EP3707424A1

EP3707424A1 - Sealed and thermally insulating tank

Info

Publication number: EP3707424A1
Application number: EP18804368.1A
Authority: EP
Inventors: Antoine PHILIPPE; Marc BOYEAU; Sébastien DELANOE; Mickaël HERRY
Original assignee: Gaztransport et Technigaz SA
Current assignee: Gaztransport et Technigaz SA
Priority date: 2017-11-06
Filing date: 2018-10-26
Publication date: 2020-09-16
Anticipated expiration: 2038-10-26
Also published as: SG11202004102RA; WO2019086790A1; FR3073272B1; CN111527340B; KR102501626B1; RU2761702C1; KR20200088360A; JP2021501858A; EP3707424B1; CN111527340A; FR3073272A1; JP7154292B2; ES2958660T3

Abstract

The invention relates to a sealed and thermally insulating tank in which the insulating barrier comprises a row of angle structures (30), said angle structure comprising a dihedral insulating block (31) and a metal angle section (32), in which two successive angle structures in said row are arranged so as to have a spacing (38), said spacing being at least partially covered by the projecting portion (53) of the metal angle section, in which the support surface bears an anchoring member (45) arranged between the dihedral insulating blocks of the two angle structures, and a cutout (54) formed in the projecting portion of the metal angle section provides an access to said anchoring member (45).

Description

Watertight and thermally insulating tank

Technical area

The invention relates to the field of sealed and thermally insulating tanks, with membranes, for storing and / or transporting fluid, such as a cryogenic fluid.

Watertight and thermally insulating membrane tanks are used in particular for the storage of liquefied natural gas (LNG), which is stored at atmospheric pressure at about -162 ° C. These tanks can be installed on the ground or on a floating structure. In the case of a floating structure, the tank may be intended for the transport of liquefied natural gas or to receive liquefied natural gas used as fuel for the propulsion of the floating structure.

Technological background

Various techniques are known for the construction of a sealed and thermally insulating diaphragm tank integrated in a bearing structure having a substantially polyhedral inner surface and comprising successively, in a thickness direction, a secondary insulation barrier, a barrier of secondary sealing, a primary insulation barrier and a primary sealing barrier.

WO-A-2014167214 or WO-A-2017006044 discloses a vessel wall in which the secondary insulating barrier consists essentially of secondary insulating blocks juxtaposed on the polyhedron inner surface of the supporting structure, the barrier secondary sealing consists of a corrugated metal membrane disposed on an inner surface of the secondary insulating blocks, the primary insulation barrier consists essentially of primary insulation blocks juxtaposed on the secondary metal membrane and anchored to the secondary insulation barrier by anchoring members carried by the secondary insulating blocks, and the primary sealing barrier consists of a corrugated metal membrane disposed on an inner surface of the primary insulating blocks. Along the edges of the supporting structure, the primary and secondary insulating blocks consist of prefabricated corner structures.

summary Certain aspects of the invention will now be explained with reference to FIG. 1. FIG. 1 partially illustrates an isolation barrier consisting essentially of insulating blocks juxtaposed on a polyhedral support surface 1 having two plane regions 2 and 3 forming an angle between them and joining at an edge 4. The insulating blocks comprise a corner structure 5 disposed along the edge which has two respectively parallel to each of the two planar regions 2 and 3 and flat insulating panels 6 arranged on the flat regions of the support surface on either side of the corner structure 5.

As can be seen in FIG. 1, if the planar insulating panels 6 have been mounted first, there may be a space problem preventing the corner structure 5 from being placed along the edge, as indicated by the arrow 7 It follows that it may be preferable to build the insulation barrier by finishing with a flat region. However, once the corner structure 5 has been placed along the edge, an entire area of the support surface near the edge 4 is no longer accessible.

In addition, it is preferable to make an insulation barrier with insulating blocks as standardized as possible to reduce manufacturing costs. However, the construction of a large supporting structure such as the hull of a ship is subject to high dimensional tolerances, for example several centimeters, which prevent fully planning the dimensions of a tank before its construction. It follows that it may be necessary to build at least some of the insulating blocks tailored to the actual dimensions of the carrier structure.

An idea underlying the invention is to provide a sealed and thermally insulating tank with a multilayer structure that facilitates taking into account at least some of the aforementioned constraints. Another idea underlying the invention is to provide a tight and insulating multilayer structure that is easy to perform on large surfaces.

For this, the invention provides a sealed and thermally insulating vessel for storing a fluid, the sealed and thermally insulating vessel having an insulation barrier and a sealing barrier disposed on an inner surface of the insulation barrier. , the isolation barrier being disposed on a support surface, for example substantially polyhedral, carrying organs anchoring and retaining on the support surface by said anchoring members, the support surface having at least two planar regions forming an angle therebetween and joining at an edge region,

wherein the insulation barrier comprises a row of corner structures disposed along said edge region of the support surface and planar insulating panels disposed on the planar regions of the support surface on either side the row of corner structures,

wherein at least one or each said corner structure comprises:

a dihedral insulating block having two sides respectively parallel to the plane regions and forming an angle between them, said or each pan having a plane outer surface bearing against the corresponding plane region of the support surface and a plane inner surface parallel to said region; plane and spaced apart from said planar outer surface in a thickness direction, and

- a metal angle fixed to the flat inner surfaces of the dihedral insulating block to form said sealing barrier to the right of the edge region of the support surface, the metal angle having a protruding portion which projects relative to the insulating block dihedral in the direction of the edge region, wherein two successive corner structures in said row are arranged to have a spacing in the direction of the edge area between the dihedral insulating blocks, said spacing being at least partially covered by the protruding portion of the metal angle of at least one of the two successive angle structures,

wherein the support surface carries a said anchoring member disposed between the dihedral insulating blocks of the two corner structures.

The anchoring member can thus be used to retain an element of the insulation barrier on the support surface, for example a plane insulating panel adjacent to the row of corner structures or a dihedral insulating block of the row of corner structures.

According to embodiments, such a tank may comprise one or more of the following characteristics. According to one embodiment, said at least one of the two successive angle structures has a cutout formed in the protruding portion of the metal angle to the right of said anchoring member disposed between the dihedral insulating blocks, to provide access to said body. anchor.

Thanks to such a cut, the anchoring member disposed between the two dihedral insulating blocks remains accessible after the establishment of the row of corner structures, despite the presence of a projecting portion of one or both metal angles which at least partially overlaps the spacing between the two dihedral insulating blocks. This access makes it possible to easily act on the anchoring member from the inner surface of the angle, for example by means of a screwing tool

The projecting portion of the metal angles makes it possible to limit the spacing between the metal angles of the successive corner structures, which facilitates sealing of the sealing barrier by means of closure pieces and improves the carrying of these closure pieces. and the sealing membrane in general. A metal angle may have the projecting portion at one end or two projecting portions at its two opposite ends in the direction of the edge region. The cutout formed to the right of the anchoring member may extend in the projecting portion of a single metal angle or in the two projecting portions facing each other of the two successive metal angles.

According to one embodiment, said spacing is partially covered by two projecting portions facing each other respectively belonging to the metal angles of the two successive angle structures,

each of the two projecting portions facing each other having a cutout formed in line with said anchoring member. Thanks to these characteristics, access of satisfactory size can be achieved while using a cutout having a relatively small section in each of the two protruding portions, which limits the influence of these cuts on the strength of metal angles.

According to one embodiment, the metal angle of an angle structure has two projecting portions which protrude from the dihedral insulating block at two opposite ends of the metal angle in the direction of the edge region. With these features, corner structures can be constructed identically, reducing manufacturing costs. According to one embodiment, said or each cutout is formed in an end edge of said projecting portion oriented transversely to the edge region. Thanks to these characteristics, the manufacture of the cuts is facilitated.

According to one embodiment, said metal angle links the two faces of the dihedral insulating block to one another.

According to one embodiment, the anchoring member disposed between the dihedral insulating blocks of the two successive angle structures cooperates with the dihedral insulating blocks of the two corner structures for retaining said dihedral insulating blocks on the support surface.

In this case the anchoring member may comprise:

a stud fixed to the support surface and projecting inwards in the space between the dihedral insulating blocks,

a support bar engaged on said stud and having two lateral portions respectively engaged with the two dihedral insulating blocks, and

a nut screwed onto the stud to tighten the support bar towards the support surface.

According to one embodiment, the support bar has a slot through which the stud passes, so that when the nut does not tighten the support bar, the support bar can be slid in a direction transverse to the Ridge area between:

a retracted position in which the support bar is housed in the spacing between the dihedral insulating blocks of the two successive angle structures to leave the location of said planar insulating panel free, and

deployed positions in which the second portion projecting beyond the dihedral insulating blocks in a direction opposite to the edge region to engage said planar insulating panel,

the nut being able to stop the sliding of the support bar by clamping the support bar towards the support surface.

According to one embodiment, the anchoring member disposed between the dihedral insulating blocks of the two successive corner structures cooperates with a plane insulating panel adjacent to the row of corner structures for retaining said plane insulating panel on the surface of support. Thanks to these characteristics, it is possible to anchor an insulating panel plane adjacent to the row of corner structures by means of one or more anchoring members located between the successive corner structures. This arrangement simplifies the positioning and implementation of the anchoring members, especially when the plane insulating panel adjacent to the row of corner structures must be dimensioned to measure and therefore can not be standardized.

In the case where the support surface is provided by a secondary barrier itself consisting of secondary angle structures and secondary planar insulating panels, this arrangement also has the advantage of allowing to position these anchors relatively close to the ridge area, especially on secondary corner structures. Thus, since the secondary planar insulating panels adjacent to the secondary corner structures do not need to carry these anchors for the primary planar insulating boards, the custom dimensioning of these secondary planar insulating boards can be facilitated.

In this case the anchoring member may comprise:

a support bar having a first portion facing the edge region engaged on said stud and a second portion projecting beyond the dihedral insulating blocks in a direction opposite to the edge region engaged with said planar insulating panel , and

According to one embodiment, the flat insulating panel adjacent to the row of corner structures comprises a layer of insulating polymeric foam sandwiched between a rigid bottom plate and a rigid cover plate, the rigid cover plate and the diaper of insulating polymer foam having a recess in the thickness of the insulating panel to find a bearing area on the inner surface of the rigid bottom plate, said recess opening on an edge of the insulating board plane parallel to the edge area and turned towards the row of corner structures, the anchoring member, in particular the second portion of the support bar, being in engagement with said support zone of the bottom plate. According to one embodiment, the recess formed in the thickness of the insulating panel is a groove oriented perpendicularly to said edge of the insulating panel plane. Such grooves may be provided at different locations, for example at the ends of the edge of the plane insulating panel facing the row of corner structures and / or in a central portion of this edge of the plane insulation board.

According to one embodiment, the planar insulating panel has a rectangular parallelepipedal shape, the recess being formed in a corner of the plane insulating panel.

According to one embodiment, the support surface carries a plurality of anchoring members distributed along the edge region and each disposed between two dihedral insulation blocks of successive angle structures and each cooperating with a respective zone of the plane insulating board adjacent to the row of corner structures for retaining said planar insulating board on the support surface.

According to one embodiment, the support surface comprises a third plane region transverse to the edge region at one end of the edge region, and a last angle structure of the angle structure row comprises, in addition to said dihedral insulating block, a third panel parallel to the third plane region and forming angles with said two panels of the dihedral insulating block, and

the metal angle of said last corner structure is extended on the planar inner surface of said third pan to form said sealing barrier at the end of the edge region of the support surface, said metal bracket joining said third pan to the dihedral insulating block, said protruding portion of the metal bracket protruding opposite the third pan in the direction of a penultimate angle structure of the row of corner structures.

According to one embodiment, said dihedral insulating block of the penultimate corner structure of the row of corner structures has a larger dimension in the direction of the edge area than corner structures in the along a central portion of the ridge zone, the metal angle of said penultimate corner structure being composed of two corner segments juxtaposed in the direction of the ridge zone and fixed on the flat interior surfaces of the dihedral insulating block. According to one embodiment, a first angle segment of said penultimate corner structure has holes for the passage of anchors for securing said dihedral insulation block to the support surface and a second angle segment. of said penultimate corner structure located on the end side of the edge region has a continuous surface.

With these features, the penultimate corner structure can quite easily be adjusted to the size of the support structure in the direction of the edge area, to account for manufacturing tolerances of this support structure.

According to one embodiment, a block of insulating material is disposed in the spacing between the dihedral insulating blocks, between the projecting portion of the metal bracket and the support surface. According to one embodiment, the block of insulating material has a passage between said cutout formed in the protruding portion of the metal bracket and said anchor disposed between the dihedral insulating blocks. With such a passage, access to the anchoring member remains possible after the establishment of the block of insulating material, which facilitates the mounting of the vessel wall.

According to one embodiment, the sealing barrier comprises a closure part arranged astride the metal angles of the two successive angle structures so as to seal the metal angles of the two corner structures,

said closure piece covering a gap between the metal angles and the cutout of said or each protruding portion which covers the spacing between the dihedral insulating blocks.

According to one embodiment, the sealing barrier in line with one or each flat region of the support surface comprises a metal membrane carrying corrugations parallel to the ridge zone and corrugations perpendicular to the ridge zone and planar areas located between said corrugations, an edge of the metal diaphragm parallel to the ridge zone being welded to the metal angles of the successive corner structures, said corrugations perpendicular to the ridge zone being aligned with interstices between the metal angles of the successive corner structures. According to one embodiment, the closure part comprises a corrugation perpendicular to the edge region aligned with a corrugation of the metal membrane and two flat portions located on either side of the corrugation and respectively welded to the metal angles. two corner structures.

The aforementioned features may be employed in the construction of an insulation barrier constructed directly on a supporting structure providing the support surface, or in the construction of a primary insulation barrier constructed on a pre-existing secondary barrier providing said surface of support.

According to one embodiment, said insulation barrier is a primary insulation barrier and said sealing barrier is a primary sealing barrier, the vessel further comprising a secondary insulation barrier having a substantially polyhedral internal surface covered a secondary sealing barrier and forming said support surface.

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 for loading or unloading such a vessel, in which a fluid is conveyed through isolated pipes from or to a floating or land storage facility to or from the tank of the vessel. ship.

According to one embodiment, the invention also provides a transfer system for a fluid, the system comprising the abovementioned vessel, insulated pipes arranged to connect the vessel installed in the hull of the vessel to a floating or ground storage facility. and a pump for driving fluid through the insulated pipelines from or to the floating or land storage facility to or from the vessel vessel. According to one embodiment, the invention also provides a manufacturing method for manufacturing a watertight and thermally insulating tank mentioned above, the method comprising:

provide a support surface,

mounting an anchoring member on the support surface,

mounting a row of corner structures along an edge region of the support surface, such that said anchor is disposed between the dihedral insulating blocks of two successive corner structures in said row,

access to said anchoring member through the cutout formed in the protruding portion of the metal angle to the right of said anchoring member, for placing said anchoring member in a gripping state in which said anchoring member retains an element of the insulation barrier on the support surface.

Brief description of the figures

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.

- Figure 1 is a schematic sectional view of a modularly constructed thermal insulation barrier with modules generally parallelepiped on a polyhedral support surface, at a ridge.

- Figure 2 is a perspective view of a sealed and thermally insulating tank wall at a corner area of the tank, the primary sealing membrane being omitted.

- Figure 3 is a view similar to Figure 2, wherein a primary corner structure is omitted but primary planar insulating panels adjacent to the primary corner structure are shown.

FIG. 4 is an enlarged perspective view showing a row of primary corner structures viewed from a section plane IV-IV of FIG. 3 and for another angle value.

FIG. 5 is an enlarged perspective view of a detail of the row of primary corner structures. FIG. 6 is a top view of a sealed and thermally insulating tank wall at a corner area of the tank, showing the location of a planar insulating board when grab bars are retracted. .

- Figure 7 is a perspective view showing an arrangement of secondary angle structures at the intersection between three walls of the vessel.

FIG. 8 is a perspective view showing an arrangement of the primary corner structures on the secondary corner structures of FIG. 7.

- Figure 9 is a perspective view of the vessel at the intersection between three walls of the vessel, partially showing the primary waterproofing membrane and a primary plane insulating panel.

- Figure 10 is a view similar to Figure 9, wherein the primary sealing membrane covering the primary plane insulating board is shown.

- Figure 11 is a perspective view of a sealed and thermally insulating tank wall according to another embodiment, at a corner region of the tank and wherein the sealing membranes are omitted.

- Figure 12 is a schematic cutaway representation of a tank of LNG tanker and a loading / unloading terminal of this tank.

Detailed description of embodiments

By convention, the terms "external" and "internal" are used to define the relative position of one element relative to another, with reference to the interior and exterior of the vessel.

The multilayer structure of a sealed and thermally insulating tank for storing liquefied natural gas will be described below. Each wall of the tank comprises, from the outside to the inside of the tank, a secondary thermally insulating barrier comprising secondary insulating elements juxtaposed and anchored to a bearing structure by secondary anchoring members, a secondary sealing membrane carried by the secondary insulating elements, a primary thermally insulating barrier comprising primary insulating elements juxtaposed and anchored to the secondary insulating elements by means of primary anchoring members 19 and a primary sealing membrane carried by the primary insulating elements and intended to be in contact with the liquefied natural gas contained in the tank.

The supporting structure may in particular be formed of self-supporting metal sheets or, more generally, any type of rigid partition having appropriate mechanical properties. The supporting structure may in particular be formed by the hull or the double hull of a ship. The carrier structure has a plurality of walls defining the general shape of the vessel, usually a polyhedral shape.

The planar areas of the tank can be made in different ways, for example according to the teaching of WO-A-2016046487 or WO-A-2017006044. In particular, a zone of angle of the vessel along an edge of the supporting structure will be described below.

In FIGS. 2 and 3, the structure of the walls of the tank is observed at an edge 10 between a first bearing wall 11 and a second bearing wall 12.

The angle formed between the first carrier wall January 1 and the second carrier wall 12 is about 90 ° in the embodiment shown. The angle may however have any other value, for example of the order of 135 °.

The secondary heat-insulating barrier has a row of secondary corner structures 13 disposed along the edge 10, a single secondary corner structure 13 being shown in Figures 2 and 3. The secondary corner structure 13 and the secondary sealing membrane 15 disposed on its inner surface 14 may be made in different ways, for example according to the teaching of WO-A-2017006044.

The secondary angle structure 13 here comprises a sandwich structure consisting of a layer of insulating polymer foam 16 sandwiched between two rigid plates 17, 18, for example of plywood. The inner plate 18 has a network of perpendicular grooves 19 intended to receive the corrugations 24 of the secondary sealing membrane 15. The corrugations 24 project outwards from the tank towards the supporting structure and are each received in a groove 19. In an alternative embodiment not shown, the orientation of the corrugations of the secondary sealing membrane is towards the inside of the tank.

The inner plate 18 is furthermore equipped with a plurality of metal plates 20, for example made of stainless steel or alloy with a low coefficient of thermal expansion, in particular invar®, intended for anchoring the edges of the diaphragm. secondary sealing. The metal plates 20 are fixed in recesses formed in the inner plate 18 and fixed thereto by screws, rivets or staples, for example. Alternatively, the metal plates 20 are fixed directly on the layer of insulating polymer foam 16, for example by gluing.

The inner plate 18 is also equipped with anchoring plates 21 intended to ensure the attachment of primary angle structures 30 against the secondary angle structure 13. The anchor plates 21 are for example glued to the inner plate 18 and or fixed thereto by screws, rivets or staples for example.

Furthermore, the secondary waterproofing membrane 15 has a plurality of orifices through each of which passes an anchoring member for anchoring the primary corner structures 30. A blind nut 22 passes through each of the orifices and presents on its outer periphery a thread cooperating with a threaded bore 23 formed in one of the anchor plates 21. Furthermore, the blind nut 22 has a threaded blind bore for receiving a stud for fixing the primary angle structures 30 The blind nut 22 further comprises a flange for sandwiching the secondary sealing membrane 15 between said flange and the anchoring plate 21. The periphery of this flange is welded to the secondary sealing membrane 15 in order to to seal.

The primary thermally insulating barrier comprises along the edge 10 of the vessel a plurality of primary corner structures 30. The primary corner structure 30 is a preassembled assembly comprising a dihedral insulating block 31 and an angle iron 32. dihedral insulation 31 has an inner face on which the angle 32 rests and an outer face resting against the secondary sealing membrane 15. The dihedral insulation block 31 has a composite structure in its thickness, comprising a layer of insulating polymer foam 33 taken in sandwich between two plywood plates 34, 35 bonded to said polymeric foam layer 33.

The brackets 32 are metal angles, for example, made of stainless steel. The bracket 32 has two wings resting against the inner face of the dihedral insulation block 31. Each wing of an angle bracket 32 has unrepresented studs which are welded to the outer face of said wing and project into the interior of the tank for fix the bracket 32 to the dihedral insulation block 31, before mounting the primary corner structure 30 in the tank.

Each wing of the bracket 32 also has a stud 36 on its inner face, projecting towards the inside of the tank. The studs 36 make it possible to anchor a welding equipment during the welding of the elements of the primary waterproofing membrane on the brackets 32.

As described in WO-A-2017006044, the angle 32 is provided with orifices 37, for example eight in number by angle 32, for mounting nuts on studs (not shown) carried by the plates 21, in order to securing the primary corner structure 30 to the secondary corner structure 13.

As best seen in Figures 2 and 4, the primary corner structures 30 are disposed on the secondary corner structures 13 in the form of a row along the edge 10. In this row, two primary corner structures 30 successive have a space 38 between the two dihedral insulating blocks 31. Generally, insulating joint elements 39 are inserted in the space 38 between the two dihedral insulating blocks 31, so as to ensure continuity of the thermal insulation.

In at least some of the spaces 38, the secondary angle structure 13 may carry an anchoring member for cooperating with a primary insulating member. This case will be described more specifically with reference to FIGS. 3 to 5. The anchoring element as a whole is cut in its median plane of symmetry in FIG. 4, so that the half-view is sufficient to understand its structure. .

In this embodiment, the anchoring member comprises a plate 40 fixed on the inner surface of the secondary angle structure 13 between two plates 21. The plate 40 can be fixed on the secondary angle structure 13 of different such as turntables 21. It has a tapped hole 41 for receiving a blind nut 42 shown in half-view in FIG. 4. The plate 40 may be present at the right of each space 38 or at the right of some, for example one in three, spaces 38.

The blind nut 42 passes through an orifice of the secondary sealing membrane, not shown, and has on its outer periphery a thread 43 cooperating with the threaded hole 41 formed in the plate 40. Moreover, the blind nut 42 has a blind bore. threaded 44 receiving a stud 45. The blind nut 42 further comprises a collar 46 for sandwiching the secondary sealing membrane between said collar and the plate 40. The periphery of this collar is welded to the sealing membrane secondary 15 to ensure sealing.

As can be seen in FIG. 4, the stud 45 protrudes inwards in the space 38 between the two dihedral insulating blocks 31 and serves to fix a support bar 50 oriented perpendicular to the edge 10. The bar support 50 here has a U-shaped section whose base is turned towards the supporting structure. In the mounted state as shown, a first portion of the support bar 50 extends in the space 38 between the two dihedral insulating blocks 31 and has a slot 58 through which the stud 45 passes. the stud 45 makes it possible to tighten the support bar 50 towards the internal surface of the secondary angle structure 13.

A second portion 51 of the support bar 50 protrudes beyond the row of primary corner structures 30 to abut a planar primary insulating panel 29 adjacent to the row of primary corner structures 30. slot length 58 allows a length adjustment of the second portion 51 projecting beyond the row of primary corner structures 30.

Preferably, the slot 58 whose two ends 58a and 58b are indicated in the sectional view of FIG. 4, is long enough to allow the support bar 50 to be completely retracted into the space 38 between the two insulating blocks. Thus, before the nut 47 is tightened, it is possible to slide the support bar 50 between this retracted position (shown in FIG. 6), which facilitates the installation of the primary plane insulating panel 29 by completely releasing its location indicated in phantom at the number 99, and the extended position illustrated in FIG. 4. The deployment movement of the support bar 50 is shown schematically by the arrow 98 in FIG. 6. In one embodiment, the length of the planar primary insulating panel 29 is nine times the width of the primary corner structure 30, so that four support bars spaced apart by an interval of three times the width of the the primary corner structure 30 engages the plane primary insulating board 29 along its edge turned towards the edge, namely two support bars 50 at both ends of this edge, i.e. at two corners of the plane primary insulating panel 29, and two support bars in a central zone of the edge of the primary plane insulating panel 29. This central zone is shown in FIG.

As partially shown in FIG. 3, the plane primary insulating panel 29 has the general shape of a rectangular parallelepiped with a longitudinal edge 26 parallel to the edge 10. The flat primary insulating panel 29 has, for example, a composite structure consisting of a layer of insulating polymer foam sandwiched between a rigid bottom plate, an exposed area 28 of which is apparent, and a rigid cover plate 25. The rigid cover plate 25 and the insulating polymeric foam layer are hollowed out with a groove 27 extending perpendicular to the edge 10 to the right of the plate 20 and opening on the longitudinal edge 26 to discover the uncovered area 28 of the rigid bottom plate.

In the mounted state, the second portion 51 of the support bar 50 is engaged in the groove 27 and bears on the uncovered area 28 of the rigid bottom plate, possibly via a shim thick 48. Another shim 49 may be interposed between the other end of the support bar 50 and the secondary membrane (not shown). The shims 48 and 49 are dimensioned to ensure the parallelism between the support bar 50 and the bottom plate of the primary plane insulating panel 29. They are made of a sufficiently soft material to avoid the risk of punching, marking or For example, they may be made of plywood, plastic or epoxy resin.

The support bar 50 mounted in this way has several advantages: the second portion 51 is a length cantilever substantially parallel to the flat wall of the vessel which bears on the primary insulating panel plane 29, preferably to distance from the edge of this panel. It thus makes it possible to retain the primary plane insulation panel 29 on the secondary membrane without requiring any development. complex on the primary insulation board plane 29: it is enough to clear a flat portion of the bottom plate.

In addition, the length of the second portion 51 is easily adjustable by sliding the stud 45 in the length of the slot 58. This arrangement is therefore easily adapted to planar insulating panels having different dimensions or grooves 27 having different lengths. The length of the groove 27 can in particular be shortened following cutting of the edge 26 to reduce the width of the insulating panel 29.

In addition, since the support bar 50 is anchored to a stud carried by the secondary angle structure 13, its position is not sensitive to the dimensioning of the secondary planar insulating panels (not shown) adjacent to the structure of the secondary structure. Secondary angle 13. This arrangement is therefore easily adapted to secondary insulating panels planes of different dimensions.

As can be seen in FIG. 4, each bracket 32 has two projecting flanges 53 which protrude from the dihedral insulating block 31 at two ends of the bracket 32 opposite in the direction of the edge 10. Thus, the space 38 between the two dihedral insulating blocks 31 is partially covered by the two projecting flanges 53 on either side thereof.

To preserve access to the anchoring member disposed in the space 38, at least each of the two projecting flanges 53 on either side of the anchoring member is provided with a cutout 54 which is located in line with the stud 45 and which is formed in the end edge 55 oriented transversely to the edge 10.

Optionally, as sketched in FIG. 2, all the projecting edges 53 of all the angles 32 may have this cutout 54 to standardize the manufacturing.

As best seen in Figure 5, the cutouts 54 serve to provide sufficient space between the two projecting flanges 53 for the passage of a clamping tool 60, for example a pipe wrench having a cylindrical head 61 or a screwdriver. The depth of the cutout 54 in the direction of the edge 10 can therefore be dimensioned to provide a distance D slightly greater than the diameter of the cylindrical head 61 between the bottoms of the two cutouts 54 vis-à-vis. The length of the cutout 54 along the end edge 55 may be substantially equal to the same distance D, for example about 30mm.

The assembly sequence of the corner area of the tank will now be briefly described:

mounting the secondary insulating barrier and the secondary waterproof membrane 15, including the cap nuts 42

- Placement of the support bars 50 in the retracted position, the slot 58 of the support bar being positioned in line with the blind nut 42.

- Inserting and screwing the stud 45 in the blind nut 42 through the slot 58 of the support bar 50, setting the nut 47 on the stud 45 in the untightened position

placing the insulating joints 39 between the locations of the primary corner structures 30. Where the support bar 50 is present, the insulating joint 39 has at its base a pin inserted into the U-shaped hollow section of the support bar 50. The insulating joint 39 also has a cylindrical well 56 in line with the blind nut 42 to receive the stud 45 and the nut 47.

attaching the primary corner structures 30 to the secondary corner structures 13, on either side of the insulating joints 39. laying planar primary insulation panels 29 adjacent to the row of primary corner structures 30

Displacement of the support bars 50 in the deployed position, the insulating joint 39 remaining immobilized by the stud 45 engaged in the cylindrical well 56

- Screwing the nut 47 on the stud 45 through the cutouts 54 of the brackets 32 and the cylindrical well 56 of the insulating joint 39, to achieve the tightening of the support bar 50

Inserting a cylindrical plug 57 into the cylindrical well 56 to close it.

- Installation of the primary waterproofing membrane.

The construction of the planar portions of the vessel wall on both sides of an edge can be performed identically or differently, and symmetrically or asymmetrically. Moreover, if a single angle of the tank has been described above, the other angles of the tank may have the same or different arrangement.

Referring to Figures 7 to 10, we will now describe the structure of the vessel wall at one end of the edge 10, that is to say at the intersection between three planar walls. The three walls which are here represented constitute respectively a bottom wall, an end wall and a lower oblique wall. The lower oblique wall forms an angle of 135 ° with the bottom wall. The lower oblique wall and the bottom wall are perpendicular to the end wall. Such an arrangement corresponds for example to a tank which has a generally polyhedral shape and which comprises two end walls of octagonal shape which are connected to each other by eight walls, namely a bottom wall and a wall of horizontal ceilings, two vertical side walls, two upper oblique walls each connecting one of the side walls to the ceiling wall and two lower oblique walls each connecting one of the side walls to the bottom wall.

In this zone, as shown in FIG. 7, the row of secondary corner structures 13 ends in a last secondary angle structure 113 which is formed of a set of three insulating panels which are respectively fixed against the supporting structure of each of the three supporting walls. The three insulating panels of the last secondary corner structure 1 13 each have a sandwich structure identical to that of the secondary corner structures 13, namely constituted by a layer of insulating polymer foam 116 sandwiched between two rigid plates 117, 118 for example plywood.

On each of the three insulating panels of the last secondary angle structure 113, the rigid plate 118 carries anchor plates 121 and 140 whose structures and functions are identical to those of the anchor plates 21 and 40 described above. In particular, the anchor plates 121 make it possible to fix a final primary angle structure 130 (FIG.7) on the last secondary angle structure 113.

The plate 40 makes it possible to fix an anchoring member in a space between the last primary corner structure 130 and a second-to-last primary corner structure 230 (FIG.7) of the row of primary corner structures. This anchoring member comprises a pin 145 engaged in a slot 158 of a support bar 150 visible in FIG. 9. Fig. 8 is also a view of the end region of the ridge, showing in addition the primary corner structures mounted on the secondary corner structures of Fig. 7. The secondary sealing membrane is entirely omitted for simplify the representation.

As shown, the last primary angle structure 130 of the row consists of three insulating blocks respectively resting against each of the three insulating panels of the last secondary angle structure 113. Moreover, the insulating blocks of the last structure of primary angle 130 each comprise an inner face on which rests an angle bracket 132 whose general structure is similar to the metal angle 32 of the primary angle structure 30, except for the presence of a third flange 100 parallel to the wall oblique inferior. The angle bracket 132 comprises in particular studs 136, orifices 137 and flanges 153 whose structures and functions are similar to those of studs 36, orifices 37 and rims 53 described above.

The penultimate primary corner structure 230 is shown by employing reference numerals increased by 200 for elements similar or identical to those of the primary corner structure 30. The dihedral insulating block 231 is longer than the insulating block dihedral 31 and carries on its inner surface two successive metal angles in the direction of the edge. The metal angle 232 is substantially identical to the metal angle 32 of the primary angle structure 30, but because the dihedral insulating block 231 is elongate toward the last primary corner structure 130, it may have a larger dimension. long along the edge 10 and it extends only one side (not shown) of the dihedral insulating block 231.

The metal angle 65 is placed next to the metal angle 232 with a small gap between them and fixed on the dihedral insulating block 231 in the same manner as the metal angle 32 of the primary angle structure 30. The metal angle 65 presents a protruding flange 253 protruding from the dihedral insulating block 231 in the direction of the ridge 10 above the space 138. The space 138 is partially covered by the two projecting flanges 153 and 253 of the wall other of it. The protruding flange 153 and / or the protruding flange 253 may include a cutout to facilitate access to the anchor member in the space 138. Here, a cutout 254 is present only in the projecting flange 253.

Furthermore, the fixing of the penultimate primary angle structure 230 on the secondary insulating barrier is carried out only at the furthest portion of the last primary corner structure 130, namely the portion carrying the angle metal 232 which is fixed on a penultimate secondary structure of secondary angle 13 underlying in the same manner as described above For this, the metal angle 232 also has orifices 237.

On the other hand, the metal angle 65 does not have orifices and can be continuous, since the portion of the dihedral insulating block 231 facing the last primary angle structure 130 spans the gap 66 between the penultimate structure of the secondary angle 13 and the last secondary angle structure 113 and extends to the last secondary angle structure 113 without being attached thereto.

This arrangement has the advantage of being independent of the precise size of the gap 66 in the secondary insulation barrier, which can be easily adjusted to compensate for manufacturing tolerances.

In addition, to adjust the primary insulation barrier to the dimensional tolerances of manufacture of the supporting structure, it is possible to cut to size the penultimate primary angle structure 230, namely to cut the end of the dihedral insulating block. 231 and the end of the metal angle 65 turned towards the last primary angle structure 130. Given the absence of attachment of this end portion to the secondary insulation barrier, this cutting entails no complication . In this case the cut 254 is added after cutting the metal angle 65 to the desired length.

FIG. 9 shows the same zone of the tank as FIG. 8, but with the addition of a final plane primary insulating panel 129 adjacent to the penultimate primary corner structure 230. This primary plane insulating panel 129 presents , similarly to the groove 27 of Figure 3, a recess 127 made in line with a corner area of the rigid bottom plate (not shown) to discover said corner area. FIG. 9 also shows the support bar 150 which is engaged in the recess 127 and is based on the uncovered area as previously described.

Referring to Figures 9 and 10, we will now describe the structure of the primary waterproofing membrane at the corners of the tank.

The primary waterproofing membrane is for example a membrane having two series of mutually perpendicular corrugations. It can be performed essentially as described in WO-A-2017006044. Metal sheets 67 of the primary sealing membrane bordering an edge are welded along their edge directed towards the edge on the metal angles 32, 232, 65, 132. Moreover, metal corner pieces 68, 168, 268 , are welded astride each interface between two successive metal angles 32, 232, 65, 132.

The corner pieces 68, 168, 268 cover the orifices 37, 137, 237 and the cutouts 54, 254 of the metal angles provide the continuity of the corrugations of the primary waterproofing membrane oriented perpendicularly to the edge 10.

Figure 1 illustrates another embodiment of the vessel wall along the edge 10. The primary and secondary sealing membranes are omitted to simplify the representation. Elements similar or identical to those of FIGS. 2 to 4 bear the same reference number increased by 300 and will only be described to the extent that they differ from those of FIGS. 2 to 4.

In this embodiment, the primary angle structure 330 is fixed to the secondary angle structure 313 by means of pins 345 disposed in each space 338 between two dihedral insulation blocks 331. For this, the rigid plate 334 is slightly more wide than the polymeric foam layer 333 so as to discover two lateral flanges of the rigid plate 334.

A support bar 350 has a bore, which can be oblong, traversed by the stud 345 and bears on the lateral flanges of the rigid plate 334 of the two primary angle structure 330 between which the stud 345 is disposed. Thus, each primary corner structure 330 is retained by two support bars 350 in engagement with the two lateral flanges of its rigid plate 334. A not shown nut is screwed onto each stud 345 to tighten the support bar 350 by direction of the supporting structure. Cutouts 354 in the corners of the angles metal 332 facilitate the mounting of the stud 345 and then the establishment of the nut in the manner described above.

Because of this mode of attachment of the primary angle structures 330, the orifices are removed in the metal angle 332, which can be continuous.

For anchoring the plane primary insulation board 329 adjacent to the primary corner structure row 330 on the secondary barrier, a row of studs 69 may be provided on each side of the row of primary corner structures 330. This may require to provide a larger secondary angle structure 313, as shown.

In one embodiment, the secondary insulating barrier and the secondary sealing membrane are removed and the studs which anchor the primary insulating barrier are carried directly by the carrier walls 11, 12.

The technique described above for producing a sealed and thermally insulating tank for storing a fluid can be used in different types of tanks, for example to form an LNG tank in a land installation or in a floating structure such as a LNG tanker. Or other.

The technique illustrated above in the context of a truly polyhedral support surface, in which plane portions join at edges, is also applicable to an approximately polyhedral support surface which, instead of the ridges, would have rounded portions providing a connection between planar portions. The term edge area is used to designate the connection between two planar portions in the two contexts and may correspond to a real edge or a rounded portion between the two planar portions.

Referring to Figure 12, a cutaway 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 72 of the ship, and two insulating barriers arranged respectively between the primary watertight barrier and the secondary watertight barrier and between the secondary watertight barrier and the double hull 72. In a manner known per se, loading / unloading lines 73 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. 12 represents an example of a marine terminal comprising a loading and unloading station 75, an underwater pipe 76 and an onshore installation 77. The loading and unloading station 75 is a fixed off-shore installation comprising an arm mobile 74 and a tower 78 which supports the movable 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 can be adapted to 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. liquefied gas storage tanks 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 onshore installation 77 over a large distance, for example 5 km, which makes it possible to keep the tanker vessel 70 at 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 for storing a fluid, the sealed and thermally insulating vessel having an insulation barrier and a sealing barrier disposed on an inner surface of the insulation barrier, the insulation barrier being disposed on a support surface carrying anchoring members and retained on the support surface by said anchoring members, the support surface having at least two planar regions forming an angle therebetween and joining at a ridge area (10),

wherein the insulation barrier has a row of corner structures (30, 130, 230, 330) disposed along said edge region of the support surface and planar insulating panels (29, 129, 329) disposed on the planar regions of the support surface on either side of the row of corner structures,

wherein at least one said angle structure comprises:

- a dihedral insulating block (31, 231, 331) having two sides respectively parallel to the plane regions and forming an angle between them, said pan having a flat outer surface bearing against the corresponding flat region of the support surface and an inner surface planar parallel to said corresponding planar region and spaced from said planar outer surface in a thickness direction, and

- a metal angle (32, 65, 132, 232, 332) fixed on the flat inner surfaces of the dihedral insulating block to form said sealing barrier to the right of the edge region of the support surface, the metal angle having a protruding portion (53, 153, 253, 353) projecting from the dihedral insulating block in the direction of the edge region,

wherein two successive corner structures in said row are arranged to have a spacing (38, 138, 338) in the direction of the edge area between the dihedral insulating blocks, said spacing being at least partially covered by the protruding portion (53, 153, 253, 353) of the metal angle of at least one of the two successive angle structures,

wherein the support surface carries a said anchoring member (45, 145, 345) disposed between the dihedral insulating blocks of the two corner structures, said at least one of the two successive corner structures having a cut-out (54, 254, 354) formed in the projecting portion of the metal angle to the right of said member anchor disposed between the dihedral insulating blocks, to provide access to said anchor member (45, 145, 345).

2. Tank according to claim 1, wherein said spacing is partially covered by two projecting portions (53, 153, 253, 353) facing each other respectively belonging to the metal angles of the two successive angle structures,

each of the two projecting portions facing each other having a cutout (54, 254, 354) formed in line with said anchoring member.

A vessel according to any one of claims 1 to 2, wherein said cutout (54, 254, 354) is formed in an end edge of said projecting portion oriented transversely to the edge region.

4. Tank according to any one of claims 1 to 3, wherein the anchoring member (345, 350) disposed between the dihedral insulation blocks (331) of the two successive angle structures (330) cooperates with the blocks. dihedral insulators of the two corner structures for retaining said dihedral insulating blocks (331) on the support surface.

5. Tank according to claim 4, wherein the anchoring member comprises:

a stud (345) attached to the support surface and projecting inwardly into the space between the dihedral insulating blocks,

a support bar (350) engaged on said stud and having two lateral portions respectively engaged with the two dihedral insulating blocks (331), and

a nut screwed onto the stud (345) to tighten the support bar (350) towards the support surface.

6. Tank according to any one of claims 1 to 5, wherein the anchoring member disposed between the dihedral insulating blocks (31, 231) of the two successive corner structures cooperates with a planar insulating panel (29, 129 ) adjacent to the row of corner structures for retaining said planar insulating board on the support surface.

The vessel of claim 6, wherein the anchor comprises:

a stud (45, 145) attached to the support surface and projecting inwards in the space between the dihedral insulating blocks,

a support bar (50, 150) having a first portion facing the edge region engaged on said stud and a second portion (51) projecting beyond the dihedral insulating blocks (31, 231) in an opposite direction at the edge region engaged with said planar insulation board (29, 129), and

a nut (47) screwed onto the stud and able to clamp the support bar (50, 150) towards the support surface.

8. A tank according to claim 7, wherein the support bar has a slot through which the bolt passes, so that when the nut does not clamp the support bar, the support bar can be slid into a groove. transverse direction to the ridge zone between:

- a retracted position in which the support bar is housed in the spacing between the dihedral insulating blocks (31, 231) of the two successive angle structures to leave free the location of said planar insulating panel (29, 129), and

deployed positions in which the second portion (51) projecting beyond the dihedral insulating blocks (31, 231) in a direction opposite to the edge region to engage said planar insulation board (29, 129) .

A vessel according to any one of claims 6 to 8, wherein the planar insulation board (29,129) adjacent to the row of corner structures comprises a layer of insulating polymeric foam sandwiched between a rigid bottom plate and a rigid cover plate (25), the rigid cover plate and the insulating polymer foam layer having a recess (27, 127) formed in the thickness of the insulating panel to reveal a bearing area (28) on the inner surface of the rigid bottom plate, said recess opening on an edge (26) of the insulating board plane parallel to the edge area and facing the row of corner structures, the anchoring member being engaged with said area support (28) of the bottom plate.

10. Tank according to claim 9, wherein the recess formed in the thickness of the insulating panel is a groove (27) oriented perpendicularly to said edge (26) of the insulating panel plane.

11. Tank according to claim 9 or 10, wherein the planar insulating panel has a rectangular parallelepiped shape, the recess (127) being formed in a corner of the plane insulating panel.

A vessel according to any one of claims 6 to 11, wherein the support surface carries a plurality of anchors (45, 145) distributed along the ridge zone (10) and each disposed between two dihedral insulation blocks of successive angle structures (30, 130, 230) and each cooperating with a respective area of the plane insulating panel (29, 129) adjacent to the row of corner structures for retaining said plane insulating panel on the support surface.

A vessel according to any one of claims 1 to 12, wherein the support surface comprises a third planar region transverse to the ridge zone at one end of the ridge zone (10), wherein a last structure angle (130) of the row of corner structures comprises, in addition to said dihedral insulating block, a third panel (100) parallel to the third plane region and forming angles with said two panels of the dihedral insulating block (130), and wherein the metal angle (132) of said last corner structure (130) extends on the planar inner surface of said third pan to form said sealing barrier at the end of the edge region of the support surface, said metal bracket connecting said third panel to the dihedral insulating block, said projecting portion (153) of the metal bracket (132) protruding away from the third panel (100) in the direction of a penultimate angle structure (230) of the row of corner structures.

The vessel according to claim 13, wherein said dihedral insulating block (231) of the first-to-last angle structure (230) of the row of corner structures has a larger dimension in the direction of the only corner structures located along a central portion of the ridge zone, the metal angle of said penultimate corner structure being composed of two corner segments (232, 65) juxtaposed according to the direction of the ridge zone and fixed on the flat inner surfaces of the dihedral insulating block (231).

The vessel of claim 14, wherein a first angle segment (232) of said penultimate corner structure has holes (237) for passage of anchors for securing said dihedral insulating block ( 231) on the support surface and a second angle segment (65) of said second-to-last angle structure located on the end-side side of the edge region has a continuous surface.

Tank according to any one of claims 1 to 15, wherein a block of insulating material (39) is arranged in the spacing (38, 138, 338) between the dielectric insulating blocks between the projecting portion (53, 153 , 253, 353) of the metal bracket and the support surface, the block of insulating material (39) having a passage (56) between said cutout (54, 254, 354) formed in the protruding portion of the metal bracket and said anchoring member disposed between the dihedral insulating blocks.

17. Tank according to any one of claims 1 to 16, wherein the sealing barrier comprises a closure piece (68) arranged astride the metal angles (32, 132, 232, 65) of the two structures of successive angles so as to sealingly connect the metal angles of the two corner structures,

said closure piece (68) covering a gap between the metal angles and the cutout (54, 254, 354) of said or each protruding portion which overlaps the spacing between the dihedral insulating blocks.

18. A tank according to any one of claims 1 to 17, wherein the sealing barrier in line with one or each flat region of the support surface comprises a metal membrane (67) carrying corrugations parallel to the zone d ridge and corrugations perpendicular to the ridge zone and planar areas between said ripples, an edge of the metal diaphragm (67) parallel to the ridge zone being welded to the metal angles (32, 232, 65) successive corner structures, said corrugations perpendicular to the ridge zone being aligned with interstices located between the metal angles of the successive corner structures.

19. Tank according to claims 18 and 17 taken in combination, wherein the closure piece (68, 168) comprises a corrugation perpendicular to the ridge zone aligned with a corrugation of the metal membrane and two flat portions located on the side and other of the corrugation and respectively welded to the metal angles of the two corner structures.

20. A vessel according to any one of claims 1 to 19, wherein said insulation barrier is a primary insulation barrier and said sealing barrier is a primary sealing barrier, the vessel further comprising a barrier of insulation. secondary insulation (13, 113, 213) having an inner surface substantially polyhedral covered with a secondary sealing barrier (15) and forming said support surface.

21. Vessel (70) for the transport of a fluid, the vessel comprising a double hull (72) and a tank (71) according to any one of claims 1 to 20 disposed in the double hull.

22. Transfer system for a fluid, 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 of the ship. at a floating or land storage facility (77) and a pump for driving fluid through the insulated pipelines from or to the floating or land storage facility to or from the vessel vessel.

23. A method of loading or unloading a ship (70) according to claim 21, wherein a fluid is conveyed through isolated ducts (73, 79, 76, 81) to or from a floating or land storage facility ( 77) to or from the vessel vessel (71).

24. Manufacturing process for manufacturing a sealed and thermally insulating tank according to one of claims 1 to 20, the method comprising:

provide a support surface,

mounting an anchoring member (45, 145, 345) on the support surface,

mounting a row of corner structures (30, 130, 230, 330) along an edge region of the support surface, so that said anchoring member (45, 145, 345) is disposed between the dihedral insulating blocks of two successive corner structures in said row,

accessing said anchoring member (45, 145, 345) through the cutout (54, 254, 354) formed in the protruding portion of the metal angle to the right of said anchor member, for placing said anchor member in a gripping state in which said anchoring member retains an element of the insulation barrier on the support surface.