Abstract: An electric furnace with energy utilization efficiency at a low cost. In an electric furnace, a preheating chamber 2 with a melting chamber 1 is used to preheat iron scrap x, an exhaust gas generated in melting chamber 1 is passed through preheating chamber 2 filled with the iron scrap x to preheat the iron scrap x, the iron scrap x descends in the preheating chamber 2 to be supplied into melting chamber 1, and the iron scrap x is melted to obtain molten iron m. The iron scrap x is charged into preheating chamber 2 so that bulk density is not less than 0.50 t/m3 and less than 1.00 t/m3 and an iron scrap filling ratio HSC/HSF in the preheating chamber 2 is 0.5 to 0.8. A carbonaceous material is used for melting the iron scrap x, and oxygen and the carbonaceous material are blown into the melting chamber.

Abstract: A method for manufacturing molten iron by melting a cold iron source in an electric arc furnace having a carbonaceous material-injecting device. The method includes, in the carbonaceous material-injecting device, while a carbonaceous material is injected with a carrier gas through a central portion of the carbonaceous material-injecting device, injecting a fuel and a combustion-supporting gas through respective outer peripheral portions of the carbonaceous material-injecting device. The carbonaceous material injected through the central portion passes through a cylindrical combustion flame generated by a combustion reaction between the fuel and the combustion-supporting gas and is injected into molten slag and molten iron.

Abstract: A low-sulfur coal production method having an excellent desulfurization effect includes bringing coal into contact with a chemical material that is a mixed solution of hydrogen peroxide and acetic anhydride to remove sulfur in the coal. It is preferred that the molar ratio of the acetic anhydride to the hydrogen peroxide is 0.5 to 12.0 inclusive. It is preferred that the acetic anhydride is mixed with the hydrogen peroxide before the chemical material is brought into contact with the coal and the chemical material is brought into contact with the coal after 10 minutes or more has elapsed since the mixing.

Abstract: A method for producing low-sulfur coal having an excellent desulfurization effect. In the production method, coal is brought into contact with a chemical agent that is a mixed solution of hydrogen peroxide and acetic acid to remove sulfur in the coal. It is preferred that the molar ratio of the acetic acid to the hydrogen peroxide ((acetic acid)/(hydrogen peroxide)) is 1.2 to 60.0 inclusive. It is preferred that the acetic acid is mixed with the hydrogen peroxide before the chemical agent is brought into contact with the coal and the chemical agent is brought into contact with the coal after 30 minutes or more has elapsed since the mixing is performed.

Abstract: Provided is an auxiliary burner for an electric furnace that has high iron scrap heating effect by appropriately and efficiently burning a solid fuel such as coal together with a gas fuel. An auxiliary burner for an electric furnace 100 has a structure in which a solid fuel injection tube 1, a gas fuel injection tube 2, and a combustion-supporting gas injection tube 3 are coaxially arranged in order from the center. The front end of the solid fuel injection tube 1 is located inside the gas fuel injection tube 2 to form, between the front end of the solid fuel injection tube 1 and the front end of the gas fuel injection tube 2, a first space 4 for solid fuel and gas fuel premixing surrounded by the front end portion of the gas fuel injection tube 2.

Abstract: A gas separation and recovery method is provided. Based on the fact that a gas adsorbent has differing adsorption and desorption characteristics depending on the affinities and pressures of gas species, and gases of different species are desorbed at different timings, a target gas component is separated and recovered from a source gas by a pressure swing adsorption process in such a manner that a desorption step is divided into, for example, two time periods and desorbed gases are recovered separately in the respective time periods. In this manner, when gas 1 and gas 2 having different desorption timings are adsorbed to an adsorbent, a gas rich in gas 1, and a gas rich in gas 2 may be recovered separately from each other. Thus, it becomes possible to separate and recover selectively a target gas component with high concentration.

Abstract: An auxiliary burner for an electric furnace capable of increasing and homogenizing the heating effect of iron scrap by suitably and efficiently burning solid fuel along with gas fuel. Auxiliary burner 100 for an electric furnace comprises a solid fuel injection tube 1, a gas fuel injection tube 2, and a combustion-supporting gas injection tube 3 in the stated order from the center side, all arranged coaxially, and is characterized in that: a combustion-supporting gas flow path 30 of the 10 combustion-supporting gas injection tube 3 is provided with a plurality of swirl vanes 4 for swirling the combustion-supporting gas, and the angle ? formed between the swirl vanes 4 and the burner axis is 5° or more and 45° or less.

Abstract: Provided is a cutting machine that cuts a high-temperature moving object to be cut while moving in synchronization with the movement of the object to be cut, and that is capable of effectively protecting itself from the heat of the object to be cut and effectively utilizing the heat. A cutting machine for cutting a high-temperature moving object to be cut while moving in synchronization with the movement of the object to be cut, comprising: a cutter configured to cut the object to be cut; a movement device configured to move the cutting machine in synchronization with the object to be cut; a water-cooling plate configured to cool the cutting machine; and a thermoelectric power generation device including a thermoelectric element for converting the heat of the object to be cut into electric energy, wherein the water-cooling plate also serves to cool a low-temperature side of the thermoelectric element.

Abstract: Provided is an auxiliary burner for an electric furnace capable of increasing and homogenizing the heating effect of iron scrap by suitably and efficiently burning solid fuel along with gas fuel. This auxiliary burner 100 for an electric furnace comprises a solid fuel injection tube 1, a gas fuel injection tube 2, and a combustion-supporting gas injection tube 3 in the stated order from the center side, all arranged coaxially, and is characterized in that: a flow path 30 of the combustion-supporting gas injection tube 3 is provided with a plurality of swirl vanes 4 for swirling the combustion-supporting gas, and a flow path 20 of the gas fuel injection tube 2 is provided with a plurality of swirl vanes 5 for swirling the gas fuel; and the angle ?1 of the swirl vanes 4 and the ?2 of the swirl vanes 5 satisfy the relationship ?1<?2.

Abstract: Provided is a cutting machine that cuts a high-temperature moving object to be cut while moving in synchronization with the movement of the object to be cut, and that is capable of effectively protecting itself from the heat of the object to be cut and effectively utilizing the heat. A cutting machine for cutting a high-temperature moving object to be cut while moving in synchronization with the movement of the object to be cut, comprising: a cutter configured to cut the object to be cut; a movement device configured to move the cutting machine in synchronization with the object to be cut; a water-cooling plate configured to cool the cutting machine; and a thermoelectric power generation device including a thermoelectric element for converting the heat of the object to be cut into electric energy, wherein the water-cooling plate also serves to cool a low-temperature side of the thermoelectric element.

Abstract: A gas separation and recovery method is provided. Based on the fact that a gas adsorbent has differing adsorption and desorption characteristics depending on the affinities and pressures of gas species, and gases of different species are desorbed at different timings, a target gas component is separated and recovered from a source gas by a pressure swing adsorption process in such a manner that a desorption step is divided into, for example, two time periods and desorbed gases are recovered separately in the respective time periods. In this manner, when gas 1 and gas 2 having different desorption timings are adsorbed to an adsorbent, a gas rich in gas 1, and a gas rich in gas 2 may be recovered separately from each other. Thus, it becomes possible to separate and recover selectively a target gas component with high concentration.

Abstract: Provided is an auxiliary burner for an electric furnace capable of increasing and homogenizing the heating effect of iron scrap by suitably and efficiently burning solid fuel along with gas fuel. This presently disclosed auxiliary burner 100 for an electric furnace comprises a solid fuel injection tube 1, a gas fuel injection tube 2, and a combustion-supporting gas injection tube 3 in the stated order from the center side, all arranged coaxially, and is characterized in that: a combustion-supporting gas flow path 30 of the combustion-supporting gas injection tube 3 is provided with a plurality of swirl vanes 4 for swirling the combustion-supporting gas, and the angle ? formed between the swirl vanes 4 and the burner axis is 5° or more and 45° or less.

Abstract: Provided is an auxiliary burner for an electric furnace capable of increasing and homogenizing the heating effect of iron scrap by suitably and efficiently burning solid fuel along with gas fuel. This auxiliary burner 100 for an electric furnace comprises a solid fuel injection tube 1, a gas fuel injection tube 2, and a combustion-supporting gas injection tube 3 in the stated order from the center side, all arranged coaxially, and is characterized in that: a flow path 30 of the combustion-supporting gas injection tube 3 is provided with a plurality of swirl vanes 4 for swirling the combustion-supporting gas, and a flow path 20 of the gas fuel injection tube 2 is provided with a plurality of swirl vanes 5 for swirling the gas fuel; and the angle ?1 of the swirl vanes 4 and the ?2 of the swirl vanes 5 satisfy the relationship ?1<?2.

Abstract: Provided is an auxiliary burner for an electric furnace that has high iron scrap heating effect by appropriately and efficiently burning a solid fuel such as coal together with a gas fuel. An auxiliary burner for an electric furnace 100 has a structure in which a solid fuel injection tube 1, a gas fuel injection tube 2, and a combustion-supporting gas injection tube 3 are coaxially arranged in order from the center. The front end of the solid fuel injection tube 1 is located inside the gas fuel injection tube 2 to form, between the front end of the solid fuel injection tube 1 and the front end of the gas fuel injection tube 2, a first space 4 for solid fuel and gas fuel premixing surrounded by the front end portion of the gas fuel injection tube 2.

Abstract: A method for blowing oxygen in a converter uses a top-blown lance having a Laval nozzle installed on its tip. The Laval nozzle has a back pressure of the nozzle Po(kPa) satisfying a formula, Po=FhS/(0.00465·Dt2), with respect to a oxygen-flow-rate FhS(Nm3/hr) per hole of the Laval nozzle determined from the oxygen-flow-rate FS(Nm3/hr) in a high carbon region in a peak of decarburization and a throat diameter Dt(mm). An exit diameter De of the Laval nozzle satisfies the following formula with respect to the back pressure of the nozzle Po(kPa), an ambient pressure Pe(kPa), and the throat diameter Dt(mm): De2≦0.23×Dt2/{(Pe/Po)5/7×[1−(Pe/Po)2/7]1/2}.

Abstract: A method for blowing oxygen in a converter uses a top-blown lance having a Laval nozzle installed on its tip. The Laval nozzle has a back pressure of the nozzle Po(kPa) satisfying a formula, Po=FhS/(0.00465·Dt2), with respect to a oxygen-flow-rate FhS(Nm3/hr) per hole of the Laval nozzle determined from the oxygen-flow-rate FS(Nm3/hr) in a high carbon region in a peak of decarburization and a throat diameter Dt(mm). An exit diameter De of the Laval nozzle satisfies the following formula with respect to the back pressure of the nozzle Po(kPa), an ambient pressure Pe(kPa), and the throat diameter Dt(mm).