FR2798358A1 - Detailed structure of sealed liquid methane tank with thermal insulation integrated into load bearing structure of ship, includes series of couplings joined to main connecting ring - Google Patents

Abstract

The connecting ring includes couplings (33) parallel to the transverse bulkhead (6) of the supporting structure. The outer end (34) of each coupling is locally anchored on the longitudinal walls of the tank, along the whole intersecting edge of the tank corner. Each coupling crosses and is sealed to the secondary longitudinal flank (32) of the framework. It then crosses the primary longitudinal flank of the framework, such that the internal end of the coupler comes to rest against a primary insulation beam (58), to exert a clamping force on the connecting ring. Preferred features: The framework includes a cross-shaped, prefabricated metal beam. It is constituted by the primary longitudinal flank (43), on both sides of which are welded on its faces plane opposite, respectively the secondary flank and a transverse secondary metal strip (45) which is welded, in its turn, to transverse metal sheet of the secondary sealing barrier (23). The prefabricated cross-shaped beams (42) of reinforcement are assembled successively with each other using a transverse metal strip which overlaps the adjacent edges of the primary longitudinal flanks of the beams with lateral notches on their two opposite sides, near their welding region with the secondary transverse flanks and strips, to allow the overlapping metal strip to pass. Further details of the structure are included.

Description

WATERPROOF AND THERMALLY INSULATING TANK ENHANCED IN A SHIP HOLDER STRUCTURE WITH A SIMPLIFIED ANGLE STRUCTURE.

The present invention relates to a sealed and thermally insulating tank, in particular for the storage of a liquefied substance, such as methane, at a temperature of approximately - <B> 160 ° C, </ B>, said tank being integrated into a supporting structure ship.

French Patent No. 2,629,897 discloses a sealed and thermally insulating tank integrated in a ship-carrying structure, said tank comprising two successive sealing barriers, one primary in contact with the product contained in the tank, and the other another secondary disposed between the primary barrier and the carrier structure, said bearing structure comprising, as shown in Figure 1 of the accompanying drawings, for each vessel C, on the one hand, longitudinal walls which are substantially parallel to the axis of the vessel and respectively form the ceiling 1 and bottom 2 of the tank, and the inner blanks 3, 4, 5 of its double hull, and secondly, two transverse bulkheads 6 substantially perpendicular to the axis of the vessel, these two barriers alternating with two thermally insulating barriers, the primary insulating barrier being held in abutment against the secondary sealing barrier by means of s hooking means arranged linearly substantially continuously and mechanically linked to the secondary insulating barrier, the corner connection of the secondary primary barrier elements, in the areas where the transverse partitions meet the longitudinal walls, being made in the form of a connecting ring, whose structure remains substantially constant along the intersection edge A of a transverse partition with the longitudinal walls. Such a tank is generally in the form of a polyhedron, in particular an irregular octahedron whose tank angles generally have an opening of 90 except the front tank of the vessel which must conform to the shape of the hull and may have tank angles to 60 or 120, which requires a connecting ring that can adapt to these different angles of opening.

In this French patent No. 2,629,897, transverse partitions and the longitudinal walls of the supporting structure each comprise a pair of parallel anchoring plates welded perpendicularly to the supporting structure, all along the intersection edge, the plates of each pair being spaced apart by a distance corresponding to the thickness of the primary insulating barrier, the distance between the edge of the tank and the nearest plate corresponding to the thickness of the secondary insulating barrier. The volume defined between the intersection edge, the extension of the nearest flat on a transverse wall and the extension of the nearest flat on a longitudinal wall, is filled by means of an insulating pad and an insulating casing. secondary, after which this volume is closed by means of two metal strips continuously welded to said plates, said metal strips being in turn continuously welded to a connecting ring consisting of a metal frame with a square cross section, whose side is equal to the thickness of the primary insulating barrier. Each side of the reinforcement extends beyond the vertices of the square, to form portions of wings in extension of each anchor plate and each thin metal sheet forming the primary and secondary sealing barriers, along the transverse partition and longitudinal walls. In the parallelepipedal volume defined between the anchoring plates of each pair the connecting ring facing each other, three secondary insulating caissons are successively installed, passing through the window defined between the anchoring plate farthest from the intersection edge and the wing portion opposite the connecting ring. Of course, the median secondary insulation box is put in place last through this window. The two parallelepipedal volumes thus defined on either side of the intersection edge are then closed by metal strips which are welded continuously along their edges on the plates and the portions of adjacent wings. A primary insulation box is, of course, housed inside the square section of the frame. Finally, a secondary insulation box is placed on the other side of the closure strip of each parallelepipedic volume and a primary insulation box is placed between the two wing portions of the frame, the opposite side to each parallelepiped volume. Thus, twelve insulating boxes are required to fill an angle structure, this increases the time and cost of assembly and manufacture.

in addition, the stack of three boxes in each parallelepipedal volume must have a compressive strength sufficient to withstand the creep of the material, the subsidence of the caissons under the load of the cargo contained in the tank and the thermal shrinkage of the walls. plywood boxes. Indeed, if the stack of boxes undergoes a subsidence of a few millimeters, the inner surface of the tank increases, which causes a corresponding increase in the internal pressure, and may thus cause the rupture of the sealing barriers. In general, the overall elastic collapse of the stack of three caissons should not exceed one millimeter under load, since a break can occur with a sag of about three millimeters. In addition, since the boxes are mounted in the parallelepiped volumes at room temperature, without play, it is necessary to avoid a thermal shrinkage of the boxes as it could cause buckling of the closing metal strips of said volume, which would cause a shear welds binding to anchor plates.

This connecting ring is secured to the supporting structure by welding on anchoring plates which are themselves welded, generally perpendicular to the transverse partitions and the longitudinal walls of the vessel. Each connecting ring is thus connected by four thermal bridges to the supporting structure, all along the intersection edge of the tank angle, which is unfavorable from the point of view of thermal insulation.

Finally, the anchoring plates are welded to the inner wall of the double hull, after the step of applying the protective paint on the double hull. The continuous welding of the anchoring plates on the inner wall of the double shell generates a high heat flow which may deteriorate the paint on the outer face of the inner wall of the double shell and may cause corrosion of said inner wall of the double hull, which is intended to be in contact with the sea water, when the ship is empty and the double hull serves as ballast. To overcome this drawback, a new layer of paint is applied to the parts of the double shell deteriorated by the continuous welding of the anchor plates, but such a paint recovery provides less effective protection against corrosion and requires additional operations that cost the manufacturing cost.

The present invention is based on the following observations: the primary and secondary sealing barriers consist of thin metal sheets which are connected together, in a sealed manner, by raised edges defining deformable bellows. On the transverse walls of the tank, these bellows extend parallel to a horizontal transverse direction, while on the longitudinal walls of the tank, these bellows extend parallel to a longitudinal and horizontal direction. The primary and secondary sealing barriers extending along the longitudinal walls of the tank are fixed on the anchoring plates of the transverse partitions, this fastener having to withstand a linear tensile force of the order of ten tons per meter. (100kN per meter), when the aforementioned metal sheets are in Invar. Indeed, along the longitudinal walls of the ship, the sealing barriers undergo a tensile force of the order of five tons per meter (50kN per meter) because of the thermal contraction of the sheets in Invar constituting said barriers. sealing when the tank is filled with liquefied gas at very low boiling point. In addition, along the longitudinal walls of the tank, the sealing barriers can undergo an additional tensile or compressive force of the order of five tons per meter (50kN per meter) resulting from the bending of the hull of the vessel to the swell. Thus, in the most unfavorable cases, the maximum total load may be up to ten tons per linear meter (100kN per meter), and will be, in the most favorable cases, at least zero, to avoid putting the barriers compression sealing, which would otherwise cause buckling Invar sheets, and could destroy the sealing barriers. More specifically, the dynamic stress exerted on sealing barriers along the longidutinal walls of the tank, due to the flexion of the hull to the swell, is higher at the ceiling of the tank, and of the order of five tonnes per meter (50kN per meter), whereas it is substantially zero at about half-height of the tank and simply of the order of three tonnes per meter at the bottom of the tank (30kN per meter) ). Along the transverse walls of the tank, the primary and secondary sealing barriers are fixed to the anchoring plates welded to the longitudinal walls of the tank, namely the ceiling walls, bottom and side walls. Firstly, the metal sheets of the sealing barriers along the transverse bulkheads do not undergo the dynamic stress resulting from the deformation of the shell to the swell, which therefore requires a less resistant fixing for anchoring on the walls. longitudinal dimensions of the tank, only remaining the static stress of thermal origin. In addition, the fixing of the sealing barriers along the transverse partition 6 on the ceiling 1 or the bottom of the tank C undergoes a stress almost zero, of the order of 50 Kg per meter (per meter), because the thermal stress is canceled by the bellows between the metal sheets of the sealing barriers, these bellows to open to compensate for the thermal contraction of said sheets. On the other hand, the fixing of the sealing barriers along the transverse partitions 6 to the side walls 3 to 5 of the tank C undergoes a thermal stress which is equal to a tensile force of approximately five tons per meter (50kN per meter) for the intermediate side wall 4 and the component of this same force in the direction perpendicular to the inclined side walls 3 and 5 for these walls. Thus, the invention is based on the principle that the peripheral connecting ring along the intersection edge of a tank angle undergoes variable intensity stresses in its anchoring zones on the longitudinal walls of the tank and much greater intensity constraints in its anchoring zones on the transverse walls of the tank.

The invention aims to optimize the structure of the connecting ring of the tank, according to the local constraints on its anchoring zones to the carrier structure. The invention also aims to reduce the thermal bridges between the sealing barriers of the vessel and the carrier structure, as well as to reduce the number of insulating boxes to be assembled at the vessel angles. The invention also aims to provide a vessel whose connecting ring does not damage the paintings of the double hull. Another purpose of the invention is to propose a vessel whose connection ring has a lightened and simplified structure, while retaining good resistance to static stresses of thermal origin and to dynamic stresses due to deformations of the hull of the ship. swell, in particular because of the rolling and pitching of the ship.

For this purpose, the subject of the invention is a sealed and thermally insulating tank integrated in a ship-carrying structure, said tank comprising two successive sealing barriers, one primary contact with the product contained in the tank, and the other another secondary disposed between the primary barrier and the carrier structure, the sealing barriers being constituted by thin metal sheets with a low coefficient of expansion, interconnected by raised edges forming elastically deformable bellows, at least one thermally insulating barrier being provided between the carrier structure and the secondary sealing barrier and / or between two sealing barriers, said support structure comprising, for each vessel, on the one hand, longitudinal walls which are substantially parallel to the axis of the vessel and on the other hand, two transverse bulkheads substantially perpendicular to the axis of the ship, corner connection of the primary and secondary sealing barrier elements, in areas where the transverse partitions meet the longitudinal walls, being in the form of a connecting ring which extends all along the edge of the intersection of a transverse partition with the longitudinal walls, each transverse partition comprising a pair of parallel anchoring plates and welded to said transverse partition along the intersection edge, said plates being parallel to the longitudinal walls of the vessel; and spaced from each other by a distance corresponding to that between the two sealing barriers, the distance between the tank ridge and the nearest plate corresponding to that between the bearing structure and the barrier of secondary sealing, each connecting ring comprising a metal frame of which two parallel primary and secondary parallel longitudinal wings extend in e extension two aforementioned dishes so that the outer ends of said longitudinal wings, with respect to the interior of the tank, are secured to said plates and the inner ends of said longitudinal primary and secondary wings are secured respectively to the longitudinal metal sheets of the barriers of primary and secondary sealing, the transverse metal sheets of the sealing barriers being secured to the primary longitudinal wing of said armature, the armature further comprising a secondary transverse wing extending in the extension of the transverse metal plates of the secondary sealing barrier between the two aforementioned longitudinal wings to connect them together, characterized in that the connecting ring comprises a plurality of couplers extending parallel to the transverse partition of the supporting structure, the outer end of e each coupler being locally anchored on the longitudinal walls of the tank, all along the intersection edge of the vessel angle, each coupler passing through, in a sealed manner, the secondary longitudinal wing of said frame, then passing through the primary longitudinal wing of said armature, so that the inner end of said coupler bears against a primary insulating beam to exert a clamping force on the connecting ring. Thus, thanks to the invention, it has removed the pair of anchors on the longitudinal walls of the vessel, in the vicinity of the intersection edges, replacing them with a plurality of localized anchor points, which greatly reduces the thermal bridges between the sealing barriers and the double hull. In addition, the welding of the couplers on the longitudinal walls of the tank, does not risk damaging the paint ballast level, because the thermal energy is insufficient.

Advantageously, the aforementioned reinforcement comprises a prefabricated metal beam with a cross-shaped profile, this beam consisting of the aforementioned primary longitudinal wing, on either side of which, are welded on its opposite flat faces, respectively the secondary transverse wing supra and a secondary transverse metal strip which is welded, in turn, to the transverse metal sheets of the secondary sealing barrier. In this case, the cross-profile prefabricated beams of the armature are successively assembled to one another via a transverse metal strip which overlaps the adjacent edges of the secondary transverse wings and the adjacent secondary transverse bands. , for a sealed weld, to ensure the continuity of the secondary sealing barrier, the primary longitudinal wings of said beams having lateral notches on their two opposite sides, in the vicinity of their weld zone with the wings and the transverse strips secondary, to allow the passage of said metal strip overlap.

Preferably, a metal seal cover is provided to cover both the secondary transverse wings of two adjacent beams, the intermediate overlap strip and the secondary longitudinal wing, said joint cover being welded thereto to ensure the continuity of the barrier secondary sealing.

According to another characteristic of the invention, the volume defined between the intersection edge and the extension of the nearest anchor plate is filled with an insulating lining and a secondary insulating box, the volume defined between the two dishes. anchoring and the secondary transverse wing of the frame is filled with another secondary insulating box, a volume defined between the two longitudinal primary and secondary wings of the frame and its secondary transverse wing, the opposite side to the plates of anchorage, is filled with a primary insulating box, and the volume defined between the primary longitudinal wing of the armature and the extension to the transverse metal plates of the two sealing barriers is filled by the clamping beam against which rests the inner end of each coupler. An angle structure is thus obtained with only the assembly of five boxes, instead of twelve.

In a particular embodiment, each coupler comprises a bushing welded at its base to a longitudinal wall of the supporting structure, a first threaded rod at its two opposite ends, to be screwed respectively in said sleeve and in an internally threaded metal sleeve a low expansion coefficient metal connector having a threaded portion being screwed into said sleeve and a threaded portion in which a second threaded rod is screwed to its two opposite ends, said connection representing a peripheral collar flange which comes to sealing, in a sealed manner, the secondary longitudinal wing of the frame which is traversed by said connector, the upper end of said second rod being screwed into a nut which bears, preferably via Belleville washers; and a metal support plate, s on the clamping beam of the reinforcement to the supporting structure. Preferably, a nut is housed integral in rotation in the aforesaid bushing, the external threaded end of the first rod being screwed into said nut, the bearing surface between the nut and the bushing being of the frustoconical surface / spherical surface type, to reduce the thermal bridge between the temperature of the inner wall of the double hull of the ship and that of the coupler. Typically, the temperature of the double-shell inner wall is -20 ° C, and at the base of the coupler, the temperature reaches -21 ° C, so that the thermal drop at the anchor points of the couplers to the supporting structure, is weak.

Advantageously, the number per linear meter and / or the diameter of the couplers along the intersection edges of the transverse partitions with the ceiling or the bottom of the tank is (are) lower than the number per linear meter and / or the diameter of the couplers along the intersecting edges of the transverse partitions with the other longitudinal walls of the tank. For example, a coupler per linear meter with a diameter of 10 mm is sufficient at the anchorage on the ceiling and bottom of the tank, while two couplers per linear meter with a diameter of 16 mm are required for anchoring on the other longitudinal walls of the tank.

For the front tank of the vessel, the longitudinal walls of the tank substantially conform to the shape of the hull of the ship, so that said longitudinal walls are inclined relative to the transverse bulkheads, for example at an angle of 60 or 120, the watertight passage of the secondary longitudinal wing of the armature by the intermediate connection of each coupler being effected by means of a low expansion coefficient pressed metal cup, which is welded at its outer periphery to said secondary longitudinal wing and its center, to said peripheral collar of the intermediate connection.

According to yet another characteristic of the invention, the first rod of each coupler extends substantially between the carrying structure and the secondary longitudinal wing of the armature, passing between secondary insulating caissons, and the second rod of the same coupler. also passes between primary insulating boxes located between the two longitudinal primary and secondary wings of said frame. At the intersection edge between a transverse partition and the ceiling or the bottom of the supporting structure, the inner end of the second rod of each coupler bears, for example by means of a metal plate. , straddling two adjacent clamping beams, a groove being advantageously provided on the faces facing said clamping beams to accommodate the upper portion of said second rod. At the intersection edge between a transverse partition and the longitudinal walls of the tank other than the ceiling and the bottom, the second rod of each coupler passes alternately through a groove provided the faces facing a pair of clamping beams and the center of each clamping beam. Preferably, the clamping beam is a composite beam consisting of a plywood frame and filled with foam, the inner end of said second rod resting on a plywood portion of the frame said beam. Advantageously, the composite beam is prefabricated with a primary metal strip mounted on one of its lateral faces and intended to be welded in a sealed manner to the primary sealing barrier, metal cladding then being necessary to ensure the continuity of the primary sealing barrier, at the tank angle.

To better understand the object of the invention will now be described, by way of purely illustrative and non-limiting example, an embodiment shown in the accompanying drawing.

In this drawing - Figure 1 is a partial schematic perspective view of the interior of a tank to which the present invention can be applied; FIG. 2 is an enlarged partial view, in section along a median horizontal plane of a tank according to the present invention, at the intersection edge between a transverse partition and a longitudinal longitudinal wall of the double hull; ; Figure 3 is a view similar to Figure 2, but in a median vertical section of the tank of Figure 1, at the intersection edge between a transverse wall and the bottom of the tank; Figure 4 is a partial view, enlarged and in perspective of the cross-shaped metal beam the frame of the connecting ring of the vessel of the invention; - Figure 5 is a partial view in section along the line V-V of Figure 4; FIG. 6 is an exploded perspective view of a clamping beam used in the bowl angle illustrated in FIG. 2; - Figure 7 is a view similar to Figure 6, but in the assembled position, ready for mounting in the tank; FIG. 8 is a partial and enlarged view of the assembly of the coupler illustrated in FIG. 2; FIG. 9 is an exploded perspective view of the clamping beam illustrated in FIG. 3; - Figure 10 is a partial view in section along a median horizontal plane of the front vessel of a vessel, according to the present invention; FIG. 11 is a diagrammatic, partial and enlarged view of the structure of the connecting ring illustrated in FIG. 2; and Fig. 12 is an enlarged view of the coupler passage illustrated in Fig. 10 through the secondary sealing barrier.

Referring to FIG. 2, an angle of the tank C of the invention is partially seen, said angle being formed between a transverse partition 6 of a double partition serving as separation between two tanks, and an internal wall 4 of the double hull of the vessel, the transverse partition and the wall 4, which are part of the bearing structure of the vessel, forming between them an angle of 90 and defining an intersection edge A. The assembly of the transverse partitions to the longitudinal walls of the vessel the tank is made by welding.

in a manner known per se, the tank comprises a secondary insulation barrier fixed on the carrying structure of the vessel. The secondary insulation barrier consists of a plurality of parallelepiped insulating boxes 7 which are arranged side by side, so as to substantially cover the inner surface of the carrier structure. Each secondary insulating box 7 consists of a parallelepiped box made of plywood, for example 1.2 m × 1 m. Each box has internally at least one carrying brace 8 in plywood, interposed between the two large faces of the box. Each box is filled with a particulate insulating material 9, for example pearlite. The bottom plate 10 of each box which rests on flanges of polymerizable resin 11, protrudes from the side wall of the box on the two short sides 12. On this overflowing portion of the box, there are provided cleats 13 which constitute means of fixing the boxes 7. These cleats 13 cooperate with retaining members consisting of pins 14 welded to the bearing structure of the vessel. These studs 14 cooperate with a nut 15 which bears, via a metal plate 16, said cleats 13. The tightening of the nut 15 which applies the plate 16 to the cleats 13, therefore allows. caissons 7 adjacent to studs 14 considered. In fact, the cleat 13 extends substantially over most of the width of the short side of the box and two studs 14 cooperate with the same cleat 13. In the interspaces between the boxes 7, insulating liners 17 are inserted. This insulating gasket may be fiberglass.

The casing 7 has on its face opposite to that bearing cleat 13, another cleat 18 which extends over a substantial portion of the height of the box. A metal plate 19 straddles the cleats 18 of two adjacent boxes 7 to serve as a bearing surface for a nut 20 which is screwed onto a threaded end of a rod 21 whose opposite threaded end is screwed into a sleeve 22 welded to the ship carrier structure.

On the secondary insulating barrier, the secondary sealing barrier is constituted by Invar 23 strakes with raised edges 24. The strakes 23 have a very small thickness, for example of the order of 0.5 -0.7 mm. At the right of the rods 21, the strakes 23 are pierced and is engaged in the hole thus formed a threaded base 25 until a peripheral collar of said base comes to rest on the strake 23 to achieve a weld all around said flange to seal the secondary sealing barrier.

The primary insulation barrier consists of a plurality of primary insulating boxes 26 which are held in position by anchoring members 27 which are screwed into the aforementioned bases 25. Each box 26 consists of a rectangular parallelepiped box made of plywood a height lower than the boxes 7, and also filled with particulate material, such as perlite. In a similar way, the casings 26 comprise, on their short sides, cleats against which comes to rest a nut screwed on the upper end of the anchoring members 27 constituted by threaded rods. The interspaces between the caissons 26 are also filled with glass wool 17.

The primary sealing barrier consists of Invar strakes 28, which are welded together by their raised edges 29.

The general structure of the tank which has just been described is defined in more detail in French Patent No. 2,527,544.

Although this is not shown, it is possible to interpose between the rolls of polymerizable resin 11 and the supporting structure, a film of polyane or any other material, to prevent the resin of the bead from sticking to the supporting structure and thus to allow a dynamic deformation of the carrier wall without the secondary insulating boxes 7 do not undergo the forces due to said deformation between the fixing means of the boxes 7 on the carrier structure.

We will now describe more specifically the realization of the connecting ring which will be implemented in the bowl angle, along the intersection edge A.

Two anchoring plates 30, 31 are welded substantially perpendicularly to the transverse partition 6, and extend in a direction parallel to the longitudinal wall 4. The distance between the two anchoring plates 30, 31 corresponds to the thickness of the primary insulating barrier. The volume defined between the edge A and the extension of the anchoring plate 30 is filled with the insulating material 17 and a secondary insulating box 7. After this, an Invar strip 32, 1.5 mm thick, forming a secondary longitudinal wing of the frame of the connecting ring is continuously welded at one end to the anchoring plate 30, and at its end opposite the Invar strakes 23 of the secondary sealing barrier. This band 32 is pierced for the passage of a coupler 33. This coupler 33 comprises a sleeve 34 welded at its base to the wall 4 of the supporting structure, a nut 35 housed in the sleeve 34 and integral in rotation thereof a first rod 36, a threaded end of which is screwed into the nut 35 and whose opposite threaded end 36a is screwed into a metal sleeve 37 which has an upper flange 37a radially projecting to bear against the lower face of the band 32, as best seen in Figure 8. An Invar fitting 38 has a threaded lower portion 38a which is screwed into said sleeve 37 and an upper portion 38_b which has a thread for receiving the lower threaded end of a second rod 40. Between the two portions 38_a and 38b of the coupling 38 is provided a base 39 is welded at its periphery to the strip 32.

The strip 32 is also screwed, as visible at 41 in FIG. 11, to the secondary insulating box 7 underlying.

Another secondary insulating box 7 is then mounted between the extension of the two anchoring plates 30, 31. A cross-profile metal beam 42, 1.5 mm thick, is then placed, as best seen on the FIG. 4. This beam 42 consists of an Invar strip 43 forming a primary longitudinal wing of the reinforcement of the connecting ring, of a secondary transverse wing 44 which is welded, on one side of the strip 43, perpendicular to it, so as to come welded by its opposite edge on the strip 32 mentioned above. The transverse wing 44 has folded edges at right angles to its two opposite sides. On the other side of the strip 43, the beam 42 comprises a metal sheet 45 which is welded substantially perpendicularly to the strip 43 and which is intended to seal in an airtight manner by its opposite edge on the strakes 23 of the barrier. secondary sealing. As best seen in FIGS. 4 and 11, the primary longitudinal wing 43 of the beam 42 is screwed at 46 to a secondary insulating box 7 and at 47 to a primary insulating box 26, respectively on either side of the strip. 44 of the beam 42. The strips 44 and 45 are in the extension of one another, on both sides of the strip 43. As can be seen in the figure, the beam 42 has several cross-shaped profiles. which are joined to each other by an elongated strip 48 which provides continuity of the secondary sealing barrier and is welded overlap on adjacent metal strips 44, 45. this effect, notch 43a is provided on each side of the primary longitudinal wing 43 to allow the insertion of the strip 48. A metal cover 49 is welded in a sealed manner to both the strip 48 and two adjacent secondary transverse wings 44 and secondary longitudinal wing 32, to ensure the continuity of the secondary sealing barrier. The screw fasteners at 41 and 46 do not need to be sealed because they are located inside the secondary insulating barrier. Similarly, the screw fasteners 47 are also not waterproof because they are located inside the primary insulating barrier. .

Referring to Figure 5, we see that the beam 42 has a single weld core 50 of 4 mm gauge to connect the plates 43 to 45 together.

An Invar strip 51 is fixed on the one hand with a primary longitudinal wing 43, on the opposite side to the plate 31, without this fastening being sealed, and at its opposite end on the metal strakes 28 of the primary sealing barrier. as shown in FIGS. 4 and 11. However, before setting up the strip 5, primary insulating box 26 is installed between the secondary longitudinal wing 32 and the projecting portion of the primary longitudinal wing 43.

The metal strip 51 is pierced for the passage of the second rod 40 of the coupler 33.

Another metal strip 52 is welded, on the one hand, to the metal strakes 28 of the primary sealing barrier along the transverse partition 6, and on the other hand, to the metal strip 51, to ensure the continuity of the primary sealing barrier, as best seen in Figure 11.

Referring again to FIGS. 2 and 8, it can be seen that the upper end 40a of the second rod 40 is threaded and is screwed into a nut 55 which bears, via a plurality of Belleville washers 56 and a metal plate 57 against a composite beam 58, which bears on the metal strip 51 above. The second rod 40 of the coupler 33 passes through the beam substantially at its center or is engaged in lateral grooves 58a. As best seen in FIGS. 6 and 7, the composite beam 58 consists of four bottom boards 59, two upper planks 60, two plywood side walls, an intermediate plywood partition 62 and several transverse struts in plywood 63 which bear on said lateral plates 61 and intermediate 62 to allow tightening of the nut 55. The remainder of the composite beam 58 is filled with a rigid foam 64. The beam 58 is a pressing beam.

FIGS. 6 and 7 also show cleats 65 which bear against the upper plates 60 of the composite beam 58. The beam 58 may be prefabricated with the sheet 52 which is fixed to a lateral wall of the beam 58, as visible in the figure, and in this case, side covers 66 are necessary to ensure the continuity of the primary sealing barrier.

Referring now to Figure 3, we see a tank angle at the intersection A between a transverse wall 6 and the bottom wall 2 of the bearing structure of the vessel. The only difference with respect to FIG. 2 resides in the coupler 133 whose constituent parts are identical to the coupler 33 and bear the same reference numerals increased by a hundred, except that the diameter of the rods 136 and 140 is 10 mm instead of 16 mm for coupler 33. The aforementioned beam 58 is replaced here by a primary insulating casing 158 of the same type as the casings 26 above, except that it has on its two short sides a groove 158a for receiving the second rod 140 of the coupler 133, level of the interface between two boxes 158. It should be noted that the aforementioned beam 58 also has similar grooves 58_a on each small side for the passage of the couplers 33. Indeed, in the case of Figure 2, the number of couplers 33 per linear meter is twice the number of couplers 133 in the context of Figure 3.

Referring more particularly to FIG. 9, the primary insulating casing 158 comprises a cover 160 and a waiting batten 165, as well as an intermediate partition 162 which extends perpendicularly to the grooves 158a, unlike the intermediate partition 62 of FIG. the beam 58 which extends parallel to the grooves 58a. The casing 158 may be filled with perlite.

Referring finally to Figures 10 and 12, there is shown a vessel front tank C 'according to the invention. Here, the lateral longitudinal walls 4 'of the tank <B> C </ B> form an angle of about 60 with respect to transverse partition 6 furthest from the bow of the ship and an angle of about 120 with respect to the transverse partition 6 closest to the bow of the ship. As a result, the secondary insulating boxes 7 'located between the two anchoring plates 30', 31 'no longer have a rectangular parallelepiped shape, and the primary insulating boxes 26' situated between the two longitudinal primary and secondary wings of the frame of the connecting ring, have a trapezoidal section shape. In Figure 10, it is found that the plates 30 'and <B> 31' </ B> are parallel to the wall 4 ', and thus inclined relative to the transverse partitions 6. The beams 58' also have a trapezoidal section. The couplers 33 in FIG. 10 are parallel to the transverse partition 6, so that they pass inclinedly through the secondary sealing barrier and are fixed in an inclined manner on the wall 4 '. Referring more particularly to FIG. 12, it can be seen that an Invar-shaped cup 70 is welded centrally to the base 39 of the connector 38 and at its periphery, on the secondary longitudinal wing 32, so as to cover the large hole 32_a for the passage of the coupler 33. The wings of the metal beam are not here perpendicular to each other.

The various plates constituting the connecting ring are screwed in several places on the primary and secondary insulating boxes, in order to avoid any bloating of said sheets, under the helium pressure which circulates inside the primary and secondary insulating barriers. .

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.

Claims (11)

1. A vessel (C, C ') sealed and thermally insulating integrated in a vessel carrying structure, said vessel having two successive sealing barriers, one primary (28) in contact with the product contained in the vessel, and the another secondary (23) arranged between the primary barrier and the supporting structure, the sealing barriers consisting of thin metal sheets (23, 28) with a low coefficient of expansion, interconnected by raised edges forming elastically deformable bellows (24, 29), at least one thermally insulating barrier (7, 26) being provided between the supporting structure and the secondary sealing barrier and / or between the two sealing barriers, said support structure comprising, for each tank, on the one hand, longitudinal walls (1-5, 4 ') which are substantially parallel to the axis of the ship and, on the other hand, two transverse partitions (6) substantially perpendicular to the axis of the ship, the corner connection of the primary and secondary sealing barrier elements, in areas where the transverse partitions meet the longitudinal walls, being made in the form of a connecting ring which extends all along of the intersection edge (A) of a transverse partition with the longitudinal walls, each transverse partition comprising a pair of anchoring plates (31, 30 ', 31') parallel and welded to said transverse partition along the intersection edge, said plates being parallel to the longitudinal walls of the tank and spaced from each other by a distance corresponding to that between the two sealing barriers, the distance between 'edge (A) of tank and the plate (30, 30 ') closest corresponding to that between the supporting structure and the secondary sealing barrier (23), each connecting ring comprising a metal frame including two longitudinal wings the primary (43, 51) and secondary (32) parallels extend in the extension of the two aforementioned dishes so that the outer ends of said longitudinal wings, with respect to the inside of the tank, are secured to said plates and the ends internal said longitudinal wings primary and secondary are respectively secured to the longitudinal metal sheets of the primary (28) and secondary (23) sealing seals, the transverse metal sheets of the sealing barriers being secured to the primary longitudinal flange (43, 51 ) of said armature, the armature further comprising a secondary transverse wing (44) extending in the extension of the transverse metal plates of the secondary sealing barrier (23), between the two longitudinal wings mentioned above to connect them together characterized by the fact that the connecting ring has a plurality of shots their (33, 133) extending parallel to the transverse partition (6) of the carrier structure, the outer end (34, 134) of each coupler being locally anchored to the longitudinal walls of the vessel, all along the intersecting angle of the vessel angle, each coupler traversing, in a sealed manner, the secondary longitudinal wing (32) of said armature, then passing through the primary longitudinal wing (51) said armature, so that the inner end (55) of said coupler bears against a primary isolation beam (58, 158) to exert a clamping force on the connecting ring. 2. Tank according to claim 1, characterized in that 'aforesaid frame comprises a prefabricated metal beam (42) profile cross-shaped, said beam consisting of the primary longitudinal wing (43) above, of share and other of which are welded on its opposite planar faces, respectively said secondary transverse wing (44) and a secondary transverse metal strip (45) which is welded, in turn, to the transverse metal sheets of the secondary sealing barrier (23). 3. Tank according to claim 2, characterized in that the prefabricated beams (42) cross-shaped profile of the armature are successively assembled to each other via a transverse metal strip (48) comes overlapping the adjacent edges of the secondary transverse wings (44) and adjacent secondary transverse strips (45) for a sealed seal, to ensure continuity of the secondary sealing barrier, the primary longitudinal wings (43) of said beams comprising lateral notches (43a) on their two opposite sides, in the vicinity of their weld zone with the wings and the secondary transverse strips, to allow passage of said overlapping metal strip. 4. Tank according to one of claims 1 to 3, characterized in that the volume defined between the intersection edge (A) and the extension of the anchor plate (30, 30 ') closest is filled an insulating lining (17) and a secondary insulating casing (7), the volume defined between the two anchoring plates (30, 31, 30 ', 31') and the secondary transverse flange (44) of the armature is filled with another secondary insulating box (7, <B> T), </ B> the volume defined between the two longitudinal primary (43) and secondary (32) wings of the frame and its transverse wing secondary (44), on the opposite side to the anchor plates, is filled with a primary insulating box (26, 26 '), and the volume defined between the primary longitudinal wing (43) of the frame and the extension towards the transverse metal plates of the two sealing barriers (23, is filled by the clamping beam (58, 158) against which rests the inner end of each pair ur. 5. Tank according to one of claims 1 to 4, characterized in that each coupler (33, 133) comprises a sleeve (34, 1) welded at its base to a longitudinal wall of the carrier structure, a first rod ( 36, 136) threaded at its two opposite ends, to be screwed respectively in said sleeve and in an internally threaded metal sleeve (37, 137), a metal fitting (38, 138) with a low coefficient of expansion comprising a threaded portion ( 38a) being screwed into said sleeve and a threaded portion (38 #) in which a second threaded rod (40, 140) is threaded at its two opposite ends, said fitting representing a peripheral flange with a peripheral flange (39) which comes to weld, in a sealed manner, to the secondary longitudinal wing () of the armature which is traversed by said coupling, the upper end (40a) of said second rod being screwed into a nut (55 ) which is supported, preferably via Belleville washers (56) and a metal support plate (57), on the beam (158) for clamping the armature to the supporting structure. 6. Tank according to claim 5, characterized in that, for the front tank (C ') of the vessel, the longitudinal walls (4') of the tank substantially conform to the shape of the hull vessel, so that said longitudinal walls are inclined relative to the transverse bulkheads (6), for example at an angle of 60 or 120, the watertight passage of the secondary longitudinal wing (32) of the armature by the intermediate connection (38) of each coupler (33) effected by means of a low expansion coefficient metal cup (70), which is welded at its outer periphery to said secondary longitudinal wing and at its center, to said peripheral collar (39) of the intermediate fitting. 7. Tank according to claim 5 or 6, characterized in that the first rod (36, 1) of each coupler (33, 133) extends substantially between the bearing structure and the secondary longitudinal wing (32) of the frame, passing between secondary insulating boxes (7), and the second rod (40, 140) of the same coupler also passes between primary insulating boxes (26) located between the two longitudinal primary (32) and secondary (43) longitudinal wings. ) of said armature. 8. Tank according to one of claims 5 to 7, characterized in that at the intersection edge (A) between a transverse wall (6) and the ceiling (1) or the bottom (2) of the supporting structure, the upper end of the second rod (140) of each coupler (133) abuts, for example by means of a metal plate, straddling two adjacent primary insulating beams (158), a groove (158 is advantageously provided on the faces facing said beams to accommodate the upper portion of said second rod. 9. Tank according to one of claims 5 to 7, characterized in that at the intersection edge (A) between a transverse wall (6) and the longitudinal walls (3-5, 4 ') of the tank other than the ceiling (1) and the bottom (), the second rod (40) of each coupler (33) passes alternately through a groove (58a) provided on the faces opposite a pair of beams of tightening (58) and the center of each clamping beam. 10. Tank according to one of claims 5 to 9, characterized in that a nut (35) is housed integral in rotation in the sleeve (34, 134) above, the outer threaded end of the first rod (36, 136) being screwed into said nut, the bearing surface between the nut and the sleeve being of the frustoconical surface / spherical surface type, to reduce thermal bridge between the temperature of the inner wall (2, 4, 5) of the double hull of the ship and that of the coupler. 11. Tank according to one of claims 1 to 10, characterized in that the number per linear meter and / or the diameter couplers (133) along the intersection edges (A) of the transverse partitions (6) with the the ceiling (1) or the bottom (2) of the tank (C, C ') is (are) less than the number per linear meter and / or the diameter of the couplers (33) along the intersection edges ( A) transverse partitions (6) with the other longitudinal walls of the tank (3-5, 4 ').