TUYERE FOR BOTTOM BLOWING OF METAL, METHOD FOR MAKING TUYERE AND APPARATUS FOR ITS EMBODIMENT Russian patent published in 2001 - IPC

FIELD: metallurgy, namely, tuyeres for bottom blowing of metals. SUBSTANCE: tuyere includes solid and hollow truncated cones made at double-side pressing in the form of separate parts being inner and outer pieces of blowing unit enclosed by metallic envelope with gas-passing pipe. Blowing units are made of carbon-containing refractory material with bulk density no less than 1.7 g/cu.cm, apparent density no less than 3 g/cu.cm and open porosity no more than 8% after double-side pressing at specific pressure no less than 120 N/sq. mm. Carbon content of said material -(3-15)%. Before assembling, joined cone surfaces of blowing units are lapped and embedded members are applied onto them for forming gas supply slits between them. Assembled unit is subjected to heat treatment at temperature 150-1400 C. Mean portion of punch for pressing hollow truncated cone units and for knocking out ready article is in the form of truncated cone defining inner surface of units. Upper part of punch is in the form of cylindrical pressing head engaged with upper pressing ram. Lower part of punch is in the form of elongated cylindrical stem provided with sleeve movable relative to stem and having lower pressing head. Lower pressing ram engages with movable sleeve and it has opening for punch. Adjusting washers may be placed onto upper and lower pressing heads. Tuyere provides stable flow of inert gas at its outlet. EFFECT: increased useful life period, lowered refractory material consumption, enhanced safety and reliability, lowered cost price of tuyere. 7 cl, 7 dwg, 1 tbl