摘要:
A unitized nozzle and top plate assembly for use in a slide gate valve is disclosed which comprises a nozzle having porous, gas permeable walls, a top plate having an opening through its thickness for regulating a flow of molten metal, such as steel, and a recess circumscribing the opening for receiving and securing the discharge end of the nozzle to the top plate. The depth of the recess is at least 50%, and preferably 70-80% of the thickness of the top plate in order to minimize the contact between molten metal and the surface of the top plate opening, which in turn reduces the amount of flow-obstructing alumina deposits which accumulate in this area of the slide gate valve. To prevent leaks from occurring in the system supplying pressurized argon through the porous nozzle walls, the gas coupling that is normally welded directly to the steel can surrounding the nozzle is instead mounted on the end of a steel pipe connected to the can. The thermal resistance of the steel pipe substantially reduces the temperature that the coupling is exposed to. The invention also encompasses a method for facilitating the assembly and maintenance of the slide gate valve by the use of the unitized nozzle and top plate in lieu of the in situ mounting of such a nozzle on a top plate already installed in such a valve.
摘要:
A tundish assembly, including an element, for preventing or limiting steel reoxidization in the continuous casting of molten steel, is used in combination with a refractory nozzle. The element has an orifice engaging the outer surface of the nozzle, a main surface surrounding the main orifice and having a lowest level lower than the top outer edge of the nozzle inlet portion, and a periphery having an upper face surrounding the man surface of the element. The upper face of the periphery of the element is higher than the main surface of the element and is higher than the surface of the bottom well of the tundish. The main surface of the element is arranged so as to contact molten steel when the tundish is in use.
摘要:
A permeable, resin-bonded composition is described, which finds utility as a porous element in a gas-injection nozzle. The permeable composition is notably useful in a canless, resin-bonded, gas-injection nozzle, characterized by an impermeable, resin-bonded composition replaces the metal can. Advantageously, the resin-bonded compositions include an oxygen getter for scrubbing oxygen before the oxygen can reach the molten steel. A method of manufacturing the nozzle is described and includes copressing a standard, resin-bonded composition around the permeable, resin-bonded composition. The pressed piece may be cured at temperatures below about 800° C.
摘要:
A refractory element is configured to prevent or limit steel reoxidation in a steel casting process. The refractory element contains a base surrounded by a periphery in a specified geometrical arrangement. The refractory element is constituted of a base surrounded by a periphery in a specified geometrical arrangement.
摘要:
A tundish assembly, including an element, for preventing or limiting steel reoxidization in the continuous casting of molten steel, is used in combination with a refractory nozzle. The element has an orifice engaging the outer surface of the nozzle, a main surface surrounding the main orifice and having a lowest level lower than the top outer edge of the nozzle inlet portion, and a periphery having an upper face surrounding the main surface of the element. The upper face of the periphery of the element is higher than the main surface of the element and is higher than the surface of the bottom well of the tundish. The main surface of the element is arranged so as to contact molten steel in a tundish.
摘要:
A tundish assembly, including an element, for preventing or limiting steel reoxidization in the continuous casting of molten steel, is used in combination with a refractory nozzle. The element has an orifice engaging the outer surface of the nozzle, a main surface surrounding the main orifice and having a lowest level lower than the top outer edge of the nozzle inlet portion, and a periphery having an upper face surrounding the man surface of the element. The upper face of the periphery of the element is higher than the main surface of the element and is higher than the surface of the bottom well of the tundish. The main surface of the element is arranged so as to contact molten steel when the tundish is in use.
摘要:
A tundish assembly, including an element, for preventing or limiting steel reoxidization in the continuous casting of molten steel, is used in combination with a refractory nozzle. The element has an orifice engaging the outer surface of the nozzle, a main surface surrounding the main orifice and having a lowest level lower than the top outer edge of the nozzle inlet portion, and a periphery having an upper face surrounding the man surface of the element. The upper face of the periphery of the element is higher than the main surface of the element and is higher than the surface of the bottom well of the tundish. The main orifice of the element is off-center with respect to the main surface and the upper face of the periphery may have various heights. The main surface of the element is arranged so as to contact molten steel in a tundish.
摘要:
A refractory nozzle assembly is provided that effectively prevents the accumulation of alumina deposits around its upper edge where it receives a stopper rod. The nozzle assembly includes a refractory nozzle body having an upper and a lower portion. A bore extends through both the upper and lower portions that has a receiving and a discharge end for receiving and discharging molten metal. An inert gas distributor circumscribes the upper portion of the nozzle body. A sleeve of gas-obstructing refractory material covers the walls of the bore, and defines a seat portion at an upper portion of the bore. A metal sheath substantially surrounds the outer surface of the upper portion. Pressurized inert gas conducted to the upper, gas permeable portion of the nozzle body by the gas-distributing assembly is guided by the gas-obstructing sleeve and the metal sheath so that it flows predominantly through the top edge of the upper portion. The resulting inert gas flow shields the seat portion of the bore from ambient oxygen, thereby preventing the accumulation of alumina deposits on the seat portion that can interfere with the ability of the stopper rod to control the flow of molten metal.