Remelting plant

Abstract

The present invention relates to remelting plants for metals, such as vacuum arc furnaces (vacuum arc remelting, VAR) and electro slag remelting plants (electro slag remelting, ESR), which have one or more melting locations. The plants have a uniformly low overall height and allow weighing with the highest precision. For this purpose, they are provided with a non-coaxially driven electrode rod (140) and a weighing device (230, 240) arranged laterally. The electrode is centered without generating transverse forces which have a negative influence on the plant structure and the weighing result.

Description

[0001] remelting plant

[0002] The present invention relates to remelting plants for metals, such as vacuum arc remelting (VAR) and electroslag remelting (ESR) plants, which have one or more melting points.

[0003] Technical background

[0004] Various processes and systems for remelting metals and metal alloys are known from the state of the art. These include, for example, vacuum arc furnaces (VAL) and electroslag remelting plants (ESP). They are primarily used in specialty metallurgy for remelting and refining various reactive or non-reactive metallic materials such as tool steels, nickel-based alloys, titanium, zirconium, etc. To meet the high quality requirements of the resulting materials, these systems have been used in recent decades as completely enclosed, almost always vacuum-tight, or even vacuum- and pressure-tight units in the development of remelting technology.

[0005] These types of remelting plants essentially consist of one or more—usually two—melting points, a supporting structure in the form of a portal or a cantilevered column, a vertically movable electrode rod guided by it, a water-cooled crucible (also called a mold), and a furnace vessel (also called a crucible hood), which can be designed as either a vacuum or pressure vessel. The plant can be opened and closed by means of appropriate drives, allowing the electrode to be inserted from the material to be remelted and the resulting ingot to be lifted out. The electrode inserted into the crucible is attached to the electrode rod and melted by a very high current at low voltage, causing it to drip into the crucible, thus creating an ingot with new, improved properties.As the electrode melts, it is continuously moved downwards with the electrode rod to ensure optimal distances for current flow and arc.

[0006] In DE 102016 100 372 A1, a remelting plant is described which comprises a crucible, a furnace boiler, a height-adjustable electrode rod holder for holding an electrode rod which, in the assembled state, runs coaxially through the furnace boiler and the crucible via a vacuum-tight feedthrough at the upper end of the furnace boiler, and a high-current supply.

[0007] November 7, 2025 1 / 26, which is connected to the electrode rod via a first high-current cable and to the crucible or furnace vessel via a second high-current cable. Furthermore, document DE 102016 100 372 A1 proposes that the electrode rod holder, the electrode rod, and the furnace vessel be designed to be height-adjustable. The electrode rod holder and the furnace vessel holder are each attached to a crossbeam guided between two columns of a portal. Each of the crossbeams has a spindle drive to allow independent movement. The electrode rod and the furnace vessel are arranged above a frame with a rail system on which several melting stations with crucibles are mounted so as to be alternately slidable.

[0008] The main disadvantage of the plant proposed in document DE 102016 100 372 A1 is that it lacks feedback – such as a weighing device – for controlling the melting rate. This absence of feedback in the form of a weighing device leads to various metallurgical problems in the final product.

[0009] Document EP 3 752 303 A1 describes another remelting plant and a method for operating this plant, in which an electrode is continuously melted. The remelting process is controlled by a weighing device according to the changing weight of the melting electrode. The electrode is melted in a closed chamber bounded by the crucible of a melting station and a furnace kettle of the remelting plant positioned above it. An electrode rod carriage, rigidly connected to the electrode rod, is mounted on a guide column that is pivotally mounted on a rotating column. The weighing device is located in the area of ​​the pivoted connection. The electrode, which is contacted by the electrode rod, is centered in the crucible by tilting the guide column relative to the rotating column.

[0010] Furthermore, remelting plants are known in practice in which a weighing device with several load cells is arranged on the lid of a furnace vessel. The weighing device carries a coaxially driven electrode rod that extends into the furnace vessel through a feedthrough.

[0011] The electrode rod itself is designed as a coaxially driven assembly. The electrode rod drive is positioned above the electrode rod and is designed as a threaded spindle-nut combination, allowing the electrode rod to be moved vertically into the furnace vessel like a telescopic system.

[0012] November 7, 2025 2 / 26 When preparing remelting electrodes for the systems according to all these system concepts, the electrode is not usually attached directly to the electrode rod, but rather held in place by a clamping device via an intermediate piece, generally referred to as a stub. The stub represents the non-consumable part of the electrode-stub system and is used multiple times. After the melting process is complete, it is separated from the remaining electrode fragment and welded onto a new electrode. At its upper end, the stub has a special geometry that is adapted to the corresponding geometry of the electrode rod present in the system or to its clamping device, ensuring its secure clamping to this electrode rod.

[0013] Because the electrode and stub cannot always be welded perfectly concentrically to each other, and absolute coaxiality cannot be expected when inserting the electrode-stub system into the mold, remelting systems are equipped with so-called XY adjustment mechanisms. These mechanisms allow the electrode rod and stub system to be centered in the crucible. This achieves coaxiality between the mold and the electrode, which is a prerequisite for initiating a flawless melting process.

[0014] The disadvantage of the system described in document EP 3 752 303 A1, and of other systems known from practical experience, is that the electrode is centered in the crucible by tilting the entire electrode-stud system with the electrode rod around its support point. This can lead to high lateral forces and thus undesirable distortions and elastic deformations in the supporting structure. To achieve this centering by tilting the entire electrode-stud system, the weighing device in systems with a weighing unit on the upper end of the vessel is designed as a gimbal frame. This is not only very complex in design and manufacturing, but also leads to inaccurate weighing results.Another disadvantage of these remelting plants with the weighing device and the electrode rod with the electrode rod drive on the upper end of the furnace is that, for charging the remelting plant, the furnace, along with the plant components mounted on it, must be lifted. This results in a comparatively large plant height, the sum of the heights of the electrode rod, the electrode rod drive, the weighing device, the furnace, the electrode, and the crucible. A further disadvantage of this plant design is that centering by tilting the electrode-stub system in the weighing device also generates lateral forces. These are absorbed by the cross-linkages in the weighing device itself. This creates frictional forces in the joints of the cross-linkages of the weighing device, which negatively affect the weighing result and the accuracy of the measurement.

[0015] November 7, 2025 3 / 26 sung greatly reduced.

[0016] The invention is therefore based on the objective of providing a remelting plant that enables weighing with the highest accuracy while maintaining a consistently low overall height.

[0017] In a first aspect, the present disclosure relates to a remelting plant comprising: a vertically arranged main column and a frame-shaped guide column arranged parallel to the main column with an upper transverse connection, wherein the main column and the guide column are movably connected in an upper end region; a frame arranged horizontally in front of the main column with a rail system on which one or more melting stations with crucibles are suspended, wherein the one or more melting stations with the crucibles are horizontally movable along the rail system; a lower and an upper support which are vertically guided and movable on the guide column; a furnace vessel which is detachably connected to the lower support; a non-coaxially driven electrode rod which is connected to the upper support; a weighing device arranged laterally spaced from the electrode rod which is connected to the main column;and a power supply;

[0018] In a second aspect, the present disclosure relates to a remelting plant comprising: a vertically arranged main column and a frame-shaped guide column arranged parallel to the main column with an upper transverse connection, wherein the main column and the guide column are movably connected in an upper end region; a frame arranged horizontally in front of the main column with a rail system on which one or more melting stations with crucibles are suspended, wherein the melting stations with the crucibles are horizontally movable along the rail system;

[0019] November 7, 2025 4 / 26 two vertically guided and movable brackets on the guide column, each with a cantilever; a furnace vessel detachably connected to the cantilever of the lower bracket; an electrode rod connected to the cantilever of the upper bracket; two threaded spindles suspended laterally and vertically from the upper cross member of the guide column, their associated threaded nuts being mounted in the cantilever of the furnace vessel bracket and their upper ends being connected to drives resting on the upper cross member; a threaded spindle suspended vertically in the center of the upper cross member of the guide column, its associated threaded nut being mounted in the cantilever of the electrode rod bracket and its upper end being connected to a drive resting on the upper cross member;a vacuum feedthrough at the upper end of the furnace vessel, comprising an upper sealing section and a lower flexible section, the upper sealing section enclosing the electrode rod and connected via a bridge to the cantilever of the furnace vessel support, and the lower flexible section being connected on one side to the upper sealing section and on the other side to the upper end of the furnace vessel; a power supply; and a horizontal console attached to or forming an integral part of the main column, supporting at least two load cells on which the guide column is mounted.

[0020] The "upper end region" of the main column and / or the guide column refers to the upper 40% of the total height, preferably the upper 30%, the upper 20%, the upper 10%, or the upper 5%. If the top edges of the two columns are not at the same height, the specification refers to the column with the lower top edge, which in most cases will be the guide column.

[0021] In a third aspect, the present disclosure relates to a remelting plant comprising: a vertically arranged main column and a frame-shaped guide column arranged parallel to the main column with an upper transverse connection, wherein the main column and the guide column are connected in an upper end region via a hinged rod; a frame arranged horizontally in front of the main column with a rail system,

[0022] November 7, 2025 5 / 26 on which one or more melting stations with crucibles are suspended, the melting stations with the crucibles being horizontally movable along the rail system; two vertically guided and movable supports on the guide column, each with a cantilever; a furnace vessel detachably connected to the cantilever of the lower support; an electrode rod connected to the cantilever of the upper support; two threaded spindles suspended laterally and vertically on the upper cross member of the guide column, their associated threaded nuts being mounted in the cantilever of the furnace vessel support and their upper ends being connected to drives which in turn rest on the upper cross member;a threaded spindle suspended vertically in the center of the upper cross member of the guide column, its associated threaded nut being mounted in the cantilever of the electrode rod holder and its upper end being connected to a drive which in turn rests on the upper cross member; a vacuum feedthrough at the upper end of the furnace vessel comprising an upper sealing section and a lower flexible section, the upper sealing section enclosing the electrode rod and connected via a bridge to the cantilever of the furnace vessel holder, and the lower flexible section being connected on one side to the upper sealing section and on the other side to the upper end of the furnace vessel; a power supply;and a horizontal console attached to the main column or forming an integral part of it, supporting at least two load cells on which the guide column is mounted, wherein the melting stations each comprise two carriages arranged one above the other, which carry the crucibles in a central opening and are each connected to a carriage drive by means of which they are movable horizontally on the melting stations, wherein one carriage with the carriage drive is movable parallel to the rail system and one carriage with the carriage drive is movable orthogonally to the rail system.

[0023] A remelting plant designed according to the revealed specifications has several advantages. First of all, the height of the plant does not change during operation due to the independent movement of the electrode rod and the furnace vessel along the guide column. It maintains its structural height independently.

[0024] November 7, 2025, 6 / 26 gig of the state - opening, closing, melting, loading, unloading - at. As a result, the plant permanently maintains the minimum possible construction height.

[0025] Furthermore, the electrode is centered via lateral movements of the crucible with the inserted electrode-stud system in one plane, thus preventing bending moments and transverse forces from negatively affecting the design of the system.

[0026] A further advantage of a remelting system according to the disclosure lies in the accuracy of the positioning of the electrode-stud system under the electrode rod before clamping. Clamping of the electrode-stud system is performed after centering the system under the electrode rod and takes place in a near-ideal vertical state and with coaxiality between the electrode and electrode rod. This feature of the system also minimizes the transverse forces and bending moments on the entire system structure.

[0027] In a fourth aspect, the present disclosure relates to a method for operating a remelting plant comprising the following steps:

[0028] Inserting an electrode at a loading position into a crucible of a melting station with two carriages arranged one above the other, which carry the crucible in a central opening and are each connected to a carriage drive by means of which they can be moved horizontally on the melting stations, wherein one carriage with the carriage drive can be moved parallel to a rail system and one carriage with the carriage drive can be moved orthogonally to the rail system;

[0029] Positioning the melting station at an operating position below a furnace boiler through which an electrode rod runs, by horizontal movement along the rail system;

[0030] Centering the electrode under the electrode rod by moving the carriages with the crucible using the carriage drives and clamping the centered electrode to the electrode rod;

[0031] The furnace vessel is placed on the crucible by lowering a lower support on a guide column, wherein the lower support is lowered further after the furnace vessel is placed on the crucible, so that a detachable connection between the furnace vessel and the lower support is released, whereby a flexible area of ​​a vacuum feedthrough is compressed, so that the guide column including the parts suspended from it and the clamped electrode bears its weight onto load cells;

[0032] November 7, 2025 7 / 26 Performing the remelting process by supplying current to the electrode and the crucible while lowering an upper support on the guide column, using the measured values ​​of the load cells to control the lowering process.

[0033] In a fifth aspect, the present disclosure relates to a method for operating a remelting plant comprising the following steps:

[0034] Inserting an electrode with a stub at a loading position into a crucible of a melting station with two carriages arranged one above the other, which carry the crucible in a central opening and are each connected to a carriage drive by means of which they can be moved horizontally on the melting stations, wherein one carriage with the carriage drive can be moved parallel to the rail system and one carriage with the carriage drive can be moved orthogonally to the rail system;

[0035] Positioning the melting station by horizontal movement along the rail system at an operating position below the furnace boiler, through which the electrode rod runs;

[0036] Centering the electrode with stub under the electrode rod by moving the carriages with the crucible using the carriage drives and clamping the centered electrode with the stub to the electrode rod;

[0037] The furnace vessel is placed on the crucible by lowering the lower support with the arm on the guide column by means of the threaded spindles, wherein the support with the arm is lowered further after the furnace vessel is placed on the crucible, so that the detachable connection between the furnace vessel and the arm is released, whereby the flexible area of ​​the vacuum feedthrough is compressed by the bridge, so that the lower support with the arm, the threaded nuts and the bridge together with the upper support with the arm and the threaded nut as well as the drives, the threaded spindles, the threaded spindle, the upper sealing area of ​​the vacuum feedthrough and the electrode rod including the clamped electrode with stub on the guide column and their weight is jointly placed on the load cells;

[0038] The remelting process is carried out by supplying current to the electrode and the crucible while lowering the upper support with the arm on the guide column by means of the threaded spindle, whereby the measured values ​​of the load cells are used to control the lowering process.

[0039] November 7, 2025 8 / 26 Brief description of the drawings

[0040] Figure 1 shows a perspective view of a variant embodiment of the remelting plant according to the invention.

[0041] Detailed description of the revelation

[0042] The detailed description of the disclosure refers to the aspects mentioned in the summary of the disclosure. All features of the embodiments described below can relate to both the remelting plant and the process for its operation.

[0043] A remelting plant as disclosed comprises a vertically arranged main column and a frame-shaped guide column mounted parallel to the main column, movably connected at an upper end. The main column can, for example, have a round, oval, or rectangular base. The guide column has an upper cross-connection. This upper cross-connection can correspond to the upper side of the frame, connecting the vertical sides. Depending on the design and arrangement of the other components of the plant, it can either be the length of the distance between the vertical sides, resulting in a simple rectangular frame, or it can be longer, extending laterally beyond the rectangular frame.

[0044] The latter option can simplify the design of the other components.

[0045] The movable connection between the main column and the guide column allows the two columns to move relative to each other, thus accommodating the movement required by the weighing device. Depending on the weighing device, this connection can be articulated, for example, using a chain or wire rope. Alternatively, sufficiently flexible rigid connections are also possible, such as those using thin rods or flat bars that can accommodate the small amount of movement required by load cells.

[0046] Furthermore, a remelting plant according to the disclosure comprises a frame arranged horizontally in front of the main column with a rail system on its upper side, on which one or more melting stations with crucibles are suspended, wherein the one or more melting stations with the crucibles are movable horizontally along the rail system.

[0047] The length of the rail system is dimensioned so that the melting stations can be alternately-

[0048] November 7, 2025 9 / 26 The melting stations must be movable between a loading position and an operating position, i.e., at least n + 1 melting station widths for n melting stations. For n > 2, it must be taken into account that correspondingly more "free track" is required on both sides of the operating position to be able to position all melting stations there, unless another possibility for changing the sequence of the melting stations on the rail system is provided.

[0049] The guide column is aligned with the main column and the frame such that the plane of its frame is parallel to a side of the frame on which a rail is mounted and parallel to an edge of a main column with a rectangular base or parallel to a tangent to the round or oval base of a main column, which in turn is parallel to the side of the frame.

[0050] Furthermore, a remelting plant according to the disclosure comprises a lower and an upper support, which are guided vertically on the guide column and are movable. The vertically movable supports are guided on both sides by the two vertical frame sides of the guide column. The movable supports can, in particular, each consist of two individual parts comprising the frame parts, which are connected to each other.

[0051] Furthermore, a remelting plant according to the disclosure comprises a furnace vessel detachably connected to the lower support and a non-coaxially driven electrode rod connected to the upper support.

[0052] Finally, a remelting plant as disclosed comprises a weighing device arranged laterally spaced from the electrode rod, which is connected to the main column, and a power supply.

[0053] The power supply can be designed in the usual way to provide a very high current at low voltage.

[0054] In some design variations, the power supply can be connected to the electrode rod and the upper end of the furnace boiler via high-current lines.

[0055] In various configurations of the remelting plant, the lower and upper supports can each be equipped with a cantilever. These cantilevers can extend from the vertically movable supports towards the frame positioned horizontally in front of the main column. If the movable supports each consist of two parts, these can be connected by the cantilevers.

[0056] November 7, 2025 10 / 26 In this description, the term "cantilever" does not exclusively refer to the part projecting from the brackets, but also to any connection between or on them. For example, the cantilever could consist of a continuous plate connecting the bracket, which is made up of two separate parts, or of a projecting U-shaped section and a crossbeam spaced apart from it. In any case, the design must be chosen so that sufficient clearance remains for the drives and the range of motion is not restricted. Furthermore, the cantilevers do not necessarily have to be located on the top of the brackets, but could also be located on the underside or somewhere in between, and could even differ between the two brackets. However, positioning them on the top of both brackets offers the advantage of the lowest system height for the same stroke.

[0057] In various configurations of the remelting plant, the furnace vessel can be detachably connected to the cantilever of the lower support and / or the electrode rod can be connected to the cantilever of the upper support. Connecting the furnace vessel and the electrode rod via the cantilevers allows for a greater distance from the guide column without requiring corresponding protruding parts on the column itself, which would then contribute to the load-bearing capacity. In principle, the supports themselves could also be equipped with such protruding supports. However, in many cases, it can be advantageous to accomplish this task with the cantilevers, which can then also connect the individual components of the supports, resulting in a compact and stable design.

[0058] In various configurations of the remelting plant, the remelting plant may also include a vertical drive for the support of the furnace boiler and / or a vertical drive for the support of the electrode rod.

[0059] In various embodiments of the remelting plant, the vertical drive of the furnace boiler support can comprise two threaded spindles, each of which is laterally suspended vertically on the upper cross-connection of the guide column, with associated threaded nuts each being mounted in the cantilever of the furnace boiler support and their upper ends being connected to drives which in turn rest on the upper cross-connection, and / or the vertical drive of the electrode rod support can comprise a threaded spindle which is centrally suspended vertically on the upper cross-connection of the guide column, with an associated threaded nut being mounted in the cantilever of the electrode rod support and its upper end being connected to a drive which in turn rests on the upper cross-connection.

[0060] This enables a very efficient and compact drive design that is prone to few malfunctions.

[0061] November 7, 2025 11 / 26 [The following appears to be unrelated and possibly a separate document fragment:] [The following appears to be a separate document fragment:] [The following appears to be a separate document fragment:] [The following appears to be a separate document fragment:] [The following appears to be a separate document fragment:] [The following appears to be a separate document fragment:] [The following appears to be a separate document fragment:] [The following appears to be a separate document fragment:] ] ...The drives must be controlled synchronously to prevent the bracket from tilting.

[0062] In the second variant of the cross-connection, which is flush with the frame, the threaded spindles are suspended parallel to the vertical frame members of the guide column on its inner side, and the receptacles for the threaded nuts project inwards in the arm. In this variant, the arm must be designed so that it does not obstruct the threaded spindles, for example, by providing suitable holes for their passage.

[0063] For the electrode rod drive, a threaded spindle is suspended vertically in the center of the upper cross member of the guide column, parallel to the threaded spindles. The corresponding threaded nut of this spindle is mounted in the arm of the electrode rod holder. As with the suspension of the furnace boiler, its upper end is connected to a drive mechanism, which also rests on the upper cross member. The electrode rod can then be raised and lowered on the arm of the holder via the drive mechanism of the threaded spindle.

[0064] In various embodiments of the remelting plant, the remelting plant can further include a vacuum feedthrough at an upper end of the furnace vessel, which comprises an upper sealing area and a lower flexible area, wherein the upper sealing area encloses the electrode rod and is connected via a bridge to the cantilever of the furnace vessel support or to the support of the furnace vessel, and the lower flexible area is connected on one side to the upper sealing area and on the other side to the upper end of the furnace vessel.

[0065] The upper sealing section encloses the electrode rod and allows it to slide within it in a vacuum-tight manner, thus enabling electrode tracking. It can also be connected via a bridge to the bracket's arm or directly to the furnace boiler's mounting.

[0066] November 7, 2025 12 / 26 den. Thus, even after the connection between the furnace boiler and the bracket or its extension is released, a connection remains between the electrode rod passage and the bracket of the furnace boiler, which keeps the position of the electrode rod stable even after the furnace boiler is unhooked.

[0067] In some design variations, the lower flexible section of the vacuum feedthrough can be a bellows. Compared to a compressible or elastic material, a bellows offers a longer service life and more even force distribution. Furthermore, a bellows can be made of metal, eliminating the need for additional cooling, which might be necessary when using elastomers due to temperature stress.

[0068] In various configurations of the remelting plant, the plant can also include a horizontal console that is attached to the main column or is an integral part of it. The console can therefore be either a platform firmly connected to the guide column or a projection machined into it.

[0069] In various configurations of the remelting plant, the weighing device can comprise at least two load cells on which the guide column is mounted, and optionally be supported by the horizontal console.

[0070] In this embodiment, the guide column is mounted on load cells and optionally rests on the console. This allows the weight of the guide column and all its suspended components to be continuously determined. In particular, a closed system is created at the weighing device, within which the electrode rod can move without causing a change in the load on the weighing device.

[0071] In some design variants of the remelting plant, the main column and the guide column can be movably connected in the upper end area via a connecting rod.

[0072] In various configurations of the remelting plant, the melting stations can each comprise two carriages arranged one above the other. These carriages support the crucibles in a central opening and are each connected to a carriage drive, allowing them to be moved horizontally on the melting stations. One carriage with its drive can move parallel to the rail system, while the other can move orthogonally to the rail system. This provides a particularly simple and very precise XY displacement for centering the electrode in the crucible. This is especially true if the carriage drives are not simply geared motors with driven wheels, but rather spindle lifting elements (electric cylinders) that can be controlled much more precisely.

[0073] Since the data is conducted on November 7, 2025, 13 / 26, an even higher positional accuracy can be achieved.

[0074] This allows the melting stations to be moved along the rail system, using their own drive, from the loading position to the operating position beneath the furnace vessel. The crucible, suspended in a recess in the upper carriage and extending through the lower carriage and the melting station, can then be moved in the X and Y directions via the carriage drives to fine-tune the electrode's centering before clamping it to the electrode rod. The three holes for the crucibles increase in size from top to bottom. In the upper carriage, they are just large enough for the crucibles to pass through and rest with their flanges on the edge. In the lower carriage and the melting station, the diameter is slightly larger to provide the crucible with sufficient movement for the centering adjustment.Finally, the furnace kettle is placed with its flange onto the flange of the crucible, thus hermetically sealing it.

[0075] In alternative configurations, the aforementioned drive for the melting stations can also simultaneously serve as a positioning drive in the X-direction for movement along the rail system, thus replacing the single positioning carriage and its drive unit. Depending on the drive design, it may be advantageous to incorporate a two- or multi-stage gearbox to provide gear ratios tailored to the specific tasks. This variant saves on design costs but does not achieve the same positioning accuracy as the previously described variant with two carriages. Therefore, it is necessary to weigh which aspect is more important for the specific system design.

[0076] In various configurations, the first carriage can be positioned below or above the second carriage. The centering result is unaffected by which carriage is responsible for the X and Y axes, respectively.

[0077] In various configurations, the remelting plant can comprise at least two melting stations or two melting stations. In very confined spaces, the remelting plant can also be operated with only one melting station. However, it is more advantageous to use at least two melting stations, as the remelted block can then be removed from one and a new electrode inserted while the other is in the melting process. Since more than two melting stations also result in correspondingly greater space requirements and construction costs, the additional expense is only worthwhile under certain conditions. Therefore, exactly two melting stations are the preferred option in many cases.

[0078] November 7, 2025 14 / 26 ante.

[0079] In some design variations, the main column can be anchored in a foundation. Anchoring in a foundation provides greater stability than simply screwing the column onto a base plate and allows for better force transfer into the ground.

[0080] In some design variations, the main column can be directly connected to the frame and the rail system. Besides saving space, this direct connection between the main column and the frame creates a strong, integrated unit for the entire system.

[0081] A disclosed method for operating a remelting plant, in particular a disclosed remelting plant, comprises as a first step the insertion of an electrode at the loading position into a crucible of the melting station with two carriages arranged one above the other, which carry the crucible in a central opening and are each connected to a carriage drive by means of which they can be moved horizontally on the melting stations, wherein one carriage with the carriage drive can be moved parallel to the rail system and one carriage with the carriage drive can be moved orthogonally to the rail system.

[0082] The electrode can be designed for direct clamping or equipped with a stub for clamping to the electrode rod. The loading position is positioned far enough away from the rest of the remelting plant or its operating position to allow unobstructed access to the crucible from above, for example, to insert the electrode with the stub using a loading crane.

[0083] The second step involves positioning the melting station at its operating position below the furnace vessel, through which the electrode rod runs, by moving it horizontally along the rail system. If the remelting plant is operated with more than one melting station, it may first be necessary to move a melting station that is still in its operating position below the furnace vessel to a different loading position.

[0084] The third step involves centering the electrode under the electrode rod by repositioning the carriages with the crucible using the carriage drives and clamping the centered electrode to the electrode rod. Depending on the clamping mechanism used, this is done either directly or via a stub welded to the upper end of the electrode, with the electrode-stub combination being the more common option.

[0085] The fourth step involves placing the furnace kettle onto the crucible by lowering the lower support on the guide column, whereby the lower support, after the kettle is in place,

[0086] November 7, 2025 15 / 26 The furnace vessel is lowered so much further on the crucible that the detachable connection between the furnace vessel and the lower support is released, compressing the flexible area of ​​the vacuum feedthrough so that the guide column, including the parts hanging from it and the clamped electrode, together bears the weight onto load cells.

[0087] The lower support can be designed with or without a boom. To lower the lower support, with or without a boom, along the guide column, the corresponding vertical drive is activated. This is achieved, for example, by means of the threaded spindles, for which the corresponding drives of the threaded spindles are activated. The detachable connection between the furnace vessel and the lower support can also be made via the boom. Depending on the design of the connection, the flexible section of the vacuum feedthrough is slightly compressed when lowered from the bridge, the boom, or the lower support.In the case of a remelting plant described above, the lower support with the boom, the threaded nuts and the bridge are suspended together with the upper support with the boom and the threaded nut, as well as the drives, the threaded spindles of the furnace boiler, the threaded spindle of the electrode rod, the upper sealing area of ​​the vacuum feedthrough and the electrode rod including the clamped electrode with stub on the guide column, and their weight rests jointly on the load cells.

[0088] The detachable connection is therefore designed so that it can be released by a vertical displacement of at most the maximum possible compression path of the flexible section of the vacuum feedthrough. This can be achieved, for example, by attaching a U-shaped groove or hook structure to both the boom or lower support and the furnace vessel, with their open sides interlocking. Another possibility is an eyelet-bolt combination with a bolt projecting into the eyelet. However, other holding mechanisms with a corresponding property, familiar to those skilled in the art, can also be used.

[0089] The fifth step involves carrying out the remelting process by supplying current to the electrode and the crucible while lowering the upper support on the guide column, using the measured values ​​of the load cells to control the lowering process.

[0090] As the molten electrode drips into the crucible, the weight supported by the load cells changes during the melting process. The load cell readings are used to control the lowering process of the upper holder, with or without a cantilever on the guide column, for example, by means of the threaded spindle, to adjust the electrode position during this process. The resulting vertical movement of the electrode rod in the vacuum-

[0091] November 7, 2025 16 / 26 The frictional forces generated during the reconfiguration remain within the closed system of the guide column and therefore do not affect the weighing result.

[0092] Example

[0093] The following description of an example is given with reference to Figure 1.

[0094] The remelting plant shown in the disclosure comprises a vertically arranged main column (10) and a frame-shaped guide column (20) mounted parallel to the main column (10) with an upper transverse connection (25). The main column (10) and the guide column (20) are connected at an upper end by a connecting rod (250). The main column (10) is anchored in a foundation.

[0095] The upper cross connection (25) of the frame of the guide column (20) has a greater length than the distance between the vertical sides and therefore projects laterally beyond the rectangular frame.

[0096] In front of the main column (10) is a horizontally arranged frame (30) with a rail system (40) on its upper side, on which two melting stations (50, 60) with crucibles (70, 80) are suspended, the melting stations (50, 60) with the crucibles (70, 80) being horizontally movable along the rail system (40). The main column (10) is directly connected to the frame (30) and the rail system (40).

[0097] Furthermore, two vertically guided and movable brackets (90, 100), each with a boom (110, 120), are attached to the guide column (20). The vertically movable brackets (90, 100) are guided on both sides by the two vertical frame sides of the guide column (20), while the booms (110, 120) extend from them towards the frame (30). The movable brackets (90, 100) consist of two individual parts comprising the frame sections, which are connected by the booms (110, 120).

[0098] A furnace boiler (130) is detachably connected to the arm (120) of the lower support (100) and an electrode rod (140) is connected to the arm (110) of the upper support (90).

[0099] Two threaded spindles (150) are vertically suspended laterally from the upper cross member (25) of the guide column (20), which projects beyond its width. The threaded spindles (150) are suspended parallel to the vertical frame members of the guide column (20) on its outer side. The corresponding threaded nuts (155) are mounted in the arm (120) of the support (100) of the furnace boiler (130), which has corresponding laterally projecting receptacles for this purpose.

[0100] 7 November 2025 17 / 26 At the top, the two threaded spindles (150) are connected at their ends to the drives (156), which in turn rest on the upper cross connection (25).

[0101] Furthermore, the threaded spindle (160) is suspended vertically at its center on the upper cross-connection (25) of the guide column (20), parallel to the threaded spindles (150), and its associated threaded nut (165) is mounted in the arm (110) of the holder (90) of the electrode rod (140). As with the suspension of the furnace boiler (130), its upper end is connected to a drive (166), which also rests on the upper cross-connection (25).

[0102] The outriggers (110, 120) each consist of a projecting U-shaped section and a crossbeam spaced apart from it, which connect the two-part brackets (90, 100). They are arranged on the top of the brackets (90, 100).

[0103] Furthermore, the vacuum feedthrough (170) for the electrode rod (140) is attached to the upper end (135) of the furnace vessel. It comprises the upper sealing section (172), which encloses the electrode rod (140) and is connected via the bridge (180) to the arm (120) of the support (100) of the furnace vessel (130). The vacuum feedthrough (170) also includes the lower flexible section (175), which is connected on one side to the upper sealing section (172) and on the other side to the upper end (135) of the furnace vessel. Here, it is designed as a metal bellows.

[0104] Furthermore, the remelting plant has a power supply (190) via which high current lines (200, 210) are connected to the electrode rod (140) and the upper end of the furnace boiler (135).

[0105] Finally, the remelting plant includes a horizontal console (220) which is designed as an integral part of the main column (10) and supports two load cells (230, 240) on which the guide column (20) is mounted.

[0106] The remelting plant comprises two melting stations (50, 60). Melting station (50) is shown in the loading position, melting station (60) in the operating position. Each melting station (50, 60) includes two carriages (55, 56, 65, 66) arranged one above the other, which carry the crucibles (70, 80) in a central opening and are each connected to a carriage drive (57, 58, 67, 68) by means of which they can be moved horizontally on the melting stations (50, 60), with one carriage (55, 65) being movable parallel to the rail system (40) by means of the carriage drive (57, 67) and one carriage (56, 66) being movable orthogonally to the rail system (40) by means of the carriage drive (58, 68). In Figure 1, the first car (55, 65) is arranged below the second car (56, 66).

[0107] 7 November 2025 18 / 26 For the process of moving the melting stations (50, 60) on the rail system (40) from the loading position to the operating position under the furnace boiler (130) to be placed, these are equipped with their own drive (not shown in Figure 1).

[0108] November 7, 2025 19 / 26 Reference number

[0109] 10 Main column 150, 160 Threaded spindle

[0110] 20 Guide column 155, 165 Threaded nut

[0111] 25 Cross connection 156, 166 Drive

[0112] 30 frames 170 vacuum feedthrough

[0113] 40 rail system 172 sealing area

[0114] 50, 60 melting station 175 flexible area

[0115] 55, 56, Car 180 Bridge

[0116] 65, 66

[0117] 57, 58, Car drive 190 Power supply

[0118] 67, 68

[0119] 70, 80 crucibles 200, 210 high-current line

[0120] 90, 100 bracket 220 console

[0121] 110, 120 boom 230, 240 load cell

[0122] 130 Oven boilers 250 Joint rod

[0123] 135 Oven boiler end

[0124] 140 electrode rods

[0125] November 7, 2025 20 / 26

Claims

Claims 1. Remelting plant comprising: a vertically arranged main column (10) and a frame-shaped guide column (20) arranged parallel to the main column (10) with an upper transverse connection (25), wherein the main column (10) and the guide column (20) are movably connected at an upper end region; a frame (30) arranged horizontally in front of the main column (10) with a rail system (40) on which one or more melting stations (50, 60) with crucibles (70, 80) are suspended, wherein the one or more melting stations (50, 60) with the crucibles (70, 80) are horizontally movable along the rail system (40); a lower and an upper support (90, 100) which are vertically guided and movable on the guide column (20); a furnace kettle (130) which is detachably connected to the lower support (100); a non-coaxially driven electrode rod (140) connected to the upper support (90);a weighing device arranged laterally spaced from the electrode rod (140), which is connected to the main column (10); and a power supply (190).; 2. Remelting plant according to claim 1, wherein the lower and upper supports (90, 100) are each provided with a cantilever (110, 120).

3. Remelting plant according to claim 2, wherein the furnace boiler (130) is detachably connected to the arm (120) of the lower support (100) and / or the electrode rod (140) is connected to the arm (110) of the upper support (90).

4. Remelting plant according to one of the preceding claims, further comprising: a vertical drive of the support (100) of the furnace boiler (130); and / or a vertical drive of the support (90) of the electrode rod (140). November 7, 2025 21 / 26 5. Remelting plant according to claim 4, wherein the vertical drive of the support (100) of the furnace boiler (130) comprises two threaded spindles (150) which are each laterally suspended vertically on the upper transverse connection (25) of the guide column (20), wherein associated threaded nuts (155) are each mounted in the cantilever (120) of the support (100) of the furnace boiler (130) and their upper ends are connected to drives (156) which in turn rest on the upper transverse connection (25); and / or the vertical drive of the holder (90) of the electrode rod (140) comprises a threaded spindle (160) which is suspended vertically in the center of the upper cross connection (25) of the guide column (20), wherein an associated threaded nut (165) is mounted in the arm (110) of the holder (90) of the electrode rod (140) and its upper end is connected to a drive (166) which in turn rests on the upper cross connection (25).

6. Remelting plant according to one of the preceding claims, further comprising a vacuum feedthrough (170) at an upper furnace end (135) comprising an upper sealing area (172) and a lower flexible area (175), wherein the upper sealing area (172) surrounds the electrode rod (140) and is connected via a bridge (180) to the cantilever (120) of the support (100) of the furnace (130) or to the support (100) of the furnace (130), and the lower flexible area (175) is connected on one side to the upper sealing area (172) and on the other side to the upper furnace end (135).

7. Remelting plant according to one of the preceding claims, further comprising a horizontal console (220) which is attached to the main column (10) or is an integral part of it.

8. Remelting plant according to claim 7, wherein the weighing device comprises at least two load cells (230, 240) on which the guide column (20) is mounted and is optionally supported by the horizontal console (220).

9. Remelting plant according to one of the preceding claims, wherein the main column (10) and the guide column (20) are movably connected in the upper end region via a connecting rod (250). November 7, 2025 22 / 26 10. Remelting plant according to one of the preceding claims, wherein the melting stations (50, 60) each comprise two carriages (55, 56, 65, 66) arranged one above the other, which carry the crucibles (70, 80) in a central opening and are each connected to a carriage drive (57, 58, 67, 68) by means of which they are movable horizontally on the melting stations (50, 60), wherein one carriage (55, 65) with the carriage drive (57, 67) is movable parallel to the rail system (40) and one carriage (56, 66) with the carriage drive (58, 68) is movable orthogonally to the rail system (40).

11. Remelting plant according to claim 10, wherein the first carriage (55, 65) is arranged below or above the second carriage (56, 66).

12. Remelting plant according to one of the preceding claims, wherein the lower flexible area (175) is a bellows.

13. Remelting plant according to one of the preceding claims, wherein the main column (10) is anchored in a foundation.

14. Remelting plant according to one of the preceding claims, wherein the main column (10) is directly connected to the frame (30) and the rail system (40).

15. Remelting plant according to one of the preceding claims, comprising at least two melting stations (50, 60) or two melting stations (50, 60).

16. Remelting plant according to one of the preceding claims, wherein the power supply (190) is connected to the electrode rod (140) and the upper furnace boiler end (135) via high current lines (200, 210).

17. Method for operating a remelting plant comprising the following steps: Inserting an electrode at a loading position into a crucible (70, 80) of a melting station (50, 60) with two carriages (55, 56, 65, 66) arranged one above the other, which carry the crucible (70, 80) in a central opening and are each connected to a carriage drive (57, 58, 67, 68) by means of which they can be moved horizontally on the melting stations (50, 60), wherein one carriage (55, 65) with the carriage drive (57, 67) can be moved parallel to a rail system (40) and one carriage (56, 66) with the carriage drive (58, 68) can be moved orthogonally to the rail system (40); November 7, 2025 23 / 26 Positioning the melting station (50, 60) at an operating position below a furnace boiler (130) through which an electrode rod (140) runs, by horizontal movement along the rail system (40); Centering the electrode under the electrode rod (140) by moving the carriages (55, 56, 65, 66) with the crucible (70, 80) by means of the carriage drives (57, 58, 67, 68) and clamping the centered electrode to the electrode rod (140); The furnace boiler (130) is placed on the crucible (70, 80) by lowering a lower support (100) on a guide column (20), wherein the lower support (100) is lowered further after the furnace boiler (130) is placed on the crucible (70, 80) to create a detachable connection between the furnace boiler (130) and the lower support (100). The holder (100) is released, whereby a flexible area (175) of a vacuum feedthrough (170) is compressed, so that the guide column (20) including the parts suspended from it and the clamped electrode, together with their weight, rests on load cells (230, 240); - Carrying out the remelting process by supplying current to the electrode and the crucible (70, 80) while lowering an upper holder (90) on the guide column (20), whereby the measured values ​​of the load cells (230, 240) are used to control the lowering process. November 7, 2025 24 / 26

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