Abstract: An optical unit of plastic provided with a surface for incident light and a surface for outgoing light, wherein the surface for incident light is designed to face a light source and the surface for outgoing light is designed to face an element for receiving light so as to optically connect the light source and the element for receiving light and wherein the optical unit is so shaped that light that comes from the light source and is incident on the surface for incident light forms a first image of the light source within the optical unit and a second image of the light source after having gone through the surface for outgoing light and the optical unit is provided with an attenuating portion for attenuating the quantity of light passing therethrough in the vicinity of the position where the first image is formed.

Abstract: In a gas wiping apparatus for blowing a gas on the front side and the back side of a strip, which exits from a hot-dip plating bath and travels upward, from wiping nozzles to adjust the amount of a plating deposit, the wiping nozzles are supported to be linearly movable beyond the width of the nozzles in the plate width direction of the strip.

Abstract: In a gas wiping apparatus which blows gas through a wiping nozzle onto front and rear surfaces of a steel plate going out from a molten metal coating pot and running upward and which thereby controls a deposit mass, the wiping nozzle is separated into upper and lower lips, blocking faces partially closing a gas supply channel are formed in the upper and lower lips at vertically different positions on the opposite sides from each other in a gas outlet width direction, and the upper and lower lips are provided in such a manner as to be movable in a width direction of the steel plate.

Abstract: A liquid wiping apparatus that can eliminate the increase in the thickness of membranous liquid and defects in the surface quality resulting from the attachment of splash onto the surface of a metallic strip and can improve the productivity in a manner of accelerating the line speed is provided. The liquid wiping apparatus includes blade wipers for contacting with a molten metal having been attached onto the metallic strip 1 to mechanically wipe the molten metal. In the liquid wiping apparatus, a pressure applying unit 7 of the static pressure pad type using gas is installed at the outlet side of the blade wiper 6 in the strip running direction, and phase-mixed flow of gas/liquid 15 is produced in membranous liquid running between the blade wiper 6 and the strip 1.

Abstract: In a gas wiping apparatus for blowing a gas on the front side and the back side of a strip, which exits from a hot-dip plating bath and travels upward, from wiping nozzles to adjust the amount of a plating deposit, the wiping nozzles are supported to be linearly movable beyond the width of the nozzles in the plate width direction of the strip.

Abstract: In a gas wiping apparatus which blows gas through a wiping nozzle onto front and rear surfaces of a steel plate going out from a molten metal coating pot and running upward and which thereby controls a deposit mass, the wiping nozzle is separated into upper and lower lips, blocking faces partially closing a gas supply channel are formed in the upper and lower lips at vertically different positions on the opposite sides from each other in a gas outlet width direction, and the upper and lower lips are provided in such a manner as to be movable in a width direction of the steel plate.

Abstract: A liquid wiping apparatus that can eliminate the increase in the thickness of membranous liquid and defects in the surface quality resulting from the attachment of splash onto the surface of a metallic strip and can improve the productivity in a manner of accelerating the line speed is provided. The liquid wiping apparatus includes blade wipers for contacting with a molten metal having been attached onto the metallic strip 1 to mechanically wipe the molten metal. In the liquid wiping apparatus, a pressure applying unit 7 of the static pressure pad type using gas is installed at the outlet side of the blade wiper 6 in the strip running direction, and phase-mixed flow of gas/liquid 15 is produced in membranous liquid running between the blade wiper 6 and the strip 1.

Abstract: The present invention provides a liquid wiping apparatus that can eliminate the increase in the thickness of membranous liquid and defects in the surface quality resulting from the attachment of splash onto the surface of a metallic strip and can improve the productivity in a manner of accelerating the line speed. The liquid wiping apparatus according to this invention includes blade wipers for contacting with a molten metal having been attached onto the metallic strip 1 to mechanically wipe the molten metal. In the liquid wiping apparatus, a pressure applying means 7 of the static pressure pad type using gas is installed at the outlet side of the blade wiper 6 in the strip running direction, and phase-mixed flow of gas/liquid 15 is produced in membranous liquid running between the blade wiper 6 and the strop 1.

Abstract: A method of producing reduced iron pellets including reducing raw material pellets to obtain reduced iron pellets, and rolling the reduced iron pellets at a temperature ranging between 800 and 1200° C. sufficiently such that the reduced iron pellets undergo sintering.

Abstract: A reduced iron discharger in a rotary hearth reducing furnace scoops up reduced iron on a rotary hearth from a front side with the use of an impeller enough long to cover the entire width of the rotary hearth, drops the reduced iron onto a vibrating conveyor mounted in the impeller, and discharges it from an outlet to the outside of the reducing furnace. The reduced iron discharger involves minimal structural waste, and gives a satisfactory yield.

Abstract: A pretreatment apparatus for raw materials for production of reduced iron pretreats the raw materials, comprising an iron material, such as iron ore, and other raw materials, such as coal and flux, by a dryer, classifiers, a roll press, and a vertical mill, and feeds the pretreated raw materials to a pelletizer via a feed bin. At least two fluidized mixers for mixing the classified raw materials, one of the fluidized mixers for storage and the other fluidized mixer for supply, are provided for batch treatment. The pretreatment apparatus can uniformize the crushed particle sizes of iron ore, coal, etc. different in hardness, stably supply homogeneously mixed raw materials, and simplify pelletization-side facilities.

Abstract: An apparatus for producing reduced iron, and a compact drying method for application to the apparatus are disclosed. The apparatus comprises a pelletizer or a briquetter for mixing and agglomerating coal as a reducing agent and iron ore as iron oxide to form compacts, a dryer for drying the compacts, a circular rotary hearth type reducing furnace for reducing the dried compacts in a high temperature atmosphere, a first heat exchanger for performing heat exchange between a hot off-gas discharged from the reducing furnace and combustion air to be supplied to the reducing furnace, and coolers for cooling the hot off-gas. A second heat exchanger for heating drying air is disposed on an exit side of the first heat exchanger. The drying air heated by the second heat exchanger is supplied to the dryer to dry the compacts with the drying air which is scant in moisture. Consequently, highly efficient, stable drying in the dryer can be performed, and high quality reduced iron can be produced stably.

Abstract: In the production of reduced iron by agglomerating a mixed powder of an iron material and a reducing agent to form compacts like briquettes or pellets, and reducing the compacts in a high temperature atmosphere, when the temperature of reduced compacts is 900° C. or higher, the oxide content in the reduced compacts is set at 11% or more, and the basicity of the reduced compacts is set at 0.5 or higher.

Abstract: An apparatus for producing reduced iron by agglomerating a mixed powder of an iron material and a reducing agent to form compacts like briquettes or pellets, and reducing the compacts in a high temperature atmosphere is disclosed. In the apparatus, a rotary hearth in an annular form is rotatably supported. Right and left furnace walls and a ceiling are provided to cover an area above the rotary hearth, thereby forming a space portion in a high temperature atmosphere. A compact supply portion, and a compact discharge portion are provided adjacently in the ceiling. Partitioning members are provided as partitions between the compact supply portion, the compact discharge portion, and the high temperature atmosphere space portion.

Abstract: An apparatus for producing reduced iron, and a compact drying method for application to the apparatus are disclosed. The apparatus comprises a pelletizer or a briquetter for mixing and agglomerating coal as a reducing agent and iron ore as iron oxide to form compacts, a dryer for drying the compacts, a circular rotary hearth type reducing furnace for reducing the dried compacts in a high temperature atmosphere, a first heat exchanger for performing heat exchange between a hot off-gas discharged from the reducing furnace and combustion air to be supplied to the reducing furnace, and coolers for cooling the hot off-gas. A second heat exchanger for heating drying air is disposed on an exit side of the first heat exchanger. The drying air heated by the second heat exchanger is supplied to the dryer to dry the compacts with the drying air scant in moisture. Consequently, highly efficient, stable drying in the dryer can be performed, and high quality reduced iron can be produced stably.

Abstract: An apparatus for producing reduced iron, and a compact drying method for application to the apparatus are disclosed. The apparatus comprises a pelletizer or a briquetter for mixing and agglomerating coal as a reducing agent and iron ore as iron oxide to form compacts, a dryer for drying the compacts, a circular rotary hearth type reducing furnace for reducing the dried compacts in a high temperature atmosphere, a first heat exchanger for performing heat exchange between a hot off-gas discharged from the reducing furnace and combustion air to be supplied to the reducing furnace, and coolers for cooling the hot off-gas. A second heat exchanger for heating drying air is disposed on an exit side of the first heat exchanger. The drying air heated by the second heat exchanger is supplied to the dryer to dry the compacts with the drying air scant in moisture. Consequently, highly efficient, stable drying in the dryer can be performed, and high quality reduced iron can be produced stably.

Abstract: A pretreatment apparatus for raw materials for production of reduced iron pretreats the raw materials, comprising an iron material, such as iron ore, and other raw materials, such as coal and flux, by a dryer, classifiers, a roll press, and a vertical mill, and feeds the pretreated raw materials to a pelletizer via a feed bin. At least two fluidized mixers for mixing the classified raw materials, one of the fluidized mixers for storage and the other fluidized mixer for supply, are provided for batch treatment. The pretreatment apparatus can uniformize the crushed particle sizes of iron ore, coal, etc.

Abstract: A reduced iron discharger in a rotary hearth reducing furnace scoops up reduced iron on a rotary hearth from a front side with the use of an impeller enough long to cover the entire width of the rotary hearth, drops the reduced iron onto a vibrating conveyor mounted in the impeller, and discharges it from an outlet to the outside of the reducing furnace. The reduced iron discharger involves minimal structural waste, and gives a satisfactory yield.

Abstract: Several methods and production facilities are provided in order to solve several problems encountered in conventional methods and facilities for producing reduced iron by reducing raw material pellets of a mixture of an iron oxide powder and a reducing material powder in a rotary bed-type reducing furnace and by melting the reduced iron in a sealed-type electro-blast furnace.

Abstract: A billet continuous casting machine comprises, and a billet continuous casting method uses, a jacket for cooling an outer wall of a quadrangular tubular mold with cooling water, electromagnetic brakes disposed outside the mold for decelerating the flow speed of poured molten metal in the mold, an X ray-based level sensor for detecting the level of molten metal in the mold, notched portions formed at the corners of a quadrangular lower part of the mold, spray nozzles for spraying a cooling liquid directly onto the notched portions, and elastically pushing means for imparting a pushing force corresponding to the static pressure of the molten metal to unnotched portions of the quadrangular lower part of the mold to push the unnotched portions inwardly of the mold, whereby molten metal is continuously poured into the cooled mold to solidify the molten metal so that a cast piece quadrangular in cross section is continuously produced.