodiments described in the document FR2887010 or in the French patent application filed under number 1162214.

The upper panel 4 of the secondary heat insulating element 2 comprises two grooves 7 of inverted T-shaped section to receive welding wings in the shape of a square (not shown). The secondary sealing barrier 18 consists of strakes with raised edges welded to the welding wings in a manner well known to those skilled in the art.

To maintain the primary heat-insulating elements 3 against the secondary heat-insulating barrier 2, studs 5 are held in the upper panels 4 of the secondary heat-insulating elements 2, pass through the strakes and are fixed to the primary heat-insulating elements 3.

A primary heat insulating element 3 comprises two lateral grooves 8 formed through the lower panel 14 and in the insulating foam layer 19 to accommodate the raised edges and the upper part of the welding flanges.

In the same way as the secondary heat-insulating element 2, the upper panel 6 of the primary heat-insulating element 3 has two T-shaped grooves 9 for receiving unrepresented welding wings. Strakes with raised edges are welded to the wings to form the primary sealing barrier 17.

Each secondary heat insulating element 2 comprises two studs 5 each located at a quarter of the length of the secondary heat insulating element 2, each from the middle of one of the short sides of the heat insulating element. Each primary heat insulating element 3 is placed astride two secondary heat insulating elements 2, the primary heat insulating element 3 being fixed to the respective studs of the contiguous parts of the two secondary heat insulating elements 2 on which it is positioned.

This arrangement avoids a vertical offset between the secondary heat insulating elements 2 in case of ballast or sloshing fluid in the tank. Thus, damage to strakes and raised edges is avoided.

Figures 2 and 3 are sectional views of the wall of Figure 1. In these sectional views, we see more precisely the retaining means maintaining the primary heat insulating elements 3 on the secondary heat insulating elements 2. The stud 5 is partially represented in the form of an outer silhouette.

As can be seen in FIG. 2, each bolt 5 is screwed into an insert 10 integrated in the upper panel 4. A primary heat-insulating element 3 is fixed on the stud 5 via an anchor rail 11 fixed on the lower surface of the heat insulating element 3.

Looking at FIG. 3, it can be seen that in order to receive the insert 10, the upper panel 4 has a bore 28 passing through the panel having a recess 21 on a lower part of the upper panel 4. The insert 10 has a circular plate 22 surmounted by a circular projection 42 centered on the plate 22. The circular plate 22 rests on the recess 21 and the projection 42 passes through the bore 28 to flush at the surface Upper panel top 4.

The insert 10 further comprises a cylindrical cavity 24 passing through the thickness of the projection 42, whose internal bearing is threaded. A cylindrical cage 23 is screwed onto the tapping so as to enclose an oblong nut 25 previously placed in the cylindrical cavity 24. For this, a housing in the form of a groove 33 formed in the cage 23 receives the oblong nut 25.

The cage 23 and the protrusion 42 are flush with the upper surface of the upper panel 4 to carry the secondary sealing barrier 18 continuously over substantially the entire upper surface of the secondary heat-insulating element 2.

The secondary sealing barrier 18 has a circular hole 47 centered on the cage 33 through which the stud 5 extends. In fact, the stud 5 is screwed to the oblong nut 25 through the circular hole 47, through a bore 31 which passes through the cage 23 at the bottom of the groove 33 and through the washer 34. A threaded portion 27 of the stud 5 is screwed onto the nut 25. In this way, the elongated nut 25 is supported on a washer polytetrafluoroethylene (PTFE) positioned on the bottom of the groove 33 of the cage 23. This threaded portion 27 is surmounted by a flange 29 which is supported on the sealed barrier 18. The flange 29 further comprises a centering recess 31 bearing on the periphery of the circular hole 47 to center the stud 5 with respect to the circular hole 47. The flange 29 is surmounted by a second threaded portion 48 on which is clamped the anchoring rail 11.

Figure 4 is a sectional view along the line IV-IV of the insert 10. The groove 33 has an oblong shape. The oblong nut 25 has a width equal to the width of the groove 33 to block its rotation in the groove 33 and thus allow the bolt 5 to be screwed into a threaded bore 27 of the elongated nut. The length of the elongated nut 25 is, in turn, less than the length of the groove 33 to allow the sliding of the elongated nut 25 in the direction of the groove 33. This sliding is also allowed by the width of the drilling 31 which is larger than the threaded portion 27 of the stud 5. The length between each side of the elongated nut 25 and the end of the oblong groove 33 is 3mm to allow sliding of the oblong nut 25 3mm of each side of the oblong nut 25. In this way, the oblong nut 25 and the cage 23 form a slide. The oblong groove 33 is oriented in a direction parallel to the line formed by the position of the two inserts 10 and also corresponds to the longitudinal direction of the ship.

The sliding being performed along the longitudinal axis of the ship, all stress concentrations are avoided in the secondary waterproof membrane 18 during the thermal contraction of the heat insulating elements 2 and 3 or during the bending of the beam of the ship to the swell.

For example, during the cold setting of the tank, the thermal shrinkage of a secondary panel 2 can induce an approximation of the inserts 10 by about 1 mm, the relative sliding of the studs 5 makes it possible to make up the variation of distance between the two inserts 10. In the same way, these retainers make it possible to make up for the length variations produced when the secondary membrane 18 is under stress. For example, when the secondary waterproof membrane 18 is subjected to OOMPa constraints, this elastic elongation can be equal to 0.71 mm / m.

Two holes 35 made in the cage 23 can cooperate with an associated tool to facilitate mounting by screwing the cage 23 in the cavity 24. In addition, the plate 22 has two holes 36 through which screws not shown tighten the plate 22 against the top panel 4.

Two inserts 10 are pre-mounted in a secondary heat-insulating element 2 during its manufacture. The two inserts 10 are previously fixed in two holes 28 and two respective recesses 21 of the upper panel 4 and then the upper panel is bonded to the insulating foam layer 20.

The pre-assembly of the insert 10 in the heat-insulating elements 2 makes it possible to facilitate the production of the wall inside the tank.

These inserts are also used during assembly to drill the primary waterproof membrane 18. For this purpose, a punch is screwed into the insert 10 of the secondary heat-insulating element 2 and the secondary waterproof membrane 18 is positioned on the punch. The punch is centered relative to the insert 10 through the inner bearing bore 31. A counterpoise then cooperates with the pomçon to drill the secondary diaphragm 18. Thus, the hole 47 of the secondary waterproof membrane 18 is centered with the cylindrical cage 23. Thanks to this centering, the stud 5 is centered, during assembly, with respect to the cylindrical cage 23 and more particularly with respect to the groove 33 thanks to its recess 30. In this way, the oblong nut 25 is also centered with respect to the groove 33. FIGS. 5 and 6 make it possible to observe in greater detail the structure of the anchoring rails 11 fastened under each primary heat-insulating element 3. Each of these rails 11 is in the form of a U-section section having a first plate 41 elongate between two side plates 40 extending in the same direction perpendicular to the first plate 41. Each side plate 40 has a flange 39 at its edge opposite the first plate 41. This flange 39 extends parallel to the first plate 41. first plate 41. Each anchor rail has for example a length of 400mm and a height of 36mm.

The lower panel 14 of the primary heat-insulating element 3 is separated into 4 parts by the two lateral grooves 8 intended to receive the raised edges of the secondary leak-proof barrier 18 and a central groove 12 in which two anchoring rails 11 are positioned.

These grooves 8 and 12 extend over the entire length of the primary heat-insulating element 3 and extend, in their depth, through the lower panel 14 and through a portion of the thickness of the insulating layer 19 of the primary heat-insulating element 3.

The two parts of the lower panel 14 adjacent the central groove 12 have a recess 38 on their lower surface 50. The wings 39 of the anchor rail 11 are fixed on the surface of the recess 38 directed towards the secondary sealed barrier. For this, wood screws are screwed into the lower panel 14 through holes 37 distributed along the wings 39. The side plates 40 and the upper plate 41 are themselves independent of the insulating mass and the upper panels 6 and lower 14.

These rails 11 allow attachment of the primary heat-insulating elements 3 by the lower surface 50 of the lower panels 14. In this way, the problems due to the differential thermal contraction between the studs 5 and the heat-insulating elements 3 are avoided. Moreover, the studs 5 exert no compressive stress on the insulating foam layer 19 and the lower panels 14 and upper 6 of the primary heat-insulating elements 3.

A hole in the center of the upper plate 41 is traversed by the threaded upper portion 48 of the stud 5. As can be seen in Figure 2, the stud 5 is fixed to the rail 11 by means of a nut 25 screwed onto the stud 5 in a chimney 13 extending to the right of the bore 46. These chimneys 13 are then filled with a foam lining 49 which extends to the upper surface of the upper panel 6.

Returning to FIG. 2, it can be seen that the grooves of the heat-insulating elements are aligned, to generate passages in the primary insulating barrier through which fluids can flow. By virtue of this, a nitrogen sweep of the primary heat-insulating barrier is facilitated, which allows the inerting of the space between the primary and secondary watertight barriers 18. With reference to FIGS. 7 to 10, a variant of the insert 10 will now be described.

FIG. 7 is a perspective view of an insert 100 having a function similar to the insert 10. Like the insert 10, the insert 100 comprises a plate 122 comprising two bores 36 intended to receive screws for tightening the plate against the recess 21 of the upper panel 4. The insert 100 comprises an elastic ring 43 shown in perspective in FIG.

In FIG. 9, it can be seen that similarly to the insert 10, the plate 122 has a projection 142 having a threaded cylindrical cavity 123 and which is flush with the upper surface of the upper panel 4. A cylindrical cage 123 is screwed to the cylindrical cavity 124 and is flush with the upper surface of the upper panel 4. The cage 123 comprises a recess 133 and a hole 131 centered with the outer bearing surface of the cylindrical cage 124. The elastic ring 43 has an external diameter equal to the diameter of the recess 133 and is positioned against the bottom 132 of the recess 133. This ring maintains a hexagonal nut 125 at the center of the recess 133. When mounting the wall of the tank, the stud 5 is screwed through the hole 131 to the thread 126 of the nut. 125. The nut 125 thus rests on the bottom surface 125 of the recess 133.

The hole 131 has a hexagonal shape, as can be seen in FIGS. 7 and 10, to facilitate the screwing of the cage 123 by means of a hexagonal tool such as a hexagon socket wrench. However, the dimensions of the hole 131 are smaller than the dimensions of the nut to allow the support of the nut 125 on the bottom surface 132 of the recess 133. Furthermore, the cage 123 has a chamfer 51 on its lower outer contour and the projection 142 has a chamfer 52 on the contour of the cylindrical cavity 124 to facilitate the positioning of the cage 123 prior to screwing thereof.

Figures 8 and 10 illustrate more precisely the shape of the elastic ring 43. This comprises a ring 45 whose outer diameter corresponds to the internal diameter of the recess 133. Six lugs 44 extend from the inner bearing of the ring 45 inwardly of the ring 43. These tabs 44 are uniformly distributed circumferentially on the ring 44. The tabs 44 are curved so as to form a V. Each of the legs 44 is supported at its end, and in flexion, on a facet 48 of the nut 125 and thus works in compression due to its elastic deformation.

The insert 100 allows the sliding of the rigid assembly formed by the stud 5, the nut 125, the primary waterproof barrier 18 and the primary heat-insulating element 3 with respect to the insert 100 and the secondary heat-insulating element 2. However, this sliding is limited by the elastic stiffness of the legs 44 which work in compression. This sliding is imposed in a plane formed by the bottom surface 132 of the recess 133. Thus, like the insert 10, this variant of the insert 100 makes it possible to avoid any concentration of stress.

Furthermore, the compression work of the tabs 44 of the spring washer 43 allows the elastic return of the nut 125. The ring 43 thus allows to center the nut 125 during assembly. The centering being achieved through the elastic ring 43, a recess 30 on the stud 5 is no longer necessary. The resilient ring 43 also makes it possible to immobilize the nut 125 in rotation when the stud 5 is screwed onto the nut 125 and the nut 125 is braked when it is screwed on.

As seen above, the stud 5 retains a peripheral freedom in a plane parallel to the wall of the tank or along an axis located in this plane in order to eliminate the stress concentrations in the tank wall between the heat barrier. primary insulation and the secondary thermally insulating barrier. By passing through the secondary sealing barrier 18, the stud 5 breaks this seal in the crossing zone. Referring to Figures 14 and 15, the seal is restored by a weld bead bonding the stud 5 to the secondary sealing barrier 18. For this, the flange 29 comprises a connecting plate 200 in contact with the barrier of secondary sealing 18. The seal between the stud 5 and the secondary sealing barrier 18 is formed in the region of this connecting plate 200 by a sealed weld bead conforming to the shape of the flange 29. In this example the bead realized welding is circular.

When making a tight connection, the heat of the weld raises the temperature of the connecting plate 200 and the secondary sealing barrier 18 to obtain a point melting. The temperature reached during the welding is dependent on the materials used for each element. The secondary sealing barrier 18 is in contact with the cage 23, 123, in the region of the stud 5. By thermal conduction, the secondary sealing barrier 18 transmits heat to the cage, which under the effect of the high temperature could be welded with the secondary sealing barrier 18 and the flange 29 of the stud 5. A connection between these three elements would remove the mobility of the stud 5 relative to the secondary heat insulating elements in the plane parallel to the vessel wall. according to embodiments, thermal protection elements are provided to prevent the creation of such a connection between the cage 23, 123 and the secondary sealing barrier 18.

With reference to FIG. 14, the cage 223 comprises a cavity 201 of circular shape disposed in line with the welding zone of the flange plate 29 with the secondary sealing barrier 18. This cavity 201 is dimensioned to allow the realization of the welding while maintaining the temperature of the cage below its melting point. For example, the groove can have a depth of 0.2mm, for an inside diameter of 32mm and an outside diameter of 40mm.

With reference to FIG. 15, the cage 323 is isolated from the insulating barrier by a disk 202. This disk 202 serves as a protective screen for the cage 323 during the welding operation of the collar 29 on the barrier. secondary sealing 18. The disc 202 ensures that the secondary sealing barrier 18 remains movable relative to the cage 323, after the welding operation. The disk 202 may be metallic or not. In the case where the disc 202 is metallic, it can very well be welded with the secondary sealing barrier 18 but remains free with respect to the cage 323. The disc 202 may be in any material providing thermal protection between the cage 323 and the secondary sealing barrier 18. Once the seal is assembled between the flange 29 and the secondary sealing barrier 18 made, the disc 202 serves as a localized support zone for the secondary sealing barrier 18. It guarantees the continuity of level under this secondary sealing barrier 18 in the fixing zones of the studs 5.

Referring to Figures 11 and 12, will now be described another embodiment of the primary heat insulating element 3 in which the anchor rail 11 is replaced by another mounting bracket.

In this embodiment, the stud 5 is not attached to an anchoring rail but to an anchoring bell 111. The anchoring bell 111 has a shape of revolution and comprises a circular upper plate 141 connected to the upper end of a frustoconical portion 140. A base 139 extends around the lower end of the frustoconical portion 140 and has holes 137 distributed circumferentially uniformly on the base 139 to allow attachment with wood screws of the bell 111 on the lower panel 114 of the primary heat-insulating element 3. The base 139 has for example an outer diameter of 150mm. The anchoring bell 111 has, for example, a height of 32.5 mm.

The bell 111 is placed in a cavity 112 having a frustoconical shape of revolution extending through the lower panel 114 and in part of the thickness of the insulating layer 119. A clearance between the bell and the internal surface of the cavity 112 makes it possible to avoid any interaction between the anchoring bell 111 and the insulating foam layer 119 and the lower panel 1 14 in the thickness of the heat insulating element. In a similar manner to the previous embodiment, the base 139 is fixed on a recess surface 138 which follows the periphery of the cavity 112 on the bottom surface of lower panel 1 14. A chimney 13 allows the screwing of a nut from the top of the primary heat insulating element 3.

Although in the embodiments above, the fasteners of the rail 11 and the bell 11 are made using wood screws, any other fastening means can be used. For example, the fixing of the bell or the rail can be obtained by gluing, riveting.

The tanks described above can be used in various types of installations such as land installations or in a floating structure such as a LNG tank or other.

Referring to Figure 13, a broken view of a LNG tank 70 shows a sealed and insulated tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary sealed barrier intended to be in contact with the LNG contained in the tank, a secondary sealed barrier arranged between the primary waterproof barrier and the double hull of the ship, and two insulating barriers arranged respectively between the barrier primary waterproof and secondary watertight barrier, and between the secondary watertight barrier and the double hull 72.

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

Fig. 13 shows an example of a marine terminal including a loading and unloading station 75, an underwater pipe 76 and an onshore installation 77. The loading station and. unloading system 75 is an offshore fixed installation comprising a movable arm 74 and a tower 78 which supports the mobile arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79 that can connect to the loading / unloading pipes 73. The movable arm 74 orientable fits all gauges of LNG carriers. A connection pipe (not shown) extends inside the tower 78. The loading and unloading station 75 enables the loading and unloading of the LNG tank 70 from or to the shore facility 77. storage tanks of liquefied gas 80 and connecting lines 81 connected by the underwater line 76 to the loading or unloading station 75. The underwater line 76 allows the transfer of the liquefied gas between the loading or unloading station 75 and the installation on land 77 over a large distance, for example 5 km, which keeps the LNG tanker 70 at a great distance from the coast during the loading and unloading operations.

In order to generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and / or pumps equipping the shore installation 77 and / or pumps equipping the loading and unloading station 75 are used.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is not limited thereto and that it comprises all the technical equivalents of the means described and their combinations if they are within the scope of the invention.

The use of the verb "to include", "to understand" or "to include" and its conjugated forms does not exclude the presence of other elements or steps other than those set out in a claim. The use of the indefinite article "a" or "an" for an element or a step does not exclude, unless otherwise stated, the presence of a plurality of such elements or steps.

In the claims, any reference sign in parentheses can not be interpreted as a limitation of the claim.

Claims

1. Sealed and thermally insulating vessel arranged in a carrier structure (1) for containing a fluid,

wherein a wall of the vessel has a primary sealing barrier for contacting the product contained in said vessel, a secondary sealing barrier (18) disposed between said primary sealing barrier and said bearing structure of the tank, a primary heat-insulating barrier consisting of a plurality of primary heat insulating elements (3) juxtaposed between said two sealing barriers, a secondary heat-insulating barrier consisting of a plurality of secondary heat-insulating elements (2) juxtaposed between said secondary sealing barrier and said supporting structure and retained against the bearing structure of the vessel by secondary holding means, a secondary heat-insulating element (2) comprising an upper panel (4) supporting the secondary watertight barrier,

said vessel comprising primary retaining means (10, 5, 11) for retaining said primary heat insulating elements (3) on the secondary watertight barrier, a primary heat insulating element (3) having a bottom panel (14, 114) supported by the a secondary sealed barrier and an insulating layer supported by the bottom panel (14, 114), the primary heat insulating element further comprising a housing formed in the thickness of the insulating layer and the bottom panel,

the primary retaining means comprising:

a stud (5) attached to the upper panel of the secondary heat insulating member and extending towards said primary heat-insulating barrier through said secondary watertight barrier, the stud having a flange (29) at said barrier; secondary sealing, on the inside of the tank, and sealingly connected to the secondary sealing barrier,

and a fixing support (11) disposed in the housing of the primary heat insulating element, the fixing support comprising:

a base (39, 139) having a surface attached to an outer surface (38) of the bottom panel (14, 114) facing the secondary sealing barrier and

a fixing plate (41, 141) parallel to the bottom panel and connected to the base (39,

139) by connecting means (40, 140), the connecting means holding the fastening plate spaced relative to the base in the direction perpendicular to the secondary sealing barrier,

the connecting means and the fixing plate being independent with respect to the layer insulation (19) of the primary heat insulating element, and the securing bracket mounting plate having a bore (46) adapted to receive the stud (5) for securing the mounting bracket to said stud (5).

The vessel according to claim 1, wherein the attachment support is a rail (11) and the housing is a groove (12),

the base consisting of two separate wings each having an elongated surface fixed along its length on the outer surface of the bottom panel facing the secondary sealing barrier and the connecting means being constituted by two connecting elements (40) linked each to a respective wing (39) and to the attachment plate.

A vessel according to claim 2, wherein the connecting members each comprise a side plate (40), the side plate being bonded at an upper edge of the side plate to an edge of the fixing plate (41) and in one lower edge of the side plate at one edge of the wing (39).

4. Sealing tank according to claim 2 or 3, wherein the fixing plate and the connecting elements (40) are elongate in a longitudinal direction parallel to the length of the wings, the wings and the plate being connected by the connecting elements. over substantially their entire length.

5. Sealing tank according to claim 4, wherein the rail (11) consists of a profile body symmetrical with respect to a plane perpendicular to the fixing plate.

6. Sealed tank according to one of claims 2 to 5, wherein the groove (12) opens on two opposite sides of the primary heat insulating element (3).

Watertight vessel according to claim 1, wherein the bore (46) has a drilling direction and the fixing support has a shape of revolution around the drilling direction.

Watertight vessel according to claim 7, wherein

the fixing plate (141) has a circular contour centered on the bore (46), the base (139) has a crown shape parallel to the fixing plate and having an inner contour and

the connecting means comprise a tube (140) of substantially truncated conical shape having a first end having a lower section at a second end of the tube, the first end being connected to the circular contour of the fixing plate and the second end being connected to the inside contour of the base.

Watertight vessel according to one of Claims 1 to 8, in which: the upper panel of the secondary heat-insulating element supports the secondary sealing barrier on an upper surface of the upper panel of the secondary heat-insulating element,

the upper panel of the secondary member further having a housing (33, 133), the upper panel housing having a first portion in the form of a hole traversing the upper surface of the top panel, the hole having a section and the hole opening on a second portion of the upper panel housing, the second portion of the upper panel housing having a larger section than the section of the hole so as to define a bearing surface (32, 132) facing the barrier of secondary sealing,

the retaining means comprising a guided member (25, 125) carrying the bolt (5) and locked in translation in the direction of the secondary watertight barrier by resting on the bearing surface (32, 132) of the upper panel housing , the stud (5) extending towards said primary thermally insulating barrier through the first portion of the housing.

10. Sealed vessel according to claim 9, wherein the housing of the upper panel has a shape adapted to guide in translation the guided member (25) in a rectilinear direction in a plane parallel to the upper panel.

11. Sealed vessel according to claim 10, wherein the upper panel has a second housing spaced from the first housing (32), the rectilinear direction being defined by the alignment of the two housing.

Watertight vessel according to claim 10 or 11, wherein the housing (32) of the upper panel is an oblong groove in the direction of the guidance of the guided part and in a plane parallel to the upper panel.

13. Sealed tank according to one of claims 9 to 12, wherein the secondary sealing barrier is traversed by the stud (5) in a bore (47), the stud having a centering recess (30) resting on the surface of the bore and centering the stud relative to the bore.

14. Sealed tank according to claim 9, wherein the housing of the upper panel has a shape adapted to guide the guided member (19) in a plane parallel to the upper panel.

15. Sealed vessel according to claim 14, wherein the retaining means further comprise a resilient element (43) held in position in the housing. of the upper panel and adapted to recall the member guided in translation in a plane parallel to the upper panel to a position centered in the housing.

Watertight vessel according to claim 15, wherein the housing (133) of the upper panel of the secondary element has a cylindrical shape of revolution and the elastic element (43) comprises:

a ring bearing on the surface of revolution of the housing of the upper panel and a plurality of tabs (131) extending radially from the ring towards the inside of the ring and uniformly distributed circumferentially in the ring, the tabs (44). ) based on the guided element and the tabs being elastically biased so as to exert a force on the guided element.

17. Sealed tank according to one of claims 9 to 16, wherein the upper panel of the heat insulating element comprises an insert (10, 100) positioned in a recess (21) of the upper panel and fixed on a surface of the chamber of the upper panel opposite the secondary sealing barrier, and wherein the insert comprises a plate (22, 122) and a cage (23, 123) fixed in the plate, the cage having a recess and a shoulder so as to form the housing of the upper panel.

18. Sealed vessel according to one of claims 9 to 17 wherein the vessel further comprises:

a second secondary heat-insulating element (2), the first and second secondary heat-insulating elements being juxtaposed in their lengths, a first part of the primary heat-insulating element being positioned superimposed on the first secondary heat-insulating element and a second part of the primary heat-insulating element being superimposed on the second secondary heat-insulating element, and

a fastening support (11, 111) and a stud (5) being positioned on each side of a transverse median plane of the primary heat insulating element, so that the first fastening support and the first stud retain said primary heat insulating element on the first secondary heat-insulating element and the second fixing support and the second stud hold said primary heat-insulating element on the second secondary heat-insulating element.

Watertight vessel according to one of Claims 17 to 18, in which the secondary sealing barrier and the flange (29) are sealingly welded in a connection zone (200), and in which a protection plate ( 202) is placed in the recess of the upper panel of the heat insulating element, the protection plate (202) being interposed between the secondary insulating barrier (18) and the insert, the protection plate being able to protect the insert of the insulating element. a local temperature rise of the generated splice area when sealingly connecting the collar to the secondary sealing barrier, the protection plate being further adapted to slide relative to the insert.

Watertight vessel according to one of Claims 17 to 18, in which the secondary sealing barrier (18) and the flange (29) are sealingly welded in a connection zone (200) and in which the cage comprises a groove (201) on one face of the insert in contact with the secondary sealing barrier, the groove being positioned in line with the connection zone, the groove having a width greater than the width of a weld seam connecting the flange to the secondary sealing barrier.

21. Ship (70) for the transport of a cold liquid product, the vessel comprising a double hull (72) and a tank (71) according to one of claims 1 to 20 disposed in the double hull.

22. Use of a ship (70) according to claim 21 for the loading or unloading of a cold liquid product, in which a cold liquid product is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or land storage facility (77) to or from the vessel vessel (71).

23. Transfer system for a cold liquid product, the system comprising a ship (70) according to claim 21, insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull. the vessel to a floating or land storage facility (77) and a pump for driving a flow of cold liquid product through the insulated pipelines from or to the floating or land storage facility to or from the vessel vessel.