APPARATUS FOR PROTECTING METAL STREAM BY MEANS OF GAS Russian patent published in 2004 - IPC

FIELD: metallurgy, possibly metal casting in continuous casting machines. SUBSTANCE: apparatus includes cylindrical housing having duct along its symmetry axis. At side of said duct there is annular groove normal relative to duct axis and forming upper and lower protrusions. Upper protrusion is cylindrical one. Lower protrusion is cylindrical in its upper part and it is cone in its lower part and inclined by angle 15 - 45 degrees relative to horizon. Relation of diameters of annular groove, cylindrical part of lower protrusion and upper annular protrusion is in range (1.05 - 1.07) : (1.01 - 1.05) : 1. Such relation determines gap value between annular protrusions and shell of casting nozzle of ladle. Gas fed into annular groove of apparatus leaves it through gaps without turbulence formation. Value of gap is selected in such a way that it prevents air suction into apparatus due to formation of solid gaseous curtain around metal stream. EFFECT: enhanced quality of ingot surface, limited generation of nitrogen in metal. 4 dwg, 1 tbl, 1 ex