Abstract: A vessel for containing direct reduced iron (DRI), such as a reactor for the production of DRI, a bin or a hopper or other container for storing or feeding DRI to melting furnaces or briquetting machines, includes at least an upper zone, defined by a first lateral wall having a substantially cylindrical tubular shape, and a discharge zone, positioned below the upper zone and defined by a second lateral wall having a substantially truncated cone shape converging toward a lower discharge aperture. The second lateral wall has an internal surface at least partly lined by an internal lining.

Abstract: A glass melting plant having a melting tank having end-fired heating, the melting tank having a feeding material inlet, an outlet for removing the molten glass, and a melt surface of at least 40 m2. At least one doghouse is laterally situated and is connected to the melting tank inlet for feeding material input. The doghouse has side walls that, together with the melting tank inlet, limit a feeding surface area, and has a feeding device. The doghouse has a roof with an end wall oriented toward the feeding device, which end wall encloses, with the roof, a gas compartment open toward the melting tank. To increase the specific melting performance with at least equal glass quality, the feeding surface of the doghouse is at least 8 m2 and, given a melt surface of at least 115 m2, is at least 7% of the melting tank melt surface.

Abstract: Processes of controlling submerged combustion melters, and systems for carrying out the methods. One process includes feeding vitrifiable material into a melter vessel, the melter vessel including a fluid-cooled refractory panel in its floor, ceiling, and/or sidewall, and heating the vitrifiable material with a burner directing combustion products into the melting zone under a level of the molten material in the zone. Burners impart turbulence to the molten material in the melting zone. The fluid-cooled refractory panel is cooled, forming a modified panel having a frozen or highly viscous material layer on a surface of the panel facing the molten material, and a sensor senses temperature of the modified panel using a protected thermocouple positioned in the modified panel shielded from direct contact with turbulent molten material. Processes include controlling the melter using the temperature of the modified panel. Other processes and systems are presented.

Abstract: A glass melting tank comprising at least one front part for introducing the charge material, and at least one charging device. To reduce atmospheric heat losses and reduce dust transport into the upper furnace of the tank, and nevertheless to intensify the heating of the charge material, the front part has a length “LV” of at least 2,250 mm in the direction of the melting tank, and a length “LG” of at least 1,200 mm is provided with an insulating roof. An end wall near the charging device, together with the roof, encloses a gas chamber open toward the melting tank. A characteristic value “K” of 3.50 tonnes (t) per hour and per square meter of surface is not exceeded. The characteristic value is calculated from P/F, where P is the throughput per hour in tonnes (t) and F is the inner surface of the front part in m.

Abstract: Delivery apparatus include an electrical circuit configured to heat a linear conduit and an elbow conduit. A first electrode can be mounted to an upstream portion of the linear conduit, a second electrode can be mounted downstream of the upstream portion, and a third electrode can be mounted to a curved segment of the elbow conduit within a footprint extension of a first passage of the linear conduit. In further examples, a delivery apparatus includes an electrical circuit with a first electrode mounted to an upstream portion of a linear conduit, a second electrode mounted to a downstream portion of the linear conduit, and a third electrode mounted to an elbow conduit. In still further examples, methods of heating molten glass include application of an electrical current such that neither a current flux through a linear conduit nor a current flux through an elbow conduit exceeds 8 amps/mm2.

Abstract: A process for the manufacture of mineral wool can involve, first, a melting stage which makes it possible to obtain a molten glass. The chemical composition of the molten glass comprises the following constituents, in a content by weight, within the following limits: SiO2, 39-55%; Al2O3, 16-27%; CaO, 3-35%; MgO, 0-5%; Na2O+K2O, 9-17%; Fe2O3, 0-15%; and B2O3, 0-8%. The melting stage is carried out by electric melting in a furnace that has a tank made of refractory blocks and at least two electrodes immersed in the molten glass. At least one of the refractory blocks, in contact with the molten glass, is made of a material having at least 60% by weight of zirconium oxide and less than 5% by weight of chromium oxide. The molten glass is fiberized to obtain the mineral wool.

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 sensor apparatus for an electrochemical measuring device. The apparatus has at least one electrode, which can be heated using a heating current in the form of an alternating current, and a first and a second connection for the supply line for the heating current. The electrochemical measuring device is connected to the electrode by a third connection. In this case, the apparatus has the third connection connected to the electrode by a bridge circuit, which is also connected to the first and second connections. There also is provided a method for carrying out electrochemical measurements at elevated temperature. The sensor apparatus and the method for carrying out electrochemical measurements enable electrochemical measurements with little interference and directly heated electrodes in conjunction with a simplified design of the electrodes.

Abstract: The invention relates to a device for the production of a glass melt from a batch; with a melt tank (1) that has peripheral walls (1.1-1.4) and a bottom (1.5); with a discharge channel (2) which is located under the bottom (1.5) of the melt tank (1) and which is in conducting connection with the melt bath (3) over an entry opening (2.3) and has an outlet opening (2.4) for the finished melt in the zone of a peripheral wall (1.1) of the melt tank (1); with at least one heating arrangement for the heating of the melt bath (3); the entry opening (2.3) of the discharge channel (2) is arranged in a central zone of the bottom (1.5) of the melt tank (1); the discharge channel (2) has a covering (2.2) which is located at least approximately at the level of the bottom (1.5) of the melt tank (1).

Abstract: The invention relates to a device for the production of a glass melt from a mixture; with a melt tank (1) that has peripheral walls (1.1-1.4) and a bottom (1.5); with a discharge channel (2) which is located under the bottom (1.5) of the melt tank (1) and which is in conducting connection with the melt bath (3) over an entry opening (2.3) and has an outlet opening (2.4) for the finished melt in the zone of a peripheral wall (1.1) of the melt tank (1); with at least one heating arrangement for the heating of the melt bath (3); the entry opening (2.3) of the discharge channel (2) is arranged in a central zone of the bottom (1.5) of the melt tank (1); the discharge channel (2) has a covering (2.2) which is located at least approximately at the level of the bottom (1.5) of the melt tank (1).

Abstract: Provided herewith is a method for preheating a glass mixture to be fed into a glass furnace. The method comprises separately preheating at least some of the materials which comprise the load, and then subsequently remixing the preheated materials and passing the load to the glass furnace.

Abstract: A raw-material heating apparatus in which raw-material supplying pipes and exhaust pipes are disposed in a peripheral portion of a furnace cover, a heating space is formed by the furnace cover, a peripheral wall, and a hearth, a raw material which is supplied from the raw-material supplying pipes and deposited on the hearth is heated by a heating gas which flows into the heating space, and pushers are supported by the peripheral wall for pushing out the raw material on the hearth toward a drop port formed in a central portion of the hearth, the deposited raw material on the hearth being caused to drop consecutively through the drop port by the reciprocating motion of the pushers, characterized in that lower-end openings of each raw-material supplying pipe and each exhaust pipe, when viewed in an axial direction of the apparatus, are disposed at a same position or at positions close to each other in an effective region for pushing out the raw material by the pusher.

Abstract: The invention relates to the electric melting technique, in which the melting energy is dissipated in the bath of melted glass as a result of the Joule effect by means of electrodes which dip through the surface of the bath. According to the invention, the electrodes dip into a bath of melted glass which has a height h below 800 mm and a surface S such that the ratio h/S is lower than 0.5 m/m.sup.2. According to another aspect, the exchange surface between the electrodes and the bath is above 0.075 m.sup.2 /m.sup.3 of glass.The invention is used in the manufacture of glass-based products, such as insulating materials based on glass fiber.

Abstract: The bottoms of exhaust stacks and systems on glass melting furnaces usually collect slag that is produced by volatiles in the exhaust gases condensing out and forming a glassy substance on the cooler walls of the stacks, etc. which then runs down the walls picking up refractory and forming a slag in the lowest places. This slag often cools to hardness or a high viscosity, tough mass. It has to be removed periodically to prevent building up to the point that slag would run back into the furnace damaging the glass and removal is a hot, dirty, time consuming job. This problem is worse on oxy-fuel furnaces which the industry is trending towards for other advantages. The present invention eliminates this problem by reducing the size of the reservoir in the bottom of the stack and adding a heated bushing with an orifice that continually drains the slag from the small reservoir.

Abstract: Apparatus and method for melting glass in a glass melter in such a way as to reduce deposition of particulates in the off-gas duct. Deposit accumulation is reduced by achieving an off-gas velocity above approximately 15 meters/second and an off-gas temperature as close as possible to, but not higher than, the glass softening point. Because the deposits are largely water-soluble, those that do form on the interior surface of the duct can be readily removed by injecting water or steam directly into the off-gas duct from its entrance or exit.

Abstract: The invention relates to a process for the continuous treatment of silicon in which a slag in a pivotable low-shaft furnace (1) with a discharge pipe (4) reaching the bottom of the furnace tank is taken to a temperature of 1450.degree. to 1800.degree. C. and this slag is used to melt solid silicon and/or liquid silicon is continuously refined and the liquid refined silicon is then sprayed with compressed air or nitrogen (7) and continuously conveyed into a transport crucible (11) by being poured into a stream of water (9) in the channel (8) via a dewatering filter (10) and thus obtained in granular form. The invention also relates to devices for implementing the process.

Abstract: The furnace for melting materials with a low melting point with improved casting duct comprises a furnace body which surrounds a crucible for containing the molten material and which is provided with first resistors for heating the crucible, the casting duct having an inlet arranged above the level of the free surface of the molten material in the crucible and being fed by a ladle for removing molten material, the casting duct being further provided with second resistors for heating thereof in order to prevent accidental cooling of the molten material along the duct.

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: A fired, porous, zircon refractory body consisting essentially of zircon and having a sodium ion content, as an impurity, of less than 30 ppm. A furnace for making fused silica constructed with a crown and cup of such zircon refractory, and a method of making fused silica using such furnace.

Abstract: A batch charger for a molten glass furnace comprising a stationary hopper having an inlet opening at the upper end and an outlet opening at the lower end. A reciprocable charger plate located below the outlet opening of the hopper to supply material from the hopper to the furnace. The charger plate has a bottom wall and upstanding sidewalls at the edges of the bottom wall which are outwardly spaced from the sidewalls of the hopper. An adjustable seal is attached to the rear wall of the hopper with a lower edge located below the lower edge of the rear wall of the hopper and depending flapper members are pivotally attached to the front wall of the hopper at each edge to prevent loose material from passing between the sidewalls of the charger plate and the sidewalls of the hopper when the charger plate is reciprocated.

Abstract: A method of feeding glass to a glass-melting furnace for making a vitreous material, a heated airstream containing air at a temperature in excess of 1,000.degree. C. is passed down vertical cylinders towards the crown of the glass-melting furnace. Powdered glass batch is introduced into the vertically moving heated airstream in the lower and wider cylinder and infra-sound is applied to the vertically moving heated airstream by an infra-sound generator to vibrate the heated airstream and effect heat transfer from the airstream to the glass batch particles so that the glass batch particles are heated and the temperature of the heated airstream is reduced to a temperature below 700.degree. C., thereby reducing the propensity of the air to produce nitrogen oxides.

Abstract: A method and apparatus for feeding iron-bearing particles into a metallurgical furnace such as an electric arc furnace, comprising a vessel for containing a bath of molten iron, having a wall extending above the bath of molten iron, a preferably screw type feeder mounted on the exterior of the vessel, a feeding port in the vessel wall shaped to permit passage of the feeder into the interior of the bath of vessel and located at such a height from the molten iron so that no molten materials will spill out from the furnace through the port during the normal operation and maneuvering of the furnace; and actuating means for extending the screw type feeder from a retracted position out of the vessel to an extended position into the vessel.

Abstract: A batch charger for feeding raw batch material to a glass making furnace of the type having a reciprocating charger plate positioned under a hopper chute. A pusher bar is supported substantially parallel to the front edge of the charger plate, and rams are connected to the pusher bar to move it from a position under the charger plate such that raw batch that has been delivered over the edge of the charger plate can be pushed further into the furnace.

Abstract: A melting apparatus in which a material to be melted is accommodated in a crucible made of platinum or its alloy, and electric current passes through the crucible to generate heat ot melt the material. At least a part of the crucible is formed into a double-wall structure having inner and outer peripheral walls. The electric current is caused to pass through the double-wall structure to generate the heat.

Abstract: A bottom outlet device is provided for a glass melting furnace, with heating of a glass melt being effected to within the temperature range of the electrical conductivity of the melt by way of electrodes disposed in the interior of the furnace and projecting into the melt. An inductively heatable and metallic outlet unit projects from the bottom of the furnace and includes an outlet opening and an interior outlet channel communicating with the outlet opening. An outlet block comprised of ceramic bricks is disposed above the outlet unit and includes a throughgoing channel which opens toward the interior of the furnace and which is flush with the interior outlet channel of the outlet unit. A bottom electrode comprised of metal is disposed at a lowermost portion of the interior of the furnace. The bottom electrode is penetrated by a further channel which is flush with the throughgoing channel in the outlet block and is thereby in communication with the outlet opening of the outlet unit.

Abstract: An electric melting furnace for solidifying highly radioactive waste in glass has a melting cavity made of a non-conductive refractory and adapted to melt a raw material consisting of highly radioactive waste and a glass material by passing a current between horizontally opposing electrodes, and to extract the molten glass material through a plurality of outlet ports at a bottom portion of the furnace, the melting cavity being partitioned by a non-conductive partitioning refractory provided on the bottom portion of the furnace between outflow ports. Since the furnace is so structured that the melting cavity is partitioned by the non-electrically conductive refractory, all current lines connecting the pair of electrodes for melting the highly radioactive waste, which contains elements of the platinum group, detour around the partitioning refractory.

Abstract: A method for thermal decomposition treatment of a radioactive waste uses an apparatus comprising a container for holding molten matter of a radioactive waste containing a sodium compound, a pair of electrodes contacting the molten matter, and a power source for applying voltage between the electrodes while changing the polarity thereof every several tens of seconds. In this apparatus, the molten matter can be heated in the container by Joule heat, which is evolved by electric current directly flowed through the molten matter, so that the sodium compound contained in the radioactive waste can be decomposed, vaporized and removed to recover a stabilized radioactive solid as a residue in the container.

Abstract: A process intended to prevent the formation of metal deposits on the walls (1) of metallurgical containers in contact with the molten metal bath (12). An improved container for carrying out this process is also described. Formation of deposit can be prevented by applying an electric voltage between the molten bath (12) and the wall (1).

Abstract: Glass is made from a feed consisting of batch materials and cullet in a furnace that is both electrically and gas fired. A batch-only hopper discharges through a blanket conveyor to a batch melting chamber that is electrically fired and is connected via a submerged throat to a fritting chamber where the at least partly molten batch materials are mixed with cullet fed from cullet-only hoppers by blanket feeders. The fritting chamber is fired by a combination of electricity and roof-mounted flat flame burners. Material passes from the fritting chamber to a secondary reheating and refining chamber which is heated by regenerative gas burners. The separation of batch materials from cullet and separate melting thereof in a pre-melter means that the feed to the secondary refining and conditioning chamber is relatively free of fines and requirement to melt only cullet in the fritting chamber and secondary refining chamber enables those chambers to be operated at a lower temperature than the batch melting chamber.

Abstract: An electric melting furnace for glassifying high-radioactive waste characterized in that, in a furnace for melting glass containing platinum-group elements which has an outlet of glass at the bottom part of a melting tank, the bottom of the furnace surrounding the outlet has an inclination of more than 30.degree. and not more than 70.degree. with respect to the horizontal plane toward the cullet, and the distance l.sub.1 between a surface-inside opening part of the outlet and bottom ends of at least a pair of electrodes (3a, 3b) for supplying most of power required for glass melting is a half or more, but not exceeding, of the distance (l.sub.2) between the electrodes (3a, 3b).

Abstract: The joule melter has an outer cylindrical electrode which forms the outer wall of the melt containment, an inner cylindrical electrode which protrudes upward in the containment and forms the outlet for the melt, thus, also determining the depth of the melt. A non-conducting sealing material forms a base plug between the electrodes. A cylindrical electrically conductive baffle is located between the electrodes and includes an opening which allows the melt to flow from near the outer electrode where the melt material is first inserted into the melter, to the inner electrode which is the outlet. In addition to the inner and outer electrodes, the baffle may be connected to a power supply to modify the currents flowing at each of the electrodes.

Abstract: Molten slag is fed from a receptacle to an atmosphere-controlled carbon-lined electric furnace through a refractory-lined siphon tube without allowing atmospheric gases to enter the furnace. Siphoning is initiated by reducing the atmospheric pressure within the furnace through the use of an auxiliary vacuum tank. Slag from the furnace is spun to form mineral wool insulation.

Abstract: A substantially spherically-shaped electric melting furnace includes a carbon-lined crucible. The interior of said crucible is sealed from the atmosphere outside the crucible and a vacuum pump and venturi device control the atmosphere within the crucible by removing oxygen therefrom. A feeder lock allows material to be fed into the crucible without interfering with the atmospheric control of the crucible and a tap hole adjacent the lower portion of the crucible allows molten material to be removed. When used in the manufacture of mineral wool insulation, slag is fed into the crucible to be melted and the molten slag from the tap hole is delivered to a fiberizing device.

Abstract: An electric furnace for fusing of fusible metal/non-metal oxide compounds, for example slag, having a side wall of steel, a plurality of electrodes depending into the furnace, a coolant distributing conduit surrounding the furnace near its upper end, and a tapping valve located in the side wall of the furnace between its upper and lower ends, the furnace being operated by melting the slag to form a melt, the outer layer of which is in contact with the inner surface of the furnace side wall which is frozen by the chilled coolant flowing over the outer surface thereof, to thereby form a frozen slag lining on the side wall inner surface which is continuously replenished as it is depleted.

Abstract: A method and a system for uniformly heating a glass stream flowing in the feeder of a glass melting furnace wherein power or energy is supplied through the electrodes immersed in the glass melt and wherein the temperature of the glass stream is continuously detected, has the current flowing between cooperating electrodes maintained constant independently of the resistance defined by the glass melt by controlling the voltage as long as the temperature of the glass stream does not deviate from predetermined limits and the current flow of at least a number of electrodes positioned at the inlet of the feeder are controlled to compensate for temperature variations when the tolerable deviation limit has been exceeded.