Abstract: Provided are a heat treatment apparatus for carbonaceous grains and a method therefor allowing drifts and internal clogging in a direct energizing furnace to not occur, allowing heat treatment of the carbonaceous grains to be continued uniformly at high temperatures for a prolonged period of time, and allowing productivity and workability to be improved. A conductive tubular structure 14 is electrically connected to an upper part of a lower electrode 13 in a manner of surrounding an upper electrode 12. The rate of change between the specific electrical resistivity of grains when grains are lightly filled and the specific electrical resistivity of grains when the grains are tap filled is defined (1-tap filling/lightly filling)×100, and the rate of change is equal to less than 70%.

Abstract: A graphite electrode exhibits oxidation resistance by modifying the outer radial surface characteristics. The outer radial surface may be modified by providing a textured portion which improves water flow while minimizing water absorbtion. Alternately, a layer of flexible graphite or plurality of particles of exfoliated graphite may be disposed on the outer radial surface of the electrode body.

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: Some embodiments relate to an electrical contact assembly for a plasma torch tip, and may include an electrical contact portion, a compressible portion in mechanical communication with the contact, and a mounting portion in mechanical communication with the compressible portion. Some embodiments may be adapted to maintain contact with an uneven substrate during translation of the torch tip.

Abstract: [Object]: The present invention provides a process and a device for producing a quartz glass crucible, which generates a stable ring-like arc and is suitable for the production of an excellent crucible having the large open diameter.

Abstract: An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil.

Abstract: An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil.

Abstract: A method for feeding fines or granules into a light-arc furnace. A hollow electrode provided with a feeding channel is utilized, and is preferably a hollow Söderberg electrode. A conveyor introduces the fines or granules into the feeding channel so as to maintain in the feeding channel a hollow material in which a lower end is smelted in a molten metal bath.

Abstract: An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil.

Abstract: A smelting furnace system for smelting metals, especially steel scrap, with a lower furnace vessel, in the bottom of which a tap hole is provided, and with an upper furnace vessel, which can be closed by a cover, in which a central pipe is provided coaxially with respect to the main axis of the furnace, in which pipe at least one electrode is arranged, and on which pipe there is provided a component which encompasses the upper furnace vessel and can be connected to a gas offtake device. In this arrangement, a slit is provided in the wall of the central pipe in a longitudinal direction. A sleeve is fastened at the edge of the slit, allowing the central pipe to be fastened to the casing of the upper furnace vessel having a corresponding slit. Furthermore, a supporting arm, which is connected to a supporting pillar arranged outside the furnace, can be led through the hollow space of the sleeve into the central pipe, with at least one electrode fastened on the front face of this arm.

Abstract: An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil.

Abstract: An oxygen injector for a post combustion system used in an electric arc furnace includes a housing formed of a concave configured front wall and a spaced rear wall. The housing has a width greater than the spacing defined between the front wall and spaced rear wall. An oval configured conduit wall is located medially in the housing and extends from the rear to front wall to form an oval configured oxygen chamber and a water chamber with the oxygen chamber bound internally by the conduit wall. Orifices are formed in the front wall within the oxygen chamber.

Abstract: In an arc furnace or melter furnace employing concentric graphite inner and outer electrodes, the accumulations of tolerances, distortion and mechanical forces can cause a loss of concentricity leading to reduced performance and eventually to electrode degradation. To avoid that condition, a plurality of insulating spherical or cylindrical spacers are disposed in the annular gap between the inner and outer electrodes. The spacers are held in position by arcuate recesses in the outer surface of the inner electrode or in the inner surface of the outer electrode. The electrodes may be constructed in segments that are assembled by threading one segment into another segment.

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: In a method for processing solid residues from refuse incineration plants the slag is melted and heavy metals from the melt (16) are separated for reutilization. The slag is directly transferred from the refuse incineration plant into a first heating chamber (2) and melted there under oxidizing conditions. The melt (16) produced therefrom is transferred to a second heating chamber (3), in which the heavy metal compounds are reduced to their metallic form. Furthermore, additional finely divided residues, such as fly ash, boiler ash and filter dust, are introduced into the second heating chamber (3) via a hollow graphite electrode (19). The melt (16) is then passed on to a third heating chamber (4), in which the residual readily volatile metals are vaporized and the residual non-volatile metals are sedimented. The essentially heavy-metal-free melt is then cooled to form vitreous granules.

Abstract: In order to avoid damage to the inner walls of the arc furnace (1) and a reduction of the electric power when material (5) to be melted has been partly burned down in an arc furnace (1), additives (10) are fed to the filling opening of a hollow electrode (7) by means of a loose-material conveyor (25) during this critical melting phase. An arc (6) between the hollow electrode (7) and a melt (4) in the arc furnace (1) is thereby shortened. A loose-material container (9) is arranged at the end of the loose-material conveyor (25) at a distance from the electrode and can easily be separated from the hollow electrode (7) in order to permit the tilting of the arc furnace (1) to empty out the melt (4). Problematic waste materials which are to be disposed of, such as for example filter dust, can be added to the additives (10).

Abstract: A method and a d.c. arc furnace for thermal treatment of an ash, wherein reducing conditions are established within a closed and sealed furnace, the ash is supplied via a channel arranged in an electrode which extends towards a metal melt in a furnace shell and provides an arc extending toward the metal melt, the ash being fed from the open free end of the electrode through the arc, any slag and/or the metal melt, whereby the ash is rapidly heated under reducing conditions to a temperature of 1350.degree. C. to 1750.degree. C.

Abstract: A method and apparatus for processing a contaminated free-flowing material and, in particular, filter dust from industrial metallurgical waste and domestic waste incineration plants are disclosed.

Abstract: The invention relates to a procedure for continuous supply of heat into electrically conductive bulk goods by exploiting the electrical resistance thereof in an oven chamber with an inlet opening and a drawing-off apparatus for continuous throughput of bulk goods, wherein during the throughput of material, electrical energy in the material is conducted, and to an apparatus for continuous supply of heat into electrically conductive bulk goods by exploitation of the electrical resistance thereof, in an oven chamber (1) with an inlet opening (15) and a continuous drawing-off apparatus (9) for the bulk goods, and with at least one pair of electrodes (14, 16, 19) arranged one above the other, via which the electrical energy in the material is conducted during the continuous throughput of material.

Abstract: An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil.

Abstract: A process and low-shaft furnace for disposing of filter material. The material to be disposed of is charged via a charging device onto and/or into a slag bath in the furnace. Simultaneously, additives comprising fluxing agents, slag-making constituents and reducing agents are introduced into the slag via a separate immersion lance. Finally, during the introduction of the additives the variables forming the electrical resistance, essentially the electrodiameter, center distance between the electrodes, level of the slag bath, and the immersion depth of the electrodes in the bath are adjusted so that 70% of the electrical energy is introduced between the electrodes and 30% of the electrical energy is introduced between the electrodes and the metal bath on the hearth bottom.

Abstract: A process and device for melting scrap in a direct current-driven closed shaft furnace. The scrap is fed with an annular cross-section into one end of the furnace and hot gases which flow against the falling scrap are sucked below the scrap feeding area via an outer cylindrical wall of the scrap column. The inner free surface of the ring-shaped flat cross-section of the scrap is reduced before the scrap reaches the melting zone. In the melting zone, the scrap is exposed to an electric arc at the center of the flat cross-section. The arc furnace has a cathode that is held by an electrode bearing device which is formed as a concentric pipe with respect to the central axis of the furnace vessel. At one end the pipe is conically tapered and at the other end it is supported on the shaft of the furnace by bearing arms.

Abstract: An object of the invention is to provide an ingot having improvement of and a prevention of occurrence of segregation when electroslag remelting method is used for producing a large size ingot and a super alloy which is sensitive to segregation. According to the present invention, the electrode for electroslag remelting method has a hole formed along an axial direction in the core of an electrode. Therefore, the molten pool is made shallow so that flat and segregation is prevented from occurring. Consequently, an ESR ingot of good quality is accomplished with an excellent surface and is free from segregation. Moreover, an electrode melting rate is increasing and efficiency is improved.

Abstract: There is disclosed an electric arc furnace for the production of steel by melting scrap, in particular iron scrap, and/or sponge iron and/or pig iron as well as fluxes in a furnace vessel, into which at least one graphite electrode projects, which is displaceable in its longitudinal direction, wherein an electric arc is ignited between the graphite electrode and the charging stock. To achieve a particularly high energy input, the graphite electrode projects into a lower part of the furnace vessel from aside and the lower part, in the region of the graphite electrode, has an enlargement radially protruding outwardly relative to the upper part.

Abstract: The invention relates to an electrode system for melting and stirring and also for temperature control in metallurgical vessels. To achieve optimum energy utilization with minimal gas consumption, the electrode system comprises, according to the invention, a central electrode and an outer electrode (10, 11) which are each attached to a height adjustment (12) and are connected to a common electric power source (16), to form an electric arc between central electrode and melt below the surface of the melt bath, and an annular space (23) between central electrode and outer electrode (10, 11), which is connected to a gas source (25), with the gas system being designed in such a way that finely particulate additives can also be charged into the melt.

Abstract: An object of the present invention is to provide an ingot wherein occurrence is prevented when an electroslag remelting method is used for producing a large ingot and which a super alloy is sensitive to segragation. According to the present invention, the electrode for electroslag remelting method has a hole formed along an axial direction in the core of an electrode. Therefore, the molten pool is made shallow so that flat and segregation is prevented from occurring. Consequently, an ESR ingot of good quality is accomplished with an excellent surface and is free from segregation. Moreover, an electrode melting rate is increasing and efficiency is improved.

Abstract: In a method of producing metal melts, in particular a steel melt from scrap, in an electric arc furnace having at least one graphite electrode, organic substances are charged into the electric arc through a central longitudinal recess of the graphite electrode so as to reduce electrode consumption.

Abstract: Threaded nipple for joining two electrode sections is provided with an integral ridge intermediate its threads for centering the electrodes in coaxial alignment.

Abstract: The present invention is directed to process and apparatus for mixing finely divided calcium carbide and finely divided lime and carbonaceous material and for feeding the mixture down through the aperture of a hollow electrode in a calcium carbide electric furnace. In a preferred embodiment the finely divided calcium carbide is supplied to the aperture of the hollow electrode by a first conveyor and a fine feed mix of lime and carbonaceous material is supplied to the aperture of the hollow electrode by a second separate conveyor and the two are mixed in fluidized condition and fed down through the aperture of the electrode into the reaction zone of the furnace. Carbon monoxide off-gas from the furnace is preferably used for fluidizing the respective particles.

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: The present invention is directed to process and apparatus for mixing finely divided calcium carbide and finely divided lime and carbonaceous material and for feeding the mixture down through the aperture of a hollow electrode in a calcium carbide electric furnace. In a preferred embodiment the finely divided calcium carbide is supplied to the aperture of the hollow electrode by a first conveyor and a fine feed mix of lime and carbonaceous material is supplied to the aperture of the hollow electrode by a second separate conveyor and the two are mixed in fluidized condition and fed down through the aperture of the electrode into the reaction zone of the furnace. Carbon monoxide off-gas from the furnace is preferably used for fluidizing the respective particles.

Abstract: A melt reduction furnace has a flat gas-tight roof through which the oxide feeding electrode projects an extent less than usual inside the furnace to reduce its breakage risk, and a side wall gas exhaust opening above an upstanding threshold providing low-velocity gas exhaust while the threshold holds back gas flow with possible dust below the opening.

Abstract: Thread material is removed from the non-load bearing flank of a selected number of threads on each side of the center thread of a nipple to provide increased strength for an electrode joint formed therewith.