For Manipulation Of The Charge Or Melt (e.g., Stirring) Patents (Class 373/85)
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Patent number: 10731923Abstract: A furnace includes a tank having outer and inner walls defining a closed canal to be filled with molten metal continuously circulating along the canal. The canal includes at least one heating area having a heating component for transferring energy to the molten metal thus overheating it; at least one loading area for loading metal or metallic waste into the molten metal; a melting/treatment area for receiving the overheated molten metal and material dragged on its surface. The overheated molten metal transfers its exceeding energy to the material, causing its melting/treatment. The furnace has a central hollow delimited by the inner wall and a driving component within the hollow, having a rotor with at least one magnet body and coupled to a motor and configured to rotate upon activation of the motor, generating a magnetic field capable of causing circulation of the molten metal in a continuous and cyclical manner.Type: GrantFiled: April 7, 2016Date of Patent: August 4, 2020Assignee: DIGIMET 2013 SLInventor: Luis Cobos
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Patent number: 9045810Abstract: A method for melting steel in an electric arc furnace (EAF). A hot heel is provided in the EAF. Metal scrap is loaded into the EAF. The metal scrap is melted in the EAF. The mass of the hot heel in relation to the mass of the metal scrap that is initially beyond the surface of the hot heel is a certain minimum. This minimum is 0.75 times the relation between the heat required to melt the metal scrap beyond the surface of the hot heel and the heat that can be taken from the hot heel without it being solidified when a theoretical heat balance calculation is applied as defined in a formula.Type: GrantFiled: July 3, 2014Date of Patent: June 2, 2015Assignee: ABB RESEARCH LTD.Inventors: Rebei Bel Fdhila, Jan-Erik Eriksson, Olof Hjortstam, Mohamed Ali Rahmani, Shiva Sander-Tavallaey, Ola Widlund, Hongliang Yang, Xiaojing Zhang
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Patent number: 8651169Abstract: An arc melting furnace apparatus is provided which reduces an operation burden on a worker and shortens working hours. An arc melting furnace apparatus 1 includes a housing 2 having formed therein a melting chamber 2a, a hearth 4 provided within the melting chamber 2a and having a recessed portion 4a, and a heating mechanism 10 for heating and melting a metal material supplied into the recessed portion 4 to generate an alloy ingot. The apparatus comprises a turning member 23 rotatably supported on a supporting member 21 standing within the melting chamber 2a, a perimeter edge of the turning member 23 rotating and moving along the inner surface of the recessed portion 4a to lift the alloy ingot generated in the recessed portion 4a above the hearth 4 and turn it over, and a resilient turn-over assisting member 24 provided above an upper end of the recessed portion 4a.Type: GrantFiled: June 1, 2011Date of Patent: February 18, 2014Assignees: Diavac Limited, Tohoku Techno Arch Co., Ltd.Inventors: Masaki Nagata, Motohiro Kameyama, Yoshihiko Yokoyama, Akihisa Inoue
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Patent number: 8599899Abstract: An agitation device, a melting apparatus, and a melting method for improving melting efficiency of molten metal without contaminating the same. The agitation device is provided with a traveling magnetic field generating unit which is disposed outside a charging tank for storing molten metal and generates, inside the charging tank, a magnetic field that travels downward along the rear sidewall of the charging tank. A flow of the molten metal that rotates longitudinally about an axis approximately parallel to the surface of the molten metal is produced in the molten metal. By charging aluminum cutting chips into the molten metal in which the flow is produced, the aluminum cutting chips move with a downward flow of the molten metal, and are immersed in the molten metal. As a result, melting of the aluminum cutting chips can be accelerated.Type: GrantFiled: October 27, 2009Date of Patent: December 3, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventors: Shinichi Koriyama, Takashi Hirai
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Patent number: 8391331Abstract: 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.Type: GrantFiled: July 1, 2004Date of Patent: March 5, 2013Assignees: Outotec Oyj, SMS Siemag AGInventors: Heinz Eichberger, Karl-Josef Schneider
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Publication number: 20120134384Abstract: This invention concerns an electric arc furnace comprising a chamber suitable for containing molten steel; a roof suitable for covering the chamber and for containing a mass of scrap steel; electrodes suitable for melting the mass of scrap, and means of support on a base. The latter means are such as to support the chamber and permit its oscillation around a horizontal axis of rotation. The roof and the chamber are counterprofiled in correspondence to the respective interface walls to create a rotoidal type coupling with regard to the axis of rotation. The roof, during oscillation of the chamber, remains fixed with regard to the base as well as in a closed position with regard to the chamber.Type: ApplicationFiled: March 31, 2009Publication date: May 31, 2012Applicant: SMS CONCAST ITALIA S.R.L.Inventors: Stefano Miani, Bruno Rubeo
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Patent number: 7815846Abstract: An agitator for applying an alternating field to a melting furnace main body in order to melt a row material to form a melt includes a plurality of magnets, which are arranged so that magnetic lines of force emitted from one of the magnets pass through the melt in the melting furnace main body and return to another magnet, the magnets being fixed to an inclined surface which is inclined by an angle with respect to a horizontal surface, and being rotatable around an axis substantially perpendicular to the inclined surface.Type: GrantFiled: June 30, 2005Date of Patent: October 19, 2010Inventor: Kenzo Takahashi
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Patent number: 6614831Abstract: 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.Type: GrantFiled: July 10, 2001Date of Patent: September 2, 2003Assignee: Process Technology International, Inc.Inventor: Valery G. Shver
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Patent number: 6549557Abstract: An AC arc furnace has a plurality of electrodes arranged inside a furnace chamber enclosed by a shell. Each electrode is electrically connected to an electrode power source in series through corresponding auxiliary electromagnetic coils. The electromagnetic coils are arranged around the furnace shell in a pre-defined geometric pattern proximate the corresponding electrodes so that when each of the electrodes receives power from the power source and generates an arc inside the furnace, external magnetic fields are generated by the corresponding series connectedelectromagnetic coils. The external magnetic fields penetrate the shell to control deflection of the arcs caused by internal magnetic fields.Type: GrantFiled: May 18, 2001Date of Patent: April 15, 2003Assignee: UCAR Carbon Compan, Inc.Inventor: Brian Bowman
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Patent number: 6516019Abstract: It is an object of the present invention to prevent oxidation during the metal melting, by suspending both heating and supply of metal material under the monitoring by measuring the oxygen concentration in the inactive gas atmosphere. A oxidation prevent method of melting metal material by a melting vessel 1 comprising inside a rotatable agitation member 8, having a weighing chamber 4 communicating with a nozzle member 2, and an injection member 9 advanceably and retractably inserting an extremity injection plunger 12 passing through the agitation member 8 in the weighing chamber 4, and the melting vessel being installed on a slant with the nozzle member 2 downside. The space area over the melted metal surface 15a of the melting vessel 1 is made into inactive gas atmosphere. The oxygen concentration in this space area is measured and monitored.Type: GrantFiled: August 8, 2001Date of Patent: February 4, 2003Assignee: Nissei Plastic Industrial Co., Ltd.Inventors: Kiyoto Takizawa, Toshiyasu Koda, Yuji Hayashi, Mamoru Miyagawa
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Patent number: 6477195Abstract: In a process for melting down sponge metal (11) in an electric-arc furnace (1) having at least one electrode (6), the sponge metal (11) is introduced into the electric-arc furnace (1) under formation of at least one sponge metal jet (15) which in the immediate vicinity of an electrode (6) hits the bath level (16) present in the electric-arc furnace (1), and for decarburization and/or intermixing the bath and/or charging energy oxygen is blown into the melt (7).Type: GrantFiled: May 22, 2001Date of Patent: November 5, 2002Assignee: Voest-Alpine Industrieanlagenbau GmbH & Co.Inventors: Peter Mittag, Harald Berger
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Patent number: 6424672Abstract: An electric arc furnace (1), wherein solids are injected into the furnace chamber. The lances (9, 10, 11) are guided through the wall (12) of the electric arc furnace (1) and inserted into the wall of the furnace, whereby at least one lance is associated with each electrode (2, 3, 4), in order to enable a homogenous formation of slag and to inject as great an amount of solids as possible. The lances are distributed in an approximately uniform manner along the periphery of the furnace. The inclination of the lances and thus the angle of injection are selected in such a way that they form an angle of approximately 30-80° in relation to the flow direction of the melting bath and form an angle of approximately 10-30° in relation to the horizontal.Type: GrantFiled: January 11, 2001Date of Patent: July 23, 2002Inventors: Wilfried Stein, Karl Stein
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Patent number: 6400747Abstract: A quadrilateral assembly in an electric arc furnace wall for providing one or more coherent jets into the furnace and for providing preferably a plurality of post combustion oxidant streams into the furnace, preferably for forming a post combustion oxidant sheet.Type: GrantFiled: May 18, 2001Date of Patent: June 4, 2002Assignee: Praxair Technology, Inc.Inventor: Pravin Chandra Mathur
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Patent number: 6400748Abstract: In order to operate an electric arc furnace (1) in optimum conditions, especially in order to build up and maintain a certain intensity of foamed slag, the amount of slag builder fed into the furnace (1) and therefore the power consumption of the furnace (1) is regulated according to the current received by the electrodes (2) in such a way that a maximum amount of slag builder is initially added in order to build up said foamed slag until the amount of current received by the electrodes (2) is reduced. Subsequently, the amount of added slag builder is reduced until the amount of current received reaches a predetermined set value. The theoretical amount of current received is kept constant by reducing or increasing the added amount of slag builder.Type: GrantFiled: January 8, 2001Date of Patent: June 4, 2002Inventors: Wilfried Stein, Karl Stein
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Publication number: 20020021736Abstract: It is an object of the present invention to prevent oxidation during the metal melting, by suspending both heating and supply of metal material under the monitoring by measuring the oxygen concentration in the inactive gas atmosphere. A oxidation prevent method of melting metal material by a melting vessel 1 comprising inside a rotatable agitation member 8,having a weighing chamber 4 communicating with a nozzle member 2, and an injection member 9 advanceably and retractably inserting an extremity injection plunger 12 passing through the agitation member 8 in the weighing chamber 4, and the melting vessel being installed on a slant with the nozzle member 2 downside. The space area over the melted metal surface 15a of the melting vessel 1 is made into inactive gas atmosphere. The oxygen concentration in this space area is measured and monitored.Type: ApplicationFiled: August 8, 2001Publication date: February 21, 2002Applicant: NISSEI PLASTIC INDUSTRIAL CO., LTD.Inventors: Kiyoto Takizawa, Toshiyasu Koda, Yuji Hayashi, Mamoru Miyagawa
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Publication number: 20020001332Abstract: 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.Type: ApplicationFiled: July 10, 2001Publication date: January 3, 2002Inventor: Valery G. Shver
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Publication number: 20010048707Abstract: In a process for melting down sponge metal (11) in an electric-arc furnace (1) having at least one electrode (6), the sponge metal (11) is introduced into the electric-arc furnace (1) under formation of at least one sponge metal jet (15) which in the immediate vicinity of an electrode (6) hits the bath level (16) present in the electric-arc furnace (1), and for decarburization and/or intermixing the bath and/or charging energy oxygen is blown into the melt (7).Type: ApplicationFiled: May 22, 2001Publication date: December 6, 2001Applicant: Voest-Alpine Industrieanlagenbau GmbH & Co.Inventors: Peter Mittag, Harald Berger
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Publication number: 20010043639Abstract: 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.Type: ApplicationFiled: June 5, 2001Publication date: November 22, 2001Inventor: Valery G. Shver
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Patent number: 6289034Abstract: A process for producing metals from a metalliferous feed material in an electric furnace is disclosed. The process includes the steps of forming a molten bath having a metal layer and a slag layer on the metal layer in the furnace and supplying electrical energy to the furnace and converting the electrical energy to thermal energy and thereby contributing to the heat input requirements of the process. The process also includes injecting a carrier gas and a solid carbonaceous material into the molten bath via one or more than one solids injection lance/tuyere and causing molten material to be projected from the molten bath as splashes, droplets, and streams into a space above a nominal quiescent surface of the molten bath and forming a transition zone.Type: GrantFiled: March 21, 2000Date of Patent: September 11, 2001Assignee: Technologies Resources Pty. Ltd.Inventor: Cecil Peter Bates
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Patent number: 6038245Abstract: 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.Type: GrantFiled: May 8, 1998Date of Patent: March 14, 2000Assignee: L'Air Liquide, Societe Anonyme pour L'Etude et L'Exploitation des Procedes Georges ClaudeInventors: Franck Slootman, Nicolas Perrin, Frederic Viraize
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Patent number: 6026113Abstract: Method for the electromagnetic stirring of the liquid metal (14) in direct current electric arc furnaces which include a hearth (35) defined by a floor (13) and by side walls (15), a central cathode (11) cooperating with anodes (12) arranged on the floor (13) of the furnace and fed by a main current (I.sub.0), wherein there is an electromagnetic system generating a magnetic field inside the liquid metal (14) whose vertical (B.sub.z) and radial (B.sub.r) components interact respectively with the radial (J.sub.r) and vertical (J.sub.z) components of the overall current present in the liquid metal (14). The method and device use a first electromagnetic system including at least a first winding (19) through which a current (I.sub.1) flows and operating from inside the floor (13) and the walls (15) of the hearth (35), and a second electromagnetic system generating a secondary induced current (I.sub.3), between adjacent anodes (12), which circulates through the liquid metal (14).Type: GrantFiled: October 14, 1997Date of Patent: February 15, 2000Assignee: Danieli & C. Officine Meccaniche SpAInventors: Milorad Pavlicevic, Anatoly Kolesnichenko, Alfredo Poloni, Cristina Bassi
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Patent number: 5999557Abstract: 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.Type: GrantFiled: June 19, 1998Date of Patent: December 7, 1999Assignee: The Broken Hill Proprietary CompanyInventors: Neil Adrian Molloy, Grant Caffrey
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Patent number: 5956366Abstract: A direct current electric arc furnace for melting or heating raw material or molten material. The furnace 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 also 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 an opposite electrical polarity to the electrical polarity of the top electrode. The furnace includes a mechanism for stirring the molten material in the vessel and guiding the arc in the vessel.Type: GrantFiled: February 26, 1997Date of Patent: September 21, 1999Assignee: NKK Steel Engineering, Inc.Inventors: Hiroshi Shimizu, Joseph L. Hake, Richard L. Cook
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Patent number: 5946340Abstract: A process for smelting metallic raw materials in a shaft furnace having beds of metallic raw material and coke comprises injecting concurrently into the shaft furnace (1) a mixture of flue gases and oxygen at a subsonic velocity and (2) preheated oxygen at supersonic velocity wherein the supersonic velocity oxygen is injected into the coke bed.Type: GrantFiled: February 6, 1998Date of Patent: August 31, 1999Assignee: Georg Fischer Disa Engineering AGInventors: Josef Ramthun, Albert Koperek
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Patent number: 5936996Abstract: A furnace plant which at least one furnace vessel with side walls and a bottom and at least one heat source which by radiation and convection heats molten metal and/or solid metal present in the furnace vessel. At least one two- or multiphase electromagnetic side stirrer is arranged in or near the wall of the furnace vessel to act through the wall and apply a stirrer field to the molten metal. The side stirrer comprises at least two phase windings arranged around an iron core having a vertical extent, H, which essentially covers the region, D.sub.max, between the bottom and the upper surface of the molten metal at a maximum bath depth used in the furnace 15 vessel. The side stirrer is arranged with a pole pitch.tau. which exceeds twice the distance from the iron core to the molten metal, .tau.>2 dw.Type: GrantFiled: January 6, 1998Date of Patent: August 10, 1999Assignee: Asea Brown Boveri ABInventors: Magnus Eidem, Per Henriksson, Lars Karlsson, Lars Nordekvist, Petter Oscarsson, Gunnar Sellberg, Gote Tallback
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Patent number: 5822357Abstract: 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.Type: GrantFiled: November 9, 1995Date of Patent: October 13, 1998Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventors: Frank Slootman, Nicolas Perrin, Frederic Viraize
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Patent number: 5802097Abstract: 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 witType: GrantFiled: January 17, 1996Date of Patent: September 1, 1998Assignee: Danieli & C. Officine Meccaniche spAInventors: Gianni Gensini, Matteo Losciale, Corrado De Cecco
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Patent number: 5550857Abstract: A waste vitrification apparatus (10) having rotatable mixer impeller (16) functioning as a shaft electrode (60) and metallic vessel (14) functioning as a vessel electrode (62). A stream (12) of waste material and vitrifiable material are mixed and melted in the vessel (14) for vitrification. The waste vitrification method converts a feed stream (12) by mixing the feed stream into a glass melt (13) and melting glass batch of the feed stream (12) to form a foamy mass. The stream is dispersed by the impeller (16) to form a foam which is then densified in a settling zone (22), recovered through a spout (24) and solidified in storage containers. An adjuster adjusts the location of the mixing impeller (16) in the vessel (14) to change the depth of the settling zone (22). The impeller (16) is mounted on a drive shaft (18) having a recirculating coolant flow.Type: GrantFiled: June 7, 1995Date of Patent: August 27, 1996Assignee: Stir-Melter, Inc.Inventor: Ray S. Richards
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Patent number: 5513207Abstract: An aluminum can melting furnace in which a slip stream of molten material is diverted from a main molten bath in the furnace, a vortex is formed in the diverted slip stream, and thin walled aluminum can feedstock is introduced into the vortex. The feedstock is immediately drawn under the surface of the vortex in the slip stream so the feedstock melts before it has a chance to oxidize. Hydrocarbons which are introduced with the feedstock are flash vaporized in the vortex. The hydrocarbon vapors are captured and conducted to the furnace burner where they are burned to increase the efficiency of the operation and reduce the pollution generated by the process.Type: GrantFiled: January 9, 1995Date of Patent: April 30, 1996Assignee: Thermal Kinetic Systems, Inc.Inventor: Mukund N. Kavia
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Patent number: 5467366Abstract: 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.Type: GrantFiled: October 18, 1994Date of Patent: November 14, 1995Assignee: Messer Griesheim GmbHInventors: Herbert Wilhelmi, Eberhard Steinmetz, Klaus Peters
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Patent number: 5444733Abstract: Electric arc furnace with alternative sources of energy, which functions with direct current or alternating current and comprises at least one lance (12) to inject pure or combined oxygen above the bath (16) and a plurality of tuyeres (13) positioned in the hearth of the furnace (10) to inject oxygen below the bath, the tuyeres (13) being cooled by a peripheral movement of a cooling mixture consisting of at least one gas having a high cooling power (methane, butane, inert gases, etc.) and of at least one diluting gas (nitrogen, carbon dioxide), pipes (15) being included to introduce additives and powdered coal, post-combustion burners (28) possibly being comprised, the tuyeres (13) including an oxygen delivery pipe (18) having a diameter greater than 8 mm., the oxygen pressure being capable of being modulated according to the working steps, there being a constant minimum pressure of delivery.Type: GrantFiled: May 4, 1994Date of Patent: August 22, 1995Assignee: Danieli & C. Officine Meccaniche SpAInventors: Giovanni Coassin, Corrado De Cecco, Gianni Gensini, Sergio Gerussi
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Patent number: 5381441Abstract: A direct current arc furnace is described with a cathodic electrode held in the center of the melting vessel and an anodic bottom electrode arrangement in the vicinity of an electrically conductive lower vessel from the vessel wall to the melt. The current supply and removal takes place on one side via leads to a rectifier power supply set up in spaced manner alongside the furnace. The lower vessel is connected in several quadrants with leads and in the vicinity of each quadrant a connecting plate is provided on the furnace wall. Close below the arc the power supplies are led in a horizontal plane to the furnace wall. The current intensity for the quadrants of the lower vessel adjacent to the rectifier power supplies is lower than that of the power supplies to the remaining quadrants. The spacings of the connecting plates for the quadrant areas can be unequal.Type: GrantFiled: December 1, 1993Date of Patent: January 10, 1995Assignee: Deutsche Voest-Alpine Industrieanlagenbau GmbHInventor: Edgar Nix
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Patent number: 5381440Abstract: A bottom electrode (1) for d.c. arc furnaces with metal rods (3) arranged on the base plate (2) of the bottom electrode and with conductive and nonconductive layers formed of high temperature-resistant refractory material introduced between them. An upper layer formed of conductive bricks (8), a middle layer formed of conductive, monolithic lining material (9), and a lower layer formed of a nonconductive insulating mass (10) are introduced via the circumference of the base plate (2). In the area of the bricks (8), the metal rods (3) are additionally embedded in a nonconductive mass (11). To introduce inert gases to purge the melt through the bottom electrode (1), the metal rods (3) are provided with a cored hole and, in the upper part, with a number of radial holes in order for the purging gases to be able to be discharged in the area of the bricks (8), or blind holes (13), which are connected to a second purging gas line (13a), are introduced into the lower part of the lined bottom electrode (1).Type: GrantFiled: July 9, 1993Date of Patent: January 10, 1995Assignee: Man Gutehoffnungshutte AktiengesellschaftInventor: Manfred Schubert
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Patent number: 5375139Abstract: The present invention discloses an electric arc furnace wherein the natural gas flow is artificially altered to obtain beneficial effects. By injecting gases, preferably but not necessarily containing oxygen, into the electric arc furnace in the vicinity of the electrode port, the injected gases move vertically downward near the furnace center toward the bath. This process of injecting gases downward around the electrode enables the natural circulation in the furnace to be reversed. When gases reach the bath level, they disperse outward penetrating the scrap and depositing heat energy thereon. By preheating the scrap in this manner production is increased and emissions released into the off-gas system can be reduced.Type: GrantFiled: February 26, 1993Date of Patent: December 20, 1994Inventor: Manfred Bender
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Patent number: 5373530Abstract: 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.Type: GrantFiled: May 13, 1994Date of Patent: December 13, 1994Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventor: Nicolas Perrin
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Patent number: 5319669Abstract: An apparatus for processing various hazardous waste materials by melting in a vessel for subsequent solidification is disclosed which includes a seal for the cover thereof. Melter includes a high-speed mixing impeller powered by a drive shaft which extends through an opening in the cover. The vessel is electrically heated by discharge of electrical energy through the melt contained in the vessel. In one embodiment the impeller and shaft are included in the electrical heating circuit. A shaft seal engages the shaft at a point spaced from the cover. An axially extensible seal seals a space bounded by the shaft seal and the opening in the cover. Purge gas is supplied to the sealed space to provide positive gas flow from the sealed space into the vessel. A cold wall transport duct for off-gas porting is disclosed. A bottom drain structure including a sleeve and plug is also disclosed. The output of the melter may be subsequently heated in a holding tank to refine the output.Type: GrantFiled: January 22, 1992Date of Patent: June 7, 1994Assignee: Stir-Melter, Inc.Inventors: Stephen F. Cox, Ray S. Richards
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Patent number: 5297160Abstract: An arc furnace comprising a furnace vessel having a transverse axis and a central axis, electrodes disposed on a graduated circle, the electrodes projecting into the furnace vessel parallel to the central vertical axis, the electrodes are mounted on an electrode holding device of three supporting columns and three supporting arms, the center is located on the transverse axis at a predetermined distance from the center, the transverse axis being collinear with the middle one of the supporting arms, an electrode is disposed closest to the supporting columns at the intersection of the transverse axis and the graduated circle, and the other electrodes are disposed on the graduated circle an angle .alpha.=<110.degree. with the electrode at the center of the circle.Type: GrantFiled: January 10, 1992Date of Patent: March 22, 1994Assignee: Mannesmann AktiengesellschaftInventor: Joseph F. Kroker
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Patent number: 5257280Abstract: The present invention has been devised to obtain a metallurgical effect by introducing refining gas into a molten metal in a metallurgical vessel and stirring the molten metal sufficiently by convection, and to improve durability of one nozzle or a few nozzles for introducing the refining gas. At a predetermined position of a furnace bottom onto which a ramming mass is provided, a few cylindrical refractory sleeves are disposed close to the upper face of the furnace bottom from the lower portion thereof. In each cylindrical refractory sleeve a gas introducing nozzle, which introduces the refining gas, is disposed in such a manner that it can be drawn out downwardly for replacement.Type: GrantFiled: September 10, 1991Date of Patent: October 26, 1993Assignee: Kawasaki Refractories Co., Ltd.Inventors: Nobuyuki Mimura, Minoru Ususaka
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Patent number: 5166950Abstract: Process for melting a furnace charge, with post-combustion of the smokes by njecting an oxygenated gas in the furnace atmosphere as a series of jets flowing according to a tangential component in the space between electrodes and cylindrical furnace partition of the furnace, in a direction of injection so as to produce a rotary gas current about the vertical axis of the furnace and preferably in at least two series as two stepped levels to produce gas currents which rotate in opposite directions. Applications to electrical furnaces for the production of steel or ferro-alloys.Type: GrantFiled: June 19, 1991Date of Patent: November 24, 1992Assignee: L'Air Liquide, Societe Anonyme pour Etude et l'Exploitation des ProcedesInventors: Dominique Jouvaud, Nicolas Perrin
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Patent number: 5052018Abstract: An anode for a d.c. arc furnace is described. The furnace area receiving the melt (2) is provided on the inside with an electrically conductive, refractory lining (8,9,11). The latter is electrically connected to a conductor (12) located on the outside and which has a cylindrical construction and is placed around the electrically conductive lining. The conductor is advantageously fixed to the inside of the steel jacket (3) of the furnace.Type: GrantFiled: October 12, 1989Date of Patent: September 24, 1991Assignee: Deutsche Voest-Alpine Industrieanlagen GmbHInventor: Dane Meredith
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Patent number: 4903948Abstract: The invention comprises a metallurgical vessel, more particularly an electric arc furnace, having means for introducing inert stirring (purging) gases into a metal melt. The vessel has an outer sheet metal jacket, a refractory lining, and means for introducing stirring gases into the melt being disposed in the furnace hearth, which comprises a permanent lining of refractory bricks and a wear lining of a refractory ramming mass. The means for introducing the stirring gases are disposed in the permanent lining.Type: GrantFiled: December 12, 1988Date of Patent: February 27, 1990Assignee: Thyssen Stahl AGInventors: Josef Wolf, Fritz-Jurgen Strunck
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Patent number: 4873063Abstract: Apparatus for producing crystalline ribbons of a material from a "crucible-less" configuration of bodies of the material including possible deposition on a substrate. Means for capacitively coupling electromagnetic energy into a source body of material are provided to appropriately induce electrical current gradients in order to control and restrict the molten zone and supress net loss of the heat of fusion from the balance of the ribbon-like body. The melt zone is replenished from any direction with ribbon or a bulk source to sustain the shape and size of the growing ribbon-like body. The heat of crystallization is selectively removed by a heat sink from one end of the melt zone in a direction substantially perpendicular to the direction of pulling.Type: GrantFiled: March 28, 1988Date of Patent: October 10, 1989Inventor: Carl E. Bleil
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Patent number: 4862477Abstract: An electric furnace for melting batch material and mixing the molten material. Electrodes are used to create what is believed to be electromagnetically stirred active melting areas within the molten material. The molten material is stirred by moving the electrodes and furnace shell with respect to each other while the electrodes are positioned in a corona discharge relationship to the melt. This can be implemented by rotating the electrodes or the shell or by a compound movement caused by moving the electrode support arms toward and away from the center of the vessel in timed relationship to pivotal movement of electrode support arms so as to cause the electrode tips to traverse an arcuate path concentric with the center of the vessel. In a shallow immersion, simple pivoting of the electrode support arms is beneficial. To further decrease the dead area within a furnace vessel utilizing electrodes which are shallowly immersed, the vessel can be made polygonal as opposed to circular in lateral cross section.Type: GrantFiled: September 1, 1988Date of Patent: August 29, 1989Assignee: Manville CorporationInventors: Leonard E. Olds, Michael D. Peterson, Jean P. Martin
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Patent number: 4747582Abstract: Manipulator for guiding of devices for treatment of heats in furnaces, ladles and the like, e.g. lances for injection of oxygen through a door (3) of an electromelting furnace, consisting of a feed table (19), on which one or several devices (24,29) are arranged displaceable mechanically guided in its length direction by means of one or several feed devices, at which the feed table (19) is movable mechanically guided between an advanced position at a work point (14), where the feed table (19) is immediately in front of the furnace door (3) or the like, at which the devices (24,29) can be inserted into the furnace (2) and possibly lowered down into the heat, and a retracted position, where the feed table (19) is removed from the furnace door (3).Type: GrantFiled: June 18, 1986Date of Patent: May 31, 1988Inventors: Sven E. Bergstrom, Peter Gossas
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Patent number: 4726033Abstract: A process to improve electric arc furnace steelmaking. The efficiency increase is due to the metal-slag stirring that is produced by bottom gas injection through gas permeable ceramic elements. The permeable elements are not penetrated by the liquid metal, which does not stop the gas flow.The process is carried out in combination with a furnace charging door stopper device. The device avoids liquid ejections through the furnace charging door during the injection periods. The electric arc furnace steelmaking generalized practices are more effective when the molten metal is being stirred by gas injection, by increasing the metal-slag and the slag-atmosphere interphase area. When the stirring gas is natural gas, the process conditions, oxidizing or reducing, are reinforced according to the slag in the bath.Type: GrantFiled: January 29, 1986Date of Patent: February 16, 1988Inventors: Arturo Lazcano-Navarro, Gregorio Vargas-Gutierrez, Carlos Maroto-Cabrera
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Patent number: 4528673Abstract: A metallurgical ladle furnace has a ladle for containing the melt, an arcing electrode positioned on the ladle's axis, and a melt electrode in the ladle's lower portion and substantially symmetric with respect to the arcing electrode. DC power applied to the electrodes results in an arc between the arcing electrode and the melt for heating the melt and incidentally causing the melt to stir in vertical directions, the melt moving downwardly in the middle below the arc, upwardly along the walls of the melt and inwardly towards the arc. A DC powered coil surrounds the ladle horizontally at half the ladle's height or higher, around the upper portions of the melt. The field of this coil in cooperation with a DC flow in the melt caused by the current flow between the electrodes, provides a substantially tangential stirring force on the melt which is in addition to the stirring force of the electrode current in the melt.Type: GrantFiled: September 8, 1983Date of Patent: July 9, 1985Assignee: ASEA AktiebolagInventor: Sven-Einar Stenkvist
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Patent number: 4443879Abstract: The present invention relates to a reduction furnace with a split furnace body, particularly suited for production of ferro alloys, pig iron or calcium carbide. Furnaces of such types are provided with a furnace pot equipped with an internal refractory lining anchored to the furnace wall by means of anchoring elements. According to the present invention the refractory lining of at least the upper section of the split furnace body comprises a plurality of individual, pre-fabricated elements which are removably arranged at least on the upper section. Each unit comprises preferably a rear plate of steel, pig iron or similar material and one or more anchoring ribs or bolts extending horizontally out from and rigidly secured to the rear plate. The anchoring ribs provide a hold for the refractory lining on the rear plate. The separate units are suspended at least from the upper segment by means of simple support means.Type: GrantFiled: May 23, 1983Date of Patent: April 17, 1984Assignee: Elkem a/sInventor: Harald Krogsrud
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Patent number: 4371392Abstract: Refining method of molten metal which employs a refining apparatus provided with a tiltable refining vessel, a tuyere formed therein for blowing inert gas and/or flux or further sometimes additive alloy component(s), with the aid of inert gas into the molten metal, and a suitable number of electrodes for heating the molten metal and flux, for the purpose of performing a first refining process of carrying out the heating of the molten metal and the flux with the electrodes and a second refining process of tilting the vessel for blowing into the molten metal insert gas and others from the tuyere, whereby harmful or unnecessary metallic and/or non-metallic impure components can be removed for improving the quality of the article.Type: GrantFiled: July 20, 1981Date of Patent: February 1, 1983Assignee: Daido Tokishuko Kabushiki KaishaInventors: Kazumasa Hasegawa, Minao Ito, Saburo Sugiura, Kiyoichi Yamano, Shizunori Hayakawa
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Patent number: 4336411Abstract: A molten steel ladle has a melt electrode in its side wall near its bottom so a DC arc can be formed with molten metal in the ladle for heating and stirring the metal, the ladle being also used for casting. The melt electrode is free from the ladle's casting nozzle and the outside of the ladle is free from projections extending beyond the ladle's trunions, so the ladle can be crane-carried in the usual manner.Type: GrantFiled: February 24, 1981Date of Patent: June 22, 1982Assignee: ASEA AktibolagInventors: Bertil Hanas, Sven-Einar Stenkvist