Abstract: Provided are a furnace shell with a lower electrode at a bottom of the shell, a furnace roof adapted to close an upper portion of the furnace shell, a material charge port substantially at a center of the furnace roof and two upper electrodes positioned laterally opposite to each other with respect to the material charge port and vertically extending through the furnace roof. Scrap material is continuously charged through the material charge port and arcs are directed to the scrap material at a center of the furnace shell.

Abstract: A furnace preheat system uses furnace off-gas to preheat material to be charged into the furnace. In a preferred embodiment of the invention, first and second angularly-spaced preheat vessels are mounted on a rotatable member which rotates them to a position over the furnace for charging the furnace and to a position for preheating the material in the preheat vessels. There is ductwork from the furnace to the first and second preheat vessels to selectively vent the off-gases to the first and second preheat vessels.

Abstract: A method and apparatus for reducing the production or emission of noxious gases while continuously preheating a mixture of iron-bearing scrap charge materials for an electric steelmaking furnace operation with off-gas from, the furnace, including provision for controlled combustion within the preheating chamber. Removed gases are then treated by thermal incineration of combustible residual matter before release into the atmosphere to insure that no noxious gases are emitted.

Abstract: A smoke suction duct of an electric furnace is constructed as a separate member from other exhaust duct portions and other devices and is supported to be rotatable about an axis of the duct. Further, the smoke suction duct is either alternately turned to right and left or continuously turned in one direction by a duct turning device. Since accumulating dust is raised to an upper portion of the smoke suction duct where an exhaust gas flow has a high velocity due to rotation of the smoke suction duct and is pushed toward a combustion tower by the exhaust gas flow, dust is advantageously prevented from accumulating on a bottom of the smoke suction duct.

Abstract: Installation for producing steel by melting scrap comprising an electric furnace (2') supplied with individual batches of scrap sequentially charged into the furnace after preheating in a preheating chamber (4) forming a batch container open at both ends and having a releasable bottom. The preheating chamber is mounted on a transporting device for movement between a first, preheating position, in which it is connected to a hot gas circulating circuit, and a second position in which it empties the batch of preheated scrap into the furnace. The lower portion of the side wall of the preheating chamber (4) forms a skirt (43) with a wide downwardly directed opening, and the chamber (4) is combined, in the preheating position, with a movable device (54) for sealably engaging the lower end (42) of the skirt (43) with a matching stationary base plate (3), whereby the skirt is sealed in the preheating position.

Abstract: A furnace comprises a space overlying a charge into which space opens at least one oxygenated gas injector passing through the periphery of the furnace to deliver within this space a jet of gas that is nonradial relative to a vertical axis of the space. Each injector comprises a) a head (14) disposed within the thickness of the wall (1) of the furnace and having a gas passage having an axis (11) inclined at a predetermined angle (.alpha.) to an axis (15) that is substantially radial relative to the vertical axis of the space overlying the charge and b) a substantially cylindrical body (16) prolonging the head and the gas passage within the furnace along this substantially radial axis (15), itself substantially perpendicular to the wall (1) through which it passes. The injector is useful in an electric furnace for melting scrap for the production of steel.

Abstract: Interferant eliminating analyte sensors and sensing process prevent erroneous assays. Glucose electrodes were coated with an oxidizing enzyme (peroxidase) which allows hydrogen peroxide to selectively oxidize ascorbate, urate, bilirubin, and acetaminophenol in the presence of glucose. Hydrogen peroxide may be added to the assayed solution or generated in situ. The oxidizing enzyme was prevented from causing undesired reduction currents at the glucose electrode by preventing contact of the oxidizing enzyme with the glucose electrode, or by increasing the applied voltage.

Abstract: For obtaining mineral fibers from a thermoplastic material having a high melting point, and more precisely for the regulation of the flow rate and temperature of the stream of molten material distributed on the fiber-drawing machine, the molten material is conveyed via a reservoir where the flow rate is regulated and the height of the molten material at the base of the tapping aperture is controlled by inclining the reservoir. Preferably the molten material is subject to a basic heating process which raises its temperature close to the fiber-drawing temperature and, in the vicinity of the tapping aperture, it is subject to additional heating in order to adjust the temperature precisely.

Abstract: In a smelting plant including two melting furnaces which are arranged in juxtaposed relationship and which are operated alternately, wherein the furnace gases which are produced in the melting process are respectively introduced into the other melting furnace for the purposes of preheating the charging material, associated with each melting furnace is a shaft which is loaded with charging material, and the waste gases from the furnace which is in the melting mode of operation are introduced from the shaft, after charging of the other furnace, through the cover of the other furnace, and are removed from the shaft thereof. That procedure, throughout the entire smelting operation, permits preheating of charging material and filtration of the furnace gases when they are passed through the charging material.

Abstract: A biosensor including an interferant-eliminating catalyst and method for analyzing an analyte in a biological sample is disclosed.

Abstract: A method of preparing a melt for mineral fibre production wherein a mixture of mineral fibre-forming raw materials is introduced into a shaft furnace and is heated to melting temperature by a plasma gas stream formed in a plasma torch and wherein waste material from mineral fibre production is introduced into the plasma gas stream by a rotatable screw conveyor mounted in a feed pipe, the melt formed in the shaft furnace is being discharged from the bottom of the furnace and passed to a fiberizing apparatus in which it is converted into mineral fibres.

Abstract: This invention is directed to a smelting plant with shaft-like charging material preheater. In a smelting plant with an electric arc furnace (1) and a charging material preheater (2) of shaft configuration arranged laterally on the furnace, the outer walls of the charging material preheater in the lower region thereof are formed by the vessel wall (5) of the furnace while in the region thereabove they are formed by the walls of a shaft which is fixed in a holding structure (27). By a horizontal relative movement between the furnace vessel (3) and the holding structure (27) together with the vessel cover (6), without being impeded by the shaft (10) charging material can be charged from a scrap basket directly into the furnace vessel or through the displaced shaft into different regions of the furnace vessel (3). Charging material can be retained in the shaft by means of a blocking member (51) therein, and heated up during the refining phase.

Abstract: In a smelting unit comprising an arc furnace and at least one shaft-like charging material preheater which is arranged laterally on the furnace vessel of the arc furnace and the interior of which is connected in a region adjoining its bottom to the interior of the furnace vessel by way of a connecting zone, and in addition burners open in the lower region of the charging material preheater, in a sump mode of operation after the tapping step, of the amount of charging material which is required for the next bath of molten material, a part thereof is charged directly into the furnace vessel in order to reduce the smelting time. That part of the charging material is preheated in a preheating chamber which is connected downstream of the charging material preheater.

Abstract: A plant for the processing of exhaust gases of an electric melting furnace for steel is disclosed, which allows to improve the cleaning of heavy-metal-containing exhaust gases from electric arc furnaces for steel production from scrap, which allows to decrease the energy use for capturing waste from the exhaust gases, which avoids the odor molestation by the waste gases generated in connection with an electric melt furnace operation during the preheating and for making useful the exhaust gases for the smelting under incorporation of the drying of oil-containing roll sinter muds, where simultaneously the oil-content of these roll sinter muds is used for saving of electric arc melting energy.

Abstract: An apparatus and method for charging a melting furnace having a charging opening in its sidewall, in which a closed housing contains a vibrating pan having an intergal discharge chute adapted to extend into the charging opening in the furnace sidewall; and a truck-mounted carriage for moving the charging apparatus into the charging opening of the furnace and removing the apparatus to a position remote therefrom. A method for feeding the furnace over a predefined area, and continuously feeding the furnace during all phrases of operation, including slagging and tapping, is also disclosed.

Abstract: In a method for melting a material selected from the group consisting of scrap or other similar materials with at least one melting furnace in a crucible equipped with electric arc heating, comprising directly pre-heating the material with the exhaust gases of the melting furnace and charging the material from the pre-heating vessel into a melting vessel prior to charging the heated scrap, each melting vessel is positioned below a stationary pre-heating vessel; and after charging the heated scrap, each melting vessel is positioned back above a stationary melting surface.

Abstract: An apparatus and method for charging a melting furnace having a charging opening in its sidewall, in which a closed housing contains a pivotally mounted receiving pan having a discharge chute on one side thereof, the discharge chute adapted to extend into the charging opening in the furnace sidewall; and means for moving the charging apparatus into the charging opening of the furnace and removing the apparatus to a position remote therefrom. A method for feeding the furnace over a predefined area, and continuously feeding the furnace during all phases of operation, including slagging and tapping, is also disclosed.

Abstract: A heat recovery and storage system for use in connection with a melting furnace. In such system, heat from the exhaust gas of a melting furnace is recovered and used to preheat scrap metal and to maintain such preheated scrap metal in its preheated form until it is charged into the melting furnace.

Abstract: A multi-purpose pyrometallurgical process enhancing device for metallurgical furnaces can be employed in oxy-fuel burner mode for preheating and melting of solid charge, in an oxygen injecting lance mode for decarburization of molten metal in metallurgical furnaces, in particular in melting electric arc furnaces, plasma arc furnaces and basic oxygen furnaces, and in an injector mode for injecting solid materials; the device includes a pivotally mounted water cooled generally arcuate body which can be pivoted into and out of a furnace vessel through a small opening in the shell wall for optimal positioning of the oxy-fuel flame against solid charge, in the burner mode; or injection of oxygen vertically downwardly into the molten metal at supersonic speed, in the oxygen lance mode; in one embodiment the arcuate body can be rotated about its longitudinal axis for directing the oxy-fuel flame towards a cold spot in the furnace; the tip of the arcuate body includes a replaceable, multi-opening nozzle, mounted in a

Abstract: A preheating mechanism for use with a duplex electric-arc furnace system is disclosed. The mechanism comprises a car travelling in a direction parallel to the straight line connecting the centers of the two furnaces, and a traversing car that is positioned above said first car and travels in a direction transversal to the direction in which said first car travels, said traversing car being capable of travelling over said first car in said transversal direction until it reaches a position where it overhangs either one of the two furnaces, said traversing car being provided with a raw material preheating combustor and a dust collecting hood in such a manner that each of said combustor and hood can be raised or lowered in the vertical direction.

Abstract: An arc furnace having a space for accommodating charging material, said space being disposed on one side of the furnace vessel and communicating with the interior of the furnace vessel and being disposed at least partly in the region of radiation of the arc of at least one arc electrode. The arc electrode is movable towards and away from the charging material accommodating space, and thereby permits better utilization of the radiant heat generated by the arc.

Abstract: A method of preheating scrap metal with impure gases discharging from a metallurgical vessel includes the steps of conducting a first portion of the gases to a container of scrap metal, contacting the scrap metal with the gases for preheating the same whereby additional impurities are generated, withdrawing the impure gases after contact with the scrap metal and mixing the same with a second portion of impure gases from the metallurgical vessel, thermally cracking the mixture in a combustion chamber to remove impurities and thereafter removing particular matter from the gases prior to the discharge to the atmosphere.

Abstract: A process for preheating scrap that is to be charged into a smelting furnace using, in part, heat provided by the smelting furnace discharge fumes. The scrap is preheated with clean gas heated by a heat exchanger that exchanges heat between furnace discharge fumes and clean gas. A plant for the preheating process includes a device to gather and convey hot fumes leaving the furnace connected to both the furnace and a heat exchanger, a device to convey cooled fumes from the heat exchanger, a device to convey clean gas connected to the heat exchanger inlet, and a device to convey preheated clean gas from the heat exchanger to at least on skip of scrap.

Abstract: An arc furnace installation wherein the arc furnace is air-tightly enclosed with a shroud and a scrap preheating chamber moves into or out of the shroud in such a way that the preheating chamber may be selectively brought to a position immediately above the arc furnace, a scrap preheating position spaced apart from the arc furnace by a predetermined distance and a scrap charging position outside of the shroud. The number of openings of the shroud may be reduced to a minimum and consequently the total area of the openings may be minimized.

Abstract: A method and apparatus for preheating scrap metal within pure gases discharged from a metallurgical vessel. The method comprises the steps of burning the gases in a combustion chamber to remove impurities therefrom, conducting a first portion of the combustion products to a container of scrap metal, contacting the scrap metal with the combustion products for preheating the scrap metal whereby additional impurities are generated, washing in a wet scrubber the mixture of combustion products and additional impurities, mixing the scrubbed combustion products and additional impurities with a second portion of the combustion products from the combustion chamber, and removing particulates from the mixture.

Abstract: This disclosure relates to a system for preheating scrap before charging in an electric furnace and for preventing the release of malodorous or noxious gas. The system includes a first duct leading from the furnace exhaust gas outlet to a chimney; a branching duct is connected in the first line for passing part of the gas to the chimney and for diverting the remainder of the gas to a scrap preheater. After preheating the scrap, the diverted gas is recirculated back to the first line at a junction which is adjacent the furnace outlet. The system further includes gas combustion means connected in the first line between the junction and the branching duct, and a heat equalizer-accumulator in the first line between the combustion means and the chimney. The system may further include a heat exchanger connected in the first line downstream of the branching duct and a second line for passing the diverted gas through the heat exchanger after it leaves the scrap preheater.

Abstract: Apparatus for preheating scrap material, e.g. scrap metal, comprises heaters, such as air preheaters, scrap containers and air or gas conduits for conveying heated gas from the heaters to the scrap container(s) and back from the scrap container(s). The apparatus is characterized in that the conduit to the scrap container(s) is provided with valve means for diverting the flow of hot air or gas to the container(s), for example during replacement of container(s).

Abstract: A reverberatory furnace for melting aluminum or other metals which includes a preheater (12) which utilizes exhaust flue gasses from the furnace (10) to preheat the metal before it enters the furnace. A set of horizontal flue ducts (18, 20, 22) conduct the flue gasses to a preheater chamber (26) where they heat the metal. An air entrance port (50) is provided in the preheater chamber (26) to allow secondary combustion of the volatile flue gasses for additional efficiency.

Abstract: A primary duct is provided for supplying hot waste gas from an electric furnace to a preheater bucket charged with scrap. A preheating waste gas duct connected to the bucket is branched into a discharge duct for releasing preheating waste gas from the apparatus and a recycling duct for recycling preheating waste gas to the primary duct. In the vicinity of the junction of the primary duct and the recycling duct, an air inlet is formed for supplying air into the primary duct for burning the preheating waste gas.

Abstract: At least one arc furnace and at least one induction furnace are connected to the same AC network, the induction furnace being connected via a controllable alternating voltage converter so as to permit compensation of active power fluctuations in the network caused by operation of the arc furnace and the induction furnace being designed to contain scrap for its inductive preheating before charging in the arc furnace.

Abstract: A preheating apparatus for preheating the material, such as scrap, to be charged into steel making equipment with the heat of exhaust gas from the equipment. The apparatus comprises a plurality of preheating units for dischargeably accommodating the charge. The preheating units are connected together in series by ducts to pass the exhaust gas through the units in series and preheat the charge in the units.

Abstract: A method for preheating steel scrap by an exhaust gas from a steelmaking electric furnace, which comprises: directing, when manufacturing steel from steel scrap in an electric furnace, an exhaust gas produced in said electric furnace to an exhaust gas combustion chamber provided in the middle of a discharge duct of said exhaust gas to cause combustion of carbon monoxide contained in said exhaust gas to form a combustion exhaust gas; and selectively directing part of said combustion exhaust gas into at least one scrap preheating chamber provided in the middle of a branch duct branching off from said discharge duct to preheat steel scrap charged in said scrap preheating chamber to a prescribed temperature; said method being characterized by: feeding back all of said combustion exhaust gas after preheating said steel scrap charged in said scrap preheating chamber to said exhaust gas combustion chamber to cause combustion of an incomplete-combustion gas which is produced by the incomplete combustion of combustibl

Abstract: A metal melting furnace is provided having an enclosing roof that has a refractory brim portion affixed to and carried by the side walls, and has a refractory crown portion that is adapted to be removably positioned to close-off and open a central charging opening defined and encompassed by the brim portion. The crown portion by-passes electrodes in its "down" position and is to be raised and lowered and swung into and out of a clearing position with respect to the charging opening. Exhaust fume from a side-positioned smoke hole of the furnace is directed either into and positively drawn through a side-positioned-preheating scrap container or through an exhaust chest for subsequent environmental treatment before discharge into the atmosphere.

Abstract: An apparatus for the manufacture of steel by direct reduction of iron ore dust comprises a single reactor vessel and a tubular reduction dust extending into the vessel to a point closely adjacent to the bottom of the vessel. The reactor vessel is provided with a source of reducing gas containing a monoxide and a predominant amount of H.sub.2. Heating mechanisms for the reduction dust, the iron ore dust, the source of reducing gas and the vessel are provided. The apparatus also includes a mechanism for the recycling of heat and the components of the waste gases of the reactor vessel.