HOT METAL TAP HOLE FOR BLAST FURNACE AND TAP HOLE DRILL Russian patent published in 2002 - IPC

FIELD: metallurgy. SUBSTANCE: tap hole device has discharge channel of variable-profile along the entire length thereof, namely, its inlet part from hearth is formed cylindrical, its middle part is made in the form of conical diffuser and its outlet part is formed cylindrical and has diameter equal to that of diffuser larger base. Tap hole drill for forming channel of said profile has set of cutting tools arranged in succession lengthwise of carrier rod along its generatrices. Discharge of cast iron and slag through variable-profile channel allows separation of cast iron and slag to be improved, time of discharge of cast iron and slag from furnace to be reduced and, as a result, number of discharges per day to be increased. Tap hole of such construction eliminates growth of transportation grooves, including growing during discharge of cast iron and slag having increased viscosity and temperature. EFFECT: increased efficiency due to reduced metal losses by slagging. 3 cl, 3 dwg, 1 tbl