FIELD: metallurgy. SUBSTANCE: the claimed device has cluster unit accommodating porous plug. Porous plug consists of coaxial pressed parts whose external part is of truncated cone shape. parts are enclosed with conical shell having flange on the side of large base of porous plug. Said flange has hole for supply of inert gas formed between flange and porous plug is hollow. Porosity of porous plug is formed by channels. Shell with porous plug is attached to cluster unit by means of refractory cementing material. Internal part of porous plug is made in form of body of revolution or truncated polyhedral pyramid. Internal surface of external part of porous plug is of shape adequate to shape of internal part. Cross-sections of channels of porous plug are made in form of circle, or polygon, or segment and located over plane of contact of internal and external parts of porous plug. Hollow between flange and porous plug presents recess made on lower base of porous plug and/or on flange internal wall. In this case, diameter D1 of recess on lower base of porous plug is determined by relation D1=(1.01-1.50)D2, where D2 is diameter of lower base of internal part of porous plug or of circumference in which polyhedron of lower base of truncated polyhedral pyramid is inscribed. Flange on the side of porous plug is made with circular recess forming end face wall for joining the shell to form sealed full-strength seam. EFFECT: increased service life of tuyere, improved stability of inert gas flow at outlet of porous plug and reliability and safety in operation. 14 cl, 7 dwg
