JP7254957B2 - Hermetically sealed insulated tank - Google Patents

Description

The present invention relates to the field of closed and insulated tanks with membranes. In particular, the present invention is for example a tank for transporting liquefied petroleum gas (aka LPG) having a temperature of -50°C to 0°C or a tank for transporting liquefied natural gas (LNG) at around -162°C at atmospheric pressure. It relates to the field of closed and insulated tanks, such as tanks, for storing and/or transporting liquefied gases at low temperatures. These tanks can be installed on land or on floating structures. In the case of floating structures, the tanks may be intended for the transport of liquefied gas or for the containment of liquefied natural gas used as fuel to propel the floating structure.

In one embodiment, the liquefied gas is LNG, a mixture with a high methane content stored at a temperature of about -162°C at atmospheric pressure. Other liquefied gases are also conceivable, in particular ethane, propane, butane or ethylene. The liquefied gas can also be stored under pressure, for example at a relative pressure of 2 bar to 20 bar, in particular a relative pressure close to 2 bar.

WO2014096600 discloses a closed and insulated tank for storing liquefied natural gas, which is arranged in a support structure and is provided with a multi-layered wall, i.e. from the outside of the tank to the inside, a secondary insulation barrier secured to the support structure; a secondary containment membrane supported by the secondary insulation barrier; a primary insulation barrier resting on the secondary containment membrane; a primary sealing membrane configured to contact the stored liquefied natural gas.

each of the primary and secondary insulation barriers is a set of generally parallelepiped-shaped insulation panels, a primary insulation panel and a secondary insulation panel, respectively, juxtaposed and thus forming supporting surfaces for the respective sealing membranes; include. The insulation panels are secured to the support structure and anchored onto the support structure by anchoring devices located at the corners of the primary and secondary insulation panels. Thus, each anchoring device interacts with four adjacent secondary insulation panel corners and four adjacent primary insulation panel corners to hold them to the support structure.

WO2013104850 describes a closed insulated tank comprising a multi-layer construction in which the corners of the insulation panels of the primary insulation barrier are not aligned with the corners of the insulation panels of the secondary insulation barrier. In such tanks, a primary anchoring device that interacts with the primary insulation panel is fixed to a plate that is fixed to the secondary insulation panel. The primary anchoring device and the primary insulation panel are thus secured to the support structure by the secondary insulation panel.

In all cases the secondary insulation panel is subject to deformation and/or movement. Specifically, secondary insulation panels are subjected to thermal gradients which may cause them to bend due to differential shrinkage phenomena. Additionally, deformation of the support structure causes deformation and/or movement of the secondary insulation panel. This is especially the case when the support structure consists of the inner hull of the floating structure. Also, if the hull defines a ballast compartment, movement of ballast liquid within the ballast compartment is also likely to cause substantial deformation of the support structure and thus deformation and/or movement of the secondary insulation panels fixed on the support structure. .

In addition, movement of the liquid contained within the tank can create stress on the primary sealing membrane, particularly if the primary sealing membrane includes protrusions such as corrugations. These stresses are transferred to the primary insulation panel to which the primary sealing membrane is fixed, tending to cause the primary insulation panel to move laterally. The result is stress concentration in the primary anchoring device.

However, the primary anchoring device includes a collar that is sealingly welded to the secondary sealing membrane to ensure the tightness of the secondary sealing membrane. The collar is rigidly secured to studs carrying bearing elements that interact with the corresponding primary insulation panel or panels. This connection between the primary anchoring device and the secondary sealing membrane results in a weld between the collar and the secondary sealing membrane upon deformation and/or movement of the secondary insulation panel and/or movement of the primary insulation panel. The welds and the secondary sealing membrane are likely to be damaged due to stress concentration in the joint.

In particular, in the case of primary anchoring devices that are secured to secondary insulation panels, deformation and/or movement of the secondary insulation panel causes movement of the primary anchoring devices. This movement of the primary anchoring device is transferred to the collar, which is rigidly secured to the stud, causing stress in the sealing connection between the collar and the secondary sealing membrane. Such stresses can damage the secondary sealing membrane and/or the sealing connection between the collar and the secondary sealing membrane, thereby compromising the sealability of the secondary sealing membrane.

The idea forming the basis of the invention is to limit the concentration of stresses at the connection between the secondary sealing membrane and the primary anchoring members of the primary insulation panel. The idea forming the basis of the invention is to create a flexible sealing connection between the primary anchoring member and the secondary sealing membrane. The idea forming the basis of the invention is thus to allow relative movement between the secondary sealing membrane and the primary anchoring member. The idea forming the basis of the invention is that the primary anchoring member is either fixed directly to the support structure, for example by being made in conjunction with the secondary anchoring member, or by being fixed to the secondary insulation panel, for example. Whether indirectly fixed to a support structure or not, it is to allow said movement. Another idea forming the basis of the invention is therefore to allow relative movement between the secondary insulation panel to which the primary anchoring member is fixed and the secondary sealing membrane.

In one embodiment, the present invention provides a closed insulated tank comprising a tank wall, the tank wall continuing in the thickness direction of the tank wall from the outside of the closed insulated tank to the inside of the closed insulated tank and a supporting wall a secondary insulation barrier configured to be secured to the secondary insulation barrier; a secondary sealing membrane resting on the secondary insulation barrier; a primary insulation barrier resting on the secondary sealing membrane; and a primary sealing membrane configured to contact the product contained within the sealed insulated tank, the primary insulation barrier comprising a plurality of juxtaposed primary insulation panels, the sealed insulated tank directly on the support wall. or a plurality of primary anchor members configured to be indirectly retained, each primary anchor member interacting with at least one primary insulation panel of the plurality of primary insulation panels to cause the at least one configured to retain the primary insulation panel on the secondary sealing membrane, one or more or each of the primary anchor members being configured to be directly or indirectly retained on the support wall; a stem extending through the thickness of the tank wall toward the sealing membrane, the stem passing through an opening in the secondary sealing membrane; and a seal washer engaging the stem between the bearing element and an opening in the secondary sealing membrane, the seal washer having a central opening through which the stem passes. and a seal washer sealingly secured to the secondary sealing membrane around the aperture in the secondary sealing membrane, for example by a collar of the seal washer, and to allow relative movement between the seal washer and the stem. a deformable seal sealingly connecting the seal washer and the stem.

Due to the above features, relative movement between the secondary sealing membrane and the primary anchoring member does not risk damaging the secondary sealing membrane or the sealing connection between the primary anchoring member and the secondary sealing membrane. , it becomes possible. In particular, the deformable sealing portion forms a flexible sealing connection with the stem of the primary anchor member on one side and with the sealing washer on the other side, thereby sealing the secondary sealing membrane. sex is guaranteed. Accordingly, such primary anchoring members allow relative movement between the secondary insulation panel and/or the primary insulation panel and the secondary sealing membrane to affect the secondary sealing membrane or between the primary anchoring member and the secondary sealing membrane. without the risk of damaging the hermetic connection between the

In one embodiment, the tank described above may include one or more of the following features.

The primary anchoring members described above may be used throughout the tank wall or may be used only in localized portions of the tank wall, such as ballast areas. In one embodiment, the tank wall has a vertical component that defines the height of the tank wall in the direction of gravity, the tank wall has a plurality of said primary anchor members, each primary anchor member comprising: A plurality of primary anchoring members comprising a base, a stem, a bearing element, a sealing washer and a deformable sealing portion are arranged in a lower portion of the tank wall, e.g. 3.

In one embodiment the tank wall is a first tank wall and said tank further comprises a second tank wall, said first tank wall and said second tank wall forming a rim of said tank and said first has a plurality of said primary anchor members, each primary anchor member comprising a base, a stem, a bearing element, a seal washer and a deformable seal portion as described above, and a plurality of A primary anchor member is positioned at a distance from the edge of the tank equal to or less than a predetermined threshold. For example, the predetermined threshold corresponds to a width of five insulation panels, and the plurality of primary anchor members are arranged to hold, for example, five consecutive primary insulation panels in a direction perpendicular to said edge.

A portion of the tank wall located at the bottom of the tank may be affected by, for example, the weight of the liquid being transported or, in practice, for example in the case of lateral tank walls fixed to the cofferdam wall, the ballast in the carrier. Especially exposed to high stress. Similarly, the rim area of the tank is also subject to particularly high stresses, including the pressure created by the water in the ballast of the carrier. These stresses tend to cause relative movement between the primary and/or secondary insulation barriers on one side and the secondary sealing membranes at the bottom and/or rim of the tank on the other side. Thus, with the primary anchoring member arrangement described above, the risk of damage to the secondary sealing membrane is limited by the flexibility of the connection between the primary anchoring member and the secondary sealing membrane.

Primary insulation panels can be manufactured in a variety of ways. In one embodiment, the primary insulation panel is parallelepiped-shaped.

In one embodiment, the primary insulation panel comprises a bottom plate, a cover plate and an insulation lining interposed between the bottom plate and the cover plate.

Bearing elements can support various portions of the primary insulation panel. In one embodiment, the bearing elements directly support the primary insulation panel, for example the bottom plate of the primary insulation panel. In one embodiment, the bearing elements indirectly support the primary insulation panel, for example via wedges inserted between the bearing elements and elements of the primary insulation panel, such as the bottom plate of the primary insulation panel.

In one embodiment, the corners of the primary insulation panel are provided with recesses that expose bearing surfaces facing the interior of the tank. In one embodiment, the bearing elements of the primary anchor member directly or indirectly support the bearing surface of the primary insulation panel. In one embodiment, the recess is formed in the cover plate and the insulating lining. In one embodiment, the bearing surface is formed by a portion of the bottom plate protruding from recesses formed in the insulating lining and cover plate. In one embodiment, the bearing surface is formed by a wedge arranged between the bearing element and a portion of the bottom plate protruding from a recess formed in the insulating lining and cover plate.

In one embodiment, the primary anchor members interact with the corners of adjacent primary insulation panels, such as four corner-adjacent panels, to secure these adjacent primary insulation panels to the support wall.

The seal washer can be secured to the secondary sealing membrane in various ways. In one embodiment, a seal washer or collar is hermetically welded onto the secondary sealing membrane.

In one embodiment, the deformable sealing portion is deformable through the thickness of the tank wall such that the seal washer can slide along the stem through the thickness of the tank wall.

In one embodiment, the lateral dimension of the central opening of the seal washer is greater than the lateral dimension of the portion of the stem that engages within the central opening, such that the stem is positioned within the central opening of the seal washer against the tank wall. It is configured to be movable in a direction perpendicular to the thickness direction. Such a seal washer allows the seal washer to move freely relative to the stem in a direction perpendicular to the thickness of the tank wall. More specifically, the primary anchor member is attached to the stem to provide a sealing connection between the sealing washer and the secondary sealing membrane relative to the bearing element interacting with the primary insulation panel or panels. allow movement. Therefore, any movement of the secondary insulation panel and/or the primary insulation panel in the plane perpendicular to the thickness direction of the tank wall by using the primary anchoring member is not transmitted to the secondary sealing membrane, thus resulting in different shrinkage. , the stresses associated with deformation of the support wall or movement of the liquid in the tank are reduced and the risk of damage to the sealing connection between the secondary sealing membrane or the sealing washer and the secondary sealing membrane is limited.

In one embodiment the primary anchor member further comprises a stopper provided on the stem, the stopper being arranged on the stem between the bearing element and the seal washer, the stopper having a stop surface facing the seal washer, is configured to prevent the seal washer from moving relative to the stem through the thickness of the tank wall toward the primary sealing membrane.

Due to this feature, the deformation of the secondary sealing membrane in the thickness direction of the tank wall is limited at the sealing connection between the sealing washer and the opening of the secondary sealing membrane. In particular, it prevents deformation of the secondary sealing membrane in the thickness direction of the tank wall in the event of excessive pressure in the secondary insulating barrier or deformation of the secondary insulating barrier. Specifically, since the seal washer is sealingly secured to the secondary sealing membrane around the opening in the secondary sealing membrane, for forces tending to move the secondary sealing membrane towards the interior of the tank, A local deformation of the secondary sealing membrane at the sealing connection with the sealing washer is prevented by the sealing washer abutting the stop surface. Therefore, the risk of damage to the secondary sealing membrane, for example by perforation, is reduced. Furthermore, this local deformation limitation of the secondary sealing membrane makes it possible to limit the risk of damage to the deformable seal.

In one embodiment, the stem comprises a shoulder projecting laterally from the stem beyond the central opening of the seal washer such that the outer surface of the shoulder forms the stop surface. Such a stopper is simple to manufacture and does not require additional parts.

In one embodiment, the primary anchor member further comprises a bell portion attached to the stem, the bell portion comprising a mounting portion and a protector, the mounting portion having a central passageway through which the stem passes, the protector sealing from the mounting portion. Extending through the thickness of the tank wall toward the collar of the washer, the protector is hollow and the deformable seal is housed within the protector. Such a bell surrounding the stem of the primary anchor member can protect the stem and deformable seal.

In one embodiment, the mounting portion of the bell comprises a plateau extending in a plane perpendicular to the thickness of the tank wall, the plateau comprising a passageway through the bell.

In one embodiment, the deformable seal portion is entirely contained within the protective portion of the bell portion. Thus, the deformable seal portion is protected by the bell portion during attachment of the primary anchor member to the tank, for example. In one embodiment, the deformable seal portion is secured to the stem between the passageway of the mounting portion of the bell portion and the seal washer.

In one embodiment, the end of the protective portion of the bell portion opposite the mounting portion is provided with a radially outwardly extending lip, the outer surface of the lip forming a stop surface by which the sealing washer is secured against the tank wall. It is configured to prevent movement in the thickness direction.

In one embodiment, the outer end of the protective portion opposite the mounting portion defines a stop surface facing the seal washer, thereby preventing the seal washer from moving through the thickness of the tank wall. It is

In one embodiment, the bell portion is fixed to the stem. The stop surface is thus formed by a guard in a fixed position relative to the stem, thereby preventing movement of the seal washer relative to the stem. In one embodiment, the attachment portion of the bell portion is welded to the stem.

In one embodiment, the deformable sealing portion comprises a deformable bellows portion, the deformable bellows portion being hollow, extending around the stem along an axial direction of the stem, and extending at a first portion of the bellows portion. The axial end is sealingly secured to the stem and the second axial end of the bellows portion is sealingly secured to the seal washer. Such a deformable seal in the form of a bellows is simple to manufacture and allows sufficient sealing deformation of the deformable seal. Such bellows can be made from many materials. In one embodiment, the bellows are made from stainless steel. Such stainless steel bellows are thin enough to allow elastic deformation. In one embodiment, the bellows is made of stainless steel with a thickness of 0.1 mm to 0.5 mm, such as 0.1 mm to 0.3 mm.

In one embodiment, the accordion has a plurality of pleats of equal or increasing diameter, such that the central portion of the accordion formed by the plurality of pleats has substantially the shape of a column of revolution.

In one embodiment, the bellows has at least 3, preferably 3 to 32, ideally 6 to 24 pleats or corrugations.

In one embodiment, the bellows has a flared shape and the circumference of the second axial end of the bellows secured to the seal washer is the same as the first axial end of the bellows secured to the stem. greater than the perimeter of

In one embodiment, the accordion has a plurality of pleats that increase in diameter from the end secured to the stem to the end secured to the seal washer. Accordingly, the portion of the bellows formed by the plurality of pleats has a conical shape, the conical shape having its greatest diameter at the location of the end fixed to the seal washer.

In one embodiment, the seal washer has an inner surface extending in a plane perpendicular to the thickness of the tank wall. In one embodiment, the inner surface is arranged opposite a stop surface to interact with a stop surface forming, for example, of the bell or forming part of the stem, whereby the seal washer is positioned against the stem of the tank. It is configured to prevent movement in the thickness direction.

In one embodiment, the deformable seal portion is secured to the inner surface of the seal washer at a radially outer portion of the inner surface of the seal washer.

In one embodiment, the seal washer comprises ribs projecting from the inner surface of the seal washer, and the deformable seal portion is sealingly secured to the ribs. In one embodiment, the ribs of the seal washer extend from a radially inner portion of the inner surface of the seal washer.

In one embodiment, the tank includes a plurality of secondary anchor members, each secondary anchor member configured to be secured to the support wall and a secondary insulation when the secondary anchor member is secured to the support wall. configured to interact with the secondary insulating barrier to support the barrier toward the support wall;

In one embodiment, the base of the primary anchor member is secured to the secondary anchor member.

In one embodiment, the base of the primary anchor member is rigidly secured to the secondary insulation barrier. In this case, the primary anchor member is held to the support wall by the secondary insulation barrier.

In one embodiment, the secondary insulation barrier comprises a plurality of juxtaposed secondary insulation panels. In one embodiment, the one or more secondary insulation panels comprise a bottom plate, a cover plate, and an insulation lining interposed between the bottom plate and the cover plate, the secondary sealing membrane opposite the insulation lining. is placed on the inner surface of the cover plate of the In one embodiment, the one or more secondary insulation panels comprises an intermediate plate interposed between the cover plate and the bottom plate of the secondary insulation panel, and the insulation lining of the secondary insulation panel comprises the bottom plate and the bottom plate. An outer insulating lining inserted between the intermediate plate and an inner insulating lining inserted between the intermediate plate and the cover plate.

In one embodiment, the secondary insulation barrier comprises an anchor plate and the base of the primary anchor member is secured to the anchor plate. In one embodiment, the anchor plate is received in a recess formed in the cover plate of the secondary insulation panel, the anchor plate having an inner surface that is flush with the inner surface of the cover plate.

In one embodiment, the anchor plate comprises a threaded opening, the base has an outer threaded end, and the base of the primary anchor member connects the threaded end of the base to the threaded opening of the anchor plate. It is fixed to the anchor plate by screwing.

In one embodiment, the inner end of the stem opposite the base is threaded, the primary anchor member comprises a nut screwed onto the inner threaded end, and the bearing element comprises the nut and the primary anchor member. is inserted between the base of

In one embodiment, the deformable seal portion is interposed between the bearing element and the seal washer.

In one embodiment, one or more elastic washers are inserted between the nut and the bearing element.

In one embodiment, the primary anchor member has an anchor shoulder portion projecting laterally from the stem, the anchor shoulder portion forming an anchor surface extending in a plane perpendicular to said thickness direction, the anchor surface being the bearing surface. Opposing the element, a deformable seal portion is sealingly secured to the anchor surface.

In one embodiment, the inner end of the deformable seal secured to the stem is inserted between the mounting portion of the bell portion and the flat anchoring surface of the anchor shoulder portion.

In one embodiment, the bell is free to move through the thickness of the tank wall. In one embodiment, the freedom of movement of the bell is limited on one side by a nut or elastic washer or washers, if desired, attached to the stem and on the other side by the anchoring surface of the anchoring shoulder. be done.

In one embodiment, the inner axial end of the deformable seal fixed to the stem is inserted between the anchoring surface of the anchoring shoulder and a nut or optionally a resilient washer attached to the stem. .

In one embodiment, the secondary sealing membrane and/or the primary sealing membrane are made from an alloy of iron and nickel, for example with a typical expansion of 1.2×10 ⁻⁶ K ⁻¹ to 2×10 ⁻⁶ K ⁻¹ . It is an alloy with modulus. In one embodiment, the secondary sealing membrane and/or the primary sealing membrane are made from an alloy of iron and manganese, eg, typically with an expansion of about 7×10 ⁻⁶ K ⁻¹ to about 9×10 ⁻⁶ K ⁻¹ . It is made from an alloy of iron and manganese with a modulus. The secondary sealing membrane and/or the primary sealing membrane comprise a plurality of strakes having raised edges that are juxtaposed and welded in pairs via the raised edges.

In one embodiment, the primary sealing membrane and/or the secondary sealing membrane comprise a plurality of preferably rectangular metal plates welded together. In one embodiment, the primary sealing membrane and/or the secondary sealing membrane comprise a first series of parallel corrugations extending in a first direction and a second series of parallel corrugations extending in a second direction. and the first direction and the second direction secantes each other.

In one embodiment, the transfer wedge is positioned around the bell in the gap between the bell and the adjacent primary insulation panel, for example between the bell and the bottom plate of the adjacent primary insulation panel. With these features, lateral movement of the insulation panel interacting with the anchor member is transmitted through the transmission wedge to the bell portion, stem, and stem support, e.g., secondary insulation barrier, thereby providing a sealing washer and It is possible to absorb the lateral forces exerted by the primary insulation panel without the risk of damaging the sealing connection between it and the sealing membrane.

In one embodiment, the transfer wedge has a thickness, considered in the thickness direction of the tank wall, less than the thickness of the bottom plate of the primary insulation panel. Therefore, only the bottom plate abuts the transfer wedge when the primary insulation panel moves laterally, ensuring good transmission of forces between the primary insulation panel and the transfer wedge.

In one embodiment, the transfer wedge includes an outer portion and a plateau portion, the outer portion extending through the thickness of the tank wall around the seal washer, the plateau portion having a central opening surrounding the bell portion, the outer portion The and plateau portions form a housing in which the seal washer is received with clearance so that the wedge can transmit lateral force to the bell portion without interfering with the seal washer.

In one embodiment, the transfer wedge further comprises an inner portion extending from the plateau portion and surrounding the bell portion.

In one embodiment, the outer portion of the transfer wedge is cylindrical. In one embodiment, this outer portion is coaxial with the stem.

In one embodiment, the transfer wedge comprises wings, preferably a plurality of wings, parallel to the thickness of the tank wall, extending radially from the outer portion of the transfer wedge. In one embodiment, the one or more wings are housed between two adjacent primary insulation panels.

In one embodiment, the transfer wedge is smaller than the space left between the panels. Therefore, mounting the wedge between the panels is facilitated.

In one embodiment, the seal washer includes flats and the bell includes flats that twist into a deformable seal when the anchor member is screwed into its support, e.g., the secondary insulation barrier. It is configured to be gripped by the fasteners so that the stem and seal washer rotate together without causing a strain. In one embodiment, the seal washer includes flats and the stem includes flats that are configured such that the stem and seal washer rotate together without twisting the deformable seal. It is configured to be gripped by a fastener.

Said tanks may for example form part of an onshore storage facility for storing LNG or may be used in coastal or deep sea floating structures, in particular LNG carriers, floating storage and regasification units (FSRUs), It can be installed in a remote floating production and storage unit (FPSO) or the like. Such tanks can also be used as fuel tanks in any type of carrier.

In one embodiment, the present invention also provides a carrier for transporting cryogenic liquid products comprising a double hull and a tank as described above located within the double hull.

In one embodiment, the present invention also provides a method for loading and unloading a carrier vessel as described above, the method comprising: from a floating or land storage facility to a tank of the carrier vessel or from a tank of the carrier vessel to a floating or land storage facility; It involves sending the cryogenic liquid product through an insulated pipeline to the facility.

In one embodiment, the present invention also provides a transport system for transporting a cryogenic liquid product, the system connecting a carrier vessel as described above and a tank located within the hull of the carrier vessel to a floating or land storage facility. a pump for effecting flow of the cryogenic liquid product through the insulated pipeline from the floating or onshore storage facility to the tanks of the carrier vessel or from the tanks of the carrier to the floating or onshore storage facility; Prepare.

The present invention will be better understood in the following description of some specific embodiments thereof, given by way of non-limiting illustration only, with reference to the accompanying drawings, and other objects, details, features, and the advantages will become clearer.

FIG. 2 is a partial cut-away view from above of the wall of the closed and insulated tank, without the primary sealing membrane shown; 2 is a cross-sectional view of the tank wall of FIG. 1 through section AA shown in FIG. 1; FIG. 3 is a detailed view of area B of FIG. 2 showing primary anchor members securing two adjacent primary insulation panels; FIG. Figure 4 is a schematic perspective view of the anchor member of Figure 3; Figure 5 is a schematic perspective view of the primary anchor member shown in Figure 4, without the bell portion shown; FIG. 4 is a cross-sectional view of a primary anchor member according to a second embodiment; FIG. 10 is a cross-sectional view of a primary anchor member according to a third embodiment; FIG. 11 is a cross-sectional view of a primary anchor member according to a fourth embodiment; 1 schematically shows, in cutaway, a tank of an LNG carrier and a terminal for loading and unloading this tank; FIG. FIG. 11 is a schematic perspective view of a primary anchor member according to a fifth embodiment; 11 is a cross-sectional view of the primary anchor member of FIG. 10 interacting with two primary insulation panels; FIG. Figure 12 is a schematic perspective view of the anchor member of Figure 11; FIG. 11 is a cross-sectional view of a primary anchor member according to a sixth embodiment, the primary anchor member comprising a transmission wedge; Figure 14 is a top view of the primary anchor member of Figure 13; FIG. 4 is a schematic perspective view also including a cross-section through a portion of a secondary insulation barrier on which a portion of the secondary sealing membrane rests, the secondary insulation barrier comprising an anchor plate configured to receive the primary anchor member; . 16 is a schematic perspective view of a portion of a primary anchor member and a tool for attaching this portion of the primary anchor member to the anchor plate of the secondary insulation barrier of FIG. 15; FIG. 17 is a schematic perspective view including a section through the primary anchor member of FIG. 16 after the secondary insulating barrier has been attached to the anchor plate and a bell portion has been added; FIG.

In the remainder of this specification, the terms "outer" and "inner" are used to indicate the relative position of another element with respect to the interior of the tank according to the definitions given herein. Elements near or facing the interior of the tank are therefore described as inner elements, as opposed to outer elements located near or facing the exterior of the tank. Similarly, the expression "radially at the edge" or "radially outward" means a portion at a distance from the axis defining the circular element, and "radially inward" means a portion close to this axis. is the opposite of the expression of Furthermore, the expression "transverse" is used to describe the direction of movement or extension of an element in a direction in the plane perpendicular to the thickness direction of the tank wall.

A closed and insulated tank for storing a liquefied fluid such as liquefied natural gas (LNG) comprises a plurality of tank walls having a multilayer structure. Figures 1 and 2 show part of such a wall of a closed and insulated tank. In these FIGS. 1 and 2, the walls of the tank are continuous in the thickness direction from the outside of the tank to the inside, a secondary insulation barrier (hereinafter, secondary insulation) held on a support wall (not shown) a barrier 1), a secondary sealing membrane 2 placed on the secondary insulating barrier 1, a primary insulating barrier (hereinafter referred to as primary insulating barrier 3) placed on the secondary sealing membrane 2, and a a primary sealing membrane 4 configured to be in contact with liquefied natural gas. The support structure may in particular be formed by the hull or double hull of the carrier. The support structure comprises a plurality of support walls defining the general shape of the tank, which is usually polyhedral, each tank wall being fixed on a respective support wall.

The secondary insulation barrier 1 comprises a plurality of secondary insulation panels 5 secured on the support wall by secondary anchor members (not shown). The secondary insulation panels 5 are generally parallelepiped shaped and arranged in parallel rows. A bead of mastic (not shown) is laid between the secondary insulation panel 5 and the support wall to form a gap between the support wall and a flat reference surface. Kraft paper can be inserted between the beads of mastic and the support wall to prevent the beads of mastic from adhering to the support wall. Alternatively, the secondary insulation panel 5 is secured by adhesion to the support wall by placing beads of mastic in direct contact with the support wall.

The structure of the secondary insulation panel 5 shown in FIG. The bottom plate 7 and the cover plate 8 are made of plywood, for example. The insulating lining 9 is for example a layer of insulating polymer foam sandwiched between the bottom plate 7 and the cover plate 8 . An insulating lining 9 is adhesively bonded to the bottom plate 7 and the cover plate 8 . The insulating polymer foam may in particular be a polyurethane-based foam, optionally reinforced with fibres.

The secondary insulation panel 5 comprises recesses for receiving secondary anchor members. Such recesses are for example formed in the insulating lining 9 and the cover plate 8 so as to expose the corners of the bottom plate 7 . The secondary anchor member comprises a base fixed on the support wall and a stem extending through the thickness of the tank wall. The base is for example hollow, with an opening through which the stem passes, and a nut is screwed onto the end of the stem, which is housed in the hollow base, to keep the stem fixed to the base and thus to the support wall. In another embodiment, the secondary anchor member may take the form of a stem welded to the inner hull.

In one embodiment, the recesses are arranged in the corner zones. The corners of the bottom plate 7 have notches to allow passage of the stems of the secondary anchor members. A secondary bearing plate is engaged with the stem and retained thereon by a nut threaded into the inner end of the stem opposite the base. This secondary bearing plate supports (compresses) the corners of the bottom plates 7 of adjacent secondary insulation panels 5, such as four adjacent secondary insulation panels 5, to support these panels 5 to the support walls. configured to be fixed. In one alternative, the secondary bearing plate may support the secondary insulation panel 5 via batten bearings supporting the corners of the bottom plate 7 .

In another alternative, the recesses are located on two sides of the secondary insulation panel 5 and the secondary anchor members are located on two adjacent secondary insulation panels 5 in the width or length direction of the secondary insulation panel 5 . is placed in the above-mentioned recess between

The cover plate 8 is provided with grooves for receiving the weld supports 6 on its inner surface, i.e. the surface facing away from the insulating lining 9 .

An example of the construction of the secondary insulation panel 5 and the secondary anchor member has been described above. Therefore, in another embodiment the secondary insulation panel 5 may have another general construction, such as that described in WO2012/127141. In this case, the secondary insulation panel 7 extends in the thickness direction of the tank wall between the bottom plate, the cover plate and between the bottom plate and the cover plate, with an insulating lining such as perlite, glass wool or rock wool. and supporting webs defining a plurality of filled compartments.

In another embodiment, the secondary insulation panel comprises a bottom plate, a cover plate and an intermediate plate interposed between the bottom plate and the cover plate. The insulating lining comprises a first layer of insulating lining interposed between the bottom plate and the intermediate plate and a second layer of insulating lining interposed between the intermediate plate and the cover plate. A first layer of insulating lining is for example adhesively bonded to the bottom plate and the intermediate plate. A second layer of insulating lining is for example adhesively bonded to the intermediate plate and the cover plate. In this embodiment, the recess may be formed only in the cover plate and the second layer of insulating lining, with the secondary bearing plate supporting the exposed portion of the intermediate plate. Additionally, notches for passage of stems are formed in the intermediate plate, the first layer of insulating lining and the bottom plate. Such secondary insulation panels are described for example in WO2014/096600.

In one embodiment, the secondary insulation panel is adhesively bonded to the support wall, for example by beads of mastic as described above. In this case, it is possible to omit the secondary anchor members and the recesses for receiving them.

Returning to FIG. 1, it can be seen that the secondary sealing membrane 2 comprises a continuous layer of metallic strakes 10 with raised edges. The strakes 10 are welded by raised edges on parallel weld supports 6 fixed in grooves formed in the cover plate 8 of the secondary insulation panel 5 . The strake 10 is an iron-nickel alloy, for example made of Invar®, which typically has a coefficient of expansion of 1.2×10 ⁻⁶ K ⁻¹ to 2×10 ⁻⁶ K ⁻¹ . Also, alloys of iron and manganese, typically having coefficients of expansion of about 7×10 ⁻⁶ K ⁻¹ to about 9×10 ⁻⁶ K ⁻¹ can be used.

The primary insulation barrier 5 comprises a plurality of primary insulation panels 11 secured on the support wall by primary anchor members 12, described below. The primary insulation panels 11 have a generally parallelepiped shape and are juxtaposed to form the primary insulation barrier 3 . Furthermore, their width, length or thickness dimensions may be the same as or different from the dimensions of the secondary insulation panel 5 . In particular, the thickness of these tank walls in the thickness direction may be less than the thickness of the secondary insulation panels 5 . The primary insulation panels 11 are each offset with respect to the secondary insulation panels 5 on which they rest. Adjacent corners of the primary insulation panel 11 are thus grouped along the cover plate 8 of the secondary insulation panel 5 on which the primary insulation panel 11 rests.

The primary insulation panel 11 can have a multilayer structure similar to the construction of the secondary insulation panel 5 . In the example shown, the primary insulation panel 11 thus comprises, in order along the thickness of the tank wall, a bottom plate 13, for example of plywood, a primary insulation lining 14, and a cover plate 15, for example of plywood. The primary insulating lining is, for example, a layer of insulating polymer foam, eg polyurethane-based foam, optionally reinforced with fibres. The insulating lining 14 is preferably adhesively bonded to the bottom plate 13 and the cover plate 15 .

The primary insulation panel 11 is provided with recesses in its corner zones so that the bottom plate 13 protrudes relative to the primary insulation lining 14 and the cover plate 15 . The bottom plate 13 thus forms bearing zones configured to interact with the primary bearing plates 16 of the primary anchor members 12 in the corner zones of the primary insulation panel 11 . In the embodiment shown in FIG. 3, a wedge 17 has been added to the bottom plate 13, which has a shape similar to that of the bearing zone and which is attached to the primary bearing plate 16 to secure the primary insulation panel 11. interact.

The bottom plate 13 of the primary insulation panel 11 is provided with grooves 18 for receiving the raised edges of the strakes 10 of the secondary sealing membrane 2 . The cover plate 15 includes anchor strips 19 for securing the primary sealing membrane 4 shown in FIG. These anchor strips 19 are accommodated in counterbores formed in the inner surface of the cover plate 15 . The primary insulation panel 11 may further comprise relief slots 20 formed in inner portions of the cover plate 15 and the primary insulation lining 14 . Such relief slots 20 have the purpose of preventing deformation or damage to the primary insulation panel 11 caused by differential shrinkage between the cover plate 15 and the primary insulation lining 14 . Such relief slots 20 also allow the corrugations 21 to flex, thus stressing the primary sealing membrane 4 and the primary insulating barrier 3 in the case of primary sealing membranes 4 with corrugations 21 as described below. to prevent

An example of the structure of the primary insulation panel 11 has been described above. Thus, in other embodiments the primary insulation panel 11 may have another general construction, such as that described in WO2012/127141.

In another embodiment, the primary insulation barrier 3 comprises primary insulation panels having at least two different types of construction, for example the two constructions described above, depending on where they are mounted in the tank.

The primary sealing membrane 4 comprises a continuous layer of rectangular metal sheets with two series of corrugations 21 perpendicular to each other. As is known, rectangular metal sheets are welded together to form small overlapping areas along their edges. The rectangular metal sheets preferably have dimensions in terms of width and length equal to integer multiples of the spacing between the corrugations and equal to integer multiples of the dimensions of the primary insulation panel 11 .

Primary anchor member 12 is described below with reference to Figures 3-5. FIG. 3 shows a detailed view of the primary anchor member 12 indicated with the reference character B in FIG. Nut 32 and bearing plate 16 are not shown in FIGS. A single primary anchor member 12 is shown in FIGS. 3-5 and the following description of this anchor member is the same for one, some or all of the primary anchor members 12 incorporated into the closed insulated tank. Applies to

As described above, in the embodiment shown in FIGS. 1-5 the primary insulation panel 11 is secured to the support wall by the secondary insulation panel 5 . For this purpose, the cover plate 8 of the secondary insulation panel 5 is provided with anchor plates 22 . This anchor plate 22 is housed in a recess 23 formed in the cover plate 8 .

Recess 23 has an inner portion 24 with a first diameter and an outer portion 25 with a second diameter. The second diameter is larger than the first diameter such that the outer portion 25 of the recess 23 is a transverse reinforcement inserted between a portion of the cover plate 8 surrounding the inner portion 24 and the insulating lining 9. configured to form a timber.

Anchor plate 22 has a shape complementary to recess 23 . The inner surface 26 of the anchor plate 22 is flush with the inner surface 27 of the cover plate 8 of the secondary insulation panel 5 . The anchor plate 22 thus forms together with the cover plate 8 a substantially continuous flat surface on which the secondary sealing membrane 2 rests. Also, the outer part 28 of the anchor plate 22 is received in the outer part 25 of the recess 23 and thus inserted between the cover plate 8 and the insulating lining 9 . The anchor plate 22 is preferably adhesively bonded to the insulating lining 9 of the secondary insulating panel. This prevents movement of the anchor plate 22 in the thickness direction of the tank wall. This anchor plate 22 further comprises a threaded central housing 29 .

Primary anchor member 12 comprises base 30 , stem 31 , primary bearing plate 16 and nut 32 .

The base 30 has external threads and screws onto the central housing 29 of the anchor plate 22 . In other words, base 30 of primary anchor member 12 is secured to anchor plate 22 .

A stem 31 extends from the base 30 through the thickness of the tank wall toward the interior of the tank. Stem 31 passes through an opening formed in secondary sealing membrane 2 . As shown in FIGS. 1-3, this stem 31 extends into the space separating the corners of the two primary insulation panels 11 .

Primary bearing plate 16 has a central passageway 60 . This primary bearing plate 16 engages the stem 31 . The primary bearing plate 16 supports a wedge 17 positioned on the projecting portion of the bottom plate 13 of the primary insulation panel 11 with which the primary anchor member 12 interacts. Additionally, the inner end of stem 31 opposite base 30 is threaded and a nut 32 is screwed onto this inner end of stem 31 to press primary bearing plate 16 against wedge 17 . In the embodiment shown in FIG. 3, a resilient washer 33 , eg a Belleville washer, is inserted between the primary bearing plate 16 and the nut 32 .

The primary anchoring member 12 further comprises a sealing washer 34 to ensure the sealing of the secondary sealing membrane 2 at the opening in the secondary sealing membrane 2 through which the stem 31 passes.

This sealing washer 34 comprises an annular body 35 with a central opening 36 . Seal washer 34 further comprises a collar 37 extending radially outwardly from an outer portion of the radially outer surface of annular body 35 . The inner surface 38 of the annular body 35 is also provided with ribs 39 projecting in the thickness direction of the tank wall. This rib 39 extends from a radially inner portion of the inner surface 38 . Collar 37 is formed, for example, by the peripheral edge of annular body 35 .

Seal washer 34 engages stem 31 through central opening 36 of seal washer 34 . A seal washer 34 is inserted between the secondary sealing membrane 2 and the primary bearing plate 16 . The diameter of central opening 36 in seal washer 34 is greater than the diameter of the portion of stem 31 passing through central opening 36 . Therefore, a lateral clearance, ie a clearance perpendicular to the thickness of the tank wall, separates the stem 31 from the radially inner surface defining the central opening 36 of the annular body 35 . This clearance allows lateral movement of seal washer 34 relative to stem 31 and thus relative to primary bearing plate 16 .

In an embodiment not shown, the central opening is not circular and has at least one lateral dimension greater than said at least one lateral dimension of the stem 31 . Thus, in such an embodiment, said at least one lateral clearance separates the central opening 36 from the stem and allows the seal washer to move in said at least one lateral direction relative to the stem 31 .

A collar 37 is sealingly secured to the secondary sealing membrane 2 around the opening of the secondary sealing membrane 2 . This is achieved, for example, by welding.

Primary anchor member 12 includes an anchor shoulder 40 projecting radially outwardly from stem 31 . This anchor shoulder 40 is interposed between the seal washer 34 and the primary bearing plate 16 . The anchor shoulder 40 has a flat anchor surface 41 extending in a plane perpendicular to the thickness of the tank wall. This anchor surface 41 faces the interior of the tank.

Primary anchor member 12 comprises a deformable seal that sealingly connects stem 31 and seal washer 34 . The deformable seal portion comprises a bellows portion 42 . The inner axial end of this bellows 42 is hermetically fixed to the stem 31 . The outer axial ends of the bellows 42 are sealingly secured to the seal washer 34 . More specifically, the inner axial end of the bellows portion 42 is sealingly secured to the anchoring surface 41 of the anchoring shoulder portion 40 . The outer axial ends of bellows 42 are sealingly secured to ribs 39 projecting from inner surface 38 of annular body 35 . The inner axial end of the bellows 42 is welded to the stem 31, for example. The outer axial ends of bellows 42 are welded to seal washer 34, for example.

The bellows 42 has deformable pleats 61, which in the embodiment shown in FIG. 3 are three. In an embodiment not shown, the number of pleats 61 in accordion portion 42 is not limited to three, but may be greater depending on the space between shoulder portion 40 and surface 38 of collar 37 . The bellows 42 can thus have 3 to 32 folds 61, ideally 6 folds 61 to 24 folds 61, depending on said space, said space being for example 20 mm to 45 mm. . The bellows portion 42 is generally cylindrical. The pleats 61 forming the bellows 42 have the same dimensions. Such a bellows portion 42 is made of stainless steel, for example. The thickness of the bellows 42 is small, preferably less than 1 mm, for example 0.1 mm to 0.5 mm, more particularly 0.1 mm to 0.3 mm, to ensure that the bellows 42 is flexible. be.

This bellows 42 forms a flexible, deformable sealing connection between the stem 31 and the sealing washer 34 . This flexible, deformable connection in combination with the clearance between the seal washer 34 and the stem 31 permits sealing relative movement between the seal washer 34 and the stem 31 . Thus, the seal washer 34 is sealingly secured to the secondary sealing membrane 2 and the stem 31 supports the primary insulation panel 11 together with the primary bearing plate 16 so that damage to the secondary sealing membrane 2 or damage to the secondary sealing membrane 2 occurs. Relative movement between the secondary sealing membrane 2 and the secondary insulation panel 5 and/or the primary insulation panel 11 is possible without the risk of loss of tightness. In particular, when the stems 31 are fixed to the secondary insulation panel, any deformation and/or movement of the secondary insulation panel 5 may, by this deformation and/or movement, affect the secondary sealing membrane 2 or the sealing washer 34 and the secondary sealing. This is possible without stressing the connection between the membrane 2 .

Such relative movement between the secondary insulation panel 5 and/or the primary insulation panel 11 and the secondary sealing membrane 2 may result in differential shrinkage, deformation of the secondary insulation barrier 1 and/or deformation of the support wall, or It may result from stress on the primary insulation panel 11 due to liquid movement within the tank.

On the one hand, this primary anchor member is provided with a bell portion 43 in order to protect the bellows portion 42 during, for example, construction of the tank and installation of the primary anchor member 12 . The bell portion 43 has an attachment portion 44 and a protection portion 45 . This bell portion 43 can be combined with various types of bellows portions 42 described above and below.

Mounting portion 44 has a flat shape and a central opening. A bell portion 43 is attached to the stem 31 of the primary anchor member 12 and the stem passes through a central opening in the mounting portion 44 . The mounting portion is inserted between the anchor shoulder portion 40 and the primary bearing plate 16 . The bell is therefore prevented from moving in the thickness direction of the tank wall by the primary bearing plate 16 on one side and by the anchoring surface 41 on the other side.

Protective portion 45 is hollow and has an inner end adjacent the periphery of mounting portion 44 . The protective portion 45 extends from its inner end along the bellows portion 42 toward the seal washer 34 , and the bellows portion 42 is housed in the hollow protective portion 45 . The protector 45 is also flared so that the outer edge of the protector 45 is aligned with the collar 37 of the seal washer 34 . Bell portion 43 thus generally surrounds bellows 42 from the inner end of bellows 42 on anchor surface 41 to the outer end of bellows 42 secured to rib 39 .

The outer end of the protection 45 has a lip 46 extending in a plane perpendicular to the thickness of the tank wall. This lip 46 forms a stop surface 47 arranged opposite the collar 37 . Such a stop surface 47 prevents movement of the collar 37 and thus of the seal washer 34 towards the interior of the tank, and the bell portion 42 itself is prevented from moving by its mounting portion 44 abutting against the primary bearing plate 16. .

Collar 37 is therefore sealingly secured to secondary sealing membrane 2 so that in the event of deformation of the support wall or excessive pressure on secondary sealing membrane 2, the secondary sealing membrane 2 at primary anchoring member 12 is prevented from Local deformation is prevented by the abutment of the collar 37 of the seal washer 34 against the stop surface 47 . In another embodiment, the mounting portion 44 of the bell portion 43 is secured to the stem, for example by welding.

In an embodiment not shown, the primary insulation panel 11 and the secondary insulation panel 5 have the same dimensions such that the corners of the secondary insulation panel 5 align with the corners of the primary insulation panel 11 in the thickness direction of the tank wall. are placed in In such embodiments, the primary anchor members 12 are secured directly to the secondary anchor members rather than to the secondary insulation panel 5 . Such an arrangement is described, for example, in WO2014096600, which discloses a joint anchoring device for a secondary insulation panel 5 and a primary insulation panel 11, wherein the base 30 of the primary anchor member 12 is fixed to one end of the secondary anchor member. be. Thus, in this embodiment, in the primary anchor member as described above, the base 30 of the primary anchor member 12 is located inside the secondary anchor member rather than the anchor plate 22 housed within the cover plate 8 of the secondary insulation panel 5. It is fixed to the base plate which is fixed at the end.

Figure 6 shows a primary anchor member 12 according to a second embodiment. Elements that are the same as or that perform the same function as those described above with reference to Figures 1 to 5 are labeled with the same reference numerals.

This second embodiment differs from the embodiment shown in FIGS. 1 to 5 in that the annular body of the sealing washer is chamfered, i.e. has a radially outer surface inclined with respect to the thickness direction of the tank wall. .

Figure 7 shows a primary anchor member 12 according to a third embodiment. Elements that are the same as or that perform the same function as those described above with reference to Figures 1 to 5 are labeled with the same reference numerals.

This third embodiment differs from that shown in FIGS. 1-5 in that the bellows 42 is flared. Accordingly, the pleats 61 forming the bellows 42 increase from the inner axial end of the bellows 42 secured to the anchor surface 41 to the outer axial end of the bellows 42 secured to the seal washer 34 . have dimensions.

Furthermore, in this third embodiment, the inner surface 38 of the annular body 35 of the sealing washer 34 does not include ribs 39 and the inner surface 38 is flat. In a third embodiment, the outer axial ends of bellows 42 are directly secured to flat inner surface 38 . In particular, the accordion portion 42 has a flared shape so that the outer axial end of the accordion portion 42 is secured to the radially outer periphery of the inner surface 38 .

The third embodiment also differs from the embodiment described with reference to FIGS. 1-5 in that the primary anchor member 12 does not include a bell portion 43 . However, it is also possible to add such a bell portion 43 .

In this third embodiment, the stem 31 has a laterally projecting shoulder 48 . This shoulder 48 is inserted between the anchor shoulder 40 and the seal washer 34 . Moreover, the shoulder 48 has at least one lateral dimension greater than the dimension of the central opening of the seal washer 34 . This shoulder 48 thus has an outer surface 49 facing the inner surface 38 of the annular body 35 of the sealing washer 34 . In other words, the periphery of this outer surface 49 forms the stop surface 47 . This shoulder 48 therefore acts as a stop for the sealing washer 34 and prevents the sealing washer 34 from moving towards the interior of the tank and prevents local deformation of the secondary sealing membrane 2 .

Figure 8 shows a primary anchor member 12 according to a fourth embodiment. Elements that are the same as or that perform the same function as those described above with reference to Figures 1 to 5 are labeled with the same reference numerals.

In this fourth embodiment the primary anchor plate 16 is replaced by an anchor cross 54 . This anchor cross 54 has a mounting portion 55 and a plurality of bearing legs 56, for example four bearing legs 56, as shown in FIGS. 7 and 8 of WO2014/057221.

The mounting portion 55 of the anchor cloth 54 is flat and extends in a plane perpendicular to the thickness direction of the tank wall. The attachment portion 55 has a central opening through which the stem 31 passes so that the anchor cross 54 is attached to the stem 31 .

Each bearing leg 56 has an inner end adjacent the periphery of mounting portion 55 . Each bearing leg 56 extends from mounting portion 55 to a bearing surface 57 formed by a projection of bottom plate 13 of primary insulation panel 11 . The outer end of the bearing leg 56 is provided with a lip 58 extending in a plane perpendicular to the thickness of the tank wall. This lip 58 supports the bearing surface 57 which retains the primary insulating panel 11 on the secondary sealing membrane 2 .

Such an anchor cross 54 provides some degree of protection for the bellows portion 42 in the same manner as the protective bell portion 43 described above with reference to FIGS.

In this fourth embodiment, the inner end of the bellows 42 is fixed to the side 59 of the anchor shoulder 40, for example in a recess formed in the outer part of the side 59 for this purpose.

Figures 10-12 show a primary anchor member 12 according to a fifth embodiment. In these figures, elements that are the same as or that perform the same function as those described above with reference to FIGS. 1 to 5 are labeled with the same reference numerals.

In this fifth embodiment, the protective portion 45 of the bell portion 43 is cylindrical and its generatrix is parallel to the thickness direction of the tank wall. The outer end of the protective portion 45 of the bell portion 43 is arranged to coincide with the inner surface 38 of the annular body 35 . In other words, the stop surface 47 formed by the lip 46 at the outer end of the protective portion 45 interacts with the inner surface 38 of the annular body 35 to prevent movement of the seal washer 34 into the tank interior. Collar 37 projects radially outwardly from annular body 35 beyond lip 46 . Furthermore, the inner axial end of the bellows 42 is hermetically fixed, for example by welding, to the outer surface of the anchor shoulder 40, ie the surface of the anchor shoulder 40 facing the seal washer 34. As shown in FIG.

When liquefied natural gas (LNG) is stored in tanks, the movement of this LNG within the tank, e.g. movement of the LNG associated with the movement of the carrier on which said tank is installed, causes lateral stresses on the primary insulation panel 11. may occur. Typically, movement of the LNG within the tank can exert lateral stress on the corrugations 21 of the primary sealing membrane 4 . This lateral stress in the corrugation 21 is transferred to the primary insulation panel 11 to which the primary sealing membrane 4 is fixed. Under the influence of this stress, the primary insulation panel 11 tends to move laterally, ie in the plane perpendicular to the thickness of the tank wall, thus tending to stress the primary anchor members 12 .

The collar 37 projects radially outwardly from the annular body 35 of the bell portion 43 beyond the lip 46 so that when the primary insulation panel 11 moves, the bottom plate 13 of the primary insulation panel 11 can abut the collar 37. . This abutment of the bottom plate 13 against the collar 37 causes significant stresses in the sealing connection between the collar 37 and the secondary sealing membrane 2 , stresses which compromise the integrity of the secondary sealing membrane 2 .

To prevent the sealing washer 34 from picking up forces due to lateral movement of the primary insulation panel 11, this fifth embodiment includes a transfer wedge 62. As shown in FIG. The transfer wedge 62 allows lateral forces to be transferred to the stem 31 and its support, eg the secondary insulating barrier. Also, the lateral dimensions of the wedges are smaller than the space between adjacent primary insulation panels, which allows sufficient mounting tolerances and allows forces to be transferred from the primary insulation panels to the stem 31 .

The transfer wedge 62 in this embodiment comprises a base 63 , a surrounding portion 64 and wings 65 .

The base 63 has a flat shape extending perpendicularly to the thickness direction of the tank wall. This base 63 is circular and coaxial with the stem 31 . Base 63 has a central opening 66 . This central opening 66 is circular and coaxial with the stem 31 . The dimensions of central opening 66 are greater than the dimensions of collar 37 such that base 63 is spaced a distance from collar 37 .

Base 63 rests on secondary sealing membrane 2 around collar 37 . The bottom plate 13 of the primary insulation panel 11 that interacts with the primary anchor members 12 may have an outer counterbore 67 to accommodate the base 63 .

Surrounding portion 64 comprises an outer skirt portion 68 and an inner skirt portion 69 connected by central plateau portion 82 .

The outer skirt portion 68 has a cylindrical wall with its generatrix parallel to the thickness of the tank wall. This outer skirt portion 68 extends from the inner periphery of the base 63 , ie from the edge of the central opening 66 of the base 63 . The outer skirt portion 68 extends in the thickness direction of the tank wall towards the interior of the tank over a thickness equal to or greater than the thickness of said thickness annulus 35 of the tank wall. Therefore, the inner end of the outer skirt portion 68 is radially aligned with the protective portion 45 of the bell portion 43 .

The central plateau portion 82 extends in a plane perpendicular to the thickness of the tank wall. The central plateau portion 82 extends radially inwardly from the inner end of the outer skirt portion 68 . The central plateau portion 82 has a central opening 83 with an inner diameter slightly larger than the outer diameter of the protective portion 45 of the bell portion. Central plateau portion 82 thus surrounds protective portion 45 of bell portion 43 .

The inner skirt 69 has a cylindrical wall with its generatrix parallel to the thickness of the tank wall. The inner skirt portion 69 extends from the inner circumference of the central plateau portion 82 , ie from the edge of the central plateau portion 82 that defines the central opening 83 . The inner skirt portion 69 extends towards the interior of the tank over a thickness less than the thickness of the protective portion 45 of the bell portion 43 . The inner skirt portion 69 thus surrounds the protective portion 45 of the bell portion 43 over only a portion of the thickness of the protective portion 45 .

Typically, the enclosure 64 surrounds the collar 37 to form a housing, seen in FIGS. 11 and 12, in which the collar 37 is received with clearance to protect the collar 37 .

Thus, when the primary insulation panel 11 is subjected to a stress that causes it to move laterally, the bottom plate 13 of this primary insulation panel 11 abuts the transfer wedge 62, typically the base 63 and/or the outer skirt. It abuts on portion 68 . Since the transfer wedge 62 surrounds the bell portion 43 and the distance the transfer wedge 62 is separated from the bell portion 43 is less than the distance the transfer wedge 62 is separated from the collar 37, the transfer wedge 62 exerts a large stress on the collar 37. contact with the bell portion 43 without generating a In other words, the force resulting from this lateral movement of the primary insulation panel 11 is transmitted through the bottom plate 13 of the primary insulation panel 11, which exerts a force on the transfer wedge 62, which in turn acts on the bell portion 43 and the stem 31. add force to The transmission wedges 62 thus ensure that forces resulting from lateral movement of the primary insulation panel 11 are not transmitted through the collar 37, resulting in a sealing connection between the collar 37 and secondary sealing membrane 2. Limit stress.

In the embodiment shown in FIGS. 10-12, the transfer wedge 62 further comprises four wing portions 65 that facilitate positioning of the transfer wedge 62 relative to adjacent primary insulation panels 11 . These positioning wings 65 are circumferentially distributed around the enclosure 64 at regular intervals. These wings 65 extend radially from the enclosure 64 parallel to the thickness of the tank wall. Each wing portion 65 is housed between two primary insulation panels 11 that interact with primary anchor members 12 . These wings 65 separate compartments that separate each of the primary insulation panels 11 .

In an embodiment not shown, the outer skirt portion 68 extends beyond the bottom plate 13 of the primary insulation panel 11 towards the interior of the tank. Thus, as the primary insulation panel 11 moves laterally, the insulation lining 14 also abuts the outer skirt portion 68 and is configured to transfer forces resulting from lateral movement of the primary insulation panel 11 to the transfer wedge 62 .

Figures 13 and 14 show a primary anchor member 12 according to a sixth embodiment.

This sixth embodiment differs from the fifth embodiment shown with reference to FIGS. 10 to 12 in that the outer edge of the protective portion 45 of the bell portion 43 is arranged to coincide with the collar 37. . Furthermore, a lip 46 at the outer end of the protective portion 45 projects radially beyond the collar 37 . This causes the stop surface 47 formed by the lip 46 at the outer end of the protective portion 45 to interact with the inner surface of the collar 37 to prevent movement of the seal washer 34 into the tank interior.

In this embodiment, transmission wedge 62 is formed by block 84 . This block 84 has a central opening. The inner diameter of this central opening is slightly larger than the outer diameter of the protective portion 45 of the bell portion 43 so that the block 84 surrounds the protective portion 45 of the bell portion 43 .

The thickness of the block 84 in the thickness direction of the tank wall is smaller than the thickness of the bottom plate 13 of the adjacent primary insulation panel 11, and the inner surface of the block 84 is outside the inner surface of the bottom plate 13 in the thickness direction of the tank wall. configured to be placed. Further, in the embodiment shown in FIG. 13, block 84 rests on the inner surface of lip 46 of protective portion 45 of bell portion 43 .

The outer peripheral side of block 84 has a shape generally complementary to the recess formed in bottom plate 13 of primary insulation panel 11 that interacts with primary anchor member 12 . In other words, the distance separating the bottom plate 13 of the primary insulation panel 11 from the block 84 substantially corresponds to the mounting clearance. Therefore, the lateral movement of the primary insulation panel 11 presses the outer peripheral side surface of the block 84 almost from the start of the movement.

Thus, when the primary insulation panel 11 is moved laterally, the bottom plate 13 of this primary insulation panel 11 abuts the transfer wedge 62, more specifically the outer peripheral side of the block 84, the transfer wedge substantially extending into the collar. It abuts the bell portion 43 and stem 31 without stressing 37 . In this way, the stresses that primary insulation panel 11 exerts on transmission wedge 62 are transmitted to stem 31 substantially bypassing the connection between collar 37 and secondary sealing membrane 2 .

One example of a method of attaching a primary anchor member is described below with reference to Figures 15-17. 15 to 17 and the following description, elements that are the same as or fulfill the same function as those already described above are given the same reference numerals.

Similar to the description above with reference to FIGS. 1-5, the anchor plates 22 are received in recesses 23 formed in the cover plate 8 of the secondary insulation panel 5 . The inner surface 26 of the anchor plate 22 is flush with the inner surface 27 of the cover plate 8 of the secondary insulation panel 5 . Anchor plate 22 further comprises a threaded central housing 29 that houses base 30 of primary anchor member 12 .

Preferably, the primary anchor member 12 is at least partially prefabricated. The prefabricated portion of the primary anchor member 12 includes, for example, as shown in FIG. and a seal washer 34 to which the outer axial end of the bellows is secured.

However, in such a prefabricated primary anchor member 12 , the seal washer 34 rotates integrally with the stem 31 via the bellows portion 42 . Thus, as stem 31 rotates to screw base 30 onto threaded central housing 29, seal washer 34 also rotates. However, this rotation of the seal washer 34 can create friction between the outer surface of the seal washer 34 and the secondary sealing membrane 2 , especially at the end of the screwing operation of the base 30 to the housing 29 . Such friction causes the bellows 42 to twist, which damages the bellows 42 and consequently impairs the sealability of the bellows 42 .

To prevent twisting of the bellows 42 when the base 30 is screwed to the housing 29, the body 35 of the seal washer 34 is provided on its side with a flat 85 connecting the collar 37 and the inner surface 38 of the body 35. . Similarly, the anchor shoulder portion 40 also includes a flat portion 86 . Preferably, flat portion 85 of seal washer 34 and flat portion 86 of anchor shoulder portion 40 extend in the same plane.

A method of installing primary anchor member 12 includes using a socket wrench 87 that includes an inner surface 88 complementary to flats 85 and 86 . Moreover, the height of the socket wrench 87 is preferably greater than the height of the stem 31 and at least the distance between the inner axial end of the stem and the flat portion 85 of the seal washer 34 . Thus, due to the complementarity between the inner surface 88 of the wrench and the flats 85 and 86, rotation of the wrench 87 causes rotation of both the stem 31 and thus the base 30 and seal washer 34. In FIG. 16, anchor shoulder 40 and body 35 include six flats 85 and 86, although the number and size of flats may vary and primary anchor member 12 has one flat surface complementary to inner surface 88 of wrench 87. There may be one, two or more flats 85 and 86 so that the seal washer 34 and anchor shoulder, and thus the stem 31 and base 30, rotate together when the wrench 87 is in use. It's becoming

To attach the prefabricated portion of primary anchor member 12 to anchor plate 22 , the prefabricated portion is inserted into socket wrench 87 . Wrench 87 is then rotated to screw base 30 onto housing 29 . Since the seal washer 34 is rotated together with the stem 31, no twisting of the bellows 42 due to friction between the seal washer 34 and the secondary sealing membrane 2 occurs.

Once the base 30 is fully threaded into the housing 29, a bell portion 43 may be added over the stem 31 as shown in FIG. Alternatively, in this case the prefabricated part of the anchor member may also have a bell portion 43 fixed to the stem 31, for example by welding.

In this alternative shown in FIG. 17, bell portion 43 includes a flat portion 89 similar to flat portion 86 of anchor shoulder portion 40 . Furthermore, the sealing washer 34 , more specifically the flat portion 85 , is positioned radially beyond the lip 46 of the bell portion 43 . Therefore, the inner surface 88 of the wrench 87 faces the flat portion of the bell portion 43 and the seal washer 34 for screwing the base 30 to the housing 29 as the seal washer 34 is rotated to prevent twisting of the accordion portion 42 . interacts with the plateau of

The techniques described above for manufacturing closed and insulated tanks can be used to construct different types of storage tanks, for example LNG storage tanks on land-based installations or floating structures such as LNG carriers.

Referring to FIG. 9, a cutaway view of an LNG carrier 70 shows a generally prism-shaped sealed insulated tank 71 mounted on a double hull 72 of the carrier. The walls of the tank 71 include a primary containment barrier configured to contact the LNG contained within the tank, a secondary containment barrier positioned between the primary containment barrier and the double hull 72 of the carrier, and a primary containment barrier. and two insulating barriers positioned between the containment barrier and the secondary containment barrier and between the secondary containment barrier and the double hull 72, respectively.

Connecting the loading and unloading pipelines 73 located on the upper deck of the carrier vessel with suitable connectors in a manner known per se to a sea or port terminal to transfer the LNG cargo to and from the tanks 71. can be done.

FIG. 9 shows an example of a marine terminal with loading and unloading stations 75 , submersible pipes 76 and onshore installations 77 . The loading and unloading station 75 is a fixed offshore installation comprising a movable arm 74 and a tower 78 supporting the movable arm 74 . Movable arm 74 holds a bundle of insulating flexible pipes 79 that can be connected to loading and unloading pipeline 73 . The orientable moveable arm 74 can be adjusted to fit all sizes of LNG carriers. A connecting pipe (not shown) extends inside tower 78 . Loading and unloading stations 75 allow loading and unloading from onshore facility 77 to LNG carrier 70 or from LNG carrier 70 to onshore facility 77 . The installation comprises a liquefied gas storage tank 80 and a connecting pipe 81 connected to the loading and unloading station 75 via a submersible pipe 76 . Submersible pipes 76 allow transfer of liquefied gas over long distances, e.g. be possible to keep.

Pumps onboard the carrier 70 and/or on land installations 77 and/or on the loading and unloading stations 75 are used to generate the pressure required to transport the liquefied gas.

Although the present invention has been described in connection with some particular embodiments, it is by no means limited to them if they are within the scope of the invention, and all technical equivalents of the means described and their combinations of

Use of the verb "comprise" or "comprise" and their conjugations does not exclude the presence of elements or steps other than those stated in a claim.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims (19)

A closed and insulated tank comprising a tank wall,
a secondary insulation barrier (1) configured to be fixed to a support wall, said tank wall continuing from the outside of said closed and insulated tank to the inside of said closed and insulated tank in the thickness direction of said tank wall; , a secondary sealing membrane (2) resting on said secondary insulation barrier (1), a primary insulation barrier (3) resting on said secondary sealing membrane (2), and said primary insulation barrier (3) ) and configured to be in contact with the product contained within said closed and insulated tank;
said primary insulation barrier (3) comprises a plurality of juxtaposed primary insulation panels (11),
said closed and insulated tank further comprising a plurality of primary anchor members (12) configured to be directly or indirectly retained on said support wall;
Said primary anchor members (12) each interact with at least one primary insulation panel (11) of said plurality of primary insulation panels (11) to bind said at least one primary insulation panel (11) to said configured to retain on the secondary sealing membrane (2);
Said primary anchor member (12) comprises:
a base (30) configured to be held directly or indirectly on said support wall;
A stem (31) extending through the thickness of the tank wall from the base (30) towards the primary sealing membrane (4), the stem (31) passing through an opening in the secondary sealing membrane (2). )and,
a bearing element (16,54) mounted on said stem (31) for supporting said primary insulation panel (11) to retain said primary insulation panel (11) on said secondary sealing membrane (2); a bearing element (16, 54) configured to
a seal washer (34) engaging said stem (31) between said bearing element (16) and said opening in said secondary sealing membrane (2), said central opening through which said stem (31) passes; 36) and is tightly secured to said secondary sealing membrane (2) around said opening in said secondary sealing membrane (2);
a deformable seal portion (42) sealingly connecting said seal washer (34) and said stem (31) to allow relative movement between said seal washer (34) and said stem (31); and a closed and insulated tank. The lateral dimension of said central opening (36) of said seal washer (34) is greater than said lateral dimension of the portion of said stem (31) that engages within said central opening (36); allows the stem (31) to move in the central opening (36) of the sealing washer (34) in a direction perpendicular to the thickness of the tank wall by Item 1. The closed and insulated tank according to item 1. said primary anchor member (12) further comprising a stopper provided on said stem (31);
said stopper is arranged on said stem (31) between said bearing element (16) and said seal washer (34),
Said stopper has a stop surface (47) facing said seal washer (34) so that said seal washer (34) is positioned against said stem (31) in said thickness direction of said tank wall. 3. A sealed and insulated tank according to claim 1 or 2, adapted to stop movement towards the primary sealing membrane (4). said stem (31) comprises a shoulder (48),
Said shoulder portion (48) extends laterally from said stem (31) to said central portion of said seal washer (34) such that an outer surface (49) of said shoulder portion (48) forms said stop surface (47). 4. A closed insulated tank according to claim 3, projecting beyond the opening (36). said primary anchor member (12) further comprising a bell portion (43) attached to said stem (31);
The bell portion (43) includes an attachment portion (44) and a protection portion (45),
the mounting portion (44) has a central passage through which the stem (31) passes;
The protective portion (45) extends from the mounting portion (44) toward the seal washer (34) in the thickness direction of the tank wall,
The protection part (45) is hollow,
A closed and insulated tank according to any one of the preceding claims, wherein said deformable sealing portion (42) is housed within said protective portion (45). Claim 3 citing claim 3, wherein the outer end of the protective portion (45) opposite the mounting portion (44) defines the stop surface (47) facing the sealing washer (34). Item 6. A hermetically insulated tank according to item 5. A closed and insulated tank according to claim 5 or 6, wherein said bell (43) is fixed to said stem (31). An enclosed insulated tank according to any one of claims 5 to 7, further comprising a transfer wedge positioned around said bell portion in the gap between said bell portion and said adjacent primary insulation panel. said seal washer (34) comprises a flat (85) and said bell (43) comprises a flat (89);
Said flats (85) and (89) are configured to be gripped by a fastener, said stem (31) and said seal washer (34) being attached to said deformable seal (42). A closed and insulated tank according to any one of claims 5 to 8, arranged to rotate together without twisting. said deformable seal portion comprises a deformable bellows portion (42);
said deformable bellows (42) is hollow and extends around said stem (31) along the axial direction of said stem (31);
A first axial end of the bellows portion (42) is tightly fixed to the stem (31),
A closed and insulated tank according to any one of claims 1 to 9, wherein a second axial end of said bellows (42) is tightly fixed to said seal washer (34). 11. The closed and insulated tank of claim 10, wherein said bellows (42) has at least three pleats. The bellows portion (42) has a flared shape,
The circumferential dimension of said second axial end of said bellows (42) fixed to said seal washer (34) is equal to said first axial end of said bellows (42) fixed to said stem (31). 12. A closed and insulated tank according to claim 10 or 11, which is larger than the peripheral dimension of the axial ends. A closed and insulated tank according to any one of claims 1 to 12, wherein said base (30) of said primary anchoring member (12) is rigidly fixed to said secondary insulating barrier (1). the inner end of the stem (31) opposite the base (30) is threaded;
said primary anchor member (12) further comprising a nut (32) screwed onto said threaded inner end;
said bearing element (16, 54) is inserted between said nut (32) and said base (30) of said primary anchor member (12);
A closed and insulated tank according to any one of the preceding claims, wherein said deformable seal is interposed between said bearing element (16, 54) and said seal washer (34). 15. The closed and insulated tank of claim 14, wherein a resilient washer (33) is inserted between said nut (32) and said bearing element (16, 54). said primary anchor member (12) having an anchor shoulder (40) projecting laterally from said stem (31);
said anchor shoulder (40) forms an anchor surface (41) extending in a plane perpendicular to said thickness direction,
said anchor surface (41) faces said bearing element (16, 54),
A closed and insulated tank according to any one of claims 1 to 15, wherein said deformable sealing portion is tightly fixed to said anchor surface (41). Carrier vessel (70) for transporting cryogenic liquid products, comprising a double hull (72) and a tank according to any one of claims 1 to 16 arranged in said double hull. a carrier (70) according to claim 17;
an insulated pipeline (73, 79, 76, 81) arranged to connect the tank (71) installed in the double hull of the carrier vessel to a floating body or land storage facility (77);
a pump for causing a flow of cryogenic liquid product through the insulated pipeline from the floating body or land storage facility to the tank of the carrier vessel or from the tank of the carrier vessel to the floating body or land storage facility. Transport system for transporting cryogenic liquid products. A method for loading and unloading a carrier vessel (70) according to claim 17, comprising:
Insulated pipelines (73, 79 , 76, 81) from floating or land storage facilities (77) to said tanks of said carrier vessels (70) or from said tanks of said carrier vessels ( 70 ) to floating or land storage facilities (77) A method comprising sending a cryogenic liquid product through.

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