Guiding device for cryogenic fluid loading and / or unloading tower

Abstract

The present invention relates to a guide device (16) intended to allow the positioning of a cryogenic fluid loading and / or unloading tower relative to a base of a storage tank, the guide device (16) comprising a first portion (18) intended to be integral with a base of the tower and a second portion (20) intended to be in contact with the base, the second portion (20) being configured to carry a buffer (30), the first portion (18) comprising at least one oblique wall (22) and the second portion (20) comprising at least one angled wall (26), the guide device (16) comprising an adjustment means (32) configured to slide the angled wall (26) along the oblique wall (22).

Description

[0001] The present invention relates to the field of cryogenic fluids such as liquefied natural gas, liquefied petroleum gas, ethane, ammonia or even hydrogen, and more particularly to the problems linked to their loading and unloading resulting from their transport.

[0002] Liquefied natural gas, or LNG, is an important energy source that consists primarily of methane. Liquefied natural gas is typically stored in a liquid state at a temperature close to -160°C, with the liquefied natural gas occupying 1 / 600th of the volume it would occupy in a gaseous state. This facilitates the transport of this liquefied natural gas between an extraction site and a destination site. For and during its transport, liquefied natural gas is stored in leak-proof, thermally insulated tanks. Such tanks can be installed on land or on a floating structure.

[0003] In order to load and unload the tanks in which liquefied natural gas is stored, loading and / or unloading towers are installed within them. The loading and / or unloading towers can be mobile devices, but in the case of LNG tanks they are generally attached directly to the tank. The tank then includes an upper opening configured to receive the loading and / or unloading tower, the latter having several masts extending over the entire height of the tank. On the bottom of the tank is fixed a base on which the loading and / or unloading tower is positioned to allow the loading and unloading of liquefied natural gas.

[0004] During loading and unloading of the tank, significant temperature variations due to the change from the storage temperature of methane in the liquid state to ambient temperature can alter the materials used in the loading and / or unloading tower. By alteration of the materials, we understand that these can expand or shrink depending on the temperature variations. It is then necessary for the loading and / or unloading tower to be mobile in vertical translation on the base to adapt to the alterations of the materials, such vertical translation being understood to be substantially perpendicular to the bottom of the tank.

[0005] It is known to use buffers or pads that allow vertical translational mobility of the loading and / or unloading tower while restricting its movements in planes parallel to the bottom of the tank. Such buffers are carried by buffer supports, which are guiding devices fixed under the tower and positioned opposite the base in order to slide along the latter. The installation of the buffer supports and their assembly are however complicated to implement and require several intermediate positioning steps.

[0006] The present invention aims to overcome this drawback by proposing a buffer support whose shape facilitates the installation of a loading and / or unloading tower within a liquefied natural gas storage tank, in particular by reducing the number of steps required for assembly between the loading and / or unloading tower and the tank.

[0007] The main subject of the present invention is thus a guide device intended to allow the positioning of a cryogenic fluid loading and / or unloading tower relative to a base secured to a bottom of a cryogenic fluid storage tank, the guide device comprising a first portion intended to be secured to a base connecting masts of the liquefied natural gas loading and / or unloading tower and a second portion intended to be in contact with the base, the second portion being configured to carry a buffer, the first portion comprising at least one oblique wall and the second portion comprising at least one slanted wall, the guide device comprising an adjustment means configured to slide the slanted wall along the slanted wall.

[0008] The guiding device according to the invention is a buffer-carrying device which constitutes an interface between a loading and / or unloading tower for cryogenic fluid such as liquefied natural gas or LNG on the one hand and a base of a storage tank on the other hand, the base being more particularly intended to be positioned opposite a base of the loading and / or unloading tower. The guiding device participates in the installation of the loading and / or unloading tower relative to the base.

[0009] The guide device comprises a first portion and a second portion which are made of stainless steel. The first portion is intended to be secured to the loading and / or unloading tower, in particular to its base, while the second portion is intended to come into contact with the base. In order to manage this contact between the second portion and the base, this second portion is equipped with a buffer.

[0010] The first portion and the second portion both have a wedge shape, the shape of the first portion and the shape of the second portion being complementary. Here, the term "wedge shape" means that each of the first portion and the second portion comprises at least two walls oriented relative to each other at an angle of between 30 and 60°, preferably an angle of 45°. One of these walls corresponds to the oblique wall for the first portion, and to the angled wall for the second portion. Within the guide device, the oblique wall and the angled wall are opposite each other, or even in contact with each other. They also extend in the same plane. The oblique wall constitutes one end of the first portion while the angled wall is one end of the second portion.

[0011] In order to allow adjustment of a positioning of the guide device relative to the base, the second portion is movable relative to the first portion. Such movement is ensured by an adjustment means, which is in particular a screwing means. This adjustment means is thus configured to slide the wall at an angle along the oblique wall.

[0012] The movement of the second portion relative to the first portion allows the positioning of the buffer carried by the guide device relative to the base to be adjusted. This reduces the number of steps required for installing the loading and / or unloading tower; it is no longer necessary to successively assemble and disassemble the guide device to position it correctly, the sliding of the second portion along the first portion being sufficient to adjust it.

[0013] According to an optional characteristic of the invention, the slanted wall and the oblique wall are parallel to a sliding direction of the second portion relative to the first portion.

[0014] The sliding of the second portion relative to the first portion allows the latter to move both in a vertical direction, substantially perpendicular to a bottom of the storage tank with which the base is secured, and in a horizontal direction, substantially parallel to the bottom of the tank.

[0015] According to an optional characteristic of the invention, the guide device comprises at least one buffer configured to come into contact with the base during a movement of the loading and / or unloading tower along its extension axis.

[0016] This buffer, or pad, is a protective element that absorbs any shocks when the second portion is moved toward the base. The buffer is configured to allow the loading and / or unloading tower to move in the vertical direction but to prevent the loading and / or unloading tower from moving in the horizontal direction.

[0017] According to an optional characteristic of the invention, the buffer is arranged on a side of the second portion extending in a plane intersecting the wall at an angle.

[0018] The sloping wall and the flank extend more precisely in two planes forming an angle of 30 to 60 °, preferably 45 °. Within the second portion, the buffer protrudes from the flank and projects on either side of it.

[0019] According to an optional characteristic of the invention, the adjustment means comprises at least one positioning means provided with a head and a body, one bearing on the second portion and the other being engaged in the first portion.

[0020] In other words, the positioning means, for example a screw, extends at a first of its ends through the first portion and at a second of its ends through the second portion. The body of the positioning means corresponds in particular to its portion which comprises a thread. According to the embodiments, either the head bears on the second portion and the body is engaged in the first portion, or conversely the body bears on the second portion and the head is engaged in the first portion. The screw has nuts at each of its ends or it has a nut at one of its ends and the screw head without a nut at the other end.

[0021] According to an optional characteristic of the invention, the positioning means comprises an end portion which extends through an oblong-shaped orifice provided in one of the portions, the end portion of the positioning means being movable in translation within the orifice in a plane defining the oblong shape of the orifice.

[0022] According to the embodiments, the oblong-shaped orifice is provided either in the first portion or in the second portion. This oblong orifice is through so as to receive the end portion of the positioning means in order to adjust the guide device. Within the oblong orifice, the positioning means moves in a translational movement, in the transverse direction.

[0023] According to an optional characteristic of the invention, the guiding device comprises a means for guiding the second portion relative to the first portion.

[0024] Such a guide means ensures that the slanted wall slides along the transverse wall without offset in a plane perpendicular to the plane in which the walls extend. In other words, this guide means forms a stop in a direction perpendicular to the walls.

[0025] According to an optional characteristic of the invention, the guide means comprises at least one rebate secured to one of the portions and in sliding contact with the other of the portions, the rebate extending along the oblique wall and the slanted wall.

[0026] According to alternative embodiments, either the guide means extends from the first portion, or it extends from the second portion. In the presence of a single rebate, this is arranged on one side of the oblique wall and the slanted wall, overlapping it. In the presence of a plurality of rebates, for example two rebates, these are arranged on either side of the oblique wall and the slanted wall, so as to form a corridor for guiding the sliding.

[0027] The invention further relates to a loading and / or unloading tower configured for loading and / or unloading liquefied natural gas into a storage tank, comprising at least one guide device as mentioned previously, a plurality of masts and the base connecting the masts together, the guide device being secured to the base and configured to come into contact with the base secured to a bottom of the storage tank.

[0028] Within the loading and / or unloading tower, the base corresponds to a frame that connects the masts to each other. The base is integral with the guide device; more precisely, it is welded to the latter, in particular to its first portion. The loading and / or unloading tower comprises at least one guide device. Preferably, the loading and / or unloading tower comprises a plurality of guide devices distributed around the base.

[0029] According to an optional characteristic of the invention, the base has a through opening provided opposite the guide device.

[0030] The through opening is more precisely arranged opposite a contact zone between the second portion of the guide device and the base secured to the tank. This through opening allows operations to be carried out to check and control a position of the second portion against the base.

[0031] The invention also relates to a liquefied natural gas storage tank, comprising a loading and / or unloading tower as mentioned above, the base and a bottom wall with which the base is secured, the guide device being configured to block the loading and / or unloading tower in a plane substantially parallel to the bottom wall while allowing translation of the loading and / or unloading tower in a direction substantially perpendicular to the bottom wall.

[0032] In other words, within the storage tank, movement of the loading and / or unloading tower in the vertical direction is permitted, but movement in the horizontal direction is blocked by the guide device. The storage tank is, for example, the tank of a floating structure, this storage tank being watertight and thermally insulated.

[0033] Furthermore, the invention intends to cover a method of assembling a storage tank as mentioned previously, comprising a step of pre-positioning the guide device on the base, a step of lowering the loading and / or unloading tower towards the base, and a step of adjusting the guide device during which the second portion translates along the first portion until the guide device is in contact with the base.

[0034] The assembly method according to the invention allows the loading and / or unloading tower to be installed within the storage tank for the purpose of loading or unloading liquefied natural gas. The adjustment step is carried out by means of the adjustment means; it consists of moving the second portion of the guide device towards the base until it comes into contact with the latter, such moving resulting from the sliding of the second portion along the first portion. Once the second portion is in contact with the base, the guide device blocks a horizontal translation of the loading and / or unloading tower while allowing its vertical translation.

[0035] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and examples of embodiment given for informational and non-limiting purposes with reference to the appended drawings on the other hand, in which: [ Fig. 1 ] illustrates, schematically, a storage tank for liquefied natural gas, comprising a tower for loading and / or unloading the liquefied natural gas, the loading and / or unloading tower having a base opposite a base of the tank; [ Fig. 2 ] illustrates, schematically, a plurality of guide devices arranged between the base and the base of the figure 1 ; [ Fig. 3 ] illustrates, schematically, one of the guidance devices of the figure 2 in a first position, in which it is at a distance from the base; [ Fig. 4 ] illustrates, schematically, the guiding device of the figure 3 in a second position, in which it is in contact with the base; [ Fig. 5 ] illustrates, schematically, a sectional view of the guide device in the second position of the figure 4 , this guide device being equipped with an adjustment means; [ Fig. 6 ] illustrates, schematically, a top view of the base through which the guide device of the figures 3 à 5 .

[0036] The features, variants and different embodiments of the invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the state of the prior art.

[0037] In the figures, elements common to several figures retain the same reference.

[0038] In the detailed description which follows, the terms “vertical” and “horizontal” refer to the orientation of the guide device according to the invention. A vertical direction corresponds to a main direction of elongation of the guide device, this vertical direction being parallel to a vertical axis V of a reference frame V, H illustrated in the figures. A horizontal direction corresponds to a direction substantially parallel to a bottom wall of a storage tank within which the guide device is located, this horizontal direction being parallel to a horizontal axis H of the reference frame V, H and this horizontal axis H being perpendicular to the vertical axis V.

[0039] There figure 1 thus schematically illustrates a storage tank 1 for a cryogenic fluid, for example liquefied natural gas. It may be envisaged, without departing from the scope of the invention, that the cryogenic fluid is alternatively liquefied petroleum gas, ethane, ammonia or even hydrogen. The storage tank 1 is the tank of a floating structure, for example a ship intended for the treatment of liquefied gas such as an LNG carrier, or even a land-based installation or a gravity platform. The storage tank 1 comprises a bottom wall 2 which corresponds to its floor. The storage tank 1 further comprises side walls, which with the bottom wall 2 participate in delimiting a storage volume for the liquefied natural gas. The walls of the storage tank 1 are provided with at least one layer of thermal insulation covered by a sealing membrane, which is intended to be in contact with the liquefied natural gas.

[0040] On the bottom wall 2 of the storage tank 1 is arranged a base 4 of conical shape. This base 4 projects from the bottom wall 2 in a vertical direction V substantially perpendicular to the bottom wall 2. The base 4 constitutes a base intended to receive other elements of the storage tank 1.

[0041] As part of the elements supported by the base 4, the storage tank 1 comprises at least one loading and / or unloading tower 6 configured for loading and / or unloading liquefied natural gas into the storage tank 1. In other words, the loading and / or unloading tower 6 allows the delivery and / or evacuation of liquefied natural gas to or from the storage tank 1. The loading and / or unloading tower 6 extends between a ceiling wall of the storage tank and its bottom wall 2, more precisely the base 4. The loading and / or unloading tower 6 is for example installed within the volume of the storage tank 1 through a cover of this storage tank 1 equipping its ceiling wall.

[0042] The loading and / or unloading tower 6 extends in a main extension direction which is substantially parallel to the vertical direction V, i.e. substantially perpendicular to the bottom wall 2. The loading and / or unloading tower 6 extends between a first end 8 arranged opposite the ceiling wall of the storage tank 1 and a second end 10 arranged opposite the bottom wall 2. More specifically, the first end 8 is opposite the cover while the second end 10 is in contact with the base 4.

[0043] The loading and / or unloading tower 6 comprises a plurality of masts 12. As illustrated here, the loading and / or unloading tower 6 comprises three masts 12, which form a tripod. These three masts 12 are secured at the second end 10 of the loading and / or unloading tower 6 by a base 14, which is a plate substantially parallel to the bottom wall 2 connecting the masts 12 to each other.

[0044] The base 14 corresponds to the part of the loading and / or unloading tower 6 which is positioned opposite the base 4. Due to this arrangement of the base 14 relative to the base 4, the loading and / or unloading tower 6 is maintained in a vertical position within the storage tank 1, in particular when this loading and / or unloading tower 6 is at least partially immersed in the liquefied natural gas.

[0045] During the installation of the loading and / or unloading tower 6 within the volume of the storage tank 1, the base 14 is positioned relative to the base 4 by means of at least one guide device 16, this guide device 16 having more particularly the function of allowing a vertical translation of the loading and / or unloading tower 6 relative to the base 4 while preventing a displacement in a plane substantially parallel to the bottom wall 2.

[0046] The guide device 16 will now be described in relation to the figures 2 à 6 The storage tank 1 here comprises several guide devices 16, which are arranged around the base 4. Unless otherwise stated, the characteristics described in relation to one of these guide devices 16 are intended to apply, mutatis mutandis, to all of the guide devices 16.

[0047] The guide device 16 comprises a first portion 18 intended to be secured to the base 14 of the loading and / or unloading tower 6 and a second portion 20 intended to come into contact with the base 4, these portions 18, 20 being for example made of stainless steel. The first portion 18 and the second portion 20 are hollow boxes which have complementary wedge shapes. In other words, the first portion 18 has a wedge shape and the second portion 20 has a wedge shape, the shape of the first portion 18 and that of the second portion 20 being complementary. The term "wedge shape" means that the first portion 18 and the second portion 20 each have walls which form between them an angle of between 30° and 60°, preferably an angle of 45°.Thus, the first portion 18 comprises at least one oblique wall 22 which is oriented at 45° relative to a lateral wall 24 of the first portion 18 extending mainly in the vertical direction V. In the same way, the second portion 20 has at least one slanted wall 26, which is oriented at 45° relative to a lateral flank 28 extending mainly in the vertical direction V. In other words, within the first portion 18 of the guide device 16, the oblique wall 22 and a lateral wall 24 of the first portion 18 form an angle of between 30 and 60°. Similarly, within the second portion 20 of the guide device 16 the slanted wall 26 and a lateral flank 28 of this second portion 20 form an angle of between 30 and 60°.

[0048] The side wall 24 and the side flank 28 are arranged in substantially parallel planes and are both opposite the base 4. Due to the box shape of the guide device 16, the first portion 18 comprises two oblique walls 22 symmetrical with respect to each other and the second portion 20 comprises two slanted walls 26 symmetrical with respect to each other.

[0049] The oblique wall 22 constitutes an end wall of the first portion 18 in the vertical direction V, this oblique wall 22 being turned towards the bottom wall 2 of the storage tank 1. The slanted wall 26 is similarly an end wall of the second portion 20 in the vertical direction V, which is itself oriented towards the ceiling wall of the storage tank 1. Within the guide device 16, the oblique wall 22 of the first portion 16 is arranged opposite the slanted wall 26 of the second portion 20.

[0050] Within the guide device 16, the first portion 18 comprises a cover wall 27. This cover wall 27 extends mainly in a vertical-horizontal plane. The cover wall 27 extends, in the vertical direction V, between the oblique wall 22 of the first portion 18 on the one hand and the base 14 of the loading and / or unloading tower 6 on the other hand. More precisely, the cover wall 27 has a first end in contact with the oblique wall 22 and a second end in contact with the base 14. The cover wall 27 is in particular secured to the base 14 by welding along its second end.

[0051] It should be noted that the cover wall 27 has a shape that flares from its first end to its second end. In fact, the cover wall 27 has at its second end two ridges 27A, 27B. These ridges 27A, 27B make it possible to increase the dimension of the second end of the cover wall 27 in the horizontal direction H, and thus to increase a welding zone of the cover wall 27 to the base 14. The ridges 27A, 27B also make it possible to better distribute the stresses between the guide device 16 and the base 14.

[0052] The second portion 20 of the guide device 16 is equipped with a buffer 30 or pad. This buffer 30 corresponds to a protection device, which is configured to allow movement of the loading and / or unloading tower 6 in the vertical direction V but to prevent movement of this loading and / or unloading tower 6 in directions parallel to the bottom wall 2.

[0053] The buffer 30 is disposed on the lateral flank 28 of the second portion 20. More specifically, the buffer 30 projects from this lateral flank 28 towards the base 4. Furthermore, in certain embodiments the buffer 30 also projects from the lateral flank 28 opposite the base 4.

[0054] The buffer 30 is intended to come into contact with the base 4. To do this, the second portion 20 is movable between a first position in which the buffer 30 is at a distance from the base 4 and a second position in which this buffer 30 is in contact with the base 4. The first position is illustrated in figure 3 while the second position is represented at the figure 4 .

[0055] As illustrated in the figure 4 , there is a space D between a plane in which an edge of the shoulder 27A, 27B which is opposite the base 4 extends and a plane in which a face of this base 4 intended to be in contact with the buffer 30 extends. Such a space D is present in the first position of the second portion 20 as in its second position, that is to say that the buffer 30 is at a distance from the base 4 or in contact with this base 4. The space D is for example 10 mm when the buffer 30 is in contact with the base 4. This space D makes it possible to avoid contact between one of the masts 12 of the loading and unloading tower 6 and the base 4 in the event of collapse of the loading and unloading tower 6.

[0056] A transition from the first position to the second position results from a sliding of the slanted wall 26 of the second portion 20 along the oblique wall 22 of the first portion 18. Such sliding occurs in a sliding direction parallel to both the slanted wall 26 and the oblique wall 22. This sliding can therefore be broken down into a first vertical component and a second horizontal component, i.e. parallel to the bottom wall 2 of the storage tank 1.

[0057] The sliding of the second portion 20 relative to the first portion 18 is ensured, within the guide device 16, by an adjustment means 32. This adjustment means 32, which here takes the form of a screwing system, is particularly visible at the figure 5 . The adjustment system 32 comprises at least one positioning means 34, which here corresponds to a screw 34 comprising a head 36 and a body 38, this body 38 being equipped with a thread. The body 38 of the screw 34 extends, within the guide device 16, between the first portion 18 and the second portion 20. More precisely, the body 38 of the screw 34 extends through a first partition 40 which vertically closes the first portion 18, and through a second partition 42 which vertically closes the second portion 20. The first partition 40 and the second partition 42 both extend substantially parallel to the bottom wall 2 of the storage tank 1.

[0058] Within the first portion 18, the body 38 of the screw 34 extends through an orifice 44 formed in the first partition 40, visible in figures 5 And 6. Similarly, within the second portion 20 the body 38 of the screw 34 extends through a hole 46 formed in the second partition 42, illustrated in figure 5 . The orifice 44 and the hole 46 are opposite each other in the vertical direction V. According to the embodiment shown in the figures, in the first portion 18 the thread of the body 38 of the screw 34 is engaged in the first partition 40, more precisely in its orifice 44, whereas in the second portion 20 the head 36 of the screw 34 is supported on the second partition 42. For the first portion 18, the screw 34 is retained in the vertical direction V by a nut 48 embedded on the thread of the screw 34. However, one could imagine, without departing from the scope of the invention, embodiments in which the head 36 of the screw 34 is supported on the first partition 40, the thread being retained in engagement by the nut 48 in the second partition 42, or even embodiments in which the head 36 of the screw 34 is also a carrier of a 48 nut.

[0059] As is particularly visible in figure 6 , the orifice 44 here has an oblong shape, so that the body 38 of the screw 34 is movable in translation within this orifice 44 in a plane parallel to the bottom wall 2 of the tank 1 which defines its oblong shape. In other words, the orifice 44 has a first longitudinal end 50 and a second end 52 which are opposite each other along the main dimension of the orifice 44, the body 38 of the screw 34 being movable in translation from the first longitudinal end 50 to the second longitudinal end 52. The first longitudinal end 50 is further from the base 4 than the second longitudinal end 52. In order that an operator of the guide device 16 can easily access the adjustment system 32 through the base 14, this base 14 has a window 53 arranged opposite the orifice 44. This window 53 is visible at figures 2 And 6 .

[0060] As mentioned previously, the second portion 20 is movable relative to the first portion 18, the slanted wall 26 sliding along the oblique wall 22. For this purpose, the adjustment means 32 is implemented; the screw 34 is thus screwed into the first partition 40 and translates from the first longitudinal end 50 of the orifice 44 to its second longitudinal end 52. In doing so, the adjustment means drives the second portion 20 in which the head 38 of the screw 34 is engaged, the second portion 20 then passing from its first position at a distance from the base 4 to its second position in which the buffer 30 is in contact with this base 4. Such a passage of the second portion 20 from its first to its second position is illustrated in figure 6 .

[0061] On this figure 6 a through opening 54 is also shown, which is arranged within the base 14 of the loading and / or unloading tower 6. The through opening 54 constitutes a means of checking correct positioning of the buffer 30 carried by the second portion 20 of the guide device 16 in contact with the base 4. As a result, the through opening 54 is arranged in the base 14 opposite an interface between the second portion 20 and the base 4, that is to say opposite a zone of the base 4 against which the buffer 30 is intended to come into abutment. The through opening 54 therefore makes it possible to ensure correct sliding of the second portion 20 relative to the first portion 18.

[0062] As a means for ensuring correct sliding of the second portion 20 relative to the first portion 18, the guide device 16 further comprises a means for guiding the second portion 20 relative to the first portion 18. This guide means more precisely comprises at least one rebate 56 which is notably visible at the figure 5 .

[0063] The rebate 56 is here integral with the first portion 18. It corresponds to an extension of this first portion 18 which extends along the oblique wall 22 to the slanted wall 26 of the second portion 20. The rebate 56 is for example a stainless steel plate pressed against internal faces of the first portion 18 and of the second portion 20, opposite both the oblique wall 22 and the slanted wall 26.

[0064] The rebate 56 forms a stop for the oblique wall 22; it is thus in sliding contact with this oblique wall 22, so as to prevent translation in a direction perpendicular to this oblique wall 22. The guide device 16 may, depending on the embodiments, have a single rebate 56 or two rebates 56. In the presence of two rebates 56, a first is arranged on the internal face of the oblique wall 22 and a second is arranged on the internal face of the slanted wall 26. In other embodiments, in the presence of two rebates 56, these are arranged on either side of the oblique walls 22 and slanted 26, so as to form a guide corridor for the slanted wall 26. In this case, there is then a rebate 56 arranged along the internal faces of the first and second portions 18, 20, and another rebate 56 along external faces of these portions 18, 20.

[0065] A method of assembling the storage tank 1, during which the loading and / or unloading tower 6 is positioned within the volume of the storage tank 1, will now be described. The installation of the loading and / or unloading tower 6 within the volume of the storage tank 1 allows the loading and / or unloading of liquefied natural gas within the storage tank 1.

[0066] The assembly method begins with a step of pre-positioning the guide device 16, during which this guide device 16 is secured to the base 14 of the loading and / or unloading tower 6. More particularly, the first portion 18 is secured by welding to the base 14. The method continues with a step of lowering the masts 12 of the loading and / or unloading tower 6, which are associated with each other via the base 14, from the cover of the storage tank 1 towards the base 4 secured to the bottom wall 2. Once the base 14 is as close as possible to the base 4, the assembly method comprises an adjustment step. During this adjustment step, the guide device 16 moves from its first position to its second position; the slanted wall 26 slides along the oblique wall 22 so that the second portion 20 translates along the first portion 18.The buffer 30 carried by the guide device 16 then comes into contact with the base 4, so as to ensure the vertical translation of the loading and / or unloading tower 6 while preventing its movement in a plane parallel to the bottom wall 2 of the storage tank 1. The positioning of the guide device 16 is verified during a control step, during which an operator ensures, through the through opening 54, that the buffer 30 is indeed in contact with the loading and / or unloading tower 6.

[0067] Notably, the lateral flank 28 of the second portion 20 has a dimension, measured along the vertical direction V, which is greater than a dimension of the buffer 30 measured along this vertical direction V. The lateral flank 28 therefore comprises, on one of its faces which is intended to be opposite or in contact with the base 4, at least one zone devoid of buffer 30. As can be seen in particular in figure 5, the lateral flank 28 here comprises a first end zone 29 and a second end zone 31 which are not covered by the buffer 30. The first end zone 29 is arranged in the vicinity of the second partition 42 of the second portion 20 while the second end zone 31 is opposite this second partition 42. The buffer 30 is carried by a central zone of the lateral flank 28, which is arranged between the first end zone 29 and the second end zone 31 in the vertical direction V. Such an arrangement of the buffer 30 on the lateral flank 28 makes it possible to improve the absorption of forces within the guide device 16, such forces being in particular concentrated on the second end zone 31 during use of the guide device 16.

[0068] The present invention thus provides a buffer support configured to facilitate the installation of the loading and / or unloading tower with which it is associated at a base of a liquefied natural gas storage tank, the mobility of a portion of the buffer support relative to another making it possible to adjust a position of the buffer support and as such to reduce the number of steps necessary for assembly between the loading and / or unloading tower and the base.

[0069] The present invention cannot, however, be limited to the means and configurations described and illustrated here and it also extends to any equivalent means and configuration as well as to any technically effective combination of such means.

Claims

1. Loading and / or unloading tower (6) configured for loading and / or unloading cryogenic fluid into a storage tank (1), comprising a guide device (16), a plurality of masts (12) and a base (14) connecting the masts (12) together, the guide device (16) being secured to the base (14) and configured to come into contact with a base (4) secured to a bottom of the storage tank (1), the guide device (16) being intended to allow the positioning of the cryogenic fluid loading and / or unloading tower (6) relative to the base (4) secured to the bottom (2) of the cryogenic fluid storage tank (1), the guide device (16) comprising a first portion (18) intended to be secured to the base (14) connecting the masts (12) of the loading and / or unloading tower (6) and a second ... portion (20) intended to be in contact with the base (4),the second portion (20) being configured to carry a buffer (30), the first portion (18) comprising at least one oblique wall (22) and the second portion (20) comprising at least one slanted wall (26), the guide device (16) comprising an adjustment means (32) configured to slide the slanted wall (26) along the oblique wall (22)., 2. Loading and / or unloading tower (6) according to claim 1, wherein the slanted wall (26) and the oblique wall (22) are parallel to a sliding direction of the second portion (20) relative to the first portion (18).

3. Loading and / or unloading tower (6) according to any one of claims 1 and 2, comprising at least one buffer (30) configured to come into contact with the base (4) during a movement of the loading and / or unloading tower (6) along its extension axis.

4. Loading and / or unloading tower (6) according to claim 3, wherein the buffer (30) is arranged on a flank (28) of the second portion (20) extending in a plane intersecting the slanted wall (26).

5. Loading and / or unloading tower (6) according to any one of claims 1 to 4, wherein the adjustment means (32) comprises at least one positioning means (34) provided with a head (36) and a body (38), one bearing on the second portion (20) and the other being engaged in the first portion (18).

6. Loading and / or unloading tower (6) according to claim 5, wherein the positioning means (34) comprises an end portion which extends through an oblong-shaped orifice (44) formed in one of the portions (18, 20), the end portion of the positioning means (34) being movable in translation within the orifice (44) in a plane defining the oblong shape of the orifice (44).

7. Loading and / or unloading tower (6) according to any one of claims 1 to 6, comprising means for guiding the second portion (20) relative to the first portion (18).

8. Loading and / or unloading tower (6) according to claim 7, wherein the guide means comprises at least one rebate (56) integral with one of the portions (18, 20) and in sliding contact with the other of the portions (18, 20), the rebate (56) extending along the oblique wall (22) or along the slanted wall (26).

9. Loading and / or unloading tower (6) according to any one of the preceding claims, in which the base (14) has a through opening (54) provided opposite the guide device (16).

10. Storage tank (1) for cryogenic fluid, comprising a loading and / or unloading tower (6) according to any one of claims 1 to 9, a bottom wall (2) and a base (4) serving to connect the loading and / or unloading tower (6) to the bottom wall (2), the guide device (16) being configured to block a movement of the loading and / or unloading tower (6) in a plane substantially parallel to the bottom wall (2) while allowing a translation of the loading and / or unloading tower (6) in a direction substantially perpendicular to the bottom wall (2).

11. Method for assembling a storage tank (1) according to claim 10, a step of lowering the loading and / or unloading tower (6) towards the base (4), comprising a step of pre-positioning the guide device (16) on the base (14), and a step of adjusting the guide device (16) during which the second portion (20) translates along the first portion (18) until the guide device (16) is in contact with the base (4).

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