Abstract: A stopper for continuous casting that is intended to prevent adhesion of inclusions to the vicinity of a fitting part of a stopper, and to prevent a nose region of the stopper from cracking or peeling off due to insufficient strength. The stopper for continuous casting includes a gas flow cavity in a vertically-extending central part thereof. In at least part of a vertical section of a nose periphery region of the stopper, a porous refractory material having a gas permeability is arranged on the side of an outer peripheral surface of the nose periphery region. A refractory material having higher strength than that of the porous refractory material is arranged on the side of an inner peripheral surface of the nose periphery region.

Abstract: The precision of grasping or controlling backpressure around a gas discharge portion in a stopper for continuous casting can be improved with a stopper for continuous casting which includes a cavity for conveying gas in a vertical direction center of the stopper, one or a plurality of gas discharge holes passing through from the cavity to the outside in a distal center or a side surface of a reduced-diameter region including a fitted portion to a lower nozzle, and a pressure control component in a part of an area above the gas discharge hole within the cavity.

Abstract: Provided is a nozzle or a stopper having a gas blowing function, which is capable of preventing irregular breaking to be triggered by a gas outlet or a gas passage path communicated with the gas outlet, or, even in the event of breaking, preventing expansion of the breaking, and a combination of the nozzle and the stopper. The nozzle comprises: a fitting engagement region refractory material layer composed of a fitting engagement region refractory material; a nozzle body composed of a different refractory material from the fitting engagement region refractory material (main body refractory material); and a gas outlet provided in at least one boundary area between the fitting engagement region refractory material layer and the main body refractory material in a surface of the nozzle contactable with molten steel.

Abstract: A tundish upper nozzle structure and a continuous casting method make it possible to cause inclusions to float within a tundish. A flange-shaped member having an outside dimension greater than that of an upper end of a tundish upper nozzle is provided along a part or the entirety of the circumference of the upper end of the tundish upper nozzle, and one or more gas discharge holes are provided in one or more of the following surfaces: a lower surface, an outer peripheral surface and a top surface of the flange-shaped member, and a region of an outer peripheral surface of the tundish upper nozzle below the flange-shaped member. A length in the tundish upper nozzle structure is adjusted to cause almost all gas to float upwardly, or to adjust the flow rate of gas flowing downwardly toward the inner bore of the tundish upper nozzle, and the flow rate of gas floating upwardly.

Abstract: Provided is a nozzle or a stopper having a gas blowing function, which is capable of preventing irregular breaking to be triggered by a gas outlet or a gas passage path communicated with the gas outlet, or, even in the event of breaking, preventing expansion of the breaking, and a combination of the nozzle and the stopper. The nozzle comprises: a fitting engagement region refractory material layer composed of a fitting engagement region refractory material; a nozzle body composed of a different refractory material from the fitting engagement region refractory material (main body refractory material); and a gas outlet provided in at least one boundary area between the fitting engagement region refractory material layer and the main body refractory material in a surface of the nozzle contactable with molten steel.

Abstract: The precision of grasping or controlling backpressure around a gas discharge portion in a stopper for continuous casting can be improved with a stopper for continuous casting which includes a cavity for conveying gas in a vertical direction center of the stopper, one or a plurality of gas discharge holes passing through from the cavity to the outside in a distal center or a side surface of a reduced-diameter region including a fitted portion to a lower nozzle, and a pressure control component in a part of an area above the gas discharge hole within the cavity.

Abstract: Second ground plane (18), substantially rectangular in shape, is connected to first ground plane (17) mounted with a data processing circuit, and radio communication circuit (12) makes radio communications at communication wavelength ?. A portion of second ground plane (18) from ground connecting means (14) to ground connecting means (33) along continuous edges of second ground plane (18) acts as an antenna. However, since the longest distance a between a plurality of ground connecting means (14, 33) along the continuous edges of second ground plane (18) satisfies “a<?/2?” (where ? is a coefficient equal to or larger than “1”), its resonant frequency is sufficiently higher than the communication frequency of the radio communication circuit.

Abstract: Second ground plane (18), substantially rectangular in shape, is connected to first ground plane (17) mounted with a data processing circuit, and radio communication circuit (12) makes radio communications at communication wavelength &lgr;. A portion of second ground plane (18) from ground connecting means (14) to ground connecting means (33) along continuous edges of second ground plane (18) acts as an antenna. However, since the longest distance a between a plurality of ground connecting means (14, 33) along the continuous edges of second ground plane (18) satisfies “a<&lgr;/2&agr;” (where &agr; is a coefficient equal to or larger than “1”), its resonant frequency is sufficiently higher than the communication frequency of the radio communication circuit.