Gas Injection Below Surface Of Melt Patents (Class 75/501)
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Patent number: 5246482Abstract: The disclosure relates to a molten metal producing and refining method which does not damage the apparatus, realizes a stable and high second combustion rate, and is capable of effectively recovering heat generated by the second combustion. The method comprises introducing a metal-containing material, a carbonaceous material, a flux and O.sub.2 gas into a furnace. The carbon which dissolves into the metal bath in the furnace from the carbonaceous material is combusted with the O.sub.2 gas to generate heat and CO gas. The CO gas is subjected to the second combustion with the O.sub.2 gas to additionally generate heat, and the metal-containing material is melted and refined by both the generated heat and carbon. The method is characterized in that O.sub.2 gas or O.sub.2 -containing gas is blown into the furnace through large-diameter tuyeres installed near the bottom of the furnace and a part of the O.sub.Type: GrantFiled: September 25, 1991Date of Patent: September 21, 1993Assignee: Kawasaki Jukogyo Kabushiki KaishaInventors: Keikichi Murakami, Mitsuharu Kishimoto, Yoshio Uchiyama, Kenichi Yajima, Masaru Takiura, Satoshi Tatsuta, Yukihiko Koza, Sumio Satoh
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Patent number: 5139568Abstract: A process for the continuous production of an iron-carbon alloy utilizing an enclosed reactor (10) capable of limiting the ingress and egress of atmospheric gases and gas reaction products respectively. A solid mineral material (20) containing iron carbide and at least trace amounts of iron oxide, and having a weight ratio of at least about 2:1 or greater, is fed into a molten bath (12) of metallic material in the reactor (10). The molten metallic material is simultaneously reacted with oxygen at a temperature sufficient to generate carbon monoxide as a reaction product. The oxygen is preferably injected into the molten metallic material to facilitate the reaction of the oxygen with carbon from the iron carbide to form the carbon monoxide. The carbon monoxide subsequently enters a vapor space (17) of the reactor (10) above the molten bath (12), and further reacts with oxygen to generate carbon dioxide and heat.Type: GrantFiled: October 3, 1991Date of Patent: August 18, 1992Assignee: Cargill, IncorporatedInventor: Gordon W. Geiger
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Patent number: 5069715Abstract: The present invention relates to an overall direct smelting process which provides for separating the carburization function from the heating function to permit separate control of the individual functions. One embodiment of the smelting reactor is divided into a carburization/smelting section and a heating section with a substantial recirculation of the molten product from the heating section back to the carburization/smelting section. The heating section also serves as a slag/metal separation section. Carburization is achieved by injection of solids (fine coal mixed with slagging agents), where desired. Gas generating solids or inert gases are injected into a lift pipe to provide a motive force for circulation of the molten metal. The circulation rate through the system is a function of the injected solid composition, the mass flow rate of the solids injected into the lift pipe and the lift pipe geometry.Type: GrantFiled: April 2, 1990Date of Patent: December 3, 1991Assignee: Regents of the University of MinnesotaInventor: Kenneth J. Reid
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Patent number: 5000784Abstract: A method for smelting reduction of iron ore comprises the steps of: preheating and prereducing iron ore; charging said preheated and prereduced iron ore, carbonaceous material and flux into a smelting reduction furnace; blowing oxygen gas through a top blow oxygen lance having decarburizing nozzles and post-combustion nozzles into said smelting reduction furnace, an end of said top blow oxygen lance being arranged between an upper side level of a slag layer and a lower side level of said slag layer; blowing a stirring gas through at least one side tuyere placed in side wall of said smelting furnace and at least one bottom tuyer placed in bottom wall of said reduction furnace so that at least part of said stirring gas introduced through at least one said side tuyere hits a swollen portion of the molten metal by said stirring gas introduced through at least one said bottom tuyere; and controlling a flow rate of said oxygen gas and said stirring gas blown in said smelting reduction furnace so that an OD of infurType: GrantFiled: November 28, 1988Date of Patent: March 19, 1991Assignee: NKK CorporationInventors: Kenji Takahashi, Katsuhiro Iwasaki, Shigeru Inoue, Haruyoshi Tanabe, Masahiro Kawakami, Kenzo Yamada, Osamu Terada
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Patent number: 4985068Abstract: Energy for melting iron oxide or wustite is supplied by pre-heated natural gas which is combusted with oxygen in gaseous form and the oxygen contained in the preheated feed materials. Such combustion produces carbon monoxide and hydrogen gas, thus the combustion products are carbonizing to molten iron. The carbon monoxide and hydrogen evolved at the surface of the molten metal is post-combusted above the bath to form a mixture of carbon monoxide, carbon dioxide, hydrogen, steam and nitrogen. The heat generated by this post-combustion is sufficient to supply the energy for all chemical reaction requirements as well as to melt the wustite charge or smelt the preheated iron oxide charge.Type: GrantFiled: November 27, 1989Date of Patent: January 15, 1991Assignee: Midrex International BV, Rotterdam, Zurich BranchInventors: Glenn E. Hoffmann, John C. Scarlett
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Patent number: 4957545Abstract: Described herein is a smelting reduction process for smelting and reducing an iron oxide material by introducing same into a smelting reduction furnace together with a solid carbonaceous material, a fluxing agent and an oxygen-containing gas, process comprising: subjecting part or all of the solid carbonaceous material to primary combustion using an oxygen-containing gas with an oxygen content corresponding to a theoretical air ratio of 0.4 to 0.9: separating the resulting reducing gas from combustion residue of the solid carbonaceous material; and introducing the reducing gas into a smelting reduction furnace to effect secondary combustion with supply of a separately introduced oxygen-containing gas for smelting and reducing said iron material.Type: GrantFiled: January 27, 1989Date of Patent: September 18, 1990Assignee: Kabushiki Kaisha Kobe Seiko ShoInventors: Akihide Hikosaka, Tsuyoshi Mimura, Tomio Suzuki, Takeo Yoshigae, Shuzo Itoh
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Patent number: 4944799Abstract: This invention relates to a method of producing stainless molten steel by a smelting reduction treatment - decarburization treatment of Cr raw materials such as Cr ores, Cr ore pellets and so on consecutively and at high treating speed in one container. In the smelting reduction, an inert gas is blown from bottom tuyeres to form an upheaving part of the molten metal on its surface and the inert gas is blown to this upheaving part. The molten metal is thereby caused to disperse into a region of the slag where the Cr materials float, so that the reduction of Cr is accelerated by C. On the other hand, decarburizing O.sub.2 is blown into the molten metal from a top lance, while O.sub.Type: GrantFiled: April 25, 1989Date of Patent: July 31, 1990Assignee: NKK CorporationInventors: Haruyoshi Tanabe, Masahiro Kawakami, Kenji Takahashi, Katsuhiro Iwasaki, Shigeru Inoue
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Patent number: 4936908Abstract: A method for smelting and reducing iron ores comprises the steps of: the step of preheating and prereducing iron ores; the step of charging the preheated and prereduced iron ores into a smelting reduction furnace; the step of charging carbonaceous material and fluxing material into the smelting reduction furnace; the step of blowing in oxygen gas into the smelting reduction furnace through a top-blow oxygen lance having decarbonizing nozzles and post combustion nozzles; and the step of blowing in stirring gas through side and bottom tuyeres set respectively in a side wall and a bottom of the smelting reduction furnace.Type: GrantFiled: September 19, 1988Date of Patent: June 26, 1990Assignee: NKK CorporationInventors: Kenji Takahashi, Katsuhiro Iwasaki, Shigeru Inoue, Haruyoshi Tanabe, Masahiro Kawakami, Kenzo Yamada, Ichiro Kikuchi
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Patent number: 4935054Abstract: This invention relates to a method of checking flying losses of ores and coal when they are charged for carrying out smelting reduction of Cr ores and iron ores. In the invention, the raw materials are charged into the furnace through a chute extending nearly a mouth of the furnace or connected to a furnace body. Further, while gas is jetted toward an outside of the chute from a nozzle provided in an circumferential direction of an inside nearly the end of the chute, thereby to enable to exactly check the flying losses of the raw materials.Type: GrantFiled: January 3, 1989Date of Patent: June 19, 1990Assignee: NKK CorporationInventors: Haruyoshi Tanabe, Masahiro Kawakami, Kenji Takahashi, Katsuhiro Iwasaki, Shigeru Inoue, Hitoshi Kawata
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Patent number: 4913734Abstract: The hereinproposed method and furnace provide for preliminary building up of melt in a melting pot (10) of a rectangular shape in the horizontal section, delivery of an oxygen-containing gas (3) into the melt below its surface level through tuyeres (13) with nozzles (14) installed in the longer walls of the melting pot (10) creating two melt zones: an upper zone (9) loaded with solid carbon fuel (2) in an amount sufficient for providing a volumetric concentration of said fuel within 0.5 to 50% of the melt volume in said zone (9), wherein said concentration is maintained by subsequent concurrent loading of iron-bearing material (1) and solid carbon fuel (2), and a lower zone (8) consisting of a layer of slag (4) and a layer of ferrocarbon intermediate product (5) said layers being discharged separately through channels (17 and 18) made in the counterproposed short walls of the melting pot (10).Type: GrantFiled: October 5, 1988Date of Patent: April 3, 1990Assignee: Moskovsky Institut Stali I splavovInventors: Vladimir A. Romenets, Alexandr B. Usachev, Alexei A. Ugarov, Valentin P. Bystrov, Valery S. Valavin, Vasily R. Grebennikov, Anatoly B. Glovatsky, Gennady L. Gursky, Dmitry I. Ryzhonkov, Alexandr D. Vaskevich, Valentina M. Chizhikova, Alexandr D. Yatsenko-Zhuk, Vladimir G. Guglya, Alexandr M. Pozhivanov, Evgeny F. Vegman, Nikolai A. Tulin, Stanislav V. Kremenevsky, Andrei V. Vanjukov, deceased