EP0053200B1 - Arc furnaces electrode - Google Patents

Arc furnaces electrode Download PDF

Info

Publication number
EP0053200B1
EP0053200B1 EP80107523A EP80107523A EP0053200B1 EP 0053200 B1 EP0053200 B1 EP 0053200B1 EP 80107523 A EP80107523 A EP 80107523A EP 80107523 A EP80107523 A EP 80107523A EP 0053200 B1 EP0053200 B1 EP 0053200B1
Authority
EP
European Patent Office
Prior art keywords
electrode according
clamping
shaft
active part
collet
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP80107523A
Other languages
German (de)
French (fr)
Other versions
EP0053200A1 (en
Inventor
Dieter Dr. Zöllner
Claudio Dipl.-Ing. Conradty
Friedrich Rittmann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Arc Technologies Systems Ltd
Original Assignee
Arc Technologies Systems Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Arc Technologies Systems Ltd filed Critical Arc Technologies Systems Ltd
Priority to EP80107523A priority Critical patent/EP0053200B1/en
Priority to AT80107523T priority patent/ATE22383T1/en
Priority to DE8080107523T priority patent/DE3071765D1/en
Priority to ZA817978A priority patent/ZA817978B/en
Priority to CA000390225A priority patent/CA1173482A/en
Priority to FI813636A priority patent/FI813636L/en
Priority to NZ199015A priority patent/NZ199015A/en
Priority to AU77694/81A priority patent/AU546162B2/en
Priority to IN1319/CAL/81A priority patent/IN155086B/en
Priority to HU813541A priority patent/HU192078B/en
Priority to KR8104570A priority patent/KR870000098B1/en
Priority to YU02797/81A priority patent/YU279781A/en
Priority to GR66642A priority patent/GR77313B/el
Priority to US06/326,068 priority patent/US4481500A/en
Priority to PT74061A priority patent/PT74061B/en
Priority to DK532781A priority patent/DK532781A/en
Priority to ES508108A priority patent/ES8301088A1/en
Priority to DD81235287A priority patent/DD208283A5/en
Priority to NO814093A priority patent/NO814093L/en
Priority to TR21916A priority patent/TR21916A/en
Priority to JP56194313A priority patent/JPS57119493A/en
Priority to PL23405981A priority patent/PL234059A1/xx
Priority to SU813360407A priority patent/SU1093266A3/en
Priority to GB8136351A priority patent/GB2092418A/en
Publication of EP0053200A1 publication Critical patent/EP0053200A1/en
Application granted granted Critical
Publication of EP0053200B1 publication Critical patent/EP0053200B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00—Heating by electric discharge
    • H05B7/02—Details
    • H05B7/06—Electrodes
    • H05B7/08—Electrodes non-consumable
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00—Heating by electric discharge
    • H05B7/02—Details
    • H05B7/06—Electrodes
    • H05B7/08—Electrodes non-consumable
    • H05B7/085—Electrodes non-consumable mainly consisting of carbon
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00—Heating by electric discharge
    • H05B7/02—Details
    • H05B7/10—Mountings, supports, terminals or arrangements for feeding or guiding electrodes
    • H05B7/101—Mountings, supports or terminals at head of electrode, i.e. at the end remote from the arc

Definitions

  • the invention relates to an electrode for arc melting furnaces, in particular for the production of electrical steel, consisting of a metallic, liquid-cooled upper shaft and a replaceable lower active part made of consumable material, in particular graphite, the connection between the upper shaft and the active part being made by means of a clamping device having clamping jaws , which holds the metal shaft and the active part together.
  • Electrodes for arc melting furnaces are exposed to strong thermal and mechanical stresses.
  • the strong thermal stresses result from the high working temperatures in such arc melting furnaces, especially in the production of electrical steel.
  • scrap dislocations When the electrodes are retracted, large mechanical loads result from contact with scrap and scrap parts that slip into the melt (so-called scrap dislocations).
  • the electrodes are vibrated in an electromagnetic manner, which can assume considerable frequencies and amplitudes.
  • large acceleration forces occur which act on the electrodes as bending or torsional stresses.
  • the overall rough and dusty operation in steel production Because of these conditions, the connection of the shaft to the active part in such electrodes poses considerable difficulties. Nevertheless, it is important to design the connection between the shaft and the active part to be simple, easily detachable and result in low electrical losses.
  • the shaft has a sleeve or the like at its lower end, which has an internal thread.
  • a blind hole with an internal thread is also formed at the upper end of the active part.
  • a screw nipple is screwed into these two internal threads, which preferably consists of the same material as the active part, i.e. primarily made of graphite.
  • An electrode of the type required in the preamble of patent claim 1 has already become known (DE-OS 2811 877), which in principle allows a used active part to be easily detached from the upper shaft and a used active part to be reconnected to the shaft.
  • This known construction is characterized in that the current transfer between the metal shaft and the active part and the detachable connection between the shaft and the active part have been functionally separated.
  • the fastening device of the known electrode requires a special design of the upper end of the active part.
  • the upper end of the active part is namely provided with a specially designed connector, which consists of a round plate, on the underside of which there is an axial collar corresponding to the plate diameter and on the upper side of which there is an extension of smaller diameter which has a radially projecting edge.
  • a tension screw for bracing the connector with the active part is arranged in a central bore of the connector.
  • the upper section of the active part is designed in such a way that it encloses the head of the lag screw and engages in the collar, which is conical at the point of contact. This prevents the upper end of the active part from breaking apart under the action of transverse forces and the tension screw.
  • the fastening device On the side of the shaft, the fastening device comprises a cage in the form of a hollow cylinder, which is provided with several recesses on its circumference at the lower end, into which clamping bodies are inserted. These are radially movable and have the shape of balls or rollers.
  • the cage is connected to a hydraulic cylinder with a piston, through which the cage and with it the clamping bodies can be moved in the axial direction relative to the cylinder.
  • the clamping bodies cooperate with an oblique control edge, so that the clamping bodies are moved radially inward by the control edge when lifting by the hydraulic cylinder, as a result of which they are below an edge of an extension of the connection piece to the plant. This results in a positive locking of the active part with the shaft.
  • the fastening device of the known electrode described is extremely complicated. This results primarily from the necessity that the active part must be provided with a specially designed connection piece which has to be clamped to the upper end of the active part by means of a lag screw. This construction is necessary because the material of the active part is subjected to tension in the selected arrangement. The tensile strength of relevant materials for active parts, especially graphite, is considerably lower than the compressive strength of the materials in question. The arrangement chosen in the known solution with connection piece and tension screw for the active part clearly increases the cost of these electrodes considerably.
  • Another disadvantage of the system is the requirement to have metallic load-bearing parts uncooled as fastening elements in the hot active part of the electrode.
  • an electrode clamping device for conventional electrodes consisting of a series of axially screwable graphite cylinders.
  • the support head of this clamping device has a downwardly tapering bore, the smallest diameter of which is located on the lower end face of the support head is just sufficient to accommodate an electrode stump.
  • Balls are arranged in the annular space which widens upwards around the electrode stump and wedges against the side surfaces of the conical bore and against the electrode stump under the weight of the electrode pulling downwards. This will pinch the electrode. It is disadvantageous with this type of electrode clamping that the entire electrical current flows over the balls, whereby extremely punctiform contact points are formed, which entail very high contact resistances.
  • clamping means are provided, by means of which the clamping jaws can be moved in the axial direction, which pulls the active part in the direction of the metal shaft, and in that the clamping jaws have inclined surfaces, by means of which, during movement or pressurization of the clamping jaws in the axial direction, radial movement or force components of the clamping jaws which clamp the active part can be generated.
  • the invention is based on the fact that the mechanical and electrical contact of the two electrode sections should be as optimal as possible for the reliable operation of a water-cooled combination arc electrode.
  • the clamping devices acting laterally and under pressure on the active electrode part are designed in such a way that when they are tightened in the radial direction, a tensile force is simultaneously generated in the axial direction , in such a way that this tensile force presses the active part of the electrode against the upper shaft, as a result of which an optimal broad-area electrical contact between the two contact surfaces of the electrode parts is achieved.
  • this is done by using a multi-part clamping device which, when clamped, has inclined surfaces sliding against one another, part of the clamping device, which comprises an inclined surface with the component facing upwards, being pulled upwards by appropriate clamping means.
  • a radial force which is directed inwards or outwards, depending on the orientation, and an axially upward force is transmitted to an opposite, inclined surface having a downward-pointing component of another part of the clamping device.
  • the axial tensile force that is exerted on the part of the clamping device with the component of the inclined surface facing upward can be maintained during the operation of the electrode in order to ensure permanent contact between the two electrode parts, as is the case, for example, in FIG happens.
  • the inventive clamping device he especially in contrast to the previously known constructions that work with screw nipples, allows a simple and quick release of a used active part from the shaft. The same applies to attaching an unused active part to the shaft. As a result, the electrodes according to the invention can be operated efficiently, saving considerable set-up times.
  • connection section of the active parts Since it is not necessary to provide the connection section of the active parts with special constructions in the electrodes according to the invention, it is also possible to consume the connection section of the active parts according to the invention without further notice. As a result, considerable material savings or high material utilization compared to the known solutions are achieved.
  • the construction according to the invention also allows cheaper material to be used for the active parts in high-performance electrodes than is currently used for such high-performance electrodes.
  • graphite with the following physical properties is used for high-performance electrodes:
  • the solution according to the invention therefore makes it possible in a considerably simplified manner to functionally separate the power supply between the current-carrying components of the shaft and the active part and the clamping device for mechanically connecting the two components of the electrode. This results in particularly simple and material-appropriate training options for both the electrical connection and the mechanical connection between the shaft and the active part.
  • the clamping device can have a separate cooling system or can be connected to the cooling device of the shaft.
  • the clamping device can also detect the active part in its upper area from the inside and / or outside. The only requirement is that the clamping force essentially places pressure on the material of the active part.
  • the clamping device acts directly on the active part according to the invention, it is only necessary to adjust the active part depending on the type of clamping device by forming fitting points, openings, recesses and grooves.
  • the respective shape of the connection area of the active part can already be produced as such during the manufacture of the active part.
  • the active part can be used in unchanged form or even without post-processing connected to the basic manufacturing process.
  • the clamping device can advantageously be designed as a clamping sleeve.
  • the clamping force is applied to the active part via the outer surface of the clamping sleeve. According to the other possibility, this takes place via the inner surface of the clamping sleeve.
  • the clamping sleeve can either be formed in one piece and provided with a longitudinal slot, or it can be composed of a number of segments.
  • a further specific embodiment of the electrode according to the invention is that the clamping device detects the active part on its outer surface, the current-carrying component of the metal part is arranged within the clamping sleeve of the clamping device and the clamping sleeve is surrounded by a tube, on the inside of which wedge surfaces are arranged which cooperate with wedge surfaces on the clamping sleeve.
  • This embodiment primarily has the advantage that the tube surrounding the clamping sleeve not only serves to control the clamping sleeve, but also effectively protects the overall arrangement against thermal and mechanical attack, after this outer tube can be easily formed by the tube sufficient wall thickness is given and the outside is given a corresponding coating. It is also possible to supply the cooling medium to the individual components of the shaft via this tube in order to cool the tube and these components. This results in a particularly compact structure of this embodiment of the electrode according to the invention.
  • the construction mentioned also has considerable advantages with regard to the design of the active part.
  • the active part does not require any special training for connection to the clamping device. Only to increase safety, it may be necessary to provide the circumferential surface of the active part with a circumferential groove in which the clamping device engages in order to thereby increase the transferable force.
  • the active part can have a flat end face on the connection side. This makes it possible to provide the connection side of the active part with an internally threaded blind hole for screw nipples. In this way, the upper section of the active part designed in this way can easily be supplied for consumption by connecting this upper section to the lower end of an active part to be used using a screw nipple.
  • a further embodiment of the electrode according to the invention is characterized in that the clamping device is arranged within the current-carrying component of the shaft and the clamping sleeve engages the active part on a clamping pin formed thereon.
  • This embodiment is characterized in that the diameter of the shaft can be kept relatively small, so that the outside diameter of the shaft can essentially correspond to the outside diameter of the active part, which is of considerable practical importance.
  • the pressure arrangement comprises a pressure sleeve which lies with its conical inner surface against the correspondingly shaped conical outer surface of the clamping sleeve.
  • a second embodiment consists in the fact that the pressure arrangement comprises a mushroom-shaped tappet, which rests with its conical outer surface on a correspondingly conically shaped inner surface of the clamping sleeve.
  • the directly adjacent connection parts of the clamping device on the one hand and the active part on the other hand can be designed both cylindrical and conical. With a conical design, in addition to the non-positive connection, there is also a partially positive fixing of the components to one another.
  • the effective outer or inner surface of the clamping sleeve has additional projections that engage in corresponding recesses on the active part. It is particularly advantageous if the projections to form a snap-in coupling are mounted in a radially flexible manner when the active part is slid onto the clamping sleeve, which can be achieved by assigning springs to the movable projections.
  • the clamping device can also be controlled hydraulically or pneumatically.
  • the pressure arrangement of the clamping sleeve has hydraulically or pneumatically axially movable wedges for this purpose. These wedges combine positive and positive locking.
  • the pressure arrangement of the clamping sleeve has hydraulically or pneumatically radially movable plungers which act accordingly on the clamping sleeve to generate the clamping force.
  • the current-carrying component can be designed as a solid rod which merges into a contact plate at its lower end.
  • the current-carrying component can be produced in a particularly material-saving manner.
  • the outside of the solid rod can be surrounded by cheaper material, possibly provided with a cooling system, in order to protect the current-carrying solid rod from loads of both thermal and mechanical nature.
  • the contact plate provides a large contact area between the current-carrying component of the shaft and the active part, with the result of effective current transmission at this contact area. For this purpose, it is recommended that the outside diameter of the contact plate corresponds approximately to the outside diameter of the active part.
  • the current-carrying component of the shaft is designed as a tube and the clamping device is arranged within this tube, it is advantageous that the outside diameter of the tube corresponds approximately to the outside diameter of the active part.
  • relevant electrodes consisting of a metallic, liquid-cooled upper shaft and a replaceable lower active part made of consumable material
  • the attached figures and accordingly also their description are limited to the components essential to the invention. Only in FIG. 4 is the shaft of a relevant electrode shown in more detail for the sake of completeness.
  • the clamping device designated overall by 40, surrounds the shaft designated overall by 1.
  • the clamping device 40 comprises a clamping sleeve 41.
  • This clamping sleeve 41 concentrically surrounds the power supply tube 11 of the shaft 1. It has clamping jaws 42 with clamping surfaces 42a formed thereon at its lower end.
  • the clamping jaws 42 of the clamping sleeve 41 can represent separate elements or can be produced by corresponding longitudinal slots in the clamping sleeve 41. All that matters is that the jaws 42 are radially movable.
  • the clamping sleeve 41 is concentrically surrounded by a tube 43, on the inside of which in the region of the clamping jaws 42 are arranged wedge surfaces 43a which interact with wedge surfaces 42b of the clamping jaws 42 in a manner to be described in more detail.
  • a circumferential groove 24 is formed in the lateral surface, into which, as shown, the clamping jaws 42 can engage with their clamping surfaces 42a. In order to make this possible, the clamping sleeve 41 and the outer tube 43 can be moved axially relative to one another.
  • the clamping surfaces 42b and 43a disengage, as a result of which the clamping jaws 42 can move radially outwards. In this position of the jaws 42, the upper end of the active part 2 can be inserted between them.
  • the clamping sleeve 41 and the tube 43 are pushed together, the clamping surfaces 42b and 42a come into engagement, as a result of which the clamping jaws 42 are moved radially inward until their clamping surfaces 42b come into contact with the upper wall surface of the circumferential groove 24 of the active part 2.
  • the clamping sleeve 41 and the tube 43 are then moved upwards together, as a result of which the end face contact surface 23 of the active part 2 comes into electrically conductive contact with the contact surface 14 of the power supply tube 11.
  • the embodiment according to FIG. 2 differs from that according to FIG. 1 primarily in that the current-carrying component of the shaft 1 is designed differently than in the previous constructions. It is designed as a solid rod 15 which merges into a contact plate 16 at its lower end.
  • the outer diameter of the contact plate 16 corresponds approximately to the outer diameter of the active part 2. This not only achieves a very material-saving design of the current-carrying component of the shaft 1, but also a large contact area between the contact plate 16 and the relevant end face 23 of the active part 2 is achieved.
  • this can be surrounded by a possibly cooled protective tube 17 made of a cheaper material than that of the current-carrying component 15, 16.
  • the active part 2 can consist of several sections, two of which are connected to each other by means of a screw nipple 25.
  • the uppermost section of the active part 2 which is to be regarded as an adapter and has the circumferential groove 24, has on its upper end face a blind bore 26 which is provided with an internal thread and is suitable for receiving a screw nipple 25.
  • this section of the active part if it is no longer suitable as an adapter, can be connected to the active part 2 as a section to be consumed and then consumed, as a result of which no material is lost.
  • the clamping device lying inside the power supply pipe 11, designated overall by 50, consists of a clamping sleeve 51 and a pressure sleeve 52 concentrically surrounding it.
  • This pressure sleeve 52 has a conical inner surface 53 which bears on the correspondingly shaped conical outer surface of the clamping sleeve 51 .
  • the active part has at its upper end a conical enlargement to the free end of the clamping pin 27, which is inserted between the clamping sleeve when the jaws have moved apart, whereupon the jaws of the clamping sleeve by a corresponding relative movement between the clamping sleeve 51 and the pressure sleeve 52 Clamping sleeve 51 are brought into the clamping system on the clamping pin 27. Subsequently, the clamping sleeve 51 and the pressure sleeve 52 are moved axially upward together in order to bring the contact surface 23 of the active part 2 into an electrically conductive connection with the contact surface 14 of the power supply tube 11.
  • FIG. 4 relates to an arrangement in which the clamping device designated overall by 60 essentially corresponds to the clamping device according to FIG. However, the design of the shaft 1 and the control of the clamping device 60 are explained in more detail in FIG. 4.
  • the clamping device 60 comprises a clamping sleeve 61 which is connected to an actuating element 62.
  • the clamping sleeve 61 and the actuating element 62 are concentrically surrounded by a pressure tube 63, on the inner surface of which a conical clamping surface 64 is formed in the region of the clamping sleeve 61.
  • the jaws of the clamping sleeve 61 are moved radially by a corresponding relative movement between the clamping sleeve 61 and the conical clamping surface 64.
  • the pressure sleeve 63 with the conical clamping surface 64 is arranged in a stationary manner in that the pressure sleeve 63 is fitted into the power supply pipe 11 with the interposition of electrical insulation.
  • the clamping sleeve 61 is moved axially via the actuating element 62.
  • a mechanical-hydraulic actuating device is arranged, which is denoted overall by 100.
  • This consists of a cylinder 101 in which a piston 102 is slidably mounted. This piston 102 is connected to the pull rod 62.
  • a spring 103 is clamped between the piston 102 and a stationary stop of the cylinder 101 in such a way that it always tries to pull the actuating element 62 and with it the active part 2 upwards via the clamping sleeve 61.
  • This coating 18 consists of a suitable material that withstands the prevailing thermal and mechanical stresses.
  • the electrode is held in a feedthrough in the lid of the furnace by a holding device which acts on the shaft 1 and is designated overall by 200.
  • This holding device 200 can be designed in any manner and therefore not to be described in more detail.
  • FIG. 5 shows the clamping device 60 according to FIG. 4 in detail. 5 that the pressure sleeve 63 itself can be made of an electrically insulating material, so that the pressure sleeve 63 can rest directly on the power supply pipe.
  • the conical clamping surface 64 is designed as a separate component and is connected in a suitable manner to the pressure sleeve 63.
  • the clamping device which is designated as a whole by 70, also lies within the power supply tube 11 of the shaft 1, but, in contrast to the construction described above, engages in a correspondingly shaped blind hole 21 with an undercut clamping surface 22 in the active part 2.
  • the clamping device 70 has an actuating element 71 which is shaped like a mushroom at its end and is axially movable.
  • the clamping sleeve 72 is located at the lower end of a stationary tube 73, which is electrically isolated from the power supply tube 11 of the shaft 1 by the interposition of insulation or due to the formation of an insulating material.
  • the clamping jaws of the clamping sleeve 72 are moved radially outwards, while when the actuating element 71 is moved downwards, the clamping jaws of the clamping sleeve 72 are movable radially inwards. In the radially inwardly moved position of the clamping jaws of the clamping sleeve 72, the clamping device 70 can be inserted into the blind hole 21 of the active part 2.
  • the actuating element 71 is then moved upward, so that the clamping jaws of the clamping sleeve 72 move outwards, as a result of which the clamping surfaces 74 of the clamping sleeve 72 engage behind the undercut clamping surface 22 of the blind hole 21 of the active part 2. Thereafter, the actuating element 71 is moved upwards until the contact surface 23 of the active part 2 comes into contact with the contact surface 14 of the power supply tube 11 of the shaft 1, in order in this way to establish the electrical connection between the current-carrying component of the shaft 1 and the active part 2 .
  • the main focus is on the fact that the clamping force exerted by the respective clamping device directly on the active part essentially stresses the material of the active part.
  • the active part is subjected to tension due to its own weight in the usual way.
  • the current-carrying components of the arrangement consist of a suitable electrically conductive material, such as. B. copper or a corresponding metal alloy. Both the current-carrying and the other components of the shaft are cooled accordingly and protected against thermal and mechanical overloading by means of coatings.
  • the parallel guides used between the individual components can be coated or coated with graphite or similar high-temperature-resistant lubricating materials in order to ensure good sliding conditions even at high temperatures and high mechanical loads.
  • the coatings in question expediently consist of high-temperature-resistant, ceramic materials.
  • the active parts consist primarily of graphite.

Landscapes

  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Physics & Mathematics (AREA)
  • Discharge Heating (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Furnace Details (AREA)
  • Clamps And Clips (AREA)
  • Luminescent Compositions (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Processing Of Solid Wastes (AREA)
  • Liquid Crystal Substances (AREA)
  • Electric Stoves And Ranges (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
  • Steroid Compounds (AREA)

Abstract

The invention concerns an electrode for arc furnaces, especially for electrosteel production, comprising a metallic liquid-cooled upper shaft (1) and an exchangeable lower active portion (2) of self-consuming material, particularly graphite, whereby a securing means is provided which is electrically insulated against the current-conducting components (11) of the shaft (1) and said securing means detachably connects the shaft (1) with the active portion (2) as well as holding the contact surfaces of the active portion (23) pressed against the contact surfaces (14) of the current-conducting components (11) of said shaft. To further develop an electrode of this type, which also provides the possibility of rapid and simple disconnection or connection with respect to the shaft (1) and the active portion (2) with a simple design, especially of the area of the active portion on the connection side, the securing device is designed as a clamping means (40; 60) which takes direct effect on the upper end of the active portion (2) in such manner that the clamping force essentially pressure-loads the material of the active portion (2), whereby the physical properties of the material of the active portion (2) are so exploited that no complicated designs are required on the connection side for said active portion (2).

Description

Die Erfindung betrifft eine Elektrode für Lichtbogenschmelzöfen, insbesondere zur Elektrostahlherstellung, bestehend aus einem metallischen, flüssigkeitsgekühlten oberen Schaft und einem ersetzbaren unteren Aktivteil aus sich verbrauchendem Material, insbesondere Graphit, wobei die Verbindung zwischen dem oberen Schaft und dem Aktivteil mittels einer, Klemmbacken aufweisenden Klemmvorrichtung erfolgt, welche den Metallschaft und den Aktivteil zusammenhält.The invention relates to an electrode for arc melting furnaces, in particular for the production of electrical steel, consisting of a metallic, liquid-cooled upper shaft and a replaceable lower active part made of consumable material, in particular graphite, the connection between the upper shaft and the active part being made by means of a clamping device having clamping jaws , which holds the metal shaft and the active part together.

Elektroden für Lichtbogenschmelzöfen sind starken thermischen und mechanischen Beanspruchungen ausgesetzt. Die starken thermischen Beanspruchungen resultieren aus den hohen Arbeitstemperaturen bei derartigen Lichtbogenschmelzöfen, insbesondere bei der Elektrostahlherstellung. Grosse mechanische Belastungen ergeben sich beim Einfahren der Elektroden durch Berührung mit Schrott und in die Schmelze einrutschende Schrottteile (sog. Schrottversetzungen). Darüber hinaus werden die Elektroden auf elektromagnetische Weise in Schwingungen versetzt, die erhebliche Frequenzen und Amplituden annehmen können. Hierdurch treten grosse Beschleunigungskräfte auf, die auf die Elektroden als Biege- oder Torsionsbeanspruchungen wirken. Hinzu kommt der insgesamt rauhe und staubbehaftete Betrieb bei der Stahlherstellung. Aufgrund dieser Bedingungen wirft die Verbindung des Schafts mit dem Aktivteil bei derartigen Elektroden erhebliche Schwierigkeiten auf. Trotzdem kommt es darauf an, die Verbindung zwischen dem Schaft und dem Aktivteil im Aufbau einfach, leicht lösbar und geringe elektrische Verluste ergebend zu gestalten.Electrodes for arc melting furnaces are exposed to strong thermal and mechanical stresses. The strong thermal stresses result from the high working temperatures in such arc melting furnaces, especially in the production of electrical steel. When the electrodes are retracted, large mechanical loads result from contact with scrap and scrap parts that slip into the melt (so-called scrap dislocations). In addition, the electrodes are vibrated in an electromagnetic manner, which can assume considerable frequencies and amplitudes. As a result, large acceleration forces occur which act on the electrodes as bending or torsional stresses. Added to this is the overall rough and dusty operation in steel production. Because of these conditions, the connection of the shaft to the active part in such electrodes poses considerable difficulties. Nevertheless, it is important to design the connection between the shaft and the active part to be simple, easily detachable and result in low electrical losses.

Bislang hatten sich in erster Linie Schraubverbindungen zwischen dem Schaft und dem Aktivteil durchgesetzt (vgl. als Beispiel aus einem umfangreichen Stand der Technik die DE-AS 2 739 483). Bei dieser Verbindungsart weist der Schaft an seinem unteren Ende eine Muffe oder dergleichen auf, die ein Innengewinde besitzt. Am oberen Ende des Aktivteils ist ein Sackloch mit ebenfalls einem Innengewinde ausgebildet. In diese beiden Innengewinde wird ein Schraubnippel eingeschraubt, der vorzugsweise aus demselben Material wie der Aktivteil besteht, d.h. in erster Linie aus Grafit.So far, primarily screw connections between the shaft and the active part have prevailed (cf. DE-AS 2 739 483 as an example from an extensive prior art). In this type of connection, the shaft has a sleeve or the like at its lower end, which has an internal thread. A blind hole with an internal thread is also formed at the upper end of the active part. A screw nipple is screwed into these two internal threads, which preferably consists of the same material as the active part, i.e. primarily made of graphite.

Für derartige Schraubverbindungen sind spezielle Gewinde entwickelt worden. Diese Gewinde sind nicht nur an das Material des Aktivteils bzw. der Schraubnippel angepasst, sondern sollen auch weitgehend den geschilderten Betriebsbedingungen Rechnung tragen. Das Gewinde muss hierfür möglichst weitgehend selbsthemmend sein. Es muss darüber hinaus gute elektrische Kontaktflächen bilden, da zumindest streckenweise ein nicht unerheblicher Teil der Strommenge über den Schraubnippel läuft. Darüber hinaus wurden Tabellen entwickelt, die angeben, mit welchem Drehmoment im Einzelfall die Schraubnippel angezogen werden müssen, um die Kontaktflächen zwischen dem Schaft und dem Aktivteil in die gewünschte Druckanlage zu bringen, die für einen ausreichenden elektrischen Kontakt zwischen diesen Kontaktflächen sorgt.Special threads have been developed for such screw connections. These threads are not only adapted to the material of the active part or the screw nipple, but should also largely take into account the operating conditions described. The thread must be as self-locking as possible. In addition, it must form good electrical contact surfaces, since at least in places a not inconsiderable part of the amount of electricity runs over the screw nipple. In addition, tables have been developed which specify the torque with which the screw nipples must be tightened in individual cases in order to bring the contact surfaces between the shaft and the active part into the desired pressure system, which ensures sufficient electrical contact between these contact surfaces.

Die Schraublösung hat sich zwar im Einsatz als solche bewährt. Jedoch gestaltet sich bei manchen Anwendungen das Wechseln der Aktivteile langwierig und aufwendig. In diesem Zusammenhang wären Konstruktionen wünschenswert, die bei ausreichender thermischer und mechanischer Festigkeit ein schnelleres Lösen eines verbrauchten Aktivteils von dem zugehörigen Schaft bzw. ein zügigeres und einfacheres Anbringen eines unverbrauchten Aktivteils an dem Schaft ermöglichen. Darüber hinaus zwingt die zunehmende Verteuerung der Aktivteile durch Erhöhung der Rohstoff- und Energiekosten zu einer vollständigen Nutzung des Materials der Aktivteile.The screw solution has proven itself as such in use. However, in some applications, changing the active parts is tedious and time-consuming. In this context, constructions would be desirable which, with sufficient thermal and mechanical strength, enable a used active part to be detached from the associated shaft more quickly or an unused active part to be attached to the shaft more quickly and easily. In addition, the increasing cost of the active parts due to increased raw material and energy costs is forcing full use of the material of the active parts.

Es ist bereits eine Elektrode der im Oberbegriff des Patentanspruchs 1 vorausgesetzten Art bekannt geworden (DE-OS 2811 877), die es grundsätzlich gestattet, ein verbrauchtes Aktivteil vom oberen Schaft einfach zu lösen und ein verbrauchtes Aktivteil wieder an den Schaft anzuschliessen. Diese bekannte Konstruktion ist dadurch charakterisiert, dass der Stromübergang zwischen dem Metallschaft und dem Aktivteil und die lösbare Verbindung zwischen Schaft und Aktivteil funktionsmässig getrennt worden sind. Allerdings setzt die Befestigungseinrichtung der bekannten Elektrode eine spezielle Ausbildung des oberen Endes des Aktivteils voraus. Das obere Ende des Aktivteils ist nämlich mit einem speziell ausgebildeten Anschlussstück versehen, das aus einer runden Platte besteht, auf deren Unterseite ein dem Plattendurchmesser entsprechender axialer Kragen und auf deren Oberseite ein Fortsatz geringeren Durchmessers angeordnet ist, der einen radial vorspringenden Rand aufweist. In einer zentralen Bohrung des Anschlussstückes ist eine Zugschraube für die Verspannung des Anschlussstücks mit dem Aktivteil angeordnet. Zu diesem Zweck ist das obere Teilstück des Aktivteils in der Weise ausgebildet, dass es den Kopf der Zugschraube umschliesst und in den Kragen eingreift, der an der Berührungsstelle konisch ausgebildet ist. Hierdurch wird ein Auseinanderbrechen des oberen Endes des Aktivteils unter der Wirkung von Querkräften und der Zugschraube verhindert. Auf seiten des Schaftes umfasst die Befestigungseinrichtung einen Käfig in Form eines Hohlzylinders, der am unteren Ende auf seinem Umfang mit mehreren Ausnehmungen versehen ist, in die Klemmkörper eingesetzt sind. Diese sind radial beweglich und haben die Form von Kugeln oder Rollen. Der Käfig steht mit einem Hydraulikzylinder mit einem Kolben in Verbindung, durch den der Käfig und mit ihm die Klemmkörper gegenüber dem Zylinder in axialer Richtung bewegt werden können. Die Klemmkörper wirken dabei mit einer schrägen Steuerkante zusammen, so dass die Klemmkörper beim Anheben durch den Hydraulikzylinder durch die Steuerkante radial nach innen bewegt werden, wodurch sie unterhalb eines Randes eines Fortsatzes des Anschlussstückes zur Anlage gelangen. Hierdurch wird eine formschlüssige Verriegelung des aktiven Teils mit dem Schaft bewirkt.An electrode of the type required in the preamble of patent claim 1 has already become known (DE-OS 2811 877), which in principle allows a used active part to be easily detached from the upper shaft and a used active part to be reconnected to the shaft. This known construction is characterized in that the current transfer between the metal shaft and the active part and the detachable connection between the shaft and the active part have been functionally separated. However, the fastening device of the known electrode requires a special design of the upper end of the active part. The upper end of the active part is namely provided with a specially designed connector, which consists of a round plate, on the underside of which there is an axial collar corresponding to the plate diameter and on the upper side of which there is an extension of smaller diameter which has a radially projecting edge. A tension screw for bracing the connector with the active part is arranged in a central bore of the connector. For this purpose, the upper section of the active part is designed in such a way that it encloses the head of the lag screw and engages in the collar, which is conical at the point of contact. This prevents the upper end of the active part from breaking apart under the action of transverse forces and the tension screw. On the side of the shaft, the fastening device comprises a cage in the form of a hollow cylinder, which is provided with several recesses on its circumference at the lower end, into which clamping bodies are inserted. These are radially movable and have the shape of balls or rollers. The cage is connected to a hydraulic cylinder with a piston, through which the cage and with it the clamping bodies can be moved in the axial direction relative to the cylinder. The clamping bodies cooperate with an oblique control edge, so that the clamping bodies are moved radially inward by the control edge when lifting by the hydraulic cylinder, as a result of which they are below an edge of an extension of the connection piece to the plant. This results in a positive locking of the active part with the shaft.

Die Befestigungseinrichtung der geschilderten bekannten Elektrode ist äusserst kompliziert. Dies resultiert in erster Linie aus der Notwendigkeit, dass der Aktivteil mit einem besonders ausgebildeten Anschlussstück versehen werden muss, das durch eine Zugschraube mit dem oberen Ende des Aktivteils verspannt werden muss. Diese Konstruktion ist deshalb erforderlich, weil bei der gewählten Anordnung das Material des Aktivteils auf Zug beansprucht wird. Die Zugfestigkeit einschlägiger Materialien für Aktivteile, insbesondere Grafit, ist aber erheblich niedriger als die Druckfestigkeit der betreffenden Materialien. Die bei der bekannten Lösung gewählte Anordnung mit Anschlussstück und Zugschraube für den Aktivteil verteuert diese Elektroden ersichtlich erheblich.The fastening device of the known electrode described is extremely complicated. This results primarily from the necessity that the active part must be provided with a specially designed connection piece which has to be clamped to the upper end of the active part by means of a lag screw. This construction is necessary because the material of the active part is subjected to tension in the selected arrangement. The tensile strength of relevant materials for active parts, especially graphite, is considerably lower than the compressive strength of the materials in question. The arrangement chosen in the known solution with connection piece and tension screw for the active part clearly increases the cost of these electrodes considerably.

Ein weiterer Nachteil des Systems ist das Erfordernis, metallische tragende Teile ungekühlt als Befestigungselemente im heissen Aktivteil der Elektrode angeordnet zu haben.Another disadvantage of the system is the requirement to have metallic load-bearing parts uncooled as fastening elements in the hot active part of the electrode.

Bei einer wesentlichen ähnlich ausgebildeten weiteren bekannten Elektrode wird anstelle des geschilderten Kugel-Mechanismus ein Zangen-Mechanismus verwendet (US-PS 3 311 693, Fig. 2). Auch bei dieser Konstruktion muss das obere Ende des Aktivteils mit einem speziell ausgebildeten Anschlussstück versehen werden, sodass für diese Anordnung die selben Nachteile gelten, wie für die zuerst beschriebene Elektroden-Konstruktion.In the case of a substantially similar, known electrode, a pliers mechanism is used instead of the described ball mechanism (US Pat. No. 3,311,693, FIG. 2). With this construction, too, the upper end of the active part must be provided with a specially designed connecting piece, so that the same disadvantages apply to this arrangement as for the electrode construction described first.

Aus der DE-A- 1 440345 ist eine Elektrodenklemmeinrichtung für konventionelle, aus einer Folge von axial aneinander schraubbaren Graphitzylindern bestehenden Elektroden bekannt. Der Tragkopf dieser Klemmeinrichtung weist eine nach unten konisch sich verjüngende Bohrung auf, deren kleinster, an der unteren Stirnfläche des Tragkopfs befindlicher Durchmesser gerade ausreicht, einen Elektrodenstumpf aufzunehmen. In dem um den Elektrodenstumpf herum sich nach oben hin erweiternden Ringraum sind Kugeln angeordnet, die sich unter dem Eigengewicht der nach unten ziehenden Elektrode gegen die Seitenflächen der konischen Bohrung sowie gegen den Elektrodenstumpf verkeilen. Hierdurch wird die Elektrode eingeklemmt. Es ist nachteilig bei dieser Art der Elektrodenklemmung, dass der gesamte elektrische Strom über die Kugeln fliesst, wobei im extrem punktförmige Auflagestellen gebildet werden, welche sehr hohe Übergangswiderstände mit sich bringen. Ferner besteht die Gefahr, dass unter den mechanischen Beanspruchungen der Elektrode beispielsweise in Form von Vibrationen die Klemmung sich kurzfristig löst und der Elektrode erlaubt, ein kleines Stück nach unten zu rutschen. Eine Summierung derartiger kleiner Schritte könnte zur völligen Lösung der Elektrode aus der Klemmung führen.From DE-A-1 440345 an electrode clamping device for conventional electrodes consisting of a series of axially screwable graphite cylinders is known. The support head of this clamping device has a downwardly tapering bore, the smallest diameter of which is located on the lower end face of the support head is just sufficient to accommodate an electrode stump. Balls are arranged in the annular space which widens upwards around the electrode stump and wedges against the side surfaces of the conical bore and against the electrode stump under the weight of the electrode pulling downwards. This will pinch the electrode. It is disadvantageous with this type of electrode clamping that the entire electrical current flows over the balls, whereby extremely punctiform contact points are formed, which entail very high contact resistances. There is also the danger that the mechanical stress on the electrode, for example in the form of vibrations, will cause the clamp to loosen for a short time and allow the electrode to slide down a small distance. A summation of such small steps could lead to the complete release of the electrode from the clamping.

Demgegenüber ist es Aufgabe der Erfindung, eine Elektrode der vorausgesetzten Art so weiterzubilden, dass sich bei Einräumung der Möglichkeit eines schnellen und einfachen Lösens bzw. Anschliessens in bezug auf den Schaft und den Aktivteil eine sichere, den oberen, wassergekühlten Teil einer Kombinationselektrode und den unteren, aktiven Teil in engem, grossflächigen mechanischen sowie elektrischen Kontakt haltende Verbindungsmöglichkeit ergibt.In contrast, it is an object of the invention to further develop an electrode of the presupposed type in such a way that when the possibility of quick and easy disconnection or connection with respect to the shaft and the active part is granted, a safe, the upper, water-cooled part of a combination electrode and the lower part , active part in tight, large-area mechanical and electrical contact-holding connection results.

Diese Aufgabe wird bei einer Elektrode der erfindungsgemässen Art dadurch gelöst, dass Spannmittel vorgesehen sind, durch welche die Klemmbacken in axialer, den Aktivteil in Richtung auf den Metallschaft hinziehender Richtung bewegbar sind, und dass die Klemmbacken Schrägflächen aufweisen, mittels welcher bei Bewegung bzw. Druckbeaufschlagung der Klemmbacken in axialer Richtung, radiale, den Aktivteil einklemmende Bewegungs- bzw. Kraftkomponenten der Klemmbacken erzeugbar sind.This object is achieved in the case of an electrode of the type according to the invention in that clamping means are provided, by means of which the clamping jaws can be moved in the axial direction, which pulls the active part in the direction of the metal shaft, and in that the clamping jaws have inclined surfaces, by means of which, during movement or pressurization of the clamping jaws in the axial direction, radial movement or force components of the clamping jaws which clamp the active part can be generated.

Die Erfindung geht davon aus, dass zum zuverlässigen Betrieb einer wassergekühlten Kombinations-Lichtbogenelektrode der mechanische und elektrische Kontakt der beiden Elektrodenabschnitte möglichst optimal sein sollte. Um diesen Optimalzustand mit einer schnellgängigen Lösung zum mechanischen Ver- und Entkoppeln der beiden Elektrodenteile zu verbinden, werden erfindungsgemäss die seitlich und unter Druck auf den aktiven Elektrodenteil einwirkenden Klemmeinrichtungen so gestaltet, dass bei ihrem Festziehen in radialer Richtung gleichzeitig eine Zugkraft in axialer Richtung erzeugt wird, und zwar derart, dass diese Zugkraft den aktiven Teil der Elektrode an den oberen Schaft anpresst, wodurch ein optimaler breitflächiger elektrischer Kontakt zwischen den beiden Berührungsflächen der Elektrodenteile zustande kommt. Erfindungsgemäss erfolgt dies durch die Verwendung einer mehrteiligen Klemmeinrichtung, welche beim Festklemmen aneinander abgleitende Schrägflächen aufweist, wobei ein Teil der Klemmeinrichtung, welcher eine Schrägfläche mit nach oben gerichteter Komponente umfasst, durch entsprechende Spannmittel nach oben gezogen wird. Hierdurch wird auf eine gegenüberliegende, eine nach unten gerichtete Komponente aufweisende Schrägfläche eines anderen Teils der Klemmeinrichtung sowohl eine radiale, je nach Orientierung nach innen oder aussen gerichtete, wie auch eine axial nach oben gerichtete Kraft übertragen. In Ausführungsbeispielen (Fig. 1, 2, 4 und 5), bei denen der Teil der Klemmeinrichtung mit einer, eine nach unten gerichtete Komponente aufweisenden Schrägfläche ortsfest angeordnet ist, werden die Radial- und Axialkräfte von dem gezogenen Teil der Klemmeinrichtung unter Abstützung auf den anderen, ortsfesten Teil direkt auf den Aktivteil übertragen.The invention is based on the fact that the mechanical and electrical contact of the two electrode sections should be as optimal as possible for the reliable operation of a water-cooled combination arc electrode. In order to combine this optimal state with a fast-moving solution for mechanically coupling and decoupling the two electrode parts, the clamping devices acting laterally and under pressure on the active electrode part are designed in such a way that when they are tightened in the radial direction, a tensile force is simultaneously generated in the axial direction , in such a way that this tensile force presses the active part of the electrode against the upper shaft, as a result of which an optimal broad-area electrical contact between the two contact surfaces of the electrode parts is achieved. According to the invention, this is done by using a multi-part clamping device which, when clamped, has inclined surfaces sliding against one another, part of the clamping device, which comprises an inclined surface with the component facing upwards, being pulled upwards by appropriate clamping means. In this way, both a radial force, which is directed inwards or outwards, depending on the orientation, and an axially upward force is transmitted to an opposite, inclined surface having a downward-pointing component of another part of the clamping device. In exemplary embodiments (FIGS. 1, 2, 4 and 5), in which the part of the clamping device is arranged in a stationary manner with an inclined surface having a downward-pointing component, the radial and axial forces are supported by the pulled part of the clamping device on the transfer another fixed part directly to the active part.

Die axiale Zugkraft, welche auf den Teil der Klemmeinrichtung mit nach oben gerichteter Komponente der Schrägfläche ausgeübt wird, kann während des Betriebs der Elektrode beibehalten werden, um einen andauernden Kontakt zwischen den beiden Elektrodenteilen zu gewährleisten, wie dies beispielsweise in Fig. mittels der Spiralfeder 103 geschieht.The axial tensile force that is exerted on the part of the clamping device with the component of the inclined surface facing upward can be maintained during the operation of the electrode in order to ensure permanent contact between the two electrode parts, as is the case, for example, in FIG happens.

Die erfindungsgemässe Klemmvorrichtung erlaubt, insbesondere im Gegensatz zu den vorbekannten Konstruktionen, die mit Schraubnippeln arbeiten, ein einfaches und schnelles Lösen eines verbrauchten Aktivteils vom Schaft. Ein gleiches gilt für das Anbringen eines unverbrauchten Aktivteils am Schaft. Dadurch kann mit den erfindungsgemässen Elektroden rationell unter Einsparung erheblicher Rüstzeiten gearbeitet werden.The inventive clamping device he especially in contrast to the previously known constructions that work with screw nipples, allows a simple and quick release of a used active part from the shaft. The same applies to attaching an unused active part to the shaft. As a result, the electrodes according to the invention can be operated efficiently, saving considerable set-up times.

Nachdem es bei den erfindungsgemässen Elektroden nicht erforderlich ist, den Anschlussabschnitt der Aktivteile mit besonderen Konstruktionen zu versehen, ist es möglich, den Anschlussabschnitt der erfindungsgemässen Aktivteile ebenfalls ohne weiteres zu verbrauchen. Dadurch wird eine erhebliche Materialeinsparung bzw. eine hohe Materialausnutzung gegenüber den bekannten Lösungen erreicht.Since it is not necessary to provide the connection section of the active parts with special constructions in the electrodes according to the invention, it is also possible to consume the connection section of the active parts according to the invention without further notice. As a result, considerable material savings or high material utilization compared to the known solutions are achieved.

Die erfindungsgemässe Konstruktion erlaubt es darüber hinaus, auch bei Hochleistungselektroden billigeres Material für die Aktivteile zu verwenden, als es derzeit für derartige Hochleistungselektroden eingesetzt wird. Für Hochleistungselektroden wird z.B. Grafit mit folgenden physikalischen Eigenschaften verwendet:

Figure imgb0001
The construction according to the invention also allows cheaper material to be used for the active parts in high-performance electrodes than is currently used for such high-performance electrodes. For example, graphite with the following physical properties is used for high-performance electrodes:
Figure imgb0001

Es handelt sich hierbei um nachverdichtete Elektroden. Diese Elektroden sind z.B. bei einem Durchmesser von ca. 500 mm mit ca. 50 000 bis 55 000 A belastbar.These are post-compressed electrodes. These electrodes are e.g. with a diameter of approx. 500 mm with a load of approx. 50,000 to 55,000 A.

Unter Verwendung der erfindungsgemässen Lösung ist es möglich, Elektroden bei einem Durchmesser von ca. 400 mm mit ca. 50 000 bis 55 000 A zu belasten bei Einsatz eines Grafits mit folgenden physikalischen Eigenschaften:

Figure imgb0002
Using the solution according to the invention, it is possible to load electrodes with a diameter of approx. 400 mm with approx. 50,000 to 55,000 A when using a graphite with the following physical properties:
Figure imgb0002

Dabei handelt es sich um unverdichtete Grafitelektroden. Nachdem bei erfindungsgemässen Elektroden es im Gegensatz zum Stand der Technik nicht erforderlich ist, das obere Ende des Aktivteils mit einem besonderen Anschlussstück zu versehen, kann der Strom unmittelbar von den stromführenden Bauteilen des Schafts in den Aktivteil eingeleitet werden. Hierfür ist es lediglich erforderlich, Kontaktflächen der stromführenden Bauteile des Schafts in Anlage mit der oberen Stirnfläche des Aktivteils zu bringen. Bei den bekannten Konstruktionen war es hingegen in manchen Fällen erforderlich, an den Anschlussstükken der Aktivteile spezielle Kontaktflächen auszubilden (vgl. z. B. US-PS 3311 693), die diese Anordnungen noch weiter verteuerten. Die erfindungsgemässe Lösung erlaubt es deshalb auf erheblich vereinfachte Weise, die Stromzuführung zwischen den stromführenden Bauteilen des Schafts und dem Aktivteil und die Klemmvorrichtung zum mechanischen Verbinden der beiden Bauteile der Elektrode funktionell zu trennen. Dadurch ergeben sich besonders einfache und materialgerechte Ausbildungsmöglichkeiten sowohl für die elektrische Verbindung als auch die mechanische Verbindung zwischen Schaft und Aktivteil.These are undensified graphite electrodes. Since, in contrast to the prior art, it is not necessary in the electrodes according to the invention to provide the upper end of the active part with a special connecting piece, the current can be introduced directly from the current-carrying components of the shaft into the active part. For this it is only necessary to bring contact surfaces of the current-carrying components of the shaft into contact with the upper end face of the active part. In the known constructions, on the other hand, in some cases it was necessary to form special contact surfaces on the connecting pieces of the active parts (see, for example, US Pat. No. 3,311,693), which made these arrangements even more expensive. The solution according to the invention therefore makes it possible in a considerably simplified manner to functionally separate the power supply between the current-carrying components of the shaft and the active part and the clamping device for mechanically connecting the two components of the electrode. This results in particularly simple and material-appropriate training options for both the electrical connection and the mechanical connection between the shaft and the active part.

Zweckmässige Ausbildungen der erfindungsgemässen Lösung sind aus den übrigen Patentansprüchen zu entnehmen.Appropriate designs of the solution according to the invention can be found in the remaining claims.

Danach ergibt sich aufgrund der Trennung der mechanischen und elektrischen Verbindung zwischen Schaft einerseits und Aktivteil andererseits und des unmittelbaren Angriffs der Klemmvorrichtung an dem Material des Aktivteils aufgrund dessen Druckbeanspruchung durch die Klemmkraft eine besonders grosse Fülle an konstruktiven Möglichkeiten.Thereafter, due to the separation of the mechanical and electrical connection between the shaft on the one hand and the active part on the other hand and the direct attack of the clamping device on the material of the active part due to its pressure load by the clamping force, a particularly large abundance of constructive possibilities.

So ist es möglich, die Klemmvorrichtung nicht nur mechanisch, pneumatisch oder hydraulisch zu betätigen. Es ist vielmehr auch die Möglichkeit eingeräumt, dass die Klemmkraft zumindest im wesentlichen durch das Eigengewicht des Aktivteils erzeugt wird.So it is possible to operate the clamping device not only mechanically, pneumatically or hydraulically. Rather, there is also the possibility that the clamping force is generated at least essentially by the weight of the active part.

Ferner kann die Klemmvorrichtung ein separates Kühlsystem aufweisen oder an die Kühleinrichtung des Schafts angeschlossen sein.Furthermore, the clamping device can have a separate cooling system or can be connected to the cooling device of the shaft.

Die Klemmvorrichtung kann darüber hinaus den Aktivteit in dessen oberem Bereich von innen und/oder aussen erfassen. Dabei muss nur die Massgabe eingehalten werden, dass die Klemmkraft das Material des Aktivteils im wesentlichen auf Druck beansprucht.The clamping device can also detect the active part in its upper area from the inside and / or outside. The only requirement is that the clamping force essentially places pressure on the material of the active part.

Nachdem erfindungsgemäss die Klemmvorrichtung unmittelbar auf den Aktivteil einwirkt, ist es lediglich erforderlich, den Aktivteil je nach Art der Klemmvorrichtung durch Ausbildung von Passstellen, Öffnungen, Ausnehmungen und Riefen abzustimmen. Die jeweilige Form des Anschlussbereichs des Aktivteils kann schon bei der Herstellung des Aktivteils als solchem erzeugt werden. Bei besonders vorteilhafter Lösung kann der Aktivteil in unveränderter Form bzw. sogar ohne an den Grundherstellungsprozess angeschlossene Nachbearbeitung eingesetzt werden.After the clamping device acts directly on the active part according to the invention, it is only necessary to adjust the active part depending on the type of clamping device by forming fitting points, openings, recesses and grooves. The respective shape of the connection area of the active part can already be produced as such during the manufacture of the active part. In a particularly advantageous solution, the active part can be used in unchanged form or even without post-processing connected to the basic manufacturing process.

Die Klemmvorrichtung kann mit Vorteil als Klemmhülse ausgebildet sein. Dabei sind zwei Möglichkeiten gegeben. Nach der einen Möglichkeit wird die Klemmkraft über die Aussenfläche der Klemmhülse auf den Aktivteil aufgebracht. Nach der anderen Möglichkeit erfolgt dies über die Innenfläche der Klemmhülse.The clamping device can advantageously be designed as a clamping sleeve. There are two options. According to one possibility, the clamping force is applied to the active part via the outer surface of the clamping sleeve. According to the other possibility, this takes place via the inner surface of the clamping sleeve.

Für die Ausbildung der Klemmhülse stehen vorteilhafterweise mehrere Varianten zur Verfügung. Die Klemmhülse kann entweder einteilig ausgebildet und mit einem Längsschlitz versehen oder aus einer Anzahl von Segmenten zusammengesetzt sein.Several variants are advantageously available for the formation of the clamping sleeve. The clamping sleeve can either be formed in one piece and provided with a longitudinal slot, or it can be composed of a number of segments.

Eine weitere konkrete Ausbildung der erfindungsgemässen Elektrode besteht darin, dass die Klemmvorrichtung den Aktivteil an dessen Mantelfläche erfasst, das stromführende Bauteil des Metallteils innerhalb der Klemmhülse der Klemmvorrichtung angeordnet ist und die Klemmhülse von einem Rohr umgeben ist, an dessen Innenseite Keilflächen angeordnet sind, die mit Keilflächen an der Klemmhülse zusammenwirken. Diese Ausführungsform weist in erster Linie den Vorteil auf, dass das die Klemmhülse umgebende Rohr nicht nur der Steuerung der Klemmhülse dient, sondern darüber hinaus die Gesamtanordnung wirksam gegen thermischen und mechanischen Angriff schützt, nachdem dieses Aussenrohr ohne weiteres entsprechend ausgebildet werden kann, indem dem Rohr eine ausreichende Wandstärke verliehen wird und die Aussenseite mit einer entsprechenden Beschichtung versehen wird. Dabei besteht ferner die Möglichkeit, über dieses Rohr auch das Kühlmedium den einzelnen Bauteilen des Schafts zuzuleiten, um das Rohr und diese Bauteile zu kühlen. Dadurch ergibt sich ein besonders kompakter Aufbau dieser Ausbildungsform der erfindungsgemässen Elektrode.A further specific embodiment of the electrode according to the invention is that the clamping device detects the active part on its outer surface, the current-carrying component of the metal part is arranged within the clamping sleeve of the clamping device and the clamping sleeve is surrounded by a tube, on the inside of which wedge surfaces are arranged which cooperate with wedge surfaces on the clamping sleeve. This embodiment primarily has the advantage that the tube surrounding the clamping sleeve not only serves to control the clamping sleeve, but also effectively protects the overall arrangement against thermal and mechanical attack, after this outer tube can be easily formed by the tube sufficient wall thickness is given and the outside is given a corresponding coating. It is also possible to supply the cooling medium to the individual components of the shaft via this tube in order to cool the tube and these components. This results in a particularly compact structure of this embodiment of the electrode according to the invention.

Die angesprochene Konstruktion weist schliesslich auch erhebliche Vorteile in bezug auf die Gestaltung des Aktivteils auf. Nachdem die Klemmhülse unmittelbar an der Mantelfläche des Aktivteils angreift, bedarf der Aktivteil keiner speziellen Ausbildung für den Anschluss an die Klemmvorrichtung. Lediglich zur Erhöhung der Sicherheit kann es erforderlich sein, die Mantelfläche des Aktivteils mit einer Umfangsnut zu versehen, in die die Klemmvorrichtung eingreift, um dadurch die übertragbare Kraft zu erhöhen. Von besonderem Vorteil ist es, dass der Aktivteil anschlussseitig eine plane Stirnfläche aufweisen kann. Dadurch ist es möglich, die Anschlussseite des Aktivteils bereits mit einem Innengewinde-Sackloch für Schraubnippel zu versehen. Auf diese Weise kann der obere Abschnitt des derart ausgebildeten Aktivteils ohne weiteres dem Verbrauch zugeführt werden, indem dieser obere Abschnitt an das untere Ende eines einzusetzenden Aktivteils unter Verwendung eines Schraubnippels angeschlossen wird.Finally, the construction mentioned also has considerable advantages with regard to the design of the active part. After the clamping sleeve engages directly on the outer surface of the active part, the active part does not require any special training for connection to the clamping device. Only to increase safety, it may be necessary to provide the circumferential surface of the active part with a circumferential groove in which the clamping device engages in order to thereby increase the transferable force. It is particularly advantageous that the active part can have a flat end face on the connection side. This makes it possible to provide the connection side of the active part with an internally threaded blind hole for screw nipples. In this way, the upper section of the active part designed in this way can easily be supplied for consumption by connecting this upper section to the lower end of an active part to be used using a screw nipple.

Eine weitere Ausführungsform der erfindungsgemässen Elektrode ist dadurch gekennzeichnet, dass die Klemmvorrichtung innerhalb des stromzuführenden Bauteils des Schafts angeordnet ist und die Klemmhülse den Aktivteil an einem daran ausgebildeten Klemmzapfen erfasst. Diese Ausführungsform zeichnet sich dadurch aus, dass der Durchmesser des Schafts relativ klein gehalten werden kann, so dass der Aussendurchmesser des Schafts im wesentlichen dem Aussendurchmesser des Aktivteils entsprechen kann, was von erheblicher praktischer Bedeutung ist.A further embodiment of the electrode according to the invention is characterized in that the clamping device is arranged within the current-carrying component of the shaft and the clamping sleeve engages the active part on a clamping pin formed thereon. This embodiment is characterized in that the diameter of the shaft can be kept relatively small, so that the outside diameter of the shaft can essentially correspond to the outside diameter of the active part, which is of considerable practical importance.

Die beschriebene Ausführungsform lässt eine Fülle von Möglichkeiten für die Betätigung der Klemmvorrichtung zu. Nach einer ersten Variante umfasst die Druckanordnung eine Druckhülse, die mit ihrer konischen Innenfläche an der entsprechend geformten konischen Aussenfläche der Klemmhülse anliegt. Eine zweite Ausführungsform besteht darin, dass die Druckanordnung einen pilzartig geformten Zugstössel umfasst, der mit seiner konischen Aussenfläche an einer entsprechend konisch geformten Innenfläche der Klemmhülse anliegt.The described embodiment allows a wealth of possibilities for the actuation of the clamping device. According to a first variant, the pressure arrangement comprises a pressure sleeve which lies with its conical inner surface against the correspondingly shaped conical outer surface of the clamping sleeve. A second embodiment consists in the fact that the pressure arrangement comprises a mushroom-shaped tappet, which rests with its conical outer surface on a correspondingly conically shaped inner surface of the clamping sleeve.

Die unmittelbar aneinanderliegenden Anschlussteile der Klemmvorrichtung einerseits und des Aktivteils andererseits können sowohl zylindrisch als auch konisch gestaltet werden. Bei einer konischen Gestaltung ergibt sich neben der kraftschlüssigen Verbindung auch eine teilweise formschlüssige Fixierung der Bauteile zueinander.The directly adjacent connection parts of the clamping device on the one hand and the active part on the other hand can be designed both cylindrical and conical. With a conical design, in addition to the non-positive connection, there is also a partially positive fixing of the components to one another.

Falls besonders hohe Kräfte zwischen dem Schaft und dem Aktivteil übertragen werden müssen, empfiehlt es sich, neben der kraftschlüssigen Verbindung Mittel einzusetzen, die zur Erhöhung der Sicherheit einen Formschluss zwischen den zu verbindenden Teilen herstellen. Dies ist dadurch möglich, dass die wirksame Aussen- bzw. Innenfläche der Klemmhülse zusätzliche Vorsprünge aufweist, die in entsprechende Ausnehmungen am Aktivteil eingreifen. Dabei ist es von besonderem Vorteil, wenn die Vorsprünge zur Bildung einer Einrastkupplung beim Aufschieben des Aktivteils auf die Klemmhülse radial nachgiebig gelagert sind,-was durch die Zuordnung von Federn zu den beweglichen Vorsprüngen erzielt werden kann.If particularly high forces have to be transmitted between the shaft and the active part, it is advisable to use means in addition to the non-positive connection that produce a positive connection between the parts to be connected to increase safety. This is possible because the effective outer or inner surface of the clamping sleeve has additional projections that engage in corresponding recesses on the active part. It is particularly advantageous if the projections to form a snap-in coupling are mounted in a radially flexible manner when the active part is slid onto the clamping sleeve, which can be achieved by assigning springs to the movable projections.

Wie bereits eingangs betont, kann die Klemmvorrichtung auch hydraulisch oder pneumatisch gesteuert werden.As already emphasized at the beginning, the clamping device can also be controlled hydraulically or pneumatically.

Nach einer ersten Ausführungsform weist hierfür die Druckanordnung der Klemmhülse hydraulisch bzw. pneumatisch axial bewegliche Keile auf. Diese Keile kombinieren Kraft- und Formschluss. Nach einer anderen Variante weist die Druckanordnung der Klemmhülse hydraulisch bzw. pneumatisch radial bewegliche Stössel auf, die auf die Klemmhülse zur Erzeugung der Klemmkraft entsprechend einwirken.According to a first embodiment, the pressure arrangement of the clamping sleeve has hydraulically or pneumatically axially movable wedges for this purpose. These wedges combine positive and positive locking. According to another variant, the pressure arrangement of the clamping sleeve has hydraulically or pneumatically radially movable plungers which act accordingly on the clamping sleeve to generate the clamping force.

Bei einer Ausbildung der erfindungsgemässen Elektrode, bei der die Klemmvorrichtung das stromführende Bauteil des Schafts umgibt, ist es von besonderem Vorteil, dass das stromführende Bauteil als Vollstab ausgebildet werden kann, der an seinem unteren Ende in eine Kontaktplatte übergeht. Hierdurch kann das stromführende Bauteil besonders materialsparend hergestellt werden. Die Aussenseite des Vollstabs kann dabei von billigerem, eventuell mit einem Kühlsystem versehenen Material umgeben sein, um den stromführenden Vollstab vor Belastungen sowohl thermischer als auch mechanischer Natur zu schützen. Die Kontaktplatte ergibt zwischen dem stromführenden Bauteil des Schafts und dem Aktivteil eine grosse Kontaktfläche mit der Folge einer wirkungsvollen Stromübertragung an dieser Kontaktfläche. Hierzu empfiehlt es sich, dass der Aussendurchmesser der Kontaktplatte in etwa dem Aussendurchmesser des Aktivteils entspricht.In the case of an embodiment of the electrode according to the invention in which the clamping device surrounds the current-carrying component of the shaft, it is particularly advantageous that the current-carrying component can be designed as a solid rod which merges into a contact plate at its lower end. As a result, the current-carrying component can be produced in a particularly material-saving manner. The outside of the solid rod can be surrounded by cheaper material, possibly provided with a cooling system, in order to protect the current-carrying solid rod from loads of both thermal and mechanical nature. The contact plate provides a large contact area between the current-carrying component of the shaft and the active part, with the result of effective current transmission at this contact area. For this purpose, it is recommended that the outside diameter of the contact plate corresponds approximately to the outside diameter of the active part.

Nach der bereits angesprochenen anderen grundsätzlichen Konstruktionsvariante, bei welcher das stromführende Bauteil des Schafts als Rohr ausgebildet und die Klemmvorrichtung innerhalb dieses Rohrs angeordnet ist, ist es von Vorteil, dass der Aussendurchmesser des Rohrs in etwa dem Aussendurchmesser des Aktivteils entspricht.According to the other basic design variant already mentioned, in which the current-carrying component of the shaft is designed as a tube and the clamping device is arranged within this tube, it is advantageous that the outside diameter of the tube corresponds approximately to the outside diameter of the active part.

Die Auslegung des Rohrs kann in jeder Hinsicht auf die mechanischen und elektrischen Erfordernisse der Gesamtanordnung optimiert werden. Weitere Einzelheiten und Vorteile der Erfindung ergeben sich aus der Beschreibung von in den Zeichnungen dargestellten Ausführungsbeispielen. Es zeigt:

  • Fig. 1 zeigt ein Ausführungsbeispiel der erfindungsgemässen Elektrode in schematischer Darstellung der wesentlichen Bauteile,
  • Fig. 2 eine der Konstruktion nach Fig. 1 vergleichbare Anordnung, bei der jedoch das stromführende Bauteil des Schafts anders ausgebildet ist,
  • Fig. 3 ein weiteres Ausführungsbeispiel der erfindungsgemässen Elektrode in schematischer Darstellung eines Axialschnittes durch die wesentlichen Bauteile,
  • Fig. einen Axialschnitt durch eine weitere Konstruktionsvariante der erfindungsgemässen Elektrode, wobei die Ausbildung des Schaftes näher dargestellt ist,
  • Fig. 5 einen vergrösserten Axialschnitt durch die Klemmvorrichtung der Anordnung nach Fig. 4, und
  • Fig. 6 eine weitere Ausführungsform der erfindungsgemässen Elektrode in schematischer Darstellung anhand eines Axialschnitts durch die wesentlichen Bauteile.
The design of the tube can be optimized in every respect to the mechanical and electrical requirements of the overall arrangement. Further details and advantages of the invention result from the description of the exemplary embodiments shown in the drawings. It shows:
  • 1 shows an embodiment of the electrode according to the invention in a schematic representation of the essential components,
  • 2 shows an arrangement comparable to the construction according to FIG. 1, but in which the current-carrying component of the shaft is designed differently,
  • 3 shows a further exemplary embodiment of the electrode according to the invention in a schematic illustration of an axial section through the essential components,
  • 1 shows an axial section through a further design variant of the electrode according to the invention, the design of the shaft being shown in more detail,
  • 5 shows an enlarged axial section through the clamping device of the arrangement according to FIG. 4, and
  • Fig. 6 shows a further embodiment of the electrode according to the invention in a schematic representation based on an axial section through the essential components.

Nachdem der grundsätzliche Aufbau von einschlägigen Elektroden, bestehend aus einem metallischen, flüssigkeitsgekühlten oberen Schaft und einem ersetzbaren unteren Aktivteil aus sich verbrauchendem Material bekannt ist, beschränken sich die beigefügten Figuren und demgemäss auch deren Beschreibung auf die erfindungswesentlichen Bauteile. Nur in Fig. 4 ist der Vollständigkeit halber der Schaft einer einschlägigen Elektrode näher dargestellt.After the basic structure of relevant electrodes, consisting of a metallic, liquid-cooled upper shaft and a replaceable lower active part made of consumable material, is known, the attached figures and accordingly also their description are limited to the components essential to the invention. Only in FIG. 4 is the shaft of a relevant electrode shown in more detail for the sake of completeness.

Die Fig. 1 zeigt ein Ausführungsbeispiel der erfindungsgemässen Elektrode. Dabei umgibt die insgesamt mit 40 bezeichnete Klemmvorrichtung den insgesamt mit 1 bezeichneten Schaft. Die Klemmvorrichtung 40 umfasst eine Klemmhülse 41. Diese Klemmhülse 41 umgibt konzentrisch das Stromzuleitungsrohr 11 des Schafts 1. Sie weist an ihrem unteren Ende Klemmbacken 42 mit daran ausgebildeten Klemmflächen 42a auf. Die Klemmbacken 42 der Klemmhülse 41 können separate Elemente darstellen oder durch entsprechende Längsschlitze in der Klemmhülse 41 erzeugt sein. Es kommt lediglich darauf an, dass die Klemmbacken 42 radial beweglich sind.1 shows an embodiment of the electrode according to the invention. The clamping device, designated overall by 40, surrounds the shaft designated overall by 1. The clamping device 40 comprises a clamping sleeve 41. This clamping sleeve 41 concentrically surrounds the power supply tube 11 of the shaft 1. It has clamping jaws 42 with clamping surfaces 42a formed thereon at its lower end. The clamping jaws 42 of the clamping sleeve 41 can represent separate elements or can be produced by corresponding longitudinal slots in the clamping sleeve 41. All that matters is that the jaws 42 are radially movable.

Die Klemmhülse 41 ist konzentrisch umgeben von einem Rohr 43, an dessen Innenseite im Bereich der Klemmbacken 42 Keilflächen 43a angeordnet sind, die mit Keilflächen 42b der Klemmbacken 42 in noch näher zu schildernder Weise zusammenwirken. Am oberen Ende des Aktivteils 2 ist in der Mantelfläche eine Umfangsnut 24 ausgebildet, in die gemäss der Darstellung die Klemmbacken 42 mit ihren Klemmflächen 42a eingreifen können. Um dies zu ermöglichen, sind die Klemmhülse 41 und das äussere Rohr 43 axial relativ zueinander beweglich. Werden die Klemmhülse 41 und das Rohr 43 auseinanderbewegt, gelangen die Klemmflächen 42b und 43a ausser Eingriff, wodurch sich die Klemmbacken 42 radial nach aussen bewegen können. In dieser Stellung der Klemmbacken 42 kann das obere Ende des Aktivteils 2 zwischen diese eingeschoben werden. Beim Zusammenschieben der Klemmhülse 41 und des Rohrs 43 gelangen die Klemmflächen 42b und 42a in Eingriff, wodurch die Klemmbacken 42 radial nach innen bewegt werden, bis ihre Klemmflächen 42b in Anlage mit der oberen Wandungsfläche der Umfangsnut 24 des Aktivteils 2 gelangen. Danach werden die Klemmhülse 41 und das Rohr 43 gemeinsam nach oben bewegt, wodurch die stirnseitige Kontaktfläche 23 des Aktivteils 2 mit der Kontaktfläche 14 des Stromzuleitungsrohrs 11 in elektrisch leitende Berührung gelangt.The clamping sleeve 41 is concentrically surrounded by a tube 43, on the inside of which in the region of the clamping jaws 42 are arranged wedge surfaces 43a which interact with wedge surfaces 42b of the clamping jaws 42 in a manner to be described in more detail. At the upper end of the active part 2, a circumferential groove 24 is formed in the lateral surface, into which, as shown, the clamping jaws 42 can engage with their clamping surfaces 42a. In order to make this possible, the clamping sleeve 41 and the outer tube 43 can be moved axially relative to one another. If the clamping sleeve 41 and the tube 43 are moved apart, the clamping surfaces 42b and 43a disengage, as a result of which the clamping jaws 42 can move radially outwards. In this position of the jaws 42, the upper end of the active part 2 can be inserted between them. When the clamping sleeve 41 and the tube 43 are pushed together, the clamping surfaces 42b and 42a come into engagement, as a result of which the clamping jaws 42 are moved radially inward until their clamping surfaces 42b come into contact with the upper wall surface of the circumferential groove 24 of the active part 2. The clamping sleeve 41 and the tube 43 are then moved upwards together, as a result of which the end face contact surface 23 of the active part 2 comes into electrically conductive contact with the contact surface 14 of the power supply tube 11.

Die Ausführungsform nach Fig. 2 unterscheidet sich von der nach Fig. 1 in erster Linie dadurch, dass das stromführende Bauteil des Schafts 1 anders ausgebildet ist als bei den vorhergehenden Konstruktionen. Es ist nämlich als Vollstab 15 ausgebildet, der an seinem unteren Ende in eine Kontaktplatte 16 übergeht, Dabei entspricht der Aussendurchmesser der Kontaktplatte 16 in etwa dem Aussendurchmesser des Aktivteils 2. Dadurch ist nicht nur eine sehr materialsparende Ausbildung des stromführenden Bauteils des Schafts 1 erreicht, sondern auch eine grosse Kontaktfläche zwischen der Kontaktplatte 16 und der diesbezüglichen Stirnfläche 23 des Aktivteils 2 erzielt. Zum Schutz des Vollwandstabs 15 gegenüber thermischen und mechanischen Einflüssen kann dieses von einem eventuell gekühlten Schutzrohr 17 aus einem billigeren Material als dem des stromführenden Bauteils 15, 16 umgeben sein.The embodiment according to FIG. 2 differs from that according to FIG. 1 primarily in that the current-carrying component of the shaft 1 is designed differently than in the previous constructions. It is designed as a solid rod 15 which merges into a contact plate 16 at its lower end. The outer diameter of the contact plate 16 corresponds approximately to the outer diameter of the active part 2. This not only achieves a very material-saving design of the current-carrying component of the shaft 1, but also a large contact area between the contact plate 16 and the relevant end face 23 of the active part 2 is achieved. To protect the solid wall rod 15 against thermal and mechanical influences, this can be surrounded by a possibly cooled protective tube 17 made of a cheaper material than that of the current-carrying component 15, 16.

In der Figur 1 ist angedeutet, dass das Aktivteil 2 aus mehreren Abschnitten bestehen kann, von denen jeweils zwei benachbarte mittels eines Schraubnippels 25 miteinander verbunden sind.In FIG. 1 it is indicated that the active part 2 can consist of several sections, two of which are connected to each other by means of a screw nipple 25.

Der oberste Abschnitt des Aktivteils 2, der als Art Adapter anzusehen ist und die Umfangsnut 24 besitzt, weist an seiner oberen Stirnseite ein mit einem Innengewinde versehene Sackbohrung 26 auf, die zur Aufnahme eines Schraubnippels 25 geeignet ist. Auf diese Weise kann dieser Abschnitt des Aktivteils, falls er nicht mehr als Adapter geeignet ist, als zu verbrauchender Abschnitt an den Aktivteil 2 angeschlossen und dann verbraucht werden, wodurch kein Material verloren geht.The uppermost section of the active part 2, which is to be regarded as an adapter and has the circumferential groove 24, has on its upper end face a blind bore 26 which is provided with an internal thread and is suitable for receiving a screw nipple 25. In this way, this section of the active part, if it is no longer suitable as an adapter, can be connected to the active part 2 as a section to be consumed and then consumed, as a result of which no material is lost.

Die Fig. 4 bis 6 zeigen Anordnungen, bei denen die jeweilige Klemmvorrichtung innerhalb des stromleitenden Rohrs 11 des Schafts 1 angeordnet ist.4 to 6 show arrangements in which the respective clamping device is arranged within the current-conducting tube 11 of the shaft 1.

Nach Fig. 3 besteht die innerhalb des Stromzuleitungsrohrs 11 liegende, insgesamt mit 50 bezeichnete Klemmvorrichtung aus einer Klemmhülse 51 und einer konzentrisch diese umgebenden Druckhülse 52. Diese Druckhülse 52 weist eine konische Innenfläche 53 auf, die an der entsprechend geformten konischen Aussenfläche der Klemmhülse 51 anliegt. Durch eine entsprechende Relativbewegung zwischen der Klemmhülse 51 und der Druckhülse 52 können die Backen der Klemmhülse radial nach aussen bzw. nach innen bewegt werden. Zum Zusammenwirken mit dieser Klemmvorrichtung weist der Aktivteil an seinem oberen Ende einen konisch sich zum freien Ende vergrössernden Klemmzapfen 27 auf, der bei auseinandergefahrenen Backen der Klemmhülse zwischen diese eingeschoben wird, worauf durch eine entsprechende Relativbewegung zwischen der Klemmhülse 51 und der Druckhülse 52 die Backen der Klemmhülse 51 in Klemmanlage an den Klemmzapfen 27 gebracht werden. Daran anschliessend werden Klemmhülse 51 und Druckhülse 52 gemeinsam axial nach oben bewegt, um die Kontaktfläche 23 des Aktivteils 2 mit der Kontaktfläche 14 des Stromzuleitungsrohrs 11 in elektrisch leitende Verbindung zu bringen.According to FIG. 3, the clamping device lying inside the power supply pipe 11, designated overall by 50, consists of a clamping sleeve 51 and a pressure sleeve 52 concentrically surrounding it. This pressure sleeve 52 has a conical inner surface 53 which bears on the correspondingly shaped conical outer surface of the clamping sleeve 51 . By means of a corresponding relative movement between the clamping sleeve 51 and the pressure sleeve 52, the jaws of the clamping sleeve can be moved radially outwards or inwards. To cooperate with this clamping device, the active part has at its upper end a conical enlargement to the free end of the clamping pin 27, which is inserted between the clamping sleeve when the jaws have moved apart, whereupon the jaws of the clamping sleeve by a corresponding relative movement between the clamping sleeve 51 and the pressure sleeve 52 Clamping sleeve 51 are brought into the clamping system on the clamping pin 27. Subsequently, the clamping sleeve 51 and the pressure sleeve 52 are moved axially upward together in order to bring the contact surface 23 of the active part 2 into an electrically conductive connection with the contact surface 14 of the power supply tube 11.

Die Fig. 4 betrifft eine Anordnung, bei der die insgesamt mit 60 bezeichnete Klemmvorrichtung im wesentlichen der Klemmvorrichtung gemäss Fig. entspricht. Jedoch sind in der Fig. 4 näher erläutert die Ausbildung des Schafts 1 und die Steuerung der Klemmvorrichtung 60. Die Klemmvorrichtung 60 umfasst eine Klemmhülse 61, die mit einem Betätigungselement 62 verbunden ist. Die Klemmhülse 61 und das Betätigungselement 62 sind konzentrisch von einem Druckrohr 63 umgeben, an dessen Innenfläche im Bereich der Klemmhülse 61 eine konische Klemmfläche 64 angeformt ist. Durch eine entsprechende Relativbewegung zwischen der Klemmhülse 61 und der konischen Klemmfläche 64 werden die Backen der Klemmhülse 61 radial bewegt. Im vorliegenden Fall ist die Druckhülse 63 mit der konischen Klemmfläche 64 ortsfest angeordnet, indem die Druckhülse 63 unter Zwischenschaltung einer elektrischen Isolierung in das StromzuleitungsRohr 11 eingepasst ist.FIG. 4 relates to an arrangement in which the clamping device designated overall by 60 essentially corresponds to the clamping device according to FIG. However, the design of the shaft 1 and the control of the clamping device 60 are explained in more detail in FIG. 4. The clamping device 60 comprises a clamping sleeve 61 which is connected to an actuating element 62. The clamping sleeve 61 and the actuating element 62 are concentrically surrounded by a pressure tube 63, on the inner surface of which a conical clamping surface 64 is formed in the region of the clamping sleeve 61. The jaws of the clamping sleeve 61 are moved radially by a corresponding relative movement between the clamping sleeve 61 and the conical clamping surface 64. In the present case, the pressure sleeve 63 with the conical clamping surface 64 is arranged in a stationary manner in that the pressure sleeve 63 is fitted into the power supply pipe 11 with the interposition of electrical insulation.

Die Klemmhülse 61 wird axial über das Betätigungselement 62 bewegt. An dem der Klemmhülse 61 entgegengesetzten Ende des Betätigungselements 62 ist eine mechanisch-hydraulische Betätigungseinrichtung angeordnet, die insgesamt mit 100 bezeichnet ist. Diese besteht aus einem Zylinder 101, in dem ein Kolben 102 verschieblich gelagert ist. Dieser Kolben 102 ist mit der Zugstange 62 verbunden. Zwischen dem Kolben 102 und einem ortsfesten Anschlag des Zylinders 101 ist eine Feder 103 derart verspannt, dass diese stets das Betätigungselement 62 und mit dieser über die Klemmhülse 61 den Aktivteil 2 nach oben zu ziehen trachtet. Zum Lösen des Aktivteils 2 aus der Klemmvorrichtung 16 ist es lediglich notwendig, die obere Seite des Kolbens 102 mit einem über die Leitung 104 von einer nicht dargestellten Quelle zugeführten hydraulischen oder pneumatischen Medium zu beaufschlagen, wodurch das Betätigungselement 62 nach unten bewegt wird, so dass sich die Backen der Klemmhülse 61 radial nach aussen bewegen können. Dadurch kommt der Klemmzapfen 27 des Aktivteils 2 von der Klemmhülse 61 frei. In dieser Stellung der Anordnung kann der Klemmzapfen 27 eines unverbrauchten Aktivteils 2 in die Klemmhülse 61 eingeschoben werden. Danach wird die Anordnung zum Klemmen des neuen Aktivteils 2 wieder nach oben bewegt. Hierdurch gelangt auch die Kontaktfläche 23 des Aktivteils 2 in elektrisch leitende Anlage an der Kontaktfläche 14 des Stromzuleitungsrohrs 11.The clamping sleeve 61 is moved axially via the actuating element 62. At the end of the actuating element 62 opposite the clamping sleeve 61, a mechanical-hydraulic actuating device is arranged, which is denoted overall by 100. This consists of a cylinder 101 in which a piston 102 is slidably mounted. This piston 102 is connected to the pull rod 62. A spring 103 is clamped between the piston 102 and a stationary stop of the cylinder 101 in such a way that it always tries to pull the actuating element 62 and with it the active part 2 upwards via the clamping sleeve 61. To release the active part 2 from the clamping device 16, it is only necessary to apply a hydraulic or pneumatic medium to the upper side of the piston 102 via the line 104 from a source (not shown), as a result of which the actuating element 62 is moved downward, so that the jaws of the clamping sleeve 61 can move radially outwards. As a result, the clamping pin 27 of the active part 2 is released from the clamping sleeve 61. In this position of the arrangement, the clamping pin 27 of an unused active part 2 can be inserted into the clamping sleeve 61. Then the arrangement for clamping the new active part 2 is moved up again. As a result, the contact surface 23 of the active part 2 also comes into electrically conductive contact with the contact surface 14 of the power supply pipe 11.

Wie sich aus der Fig. 4 ferner ergibt, ist der in den Ofen eindringende Abschnitt des Schafts 1 aussenseitig durch eine Beschichtung 18 geschützt. Diese Beschichtung 18 besteht aus einem geeigneten Material, das den herrschenden thermischen und mechanischen Beanspruchungen widersteht.As can also be seen from FIG. 4, the portion of the shaft 1 penetrating into the furnace is protected on the outside by a coating 18. This coating 18 consists of a suitable material that withstands the prevailing thermal and mechanical stresses.

Die Elektrode wird in einer Durchführung im Deckel des Ofens durch eine am Schaft 1 angreifende Haltevorrichtung gehalten, die insgesamt mit 200 bezeichnet ist. Diese Halteeinrichtung 200 kann in beliebiger und deshalb nicht näher zu beschreibender Weise ausgebildet sein.The electrode is held in a feedthrough in the lid of the furnace by a holding device which acts on the shaft 1 and is designated overall by 200. This holding device 200 can be designed in any manner and therefore not to be described in more detail.

Die Fig. 5 zeigt die Klemmvorrichtung 60 gemäss Fig. 4 im Detail. Aus der Fig. 5 ergibt sich, dass die Druckhülse 63 selbst aus elektrisch isolierendem Material ausgebildet sein kann, so dass die Druckhülse 63 unmittelbar an dem Stromzuleitungsrohr anliegen kann. Die konische Klemmfläche 64 ist als separates Bauteil ausgebildet und auf geeignete Weise mit der Druckhülse 63 verbunden.FIG. 5 shows the clamping device 60 according to FIG. 4 in detail. 5 that the pressure sleeve 63 itself can be made of an electrically insulating material, so that the pressure sleeve 63 can rest directly on the power supply pipe. The conical clamping surface 64 is designed as a separate component and is connected in a suitable manner to the pressure sleeve 63.

Bei der Ausführungsform nach der Fig. 6 liegt die insgesamt mit 70 bezeichnete Klemmvorrichtung ebenfalls innerhalb des StromzuleitungsRohrs 11 des Schafts 1, greift aber im Gegensatz zu der vorstehend beschriebenen Konstruktion in ein entsprechend geformtes Sackloch 21 mit einer hinterschnittenen Klemmfläche 22 im Aktivteil 2 ein. Die Klemmvorrichtung 70 weist hierzu ein an seinem Ende pilzartig geformtes Betätigungselement 71 auf, das axial beweglich ist. Die Klemmhülse 72 befindet sich an dem unteren Ende eines ortsfesten Rohrs 73, das gegenüber dem Stromzuleitungs-Rohr 11 des Schafts 1 durch Zwischenschaltung einer Isolierung oder aufgrund der Ausbildung aus einem Isoliermaterial elektrisch getrennt ist. Beim Bewegen des Betätigungselements 71 nach oben werden die Klemmbacken der Klemmhülse 72 radial nach aussen bewegt, während beim Bewegen des Betätigungselements 71 nach unten die Klemmbacken der Klemmhülse 72 radial nach innen beweglich sind. In der radial nach innen bewegten Stellung der Klemmbacken der Klemmhülse 72 kann die Klemmvorrichtung 70 in das Sackloch 21 des Aktivteils 2 eingefahren werden. Danach wird das Betätigungselement 71 nach oben gefahren, so dass sich die Klemmbakken der Klemmhülse 72 nach aussen bewegen, wodurch die Klemmflächen 74 der Klemmhülse 72 die hinterschnittene Klemmfläche 22 des Sacklochs 21 des Aktivteils 2 hintergreifen. Danach wird das Betätigungselement 71 soweit nach oben gefahren, bis die Kontaktfläche 23 des Aktivteils 2 mit der Kontaktfläche 14 des StromzuleitungsRohrs 11 des Schafts 1 in Anlage gelangt, um auf diese Weise die elektrische Verbindung zwischen dem stromführenden Bauteil des Schafts 1 und dem Aktivteil 2 herzustellen.In the embodiment according to FIG. 6, the clamping device, which is designated as a whole by 70, also lies within the power supply tube 11 of the shaft 1, but, in contrast to the construction described above, engages in a correspondingly shaped blind hole 21 with an undercut clamping surface 22 in the active part 2. For this purpose, the clamping device 70 has an actuating element 71 which is shaped like a mushroom at its end and is axially movable. The clamping sleeve 72 is located at the lower end of a stationary tube 73, which is electrically isolated from the power supply tube 11 of the shaft 1 by the interposition of insulation or due to the formation of an insulating material. When the actuating element 71 is moved upwards, the clamping jaws of the clamping sleeve 72 are moved radially outwards, while when the actuating element 71 is moved downwards, the clamping jaws of the clamping sleeve 72 are movable radially inwards. In the radially inwardly moved position of the clamping jaws of the clamping sleeve 72, the clamping device 70 can be inserted into the blind hole 21 of the active part 2. The actuating element 71 is then moved upward, so that the clamping jaws of the clamping sleeve 72 move outwards, as a result of which the clamping surfaces 74 of the clamping sleeve 72 engage behind the undercut clamping surface 22 of the blind hole 21 of the active part 2. Thereafter, the actuating element 71 is moved upwards until the contact surface 23 of the active part 2 comes into contact with the contact surface 14 of the power supply tube 11 of the shaft 1, in order in this way to establish the electrical connection between the current-carrying component of the shaft 1 and the active part 2 .

Bei den beschriebenen Klemmvorrichtungen ist das Hauptaugenmerk darauf gerichtet, dass die von der jeweiligen Klemmvorrichtung unmittelbar auf das Aktivteil ausgeübte Klemmkraft das Material des Aktivteils im wesentlichen auf Druck beansprucht. Natürlich wird in üblicher Weise der Aktivteil aufgrund seines Eigengewichts auf Zug beansprucht.In the described clamping devices, the main focus is on the fact that the the clamping force exerted by the respective clamping device directly on the active part essentially stresses the material of the active part. Of course, the active part is subjected to tension due to its own weight in the usual way.

Die stromführenden Bauteile der Anordnung bestehen aus einem geeigneten elektrisch leitenden Werkstoff, wie z. B. Kupfer bzw. einer entsprechenden Metallegierung. Sowohl die stromführenden als auch die anderen Bauteile des Schafts werden entsprechend gekühlt und durch Beschichtungen gegen thermische und mechanische Überbeanspruchungen gesichert. Die angewendeten Gleichführungen zwischen den einzelnen Bauteilen können mit Grafit oder ähnlichen hochtemperaturfesten Schmiermaterialien beschichtet oder belegt sein, um gute Gleitverhältnisse auch bei hohen Temperaturen und starken mechanischen Beanspruchungen zu gewährleisten. Die angesprochenen Beschichtungen bestehen zweckmässigerweise aus hochtemperaturfesten, keramischen Materialien. Die Aktivteile bestehen in erster Linie aus Grafit.The current-carrying components of the arrangement consist of a suitable electrically conductive material, such as. B. copper or a corresponding metal alloy. Both the current-carrying and the other components of the shaft are cooled accordingly and protected against thermal and mechanical overloading by means of coatings. The parallel guides used between the individual components can be coated or coated with graphite or similar high-temperature-resistant lubricating materials in order to ensure good sliding conditions even at high temperatures and high mechanical loads. The coatings in question expediently consist of high-temperature-resistant, ceramic materials. The active parts consist primarily of graphite.

Claims (25)

1. An electrode for arc furnaces, in particular for the production of electrosteel, comprising a metallic, liquid-cooled upper shaft and an exchangeable, lower active part of consumable material, in particular graphite, whereby the connection between the upper shaft and the active part is effected by a clamping means (40; 50; 60; 70; 300) comprising clamping jaws (42; 51; 61; 72; 302), said clamping means holding the upper shaft and the active part to one another, characterized in that tensioning means (41; 52; 62; 71; 301) are provided by which said clamping jaws may be moved in axial direction, thereby pulling the active part towards the metal shaft, and in thatthe clamping jaws comprise bevelled surfaces which, upon movement or biassing of said clamping jaws in axial direction create radial components of movements or forces, by which said active part may be clamped.
2. Electrode according to claim 1, characterized in that the clamping means is mechanically actuated.
3. Electrode according to claim 1, characterized in that the clamping means is pneumatically or hydraulically actuated.
4. Electrode according to claim 1, characterized in that the clamping force is generated by the active portion's proper weight.
5. Electrode according to one of the preceding claims, characterized in that the clamping means has a separate cooling system or is connected to the cooling system of said shaft.
6. Electrode according to one or more of the preceding claims, characterized in that the clamping means clamps the active part at its top portion from inside and/or from outside.
7. Electrode according to one or more of the preceding claims, characterized in that the active portion is fitted to the clamping means by the formation of matching parts, apertures, recesses and grooves.
8. Electrode according to one of the preceding claims, characterized in that the clamping means comprises a collet, whose outer, operating surface which is in contact with the active part is expandable by a pressure means.
9. Electrode according to claim 8, characterized in that the clamping means comprises a collet, whose operating inner surface which is in contact with the active part is constrictable by a pressure means.
10. Electrode according to claim 8 or 9, characterized in that the collet is made in one piece and has at least one longitudinal slit.
11. Electrode according to claim 8 or 9, characterized in that the collet is composed of a number of segments.
12. Electrode according to one of the preceding claims, characterized in that the clamping means (40) grips the active portion (2) at its peripheral surface, in that the current-conducting-component (11) of the shaft (1) is arranged within the collet (42) of the clamping means (40) and in that the collet (42) is surrounded by a tube (43), the inner walls of which comprise bevelled surfaces (43a) cooperating with bevelled surfaces (42a) on said collet (42).
13. Electrode according to one of the preceding claims, characterized in that the clamping means (50; 60) are located within the current-conducting component (11) of shaft (1) and in that the collet (51; 61) grips the active portion (2) at a clamping cone (27) mounted thereon.
14. Electrode according to claim 13, characterized in that the pressure means comprises a pressure collet (52,; 63), the conical inner surface (53; 64) of which abuts on the corresponding conical outer surface of the collet (51; 61).
15. Electrode according to one of the preceding claims, characterized in that the pressure arrangement comprises a mushroom-shaped actuating element (71) having a conical outer surface abutting on the corresponding conical inner surface of the collet (72).
16. Electrode according to one of the preceding claims, characterized in that the operating outer or inner surface of the collet is cylindrical to form a positive connection with the active portion.
17. Electrode according to one of the preceding claims, characterized in that the operating inner or outer surface of the collet is conical to form a positive and a force-locking connection.
18. Electrode according to one of the preceding claims, characterized in that the operating outer or inner surface of said collet comprises projections to form an additional positive connection to the force-locking connection.
19. Electrode according to claim 18, characterized in that the projections are radially resiliently mounted to form a snap coupling when the active portion is thrust onto said collet.
20. Electrode according to claim 19, characterized in that the projections are spring- biassed.
21. Electrode according to claim 13, characterized in that the pressure means of the collet (83) has axially movable wedges (84) actuated by hydraulic or pneumatic means.
22. Electrode according to one of the preceding claims, in which the clamping means surrounds the current-conducting component of the shaft, characterized in that said component is a solid bar
(15) which is connected at its lower end to a contact plate (16).
23. Electrode according to claim 22, characterized in that the outer diameter of the contact plate (16) corresponds approximately to the outer diameter of said active portion (2).
24. Electrode according to one of the preceding claims, in which the current-conducting component of the shaft is a tube, the clamping means being arranged within said tube, characterized in that the outer diameter of the tube (11) corresponds approximately to the outer diameter of said active portion (2).
EP80107523A 1980-12-02 1980-12-02 Arc furnaces electrode Expired EP0053200B1 (en)

Priority Applications (24)

Application Number Priority Date Filing Date Title
EP80107523A EP0053200B1 (en) 1980-12-02 1980-12-02 Arc furnaces electrode
AT80107523T ATE22383T1 (en) 1980-12-02 1980-12-02 ELECTRODE FOR ARC MELTING FURNACES.
DE8080107523T DE3071765D1 (en) 1980-12-02 1980-12-02 Arc furnaces electrode
ZA817978A ZA817978B (en) 1980-12-02 1981-11-17 Electrode for electric arc furnaces
CA000390225A CA1173482A (en) 1980-12-02 1981-11-17 Electrode for electric arc furnaces
FI813636A FI813636L (en) 1980-12-02 1981-11-17 ELEKTROD FOER LJUSBAOGSSMAELTUGN
NZ199015A NZ199015A (en) 1980-12-02 1981-11-20 Arc furnace electrode:active portion attachment
AU77694/81A AU546162B2 (en) 1980-12-02 1981-11-20 Electrode for arc furnace
IN1319/CAL/81A IN155086B (en) 1980-12-02 1981-11-24
KR8104570A KR870000098B1 (en) 1980-12-02 1981-11-26 Electrode for electric arc furnaces
HU813541A HU192078B (en) 1980-12-02 1981-11-26 Electrode for arc furnaces
GR66642A GR77313B (en) 1980-12-02 1981-11-27
YU02797/81A YU279781A (en) 1980-12-02 1981-11-27 Electrode for electric arc furnaces
PT74061A PT74061B (en) 1980-12-02 1981-11-30 ELECTRODE FOR LIGHT BOW MELTING OVEN
US06/326,068 US4481500A (en) 1980-12-02 1981-11-30 Electrode for electric arc furnaces
ES508108A ES8301088A1 (en) 1980-12-02 1981-12-01 Arc furnaces electrode.
DD81235287A DD208283A5 (en) 1980-12-02 1981-12-01 ELECTRODE FOR LIGHT BOW MELTING OVEN
NO814093A NO814093L (en) 1980-12-02 1981-12-01 ELECTRO OVEN ELECTRODE
TR21916A TR21916A (en) 1980-12-02 1981-12-01 ELECTRODE FOR ELECTRIC ARC FURNACES
DK532781A DK532781A (en) 1980-12-02 1981-12-01 ELECTRODE FOR ARM Melting Ovens
JP56194313A JPS57119493A (en) 1980-12-02 1981-12-02 Electrode for arc furnace
PL23405981A PL234059A1 (en) 1980-12-02 1981-12-02
SU813360407A SU1093266A3 (en) 1980-12-02 1981-12-02 Electrode holder for arc furnace
GB8136351A GB2092418A (en) 1980-12-02 1981-12-02 Electrode for an arc furnace

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP80107523A EP0053200B1 (en) 1980-12-02 1980-12-02 Arc furnaces electrode

Publications (2)

Publication Number Publication Date
EP0053200A1 EP0053200A1 (en) 1982-06-09
EP0053200B1 true EP0053200B1 (en) 1986-09-17

Family

ID=8186916

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80107523A Expired EP0053200B1 (en) 1980-12-02 1980-12-02 Arc furnaces electrode

Country Status (24)

Country Link
US (1) US4481500A (en)
EP (1) EP0053200B1 (en)
JP (1) JPS57119493A (en)
KR (1) KR870000098B1 (en)
AT (1) ATE22383T1 (en)
AU (1) AU546162B2 (en)
CA (1) CA1173482A (en)
DD (1) DD208283A5 (en)
DE (1) DE3071765D1 (en)
DK (1) DK532781A (en)
ES (1) ES8301088A1 (en)
FI (1) FI813636L (en)
GB (1) GB2092418A (en)
GR (1) GR77313B (en)
HU (1) HU192078B (en)
IN (1) IN155086B (en)
NO (1) NO814093L (en)
NZ (1) NZ199015A (en)
PL (1) PL234059A1 (en)
PT (1) PT74061B (en)
SU (1) SU1093266A3 (en)
TR (1) TR21916A (en)
YU (1) YU279781A (en)
ZA (1) ZA817978B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3265147D1 (en) * 1981-03-24 1985-09-12 Krupp Gmbh High-current conductor system for electric furnaces
DE3319389C2 (en) * 1983-05-26 1987-03-05 Mannesmann AG, 4000 Düsseldorf Electrode for arc furnaces
DE3620203A1 (en) * 1986-06-16 1987-12-17 Riedhammer Ludwig Gmbh HEATING ELEMENT
RU2230440C2 (en) * 2001-02-01 2004-06-10 Хлопонин Виктор Николаевич Electrode and method for its cooling in the course of electric furnace ope ration
DE102010048647A1 (en) * 2010-10-15 2012-01-19 Fuchs Technology Holding Ag Gripper for holding electrode of electric arc furnace, has several claws engaged with claw engaging element at engagement position in which distance between free end and longitudinal axis of base is larger than half of element diameter
KR101293870B1 (en) * 2012-04-27 2013-08-07 강성인 Dc arc furnace for melting mineral

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE92811C (en) *
US824153A (en) * 1904-05-03 1906-06-26 Willson Aluminum Company Carbon-holder for electric furnaces.
FR421991A (en) * 1910-10-29 1911-03-09 Henri Auguste Georges Cinille Improvements to the electrodes of electric ovens and the means of guiding them in the walls of the ovens
FR480802A (en) * 1915-05-03 1916-09-28 Fr Des Electrodes Soc Device for connecting carbon electrodes end to end
DE322889C (en) * 1918-07-05 1920-07-10 Siemens & Halske Akt Ges Electrode holder for electric furnaces
FR628050A (en) * 1925-12-28 1927-10-17 Ig Farbenindustrie Ag Mount for closed electric oven electrodes
FR877771A (en) * 1941-01-09 1942-12-16 Device for mounting electrodes for electric ovens
DE1120038B (en) * 1953-12-05 1961-12-21 Elektrokemisk As Socket for continuously burning electrodes
DE1128581B (en) * 1957-07-26 1962-04-26 Mc Graw Edison Co Power operated holding and feeding device for furnace electrodes
US3046319A (en) * 1960-01-20 1962-07-24 Allegheny Ludlum Steel Electrode stub clamp
DE1440345A1 (en) * 1960-12-27 1968-12-19 Deutsche Edelstahlwerke Ag Coupling device on electric arc furnaces with self-consuming electrode
US3293347A (en) * 1965-10-24 1966-12-20 Consarc Corp Electrode stub clamp
US3526699A (en) * 1969-03-03 1970-09-01 Lombard Corp Apparatus for connecting ram to electrode
FR2176546A1 (en) * 1972-03-23 1973-11-02 Siderurgie Fse Inst Rech Composite furnace electrode - esp for steel prodn
US4145564A (en) * 1978-01-30 1979-03-20 Andrew Dennie J Non-consumable electrode with replaceable graphite tip

Also Published As

Publication number Publication date
ATE22383T1 (en) 1986-10-15
JPS57119493A (en) 1982-07-24
TR21916A (en) 1985-11-15
IN155086B (en) 1984-12-29
ES508108A0 (en) 1982-11-16
PT74061B (en) 1983-05-11
FI813636L (en) 1982-06-03
HU192078B (en) 1987-05-28
NZ199015A (en) 1985-07-12
CA1173482A (en) 1984-08-28
DK532781A (en) 1982-06-03
AU546162B2 (en) 1985-08-15
YU279781A (en) 1983-10-31
KR870000098B1 (en) 1987-02-10
SU1093266A3 (en) 1984-05-15
DD208283A5 (en) 1984-03-28
AU7769481A (en) 1982-06-10
PT74061A (en) 1981-12-01
DE3071765D1 (en) 1986-10-23
GR77313B (en) 1984-09-11
NO814093L (en) 1982-06-03
US4481500A (en) 1984-11-06
EP0053200A1 (en) 1982-06-09
ZA817978B (en) 1982-10-27
ES8301088A1 (en) 1982-11-16
PL234059A1 (en) 1982-07-19
GB2092418A (en) 1982-08-11
KR830007888A (en) 1983-11-07

Similar Documents

Publication Publication Date Title
EP0061612B1 (en) High-current conductor system for electric furnaces
EP0391262B1 (en) Clamping device to clamp axially a toolhead on a machine-tool spindle
EP0053200B1 (en) Arc furnaces electrode
EP1385664B1 (en) Method and device for machining annular-shaped workpieces
DE69314749T2 (en) Electrode connection point for self-centering
EP3964332A1 (en) Clamping device
DE3304099C2 (en)
EP0417613A1 (en) Device for coupling two parts of machine tools
DE69512732T2 (en) Device for holding a self-baking composite electrode of an arc furnace
EP0071107A1 (en) Arrangement for connecting a graphite electrode to a permanent electrode of an electric furnace
DE3339127A1 (en) GRIPING DEVICE FOR RODS INSERTIBLE INTO THE STITCH HOLE OF METALLURGICAL OFENS, IN PARTICULAR TAPPING RODS
DE3144926C2 (en) Graphite electrode for use in an electrode holder of an electric furnace
DE3426066C2 (en) Clamping device on an electric welding machine
DE3100921A1 (en) ELECTRODE, ESPECIALLY FOR ARC OVENS OR MELTFLOW ELECTROLYSIS
DE102019217433A1 (en) Electrode holding device and system for repositioning an electrode in a metallurgical furnace
DE1293360B (en) Device for holding and powering a consumable electrode in an arc furnace
WO2010081888A1 (en) Graphite electrode having an electrical connector piece
DE3700841A1 (en) CLUTCH ELEMENT, IN PARTICULAR FOR FORCE AND FORM-CONNECTIVE CONNECTION OF A TOOL HEAD TO A TOOL HOLDER
DE909756C (en) Bracket and power supply for electric ovens and heating devices
DE1048651B (en)
EP1501643A1 (en) Device and method for mounting a roll ring onto a shaft of a rolling stand
DE2642411C2 (en) Cable lug for electrical cables
EP4213294A1 (en) Supporting element for transfer of components
DE102004043627A1 (en) Method for welding bolts to workpieces comprises melting mass of welding material between them and moving relative to each other to produce bond, melting of welding material being carried out by setting up arc between bolt and workpiece
AT221335B (en) Die for pressing out several full profiles at the same time

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI NL SE

ITCL It: translation for ep claims filed

Representative=s name: PROF. FRANCO CICOGNA

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ARC TECHNOLOGIES SYSTEMS, LTD.

TCNL Nl: translation of patent claims filed
17P Request for examination filed

Effective date: 19821111

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE FR GB IT LI NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19860917

Ref country code: BE

Effective date: 19860917

REF Corresponds to:

Ref document number: 22383

Country of ref document: AT

Date of ref document: 19861015

Kind code of ref document: T

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19860930

REF Corresponds to:

Ref document number: 3071765

Country of ref document: DE

Date of ref document: 19861023

ITF It: translation for a ep patent filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Effective date: 19861202

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19861231

Ref country code: CH

Effective date: 19861231

ET Fr: translation filed
NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19881202

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19890831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19890901

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST