Abstract: A sliding nozzle device automatically performs a series of operations of loading and unloading pressure between plates and opening and closing a slide frame; maintaining the pressure without additional operations; and operates at full stroke during molten steel flow control. An auxiliary plate-exchanging mechanism includes slide axes moving in the same direction as a hydraulic cylinder operates, and an arm having a proximal end placed around the slide axis. The plate-exchanging mechanism is fixed on an upside frame. A first engagement pin mounted on the proximal end of the arm is inserted in a first engagement groove in a first engagement member engaging with the slide axis, and second engagement pins mounted on bearings are inserted in second engagement grooves in the slide axes. With movement of the slide axes the engagement pins respectively move in the engagement grooves, thereby rotating the slide axes and the arm.

Abstract: A tundish nozzle is used in a device for exchanging tundish nozzles juxtaposed at a bottom of a tundish. The device includes a pair of first arms pressing and supporting a first lower nozzle located at an undersurface of a first upper nozzle, the first upper nozzle being placed at the bottom of the tundish. The device includes a pair of second arms pressing and supporting a second lower nozzle located at an undersurface of a second upper nozzle, the second upper nozzle being placed at the bottom of the tundish and next to the first upper nozzle. The pair of first arms and the pair of second arms are adjoined to each other, the pairs at least partly overlapping. The tundish nozzle includes a zirconia based nozzle inserted into an alumina based refractory, and is one of the first and second lower and upper nozzles.

Abstract: A device for exchanging tundish nozzles juxtaposed at a bottom of a tundish includes a pair of first arms and a pair of second arms. The pair of first arms presses and supports a first lower nozzle. The first lower nozzle is located at an undersurface of a first upper nozzle. The first upper nozzle us placed at the bottom of the tundish. The pair of second arms presses and supports a second lower nozzle. The second lower nozzle is located at an undersurface of a second upper nozzle. The second upper nozzle is places at the bottom of the tundish and next to the first upper nozzle. The pair of first arms and the pair of second arms are adjoined to each other, and the pairs at least partly overlap each other.

Abstract: A tundish nozzle exchanging device and a tundish nozzle for use in the device, reducing a distance between holes of the tundish nozzles, juxtaposed at a bottom of a tundish, compared to the conventional model.

Abstract: A sliding nozzle device automatically performs a series of operations of loading and unloading pressure between plates and opening and closing a slide frame; maintaining the pressure without additional operations; and operates at full stroke during molten steel flow control. An auxiliary plate-exchanging mechanism includes slide axes moving in the same direction as a hydraulic cylinder operates, and an arm having a proximal end placed around the slide axis. The plate-exchanging mechanism is fixed on an upside frame. A first engagement pin mounted on the proximal end of the arm is inserted in a first engagement groove in a first engagement member engaging with the slide axis, and second engagement pins mounted on bearings are inserted in second engagement grooves in the slide axes. With movement of the slide axes the engagement pins respectively move in the engagement grooves, thereby rotating the slide axes and the arm.

Abstract: A method of controlling a sliding nozzle device 10 and a plate 13 used therefor, even if operational conditions are changed, automatically optimizing sliding conditions of the device 10, increasing a life of the plate 13, and reducing a corrosion rate and a stroke length of the plate 13. When the device 10 is controlled, if an average cumulative sliding rate of the plate 13 is outside a control range, a sliding rate of the plate 13 is changed within a preset range, thereby automatically optimizing the sliding conditions of the device 10 even with an operational condition change. Also, 3% to 20% of average sliding rate can reduce the corrosion rate of the plate 13 and drastically increase the life of the plate 13.

Abstract: A slide gate includes a frame fixed to a bottom of a molten-steel vessel, a guide frame attached to a bottom of the frame which can opened and closed, a plurality of refractory plates, a pair of surface-pressure bars and a cylinder. The plurality of refractory plates are disposed in a space surrounded by the frame and the guide frame with one of the refractory plates being slidable to control an amount of opening of a nozzle gate. The cylinder drives the slidable refractory plate to move a slide block with a protrusion. The protrusion moves a connecting member of the pair of surface-pressure bars so that the guide frame is connected with the frame and the slidable refractory plate is pressed to an immediate upper refractory plate by coil spring.