Abstract: A stopper (1) is provided that includes ridges (12) in contact with the slag in a tundish (60). Each ridge (12) has a radial extension (21) that is less than half a radius (20) of the stopper (1) measured at the ridge (12). The ridges (12) rise and drop around the stopper (1). The ridges (12) decrease the creation of vortices by the stopper (1) and increase thus its lifetime.

Abstract: A stopper (1) is provided that includes ridges (12) in contact with the slag in a tundish (60). Each ridge (12) has a radial extension (21) that is less than half a radius (20) of the stopper (1) measured at the ridge (12). The ridges (12) decrease the creation of vortices by the stopper (1) and increase thus its lifetime. The ridges (12) are disposed in quincunx along the lateral wall (10).

Abstract: A submerged nozzle for casting molten metal into a mould, is provided that includes an erosion resistant sleeve (2) made of a material resistant to erosion provided over a tubular portion and extending along a longitudinal axis (Z). The erosion resistant sleeve includes at least one annular protrusion (2p), extending radially outwards beyond a recessed portion (2r) of the erosion resistant sleeve over the whole circumference of the erosion resistant sleeve (2), the at least one annular protrusion (2p) follows a periodic wavy trajectory oscillating between one or more tip-points situated closest to the first end and a corresponding number of one or more valley-points situated closest to the second end, the periodic wavy trajectory being defined by an amplitude (A) greater than 5 mm and a periodicity (P) comprised between 1 and 20 tip to valley to tip periods per 2? rad.

Abstract: A submerged nozzle for casting molten metal into a mould, is provided that includes an erosion resistant sleeve (2) made of a material resistant to erosion provided over a tubular portion and extending along a longitudinal axis (Z). The erosion resistant sleeve includes at least one annular protrusion (2p), extending radially outwards beyond a recessed portion (2r) of the erosion resistant sleeve over the whole circumference of the erosion resistant sleeve (2), the at least one annular protrusion (2p) follows a periodic wavy trajectory oscillating between one or more tip-points situated closest to the first end and a corresponding number of one or more valley-points situated closest to the second end, the periodic wavy trajectory being defined by an amplitude (A) greater than 5 mm and a periodicity (P) comprised between 1 and 20 tip to valley to tip periods per 2? rad.