The invention relates to a ceramic refractory stopper (a stopper device) for controlling a flow of molten metal at an outlet opening of a metallurgical vessel, such as a tundish.

The invention concerns a stopper rod and a method to provide a uniform gas curtain around a stopper rod.

A ventilating stopper rod has a temperature measurement function and is used for continuous casting. The stopper rod has a rod body, a rod head, a temperature measurement unit, a connecting pipe and exhaust passages; the rod body is a hollow structure; the upper end of the rod body is connected with the connecting pipe; the lower end of the rod body is connected with the rod head; the temperature measurement unit is used for measuring the temperature of the molten steel; the open end of the temperature measurement unit is connected with the rod head and communicates with the inner cavity of the rod body; the closed end of the temperature measurement unit extends out from the lower end of the rod head and is exposed from the rod head.

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.

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.

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.

A ceramic refractory stopper, shaped as a rod with a total axial length LS, comprising a) a stopper body (12) of an axial length LB, a first end section (12U) of which being equipped with means to fasten the stopper body (12) to a raise and lowering device, and a second end section (12L) of which being followed by b) a dome-like stopper head (14) of an axial length LH, wherein c) the stopper body (12) features at least one outer planar surface section (P1, P2, P3), which extends along at least 50% of the axial length LB of the stopper body (12).

A method of controlling an electromagnetic stirrer arranged around a submerged entry nozzle (SEN) of a tundish provided with a stopper rod to control throughput of the tundish, the SEN being configured to provide tapping of molten metal from the tundish and the electromagnetic stirrer being configured to generate a rotating magnetic field in the SEN, wherein the method includes controlling the electromagnetic stirrer to operate only when a gas flow rate through the stopper rod is in a first range of 1.5 NL/min to 20 NL/min.

A method of controlling an electromagnetic stirrer arranged around a submerged entry nozzle (SEN) of a tundish provided with a stopper rod to control throughput of the tundish, the SEN being configured to provide tapping of molten metal from the tundish and the electromagnetic stirrer being configured to generate a rotating magnetic field in the SEN, wherein the method includes controlling the electromagnetic stirrer to operate only when a gas flow rate through the stopper rod is in a first range of 1.5 NL/min to 20 NL/min.

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.