REMELTING PLANT AND METHOD FOR OPERATING A REMELTING PLANT

Abstract

The invention relates to a remelting plant comprising a furnace chamber (50), which can be positioned over a crucible (60) of a melting station, an electrode rod (48), which by way of a lead-through (52) can be inserted or is inserted in the furnace chamber (50), in order to contact a consumable electrode (58), and a guide column (30), on which an electrode rod carriage (40) that is fixed-ly connected to the electrode rod (48) is guided in an axially movable manner, in order to move the electrode rod (48) in relation to the furnace chamber (50), and on which a chamber carriage (38), which is connected or can be connected to the furnace chamber (50), is guided in an axially movable manner, in order to move the furnace chamber (50). The guide column (30) is articulatedly connected at a first end to a rotary column (18) such that the guide column (30) can be inclined in re-lation to the rotary column (18) and can be rotated together with the rotary column (18) about the axis of rotation (24) of the rotary column (18). The guide column (30) has in the region of the first end a weighing device (36), which is preferably attached to the rotary column (18).

Claims

1-11. (canceled)

12. A remelting plant, comprising a furnace which can be positioned over a crucible of a melting station, an electrode rod which is insertable or is inserted into the furnace via a leadthrough, so as to contact a consumable electrode, and a guide column on which an electrode rod carriage that is fixedly connected to the electrode rod is guided in an axially movable manner, so as to move the electrode rod relative to the furnace, and on which a furnace carriage that is connectable or connected with the furnace is guided in an axially movable manner, so as to move the furnace, wherein the guide column is articulatedly connected at a first end to a rotary column such that the guide column can be tilted in relation to the rotary column and can be rotated together with the rotary column about an axis of rotation of the rotary column, wherein the guide column comprises a weighing device in the region of the first end which is attached to the rotary column.

13. The remelting plant according to claim 12, wherein the guide column is articulatedly connected to the rotary column by a ball joint.

14. The remelting plant according to claim 13, wherein the ball joint encompasses the weighing device at least sectionally, the weighing device being formed as a load cell.

15. The remelting plant according to claim 12, wherein in a non-tilted state the guide column substantially extends parallel to the rotary column and is laterally spaced from the rotary column.

16. The remelting plant according to claim 12, wherein the guide column at a free second end which is opposite to the first end is operatively connected with a drive device for tilting the guide column.

17. The remelting plant according to claim 16, wherein the drive device for tilting the guide column is articulatedly attached to the rotary column and comprises at least one drive element that contacts the guide column in the region of the free second end.

18. The remelting plant according to claim 12, wherein the lead-through is connected with the furnace via a bellows and/or is rigidly connected with and movable together with the furnace carriage.

19. The remelting plant according to claim 12, wherein the furnace comprises a gimbal by which the furnace carriage is detachably connectable or detachably connected with the furnace.

20. The remelting plant according to claim 12, wherein the electrode rod carriage and the furnace carriage each comprise a carriage drive device for axially moving the respective carriage along the guide column, wherein each carriage drive device comprises a drive spindle.

21. The remelting plant according to claim 12, which further comprises a support column that is rigidly connected or connectable with a ground, and that extends substantially parallel to the rotary column and is laterally spaced from the rotary column, wherein the rotary column at a first rotary column end is rotatably supported about the axis of rotation on the ground or a platform by an axial bearing and at a second rotary column end opposite to the first rotary column end is rotatably mounted about the axis of rotation in a radial bearing which is arranged at a bar that is rigidly connected with the support column.

22. A method for operating a remelting plant, comprising: axially moving an electrode rod carriage that is fixedly connected to an electrode rod along a guide column guiding the electrode rod carriage, so as to move the electrode rod relative to the furnace for contacting an electrode, the electrode rod being insertable or inserted in a furnace via a lead-through, and axially moving a furnace carriage that is connected or connectable with the furnace along the guide column guiding the furnace carriage so as to move the furnace, wherein the guide column at a first end is articulatedly connected to a rotary column, positioning the furnace over a crucible of a melting station by rotating the guide column together with a rotary column about an axis of rotation of the rotary column, centering the electrode that is contacted by the electrode rod in the crucible by tilting the guide column relative to the rotary column, and weighing at least the electrode by a weighing device that is arranged in the region of the first end of the guide column and attached to the rotary column.

Description

DESCRIPTION OF THE FIGURE

[0038] The present invention should further be explained by means of a schematic FIGURE which shows an embodiment example of a remelting plant.

[0039] The remelting plant shown in FIG. 1 comprises a stationary support column 10 which with its lower end is rigidly connected with a ground 12 and extends vertically upwards. At an upper end which is opposite with respect to the lower end the support column 10 comprises a horizontally arranged cross beam 14 which extends beyond the base area of the support column 10. The cross beam 14 is rigidly attached to the support column 10. At an end which faces away from the support column 10, in the cross beam 14 a radial bearing 16 is formed which encloses an upper end of a rotary column 18. Here, the upper end of the rotary column 18 is also referred to as second rotary column end.

[0040] The rotary column 18 is arranged laterally adjacent to the support column 10 and extends in vertical direction parallel to it. In the shown embodiment example, the rotary column 18 is arranged above a platform 20 and is rotatably (about an axis of rotation 24) mounted on this platform 20 at the lower end (the first rotary column end) by way of an axial bearing 22. Here, the axis of rotation 24 corresponds to the longitudinal axis of the rotary column 18 as well as the longitudinal axis of the platform 20. The platform 20 is fixedly connected to the ground 12. Directly above the axial bearing 22 a weighing device 26 in the form of a single weighing cell is attached to the rotary column 18.

[0041] A section of the weighing device 26 which is spaced in lateral direction with respect to the support column 18 is at least partially enclosed by a ball joint 28. The ball joint 28 is provided at a lower end (a first end) of a guide column 30 and thus forms an articulated connection between the rotary column 18 and the guide column 30. An upper end (second end) of the guide column 30 has the design of a free end. So, guide column 30 can be inclined about the ball joint 28 in relation to the rotary column 18. In FIG. 1 the guide column 30 is shown in a non-inclined state in which the guide column 30 extends in parallel direction with respect to the rotary column 18 and is laterally spaced from it. Furthermore, by means of the ball joint 28 it is possible to transfer a rotational movement of the rotary column 18 onto the guide column 30 so that the guide column 30 can be rotated together with the rotary column 18 about the axis of rotation 24.

[0042] For inclining the guide column 30 about the ball joint 28 and in relation to the rotary column 18, the free second end of the guide column 30 has to be deflected in a targeted manner. For this purpose, a drive device which can be actuated 32 is provided which in the embodiment example shown has the design of an X-Y drive. The drive device 32 comprises two drive elements 34, more precisely an X drive element and a Y drive element. The drive elements 34 can respectively be moved in a direction which is horizontal with respect to the drive device 32, wherein both directions preferably are perpendicular to each other. For inclining the guide column 30, the drive elements 34 are connected to a head console 36 of the guide column 30, while the drive device 32 is connected to the upper end of the rotary column 18. Thus, by moving one or both drive elements 34 the free second end of the guide column 30 can be moved so that the guide column 30 can be inclined. Since by the inclination of the guide column 30 not only the lateral distance between the second end of the guide column 30 and the upper end of the rotary column 18 changes, but also the vertical distance between them, the drive device 32 is articulatedly attached to the upper end of the rotary column 18. Furthermore, the drive elements 34 are articulatedly attached to the head console 36. Thus, the drive device 32 along with the drive elements 34 incline together with the guide column 30 so that a precise inclination of the guide column 30 by actuating the drive device 32 is guaranteed in a simple manner.

[0043] On the guide column 30 a furnace carriage 38 and an electrode rod carriage 40 are guided in a movable manner. The furnace carriage 38 is arranged below the electrode rod carriage 40, i.e. between the ball joint 28 and the electrode rod carriage 40. Both carriages 38, 40 can be moved in axial direction and/or along the longitudinal axis of the guide column 30. For this purpose, the furnace carriage 38 comprises a furnace carriage drive device 42 and the electrode rod carriage 40 comprises an electrode rod carriage drive device 44. The carriage drive devices 42, 44 can separately be actuated for being able to move both carriages 38, 40 independently of each other. The carriage drive devices 42, 44 are respectively arranged at or in a recess of the carriages 38, 40 which are assigned to them. Here, the carriage drive devices 42, 44 have the design of spindle drives, wherein their drive spindle 46 is suspended at the head console 36 of the guide column 30 and extends downwards starting from that in parallel direction with respect to the longitudinal axis of the guide column 30. This allows a particularly space-saving design of the remelting plant.

[0044] At a section of the electrode rod carriage 40 facing away from the guide column 30 an electrode rod 48 is fixedly attached to the electrode rod carriage 40 by means of a bolted or clamping connection. Therefore, the electrode rod 48 can be moved by an axial movement of the electrode rod carriage 40 together with it. The electrode rod 48 extends vertically downwards from the electrode rod carriage 40 into the direction of a furnace 50 and thus is substantially parallel with respect to the guide column 30.

[0045] The electrode rod 48 is inserted in the furnace 50 by way of a lead-through 52. Between the lead-through 52 and the furnace 50 bellows 54 are provided through which the electrode rod 48 extends. These bellows 54 guarantee a vacuum- and gas-tight insertion of the electrode rod 48 in the furnace 50. When the electrode rod 48 is moved by means of the electrode rod carriage 40, then this results in a relative movement to the furnace 50 and the lead-through 52 (as well as the bellows 54). The lead-through 52 is fixedly connected to the furnace carriage 38 by way of a rigid cross connection 56 and can be moved together with it.

[0046] The electrode rod 48 contacts and/or holds at its lower end which is spaced from the electrode rod carriage 40 an electrode 58 which is consumed during said remelting process. The electrode 58 is placed in a vacuum- and gas-tight furnace space which is formed by the furnace 50 and a crucible 60 of a melting station. The electrode 58 can be moved by means of the electrode rod carriage 40 by way of the electrode rod 48. So, the consumable electrode 58 can be repositioned for achieving a predetermined melting rate. For this purpose, the changing weight of the consumable electrode is continuously measured with the help of the weighing device 26, and the process is controlled accordingly.

[0047] The furnace 50 can be connected with a contacting section of the furnace carriage 38 which extends in the direction of the furnace 50 by means of a gimbal 62. In the state of the remelting plant which is shown in FIG. 1 the furnace 50 is already positioned or put on the crucible 60 of the melting station and forms with it the vacuum- and gas-tight furnace space in which the remelting process takes place. In the state shown the contacting section of the furnace carriage 38 is positioned in a predetermined distance below the gimbal 62 so that there is no direct connection between the furnace carriage 38 and the furnace 50. By a movement of the furnace carriage 38 in an upward direction or into a direction of the second end of the guide column 30, the contacting section of the furnace carriage 38 abuts upon the gimbal 62 so that the furnace 50 can be moved vertically by means of the furnace carriage 38. So, it is possible to lift off the furnace 50, for example after the completion of the remelting process, from the crucible 60 and to unblock it.

[0048] For the energy supply of the remelting plant a first high current cable 64 is connected to a high current source 66 and fixed at a first cable suspender 68 which is attached to the rotary column 18. A second high current cable 70 is conductively connected with the first high current cable 64 and extends between the first cable suspender 68 at the rotary column 18 and a second cable suspender 72 which is attached to the guide column 30. A third high current cable 74 is conductively connected with the second high current cable 70 and the electrode rod 48 and extends between the second cable suspender 72 at the guide column 30 and a third cable suspender 76 which is attached to the electrode rod 48. Also the electrode 58 is supplied with high current by way of the electrode rod 48.

[0049] The functioning of the remelting plant can be described as follows: starting with the starting position which is shown in FIG. 1, the remelting process is initiated and the electrode 58 is continuously consumed. For this purpose, the electrode rod carriage 40 and the electrode rod 48 held by it and the electrode 58 are positioned in the highest possible starting position in which the electrode rod carriage 40 is arranged below the second free end of the guide column 30. During that the furnace 50 is separated from the furnace carriage 38 and is placed on the crucible 60. The consumable electrode 58 is repositioned in the crucible 60 by a controlled movement of the electrode rod carriage 40 into the direction of the first end of the guide column 30. For this purpose, with the help of the weighing device 26 the changing weight of the consumable electrode is continuously measured, and the process is controlled accordingly. The prevailing friction forces between the carriages 38, 40 and the guide column 30 as well as between the electrode rod 48 and the lead-through 52 do not influence the weighing result, because all these components are carried and weighed by the weighing device 26 and the prevailing friction forces thus are only effective as internal forces in the weighed part of the remelting plant.

[0050] When the remelting process at the shown first melting station is completed, the furnace 50 and the electrode rod 48 should be moved to a further melting station. In the further melting station already a new consumable electrode has been prepared and projects upwards from the crucible of this further melting station.

[0051] At first, the electrode rod carriage 40 with the electrode rod 48 being attached to it are again moved back upwards into the starting position by means of the electrode rod carriage drive device 44. Subsequently, the furnace carriage 38 is moved upwards into the direction of the second free end of the guide column 30 by means of the furnace carriage drive device 42 so that the contacting section of the furnace carriage 38 becomes connected with the gimbal 62 of the furnace 50. Through a further lifting of the furnace carriage 38 the furnace 50 is lifted off from the crucible 60 of the first melting station. The furnace carriage 38 together with the furnace 50 which is connected with it are further axially moved upwards, until a lower end of the furnace 50, considered in vertical direction, is in a higher position than the projecting end of the new consumable electrode.

[0052] The guide column 30 together with the carriages 38, 40 which are guided on it and with the electrode rod 48 and the furnace 50 are moved by rotating of the rotary column 18 about the axis of rotation 24 from the first melting station to the further melting station. Since the furnace 50 ends vertically above the prepared electrode, it is possible to move the furnace 50 over the new electrode without colliding with it. When the electrode rod 48 is positioned above the new electrode, it can be contacted and clamped from the electrode rod 48. For this purpose, in certain embodiments, the electrode rod 48 optionally may slightly be moved downwards.

[0053] The furnace carriage 38 is moved downwards so that the furnace 50 which is positioned above the crucible of the further melting station is lowered. A short time before the furnace 50 is put on the crucible of the further melting station, the new electrode is centered in the crucible of the further melting station by actuating the drive device 32 accordingly. For centering the new electrode the drive device 32 inclines the guide column 30 with the carriages 38, 40 which are arranged on it, the carriage drive devices 42, 44 along with drive spindle 46, the electrode rod 48, the lead-through 52 along with cross connection 56 and the new electrode in the desired directions about the ball joint 26. Here, however, the furnace 50 remains vertically aligned and it is not also inclined, because the gimbal 62 formed between the furnace carriage 38 and the furnace 50 as well as the bellows 54 formed between the furnace 50 and the lead-through 52 substantially compensate the inclination.

[0054] After the centering of the new electrode in the further melting station the furnace 50 is put on the crucible of the further melting station by axial movement of the furnace carriage 38 into the direction of the first end of the guide column 30 so that the furnace 50 again forms a vacuum- and gas-tight furnace space with the crucible of the further melting station. Then, the furnace carriage 38 is moved further into the direction of the first end of the guide column 30 by a predetermined distance for detaching or separating the connection between the contacting section of the furnace carriage 38 and the gimbal 62 of the furnace 50. So, during the subsequent remelting process the weight of the furnace 50 is not measured by the weighing device 26, because the furnace 50 and the weighed components are in contact only by way of the bellows 54. The remelting process, including the lowering of the new electrode, is repeated such as described with respect to the first melting station.

LIST OF REFERENCE SIGNS

[0055] 10 support column [0056] 12 ground [0057] 14 cross beam [0058] 16 radial bearing [0059] 18 rotary column [0060] 20 platform [0061] 22 axial bearing [0062] 24 axis of rotation [0063] 26 weighing device [0064] 28 ball joint [0065] 30 guide column [0066] 32 drive device [0067] 34 drive element [0068] 36 head console [0069] 38 furnace carriage [0070] 40 electrode rod carriage [0071] 42 furnace carriage drive device [0072] 44 electrode rod carriage drive device [0073] 46 drive spindle [0074] 48 electrode rod [0075] 50 furnace [0076] 52 lead-through [0077] 54 bellows [0078] 56 cross connection [0079] 58 electrode [0080] 60 crucible [0081] 62 gimbal [0082] 64 first high current cable [0083] 66 high current source [0084] 68 first cable suspender [0085] 70 second high current cable [0086] 72 second cable suspender [0087] 74 third high current cable [0088] 76 third cable suspender