Technical field

The present invention relates to a transfer device between a first installation and a second installation. The transfer device comprises at least one transfer conduit and a universal joint, thereby permitting relative movement between the first installation and the second installation.

Prior art

A number of devices are known for transferring fluid from offshore platforms to transport vessels, or alternatively from a fixed installation to a vessel, or alternatively between two vessels or barges. Stringent demands are placed on safety when conducting such transfer operations, both on account of the risk of fire and explosion and from the environmental point of view due to the risk of leakages.

In rough seas the drilling platform and transport vessel will move independently in relation to each other, and the materials in the transfer device will be subjected to severe mechanical stresses. When transferring cryogenic fluid such as LNG, which is stored and transported at temperatures below -100°C down to -164°C, there are a number of extra challenges. At these temperatures the materials in the transfer devices will not be flexible and at the same time capable of withstanding the stresses that may arise.

This has never been done before, and it is uncertain whether the prior art will cope with the stresses involved in this transfer.

The object of the present invention is to provide a transfer device that avoids the drawbacks mentioned above.

Summary of the invention

The present invention relates to a transfer device between a first installation and a second installation, characterised in that the transfer device comprises at least one transfer conduit, for example for transferring cryogenic fluid or the like, and a universal joint, where the transfer device permits relative movement between the first installation and the second installation, where the universal joint comprises

• a first joint device with a bearing that forms a first axis;

• a second joint device with a bearing that forms a second axis;

• a connector rotatably mounted in each of the joint devices about the respective axes of rotation, so that the first axis of rotation is perpendicular

to the second axis of rotation; where the transfer conduit is passed through the connector.

In a preferred embodiment the transfer device comprises a connector that forms a part of the transfer conduit.

In a preferred embodiment the first joint device is connected to a loading arm in the first installation.

In a preferred embodiment the second joint device comprises a substantially conically shaped, protruding connecting device adapted to be received in a substantially correspondingly shaped connecting device in the second installation.

In a preferred embodiment the universal joint comprises:

• the first joint device comprising two substantially parallel protruding struts, where a lead-through opening is provided in each protruding strut in such a manner that the lead-through openings in the two struts form the first axis of rotation;

• the second joint device comprising two substantially parallel protruding struts, where a lead-through opening is provided in each protruding strut in such a manner that the lead-through openings in the two struts form the second axis of rotation;

• the connector rotatably mounted in each of the joint devices about the respective axes of rotation so that the first axis of rotation is perpendicular to the second axis of rotation;

• where the transfer conduit is passed through the connectors and the universal joint.

In a preferred embodiment the transfer conduit comprises a conduit for transferring cryogenic fluid.

In a preferred embodiment the transfer conduit comprises a flexible portion before and/or after the insertion in the connector.

Detailed description

The present invention will now be described in the form of an embodiment with reference to the attached drawings, in which:

Fig. 1 illustrates a transfer device between a loading arm on a platform and a transport vessel;

Fig. 2 illustrates a first joint device in the universal joint;

Fig. 3 illustrates a second joint device in the universal joint, rotated 90 degrees about the longitudinal axis'of the loading arm;

Fig. 4 illustrates the universal joint viewed along the longitudinal axis of the loading arm, but where the diameters of the pipes are not identical; and

Fig. 5 illustrates the loading arm connected to the transport vessel.

In the chosen embodiment a transfer device according to the invention will be employed between a fixed or floating platform and a transport vessel. It should be noted that the transfer device may be employed between a number of other types of installation, for example between a tank installation and tank trucks or the like.

Fig. 1 illustrates a first installation in the form of a platform 10. The platform comprises storage tanks for LNG fluid, and the fluid has to be transferred to a second installation in the form of a transport vessel 20. Only parts of the platform and the transport vessel are shown in fig. 1. On the platform 10 is mounted a loading crane 11 that can be controlled from the platform 10. The loading crane 11 can be moved both horizontally and vertically, and can also pivot about an axis of rotation D at the platform 10.

A transfer conduit 14 transfers the fluid from the storage tanks beside or through the loading crane 11, on through the transfer device 1 according to the invention to a receiving device or coupling device 60 in the transport vessel 20. It should be noted that the transfer conduit 14 in fig. 1 comprises two parallel conduits, and three conduits for parts of its length.

The transfer device 1 according to the invention will now be described with reference to figs. 2a and 2b. Here the transfer device 1 is attached to a loading arm 12 in the loading crane 11.

The transfer device 1 comprises the above-mentioned transfer conduit 14 and a universal joint 16. The universal joint 16 comprises a first joint device 21 illustrated in fig. 2, connected to a second joint device 41 illustrated in fig. 3.

The first joint device 21 is securely connected to the loading crane 14 and comprises two substantially parallel protruding struts 22, 24. In each protruding strut 22, 24 there is provided a lead-through opening 26, 28. The lead-through openings 26, 28 in the two struts form a first axis of rotation A.

The second joint device 41 also comprises two substantially parallel protruding struts 42, 44, where in each protruding strut 42, 44 there is provided a lead-through opening 46, 48. The lead-through openings 46, 48 in the two struts form a second axis of rotation B. The second joint device 41 is securely connected to a substantially conically shaped, protruding coupling device 58, intended to be

received in and connected to the coupling device 60 in the transport vessel 20 (fig. 3).

The coupling device 60 further comprises coupling means illustrated by reference numeral 62 to enable the coupling device 58 to be locked to the coupling device 60 and consequently lock the transport vessel 20 to the platform 10.

The interconnection between the first joint device 21 and the second joint device 41 will now be described.

Through each of the lead-through openings 26, 28 connectors 51, 52 are rotatably mounted in respective struts 22, 24. Similarly, through each of the lead-through openings 46, 48 connectors 53, 54 are rotatably mounted in respective struts 42, 44. The connectors 51-54 are bent at an angle of approximately 90°. The connector 51 is connected to the connector 53, while the connector 52 is connected to the connector 54, with the result that the first axis of rotation A is perpendicular to the second axis of rotation B. It should be noted that both the axis of rotation A and the axis of rotation B are perpendicular to the longitudinal axis of the loading arm 12.

In this embodiment the transfer conduit 14 comprises a first transfer conduit 14a and a second transfer conduit 14b. The first transfer conduit 14a is passed from the loading crane 11 through the connectors 51 and 53 to a coupling box 70a. Similarly, the second transfer conduit 14b is passed from the loading crane 11 through the connectors 52 and 54 to a coupling box 70b. The coupling boxes 70a and 70b comprise connecting means (not shown) for connecting the transfer conduits 14a and 14b to the transfer conduits 64a and 64b in the transport vessel 20.

The mechanical forces generated by relative motion between the platform 10 and the vessel 20 will be absorbed by the first and second joint devices 21, 41 and the connectors 51-54. The transfer conduits 14a and 14b are passed through the universal joint 16, and will only be subjected to minimal stresses.

The above detailed description is presented particularly with the intention of illustrating and describing advantageous embodiments of the invention. The description, however, in no way limits the invention to the specific embodiments that are described in detail.

It is also possible to employ the transfer device according to the invention for transfer of electric power or data information, in which case the transfer conduit comprises a power cable or an electrical or optical data information cable.

Furthermore, it will be possible to employ only one connector in each coupling joint. This will probably result in a weaker construction, and the embodiment described above will be a preferred embodiment of the invention.

It is also conceivable, moreover, for all four connectors mentioned above to be interconnected in a hub device.

Further modifications and variations will be obvious for a person skilled in the art in the light of the above description. The scope of the invention will become evident from the following patent claims and their equivalents.