ANODE CONSTRUCTION AND METHOD FOR DEPLOYING ANODE CONSTRUCTION

Abstract

The invention relates to an anode construction comprising a frame with two or more anodes and being adapted to be used with an offshore installation for remote connection with the offshore installation through cable connections between anodes and offshore installation. The frame comprises a main part and at least one movable part mounted on the main part and adapted to be pivotable or slidable in relation to the main part, where one or more anodes are mounted in a fixed position on the main part and one or more anodes are mounted on the movable part. The main part has a bottom frame part and a top frame part and further at least two anode mounting columns between the bottom frame part and the top frame part, and where the fixed anodes are mounted on the anode mounting columns.

Claims

1. An anode construction comprising a frame with two or more anodes and being adapted to be used with an offshore installation, pipelines or other equipment for remote connection with the offshore installation through cable connection between anode construction and offshore installation, where at least one anode is mounted in a fixed position in the frame of the anode construction and where at least one anode is mounted to be movable from a transport position into a deployment position, where the frame comprises a main part and at least one movable part mounted on the main part and adapted to be pivotable or slidable in relation to the main part, where one or more anodes are mounted in a fixed position on the main part and one or more anodes are mounted on the movable part, where the main part has a bottom frame part and a top frame part and further at least two anode mounting columns between the bottom frame part and the top frame part, and where the fixed anodes are mounted on the anode mounting columns.

2. An anode construction according to claim 1, where at least one anode is a longitudinal element with an axis extending through the anode and where the axis of pivoting the pivotable frame part is essentially parallel with the axis of the anode.

3. An anode construction according to claim 1, where the at least one anode is a longitudinal element with an axis extending through the anode and where the axis of pivoting the pivotable frame part is essentially perpendicular the axis of the anode.

4. An anode construction according to claim 1, where the anode columns are mounted between the bottom frame part and the top frame part between corner columns at opposed ends of the frame construction.

5. An anode construction according to claim 1, where the anode columns are corner columns between the bottom frame part and the top frame part.

6. An anode construction according to claim 1, where the number of anodes mounted in fixed positions is at least 2 and where the number of anodes mounted to be movable is at least 2.

7. An anode assembly comprising at least two anode constructions according to claim 1, where the at least two anode constructions are mutually connected, e.g. through welding, bolting or bracket connecting or a combination of these.

8. A method for deploying a retrofit anode construction to an offshore installation, the method comprising: a. Providing an anode construction with anode configuration as defined in claim 1; b. Transporting the anode construction with the movable anodes in their transportation position; c. Moving the movable anodes to the deployment position for the anode construction; d. Positioning the anode construction on its deployment site proximal the offshore construction; e. Connecting the anodes of the anode construction to the relevant parts of the offshore construction through electrical connections.

9. An anode construction according to claim 2, where the at least one anode is a longitudinal element with an axis extending through the anode and where the axis of pivoting the pivotable frame part is essentially perpendicular the axis of the anode.

10. An anode construction according to claim 2, where the anode columns are mounted between the bottom frame part and the top frame part between corner columns at opposed ends of the frame construction.

11. An anode construction according to claim 3, where the anode columns are mounted between the bottom frame part and the top frame part between corner columns at opposed ends of the frame construction.

12. An anode construction according to claim 2, where the anode columns are corner columns between the bottom frame part and the top frame part.

13. An anode construction according to claim 3, where the anode columns are corner columns between the bottom frame part and the top frame part.

14. An anode construction according to claim 4, where the anode columns are corner columns between the bottom frame part and the top frame part.

15. An anode construction according to claim 2, where the number of anodes mounted in fixed positions is at least 2 and where the number of anodes mounted to be movable is at least 2.

16. An anode construction according to claim 3, where the number of anodes mounted in fixed positions is at least 2 and where the number of anodes mounted to be movable is at least 2.

17. An anode construction according to claim 4, where the number of anodes mounted in fixed positions is at least 2 and where the number of anodes mounted to be movable is at least 2.

18. An anode construction according to claim 5, where the number of anodes mounted in fixed positions is at least 2 and where the number of anodes mounted to be movable is at least 2.

19. An anode assembly comprising at least two anode constructions according to claim 2, where the at least two anode constructions are mutually connected, e.g. through welding, bolting or bracket connecting or a combination of these.

20. An anode assembly comprising at least two anode constructions according to claim 3, where the at least two anode constructions are mutually connected, e.g. through welding, bolting or bracket connecting or a combination of these.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 shows schematically an anode construction according to the invention in a perspective view with one side in the transport mode and the opposed side in the deployment mode;

[0033] FIG. 2 shows schematically an anode construction according to the invention in a side view with one side part in the transport mode and the other side part in the deployment mode;

[0034] FIG. 3 shows in an enlarged view the electrical connection to the anode construction;

[0035] FIG. 4 shows schematically an anode construction according to the invention in an end view with one side in the transport mode and the opposed side in the deployment mode;

[0036] FIG. 5 shows schematically and enlarged a connection part adapted for connection of two anode constructions forming a larger anode assembly; and

[0037] FIG. 6 schematically shows two anode constructions assembled to form a larger anode assembly.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0038] From FIG. 1 the anode construction 1 according to the invention appears in a perspective view. The construction comprises a frame with a rectangular bottom part 2 and a rectangular top part 3 and at four perpendicular corner posts 4 extending between the bottom part 2 and the top part 3. Between the corner posts 4 the frame defines two opposed side areas and two opposed end areas. At the end areas and between the top part and the bottom part, stationary anode carrier elements 8,9 are provided. The stationary anode carrier elements 8,9 carry six anode elements 7, three towards each side area. At each side area and connected to the bottom part 2 a pivotable side part 5 is provided, connected to the bottom part 2 through hinges 6 at each side of the pivotable side part 5. Each pivotable side part 5 carries four anode elements 10. In order to control the pivoting position chains 11 are provided between the pivotable side part 5 and the corner posts 4. This mainly serves the purpose of protecting the bottom frame part 2 from an otherwise significant momentum exerted by the pivotable side part 5 to the bottom frame part through the hinges 6.

[0039] The anode element 7,10 comprises a steel core part and an anode material comprising a sacrificial metal molded around the steel core part. The core steel part is configured with curved end areas serving the purpose of creating a distance to the frame construction when mounted on this. The distance will partly separate the anodes individually from each other and partly ensure that the anode mounted on the pivotable side parts is kept free of the sea bottom. It should be appreciated that the shape and size of the anode including the core part may vary and as such is not limited to the shape and size indicated in this example.

[0040] The anode material may be any suitable metal usable for cathodic protection. Aluminium or zinc or an alloy comprising aluminium or zinc as a main component are most often preferred but for specific purposes where other materials are more appropriate these may be used without interfering with the scope of the present invention.

[0041] From FIG. 1 it further appears that one of the pivotable side parts has been pivoted into the deployment position. The chains 11 holding the pivotable side part 5 are visible in their tightened mode holding the side part and relieving the bottom frame part 2 from the torque that would otherwise be imposed to it.

[0042] From FIG. 1 a view of a hinge joint 6 between a bottom frame part and the pivotable side further appears. The hinge as such comprises a stationary bearing part and a rotating or pivoting bearing shaft, where these parts obviously are dimensioned to carry the significant weight of the pivotable side part. A hinge is provided at each side of the pivotable side part 5, i.e. two hinges are provided for each side part.

[0043] From FIG. 2 a side view appears of the anode construction, where one of the pivotable side parts 5 has been pivoted into the deployment position and one side part 5 is still maintained in the transport position. It appears that the pivotable side part in deployment position is held in place by the holding chains 11 at each side of the pivotable side part 5.

[0044] From FIG. 3 the area A shown in FIG. 1 is shown in enlarged form. The attachment to the anode construction of the cable 14 forming the electrical connection to the construction to be protected is shown here. The attachment to the anode construction will preferably happen through a cable shoe 15 attached to threaded support (preferably welded to the anode construction) by means of a nut 16 and with one or more clamps 17 for relief of the cable 14.

[0045] From FIG. 4 an end view appears of the anode construction with the side parts 5 in the transport mode and the deployment mode respectively. It is more clear from this view that the distance between the anodes 7 being mounted in a fixed position and the anodes 10 mounted on the pivotable side parts 5 is significantly less in the transport mode than in the deployment mode. As already emphasized, the closer positioning of the anodes in the transport mode will allow for a more compact and hence more efficient transport of the anode construction that at the deployment site has a larger capacity than otherwise possible within a limited space.

[0046] The frame construction is preferably a construction adapted to be movable and transported by means of standard container handling and transportation equipment. This means that the dimensions of the frame construction advantageously correspond to standard measures of container modules, e.g. 10, 20 and 40 foot in the length and with height and width corresponding to normal standard containers. This will significantly ease the handling of such system and will provide for a cost effective and reliable transportation of such constructions. In order to achieve the use of standard handling equipment engagement openings 12 (FIG. 1) are provided at the corners of the anode construction, where the engagement means of the standard lifting and handling equipment may engage. For stacking of several anode constructions or for stacking of anode constructions together with standard freight containers there may in similar way be provided means for engaging the stacked container in order to stabilize the stacked containers by preventing possible sliding of any of the containers.

[0047] The anode construction is preferably modular, meaning that a number of base modules or anode constructions may be assembled to form larger assemblies of anode constructions as shown in FIG. 6. The connection between the base modules 1,1′ may be constituted by welding or through connection means such as brackets or simply bolts extending through both anode constructions to be assembled. A combination of two or more alternative connection means may be provided. An enlarged view of the connection part 13 adapted for the connection between the two modular anode constructions 1,1′ forming an anode assembly is shown in FIG. 5. Holes in the connection part allow for insertion of suitable holding means, such as bolts, allow for holding the two holding parts 13 together and thereby holding the anode constructions 1,1′ together.

[0048] The modular construction will provide an overall optimization of the production as the individual size of the anode assembly may be adapted to the actual needs based on a standard anode construction. The manufacturing of the anodes with a shorter length is furthermore significantly easier than longer anodes.

[0049] The number of anodes in an anode unit may vary dependent on a number of factors. The distance between the anodes is important in order to achieve the optimal protection effect. The anode material may also influence the choice of distance and further the environment of deployment may have an influence on the choice of anode material. In a complex three dimensional construction a simulation of the conditions is most often used to determine the optimal distance. The dimensions of the unit will limit the number of anodes that may be accommodated in a unit. In the unit shown in the drawings six anodes are mounted in a fixed position in the frame construction with three anodes in each of two columns, and four anodes are mounted on each pivotable side part. The number of fixed anodes in each of the rows and the pivotable side parts may be shifted to be four and three, respectively.

[0050] Deployment of an anode construction at an offshore site will normally comprise pivoting the pivotable side parts into the deployment position and successively lifting the anode construction off the vessel and lowering the anode construction into the sea until firmly resting on the seabed. In the transport position the side parts are held in position by means of bolts or other types of holding means, which are removed upon preparing the anode construction for deployment. The connection of the anode construction to the offshore construction to be protected happens after the positioning on the seabed. The electrical connection is ensured through a cable connection that is at one end attached to the offshore construction, pipelines or other equipment and at the opposed end attached to the anode construction. The attachment may be performed manually or may be performed by means of a ROV (Remote Operated Vehicle). The attachment to the offshore construction may be in the form of a clamp, which is well-known in the field of retrofitting cathodic protection.

[0051] The size of the anode construction will be defined by the designed lifetime extension required in relation to the construction, pipelines or other equipment to be protected. One way of varying the size of the anode constructions is through providing these as modular units that can be connected to form larger assemblies. It will be possible to connect such anode constructions and still maintain the general format of a standard container and as such be able to use existing infrastructure and handling equipment for the transport of the anode construction(s) to the deployment site.