EP3317578B1 - Securing a pipe in a housing - Google Patents

Description

Technical area

The invention relates to the field of mechanical constructions used for storing and / or transporting fluids, and in particular to constructions comprising ducts to be fixed to supports, in particular in cases where the duct is arranged inside the ducts. a tank or tank and more specifically when the tank or tank is likely to be subject to significant temperature differences during its use.

Technological background

In the membrane chamber technique, the internal surfaces of a supporting structure such as the inner hull of a double-hull vessel or a land-based storage facility are lined with a multilayer structure comprising two thin alternating sealing membranes with two thermal insulation layers which serve both to limit the heat flow through the tank wall and to structurally support the waterproof membranes.

In order to maximize the operating efficiency of such a tank, it is desirable to optimize the useful volume of cargo that can be loaded into the tank and to discharge from the tank. However, the use of an unloading pump drawing the liquid to the top of the tank requires to maintain a certain height of liquid at the bottom of the tank, otherwise the suction member of the pump enters into communication with the gas phase, which defuses and / or degrades the pump. Given the particular circumstances that may arise during the operation of the tank, such as under the effect of a swell of the cargo by swell or earthquake, the necessary liquid height can hardly be minimized.

The publication JP2001108198 envisages the realization of a point recess in a bottom wall of a tank having reduced dimensions relative to said bottom wall of the tank. Such a recess constitutes a buffer tank called sump into which the pumping line opens. More particularly, the pumping line is attached to a side wall of the tank so that its lower end is inserted into the sump. The The dimensions of the sump and the insertion of the end of the pumping line into the sump thus make it possible to limit the quantity of liquid necessary for the proper functioning of the pump and to optimize the operating efficiency of the tank.

However, the lower end of the pumping line is left free in the sump. Thus, this end of the pumping line can behave as a pendulum in case of heavy swell for a tank installed in a ship or earthquake in the case of a tank housed in a land installation. In addition, this free end of the pump line can present undesirable and repetitive movements due to oscillations caused by the vibrations of the pump: Such behaviors of the free end of the pump line can cause premature wear of said pump line and / or the pump.

Similar problems are likely to arise with any pipe that may be subjected to forces, including vibratory stresses, during use. The document SU1249258A1 describes a pipeline damping support.

summary

An idea underlying the invention is to provide a pipe fixing device in a housing, for example such as a sump located in a bottom wall of a sealed and thermally insulating tank.

• un collier cylindrique monté sur l'extrémité de la canalisation,
• au moins trois bras de fixation, chaque bras de fixation comportant
  • ∘ une portion de bras proximale comportant une première extrémité montée sur le collier cylindrique, la portion de bras proximale étant mobile en rotation autour d'un premier axe de rotation parallèle à une direction génératrice du collier cylindrique, une portion de bras distale comportant une première extrémité portant un patin d'appui, le patin d'appui étant monté sur ladite première extrémité de la portion de bras distale, le patin d'appui étant mobile en rotation autour d'un second axe de rotation parallèle à la direction génératrice du collier cylindrique, le patin d'appui comportant une surface d'appui tournée à l'opposé du collier et coopérant avec une paroi du logement,

dans laquelle au moins un desdits bras de fixation comporte une glissière accouplant la portion de bras proximale à la portion de bras distale et apte à guider en translation la portion de bras distale par rapport à la portion de bras proximale le long d'un axe de déplacement perpendiculaire à la direction génératrice du collier,
un organe élastique étant accouplé à la glissière pour pouvoir appliquer une force de rappel repoussant la portion de bras distale à distance de la portion de bras proximale le long de l'axe de déplacement en réponse à une contrainte tendant à rapprocher la portion de bras distale de la portion de bras proximale.The invention provides a fluid storage installation comprising a sealed and insulating tank in which a bottom wall of the tank comprises a housing, and a loading or unloading pipe arranged in the tank, one end of the pipe being housed in the housing, the installation further comprising a fixing device for fixing the pipe in the housing, the fixing device comprising:

• a cylindrical collar mounted on the end of the pipe,
• at least three fixing arms, each fixing arm comprising
  • A proximal arm portion having a first end mounted on the cylindrical collar, the proximal arm portion being rotatable about a first axis of rotation parallel to a generative direction of the cylindrical collar, a distal arm portion having a first end bearing a bearing pad, the bearing pad being mounted on said first end of the distal arm portion, the bearing pad being rotatable about a second axis of rotation parallel to the generative direction of the cylindrical collar, the support pad having a bearing surface facing away from the collar and cooperating with a wall of the housing,

wherein at least one of said attachment arms includes a slideway coupling the proximal arm portion to the distal arm portion and adapted to translationally guide the distal arm portion relative to the proximal arm portion along an axis of displacement perpendicular to the generating direction of the collar,
an elastic member being coupled to the slideway for applying a biasing force urging the distal arm portion away from the proximal arm portion along the axis of movement in response to stress tending to bring the distal arm portion closer together of the proximal arm portion.

Thanks to these characteristics, it is possible to fix the free end of a pump line in a tank housing. Furthermore, such a fixing device does not require modification of the housing or fixing passing through a wall of said housing. In addition, such a fixing device makes it possible to fix a pipe in housings having different dimensions and / or shapes. Finally, such a device allows the elastic damping of forces between the end of the pumping line and the housing.

According to embodiments, such a fluid storage facility may include one or more of the following features.

According to one embodiment, the attachment arms extend perpendicular to the generating direction of the collar

• un tube de guidage creux fixé sur une seconde extrémité de l'une parmi la portion de bras distale et la portion de bras proximale, ledit tube de guidage se développant dans l'alignement de ladite une parmi la portion de bras distale et la portion de bras proximale,
• une tige de guidage fixée sur une seconde extrémité de l'autre parmi la portion de bras distale et la portion de bras proximale, la tige de guidage se développant dans l'alignement de ladite autre parmi la portion de bras distale et la portion de bras proximale, la tige de guidage étant montée coulissante dans le tube de guidage le long de l'axe de déplacement.

According to one embodiment, the slideway of the at least one of the attachment arms comprises:

• a hollow guide tube attached to a second end of one of the distal arm portion and the proximal arm portion, said guide tube developing in alignment with said one of the distal arm portion and the distal arm portion; proximal arm,
• a guide rod secured to a second end of the other of the distal arm portion and the proximal arm portion, the guide rod developing in alignment with said other one of the distal arm portion and the arm portion proximal, the guide rod being slidably mounted in the guide tube along the axis of displacement.

According to one embodiment, the elastic member of the at least one of the fixing arms comprises a plurality of spring washers engaged on the guide rod and bearing on the one hand on an end surface of the guide tube and, on the other hand, on an abutment surface that includes said other one of the distal arm portion and the proximal arm portion.

According to one embodiment, the elastic member of said at least one of the fixing arms comprises a first elastic element and a second elastic element connected in series between the distal portion and the proximal portion of said fixing arm, the first elastic element. having a first stiffness and the second elastic member having a second stiffness higher than the first stiffness. Thanks to these characteristics, the attachment arm can absorb different forces, one of the elastic elements thus making it possible to absorb low intensity forces, such as, for example, forces related to a vibration generated by the pump while the other element elastic allows to absorb greater forces, for example related to an earthquake or the swell of a vessel in which the tank is installed.

According to one embodiment, the cylindrical collar is made of metal, the fixing device further comprising a slip of polymer material mounted on an inner face of the cylindrical collar and bearing on the end of the pipe. Thanks to these characteristics, the collar is slidably mounted on the end of the pumping line, thus, during a contraction of the pumping line, for example linked to the introduction of GL into the tank like LNG, the collar remains mounted on the pumping line. This slip wedge can be made and fixed in different ways, for example by gluing or screwing.

According to one embodiment, the inner face of the cylindrical collar has a groove developing in the radial thickness of the cylindrical collar perpendicular to the generatrix of the cylindrical collar, the sliding wedge being accommodated in said groove and projecting radially inwardly beyond the inner face of the cylindrical collar.

According to one embodiment, the groove grows annularly around the generating direction of the cylindrical collar.

According to one embodiment, the sliding wedge is made of high density polyethylene or polytetrafluoroethylene.

• une première surface d'appui plane se développant dans un premier plan parallèle à la direction génératrice du collier cylindrique, et
• une seconde surface d'appui plane se développant dans un second plan parallèle à la direction génératrice du collier cylindrique, le premier plan et le second plan étant sécants.

The support pad can take many forms, for example with one or more bearing surfaces, for example flat or cylindrical. According to one embodiment, the support pad of at least one of the attachment arms comprises:

• a first planar bearing surface developing in a first plane parallel to the generating direction of the cylindrical collar, and
• a second planar bearing surface developing in a second plane parallel to the generating direction of the cylindrical collar, the first plane and the second plane intersecting.

According to one embodiment, the first plane and the second plane are perpendicular.

According to one embodiment, the cylindrical collar comprises a first half-cylinder and a second half-cylinder fixed together and jointly forming the cylindrical collar.

According to one embodiment, the collar comprises a shoulder projecting radially outwardly from an outer face of the cylindrical collar, each fixing arm being mounted on the shoulder.

According to one embodiment, the collar comprises lugs welded to the shoulder, the arms being directly mounted on said lugs of the shoulder. According to one embodiment, the tabs are directly welded to the cylindrical collar, the fixing arms being mounted on said tabs.

According to one embodiment, the sealed and insulating tank comprises a housing, for example at a bottom wall of the tank, said housing being open towards the inside of the tank, and an arranged loading or unloading pipe. in the tank, one end of the pipe being housed in the housing, the pipe further comprising a fixing device mentioned above, the cylindrical collar being mounted on the end of the pipe, the bearing pad of the fixing arms of said fastener being in abutment against a peripheral side wall of the housing.

According to one embodiment, the tank further comprises a pump housed in the pipe, said pump being able to load or unload a fluid respectively in or from the housing.

According to one embodiment, the tank is configured for the transport and / or storage of liquefied natural gas.

Such a tank can be part of a land storage facility, for example to store LNG or be installed in a floating structure, coastal or deep water, including a LNG tank, a floating storage and regasification unit (FSRU) , a floating production and remote storage unit (FPSO) and others.

According to one embodiment, a vessel for the transport of a cold liquid product comprises a double hull and a aforementioned tank disposed in the double hull.

According to one embodiment, the invention also provides a method for loading or unloading such a vessel, in which a cold liquid product is conveyed through isolated pipes to or from a floating or land storage facility to or from the vessel vessel.

According to one embodiment, the invention also provides a transfer system for a cold liquid product, the system comprising a aforementioned vessel, insulated pipes arranged to connect the vessel installed in the hull of the vessel to a floating storage facility. or terrestrial and a pump for driving a flow of cold liquid product through the insulated pipelines from or to the floating or land storage facility to or from the vessel vessel.

Certain aspects of the claimed invention start from the idea of fixing a pipe in a housing. Some aspects of the claimed invention start from the idea of providing a fastener that can be installed in housings with different dimensions and / or shapes. Certain aspects of the claimed invention start from the idea of providing a fixing device making it possible to limit the transmission of forces between the pipe and the housing.

Brief description of the figures

• La figure 1 représente une vue en coupe d'une paroi de fond d'une cuve étanche et thermiquement isolante comportant une structure de puisard dans laquelle est logée une extrémité d'une canalisation de pompage, un dispositif de fixation étant monté sur ladite extrémité de la canalisation de pompage ;
• La figure 2 est une vue de dessus illustrant la coopération d'une part entre la canalisation et le dispositif de fixation et, d'autre part, entre le dispositif de fixation et les parois du puisard de la figure 1 ;
• La figure 3 est une vue en perspective schématique de la canalisation de pompage de la figure 1 illustrant le dispositif de fixation de canalisation monté sur ladite canalisation de pompage ;
• La figure 4 est une vue de dessus d'un détail de la figure 3 illustrant un bras de fixation du dispositif de fixation ;
• La figure 5 est une vue en coupe selon l'axe V-V de la figure 4 illustrant le bras de fixation et le collier du dispositif de fixation ;
• La figure 6 est une vue agrandie de la zone VI de la figure 5
• La figure 7 est une représentation schématique écorchée d'une cuve de navire méthanier comportant une cuve thermiquement isolante et étanche associée à un terminal de chargement/déchargement de cette cuve.
• Les Figures 8 à 10 illustrent différentes méthodes de montage des rondelles Belleville des éléments élastiques.
• La figure 11 illustre une variante de réalisation d'un système anti-rotation bloquant la rotation du dispositif de fixation sur la canalisation de pompage.

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly in the course of the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes. with reference to the accompanying drawings.

• The figure 1 represents a sectional view of a bottom wall of a sealed and thermally insulating tank comprising a sump structure in which is housed an end of a pumping line, a fixing device being mounted on said end of the pipe of pumping;
• The figure 2 is a top view illustrating the cooperation on the one hand between the pipe and the fixing device and, on the other hand, between the fixing device and the walls of the sump of the figure 1 ;
• The figure 3 is a schematic perspective view of the pumping line of the figure 1 illustrating the pipe fastening device mounted on said pump pipe;
• The figure 4 is a top view of a detail of the figure 3 illustrating an attachment arm of the fastening device;
• The figure 5 is a sectional view along the VV axis of the figure 4 illustrating the fixing arm and the clamp of the fastening device;
• The figure 6 is an enlarged view of zone VI of the figure 5
• The figure 7 is a cutaway schematic representation of a tank of a LNG carrier having a thermally insulating and sealed tank associated with a loading / unloading terminal of this tank.
• The Figures 8 to 10 illustrate different methods of mounting Belleville washers of elastic elements.
• The figure 11 illustrates an alternative embodiment of an anti-rotation system blocking the rotation of the fixing device on the pumping line.

Detailed description of embodiments

In the description below, there will be described a fixing device that can be mounted on a pipe housed in a sump structure in the bottom wall of a storage tank and / or LNG transport. The bottom wall designates a wall, preferably generally flat, located in the bottom of the tank compared to the Earth's gravity field. The general geometry of the tank can also be of different types. Polyhedral geometries are the most common. A cylindrical, spherical or other geometry is also possible. Furthermore, such a tank can be installed in different structures such as a double hull ship, a land installation or other. Similarly, such a fixing device can be used in any wall and in any type of tank having a housing in which a pipe opens.

In the description below and in the claims, the terms "lower" and "upper" will be used to define the relative position of one element with respect to another. The term "radial" is used in the description and claims with respect to a longitudinal axis of the pumping line, a radially outwardly developing member developing radially away from the longitudinal axis of the pipeline. pumping and a radially inwardly developing member developing radially towards the longitudinal axis of the pumping line.

The figure 1 a sectional view of a bottom wall of a sealed and thermally insulating tank comprising a sump structure in which is housed an end of a pumping line 12, a fixing device being mounted on said end of the pipe of pumping.

A sealed and insulating vessel for transporting and storing LNG includes vessel walls mounted on a carrier structure 1 and having a multilayered structure superimposed in a thickness direction. Thus, each tank wall comprises a secondary thermal insulation barrier 2, a secondary waterproof membrane 3 carried by the secondary thermal insulation barrier 2, a primary thermal insulation barrier 4 carried by the secondary waterproof membrane 3 and a membrane This primary waterproof membrane 5 is intended to be in contact with a product contained in the tank, for example LNG.

The tank has side walls sealingly connected to a bottom wall 6. The bottom wall 6 comprises a sump structure locally interrupting the primary waterproof membrane 5. In a version not shown, the primary membrane 5 covers the inside of the sump.

The sump structure comprises a rigid container 7 arranged through the thickness of the bottom wall 6. The rigid container 7 has a bottom wall 8 and side walls 9. In the example shown in FIG. figure 1 , the bottom wall 8 of the rigid container 7 is located at a lower level than the secondary waterproof membrane 3 in the thickness direction of the bottom wall 6 of the tank. The side walls 9 are sealingly connected to the bottom wall 8 of the rigid container 7 so as to be closed by the bottom wall 8 of the rigid container 7. These side walls 9 extending towards the inside of the vessel from the bottom wall 8 of the rigid container 7 at least up to the primary waterproof membrane 5. An upper end of the side walls 9 forms a flange 10 sealingly bonded to the primary waterproof membrane 5. The rigid container 7 has an opening 11 located opposite the bottom wall 8 of the rigid container 7 and opening into the vessel.

Such a sump thus forms a low point of the tank occupying a reduced surface at the bottom of the tank which reduces the volume of liquid that can not be discharged during unloading of the tank. A pump line 12 has an end 13 housed in the rigid container 7. An unloading pump (not shown) is housed in the pump line 12. This pump is arranged to suck the product contained in the tank to the top of the tank, the pump comprising a suction member (not shown) located at the end 13 of the pump line 12.

In the embodiment illustrated on the figure 1 , the end 13 of the pump line 12 further comprises a filtering grill 14 limiting the risk of aspiration of residues or other undesired elements by the pump during unloading of the tank.

In order to ensure the stability of the end 13 of the pump line 12 in the rigid container 7, a fixing device 15 is installed on said end 13 of the pump line 12.

The fixing device 15 illustrated on the Figures 2 to 6 comprises a cylindrical collar 16 of complementary shape at the end 13 of the pumping line 12. This collar 16 is mounted on the end 13 of the pumping line 12. The fixing device 15 further comprises four attachment arms 17 developing radially from the mounting collar 16. Each attachment arm 17 has a telescopic structure on which is arranged a member Each fastening arm 17 may thus have a radially variable length between a retracted position and an extended position. The elastic member 18 of each attachment arm tends to deploy said attachment arm, that is to say to increase the length of said fixing arm 17. Moreover, each attachment arm 17 carries at an end opposite to the collar 16 a support pad 19 cooperating with a side wall 9 of the rigid container 7, here at the corner.

In the embodiment illustrated on the figure 2 , the rigid container is square or rectangular and has four side walls 9 developing in perpendicular planes. According to one embodiment, each side wall 9 has a width of 3m and the pump line 12 has a diameter of 600mm. Each support pad 19 has two bearing surfaces 20 developing in perpendicular planes. A variant not shown is to have an angle-shaped shoe including contiguously the two bearing surfaces 20 described above with respect to the figure 2 .

Prior to the installation of the fixing device 15, the elastic members 18 are held prestressed in order to keep the attachment arms 17 in their retracted position. In this retracted position, each attachment arm 17 has a length less than the distance between the pumping line and the area of the side wall 9 against which it must be supported. The fixing device 15 therefore has dimensions smaller than the dimensions of the rigid container 7 and can therefore be inserted easily into said rigid container 7. The prestressing of the elastic members 18 is for example of the order of 20KN to 50kN. This prestressing can advantageously be performed in the factory by suitable hydraulic means. The elastic members 18 once constrained can be locked in this position by tie rods which will be removed during the installation of the fixing device 15 in the tank.

During the installation of the fixing device 15 on the pump line 12, the collar 16 is first fixed to the lower end 13 of the pump line 12, the fixing arms 17 still being in the retracted position. The fixing device is mounted on the pump line 12 so that each attachment arm 17 develops radially from the collar 16 towards an angle of the rigid container 7 formed by two adjacent side walls 9. Once the collar 16 is mounted on the end 13 of the pump line 12, the elastic members 18 are released in order to deploy the support arms 17. The support pads 19 are then pushed and held in abutment against the side walls 9 of the rigid container 7 by the elastic member 18. More particularly, facing the figure 2 the bearing surfaces 20 are held in abutment by the elastic member 18 against a respective side wall 9 forming the angle of the rigid container 7 towards which the fixing arm carrying said bearing surfaces 20 develops. Thus, the attachment arms 17 held in this extended position by the elastic members 18 make it possible to fix the end 13 of the pump line 12 in a stable position in the rigid container 7.

Such telescopic fixing arms 17 provided with elastic members 18 make it possible to install the fixing device 15 in rigid containers 7 having various dimensions and shapes, the elastic members 18 being more or less compressed and the fixing arms 17 more or less deployed according to the dimensions and forms of rigid container 7. In addition, the elastic members 18 can absorb forces between the end 13 of the pump line 12 and the side walls 9 of the rigid container 7. In addition, such a fastening with fastening arms 17 held in compression in the rigid container 7 does not require to cross the side wall 9 of the rigid container 7 to ensure the attachment of the pumping line, thus avoiding generating bridges thermal with the outside of the tank. In addition, the resilient members 18 advantageously make it possible to compensate for the contraction of the material of the fastening arms 17, thus enabling the lower end of the pumping vessel to be securely fastened whether the tank is full of LNG at -162 ° C. or empty. and at room temperature.

Depending on the nature and intensity of the forces to be absorbed, the attachment of the pipe to the container can be envisaged only with the aid of the attachment arms 17 or also with the aid of additional support devices, as explained below. with reference to the figure 1 . In the embodiment illustrated on the figure 1 , the fixing device 15 further comprises support legs 21. Each support leg 21 develops from an attachment arm 17 towards the bottom wall 8 of the rigid container 7. Such support legs 21 provide support of the fixing device 15 in the rigid container 7 and are optional.

In the embodiment illustrated on the figure 1 , the support of the attachment arms 17 is also provided by support cables 22. A first end of these support cables 22 is anchored to a respective attachment arm 17 and a second end of these support cables 22, opposite the first end of said support cable 22, is anchored to the rim 10 of the rigid container 7. When the rigid container 7 has side walls 9 and / or a flange 10 whose strength does not guarantee the fixing of the support cables 22, said support cables 22 can be anchored directly on the primary waterproof membrane 5. The waterproof membrane primary 5 may be reinforced locally at the anchoring points of the support cables 22 by a plywood plate housed under the primary waterproof membrane 5 or any other suitable device. This support cable system advantageously allows to support a fixing device of 400kg. These support cables 22 are optional.

In an illustrated variant on the figure 3 , the support cables 22 are anchored on the pumping line 12. The support cables 22 have a clearance that makes it possible to make up the contraction of the pumping line 12 during the insertion of LNG while at the same time making it possible to retain the fixing device in a fixed position in the height of the sump. Thus, during its installation, the fixing device 15 is supported by the sole pressure of the fastening arms 17 against the side walls 9 of the rigid container 7 and, during the introduction of LNG, the thermal contraction of the element 18 no longer makes it possible to support the weight of the fixing device 15 and the pumping pipe 12 contracts so as to tension the support cables 22 in order to support the fixing device 15 without anchoring on the wall 9.

The fixing device 15 is described below in more detail with regard to the Figures 3 to 6 .

The figure 3 illustrates a schematic perspective view of the pump line 12 of the figure 1 illustrating the fixing device 15 mounted on said pump line 12.

The collar 16 is made of two half-collars 23 in the form of circular cylindrical halves preferably symmetrical. These two half-collars 23 are mounted together around the end 13 of the pump line 12 by any suitable means. Thus, each half-collar 23 may have at one of its circumferential ends a flange 24 projecting radially outwardly. The flanges 24 of the two half-collars 23 are secured for example by bolting or welding to form and fix the collar 16 on the end 13 of the pump line 12.

An anti-rotation system is provided for rotationally locking the collar 16 on the end 13 of the pump line 12. In the embodiment illustrated in FIG. figure 4 this anti-rotation system comprises a metal shim 60 welded to the pump pipe 12 and protruding radially outwardly from the pump pipe 12. This shim 60 is circumferentially interposed between the two half-collar 23, for example and as illustrated on the figure 4 , at a junction area of the flanges 24. Such a junction area of the flanges 24 forms a recess formed jointly by the crease zones of the half-collars 23 necessary for the formation of the flanges 24.

In an illustrated variant on the figure 11 , the anti-rotation system comprises two metal shims 61 welded to the pumping pipe 12 and two metal shims 62 welded to an inner face 32 of the collar 16. The metal shims 62 of the collar 16 are circumferentially interposed between the metal shims 61 of the Pumping channel 12. Each metal shim 62 of the collar cooperates with a metal shim 61 of the pumping line to form a stop blocking in rotation the collar 16 with respect to the pumping pipe 12.

A ring 25 developing in a radial plane, ie perpendicular to a longitudinal axis of the pumping pipe 12, is fixed by welding on the collar 16. This ring 25 is preferably installed on the collar 16 after said collar 16 has been fixed on the end 13 of the pump line 12 in order to stiffen the collar 16. In a variant, each half-collar 23 could comprise a prefabricated half-ring. This ring 25 projects radially outwardly from the collar 16. A plurality of tabs 26, typically one for each attachment arm 17, are fixed by welding on the ring 25. These tabs 26 project radially outwardly. . Each tab 26 comprises an upper plate 27 developing in a radial plane and a lower plate 28 developing in a radial plane parallel to the upper plate 27. In a variant not shown, the tabs 26 are directly welded to the cylindrical collar 16 or on each half-collar 23.

Each attachment arm 17 is rotatably mounted on a respective lug 26 about an axis of rotation parallel to a generating direction of the collar 16. The upper plates 27 and the lower plates 28 each have an orifice in which is mounted a pin 29 of a corresponding fixing arm 17. Each attachment arm 17 has a certain degree of deflection in rotation about the axis of rotation defined by the pin 29. For each fixing arm 17 in use, this degree of deflection is limited by the variation in length of the member elastic 18.

As visible on the figure 5 the collar 16 has an upper groove 30 and a lower groove 31 on an inner face 32. Such grooves 30 and 31 develop in the radial thickness of the collar 16. The upper groove 30 is located above the ring 25 and the lower groove 31 is located below the ring 25. These grooves 30 and 31 develop in a circular manner over all or part of the inner circumference of the collar 16. A wedge 33 is housed in each groove 30 and 31. Such a groove shim 33 is made of polymer material for example high density polyethylene or polytetrafluoroethylene. Each shim 33 is supported between the collar 26 and the end 13 of the pump line 12 on which the collar 16 is mounted. The wedges can be fixed by gluing, screwing and other suitable methods.

During a temperature change in the tank, for example during a loading of LNG at -162 ° C, the pump line 12 contracts. During this contraction, which represents a contraction of the order of 87 mm for a pumping pipe 30 m long, the fixing of the collar 16 on the pumping pipe 12 can be altered by the vertical displacement due to the thermal contraction of the pipe. Thus, the collar 16 can no longer be held stably on the pumping line 12. Such shims 33 made of polymer material allow sliding support of the collar 16 on the pumping pipe 12, the collar thus being maintained in a fixed position in the height of the sump on the pump pipe 12 by means of these wedges 33. In the case of an anti-rotation system as described above with respect to the figure 11 , each of the metal shims 61 and 62 of the anti-rotation system has a radial thickness less than the radial thickness of the shims 33 and, more particularly, less than the distance separating the internal face 32 of the pump pipe 12.

The four fixing arms 17 of the fixing device 15 being similar, a single fixing arm 17 is described below with regard to the Figures 4 to 6 .

The attachment arm 17 has a proximal arm portion 34 and a distal arm portion 35. These arm portions 34 and 35 are formed by aligned hollow rigid rods.

A first end 36 of the proximal arm portion 34 comprises a pin 29 cooperating with the tab 26. A second end 37 of the proximal arm portion 34 cooperates with a central portion 38 of the fixing arm 17 described below with respect to the figure 6 and having a telescopic structure associated with the elastic member 18.

The distal arm portion 35 has a first end 39 on which is mounted the pad 19 rotatable about an axis parallel to a generating direction of the collar 16. A second end 40 of the distal arm portion 35 is cooperating with the central portion 38 of the attachment arm 17.

The pad 19 comprises a main body 41 carrying a pin 42 housed in a hub of the first end 39 of the distal arm portion 35. A first spacer 43 develops from the main body 41 of the pad 19, the first bearing surface 20 is mounted on one end of the first spacer 43 opposite the main body 41. A second spacer 44 develops from the main body 41 of the pad 19, the second bearing surface 20 being mounted on one end of the second spacer 44 opposite to the main body 41. The first spacer 43 and the second spacer 4 develop perpendicularly to one another. Each bearing surface 20 develops in a plane perpendicular to the direction of development of the spacer on which it is mounted. The pads are made of metal to cooperate with the side walls 9 of the rigid container 7 with friction, thus providing better support of the pads 19 on the side walls 9.

In the case of a rigid container 7 made of thick plates, the pads 19 may have support surfaces 20 of square shape, round, flat or cylindrical and having characteristic dimensions for example between 5 cm and 50 cm.

In an embodiment where the container is not as rigid and has a more fragile structure, for example having a thin membrane primary waterproof membrane carried by a thermally insulating barrier, other materials than insulating foam can be installed in the primary thermally insulating barrier at the bearing areas of the pads 19. Thus, the side walls 9 of the container can be reinforced by installation of plywood or composite. In this case, the bearing surfaces of the pads can have a square shape of 20 cm side to withstand stresses of the order of 17000N or 30cm side to resist stresses of 40000N. However, in the case of a tight membrane having corrugations, the bearing surfaces 20 have dimensions limited by the distance separating two successive corrugations. The fixing device 15 thus makes it possible to install the bearing surfaces 20 out of singular areas of the membrane, for example between two corrugations in the case of a corrugated primary waterproof membrane.

The figure 6 illustrates a detail sectional view of the central portion 38 of the attachment arm 17 of the figure 5 . The central portion 38 has a distal sleeve 45 and a proximal sleeve 46. Each sleeve 45, 46 has a cylindrical shape whose diameter is smaller than the diameter of the arm portion with which it cooperates. Furthermore, each sleeve 45, 46 has an upper orifice and a lower orifice vis-à-vis one another. Similarly, the second end 37, 40 of each arm portion has an upper orifice and a lower orifice vis-à-vis one another. Each sleeve 45, 46 further comprises a shoulder 47 projecting on its periphery. The distal sleeve 45 is slidably inserted into the second end 40 of the distal arm portion 35 to the stop of said second end 40 against the shoulder 47 of the distal sleeve 45. In this abutment position, the orifices of the second 40 end of the distal arm portion 35 are vis-à-vis the orifices of the distal sleeve 45 so that a pin 58 (see figure 4 ) can be inserted into these orifices in order to lock in position the distal arm portion 35 and the central arm portion 38. The second end 37 of the proximal arm portion 34 and the proximal sleeve 46 function in a similar manner to lock in place. position the proximal arm portion 37 and the central arm portion 38.

The distal sleeve 45 comprises a cylindrical guide tube 48 coaxially developing with the distal sleeve 45 and having a hollow internal portion. The proximal sleeve 46 has a guide rod 49 developing coaxially with the proximal sleeve 46 and complementary to the hollow portion of the guide tube 48. The guide rod 49 is inserted into the hollow portion of the guide tube 48 so as to allow sliding guidance between the distal sleeve 45 and the sleeve proximal 46.

The elastic member 18 is carried by the guide rod 49. Typically, the elastic member comprises a plurality of Belleville washers 59 mounted on the guide rod 49. The Belleville washers 59 illustrated on the figure 6 are mounted in series, that is to say according to a mounting as illustrated on the figure 9 . However, these Belleville washers 59 could be mounted in parallel, as shown in figure 8 , or in a combination arrangement of serial and parallel, as shown in figure 10 . The elastic member 18 comprises in the embodiment illustrated on the figure 6 a first group of Belleville washers 59 forming a first resilient elastic member 50 and a second group of Belleville washers 59 forming a second elastic member 51 more rigid.

The guide rod 49 furthermore carries a first compression limiter 52 and a second compression limiter 53. Each compression limiter 52, 53 comprises a hollow cylindrical portion, respectively 54 and 55, with a diameter greater than the diameter of the Belleville washers. 59 closed at one of its ends by a bottom, respectively 56 and 57.

The first Belleville washer group 59 is in contact between a radially inner face of the guide tube 48 and the bottom 56 of the first compression limiter 52. The cylindrical portion 54 of the first compression limiter 52 surrounds a part of the Belleville washers 59 of said first Belleville washer set 59.

The second group of Belleville washers 59 is interposed between the bottom 56 of the first compression limiter 52 is a bottom 57 of the second compression limiter 53. The cylindrical portion 55 of the second compression limiter 53 surrounds a portion of the Belleville washers 59 of the second group of Belleville washers 59.

The first elastic element 50 has a stiffness lower than the stiffness of the second elastic element 51.

In an alternative embodiment, the central portion 38 is mounted in the other direction, the rod 49 then being on the side of the distal arm portion 35. The operation of the fixing device 15 will now be described.

When the pump of the pump line 12 is in operation, it generates vibrations of the end 13 of the pump line 12. These vibrations are transmitted to the attachment arms 17 via the collar 16. The first elastic element The flexible element 50 allows absorption of the low intensity forces caused by these vibrations of the pump in the pumping line 12. Such a flexible first resilient element 50 thus prevents the vibrations generated by the pump from being transmitted from the pumping line. to the rigid container 7 and to the primary waterproof membrane 5 via the fixing arms 17.

Conversely, during heavy stress, for example related to an earthquake in the case of a tank or under the effect of the swell in the case of a vessel installed in a ship, high intensity efforts can be transmitted to These high amplitude forces can not be absorbed by the first flexible elastic element 50 which compresses within the limit authorized by the first compression limiter 52. Typically, the Belleville washers 59 of the first group of Belleville washers 59 are compressed until the cylindrical portion 54 of the first compression limiter 52 abuts the guide tube 48, preventing further compression of the first group of Belleville washers 59. The second elastic element 51 more rigid allows then absorb these large-scale efforts. The second group of Belleville washers 59 is compressed in turn and absorbs these efforts of high amplitude.

Thus, the elastic members 18 of the attachment arms 17 make it possible to fix the end 13 of the pump line 12 while elastically absorbing forces of different intensities between the rigid container 7 and the pump line 12.

The stiffness of the elastic elements 50, 51 is advantageously selected as a function of the order of magnitude of the displacements envisaged. Thus, depending on the movements envisaged as well as the length that can be allocated to the elastic member 18 in the rigid container 7, elements can be provided. elastics having a stiffness in the range of 300 N / mm to 8000 N / mm, preferably 500 to 5000 N / mm.

Moreover, the stiffness of the elastic elements 50, 51 is preferably selected so as to withstand the worst conditions envisaged, for example in response to an earthquake in the case of a tank full of liquid and a pump line 12 also full of liquid. In an exemplary embodiment, the elastic member 18 is configured to resist an acceleration of 1g in a given direction, which can generate a reaction force of the order of 34KN that the elastic member must be able to absorb. In these cases, it can for example be installed a second elastic member 51 having a stiffness of the order of 1000N / mm to obtain displacements of between 8mm and 37mm.

The technique described above can be used to fix any type of pipe in different types of tanks, for example for a tank of an LNG tank in a land installation or in a floating structure such as a LNG tank or other.

With reference to the figure 10 , a cutaway view of a LNG tanker 70 shows a sealed and insulated tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary sealed barrier intended to be in contact with the LNG contained in the tank, a secondary sealed barrier arranged between the primary waterproof barrier and the double hull 72 of the ship, and two insulating barriers arranged respectively between the primary watertight barrier and the secondary watertight barrier and between the secondary watertight barrier and the double hull 72.

In a manner known per se, loading / unloading lines 73 arranged on the upper deck of the ship can be connected, by means of appropriate connectors, to a marine or port terminal to transfer a cargo of LNG from or to the tank 71.

The figure 10 represents an example of a marine terminal comprising a loading and unloading station 75, an underwater pipe 76 and an onshore installation 77. The loading and unloading station 75 is an off-shore fixed installation comprising a movable arm 74 and a tower 78 which supports the movable arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading / unloading pipes 73. The arm mobile 74 adjustable fits all gauges LNG carriers. A connection pipe (not shown) extends inside the tower 78. The loading and unloading station 75 enables the loading and unloading of the LNG tank 70 from or to the shore facility 77. liquefied gas storage tanks 80 and connecting lines 81 connected by the underwater line 76 to the loading or unloading station 75. The underwater line 76 allows the transfer of the liquefied gas between the loading or unloading station 75 and the onshore installation 77 over a large distance, for example 5 km, which makes it possible to keep the tanker vessel 70 at great distance from the coast during the loading and unloading operations.

In order to generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 are used, for example in the pumping pipe 12 and / or the pumps equipping the shore installation 77 and / or pumps equipping the station. loading and unloading 75.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is not limited thereto and that it comprises all the technical equivalents of the means described and their combinations if they are within the scope of the claimed invention.

The use of the verb "to include", "to understand" or "to include" and its conjugated forms does not exclude the presence of other elements or steps other than those set out in a claim. The use of the indefinite article "a" or "an" for an element or a step does not exclude, unless otherwise stated, the presence of a plurality of such elements or steps.

In the claims, any reference sign in parentheses can not be interpreted as a limitation of the claim.

Claims (15)

1. A fluid storage facility containing a fluid-tight and insulating tank, in which a bottom wall (6) of the tank contains a housing (7), and a loading or unloading pipe (12) arranged in the tank, one end (13) of the pipe being accommodated in the housing, the facility containing in addition a securing device for securing the pipe (12) in the housing (7), the securing device containing:

   - a cylindrical collar (16) mounted on the end (13) of the pipe,

   - at least three securing arms (17), each securing arm containing

   ∘ a proximal arm portion (34) containing a first end (36) mounted on the cylindrical collar, the proximal arm portion being capable of rotation about a first axis (29) of rotation parallel to a generatrix direction of the cylindrical collar,

   ∘ a distal arm portion (35) containing a first end (39) bearing a bearing pad (19), the bearing pad being mounted on said first end of the distal arm portion, the bearing pad being capable of rotation about a second axis of rotation parallel to the generatrix direction of the cylindrical collar, the bearing pad containing a bearing surface (20) facing away from the collar and collaborating with a wall (9) of the housing (7),

   in which at least one of said securing arms contains a guideway (48, 49) coupling the proximal arm portion to the distal arm portion and capable of translationally guiding the distal arm portion with respect to the proximal arm portion in an axis of displacement perpendicular to the generatrix direction of the collar,
   an elastic member (18) being coupled to the guideway so as to be able to apply a return force that pushes the distal arm portion away from the proximal arm portion in the axis of displacement in response to a stress aimed at moving the distal arm portion closer to the proximal arm portion.
2. The fluid storage facility as claimed in claim 1, in which the securing arms extend perpendicularly to the generatrix direction of the collar.
3. The fluid storage facility as claimed in one of claims 1 to 2, in which the guideway of said at least one of the securing arms contains:

   - a hollow guide tube (48) secured to a second end (40,37) of one or other of the distal arm portion and the proximal arm portion, said guide tube developing in the alignment of said one or other of the distal arm portion and the proximal arm portion,

   - a guide rod (49) secured to a second end (40,37) of the other of the distal arm portion and the proximal arm portion, the guide rod developing in the alignment of said other of the distal arm portion and the proximal arm portion, the guide rod being slidably mounted in the guide tube in the axis of displacement.
4. The fluid storage facility as claimed in claim 3, in which the elastic member of said at least one of the securing arms contains a plurality of elastic washers engaged on the guide rod and bearing, on the one hand, on an end surface of the guide tube (48) and, on the other hand, on an abutment surface that said other of the distal arm portion and the proximal arm portion contains.
5. The fluid storage facility as claimed in one of claims 1 to 4, in which the elastic member of said at least one of the securing arms contains a first elastic element (50) and a second elastic element (51) mounted in series between the distal portion and the proximal portion of said securing arm, and in which the first elastic element exhibits a first rigidity and the second elastic element exhibits a second rigidity that is higher than the first rigidity.
6. The fluid storage facility as claimed in one of claims 1 to 5, in which the cylindrical collar is made from metal, the securing device containing in addition a sliding block (33) made from a polymer material mounted on an internal face (32) of the cylindrical collar and supported on the end of the pipe.
7. The fluid storage facility as claimed in claim 6, in which the internal face of the cylindrical collar exhibits a groove (31) developing in the radial thickness of the cylindrical collar perpendicularly to the generatrix of the cylindrical collar, the sliding block (33) being accommodated in said groove and projecting radially towards the interior beyond the internal face of the cylindrical collar.
8. The fluid storage facility as claimed in claim 7, in which the groove develops in an annular manner about the generatrix direction of the cylindrical collar.
9. The fluid storage facility as claimed in one of claims 1 to 8, in which the bearing pad (19) of at least one of the securing arms contains:

   - a first plane bearing surface (20) developing in a first plane parallel to the generatrix direction of the cylindrical collar, and

   - a second plane bearing surface (20) developing in a second plane parallel to the generatrix direction of the cylindrical collar, the first plane and the second plane being secant.
10. The fluid storage facility as claimed in one of claims 1 to 9, in which the cylindrical collar contains a first half cylinder (23) and a second half cylinder (23) secured together and jointly forming the cylindrical collar.
11. The fluid storage facility as claimed in one of claims 1 to 10, in which the collar contains a shoulder (25) projecting radially towards the exterior from an external face of the cylindrical collar, each securing arm being mounted on the shoulder.
12. The fluid storage facility as claimed in one of claims 1 to 11 containing in addition a pump housed in the pipe, said pump being capable of loading or unloading a fluid respectively into or from the housing.
13. A ship (70) for the transport of a cold liquid product, the ship containing a double hull (72) and a fluid storage facility (71) as claimed in one of claims 1 to 12, in which the tank is disposed in the double hull.
14. A method of loading or unloading a ship (70) as claimed in claim 13, in which a cold liquid product is conveyed through the pipe (12) from or towards a second floating or shore-based storage facility (77) towards or from the tank of the ship (71).
15. A transfer system for a cold liquid product, the system containing a ship (70) as claimed in claim 13, the pipe (12) being so arranged as to connect the tank (71) installed in the hull of the ship to a second floating or shore-based storage facility (77) and a pump for conveying a flow of cold liquid product through the pipe (12) from or towards the second floating or shore-based storage facility towards or from the tank of the ship.

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