Abstract: An arc furnace bottom construction for maintaining the outer surface temperature of the bottom construction essentially at least on the lower part of the arc furnace essentially close to the temperature surrounding the arc furnace. The bottom construction contains at least two constructions to be cooled and being positioned to each other in different heights seen from the side view.

Abstract: A method and apparatus for melting aluminum uses a dense metal salt of Rubidium, Cesium, or Strontium. The salt is melted by a stinger and then superheated by AC applied to electrodes immersed in the salt. Aluminum in contact with the salt melts and floats on the salt. In continuous scrap melting, inflows and outflows of aluminum are comparable and may be shielded by inert gas. The superheated salt may be purified and may be heated in a separate reservoir and pumped to and from another reservoir containing salt and/or metal. The salt may be used to supplement the heating of an existing furnace.

Abstract: An apparatus for casting metals by a nucleated casting technique to create a preform, the apparatus including a mold having a base and a side wall where the base can be moved relative to the side wall to withdraw the preform as it is being created. In various circumstances, portions of a droplet spray created by an atomizing nozzle, i.e., overspray, may accumulate on a top surface of the side wall and prevent or inhibit the preform from being moved relative to the side wall. The atomizing nozzle can be oriented such that the droplet spray passes over the top of the side wall to remelt and remove at least a portion of the overspray that has accumulated thereon. The mold can be rotated such that the overspray formed on a region of or on the entire perimeter of the top surface can pass through the droplet spray and can be removed from the side wall.

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 movable device for injecting oxygen and other technical materials into an electric arc furnace includes a housing situated above a portion of a step of a crucible and equipped with a cooling coil, an injection lance of oxygen and other technical materials, a supporting and moving system of the lance between minimum and maximum range points of the liquid bath level contained therein, positioned in the housing, an opening situated in the housing and facing the inside of the crucible in which the lance is transferably guided, and a scraping member disposed between the opening and the lance.

Abstract: A sensor system for monitoring and controlling the performance of the bottom electrode and the deflection of an electric arc in an electric steel making furnace includes an organized matrix of anode pins interspersed with refractory material and extending toward an electrically conductive plate secured to distal ends of the anode pins. A sensing device includes two temperature sensors at spaced apart locations along each of a distributed select group of anode pins for providing corresponding electrical signals and a current sensor responsive to electrical current flowing through the anode pins of the distributed select group of anode pins for providing a corresponding electrical signal. A controller responsive to the electrical signals derived at the anode pins of the select group operates the power supply and a display for monitoring the electrical performance of the elongated anode pins for heating by the electric arc in the furnace.

Abstract: A brick hearth system includes a rigid containment shell in which a concave bottom is lined with a hearth refractory sub-layer and hearth brick working layer. The outer perimeter of the hearth refractory is ringed with thrust blocks to compress the whole toward the center and to thereby deny gaps from forming between the separate bricks. Many individual thrust rods penetrate the outer bottom of the containment shell, and such are used to transmit compression forces generated outside the shell to be applied against the thrust blocks in unison. Each thrust rod receives an adjustable amount of inward force from a spring, acting either directly or through a beam or rocker arm. These are anchored to and use the hoop strength of the containment shell as leverage. As the hearth brick working layer grows during its service life, the ring of thrust blocks grows in diameter as well inside the margins provided within the containment shell.

Abstract: A sill and door jamb assembly providing an opening in an electric arc furnace, the sill and door jamb assembly having a sill block assembly and two jamb block assemblies. The sill block assembly having side-by-side sill blocks, each of the sill blocks being positioned side-by-side to form the sill block assembly and having an upper end and a lower end. The lower end of the sill block assembly is confined within a plurality of courses of the refractory bricks. Each jamb block assembly having a plurality of jamb blocks positioned side-by-side. Each of the jamb block assemblies having a lower end and an inner surface abutting the distal ends of the sill block assembly. The inner surfaces of the jamb block assemblies and the upper surface of the sill block assembly form the slag opening in the furnace.

Abstract: In a method of charging fine-grained metals, in particular directly reduced iron (DRI), into an electric-arc furnace (1), the metal is supplied via a downpipe (12) to an opening (10) provided in the furnace roof (4), is introduced into the furnace (1) through this opening (10) as bulk material stream (11), and falls onto the melt (13) merely by gravity. Further, an electric-arc furnace (1) suited for this purpose is described. A rather loss-free introduction even of fine-grained material having a mean grain size of less than 1 mm is achieved by passing the bulk material stream (11) through a dosing orifice (8) after the downpipe (12) and before entering the furnace (1). The bulk material stream (11) then enters the furnace essentially undisturbed.

Abstract: A brick hearth system comprises a rigid containment shell in which a concave bottom is lined with a hearth refractory sub-layer and hearth brick working layer. The outer perimeter of the hearth refractory is ringed with thrust blocks to compress the whole toward the center and to thereby deny gaps from forming between the separate bricks. Many individual thrust rods penetrate the outer bottom of the containment shell, and such are used to transmit compression forces generated outside the shell to be applied against the thrust blocks in unison. Each thrust rod receives an adjustable amount of inward force from a spring, acting either directly or through a beam or rocker arm. These are anchored to and use the hoop strength of the containment shell as leverage. As the hearth brick working layer grows during its service life, the ring of thrust blocks grows in diameter as well inside the margins provided within the containment shell.

Abstract: A burner and/or injector panel apparatus includes a flange rotatable within a cylindrical aperture in a horizontal plate and securely retainable between one or more retaining clips and the plate. Extending downward from the flange is a main body with a cylindrical chamber. A burner, burner/injector, or injector is contained within the cylindrical chamber. The main body has a helical cooling circuit extending around the cylindrical chamber and burner and/or injector. The burner and/or injector panel apparatus may be installed through a furnace wall, especially an electric arc furnace, more particularly, a balcony panel of a sump area of an electric arc furnace. The burner and/or injector panel apparatus may be tilted from horizontal or rotated around its vertical axis in order to better target a target area of a molten bath of metal with a flame, jet of oxygen, or stream of carbon particles.

Abstract: Method for heating a fluid, in particular a fluid which is not electrical conductive, where a rotor body (10) which is arranged in a chamber for absorption of the fluid, is rotated with a generally vertical shaft (11). A voltage is applied to a rod shaped electrode (16) which is arranged centrally in a rotor chamber (12) and to an electrode at the bottom (13) of the rotor chamber, for creation of a flame arc, so that a flow of the fluid passing the flame arc is created. The length (L) of the flame arc is held generally stable, preferably constant by controlling the position of the rod shaped electrode (16). The fluid is made enter the rotor chamber (12) so that it is kept outside the flame arc, and that the fluid is provided to flow through the rotor chamber (12).

Abstract: An enclosure for mounting burners and particle injection equipment in an electric arc furnace (EAF) is described. The enclosures are mounted on the sidewalls of an EAF and include passages in which burners or injectors are mounted so that the discharge ends of the burners and injectors are located closer the melt than sidewall mounted burners and injectors. Burners and injectors mounted in the enclosures heat material in the furnace and deliver particulates to the melt more efficiently than conventionally mounted burners and injectors. The enclosures are liquid-cooled, typically by water, and constructed of high conductivity materials such as copper and/or cast iron and can be constructed in one or more pieces. Therefore, the enclosures protect the burners and injectors from the excessive heat and mechanical impact to which they would normally be subjected when mounted so close to the melt.

Abstract: An inner lining for the steel shell of a carbothermic reduction furnace for the production of alumina has a base layer of graphite and a coating layer of refractory material. The refractory material is corundum (Al2O3) bound by Sialon (Si.Al.O.N). The lining structure provides protection against the molten slag and it is not attacked by the CO-rich melt furnace atmosphere. Further, the lining does not contaminate the melt and it provides an effective heat dissipation system in case of a power shut-off.

Abstract: A hearth plate (30) includes a flat rectangular plate (32) having a top surface (34), a bottom surface (36), and a plurality of through openings (38) between the top surface (34) and bottom surface (36), four support walls (40) having top edges connected around the periphery of the bottom surface (36) and bottom edges and a bottom wall (42) connected to the bottom edges of the support walls (40). A preheater structure (46) is mounted in the space (44) defined by the four support walls (40), flat rectangular plate (32) and bottom wall (42), and a rectangular enclosure comprising four interconnected graphite walls (54, 56, 58) is mounted around the peripheral edge of the top surface (34) to define a processing volume for receiving objects (50) to be processed. A graphite lid (72) is removably supported by the rectangular enclosure.

Abstract: Process and equipment for the treatment of loads or residues of non-ferrous metals and their alloys including the steps of loading of scraps or dross to be processed; heating the load (29) and melting the metal; revolving the heated load (29), tapping the molten metal and emptying the cavity (28) of the furnace, being the heating up of the load (29) or residues (23) to a temperature above the melting temperature of the metal or non-ferrous alloy to be recovered carried out by means of a free burning convective arc which is independent from the supply of external gas to the process, and which may dispense with the use of melting salts.

Abstract: An electric arc furnace (10) has an outer shell (12) and an inner refractory lining (24). During its operation the electric arc furnace (10) contains a bath (28) of molten metal which has a minimum and a maximum operational level (32). An inner cooling ring (23) of copper slabs (20), which are in thermo-conductive contact with the inner refractory lining (24) and equipped with spray cooling means (22), is mounted to the outer shell (12) in the region (34) between the minimum and the maximum operational level (32).

Abstract: A method for refining and casting metals and metal alloys includes melting and refining a metallic material and then casting the refined molten material by a nucleated casting technique. The refined molten material is provided to the atomizing nozzle of the nucleated casting apparatus through a transfer apparatus adapted to maintain the purity of the molten refined material. An apparatus including a melting and refining apparatus, a transfer apparatus, and a nucleated casting apparatus, in serial fluid communication, also is disclosed.

Abstract: A metal mounting assembly for mounting a burner or lance in a furnace has a water-cooled main body securable in an aperture in a furnace wall, a series of cooling fins extending from the main body so as to project into the furnace when secured thereto, and at least one mounting tube extending through the main body for mounting a burner or lance therein.

Abstract: The aim of the invention is to improve the cooling of the bottom electrodes (1) of metallurgical melting vessels. To this end, a cooling plate (5) is situated beneath the support plate (2) on which the contact elements (3) are supported. The cooling plate is set apart from the support plate. This forms a cooling chamber (4) through which a cooling medium flows, the cooling effect of said medium being reinforced by cooling ribs (6). Said cooling ribs are situated in the cooling chamber (4) and are welded to the support plate (2) and preferably, also to the cooling plate (5).

Abstract: A bottom electrode of a direct current electric arc furnace includes an electrode body extending through a hole defined in a bottom of the furnace. A circumferential flange is formed around a lower portion of the electrode body to which a ring connection member is attached. The connection member forms a ring channel defined by inner and outer walls from which inner and outer flanges radially extend in opposite directions. The inner flange is fixed to the circumferential flange of the electrode body by bolts. The outer flange is fixed to the furnace bottom for attaching the bottom electrode to the furnace bottom. The channel is located between the circumferential flange of the electrode body and an inside diameter of the hole defined in the furnace bottom for increasing radial distance between the electrode body and the hole of the furnace bottom. Insulative members are arranged on and under the circumferential flange of the electrode body for electrically isolating the electrode from the furnace bottom.

Abstract: A mounting enclosure and an improved mounting arrangement for apparatus used in metal melting, refining and processing, particularly those apparatus adapted for steel making in an electric arc furnace, such as burners, lances and the like with supersonic oxygen lancing capability and injectors or the like for the introduction of particulate matter. The mounting enclosure is fluid cooled to survive the hostile environment of the electric arc furnace and is designed to occupy the step between the side wall and hearth of the furnace without any substantial change to the structure of the furnace. The mounting enclosure comprises a plurality of fluid cooling conduits surrounding an apparatus aperture and an injector aperture which are formed through the enclosure and adapted to mount an apparatus and an injector. The mounting arrangement includes utilizing the mounting enclosure to mount an apparatus with supersonic oxidizing gas lancing capability and an injector for particulate carbon in an electric arc furnace.

Abstract: A base of a metallurgical vessel having a direct-current arc device whose cathode projects into the vessel and in whose fire-resistant lining on the base at least one anode is arranged, one end of which, passing through the vessel wall, touches metallic melt located in the vessel, and the other end of which can be connected to cooling fluid supply sources and is attached in an electrically insulated manner to the vessel wall via holding elements. A sleeve is provided which does not conduct electric current, sheaths that part of the anode which projects into the metallurgical vessel and, in the process of forming an outlet channel, is arranged at a distance sufficiently far away from the anode that low-melting-point metals, mainly lead, can flow out of the vessel without being impeded.

Abstract: An electric furnace includes a stationary lower shell having a sloping floor extending downwardly to a tap hole to always maintain a sufficient ferrostatic head three times the tap hole for slag free tapping. The configuration of the refractory for containing a heat, is sufficient to maintain a liquid metal heel of at least 70% of the heat before tapping for maintaining flat bath operation during refining a steel melt. An upper furnace shell is supported on the lower furnace shell and a furnace roof is supported by the upper furnace shell. The entire furnace is mounted on a furnace transfer car that is anchored for stationary operation but moved to a furnace exchange position for servicing any of the components making up the furnace. The furnace roof and/or upper furnace shell may be supported at a furnace operate position while the lower furnace shell is transported to the furnace exchange position.

Abstract: Discharge screw (6) for a moving hearth, and in particular for an annular rotary hearth (2) of a reheat furnace for the heat treatment of loose materials, comprising a cylinder (61) arranged above and substantially radially with respect to this annular hearth (2) and turned by suitable actuators (15) so as to discharge the materials from the edges of this annular hearth (2); this cylinder (61) comprises on its lateral surface a first series of helicoids (62) beginning in an area close to its outermost end with respect to the furnace and a second series of helicoids (63) beginning at its innermost end with respect to the furnace; the inclination of the helicoids (62) of this first series is essentially symmetrical to the inclination of the helicoids (63) of this second series; and in this screw (6) each helicoid (62, 63) of one series comprises an inward end that meets the inward end of a corresponding helicoid (63, 62) of the other series in such a way that at at least one of the abovementioned ends a free fi

Abstract: Method and device to feed tuyeres in an electric furnace, the tuyeres comprising a central conduit to deliver a comburent gaseous substance and a peripheral conduit to deliver a cooling gaseous substance, the method providing to send to the central conduit a comburent mixture consisting of oxygen and neutral gas (N2, Ar, etc.) in defined percentages, the oxygen and the neutral gas being fed, for each of the tuyeres, to a mixing device with a high mixing capacity, at least the pressure of the neutral gas being able to be adjusted on the relative feed line so as to modulate the pressure of the mixture according to the characteristics of the melting process.

Abstract: Discharge screw (6) for a moving hearth, and in particular for an annular rotary hearth (2) of a reheat furnace for the heat treatment of loose materials, comprising a cylinder (61) arranged above and substantially radially with respect to this annular hearth (2) and turned by suitable actuators (15) so as to discharge the materials from the edges of this annular hearth (2); this cylinder (61) comprises on its lateral surface a first series of helicoids (62) beginning in an area close to its outermost end with respect to the furnace and a second series of helicoids (63) beginning at its innermost end with respect to the furnace; the inclination of the helicoids (62) of this first series is essentially symmetrical to the inclination of the helicoids (63) of this second series; and in this screw (6) each helicoid (62, 63) of one series comprises an inward end that meets the inward end of a corresponding helicoid (63, 62) of the other series in such a way that at at least one of the abovementioned ends a free fi

Abstract: A mounting enclosure and an improved mounting arrangement for apparatus used in metal melting, refining and processing, particularly those apparatus adapted for steel making in an electric arc furnace, such as burners, lances and the like with supersonic oxygen lancing capability and injectors or the like for the introduction of particulate matter. The mounting enclosure is fluid cooled to survive the hostile environment of the electric arc furnace and is designed to occupy the step between the side wall and hearth of the furnace without any substantial change to the structure of the furnace. The mounting enclosure comprises a plurality of fluid cooling conduits surrounding an apparatus aperture and an injector aperture which are formed through the enclosure and adapted to mount an apparatus and an injector. The mounting arrangement includes utilizing the mounting enclosure to mount an apparatus with supersonic oxidizing gas lancing capability and an injector for particulate carbon in an electric arc furnace.

Abstract: A method and an apparatus for advantageously introducing a flame and a high velocity oxidizing gas into a furnace for metal melting, refining and processing, particularly steel making in an electric arc furnace. The steel making process of an electric arc furnace is made more efficient by shortening the time of the scrap melting phase and introducing an effective high velocity oxidizing gas stream into the process sooner to decarburize the melted metal. In one implementation of an apparatus, improved efficiency is obtained by mounting a fixed burner/lance closer to the hot face of the furnace refractory at an effective injection angle. This mounting technique shortens the distance that the flame of the burner has to melt through the scrap to clear a path to the molten metal and shortens the distance the high velocity oxygen from the lance travels to the slag-metal interface thereby increasing its penetrating power.

Abstract: A VAR process is conducted in an apparatus characterized by a crucible wall that provides a stable shelf anchor. The VAR apparatus includes a furnace chamber, a consumable electrode formed of a material to be remelted within the furnace chamber and a crucible within the furnace chamber. The crucible has a wall that forms a vessel to collect melt material from the consumable electrode. At least part of the wall is textured to provide area for mechanical stabilization of the shelf as the underside of the shelf melts and the upperside of the shelf forms. In a vacuum arc remelting process, a consumable electrode is loaded into a furnace chamber above a cooled crucible having a textured wall that forms a vessel to collect melt material from the consumable electrode. The process includes striking a direct electric current between the electrode and a bottom of the crucible to cause melting of material from a tip of the electrode. Melt material is collected from the tip in the crucible.

Abstract: A mounting block and an improved mounting arrangement for apparatus used in metal melting, refining and processing, particularly those apparatus adapted to steel making in an electric arc furnace, such as burners, lances and the like with supersonic oxygen lancing capability. The mounting block is fluid cooled to survive the hostile environment of the electric arc furnace and is designed to rest on the step between the side wall and hearth of the furnace without any substantial change to the structure of the furnace. The mounting block comprises a plurality of fluid cooling conduits surrounding an aperture which is formed through the block and adapted to mount the apparatus. The mounting arrangement includes utilizing the mounting block to mount an apparatus with supersonic oxidizing gas or lancing capability in an electric arc furnace. The apparatus is mounted by passing it through an aperture in a water cooled side panel aligned with the mounting aperture in the mounting block.

Abstract: Device to cool and protect a cathode in an electric arc furnace, wherein the cathode comprises at least a consumable column, a structure, hollow on the inside and containing a cooling liquid, arranged around the column and provided with a first lower chamber in which a liquid is suitable to evaporate and a second upper chamber in which the condensation of steam is suitable to occur, at least two vertical conduits being provided to connect the two chambers.

Abstract: An improved apparatus for EAF steelmaking providing a lance for the injection of oxidizing gas, preferably oxygen, or other metallurgical gases and particulate materials into a steelmaking process. In one embodiment, the apparatus comprises a lance body configuration which has a central conduit for the supply of a pressurized flow of oxygen. A consumable lance tip made of refractory material is connected to the lance body such that it is in fluid communication with the central conduit.

Abstract: Spray cooled side wall and tap hole cover for an eccentric bottom tap (EBT) electric furnace which is unitary, i.e. one-piece, and has an inter-connected coolant supply and inter-connected spent coolant drain.

Abstract: Basket to manipulate scrap in cooperation with an arc furnace (11) and with means to pre-heat the scrap by means of the fumes from the fourth hole (14), the basket being able to be associated with a movable covering system (16) and including a containing body, a bottom equipped with toothed lower closing means which may be momentarily opened, and lateral extensions for moving and positioning the basket, the containing body comprising a first upper part (10a) which acts as a buffer store to temporally increase the capacity of the basket (10) and a second lower part (10b) to contain the scrap, with a capacity substantially mating with the volume of the load of the melting furnace (110) which it has to feed, wherein the second lower part (10b) is associated with cooling means.

Abstract: A direct current electric arc furnace for melting or heating raw material or molten material includes a refractory lined vessel for holding raw or molten material in its interior. The furnace includes at least a first top electrode. The first top electrode enters the vessel interior above the raw or molten material. The furnace includes at least a first bottom electrode mounted in the bottom of the vessel and in electrical contact with the raw or molten material in the vessel. The furnace includes an electrical power supply mechanism which electrically connects to the top electrode and the bottom electrode in order to input electrical energy into the material through the top and bottom electrodes in the form of an arc. The bottom electrode has opposite electrical polarity to the electrical polarity of the top electrode. The furnace also includes a mechanism for cooling the first bottom electrode with a spray of water and air that contacts the first bottom electrode.

Abstract: Provided is a process for melting a charge in a furnace. Energy of fusion is supplied to the charge, and gases including at least one combustible gas are generated during the the melting. A post-combustion of the combustible gas is performed by injecting an oxidant gas containing more than 25% by volume of oxygen during at least some periods of the process. The oxidant gas is injected above the charge, in the form of at least one oxidant gas jet. Each jet has a flow rate of between approximately 50 and 1200 Sm.sup.3 /h and a speed of injection into the furnace of between approximately 5 m/s and 150 m/s. The process has particular applicability to an electrical furnace for melting scrap for the production of steel.

Abstract: The present invention relates to an electrode for a metallurgical vessel and to a cooling element for a wall of a metallurgical vessel. In particular, the present invention provides an electrode and a cooling element having a cavity, a device for cooling by spraying a cooling medium into the cavity, and a collecting device for collecting molten metal that breaks through the cavity. The present invention also relates to a DC arc furnace comprising at least one electrode of the present invention.

Abstract: This invention is directed to a method and apparatus for thermal homogenization of molten metal in a heath of a electric arc furnace for steel production. The invention addresses the problem of lack of thermal homogenization by providing a lance which directs oxygen gas downwardly towards the surface of the bath and into the molten metal in a direction that diverges away from a direct line to a central region of the hearth through a horizontal divergence angle in the range of 10.degree. to 50.degree. thereby to enhance movement of the molten metal about the hearth and the direction of the gas is inclined downwardly to strike the nominal horizontal plane of the surface of the bath at an inclined angle in the range of 35.degree. to 50.degree. thereby to minimize splashing of the molten metal.

Abstract: A crucible (10) for the inductive melting or superheating of metals, alloys, or other electrically conductive materials is provided with palisades of approximately equal length, arranged vertically, parallel to, and a certain distance away from, each other around a circle so as to surround the melt. A plate-shaped or ring-shaped part (4) at the bottom ends of the palisades (3, 3', . . . ) holds the palisades (3, 3', . . . ). At least part of the palisades (3, 3', . . . ) are provided with cavities (5, 5', . . . ) or channels, through which a coolant flows. An induction coil (6), through which an alternating current flows surrounds the palisades (3, 3', . . . ) spaced from their outside surfaces. The palisades (3, 3', . . . ) have slots (7a, 7b, 7c;, 7a', 7b', 7c', . . . ), which extend vertically from the palisade-holding part (4) up to a point near the top edge. The inside wall (9, 9', 9", . . .

Abstract: A method and apparatus for producing crude liquid steel using direct reduced iron as a raw material in an electric arc furnace with an acid resistant sidewall refractory lining. In order to effect the more economical melting operation, the electric arc furnace uses a slag containing a B4 ratio of (lime+magnesia)/(silica+alumina) in the range of about or less than 1.50, resulting in less slag volume, reduced electric power consumption, reduced electrode consumption, and improved iron yield.

Abstract: An electric arc furnace includes a closed melting vessel and includes an opening that can be closed where metal to be molten is charged into the melting vessel. At least one electrode extends into the melting vessel and generates an electric arc and forms a molten metal bath. At least one oxygen lance can be extended into the melting vessel for injecting oxygen into the molten metal bath and create a reaction where the carbon monoxide is generated. Gas is exhausted from the melting vessel and the carbon monoxide gas concentration of the exhaust gas is measured. A post combustion chamber receives the exhaust gas and provides post combustion of the exhaust gas. Post combustion oxygen is injected into the melting vessel in an amount sufficient to provide post combustion based on the amount of oxygen necessary for post combustion of the exhaust gas and the post combustion chamber.

Abstract: Cooling system for electrodes (11) in D.C. electric arc furnaces, the electrodes (11) comprising a part (11a) subjected to the hot environment of the furnace, this part being made of graphite in the case of a cathode and of copper in the case of an anode, the part (11a) being associated with a metallic part (11b) by means of a joint (13) which includes inside itself a hollow (14), comprising at least in correspondence with the metallic part (11b) a cooling circuit (20) with at least a delivery channel (15), a return channel (16) and a heat exchanger (18), the circuit (20) using liquid metal as a cooling fluid, there also being included means for the forced circulation of the cooling fluid consisting of a hydromagnetic pump (17).

Abstract: An improved return path for electric current through a conductive hearth of a direct current arc furnace is provided by pressing a ring of water cooled copper blocks into the periphery of a sidewall of the hearth of the furnace, the hearth having zones of conductive refractory providing an electrical path between the contents of the furnace of the copper blocks. The hearth is compressed by a tensioned peripheral band which may also support the blocks. The peripheral water cooled copper blocks may be divided into multiple groups, each group connected to one pole of a direct current power supply, the opposite pole of which is connected to a suspended electrode, permitting control of arc deflection.

Abstract: Device to support and swing the hearth in an electric furnace, whether it be the type operating on direct or alternate current, the furnace being able to be of the channel type, EBT with the hearth lowered or not, OBT or other type, the hearth (11) cooperating at the upper part with a cooled side wall (12) having a closure system (14) which can be temporally associated, the hearth (11) being supported by a platform (18), the device comprising a plurality of lifting cylinders (19, 119) associated at the lower part with the platform (18) and at least a translation and/or oscillation actuator (20, 120; 32) associated at the side of the platform (18), the lifting (19, 119) and translation (20, 120; 32) cylinders being able to be driven independently and in a correlated manner so as to obtain on the hearth (11) desired movements of lifting, translation, swinging, oscillation or a combination of such movements.

Abstract: A bottom electrode for a metallurgical vessel operated with direct current, consisting of an outer part made of a first material arrangeable substantially outside a bottom of the vessel so as to face the vessel, and an inner part made of a second material and connected to the outer part so as to face an interior of the vessel. The inner part is configured to wear when in contact with molten metal in the vessel, and includes a metallic first structural part that consists substantially of a material comparable to the molten metal. The first structural part has an end adjacent the outer part with a cross-section adapted to that of the outer part. The first structural part is configured to prevent a flow of melted electrode material as well as the molten metal. The inner part further includes a high temperature resistant second structural part configured to compliment the first structural part, the first and second structural parts being coaxial to one another.

Abstract: A charge of scrap is melted in a furnace (1) with post-combustion of the fumes by injection of an oxygenated gas into the space in the furnace above the charge. During periods of post-combustion, the oxygenated gas is injected in the form of several jets each having a flow rate comprised between about 400 and 1200 Nm.sup.3 /h and an injector (11, 12) outlet speed comprised between about 50 and 150 m/s, preferably between about 500 and 900 Nm.sup.3 /h and between about 70 and 125 m/s. Several groups of injectors (11, 12) are used, having an outlet tangential component relative to the vertical axis (X--X) of the furnace (1), successive groups of injectors being disposed at different levels (N.sub.1, N.sub.2) and oriented in alternate circumferential directions.

Abstract: A metallurgical vessel heated by direct current, particularly for the production of ferroalloys, including a metallic jacket lined with refractory material and a bottom electrode. A bottom electrode (22) is located within the interior of the vessel and arranged below a refractory side wall (12) of the metallurgical vessel (10). Bottom electrode (22) is constructed from electrically conducting refractory material. The periphery of the electrically conducting bottom (22) is surrounded by metallic plates (25), each of which is connected to current rods (31) which extend through a metallic jacket (11) and out from the vessel. Plates (25) and current rods (31) are separated from the metallic jacket (11) by electrical insulation (32). The electrode device in the bottom of the vessel ensures electrical contact over as large an area as possible.

Abstract: Melting method for an electric arc furnace with alternative sources of energy for the melting of iron-based alloys, the electric furnace (10) including tuyeres (13) positioned on the bottom to deliver oxygen, at least one tuyere (15) to deliver coal dust which works in the area of contact between the bath of molten metal (16) and the layer of slag (22), at least one supersonic lance (12) cooperating with a lance (29) to deliver coal dust, these lances (12, 29) having a working position (12c, 29c) in which the supersonic lance (12) is positioned in close proximity to the surface of the molten metal (16) and the lance (29) to deliver coal dust is positioned in the vicinity of the surface of the layer of slag (22), and a plurality of burners (28) positioned on the cooled sidewalls (31) of the furnace (10) and delivering oxygen-based gases and combustible substances, whereby at least two first burners (28) work with the action of one burner supporting the action of the next one, the furnace (10) being charged wit

Abstract: A melting vessel plant, in which the melting vessel is a converter vessel, to which a vessel cover with a pipe connection for removing the flue gases is attached. Either an oxygen lance with an auxiliary cover or electrodes with an auxiliary cover are introduced into the melting vessel through the vessel cover. The spherical melting vessel is lined with a lining. It is arranged on running rails as a traveling melting vessel, and it is mounted on an inner running rim and an outer running rim. The melting vessel is fastened to the inner running rim by support elements arranged on the circumference. Both running rims are interlocked by shear wedges. With the melting vessel locked, a cable winch with traction cables makes possible the tilting movements of the melting vessel both in the direction of steel tapping on the running rails and back into the upright position.