Device and Method for Welding Cylindrical Sections of a Casing

Abstract

A device for welding together cylindrical sections of a casing. The device comprises a clamping ring configured to surround and attach to a section of the casing and a robot provided with a welding gun and at least one joint, wherein the robot is movably attached to the clamping ring by cooperating means. A method for welding cylindrical sections of a casing by using such a device includes the steps of a) positioning and clamping the clamping ring at the correct position, b) moving the robot along the clamping ring to the correct position for welding, c) welding the sections to each other by the welding gun of the robot, and d) releasing the clamping ring.

Claims

1-15. (canceled)

16. A device for welding together cylindrical sections of an electrode casing for a melting furnace, comprising: a clamping ring configured to surround and attach to a section of the casing; and a robot provided with a welding gun and six or more joints each defining a pivotal axis, the pivotal axes of the joints being arranged perpendicular to each other, wherein the robot is movably attached to the clamping ring by cooperating means, a camera is arranged on an arm that holds the welding gun, and the device is configured to adjust the position of the robot according to the image viewed through the camera in order to position the welding gun in a position for welding.

17. The device according to claim 16, wherein the casing has an outside and the cooperating means are configured to guide the robot around the outside of the casing along the ring.

18. The device according to claim 17, wherein the clamping ring has a circumference and the circumference is adjustable by a mechanical, hydraulic or pneumatic mechanism.

19. The device according to claim 16, wherein the clamping ring has a circumference and the circumference is adjustable by a mechanical, hydraulic or pneumatic mechanism.

20. The device according to claim 17, wherein the clamping ring comprises two or more parts connected to one another by one or more hinges.

21. The device according to claim 16, wherein the clamping ring comprises two or more parts connected to one another by one or more hinges.

22. The device according to claim 16, wherein the clamping ring extends entirely around the casing as a closed ring.

23. The device according to claim 17, wherein the clamping ring extends entirely around the casing as a closed ring.

24. The device according to claim 16, wherein the cooperating means are mechanical, pneumatic, hydraulic or magnetic counterparts arranged on the clamping ring and robot, the counterparts being configured to engage each other.

25. The device according to claim 19, wherein the cooperating means are mechanical, pneumatic, hydraulic or magnetic counterparts arranged on the clamping ring and robot, the counterparts being configured to engage each other.

26. The device according to claim 24, wherein the cooperating means comprise gear rims and a gear rim of the robot is a driving gear wheel.

27. The device according to claim 16, wherein a carriage is attached to the clamping ring via the cooperating means and the robot is attached to the carriage.

28. The device according to claim 19, wherein a carriage is attached to the clamping ring via the cooperating means and the robot is attached to the carriage.

29. The device according to claim 16, wherein one or both of the clamping ring and the robot is provided with hoisting means.

30. The device according to claim 29, wherein a distal end of the hoisting means is configured to engage a second section of the casing.

31. The device according to claim 16, wherein the electrode casing is a Soderberg casing.

32. A method of welding cylindrical sections of a casing by using the device according claim 16, comprising the steps of: a) positioning and clamping the clamping ring at a predetermined position, b) moving the robot along the clamping ring to a preferred position for welding, c) welding the cylindrical sections to each other by using the welding gun of the robot, and d) releasing the clamping ring.

33. The method according to claim 32, further comprising a step of welding a patch over any windows of the casing.

34. The method according to claim 32, further comprising the step of taking and processing pictures with the camera and repositioning one or both of the clamping ring and the robot based on the processing.

35. The method according to claim 32, wherein the device comprises hoisting means, further comprising the step of attaching the hoisting means to the casing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The invention will now be described with the help of the enclosed Figures, showing a preferred embodiment of a device according to the invention.

[0057] FIG. 1 shows a welding robot arranged and ready for assignments,

[0058] FIG. 2 shows detail of a welding robot mounted on a carriage and gear rim,

[0059] FIG. 3 shows another embodiment of a clamping ring with a carriage and robot seen from above,

[0060] FIG. 4 shows another embodiment of a clamping ring with a carriage and robot seen perspective from above, and

[0061] FIG. 5 shows details of the carriage shown in FIG. 4.

DETAILED DESCRIPTION

[0062] The different parts of the figures are not necessarily to scale in relation to each other, as the diagram is merely for illustrating the invention.

[0063] The following description of an exemplary embodiment refers to the drawing, and the following detailed description is not meant or intended to limit the invention.

[0064] In the Figures, reference number 1 refers to a melting furnace having electrodes 2 being lowered into the melt 3. The electrodes consist of electrode mass which is added from the top 4 as the electrodes 2 are lowered continuously. To hold the electrode mass cylindrical sections of steel casing 12 are added with welded connections 8 between the sections. The steel casings 12 are provided with internal ribs 5 and holes 14 for access to enable welding of the connection 8.

[0065] For welding the connection 8 a robot 6 is being used, which is arranged on a carriage 25 driven by an electromotor 26 and connected to a gear rim 9 with gear wheel and guiding means 10 on both sides of the cogging, in such a way that the carriage 25 may be driven in a circular track around the casing 12.

[0066] The robot 6 is connected to the carriage 25 through the adapter 23, and may be rotated around axis 21. The joint 27 may be rotated around axis 22 and is connected to the arm 28, which is connected through the joint 30 rotatable around axis 24 to the arm 29 and the joint 31 rotatable around axis 36. The joint 31 is rotatable around axis 35 and is connected to the welding gun 32. A camera 33 is arranged close behind the welding gun 32 and provides for photographing of the welding area, in such a way that the welding gun may be positioned correctly.

[0067] Welding of the inside of the casing may be provided through the gap/opening 14 which afterwards are closed by welding by the robot. As shown, the axis 21 is perpendicular to axes 23 and 24, axis 36 is perpendicular to axes 24 and 35

[0068] The welding gun 32 and robot 6 receive power and gas through cables and tubes 40 connected to a welding apparatus 41.

[0069] Arranging the welding robot 6 in position for welding is performed manually by means of remote control from a panel 51 which is operated by a person 50 located on a deck 7 over the melting furnace 1.

[0070] In the Figures a device is shown for welding cylindrical sections of a casing 12. The device comprises a clamping ring, shown as a gear rim 9 and a guide 10 in FIGS. 1 and 2, and as a three parted ring in FIGS. 3 and 4. In other embodiments, the ring may be divided into two more than three parts. The device further comprises a robot 6 attached to the clamping ring by cooperating means, shown as a gear rim on the clamping ring and another gear rim on the carriage 25 in FIGS. 1-3. The gear rim on the carriage is driven by a motor 26, causing the carriage to move along the clamping ring.

[0071] In the embodiment shown in FIGS. 1 and 2, cables 40 run from the robot and carriage to a welding apparatus 41 on the deck, and thus the robot can only rotate one time around the casing 12 before changing direction to return to the starting point, in order to avoid stretch on the cables. Alternatively, the welding apparatus must be moved according to the movement of the carriage.

[0072] FIGS. 3 and 4 show details of a second and third embodiment of the clamping ring 100. The ring comprises three parts 100a, 100b, 100c, wherein the parts are hinged to each other by way of two hinges 101, in such a way that the clamping ring has two ends 102. A bar 103 is arranged between the two ends 102, being fixed to one end, and attached to a tightening system 104 on the other end. In the shown embodiment the tightening system is only indicated by a circle, but it may be any suitable hydraulic, pneumatic or mechanical system configured to clamp the ring around the section, by reducing the distance between the ends of the ring.

[0073] When the ring is to be arranged around a casing section, the parts 100a, 100b and 100c are pivoted to enclose the casing 12, and the bar 103 is inserted into the tightening system 104. Then the system 104 tightens the ring by reducing the distance between the ends 102 of the ring 100 until the ring is clamped onto the casing sufficiently to carry the load of the robot 6 and/or carriage 25 while following any movement of the casing. If the ring is to be removed from the casing, the steps are repeated in reversed order.

[0074] In embodiments wherein parts of the ring can not be pivoted in relation to each other, the ring may for instance be lifted above and lowered onto the casing. Once arranged around the casing, it may be tightened as described above.

[0075] In the embodiments of the clamping ring shown in FIGS. 3 and 4, the ring has a thickness T in radial direction and a length L in axial direction, and further an upper 105 and lower 108 peripheral flange, at a distance from the inner edge 106 of the clamping ring being configured to be in contact with the casing. The flanges 106, 108 are parallel to the casing and create an upward facing shelf 107, and a downward facing self (not shown). The carriage is attached to the clamping ring by elements 110 enclosing the upper and lower peripheral flange, and wheels running along the upper and/or lower flange.

[0076] In the embodiment shown in FIG. 3, the clamping ring 100 is provided with a gear rim 9 on the peripheral flange 105, the gear rim is arranged radially, and facing inwards towards the casing. The carriage is provided with a corresponding gear wheel (not shown) engaging the gear rim 9. The gear wheel on the carriage is a driving gear wheel, and is driven by a motor (not shown).

[0077] In the embodiment shown in FIGS. 4 and 5, the carriage is provided with wheels 120 being parallel to the shelf 107, wherein the wheels engage the peripheral flange 105, and as the wheels rotate, the carriage will move along the clamping ring.

[0078] In the embodiment shown in FIG. 5, the elements 110 which attaches the carriage 25 to the flange 105/108, comprises a first plate 110a protruding from the carriage 25 towards the casing, and a second plate 110b protruding from a distal end of the first plate towards the shelf 107. Once the carriage is attached to the clamping ring, the free end of the second plate 110b is close to the shelf, and thus the two plates 110a, 110b enclose the upper 105 respectively lower 108 peripheral flange. The wheels 120 providing movement along the ring 100, is attached to the upper plate 110a, and is driven by a motor (not shown). A similar structure may be present to enclose the lower flange 108. Alternatively, only the upper flange 105 may be present, with the carriage supported by elements 110 extending around the upper flange and further supported against the outward facing surface of the clamping ring by means of a wheel or another supporting element.

[0079] In an example not shown in the Figures, the lower peripheral flange 108 may also be provided with a gear rim, or the carriage may be provided with wheels engaging the lower flange.

[0080] When the embodiments shown are to be used to weld cylindrical sections of a casing, the method comprises the following steps [0081] positioning the clamping ring 100 in relation to the windows of the casing and/or the connection between two adjacent casings sections, [0082] bringing the ends 101 of the ring 100 towards each other in order to tighten the ring, [0083] moving the carriage 25 along the ring 100, to position the robot correctly at the site of welding, the carriage being moved by powering the driving wheels on the carriage, [0084] welding the sections of the casing, and possibly the ribs 5 of the sections together, while moving the carriage along the ring, and by moving the arms 28, 29 and joints 27, 30, 31 of the robot, [0085] releasing the clamping ring from the casing by bringing the ends 101 apart from each other, in order to reposition the ring at a new welding site.

[0086] If the ring is not arranged on the casing before the method is to be used, then the ring 100 must be positioned around the casing previously to the first step.

[0087] The examples above are given to illustrate the invention, and should not be used to interpret the following claims in a limited manner. The scope of the invention is not limited by the examples given above. Modifications and amendments of the invention, being obvious to a skilled person, are also included in the scope of the invention.