RU2762035C1 - Method for manufacturing wall of sealed and heat-insulating tank containing inter-panel insulation plugs - Google Patents

Abstract

FIELD: heat insulation.SUBSTANCE: invention relates to a method for manufacturing a wall of a sealed and heat-insulating tank. The method contains stages, at which a heat-insulating barrier is supplied, containing two insulating panels (3) forming inter-panel space (2). Next, insulating plug (1) is supplied, containing a covering part made of kraft paper completely covering an insulating central part. Then, a suction branch pipe of suction system (24) is inserted into insulating plug (1) through a hole in the covering part made of kraft paper. The next stage is to create low pressure in insulating plug (1) to reduce a thickness of mentioned insulating plug (1) under low pressure, and insert insulating plug (1) into inter-panel space (2), while maintaining the suction of suction system (24). After inserting insulating plug (1) into inter-panel space (2), the suction branch pipe is removed from the insulating plug.EFFECT: creation of a plug that will reliably fill the inter-panel space between two panels of the heat-insulating barrier, without creating a gap during the use of the tank.12 cl, 12 dwg

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of sealed and heat-insulating tanks having membranes. In particular, the present invention relates to the field of sealed and heat-insulating tanks for storing and / or transporting liquid at low temperatures, for example, tanks for transporting liquefied petroleum gas (also called LPG), having, for example, a temperature of from -50 ° C to 0 ° C, or for transporting liquefied natural gas (LNG) at a temperature of approximately -162 ° C at atmospheric pressure. Such tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank may be designed to transport liquefied gas or to receive liquefied gas as fuel for propelling the floating structure.

LEVEL OF TECHNOLOGY

Document FR2724623 or Document FR2599468, for example, discloses a wall structure for making a flat wall of a sealed and heat-insulating tank. Such a tank wall includes a multilayer structure including, from the outside to the inside of the tank, a secondary insulating barrier, a secondary sealing membrane, a primary thermal barrier and a primary sealing membrane for contact with the liquid contained in the reservoir. Such reservoirs include insulation panels positioned adjacent to each other to form thermal insulation barriers. In addition, insulating spacers are inserted between the two insulating panels to ensure the continuity of the insulating characteristics of said thermal barriers.

Document JP04194498 describes a sealed and heat-insulating tank for storing and transporting a cryogenic liquid, including a heat-insulating barrier consisting of insulating panels disposed adjacent to each other in a regular manner. Between two adjacent insulating panels, there is a flat insulating gasket to prevent the phenomenon of gas convection between the two adjacent insulating panels. Such a flat insulating gasket consists of an insulating core surrounded by a sealed plastic film bag. The flat insulating pad is inserted into the interpanel space in a state of vacuum compression, and the sealed package is pierced after insertion, allowing the flat insulating pad to expand so that it occupies the entire space between the two panels forming the interpanel space.

SUMMARY OF THE INVENTION

Applicant has found that the insulating gaskets described in document FR2724623 or FR2599468 are difficult to fit in said interpanel space. In addition, the insulating spacers do not guarantee that the insulation spacers will optimally fill the entire interpanel space. Thus, the insulating gaskets do not reliably guarantee continuous insulation in the thermal barriers, so that spaces in the thermal barriers can be conducive to the phenomenon of convection.

Applicant has also found that the flat insulating gasket described in JP04194498 ensures that the flat insulating gasket is correctly inserted into the interpanel space and that the interpanel space is properly filled. However, such a flat insulating pad, in use, can create a conduit conducive to natural convection. In fact, when the tank is cooled, the thermal compression behavior of the flat insulating pad is determined by the plastic film bag. However, the plastic film bag has a coefficient of thermal contraction that is higher than the coefficient of thermal contraction of insulation panels. Thus, Applicant has found that the flat insulating gaskets contract more strongly than the interpanel space in which they are placed, and this compression results in a gap separating the flat insulating pad and the surfaces of the panels forming the interpanel space. This gap promotes convection and adversely affects the insulation performance of the thermal barrier.

One idea underlying the invention is to provide a tank wall for the manufacture of a sealed and heat-insulating tank that does not suffer from these disadvantages. One idea underlying the invention is to provide a wall of a sealed and insulating tank in which an insulating plug securely fills an interpanel space between two adjacent panels of a thermal insulating barrier without creating a gap in said interpanel space during use of the tank.

To this end, the invention provides a sealed and heat-insulating tank wall comprising a heat-insulating barrier defining a flat support surface and a sealing membrane resting on said flat support surface of the heat-insulating barrier,

the thermal insulation barrier includes a plurality of insulation panels disposed adjacent to each other in a regular manner, facing side surfaces of two adjacent insulation panels together form an interpanel space separating said two adjacent insulation panels,

the tank wall further includes an insulating plug disposed in the interpanel space to fill said interpanel space, wherein said insulating plug includes an insulating core covered at least partially with a kraft paper cover portion,

said insulating central part includes multilayer glass wool, wherein said multilayer glass wool includes sheets of fibers superimposed on each other in the lamination direction, wherein the insulating plug is located in the interpanel space so that the lamination direction of the multilayer glass wool is parallel to the direction of the width of the interpanel space, t .e. the direction of the distance between the two facing side surfaces.

This tank wall provides good insulation performance for the thermal barrier. In particular, the tank wall has a thermal insulating barrier that provides continuous insulation regardless of the filling state of the tank.

In particular, the kraft paper cover that surrounds the insulating center of the insulating plug has a low coefficient of friction, which allows the said insulating plug to be easily and securely inserted into the entire interpanel space, but it is not as tear-resistant as PVC. The insert is facilitated by the orientation of the laminated glass wool, which effectively compresses the insulating core for the insert. In fact, this arrangement of the glass wool provides a simple and effective compression of the insulating core for insertion into the interpanel space. The arrangement of the laminated glass wool also allows for quick and easy expansion of the insulating core after inserting the insulating plug into the interpanel space, thus ensuring optimal filling of the interpanel space.

In addition, the kraft paper cover has a compression property similar to that of the insulating core, so that the insulating plug does not undergo uneven deformation, for example, it does not become wavy, and matches the size of the interpanel space regardless of the filling level of the tank.

In accordance with embodiments, such a wall may include one or more of the following features.

According to an embodiment, the direction of laminating the laminated glass wool is perpendicular to at least one of the facing side surfaces of two adjacent insulating panels forming an interpanel space.

According to an embodiment, the facing side surfaces of two adjacent insulation panels forming the interpanel space are parallel.

In accordance with an embodiment, the fiber sheets of the glass wool laminate are parallel to the surfaces of adjacent insulation panels defining the interpanel space.

According to an embodiment, the insulating core includes at least one spacer extending in a plane perpendicular to the direction of the tank wall thickness, said spacer dividing the laminated glass wool into a plurality of laminated glass wool portions aligned in said tank thickness direction.

According to an embodiment, the insulating core includes a plurality of spacers dividing the laminated glass wool into a plurality of laminated glass wool portions aligned in the direction of the tank wall thickness.

According to an embodiment, said spacers are spaced relative to each other at a distance of 5 to 20 cm in the direction of the tank wall thickness.

In accordance with an embodiment, one or all of the spacers are kraft paper.

According to an embodiment, the spacer or spacers are adhered to portions of the glass wool that separate said spacer or spacers.

According to an embodiment, the spacer or spacers extend in the width direction of the interpanel space by a distance less than the thickness of the insulation plug taken in said width direction of the interpanel space.

Due to these features, the insulating plug is stiff in the direction of thickness, which allows it to be uniformly compressed for insertion into the interpanel space. In addition, spacers allow pressure loss in the direction of the tank wall thickness by limiting convection through the laminated glass wool in the tank wall.

According to an embodiment, the insulating core includes multilayer glass wool having a density of 20 to 45 kg / m ³ .

According to an embodiment, the insulating core includes a first insulating layer made of glass wool and a second insulating layer made of glass wool, the first insulation layer and the second insulation layer are superimposed on each other in the direction of the width of the interpanel space, the multilayer glass wool of the first and the second insulating layers has a layering direction parallel to the width direction of the interpanel space, the first insulating layer and the second insulating layer being separated by a separating sheet made of fiberglass running parallel to the surfaces of the two insulating panels.

According to an embodiment, the laminated glass wool of the first insulating layer has a layering direction parallel to the width direction of the interpanel space.

According to an embodiment, the laminated glass wool of the second insulating layer has a layering direction parallel to the width direction of the interpanel space.

According to an embodiment, the glass wool laminate of the first insulation layer has a density greater than that of the glass wool laminate of the second insulation layer.

In accordance with an embodiment, the first insulating coating includes multilayer glass wool having a density of 33 to 45 kg / m³.

In accordance with an embodiment, the second insulating coating includes multilayer glass wool having a density of 20 to 28 kg / m³.

According to an embodiment, the first insulation coating includes at least one spacer, preferably made of kraft paper, dividing the laminated glass wool of said first layer into a plurality of laminated glass wool portions aligned in the direction of the tank wall thickness.

Due to these features, the insulating coating, i. E. the first insulating cover may be designed to provide a high rigidity of the insulating plug, and the insulating cover, i. the second insulating cover may be designed to provide a controlled deformation of the insulating plug in the thickness direction to facilitate its insertion into the interpanel space.

According to an embodiment, the cover portion completely surrounds the insulating core.

According to an embodiment, the cover portion includes a plurality of cover portion portions adhered to each other and / or adhered to the insulating core.

According to an embodiment, the kraft paper of the cover portion has a square meter weight of 60 to 150 g / m², and preferably 70 to 100 g / m².

In accordance with an embodiment, the cover portion has an impermeability having a leak rate that allows the seal plug to be compressed at low pressure by a suction system such as a vacuum pump or a Venturi vacuum generator.

According to an embodiment, the cover portion includes side portions, each side portion covering a corresponding surface of the insulating center portion.

According to an embodiment, the cover portion includes edge portions, each edge portion covering a corresponding edge of the insulating center portion.

According to an embodiment, the cover portion includes corner portions, each corner portion covering a corner of the insulating center portion.

In accordance with an embodiment, the various adjacent portions of the cover portion have one or more overlap regions overlapping or covered with a cover region of the adjacent portion of the cover portion.

According to an embodiment, the various adjacent portions of the cover portion are bonded to each other by adhesion on the cover areas.

According to an embodiment, the difference in thermal contraction ratio between the thermal contraction ratio of the insulating core and the thermal contraction ratio of the cover part is less than or equal to 15 × 10 ^-6 / K.

According to an embodiment, the modulus of elasticity of the cover portion is greater than the modulus of elasticity of the insulating core, so that the lining can compress the insulating core.

According to an embodiment, the thermal contraction ratio of the insulating core is 5 × 10 ^-6 / K to 10 × 10 ^-6 / K.

According to an embodiment, the thermal contraction ratio of the cover portion is 5 × 10 ^-6 / K to 20 × 10 ^-6 / K.

Due to these features, the compression of the cover by the cold does not substantially compress the insulating core. In particular, with such compression, there is no risk of deformation of the insulating core to such an extent that said insulating core takes on a wavy shape, which wavy shape can create gaps favoring convection.

In accordance with an embodiment, the insulating panels of the thermal insulation barrier include blocks of polyurethane foam.

In accordance with an embodiment, the invention also provides a method for manufacturing a wall of a sealed and heat-insulating tank, said method comprising the steps of:

provide a thermal insulation barrier for the walls of a sealed and thermal insulation tank, wherein said thermal insulation barrier includes a plurality of insulation panels disposed adjacent to each other in a regular manner, wherein the facing side surfaces of two adjacent insulation panels form an interpanel space dividing said two adjacent insulation panels ,

supplying a parallelepiped insulating plug including an insulating core, said insulating plug including a kraft paper covering part completely covering the insulating core,

insert the suction pipe of the suction system into the insulating plug through the hole in the kraft paper cover,

creating a low pressure in the isolation plug to reduce the thickness of said isolation plug under low pressure,

inserting an insulating plug into the interpanel space while maintaining the suction of the suction system to maintain a low pressure during the step of inserting said insulating plug into the interpanel space,

after inserting the insulating plug into the interpanel space, the suction tube is removed from the insulating plug so that the interior of the kraft cover is in communication with the external pressure through the hole in the kraft lining.

Thanks to these features, the insulating plug can be easily and quickly inserted into the interpanel space. In fact, an insulating plug having a kraft paper cover completely surrounding the insulating core is impermeable enough to be compressed by low pressure, while having an outer surface for easy insertion into the interpanel space. In addition, maintaining a low pressure in the plug during insertion into the interpanel space allows the plug to be kept compressed, while the plug retains a reduced thickness due to compression, making it easier to insert into the interpanel space.

In addition, simple removal of the suction tube of the suction system allows communication of the interior of the kraft paper cover with the outside environment, which allows expansion of the insulating core without the need for additional operations after placing the insulating plug in the interpanel space.

In accordance with embodiments, a method for making a tank wall includes one or more of the following features.

According to an embodiment, the reduction in the thickness of the insulating plug is such that the insulating plug has a thickness less than the width of the interpanel space.

According to an embodiment, the suction port of the suction system is adapted to pierce the kraft paper cover of the insulating plug, the step of inserting the suction tube into the isolation plug includes piercing the kraft paper cover with said suction tube of the suction system.

Thus, the step of inserting the suction nozzle into the insulating plug is quite simple, since it is simply necessary to pierce the kraft paper cover with said suction nozzle.

According to an embodiment, the suction port includes a flange, the step of inserting the suction port of the suction system into the insulating plug includes pressing the flange against the kraft paper cover.

Thus, the interaction between the suction port and the kraft paper cover occurs without significant leakage, which allows the suction system to quickly and easily create a low pressure in the kraft paper cover.

According to an embodiment, the insulating center portion of the insulation plug includes a glass wool laminate, said multilayer glass wool including a plurality of sheets of fibers superimposed on one another in the layering direction, and a suction pipe is inserted into the insulation plug on the side surface of the insulation plug, wherein said side surface is parallel to the laminating direction of the laminated glass wool.

According to an embodiment, the laminated glass wool is positioned in the parallelepiped insulation plug so that the fiber sheets are parallel to the large sides of said parallelepiped insulation plug.

According to an embodiment, the insertion of the insulating plug into the interpanel space is performed so that the direction of laminating is parallel to the support surface formed by the insulating panels of the thermal insulating barrier.

According to an embodiment, the insertion of the insulating plug into the interpanel space is performed so that the direction of laminating the laminated glass wool is perpendicular to the side surfaces of the insulating panels forming the interpanel space. In other words, the insulating plug is inserted into the interpanel space so that the fiber sheets of the glass wool laminate are parallel to said side surfaces of the insulating panels.

Due to these features, the fiber sheets of laminated glass wool with the aforementioned layering direction do not create a significant pressure loss during the low pressure stage by suction by the suction system, which ensures fast and uniform compression of the seal plug. In addition, the insertion of the end of the suction tube on the side of the cover allows the seal to be compressed without the need for excessive pumping speed of the suction system, which limits the risks of damage to the cover from excessive suction, which adversely affects the compression of the seal.

According to an embodiment, the insulating central part comprises spacers arranged parallel to the direction of layering, wherein the insulating plug is inserted into the interpanel space so that said spacers are parallel to the support surface formed by the thermal barrier.

According to an embodiment, an insulating plug is inserted into the interpanel space so that the surface through which the suction port of the suction system passes faces the inside of the reservoir.

Thus, the presence of a branch pipe passing through the surface of the insulating plug does not interfere with the step of inserting the insulating plug into the interpanel space.

According to an embodiment, the kraft paper cover has a leakage rate less than the pumping speed of the suction system.

Thus, the low pressure makes it possible to quickly and easily compress the insulating plug for insertion into the interpanel space.

According to an embodiment, the suction system has a pumping speed of 8 m ³ / h to 30 m ³ / h, preferably 15 m ³ / h.

According to an embodiment, during the insertion step, the insulating plug is guided into the interpanel space by a rigid plate-like guide.

This rigid rail allows for easy insertion of the insulating plug into the interpanel space.

According to an embodiment, the method further includes the step of cutting at least one of the side surfaces of the kraft paper cover after inserting the insulation plug into the interpanel space. The cutting is performed, for example, in the form of a knife cut, and this allows better gas circulation between adjacent insulating plugs in the thermal barrier.

According to an embodiment, the suction system is a vacuum pump. According to an embodiment, the suction system is a Venturi vacuum generator.

The tank wall may be part of an onshore storage facility, for example, for storing LNG, or it may be installed on a floating, nearshore or deep water structure, such as a methane tanker or any vessel using flammable liquefied gas as fuel, on a floating regasification unit and storage of gas (FSRU), floating installation for production, storage and offloading of oil (FPSO), etc.

According to an embodiment, the invention provides a vessel for transporting a cold liquid product that includes a double hull and a tank including the aforementioned sealed wall disposed in the double hull.

In accordance with an embodiment, the invention also provides a method for loading or unloading such a vessel, wherein a cold liquid product is supplied through insulated pipelines from a floating or land storage facility to a vessel's tank or from a vessel's tank to a floating or land storage facility.

In accordance with an embodiment, the invention also provides a cold liquid product transfer system, the system including the above vessel, insulated piping arranged to connect a vessel installed in the vessel's hull to a floating or above ground storage, and a pump for supplying a flow of cold liquid product through insulated pipelines from a floating or land storage to a ship's tank or from a ship's tank to a floating or land storage.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will become more clear, and other objects, details, features and advantages will become more apparent from the following description of several specific embodiments of the invention, which are given by way of example only and not limitation, with reference to the accompanying drawings.

FIG. 1 is a schematic exploded perspective view of an insulating plug for insertion between two insulating panels of an insulating barrier of a sealed and insulating container.

FIG. 2 is a schematic perspective view of the isolation plug shown in FIG. 1, assembled.

FIG. 3 is a schematic sectional view of the insulation plug shown in FIG. one.

FIG. 4 is a schematic perspective view of an installation for manufacturing laminated glass wool.

FIG. 5 is a schematic perspective view of the vacuum pump nozzle as it is inserted into the insulation plug shown in FIG. one.

FIG. 6 is a schematic perspective view of the isolation plug shown in FIG. 2 connected to a vacuum pump, the end of the vacuum pump pipe being inserted into said insulating plug.

FIG. 7 is a schematic perspective view of the isolation plug shown in FIG. 5 as it is inserted into the interpanel space separating two adjacent panels of the heat-insulating barrier of the sealed and heat-insulating reservoir.

FIG. 8 is a schematic exploded perspective view of an insulating plug according to the first alternative embodiment.

FIG. 9 is a cross-sectional view of an insulating plug according to a second alternative embodiment.

FIG. 10 is a schematic cutaway view of the tank of a methane tanker and a terminal for loading / unloading this tank.

FIG. 11 is a schematic illustration of an insulating plug inserted into the interpanel space using a rigid guide.

FIG. 12 is a fragmentary detail of FIG. eleven.

DETAILED DESCRIPTION OF IMPLEMENTATION OPTIONS

Traditionally, the expressions "external" and "internal" are used to define the relative position of one element relative to another with reference to the internal and external spaces of the tank. Thus, an element located near or facing the inside of the reservoir is considered to be internal, as opposed to an element located near or facing outward of the reservoir, which is considered external.

A sealed and insulating tank for storing and transporting a cryogenic fluid, such as liquefied natural gas (LNG), includes a plurality of tank walls, each of which has a multilayer structure.

Such walls of a sealed and heat-insulating tank have, in the direction from the outside to the inside of the tank, an auxiliary heat-insulating barrier resting on the supporting structure, an auxiliary sealing membrane resting on an auxiliary heat-insulating barrier, a main heat-insulating barrier resting on an auxiliary sealing membrane, and a main sealing membrane. designed for contact with liquefied gas contained in the tank.

The supporting structure can in particular be a self-supporting metal sheet or, more generally, it can be a rigid partition of any type having suitable mechanical properties. The supporting structure, in particular, can be formed by the hull or the double hull of the ship. The supporting structure includes a plurality of walls defining the overall shape of the tank, usually a multifaceted shape.

In addition, thermal barriers can be manufactured in a variety of ways from a variety of materials. Each of the thermal insulation barriers includes a plurality of parallelepiped-shaped insulation panels disposed adjacent to each other in a regular manner. Insulation panels of thermal insulation barriers together form flat bearing surfaces for sealing membranes. Insulation panels are made, for example, from blocks of polyurethane foam. Insulation panels made from blocks of polyurethane foam may additionally include a cover plate and / or a back plate, for example made of plywood.

For example, such reservoirs are described in patent application WO14057221 or FR2691520.

Placing the insulation panels adjacent to each other to form a thermal insulation barrier results in inter-panel spaces between two adjacent insulation panels 3. In other words, the inter-panel space 2 separates the facing side surfaces of two adjacent insulation panels 3 (see FIG. 7). In order to provide continuous insulation of the thermal insulation barrier, an insulating plug 1 is inserted into the interpanel space 2 separating the two facing side surfaces of two adjacent insulating panels 3. Figures 1-3 illustrate such an insulating plug 1.

The insulating plug 1 includes an insulating central part 4 covered with a covering part 5. The insulating plug 1 has a parallelepiped shape, corresponding to the parallelepiped shape of the interpanel space 2 and defining the shape of the insulating plug 1. Thus, the insulating plug 1 includes two large parallel surfaces 6 The two large surfaces 6 form a direction 7 of the length of the insulating plug 1 and a direction 8 of the width of the insulating plug 1. The side surfaces 9, extending in the direction 10 of the thickness of the insulating plug 1, connect the sides of the large surfaces 6.

The insulating core 4 is made of glass wool 11. The glass wool 11 used is a multi-layer glass wool, i. E. thanks to the method of production, a glass wool mat 11 is obtained, consisting of a plurality of interwoven parallel sheets visible to the naked eye, which are superimposed on each other in the direction 12 of layering. In other words, the fibers are predominantly oriented in planes perpendicular to the lamination direction 12.

Multilayer glass wool 11 can be produced, for example, using the horizontal conveyor belt method 13, which is schematically illustrated in FIG. 4. According to the manufacturing method, crushed sand and glass are melted in a furnace 14 at a temperature of, for example, 1300 ° C to 1500 ° C. The molten crushed sand and glass are then turned into fibers by spinning with rapid rotation. A binder is added to the fibers and the resulting mixture is placed on a horizontal conveyor belt 13 to pass through a polymerization oven 15 to cure the binder. In this case, the fibers are substantially parallel to the conveyor belt 13. The lamination direction corresponds to the vertical direction in the manufacturing device, since the lamination is due to gravity. For the manufacture of laminated glass wool, other manufacturing methods can be used.

In the embodiment illustrated in figures 1-3, the glass wool 11 of the central part 4 has a density of 22 or 35 or 40 kg / m³.

The central part 4 includes portions 16 of glass wool 11 separated by spacers 17. Spacers 17 extend perpendicular to the width direction 8 of the insulation plug 11. Spacers 17 extend along the entire length 7 and throughout the thickness 10 of the insulation plug 1. Spacers 17 are preferably adhered to the portions 16 of glass wool 11, separated by the above and delimiters 17.

Thus, FIG. 1 illustrates a central part 4 including four portions 16 of glass wool 11 separated in the width direction 8 of the insulating plug 1 by three spacers 17. FIG. 1 represents the preferred solution in terms of the number of separators, i.e. minimum number of spacers for non-convection in case of temperature gradients over 100 ° C. FIG. 3 illustrates an alternative embodiment in which the central portion 4 includes three portions 16 separated in the width direction 8 of the insulating plug 1 by two spacers 17.

The glass wool 11 is positioned in the central part 4 so that the lamination direction 12 is perpendicular to the width 8 of the insulation plug 1. In other words, the sheets of glass wool fibers 11 are substantially parallel to the width direction 8 of the insulation plug 1.

Preferably, the glass wool 11 is positioned in the central part 4 in the lamination direction 12 parallel to the thickness direction 10 of the insulating plug 1, i. E. the fiber sheets of glass wool 11 are substantially parallel to the large surfaces 6 of the insulation plug 1. In other words, the fiber sheets of glass wool 11 are substantially parallel to the width direction 8 and the length direction 7 of the insulation plug 1.

As illustrated in FIG. 1, the cover portion 5 includes a plurality of cover portion portions. In particular, the cover portion 5 includes the flat cover portion 18, the side cover portion 19, and the corner cover portion 20. The sections 18, 19, 20 of the cover part are attached, for example glued, to the central part 4.

The flat portions 18 of the cover portion cover the central portion 4 and form large surfaces 6 of the insulating plug 1. The flat portions 18 of the cover portion are rectangular and have dimensions substantially identical to those of the central portion 4 on large surfaces.

The side portions 19 of the cover portion include a rectangular center portion covering the corresponding side surface of the center portion 4. The center portion forms the corresponding side surface 9 of the insulating plug 1. The side portions 19 of the cover portion also include a folded portion 21 on either side of the center portion. The folded portions 21 extend from the longitudinal sides of the central portion. The folded portions 21 run parallel to the corresponding flat coating portion 18, covering the edge of said flat coating portion 18. The folded portions 21 are adhered to said edges of the flat portions 18 of the cover portion. In other words, the side portions 19 of the cover portion form the side surface 9 of the insulating plug 1 and also cover the central portion 4 on ribs 22 connecting said side surface 9 and the large surfaces 6.

The corner portions 20 of the cover portion cover the side portions 19 of the cover portion, forming two side surfaces 9 of the insulating plug 1 adjacent to each other. In other words, the corner portions 20 of the cover portion cover the ribs of the central portion 4 at the junction between the two side surfaces 9 of the insulating plug 1. Similar to the folded portions 21 of the side portions 19 of the cover portion, the corner portions 20 of the cover portion have corner folded portions 23 extending in parallel and covering the ends the folded portions 21 of the corresponding side portions 19 of the cover portion. The cover corner portions 20 are adhered to the cover side portions 19 that they cover.

Thus, the various cover portions 18, 19, 20 are adhered to each other and to the glass wool 11 to form a continuous cover portion 5 completely surrounding the central portion 4. In an embodiment not illustrated, the bottom and top portions 18 and 19 can be made from a single piece of kraft paper.

The cover part 5 is made of kraft paper. Kraft paper is characterized by a low coefficient of friction, which allows the insulating plug 1 to slide in the interpanel space 2 during its insertion into said interpanel space 2. In addition, the kraft paper has a coefficient of thermal contraction of about 5 to 20 × 10 ^-6 / K. Thus, kraft paper has a coefficient of thermal contraction close to the coefficient of thermal contraction of the insulating central part 4 located in the interpanel space. Thus, the insulating plug 1 has the same properties at low temperatures. In fact, the insulating core 4 is not subject to the risk of deformation due to compression due to thermal contraction of the cover section 5. In particular, the insulating core 4 is not subject to the risk of deformation in which it takes a wavy shape under the action of compression, and this wavy shape creates in the interpanel space 2 gaps that promote convection, which, therefore, deteriorates the insulating properties of the heat-insulating barrier.

The kraft paper of the cover part 5 has a square meter weight of more than 60 g / m² to eliminate the risk of rupture of the cover part 5 when the insulating plug 1 is inserted into the interpanel space. In addition, the kraft paper has a square meter weight of less than 150 g / m², so that the cover portion 5 retains sufficient flexibility to deform the insulation plug 1 when compressed, and preferably from 70 to 100 g / m².

The method for inserting the insulating plug 1 into the interpanel space is described below with reference to Figures 5-7.

First, an insulating plug 1 is supplied having the structure described above with reference to FIGS. 1-3. The insulating plug 1 has a complementary shape to the interpanel space 2, generally a parallelepiped shape, as described above.

The insertion method uses a suction system. The suction system in the remainder of the description is by way of example the vacuum pump 24 illustrated in FIGS. 6 and 7. In a non-illustrated embodiment, the suction system is a Venturi vacuum generator. The vacuum pump 24 is connected to the suction port 25 through a pump line 26. The suction branch pipe 25 has a flat round flange 27. The suction port 25 has a truncated shape so that the end opposite to the suction line 26 can pierce the kraft paper cover 5. Thus, the suction tube 25, and in particular the piercing end, is inserted into the insulating plug 1 by piercing the kraft paper cover portion 5. As a result of piercing the cover part 5, a suction hole 28 is formed in the insulating plug 1.

The suction pipe 25 is inserted into the insulating plug 1 through the cover part 5 on the side surface 9, which should face the inside of the sealed and heat-insulating container.

Preferably, the suction nozzle 25 is inserted into the insulating plug 1 on the side surface 9 perpendicular to the direction 12 of the glass wool layer 11.

In addition, the suction port 25 is inserted into the insulating plug 1 until the flange 27 comes into contact with the kraft paper cover 5.

After inserting the suction pipe 25 into the insulating plug 1 and placing it correctly, i. E. upon contact of the flange 27 with the cover part 5, the vacuum pump 24 is driven to create a low pressure in the insulating plug 1.

Preferably, the kraft paper cover 5 has sufficient impermeability despite the porosity of the kraft paper and the bonding between the different cover areas 18, 19, 20 by gluing such that the pumping speed of the vacuum pump 24 is sufficient to provide a low pressure in the kraft liner 5 - paper. In addition, the pressing force of the flange 27 on the cover part 5 makes it possible to limit the rate of leakage through the cover part 5 at the opening 28 through which the suction nozzle 25 passes. 24 so that the suction provided by the vacuum pump 24 creates a low pressure in the insulating plug 1.

The suction provided by the vacuum pump 24 has a suction rate of 8 to 30 m ³ / h. Preferably, the pumping speed is 15 m ³ / h. This pumping speed of the vacuum pump 24 allows a low pressure in the insulating plug 1 without the risk of damaging the kraft paper cover 5 due to the excessive suction speed.

Preferably, the vacuum pump 24 includes a filter for filtering possible fibers and dust from the glass wool 11, which can be sucked in by the vacuum pump 24.

In addition, the suction by the vacuum pump is preferably facilitated by the insertion of a suction port 25 on the side face 9 of the insulating plug, which is parallel to the direction 12 of the layering of glass wool 11. In fact, the insertion of the suction port 25 on the side face 9 of the insulating plug provides suction without pressure loss, associated with the layering of various sheets of fibers forming glass wool 11.

In addition, placing the glass wool 11 in the lamination direction 12 parallel to the thickness direction 10 of the insulating plug 1 makes it possible to facilitate the low pressure compression of the insulating plug 1 in the said thickness direction 10.

The presence of spacers 17 in the central part 4 makes it possible to stiffen the insulating plug 1 for uniform compression of the said insulating plug 1.

Low pressure in the insulating plug 1 leads to compression of the glass wool 11 and, therefore, of the insulating plug 1. Compression of the glass wool 1 allows the thickness of the insulating plug 1 to be reduced. uncompressed, it has a thickness greater than or equal to the width of the interpanel space 2, and in the compressed state it has a thickness less than the aforementioned thickness of the interpanel space 2. For example, in the context of the interpanel space 2 from 33 mm to 27 mm, the insulating plug 1 is designed as follows that its initial thickness, i.e. in the free state, it is 35 mm, and in the compressed state, the thickness is 25 mm.

Then the insulating plug 1 is inserted into the interpanel space 2 between two adjacent insulating panels 3 of the thermal barrier. As illustrated in FIG. 7 with arrows 29, the insulating plug 1 is inserted into the interpanel space 2 so that its large surfaces 6 are parallel to the lateral surfaces of the adjacent insulating panels 3 forming the interpanel space 2. During insertion, the suction pipe 25 is held in the insulating plug 1, and the vacuum pump 24 continuously creates low pressure in said insulating plug 1 to maintain the insulating plug 1 in a compressed state. Keeping the insulating plug 1 in a compressed state makes it easier to insert it into the interpanel space 2, since the insulating plug 1 has a thickness less than the width of the interpanel space 2.

The insulating plug 1 is inserted into the interpanel space 2 so that the side surface 9, through which the suction pipe 25 passes, faces the inner side of the tank, which facilitates the work with the assembly formed by the insulating plug 1 and the suction pipe 25. In addition, the insulating plug 1 preferably inserted into the interpanel space so that the lamination direction 12 is parallel to the width of the interpanel space 2. In addition, the spacers 17 are preferably arranged in the insulating plug 1 parallel to the support surface 30 formed by the insulating panels 3. FIG. 7, the insulating panels 3 include a polyurethane foam block 31 covered with a plywood board 32 forming a support surface 30. This arrangement of the spacers 17 makes it possible to restrict convection through the glass wool 11 in the tank wall.

After proper placement of the insulating plug in the interpanel space 2, the suction pipe 25 is removed from the insulating plug 1. Thus, the inner region of the cover part 5 communicates with the outside environment through the opening 28. This communication allows the glass wool 11 to expand in the absence of compressive stress, since the lower pressure is higher not supported in insulating plug 1. Expansion of the glass wool 11 allows the thickness of the insulating plug 1 to be increased so that the insulating plug 1 completely fills the interpanel space 2, thus ensuring proper continuous insulation of the thermal insulation barrier.

In the embodiment illustrated in Figures 11 and 12, a rigid guide system can be used as a guide tool during insertion of the isolation plug 1 into the interpanel space 2.

The guide system includes a first rigid plate 33 and a second rigid plate 37. Each of the two rigid plates 33, 37 has an L-shaped cross-section formed by a large rectangular surface 38 and a folded portion 39 extending perpendicular to the large surface 38.

The large surface 38 has dimensions similar to the large surfaces 6 of the insulating plug 1.

The inner surface of the folded portion 39 of the first plate 33 includes a handle 40. The handle is substantially centered in the longitudinal direction of said folded portion 39.

The folded portion 39 of the second plate 37 has a groove to accommodate the handle 40 when the two plates 33, 37 are mounted as shown in FIG. 11. The inner surface of the folded portion 39 of the second plate 37 has two handles 41. The handles 41 are located on either side of the groove for receiving the handle 40 of the first plate 33.

To insert the insulating plug 1 into the interpanel space 2 using rigid plates 33, 37, the insulating plug 1 is inserted between two rigid plates 33, 37. In particular, the large surfaces 6 of the insulating plug 1 are inserted and compressed between the large surfaces 38 of the rigid plates 33, 37. The folded portions 39 of the rigid plates overlap each other in the direction of the vessel wall thickness, as illustrated in FIG. 12. Such an overlap is possible by positioning the handle 40 in the groove of the folded portion 39 of the second rigid plate 37 provided for this purpose.

Then the rigid plates 33, 37, between which the insulating plug 1 is held in a compressed state, can be inserted into the interpanel space 2 with the insulating plug 1. After inserting the insulating plug 1 into the interpanel space 2, the rigid plates can be removed using the handles 40, 41, which leads to the release of the insulating plug 1 from the compressed state and its expansion, so that it occupies the interpanel space 2.

FIG. 8 illustrates a first alternative embodiment of an insulating plug 1. In the first alternative embodiment, elements identical or having the same function as those described above with reference to FIGS. 1-3 are denoted with the same reference numerals.

The first alternative embodiment differs from the insulating plug 1 illustrated in FIGS. 1-3 in that the insulating core 4 includes two insulating layers superimposed on each other in the thickness direction of the insulating plug 1.

The first insulating layer 34 has a structure similar to that of the central portion described above with reference to FIGS. 1-3, i. E. a structure including sections 16 of laminated glass wool 11, separated by spacers 17 made of kraft paper. said sections 16 of the laminated glass wool 11 have a direction of layering of the glass wool 11 parallel to the support surface 30 formed by the insulating panels 3, preferably parallel to the width of the interpanel space 2, i. e. parallel to the direction 10 of the thickness of the insulating plug 1.

The second insulating layer 35 includes one layer of laminated glass wool 11. The direction of laminating the laminated glass wool forming the second layer 35 is parallel to the support surface 30 formed by the insulating panels 3 and preferably parallel to the thickness direction 10 of the insulating plug 1.

The first insulating layer 34 and the second insulating layer 35 are separated by a separating layer 36. The separating layer 36 is made of glass fabric.

The first insulating layer 34 has a multilayer glass wool 11, the density of which exceeds the density of the multilayer glass wool 11 of the second insulating layer 35. For example, the multilayer glass wool 11 of the first insulating layer 34 has a density of 35 to 40 kg / m³, and the multilayer glass wool 11 of the second insulating layer 35 has a density 22 kg / m³.

FIG. 9 shows a second alternative embodiment of an insulating plug 1. In a second alternative embodiment, elements identical or performing the same function as those described above with reference to FIGS. 1-3 are denoted with the same reference numerals.

The second alternative embodiment is different from the first alternative embodiment illustrated in FIG. 8 in that the kraft paper cover 5 does not completely cover the insulating core 4. In fact, in FIG. 9, the second insulating layer 35 is not covered on the side surface 9 of the insulating plug 1. In other words, one of the side portions 19 of the cover portion only covers the first insulating layer 34 and includes only one folded portion 21, said folded portion 21 being adhered to the flat portion 18 of a cover portion covering the first insulating layer 34.

An insulating plug 1 according to the alternative embodiments illustrated in FIGS. 8 and 9 has good compressibility and expansion due to the second insulating layer 35, but retains rigidity to ensure uniform deformation and restricts convection through the laminated glass wool 11 due to the first insulating layer. layer 34. Thus, the insulating plug 1 can easily deform when compressed to facilitate its insertion into the interpanel space 2 and at the same time completely fills the said interpanel space 2 in the absence of compression and prevents convection in the heat insulating barrier. Compression can be realized using a suction system, for example a vacuum pump 24, in the case of an insulating plug 1 shown in FIG. 8, in which the cover portion 5 completely covers the insulating center portion 4, providing sufficient tightness to be compressed under low pressure. However, compression can be achieved without a suction system in the case of the seal plug shown in FIG. 9 in which the cover part 5 does not completely cover the insulating center part 4.

The above-described technologies for manufacturing a sealed and heat-insulating tank can be applied to various types of tanks, for example, to form the main sealing membrane of an LNG storage tank in an onshore structure or on a floating structure, for example, on a methane tanker, etc.

With reference to FIG. 10, a cutaway view of a methane tanker 70 illustrates a pressurized and insulating tank 71 having a generally prismatic shape, mounted in a double hull 72 of a vessel. The tank wall 71 includes a primary pressurized barrier for contact with the LNG contained in the tank, an auxiliary pressurized barrier located between the main pressurized barrier and the double hull 72 of the vessel, and two isolation barriers located between the main pressurized barrier and the secondary containment barrier, and between the auxiliary sealed barrier and the double body 72, respectively.

As is known, the loading / unloading lines 73 located on the upper deck of the ship can be connected by suitable connectors to a marine or port terminal for transferring LNG to or from the tank 71.

FIG. 10 shows an example of a marine terminal comprising a loading and unloading station 75, a subsea pipeline 76, and an onshore facility 77. Loading and unloading station 75 is a stationary offshore facility containing a movable boom 74 and a tower 78 that supports a movable boom 74. A movable boom 74 supports a bundle of flexible insulated pipes 79 that can be connected to the loading / unloading lines 73. Movable boom 74 can be adapted to methane tankers of all sizes. A connecting conduit, which is not shown, extends inside the tower 78. Loading and unloading station 75 allows loading and unloading of methane tanker 70 from or onto land-based structure 77. The latter contains tanks 80 for storing liquefied gas and connecting pipelines 81 connected by a subsea pipeline 76 to the loading and unloading station 75. Subsea pipeline 76 can be used to transfer LPG between loading and unloading station 75 and onshore facility 77 over a long distance, for example 5 km, allowing the methane tanker 70 to be stopped offshore during loading and unloading operations.

To create the pressure required for the transfer of the liquefied gas, pumps installed on board the vessel 70 and / or pumps installed in the ground structure 77 and / or pumps installed in the loading and unloading station 75 are used.

Although the invention has been described with reference to several specific embodiments, it is obvious that it is in no way limited by them, and that it contains all technical equivalents of the described means and their combinations, so long as they fall within the scope of the invention as defined in the claims.

The use of the verb "include", "contain" or "have" and derived forms does not exclude the presence of elements or steps other than those set forth in the claim.

In the claims, any reference position in parentheses should not be interpreted as limiting the claim.

Claims (18)

1. A method for manufacturing a tank wall, which includes the steps at which: supply a heat-insulating barrier to the walls of a sealed and heat-insulating tank, and said heat-insulating barrier comprises a plurality of insulating panels (3) disposed adjacent to each other in a regular manner, while the side surfaces of two adjacent insulating panels (3) facing each other form an interpanel space (2) separating said two adjacent insulating panels (3), supply a parallelepiped insulating plug (1) containing an insulating central part (4), said insulating plug (1) comprising a covering part (5) of kraft paper completely covering the insulating central part (4), insert the suction connection (25) of the suction system (24) into the insulating plug (1) through the hole (28) in the cover part (5) made of kraft paper, create a low pressure in the insulating plug (1) to reduce the thickness of the said insulating plug (1) under low pressure, inserting an insulating plug (1) into the interpanel space (2) while maintaining the suction of the suction system (24) to maintain a low pressure during the step of inserting said insulating plug (1) into the interpanel space (2), after inserting the insulating plug (1) into the interpanel space (2), remove the suction pipe (25) from the insulating plug (1), so that the inner space of the cover part (5) made of kraft paper communicates with the external pressure through the hole (28) in the lining (5) kraft paper. 2. A method according to claim 1, wherein the reduction in the thickness of the insulating plug (1) is such that the insulating plug (1) has a thickness less than the width of the interpanel space (2). 3. A method according to any one of claims. 1 and 2, in which the suction pipe (25) of the suction system (24) is configured to pierce the kraft paper cover (5) of the insulating plug (1), and the step of inserting the suction pipe (25) into the insulating plug (1) includes into the stage at which the lining (5) made of kraft paper is pierced by the said suction pipe (25) of the suction system (24). 4. The method according to any one of paragraphs. 1-3, in which the suction nozzle (25) comprises a flange (27), and the step of inserting the suction nozzle (25) of the suction system (24) into the insulating plug (1) includes the step of pressing the flange (27) against the cover parts (5) made of kraft paper. 5. The method according to any one of paragraphs. 1-4, in which the insulating central part (4) of the insulating plug (1) comprises a multilayer glass wool (11), wherein said multilayer glass wool (11) comprises a plurality of sheets of fibers superimposed on one another in the direction (12) of layering, and in which the suction pipe (25) is inserted into the insulating plug (1) on the side surface (9) of the insulating plug (1), while said side surface (9) is parallel to the direction (12) of laminated glass wool (11). 6. The method according to claim. 5, in which the insulating central part (4) comprises spacers (17) located parallel to the direction (12) of layering, and the insulating plug (1) is inserted into the interpanel space (2) so that said spacers (17 ) were parallel to the support surface (30) formed by the thermal insulation barrier. 7. The method according to any one of paragraphs. 1-6, in which the insulating plug (1) is inserted into the interpanel space (2) so that the surface (9) through which the suction pipe (25) of the suction system (24) passes faces the inside of the tank. 8. The method according to any one of paragraphs. 1-7, in which the kraft paper liner (5) has a leak rate less than the pumping speed of the suction system (24). 9. The method according to any one of paragraphs. 1-8, in which, at the stage of insertion, the insulating plug (1) is guided into the interpanel space using a rigid guide in the form of plates (33, 37). 10. A method according to any one of claims. 1-9, further comprising the step of cutting at least one of the side surfaces (9, 19) of the kraft paper cover (5) after inserting the insulating plug (1) into the interpanel space (2). 11. The method according to any one of paragraphs. 1-10, in which the suction system is a vacuum pump or vacuum generator with a Venturi system. 12. A method according to claim 11, wherein the suction system has a pumping rate of 8 m ³ / h to 30 m ³ / h, preferably 15 m ³ / h.

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