An annular weir is fixed at a bottom of a tundish and just under a long nozzle of a ladle in a continuous casting apparatus. The annular weir includes a cavity which has a substantially circular shaped transverse section. The cavity includes: an upper side opening configured to receive a stream of molten metal from an upper side through the long nozzle; an inner protrusion which is annular in shape and which extends toward an inner side from an upper end of an inner wall of the cavity; a first space on an inner side of the inner protrusion; and a second space which communicates with the first space 13 a and which is on a lower side of the first space.
1. An annular weir fixed at a bottom of a tundish and under a long nozzle of a ladle in a continuous casting apparatus, the annular weir comprising a cavity which has a substantially circular shaped transverse section, the cavity including:
an upper side opening configured to receive a stream of molten metal from an upper side through said long nozzle;
an inner protrusion which is annular in shape, the inner protrusion extending toward an inner side from an upper end of an inner wall of said cavity;
a first space on an inner side of said inner protrusion; and
a second space which communicates with said first space, the second space being on a lower side of said first space, wherein:
an inside diameter of said first space is within a range of 4 times to 5 times a diameter of a discharge hole of said long nozzle, and an inside diameter of said second space is within a range of 1.2 times to 1.5 times the inside diameter of said first space; and
a height of said annular weir is within a range of ⅙ to ¼ of a height of a surface of a bath in the tundish during operation.
2. The annular weir as claimed in claim 1 , wherein the cavity is a bore that bores in an upper and lower direction.
3. An annular weir fixed at a bottom of a tundish and under a long nozzle of a ladle in a continuous casting apparatus, the annular weir comprising a cavity which has a substantially circular shaped transverse section, the cavity including:
an upper side opening configured to receive a stream of molten metal from an upper side through said long nozzle;
an inner protrusion which is annular in shape, the inner protrusion extending toward an inner side from an inner wall of said cavity;
a third space on an upper side of said inner protrusion;
a first space which communicates with said third space, the first space being on a lower side of said third space and on an inner side of said inner protrusion; and
a second space which communicates with said first space, the second space being on a lower side of said first space, wherein:
an inside diameter of said first space is within a range of 4 times to 5 times a diameter of a discharge hole of said long nozzle, and an inside diameter of said second space is within a range of 1.2 times to 1.5 times the inside diameter of said first space; and
a height of said annular weir is within a range of ⅙ to ¼ of a height of a surface of a bath in the tundish during operation.
4. The annular weir as claimed in claim 3 , wherein an inside diameter of said third space is within a range of 1 time to 1.1 times the inside diameter of said second space.
5. The annular weir as claimed in claim 3 , wherein the cavity is a bore that bores in an upper and lower direction.