Abstract: A method for forming a protective antioxidative barrier on the furnace electrodes using a chemically altered cooling liquid containing an antioxidant additive. This method can be applied to electrodes used in electric arc furnaces and ladle metallurgy furnaces. The method can involve spraying the cooling liquid onto the electrode, thereby forming the protective antioxidative barrier and reducing the oxidation of the electrode.

Abstract: In a method for determining a state variable of an electric arc furnace, especially for determining the level of the foamed slag (15) in a furnace, the energy supplied to the furnace is determined with the aid of at least one electric sensor while solid-borne noise is measured in the form of oscillations on the furnace. The state variable is determined by a transfer function which is determined by evaluating the measured oscillations and evaluating measured data of the electric sensor. The state of the foamed slag level can thus be reliably recognized and be monitored over time. The foamed slag level is decisive for the effectiveness with which energy is fed into the furnace. Furthermore, losses caused by radiation are reduced by covering the arc with the foamed slag. The improved measuring method allows the foamed slag level to be automatically controlled or regulated in a reliable manner.

Abstract: The present invention provides a shaft high temperature continuous graphitizing furnace comprising a furnace body comprising a feeding inlet and a discharging outlet, an electrode pair, a cooling system and a discharging device; the furnace body is designed to be a shaft cylindrical structure; the electrode pair is provided within the furnace body and comprise an upper electrode and a lower electrode, the upper electrode is located below the feeding inlet, and an umbrella or cone table shape electric field having a lower cross section area greater than its upper cross section area arises between the upper electrode and eh lower electrode; and the cooling system is located between the lower electrode and the discharging outlet.

Abstract: A sealing device is arranged around a rod electrode extending vertically through an aperture made in the ceiling of an arc furnace and being vertically movable inside the furnace to prevent the access of gases from the furnace through the aperture to the atmosphere, and on the other hand to prevent air from flowing from the atmosphere into the furnace. The sealing device comprises a gas distribution chamber provided with an inlet channel for feeding essentially passive gas, such as nitrogen or air, into the gas distribution chamber. The sealing device also includes a slit nozzle encasing the electrode, through which nozzle a gas jet is arranged to be discharged from the gas distribution chamber towards the electrode in a direction that is at an angle with respect to the horizontal plane and has a slightly upwards inclined orientation, and that is, with respect to the furnace interior, pointed outwardly, so that the sealing is carried out owing to the effect of the created stagnation pressure.

Abstract: A roof system for an electric arc furnace includes a skew removably attached to the electric arc furnace, a lining of refractory material affixed to the skew, and a delta composed of a refractory material. The delta has at least one aperture capable of receiving an electrode. The delta fits onto and is supported by the refractory lining that is affixed to the skew.

Abstract: A method for treating spheroidal graphite iron includes the step: pouring molten spheroidal graphite iron into a pouring electrical furnace (1); covering the molten spheroidal graphite iron (5) with alkali slag (6) which is melted at high temperature and rich in alkali earth metal ion, rare earth metal ion, or mixture of them; connecting the molten spheroidal graphite iron (5) with the negative pole of the direct current source by one pole (7); connecting the alkali slag (6) with the positive pole of the direct current source by another pole (4), treating the molten spheroidal graphite iron (5) with the alkali slag (6) which is used as electrolyte. The method can prevent the spheroidized fading velocity of the spheroidal graphite iron. The pouring electrical furnace can be used for treating the molten spheroidal graphite iron.

Abstract: In various embodiments, an electrode has a shaft extending from an electrode head and a cooling passage extending from an open end disposed at an attachment end of the shaft to a closed end disposed within the electrode head.

Abstract: A graphite electrode joint, where the male tang has a tang factor, defined as the ratio of male tang length to electrode diameter, of at least about 0.60.

Abstract: Adapter device for composite electrodes having an auxiliary reactance function on electric arc furnaces, the furnace being able to be of a type fed with direct current or alternating current and comprising at least one secondary supply circuit which connects a transformer (13) to one or more electrode-holder arms (16), the adapter comprising a hollow cylindrical metallic body (21) associated with the relative electrode-holder arm (16) and directed towards the inside of the furnace, the metallic body (21) being connected at its lower end to a graphite segment (24), directed towards the bath of molten metal, at least part of the the adapter (20) including a conductive portion (30) which is made of a highly conductive material and is solidly associated with the metallic body (21) and is dimensioned according to the desired value of overall reactance of the secondary circuit of the furnace.

Abstract: Cooling system for cathodes, or electrodes, (11) in Direct Current electric arc furnaces, the cathodes (11) comprising a lower consumable graphite part (11a), from which the electric arc is sparked, associated at the upper part with a hollow metallic part (11b) by means of a joint (13), inside the metallic part (11b) there being included a closed cooling circuit (19) with water or other similar cooling fluid, defining an area of evaporation (17) arranged substantially in cooperation with the lower end of the metallic part (11b) and an area of condensation (18) arranged in cooperation with a desired upper area of the metallic part (11b), the area of condensation (18) cooperating with a heat exchanger (15) associated with the outer wall of the metallic part (11b), there also being included an ascending channel (14) for the steam (19a) from the evaporation area (17) to the area of condensation (18) and at least a descending channel (16) whereby the condensation descends, under force of gravity, from the area of

Abstract: An electric arc furnace having a partially insulated electrode produces molten metal such as foundry iron from an iron source where little or no slag is produced. The furnace includes at least one insulated electrode assembly for immersing deep into the metal charge. The electrode assembly has an electrically conducting member coupled to an electrode. The electrode has a coupling member at the upper end for coupling with the electrically conducting member and a coupling member at the lower end for coupling with an adjacent electrode to form an electrode column. The coupling members can be an internally threaded recess in the ends thereof. An externally threaded coupling member can be threaded into the recesses of the electrodes for coupling two or more electrodes together.

Abstract: System for connection of pneumatic and/or hydraulic hoses (11) on composite electrodes (12) for arc furnaces, the electrodes (12) comprising, at least one hollow adapter (13) associated at their lower part with a replaceable graphite element (14), the electrode (12) cooperating with an electrode-holder arm (15) and being displaceable axially in relation to that electrode-holder arm (15), the hoses (11) being associated at one end with a first connection assembly (18a) associated with a support (17), the adapter (13) including a solidly attached second connection assembly (18b) mating functionally with the first connection assembly (18a), the first (18a) and second (18b) connection assemblies comprising mating connecting elements (19a, 19b) equipped with elements to interrupt the flow of the fluid which can be temporally actuated, the a support (17) associated with the first connection assembly (18a) having a first inactive position temporally solid with the electrode-holder arm (15) and a second working posit

Abstract: A secondary circuit having a variable impedance for electric arc furnaces of a type working with alternating current, which is associated with a transformer (11) is disclosed. A secondary circuit comprises at least one rigid connection (12) connected to the outputs (16) of the transformer (11), flexible cables (13) connected through rigid connection elements (29, 129) at first end to the rigid connection (12) and at the other end to specific electrodes (15). At least one branch of the secondary circuit (10) corresponds to a specific phase including at least one of the respective rigid components (12, 17, 29, 129) having at least two parts reciprocally positionable in an adjustable manner according to the required value of overall reactance of the specific branch of the secondary circuit (10) comprising that rigid component (12, 17, 29, 129).

Abstract: A support for a melting electrode used in a glass melting bath. The support includes concentric tubes which provide for the circulation of a cooling fluid within the support. A current is provided through the outer tube to the electrode. The surface of the outer tube is electrically insulated and may be protected by a second cooling system outside the electrical insulation.

Abstract: A nonconsumable water-cooled electrode for electric metal smelting furnaces which includes inner and outer concentric steel tubes defining an annular space therebetween through which cooling water may be passed. A tungsten tip is attached to the tubes at their lower ends. Electric current is introduced through a plurality of copper bars attached to the tungsten tip at one end and to a copper plate at the upper end. The copper plate is adapted to attach the electrode to a suitable electrode carrier. A central pipe is provided through which an inert gas, such as argon, may be passed through the electrode.

Abstract: The electric connection device comprises an electrode (5), a sleeve (19) mounted around a projecting end part (8) of the electrode (5), and an arrangement for cooling the sleeve (19) with a cooling fluid comprising at least one system (20, 20') of nozzles (21) spraying cooling fluid onto the outer surface of the sleeve (19).

Abstract: The electric furnace operating cycle time is substantially reduced by directing water into the porous pack of carbonaceous material surrounding the electrodes at a water rate adjusted to maximize vaporization of water into steam within the porous pack while allowing the steam to escape without contacting the electrodes.

Abstract: A safety flow stopper in a water-cooled electric arc furnace electrode comprises a bob 16 held in place above a valve seat 12 by a release pin 17 resting on the bottom of the cavity in the nipple 20. If the electrode fails the release pin will no longer support the bob which will seat in the valve seat, shutting off the coolant flow and averting an explosion in the furnace.

Abstract: The invention is a novel Soderberg electrode paste composition. The composition is a mixture comprising carbonaceous aggregate, novolac resin binder, plasticizer and optionally hexamethylenetetramine. The novolac resin of the binder has a melting point of at least 100.degree. C. and a free phenol content of not more than 4% by weight based on the weight of novolac resin solids. The residual coking value of the composition of the invention is at least as great as the minimum preferred coking value of traditional Soderberg pastes which are based on coal tar pitch binder.

Abstract: An inert composite electrode, such as an anode, for molten salt electrolysis consists of an active part in the form of a plurality of bar-shaped active elements, in particular of ceramic oxide, which are arranged with their longitudinal axes mutually parallel and in mutually aligned groups, an electrode holder which comprises a current-conducting plate, with one main surface of which the active elements are in firm contact with their end surfaces, and a joining arrangement which joins the active elements together in groups and holds them in contact with the plate.

Abstract: In a water cooled electrode assembly for an electric arc steel furnace, a water trap manifold 14 integral with the head assembly at the upper end of said electrode.

Abstract: A hollow arc furnace electrode comprises a central channel formed in its upper part as a tube and in its lower part as a passage extending through a graphite tip of the electrode. A metallic electrode portion is arranged around the central tube above the tip, which electrode portion is provided with channels for liquid coolant flow.

Abstract: A coherent particulate composite is formed by blending particulate material with a binder containing lignosulfonate and urea.

Abstract: Temperature-resistant materials as protective coat for the metal shaft of combination electrodes for the electric steel production, constituting a compound material comprising a carbon share, which contains graphitic structural elements, and a share with at least one ceramic component. The protective elements, which are made of these materials, are characterized by long service times, little susceptibility to unwanted adhesive matter, and good emergency running properties.

Abstract: A water-cooled electrode for an electric arc furnace is fitted with a copper nipple 10, increased surface area through fluting or drilled or threaded passages for vastly improved cooling, joining the water-cooled and graphite portions of the electrode.

Abstract: An automatic facility for the connection of combination arc electrodes to a cooling water circuit, comprising a cooling water coupling device (17) mounted on the supporting arm (3) of the electrode, which on the one hand is connected to cooling water ducts (15, 15') and which on the other hand has openings (19, 19', 19") into which the free ends (21, 21') of cooling water guides (7,8) may be inserted, which are connected to the heat exchanger (1) of the combination electrode. By means of a fixing device (11, 11') mounted e.g. on the ring flange (9) of a contact device which is axially movable on the electrode, these ends of the cooling water guides may be positioned in such a way that, when slipping the electrode down through the clamping device (4) of the supporting arm (3) of the electrode, the free ends (21, 21') automatically assume an angle orientation which makes it possible to neatly insert these ends into the openings (19, 19') of the cooling water coupling device (17).

Abstract: An electrode for an electric arc furnace includes a cooled metal sheath covered with a refractory protective jacket. A plurality of refractory anchors are fixed to the exterior of the sheath, and the anchors are spaced from each other. The protective jacket includes an undercoat on the exterior of the sheath and a protective layer over the undercoat and extending between the anchors. The protective layer is formed of a refractory material such that, at the operating temperature of the electrode, the protective layer has an inner zone which is thermoplastic and an outer zone which is rigid or which is a high-viscosity melting phase.

Abstract: In an electrode for electric arc furnaces, having a water-cooled metallic electrode holder and a consumable section connected to the electrode holder by means of a threaded nipple, the electrode holder having a protective jacket made up of rings. A disc positioned between the consumble section and the electrode holder which, in the event of a fracture of the consumable section, remains attached to the electrode holder for protection against electric arc strike.

Abstract: Improvements on a DC plasma jet generator for emission spectrochemical analysis wherein two anode blocks and one cathode block are positioned in an inverted Y shape, and each of the anode blocks has a cylinder, a piston, an an anode received by a recess in the end of the piston. Each anode can be secured in the recess at the end of the piston in the corresponding anode block by magnetic force. Each of the anode and cathode blocks is pivotable so that the associated electrode attached to each block can be fixed upright with the free end thereof directed upward. This means that the electrodes can be replaced easily as well as speedily by remote control using manipulators.

Abstract: An upper and a lower electrode section are mechanically interconnected through a nipple threaded into the lower electrode, as well as into a receiver on a tension rod pulling the nipple up, and thereby the lower electrode is urged against the front end of a twin wall upper electrode. The receiver is for its most parts surrounded by a twin wall sleeve passed through by cooling fluid and being suitably held within the upper electrode for axial displacement but bars intermittent contact with the receiver to obtain cooling thereof as well as of the connecting nipple.

Abstract: An arc electrode assembly comprises a water-cooled metal shaft and a consumable active portion, being interconnected by means of a screw nipple. The metal shaft is surrounded below its clamping area by a protective jacket being detachably arranged about the metal shaft. Between the jacket and the metal shaft a layer of electrically insulating refractory material is arranged which is cooled by the cooling system of the jacket. The protective jacket comprises at least one steel tube which is provided for the passage of a cooling medium. The steel pipe(s) may additionally be surrounded by refractory or slag material or may directly be embedded into such material.

Abstract: In a fluid-cooled clamp member (1) of a composite electrode (2) of an electric arc furnace, disposed in the flow path (13) for the coolant is a shut-off device (14) which is biassed in the closure direction, having an actuating member (15) by means of which the shut-off device (14) is put into the open condition in opposition to the biassing force, when a replaceable lower portion (2) of the composite electrode, which is subject to burning away, is screwed on. In the event of fracture of the lower portion in the region of the nipple (5), the flow path (13) is closed off by the actuating member (15) being released. The screwthreaded nipple is additionally protected by means of a protective cap which is screwed on to the screwthreaded nipple, the cap having an external screwthread corresponding to the internal screwthread of the lower portion (2).

Abstract: This invention concerns apparatus for selectively connecting an electrode of an electric arc furnace to a source of cooling fluid. The apparatus includes a coupling having passageways extending therethrough for the flow of cooling fluid and comprises at least two separable sections, one such section being connected to receive cooling fluid from the source and the other to convey such cooling fluid to the electrode when coupled to the said one section. Guide means are provided to guide one separable section into close proximity to the other section and to clamp the assembled sections together to connect the electrode to the source of cooling fluid.

Abstract: A system which permits the measurement, during operation, of the arc voltage electrodes having an upper metal portion (4) cooled by circulating water. The system employs an electrical instrumentation-cable (16) attached to a piece (5) for fixing the graphite consumable portion (3) of the electrode. This cable runs along the axis of the metal portion (4) and then inside one of the water-supply pipes (11), terminating at an electronic box (14) which converts the incoming measurement signal into a light wave.

Abstract: An electrode for arc furnaces, comprising a metallic water-cooled upper section and a consumable, replaceable lower section, interconnected by means of a threaded nipple or the like. At least one light-receiving element is positioned in a zone associated with the interconnection of the cooled metal shaft and the consumable section. A light signal falling on the light-receiving element where the consumable section is in absence, is passed in a suitable manner via a light wave guide to a furnace control which activates a safety system.

Abstract: A composite water-cooled electrode for electric arc steel furnaces comprises a tubular graphite body held in compression by means of tension stressed internal water supply pipe located between a metal header at one end and a hollow metal nipple at the other end of the electrode.

Abstract: An electrode for electric arc furnaces, comprising an upper, metallic, water-cooled section and a lower section of consumable material, such as graphite, is held in its given position by means of an electrode support arm 1,2. The connection elements for electric power and liquid coolant 12, 6, 25 are integrated in the electrode support arm and are designed as plug connections.

Abstract: The electrode has a durable upper part and a consumable tip. A plurality of copper tubes extend through the upper part. The connection to the consumable tip is by means of an intermediate plate and a nipple, the latter containing ducts for the connection of the copper tubes. At the upper end of the electrode, the copper tubes are serially interconnected by tube bends and at their lower end by ducts in the nipple.

Abstract: A graphite nipple projecting from one end of a graphite electrode portion of the type used in an electric furnace has a supporting face for receiving a non-graphite portion of a clamping device in shape-locking engagement for holding the electrode for use. It also has a conventional screw-thread surface for joining the nipple to another electrode portion for extending the electrode. The supporting face does not alter the conventional screw-thread surface arrangement for joining electrode portions so that specially-shaped and thus costly electrode-supporting nipples are not required in addition to the conventionally-shaped nipples for joining electrode portions, and a graphite screw-thread does not have to be unscrewed for the same, which unscrewing frequently broke the nipple or electrode portion.

Abstract: A composite electric arc furnace electrode comprises a heavy-walled tubular graphite body with a sealed inner bore, a hollow nipple, a central coolant supply pipe, and a metal header assembly. If the unit fails, it is disassembled, a new graphite main tube assembled with the metal parts, and the graphite tube consumed in the normal fashion as a tip electrode.

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.

Abstract: An electrode for fusion electrolysis comprising an upper portion (5) of metal and a replaceable lower portion (6) of self-consuming or of slowly self-consuming material which are interconnected by a screw-nipple (1) or the like, whereby the upper portion may have a cooling device with a feed duct (2) and a return duct (3) and the upper portion (5) has at least partially and preferably in its lower region a protective covering, whereby this covering is a detachably surmounted sheath (4) of mechanically resistant material, which is electrically conductive. The sheath can be sub-divided into individual segments, while the design of screw-mounted units with internal recesses for the acceptance of resilient, electrically conductive materials reveals especially favorable properties.

Abstract: Electrodes for arc furnaces comprising a top portion (5) of metal and a replaceable bottom portion (6) of material which is only slowly consumable, being substantially cylindrical shape and the portions being interconnected by means of a screw nipple (1) or the like and the top portion has a liquid cooling device with a header duct (2) and a return duct (3) and the top portion (5) is advantageously protected in the bottom region thereof by means of an insulating coating of high temperature stability representing a detachably surmountable moulding. An electrically conductive intermediate layer of high temperature stability can be provided between the insulating moulding and the top portion. The electrodes are only slightly trouble prone, have emergency operating properties, have a high mechanical stressability and are easy to repair.

Abstract: An electrode for arc furnaces comprising a top portion of metal and a replaceable bottom portion of a material which, when appropriate, is only slowly consumed having a substantially cylindrical shape and being joined each to the other by a screwmounting, for example by means of a screw nipple or the like. The top portion includes a liquid cooling device or means with a header and a return duct, and an insulating coating of high temperature stability. An inner part and an outer part of the top portion are constructed so as to be detachable each from the other. The inner part extends substantially adjacent the screw nipple and at least a portion of the inner part is provided with an insulating coating of high temperature stability, which represents a loosely surmounted moulding.

Abstract: Electrode for fused melt electrolysis comprising a top portion (5) of metal or metal alloy where appropriate including a cooling device (2,3) and the top portion (5) is protected at least partially by an insulating coating (4) of high-temperature resistance, and at least one bottom portion (6) of active material. The electrodes can be used more particularly for the electrolytic production of metals such as aluminium, magnesium, alkaline metals or compounds thereof and are characterized by very advantageous energy consumption combined with high operational reliability.

Abstract: Electrode for fused melt electrolysis with a top portion (5) of metal, where appropriate with a cooling device (2, 3) and the top portion (5) has an inner part (16) and an outer part (17) which are constructed so as to be detachable from each other and the inner part (16) extends substantially close to a connection or screwmounting (1) and the top portion (5) or the inner part (16) or at least a partial zone thereof is protected by an insulating coating (4) of high temperature stability, and at least one bottom portion (6) of active material. The electrode is suitable for the production of metals such as aluminium, magnesium, alkali metals or compounds thereof. It is characterized by reliable, energy saving operation and can be easily maintained and repaired.

Abstract: An electrode holder for arc furnace electrodes having a cooled metal shaft at least partially surrounded by a protective jacket of hollow cylinder configuration, generally moldings resistant to elevated temperatures. The protective jacket can surround and protect portions of the electrode holder positioned within the furnace or portions of the electrode holder in a zone engaged by clamping jaws. The protective jacket consists of individual moldings configured to provide generally ring shapes which may be put together to form rings, and coherently surrounding the metal shaft.

Abstract: In this system, the electrode supporting arms (2) formed of a closed, hollow, liquid cooled profile for an electric furnace are provided with a vertical member (14) having the same type profile structure at whose lower end the electrode (17) is exchangeably fastened, preferably by means of a clamping device (15). For better current transfer, the supporting arms (2) are in part made of a two-component compound material, preferably to correspond to their current charges.

Abstract: A composite electrode for an electric arc smelting furnace has a metal liquid cooled upper clamped section, a consumable graphite lower section and a metal liquid cooled connecting pin. The upper section is fitted with loosely fitting arcuate graphite segments (46) over the area of the electrode held in the electrode power clamp during furnace operation.

Abstract: Electrode for fused melt electrolysis with a top portion (5) of metal, where appropriate with a cooling device (2, 3) and the top portion (5) has an inner part (16) and an outer part (17) which are constructed so as to be detachable from each other and the inner part (16) extends substantially close to a connection or screw-mounting (1) and the top portion (5) or the inner part (16) or at least a partial zone thereof is protected by an insulating coating (4) of high temperature stability, and at least one bottom portion (6) of active material. The electrode is suitable for the production of metals such as aluminium, magnesium, alkali metals or compounds thereof. It is characterized by reliable, energy saving operation and can be easily maintained and repaired.