CN113710950A

CN113710950A - Adhesive tape manufacturing method

Info

Publication number: CN113710950A
Application number: CN202080028882.6A
Authority: CN
Inventors: P·兰德鲁
Original assignee: Gaztransport et Technigaz SA
Current assignee: Gaztransport et Technigaz SA
Priority date: 2019-03-25
Filing date: 2020-03-24
Publication date: 2021-11-26
Anticipated expiration: 2040-03-24
Also published as: FR3094477A1; WO2020193584A1; CN113710950B; FR3094477B1; KR20210154144A

Abstract

A method for manufacturing an adhesive tape for mounting a sealed and thermally insulated cabinet in a supporting structure, comprising the steps of: -determining a plurality of gaps (27) distributed between a plurality of measurement points on the outer surface of the tank and the inner surface of the supporting structure, said gaps (27) being determined parallel to the thickness direction of the tank, said gaps (27) being determined as a function of the mounting position of the tank in the inner space of the supporting structure, the three-dimensional dimensions of said tank and said inner space of the supporting structure, -manufacturing an adhesive tape intended to be applied between the inner surface of the supporting structure and the outer surface of the tank, the cross-sectional dimensions of said tape being defined as a function of said determined gaps (27).

Description

Adhesive tape manufacturing method

Technical Field

The present invention relates to the field of sealed and thermally insulated cabinets with membranes. In particular, the present invention relates to the field of sealed and thermally insulated tanks for storing and/or transporting cryogenic liquefied gases, such as tanks for transporting liquefied petroleum gas (also called LPG) having a temperature of, for example, between-50 ℃ and 0 ℃, or tanks for transporting Liquefied Natural Gas (LNG) at atmospheric pressure of about-162 ℃. These tanks may be mounted on the ground or on a floating structure. In the case of a floating structure, the tank may be used to transport liquefied gas or to receive liquefied gas for use as fuel for propelling the floating structure.

In one embodiment, the liquefied gas is LNG, i.e. a mixture with a high methane content stored at a temperature of about-162 ℃ at atmospheric pressure. Other liquefied gases, in particular ethane, propane, butane or ethylene, and also hydrogen, are also conceivable. The liquefied gas may also be stored under pressure, for example at a relative pressure of between 2 and 20 bar, in particular at a relative pressure of about 2 bar. The tank can be made according to different techniques, in particular in the form of a tank integral with the membrane or a self-supporting tank.

Background

The sealed and thermally insulated tank for storing liquefied natural gas, arranged in a supporting structure, has a multilayer structure, i.e. from the outside to the inside of the tank, a secondary insulating barrier anchored to the supporting structure, a secondary sealing film located on the secondary insulating barrier, a primary insulating barrier located on the secondary sealing film and a primary sealing film located on the primary insulating barrier, the primary sealing film being intended to be in contact with the liquefied natural gas stored in the tank.

According to one embodiment of such a tank, each primary and secondary thermal insulation barrier comprises a set of thermal insulation blocks, respectively primary and secondary (according to other embodiments, the tank comprises only a single thermal insulation barrier), which are substantially parallelepiped-shaped, juxtaposed and thus form the support surface of the respective sealing membrane. The support surface must have good flatness in order to provide continuous and flat support for the sealing film. In fact, when LNG is contained in the tank, the tank walls are subjected to a great deal of thermal, hydrostatic and hydrodynamic stresses. The flat and continuous support surface allows avoiding the creation of stress concentration zones in the sealing film, which could lead to a deterioration of the sealing film.

However, although the insulating blocks have flat inner surfaces to form the support surface of the sealing membrane, the support structure on which the blocks are anchored does not always have sufficient flatness to allow the blocks anchored on the support structure to form a continuous and flat support surface. For example, in the frame of a support structure formed by the double hull of a ship, the junction areas between the different parts of the double hull form, with respect to the respective support wall, generally planar irregularities, which are connected, for example, at the weld between said two parts of the double hull.

In order to compensate for these flatness defects, adhesive tapes are generally interposed between the insulating blocks and the supporting structure, as described in FR- A-2259008. In particular, it is possible to place the adhesive tape in a plastic state on the bottom surface of the insulating block and then press it against the supporting wall, causing it to flow until the gap between the supporting wall and the insulating block when they are in their final position is exactly filled. Such tapes are described, for example, in documents FR2909356, FR2877638 or WO14057221, which describe the construction of different sealed and thermally insulated boxes integrated in different types of supporting structures.

Disclosure of Invention

The idea on which the invention is based is to provide a method for manufacturing an adhesive tape for interposition between a sealed and thermally insulated box and a supporting structure. In particular, the invention is based on the idea of making an adhesive tape with a sufficient thickness dimension to allow the formation of a support surface of the sealing film with a satisfactory flatness. The idea on which the invention is based is also to avoid excessive consumption of adhesive in the manufacture of adhesive tapes.

According to one embodiment, the invention provides a method for manufacturing an adhesive tape for mounting a sealed and thermally insulated cabinet in a support structure, said support structure comprising an inner surface delimiting an inner space,

the method comprises the following steps:

-determining a plurality of gaps distributed between a plurality of measurement points on the outer surface of the tank and the inner surface of the support structure, said gaps being determined parallel to the thickness direction of the tank at said measurement points, said gaps being determined as a function of the mounting position of the tank in the interior space of the support structure, the three-dimensional dimensions of said tank and said interior space of the support structure,

-manufacturing adhesive tape intended to be applied between the inner surface of the supporting structure and the outer surface of the tank, the cross-sectional dimensions of said tape being defined according to said determined gap.

By virtue of these features, it is possible to manufacture an adhesive tape capable of compensating for the defects in the flatness of the inner surface of the support structure. Further, the adhesive tape produced according to this method makes it possible to provide an insulating barrier having satisfactory flatness to support the sealing film.

According to one embodiment, the method of manufacturing such an adhesive tape may include one or more of the following features.

The adhesive tape can be manufactured by applying a quantity of polymerizable adhesive in a plastic state on a surface selected from the group consisting of the inner surface of the support structure and the outer surface of the tank. The cross-sectional shape of the adhesive tape thus applied may be more or less irregular, for example approximately circular. This shape is then changed to a somewhat rectangular cross-section by pressing between the inner surface of the support structure and the outer surface of the tank when the tank is placed in the support structure, and the strip is then hardened by polymerization in this somewhat rectangular shape. The cross-section of the tape when the polymerizable adhesive is applied is preferably sufficient to provide the final polymerized adhesive tape with a cross-section having a width greater than or equal to a predetermined constant. The predetermined constant (i.e., the acceptable minimum width) may be obtained by a size calculation at a previous stage.

According to one embodiment, the adhesive tape is produced continuously over a length corresponding to the length of application of said adhesive tape on the outer surface of the tank or on the inner surface of the supporting structure.

According to an embodiment, the method may further comprise:

-providing a plurality of cross-sectional dimensions, the plurality of dimensions comprising an integer number t of dimensions, the plurality of dimensions having an upper limit that is greater than a rectangular cross-section associated with a largest gap of the plurality of gaps, the associated rectangular cross-section having a predetermined width and a height equal to the largest gap of the plurality of gaps. In the method, the adhesive tape is manufactured with a cross-sectional dimension selected from the plurality of dimensions.

According to one embodiment, the integer t is less than a total number of said gaps of the plurality of gaps.

By virtue of these features, the number of different sizes of adhesive tapes to be manufactured can be limited. This manufacturing method therefore allows a simple and quick manufacturing of the adhesive tape to compensate for the flatness defects of the support structure. If the distribution of the gaps is very uneven, in particular if some very high values differ far from the rest of the distribution, it may be advantageous to treat the gaps of the several highest values separately, for example to build custom adhesive tapes for these points that differ far, and to determine a plurality of sizes only to cover the remaining gap distribution.

The invention is not limited to the realization of a limited number of optimized belt dimensions to compensate for the flatness defects of the support structure, which makes it possible to provide a flexible choice for the operator responsible for the installation/assembly of each tank into the support structure, according to two key parameters:

some adhesive tape sizes that are limited and match the flatness defects of the supporting structure, and

perfectly optimised (taking into account all structural requirements and mechanical strength) the amount of glue required to properly and durably mount/assemble the tank in the supporting structure.

Thus, based on the step of determining a plurality of gaps distributed between a plurality of measuring points on the outer surface of the tank and the inner surface of the supporting structure, that is to say substantially according to the accuracy or number of measuring points during this determination step, it is possible for the operator, by means of the method according to the invention, to prefer a limited number of strap sizes, for example a number of required adhesive strap sizes of between 3 and 8, or to prefer a perfect optimization of the amount of adhesive required for the tank mounting/assembly operation.

In fact, managing a large number of sizes of adhesive tapes may be problematic for the operator or simply impossible due to the unsuitability of the equipment for manufacturing said tapes.

In the latter case, the invention not only makes it possible to optimize the size of the adhesive tape with respect to the flatness defects of the supporting structure, so as to reduce the amount of adhesive that is technically useless, but also offers the operator the possibility of: the number of strap sizes that they need or they can use in the context of the tank's installation/assembly operations is selected.

The invention allows to achieve the best possible optimization of the glue dosage in the opposite case where the operators have equipment for manufacturing adhesive tapes, allowing them to manufacture an infinite number of adhesive tapes of sizes, and these operators choose or tend to use as many adhesive tapes as possible, which is useful or necessary for reducing the glue dosage that is not technically useful.

For all intermediate cases between the two extreme cases mentioned above, the method according to the invention provides an optimized solution, taking into account in particular, but not exclusively, the parameters relating to:

-selecting a predetermined or determinable number of sizes of adhesive tape within a certain number of sizes of adhesive tape after the step of determining a number of gaps distributed between a number of measuring points on the outer surface of the tank and the inner surface of the support structure,

the characteristics of the plant for manufacturing adhesive tapes (in particular its manufacturing capacity and its location),

the nature and characteristics of the adhesive (currently of the epoxy type, containing a high content of fillers and/or microspheres),

characteristics (number, qualification, etc.) of the operator responsible for installing/assembling the tank in the supporting structure.

According to one embodiment, for one of the plurality of gaps, an adhesive tape is produced having a cross-section dimension equal to the smallest of the dimensions greater than or equal to the dimension of the rectangular section associated with said gap, the associated rectangular section having said predetermined width and a height equal to said gap.

By virtue of these features, the adhesive tape produced can satisfactorily compensate for the flatness defects of the support structure without excessive consumption of adhesive.

According to one embodiment, the step of providing a plurality of cross-sectional dimensions comprises:

-calculating a gap occurrence frequency for a plurality of gaps,

-calculating a plurality of tape dimensions from the gap occurrence frequency and the determined gaps such that each gap of the plurality of gaps can be associated with one of a plurality of dimensions that is immediately (immdiatement) larger than the rectangular cross-section associated with said gap and such that the cumulative difference between the rectangular cross-section associated with said gap of the plurality of gaps and said dimension associated with said gap is limited.

In addition to what has been explained above, the setting of the number t of different sizes and/or the calculation of the t sizes are operations that can be performed according to different policies. For example, the setting of the number t of different sizes and/or the calculation of the t sizes may be performed for more or less larger configurations, for example for a plurality of boxes, a single box or a portion of a box, in particular for a flat wall of a polyhedral box, even for a portion of a flat wall. When the building blocks on which the calculations have been performed are smaller, the adhesive tape manufacturing tool must be reconfigured more frequently.

If the number t is very high, for example close to the total number of adhesive strips to be produced in the building block, the method is equivalent to producing each adhesive strip on a customized basis, which largely eliminates any excessive consumption of adhesive, but greatly increases the operational constraints during the installation of the tank, since each adhesive strip must be produced and transported to a precisely positioned location. In contrast, a relatively low number t, at least for the building blocks, makes it possible to standardize the manufacture of adhesive tapes and to reduce the operating limits. According to one embodiment, the integer t of the size is less than or equal to 10, preferably less than or equal to 5.

According to an embodiment, the method may further comprise:

-measuring the internal space of the support structure in three dimensions,

-defining a size and a shape of the tank according to said three-dimensional measurements to allow the insertion of said tank into the internal space of the support structure,

-defining the installation position of the tank in the internal space of the support structure, according to the three-dimensional measurement of the internal space of the support structure and to the dimensions and shape of the defined tank.

By virtue of these features, it is possible to know the gap to be exactly compensated for, thus allowing a more precise manufacture of the adhesive tape.

According to one embodiment, the tank comprises a plurality of insulating blocks comprising a bottom plate defining the outer surface of the tank, and defining the installation position of the tank comprises defining anchoring positions of the plurality of insulating blocks on the inner surface of the support structure.

According to one embodiment, one or more or each insulating block has the shape of a parallelepiped, for example a rectangular parallelepiped.

According to one embodiment, for each insulating block, the measuring points comprise points of the bottom plate of the insulating block when the insulating block is in the anchoring position.

According to one embodiment, the supporting structure comprises at least one flat supporting wall, the tank comprises a tank wall comprising a plurality of heat-insulating blocks intended to be anchored to the supporting wall, the heat-insulating blocks having an inner surface parallel to the floor, the inner surface forming a supporting surface for a sealing membrane of the tank wall, the method further comprising:

-determining a reference plane for the support wall,

and the anchoring position of the insulating block is defined such that the inner surface of the insulating block has an inclination with respect to a reference plane that is less than a threshold angle when the insulating block is in the anchoring position.

According to one embodiment, the tank wall comprises a plurality of thermal insulation blocks juxtaposed according to a regular pattern.

According to one embodiment, the sealed and insulated cabinet further comprises a sealing film on the inner surface of the insulating block.

According to one embodiment, the threshold angle is less than Arctan (10)^-2) Preferably less than Arctan (6.10)^-3)。

According to one embodiment, the adhesive tape is produced in such a way that the inner surface of the insulating block has an inclination smaller than the threshold angle with respect to the inner surface of the insulating block having adjacent anchoring locations on the supporting wall.

According to one embodiment, the adhesive tape is made with a length less than or equal to the size of the bottom plate of the insulating block.

According to one embodiment, the interior space of the support structure has a longitudinal direction, a transverse direction and a height direction, the method comprising the steps of:

-defining a central longitudinal axis of the tank, parallel to the longitudinal axis of the internal space of the support structure,

-defining a central transverse axis of the tank, parallel to the transverse axis of the internal space of the supporting structure, and

-defining a central height axis of the tank, parallel to the height axis of the internal space of the support structure.

According to one embodiment, the step of positioning the box in the internal space of the supporting structure comprises the step of defining a plurality of first positioning lines and a plurality of second positioning lines, the first positioning lines being parallel to each other and the second positioning lines being parallel to each other, the first positioning lines being perpendicular to the second positioning lines, the first positioning lines being spaced apart by a first pitch equal to the size of the first edges of the external surfaces of the insulating blocks and the second positioning lines being spaced apart by a second pitch equal to the size of the second edges of the external surfaces of the insulating blocks.

According to one embodiment, at least one of the central longitudinal axis of the tank, the central transverse axis of the tank and the central height axis of the tank defines a first or second positioning line of the tank wall and/or an axis of symmetry of said first or second positioning line of the tank wall.

According to one embodiment, the invention also provides a storage device comprising a support structure and a sealed and insulated cabinet mounted in the interior space of the support structure, the storage device comprising an adhesive tape manufactured according to the above method and applied between the inner surface of the interior space of the support structure and the outer surface of the cabinet.

Such tanks may form part of an onshore storage facility, e.g. for storing LNG, or be installed in floating, coastal or deep water structures, in particular methane tankers, floating storage regasification plants (FSRU), floating production storage offshore plants (FPSO), etc. Such tanks can also be used as fuel tanks in any type of vessel.

According to one embodiment, the invention also provides such a storage device in the form of a vessel for transporting cold liquid products, comprising a double shell forming said support structure.

According to one embodiment, the invention also provides a method for loading or unloading such a vessel, wherein the cold liquid product is transferred from the floating or onshore storage facility to the tanks of the vessel or from the tanks of the vessel to the floating or onshore storage facility through insulated pipelines.

According to one embodiment, the invention also provides a transfer system for a cold liquid product, the system comprising a vessel as described above, an insulated pipeline arranged to connect a tank mounted in the hull of the vessel to a floating or onshore storage facility, and a pump for driving the cold liquid product through the insulated pipeline from the floating or onshore storage facility into the tank of the vessel or from the tank of the vessel into the floating or onshore storage facility.

Drawings

The present invention will be better understood and other objects, details, characteristics and advantages thereof will be more clearly apparent from the following description of several particular embodiments of the invention, given by way of illustration and not of limitation, with reference to the accompanying drawings.

Figure 1 is a cross-sectional view of a support structure for receiving a sealed, thermally insulated cabinet.

Fig. 2 is a schematic view of the lateral walls of the support structure of fig. 1, showing the installation position of the insulation blocks for anchoring to the lateral support walls of the sealed insulated cabinet.

Fig. 3 is a cross-sectional view of the lateral support wall of fig. 2, illustrating a flatness defect of an inner surface of the lateral support wall.

Fig. 4 is a cross-sectional view of the lateral support wall of fig. 3, showing a best reference plane.

Fig. 5 is a view similar to fig. 4, showing the insertion of the reference plane of fig. 4 from a linear section, corresponding to the dimensions of the insulating blocks of the walls of the tank intended to be anchored to said lateral supporting walls.

Fig. 6 is a view similar to fig. 3, with insulation blocks sealing the walls of the insulated cabinet anchored thereto.

Fig. 7 is a diagram illustrating the dimensions of the adhesive tape produced according to different embodiments according to the frequency of occurrence of the gap to be compensated between the outer surface of the sealed and thermally insulated cabinet and the inner surface of the supporting structure.

Figure 8 is a schematic cross-sectional view of a tank of a methane tanker, said vessel comprising a sealed and insulated tank and a terminal for loading/unloading the tank.

Detailed Description

In the following description, the terms "external" and "internal" will be used to indicate the relative position of one element with respect to another, subject to the inside of the tank, according to the definitions given in the description. Thus, an element that is close to or facing the inside of the tank is referred to as an internal element as compared to an external element that is close to or facing the outside of the tank.

With reference to fig. 1, a support structure 1 can be seen, which is intended to receive the walls of a sealed and thermally insulated cabinet. The support structure 1 is formed by a double hull of the vessel. The support structure 1 has a substantially polyhedral shape. The support structure 1 has transverse walls 2, typically a front transverse wall and a rear transverse wall, here octagonal. In fig. 1, the front transverse wall 2 is only partially shown, so that the interior space 9 of the support structure 1 can be seen. The transverse wall 2 is an insulation bulkhead of the vessel and extends transversely to the longitudinal direction of the vessel. The support structure 1 further comprises a top wall 3, a bottom wall 4 and side walls 5. The top wall 3, the bottom wall 4 and the side walls 5 extend in the longitudinal direction of the vessel and connect the front and rear transverse walls 2.

The top wall 3 comprises, near the rear transverse wall 2, an upwardly protruding cuboid-shaped space, called a liquid dome 6. The liquid dome 6 delimits an opening 7 of the top wall 3, said opening 7 allowing the passage of a pipe for conveying liquid from or to the tank when the tank is mounted in the supporting structure 1.

The

support walls

2, 3, 4, 5 of the support structure have an inner surface 10 which delimits an inner space 9 of the receiving box. The tank comprises a plurality of tank walls, each tank wall being anchored to a respective supporting

wall

2, 3, 4, 5 of the supporting structure 1.

In the example chosen here, the tank is a tank with a membrane of multilayer structure. Each wall of the tank therefore has, in sequence from the outside to the inside in the thickness direction of the respective tank wall, a secondary insulating barrier anchored to the respective supporting

wall

2, 3, 4, 5, a secondary sealing film bearing against the secondary insulating barrier, a primary insulating barrier bearing against the secondary sealing film and a primary sealing film bearing against the primary insulating barrier for contact with the fluid contained in the tank.

By way of example, the tank wall may be manufactured according to different techniques described in FR-A-2691520, FR-A-2877638 or WO-A-14057221. In these different embodiments, each tank wall comprises a plurality of insulating blocks 11, which form at least a second insulating barrier. These insulating blocks 11 are prefabricated outside the inner space and have standardized dimensions.

According to an embodiment described, for example, in document FR2877638, the insulating block 11 is parallelepiped-shaped. The primary and secondary thermal barriers are formed by a plurality of juxtaposed such parallelepipedic thermal insulation blocks 11.

According to another embodiment, described for example in document FR2691520, the insulating block 11 comprises a portion of secondary insulating barriers and a portion of primary insulating barriers, superimposed. A sealing layer forming part of the second sealing film is interposed between the two heat insulating barrier portions. In this embodiment, the primary and secondary thermal insulation barrier portions have a parallelepiped shape, and the size of the primary thermal insulation barrier portion is smaller than that of the secondary thermal insulation barrier portion.

In all these cases, the insulating block 11 has a bottom plate forming a rectangular outer surface 12, which outer surface 12 is intended to abut against the inner surface 10 of the inner space 9. These insulating blocks 11 likewise have a flat inner surface which forms a support surface for receiving a sealing film.

However, the support structure 1 has in practice dimensions that can vary with respect to the theoretical dimensions. Therefore, dimensional variations of the support structure 1, associated for example with structural tolerances, must be taken into account in order to incorporate the sealed and thermally insulated box in the inner space 9.

For this purpose, a three-dimensional measurement of the interior space 9 of the support structure 1 is carried out. Such three-dimensional measurement of the inner space 9 is carried out in any suitable way, for example by using a laser rangefinder or a laser emitter and sensor located in the inner space 9, to measure the dimensions and arrangement of the different supporting

walls

2, 3, 4, 5.

From this three-dimensional measurement of the inner space 9, the position and dimensions of the tank to be mounted in the support structure are calculated.

More specifically, the tank walls are dimensioned and their position is determined on the one hand on the basis of the dimensions of the insulating block 11, more specifically on the basis of the dimensions of the outer surface 12 of said insulating block 11, and on the other hand on the basis of a three-dimensional measurement of the interior space 9. Since the insulation blocks 11 are anchored in a juxtaposed manner according to a regular grid structure on each supporting

wall

2, 3, 4, 5, the anchoring position of the insulation blocks 11 on the respective supporting

wall

2, 3, 4, 5 is determined for each tank wall.

For each tank wall, a grid structure 15 of the insulating blocks 11 is thus calculated. Fig. 2 shows an example of a lattice structure 15 on the transverse support wall 2. The grid structure 15 comprises a plurality of first location lines 16 and a plurality of second location lines 17. The first alignment lines 16 are parallel to each other. Likewise, the second alignment lines 17 are parallel to each other. The first alignment line 16 and the second alignment line 17 are perpendicular to each other. The first alignment lines 16 are spaced apart at a regular first pitch 18, the first pitch 18 corresponding to the size of the first side of the outer surface 12 of the insulation block 11. Likewise, the second positioning lines 17 are spaced apart at a regular second pitch 19, the second pitch 19 corresponding to the size of the second side of the outer surface 12 of the insulating block 11. These first positioning lines 16 and these second positioning lines 17 correspond to the lines along which said insulating blocks 11 are anchored to the lateral supporting walls 2, for example by means of anchoring members, not shown, such as studs. The grid structure 15 thus makes it possible to determine the position of the insulating blocks 11 on the lateral supporting walls 2.

According to one embodiment, the computing box has a central longitudinal axis (not shown), a central transverse axis 13 (see fig. 2), and a central height axis 14 (see fig. 2). These central axes are determined from three-dimensional measurements of the interior space 9. These central axes are adjusted as necessary depending on the position of the liquid dome 6 in the support structure 1 and make it possible to determine the arrangement of the grid structure 15. For example, as shown in fig. 2, the lattice structure 15 defined for anchoring the insulating blocks 11 to the lateral supporting walls 2 may be symmetrical on both sides of the central height axis 14. Furthermore, the central transverse axis 13 may determine the first positioning line 16.

In the case of A sealed and thermally insulated tank with at least one bellows-sealing membrane, as described for example in document FR- A-2691520, the lattice structure 15 on the different supporting

walls

2, 3, 4, 5 is preferably determined in such A way as to ensure continuity of the bellows between the different tank walls. In general, the positioning of the insulating blocks 11 on two adjacent supporting

walls

2, 3, 4, 5 is adjusted to form a supporting surface that allows the sealing membrane to be mounted in such a way that the corrugations can be continuous between the walls of the tank.

However, the inner surface 10 formed by the supporting

walls

2, 3, 4, 5 may have an imperfect flatness, for example due to construction tolerances or due to the assembly of the different elements forming said supporting

walls

2, 3, 4, 5. Thus, for example, a weld made between two portions of a double shell assembled together may constitute an irregular area of flatness of the inner surface 10. Also, the region including the reinforcing bead disposed between the two walls forming the double hull of the ship may also form an irregular region of flatness of the inner surface 10.

These flatness defects of the inner surface 10 must be compensated for during the seating of the insulating blocks 11. In fact, the tank wall is subjected in use to significant stresses, for example under the influence of deformations of the supporting structure 1 associated with navigation, under the influence of thermal stresses and even under the influence of the movement of the liquid in the tank. In order to avoid deterioration of the tank tightness, the sealing membrane is arranged in as flat a manner as possible. Therefore, it is important that the primary and secondary thermal barriers form a flat and continuous support surface for the sealing film. Therefore, it is necessary to compensate for the flatness defects in the inner surface 10 in order to provide a satisfactory support surface for the insulating block 11 on which the sealing film of the tank is placed.

Fig. 3 shows a transverse supporting wall 2 with such a flatness defect. These flatness defects create a more or less pronounced gap 20 between the point of the inner surface 10 and the plane midline of the support wall.

In order to compensate for these gaps 20, a reference plane 21 is determined which corresponds to the ideal position of the sealing film, i.e. the ideal position of the inner surface 22 of the insulating block 11. This reference plane 21, shown in figure 4, is substantially parallel to the median plane of the lateral supporting wall 2, that is to say it corresponds to a plane parallel to the lateral supporting wall 2, not comprising the above-mentioned flatness defects. This fig. 4 also shows a first positioning line 16.

The reference plane 21 is the best theoretical plane. It is permissible that the insulating block 11 has an inner surface 22 slightly inclined with respect to this reference plane 21, i.e. a support surface for the primary or secondary sealing film. Each insulating block 11 has an inner surface 22 at an angle to the best reference plane 21 that is less than Arctan (10)^-2) And preferably less than Arctan (6.10)^-3). Furthermore, the inner surfaces 22 of two adjacent insulating blocks 11 should form an angle not too large, preferably smaller than Arctan (10)^-2) Preferably less than Arctan (6.10)^-3). These angles correspond to a limit beyond which the supporting surface of the sealing membrane will have insufficient flatness and may, in use, create one or more stress concentration zones on the sealing membrane.

As shown in fig. 5, which shows a cross-sectional view perpendicular to the first location line 16, for each second location line 17, the reference line 23 is interpolated by a linear portion 24 from the reference plane 21. Each linear portion 24 has a size corresponding to the first interval, in other words, each linear portion corresponds to the side size of the thermal insulation block 11. The interpolation is also performed for each first definite line having a linear portion corresponding to the second interval.

In order to ensure that the insulating block 11 is anchored in a position corresponding to the respective linear portion 24 of the reference line 23, a thickness spacer 25 is arranged on or near the anchoring member intended to cooperate with the insulating block 11. The spacer 25 is dimensioned to have a constant gap between the inner surface of said spacer 25 and the reference line 23, equal to the thickness of the insulating block 21.

Further, as shown in fig. 6, an adhesive tape 26 is inserted between the outer surface 12 and the inner surface 10 of the thermal insulation block 11. These adhesive tapes 26 are made by mixing a polymerizable resin and a hardener at the manufacturing site of the box to be applied immediately on the thermal insulation blocks 11 before hardening by polymerization. This in situ manufacturing is necessary if the polymerization time of the adhesive is relatively short, e.g., about 1 hour or less.

These adhesive strips 26 make it possible to compensate for the flatness defects of the inner surface 10 and to provide support for the insulating blocks 11 between the thickness spacers 25. To this end, the adhesive tape 26 is dimensioned to fill the gap 27 between the outer surface 12 and the inner surface 10 of the insulating blocks 11, while having a surface cooperating on the one hand with the insulating blocks 11 on which they are applied and on the other hand with the inner surface 10 of the supporting structure, which is sufficient to support said insulating blocks 11 and to transmit forces between the insulating blocks 11 and the supporting structure 1. In other words, the dimensions of these adhesive strips 26 are determined according to the gap 27 measured between the outer surface 12 and the inner surface 10 of the insulating block 11 and according to the predetermined width of said mating surface.

Thus, the amount of adhesive applied in an extensible state to form the adhesive tape 26 is therefore dimensioned to have a sufficient cross section such that, in the final state, the surface for applying said adhesive tape 26 onto the insulation blocks 11 and the inner surface 10 has a width greater than or equal to a predetermined minimum width after said adhesive tape 26 is pressed between the outer surface 12 and the inner surface 10 of the insulation blocks 11 when said insulation blocks 11 are placed on the support structure 1.

The size of the cross-section of the adhesive tape is thus determined by the predetermined minimum width and the position of the adhesive tape, since the thickness dimension of the tape depends on the gap 27 to be filled at its exact location. These positions (and therefore the number of adhesive strips 26 to be placed) and the predetermined width are derived from previous calculations taking into account the mechanical bending strength of the insulating block 11.

The gap 27 is measured on the one hand from the reference line 23 and on the other hand from the previously performed three-dimensional measurement of the inner surface 10. More specifically, for each anchoring position of the insulating blocks 11 determined by the grid structure 15, a plurality of gaps 27 between the outer surface 12 of said insulating blocks 11 and the inner surface 10 of the support structure 1 are measured. In the example shown in fig. 6, three adhesive tapes 26 are interposed between each insulating block 11 and the inner surface 10 of the supporting structure 1, these tapes extending over the entire length of the insulating block 11. Thus, one or more gaps 27 are measured along each line of the outer surface 12 of the insulation block where the adhesive tape 26 is to be applied. These gaps 27 are furthermore measured in the thickness direction of the respective tank wall. In other words, the gap is measured at one or more measurement points, for example three measurement points, for each adhesive tape. If a plurality of measuring points are associated with one and the same adhesive tape, the dimensioning of the adhesive tape can be performed in a manner varying over the length of the adhesive tape or in a manner such that the average of the gaps obtained at these measuring points is uniform over the entire length of the adhesive tape.

According to one embodiment, such adhesive tape 26 is continuously manufactured by an adhesive extruder. Different techniques may be used to adjust the cross-section of the tape 26 during manufacturing.

Adjustment of the cross-section can be obtained by adjusting the flow rate of the adhesive through the dispensing head of the extruder. This flow rate adjustment may optionally be accompanied by an adjustment of the output section of the extruder dispensing head. This adjustment of the output section can be performed in different ways, for example by means of a dispensing head with an adjustable section or by means of an interchangeable dispensing head with a different fixed section.

Another way of adjusting the cross section of the adhesive tape, in particular if the adhesive has sufficient thixotropic properties, is to adjust the relative advancement rate between the dispensing head of the extruder and the surface on which the adhesive tape is applied, i.e. for example by adjusting the feed rate of the insulating blocks in the technique described in publication FR- A-2259008.

A first method of determining the size of the adhesive tape comprises customizing the size of the cross-section of each adhesive tape 26 according to the gap 27 measured at the position where the adhesive tape should occupy the support structure 1. However, this sizing method has the disadvantage that the manufacturing tool must be constantly adjusted. Therefore, the adhesive tape cannot be manufactured in a uniform manner.

To remedy this drawback, another method of dimensioning the adhesive tape consists in providing a determined number t of discrete dimensions. Although this embodiment results in greater adhesive consumption than the above-described embodiment in which each adhesive tape 26 is manufactured individually depending on its position in the magazine, it is possible to simplify the manufacturing of the adhesive tapes 26 by defining uniform dimensions, and therefore, no adjustment of the production tool is required for each adhesive tape 26 manufactured. For this reason, several methods will be described with reference to fig. 7.

Fig. 7 shows the distribution 28 of the gap 27 measured as described above. The vertical axis represents the size of the gap 27 in the thickness direction of the tank wall. This dimension can be multiplied by a predetermined width to obtain a desired cross-sectional area of the adhesive tape. The horizontal axis represents the population of measurement points, adjusted to a percentage. The distribution has been arranged in an ascending order of the gaps 27, thereby providing the frequency of occurrence of each gap in the distribution. The more frequent the gap, the wider the space it occupies in the distribution 28.

According to this embodiment, the adhesive tapes 26 are produced according to t different sizes for all the gaps 27 measured between the inner surface 10 and the outer surface of the box (typically the outer surface 12 of the insulating block 11). However, the distribution of the gap may be determined according to the scale of the construction unit except the entire tank, for example, a flat wall of the tank.

In this figure, the distribution 28 of the gap can be increased by a certain safety factor, for example by about 8%, compared to the actual measured value. This increase makes it possible to slightly oversize the cross-sectional dimensions of the adhesive tape 26 to ensure a satisfactory mating surface, that is to say to obtain, in particular by creeping, a final width greater than or equal to a predetermined width. The second curve 29 corresponds to a polynomial interpolation of the gap profile 28.

In the first modification of the present embodiment, the size of the adhesive tape 26 is determined in a uniformly distributed manner. In the example shown in fig. 7, five sizes of adhesive tape 26 (i.e., t-5), represented by numerals 31-35, are determined such that each size of adhesive tape can cover 20% of the gap distribution 28. The uniformly distributed size curve 30 shows the different sizes 31-35 by dashed lines. Thus, on this curve 30, the thickness of the first uniform distribution dimension 31 is 5.7mm, the thickness of the second uniform distribution dimension 32 is 8.4mm, the thickness of the third uniform distribution dimension 33 is 10.3mm, the thickness of the fourth uniform distribution dimension 34 is 12.9mm, and the thickness of the fifth uniform distribution dimension 35 is 23 mm. The respective cross-sections can be obtained by multiplying these thicknesses by a predetermined width.

Therefore, in the example of uniformly distributed sizes shown by the dotted lines in FIG. 7, the same number of adhesive tapes are used in each of the sizes 31-35. At a position where the gap 27 is less than 5.7mm, i.e. 20% of the minimum measurement gap, adhesive tape 26 of the first evenly distributed size 31 is used. At a position where the gap 27 is between 5.7mm and 8.4mm, i.e. also 20% of the measured gap, adhesive tape 26 according to the second evenly distributed dimension 32 is used, and so on.

Such a uniform distribution of the

dimensions

31, 32, 33, 34 and 35 facilitates the manufacture of the adhesive tape 26 and makes it possible to compensate for all measured gaps 27 simply, quickly and reliably.

However, these uniformly distributed dimensions are not suitable for producing all tanks. Since the flatness defects of the inner surface 10 vary from tank to tank, these uniformly distributed dimensions can lead to excessive consumption of adhesive when the gap 27 is mostly far from the uniformly distributed

dimensions

31, 32, 33, 34 and 35. For example, with respect to the curve 30, the fifth uniform distribution dimension 35 of the adhesive tape 26 is significantly greater than the gap 27 measured for the majority of the measurement points associated with the adhesive tape 26 of said fifth dimension 35, resulting in a significant excessive consumption of adhesive, i.e. in particular an excessive width due to excessive creep of the adhesive tape. In extreme cases, the resulting excess width may completely fill the gap between the adhesive tape 26 and the adjacent adhesive tape and thereby create air pockets trapped in the adhesive. Such air bags may be prohibited by regulations in the event that the tank should contain flammable substances.

According to a second variant of this embodiment, the discrete dimensions of the adhesive tape are determined according to the measured frequency of occurrence of the gaps 27, so as to limit the cumulative difference between the gaps 27 and said relative dimensions.

"limiting cumulative variation" means achieving a better adhesive tape size design than a uniformly distributed size. For this reason, the area 37 between the gap profile 28 and the jagged curve 36 representing the discrete size of the band, i.e., the integral of the difference between the two curves, must be minimized. This problem can be solved by numerical optimization.

The number of tape sizes t may be increased in order to limit tape loss in the manufacture of the adhesive 26. Likewise, certain measurement points may be deleted to truncate the distribution 38 and thus manually handle gaps of anomalies. For example, custom adhesive tapes may be used for a portion up to the first 2% (maximum adhesive tape) of the measured gap. In this case, t adhesive tape dimensions determined as above are used for the remainder of the measured gap.

The above-described techniques for manufacturing sealed, thermally insulated tanks may be used for different types of vessels, for example for LNG vessels constructed in onshore facilities or in floating structures such as methane tankers and the like.

Referring to fig. 8, a cross-sectional view of a methane tanker 70 shows a generally prismatic sealed insulation box 71 installed in the double hull 72 of a vessel. The walls of the tank 71 comprise a primary sealing barrier intended to be in contact with the LNG contained in the tank, a secondary sealing barrier arranged between the primary sealing barrier and the double hull 72 of the vessel, and two insulating barriers arranged between the primary sealing barrier and the secondary sealing barrier and between the secondary sealing barrier and the double hull 72, respectively.

As is well known, a loading/unloading pipe 73 located on the topside of the ship may be connected to a marine or harbour terminal by means of suitable connectors for transferring LNG cargo from or into the tanks 71.

Fig. 8 shows an example of an offshore terminal comprising a loading dock 75, a subsea line 76 and an onshore facility 77. The loading station 75 is a fixed offshore installation that includes a mobile arm 74 and a riser 78 supporting the mobile arm 74. The mobile arm 74 carries a bundle of insulated hoses 79, which can be connected to the loading/unloading duct 73. The orientable moving arm 74 is suitable for all methane carrier styles. A connection line, not shown, extends inside the riser 78. The loading and unloading station 75 allows the methane transport vessel 70 to be loaded from the onshore facility 77 or unloaded to the onshore facility 77. The onshore facility 77 includes a liquefied gas tank 80 and a connection line 81 connected to the loading and unloading station 75 by the subsea pipeline 76. The subsea pipeline 76 allows liquefied gas to be transported a significant distance, for example 5km, between the loading and unloading station 75 and the onshore facility 77, which makes it possible to keep the methane carrier 70 a significant distance from shore during the loading and unloading operation.

In order to generate the pressure required for the transfer of liquefied gas, pumps loaded in the vessel 70 and/or pumps provided with onshore facilities 77 and/or pumps provided with loading and unloading stations 75 are used.

Although the invention has been described in connection with several particular embodiments, it is clear that the invention is in no way limited thereto and that it encompasses all technical equivalents of the means described and combinations thereof if they fall within the scope of the invention.

Use of the verb "comprise" or "have" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The use of "a" or "an" for an element or step does not exclude the presence of a plurality of such elements or steps, unless indicated otherwise.

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

Claims

1. A method for manufacturing adhesive tapes (26) for mounting sealed and thermally insulated boxes in a supporting structure (1), said supporting structure (1) comprising an inner surface (10) delimiting an inner space (9),

the method comprises the following steps:

-determining a plurality of gaps (27) distributed between a plurality of measurement points on the outer surface of the tank and the inner surface (10) of the support structure (1), said gaps (27) being determined parallel to the thickness direction of the tank, said gaps (27) being determined depending on the mounting position of the tank in the inner space (9) of the support structure (1), the three-dimensional dimensions of said tank and said inner space (9) of the support structure (1),

-providing a plurality of cross-sectional dimensions (31, 32, 33, 34, 35, 36), the plurality of dimensions (31, 32, 33, 34, 35, 36) comprising an integer number t of dimensions (31, 32, 33, 34, 35, 36), the integer number t being smaller than a total number of the gaps of the plurality of gaps (27), the plurality of dimensions (31, 32, 33, 34, 35, 36) having an upper limit which is larger than a rectangular cross-section associated with a largest gap of the plurality of gaps (27), the associated rectangular cross-section having a predetermined width and a height equal to the largest gap of the plurality of gaps (27),

-manufacturing an adhesive tape (26) for application between the inner surface (10) of the supporting structure (1) and the outer surface of the tank, the cross-sectional dimension of said tape being defined according to said determined gap (27), the adhesive tape (26) being manufactured with a cross-sectional dimension selected from said plurality of dimensions (31, 32, 33, 34, 35, 36).

2. The manufacturing method according to claim 1, wherein, for one of said plurality of gaps (27), an adhesive tape (26) is manufactured having a cross-sectional dimension equal to the smallest of these dimensions (31, 32, 33, 34, 35, 36), which is greater than or equal to a rectangular section associated with said gap, having said predetermined width and a height equal to said gap.

3. The manufacturing method of claim 1 or 2, wherein the step of providing a plurality of cross-sectional dimensions (36) comprises:

-calculating a gap occurrence frequency of a plurality of gaps (27),

-calculating a plurality of adhesive tape dimensions (36) from the gap occurrence frequency and the determined gaps (27), such that each gap of the plurality of gaps (27) can be associated with one of a plurality of dimensions (36) that is immediately larger than the rectangular cross section associated with said gap, and such that the cumulative difference between the rectangular cross section associated with said gap of the plurality of gaps (27) and said dimension (36) associated with said gap is limited.

4. The manufacturing method according to any one of claims 1 to 3, wherein the setting of the integer t and/or the calculation of the plurality of dimensions are performed on a construction unit selected from a plurality of boxes, a single box, a flat wall of a polyhedral box, and a portion of the flat wall.

5. Manufacturing method according to any one of claims 1 to 4, wherein the integer t of the size is less than or equal to 10, preferably less than or equal to 5.

6. The manufacturing method according to any one of claims 1 to 5, further comprising:

-three-dimensional measurement of the inner space (9) of the support structure (1),

-determining the size and shape of the tank from said three-dimensional measurements to allow the insertion of said tank into the internal space (9) of the support structure (1),

-determining the mounting position of the tank in the interior space (9) of the support structure (1) from the three-dimensional measurements of the interior space (9) of the support structure (1) and the defined size and shape of the tank.

7. A manufacturing method according to claim 6, wherein the tank comprises a plurality of insulating blocks (11), the insulating blocks (11) comprising a floor defining the outer surface of the tank, and wherein defining the installation position of the tank comprises defining anchoring positions of the plurality of insulating blocks (11) on the inner surface (10) of the support structure (1).

8. A manufacturing method according to claim 6, wherein for each insulating block (11) the measuring points comprise points of the bottom plate of the insulating block (11) when the insulating block (11) is in an anchoring position.

9. Manufacturing method according to claim 8, wherein the supporting structure comprises at least one flat supporting wall (2, 3, 4, 5), the tank comprising a tank wall comprising a plurality of insulating blocks (11) intended to be anchored to the supporting wall (2, 3, 4, 5), the insulating blocks (11) having an inner surface (22) parallel to the floor, the inner surface (22) forming a supporting surface for a sealing membrane of the tank wall, the method further comprising:

-determining a reference plane (21) for the support wall,

and wherein the anchoring position of the insulating block (11) is defined such that the inner surface (22) of the insulating block (11) has an inclination with respect to a reference plane (21) smaller than a threshold angle when the insulating block (11) is in the anchoring position.

10. Manufacturing method according to claim 9, wherein the threshold angle is smaller than Arctan (10)^-2) Preferably less than Arctan (6.10)^-3)。

11. The manufacturing method according to any one of claims 7 to 10, wherein the adhesive tape (26) is manufactured to a length less than or equal to the size of the bottom plate of the insulating block (11).

12. Storage device comprising a support structure and a sealed and thermally insulated cabinet mounted in the inner space of the support structure, the storage device comprising adhesive tape (26) manufactured according to any one of claims 1 to 11 applied between the inner surface of the inner space of the support structure and the outer surface of the cabinet.

13. Storage device according to claim 12 in the form of a vessel (70) for transporting cold liquid products, the vessel comprising a double shell forming the support structure.

14. A transport system for cold liquid product, the system comprising a storage device according to claim 13, insulated pipes (73, 79, 76, 81) arranged to connect a tank (71) mounted in the hull of a ship to a floating or onshore storage device (77), and a pump for driving cold liquid product through the insulated pipes from the floating or onshore storage device into the tank of the ship or from the tank of the ship into the floating or onshore storage device.

15. A method of loading or unloading a storage unit as claimed in claim 34, wherein the cold liquid product is transferred from the floating or onshore storage unit (77) to the tanks of the vessel (71) or from the tanks of the vessel (71) to the floating or onshore storage unit (77) by insulated pipes (73, 79, 76, 81).