Gas blowing nozzle, and production and usage thereof

Claim 1

A nozzle for refining molten metal, comprising a non-porous refractory structure positionable at a bottom or a wall of a converter; a plurality of passageways for transmitting gas formed in said refractory structure, said passageways being of metal pipes; an upper metal plate and a lower metal plate defining therebetween a gas storage area communicating with said passageways at the bottom of said refractory structure, said upper plate having a plurality of holes corresponding to said passageways; a metal cover encircling said refractory structure and said storage area; and lead pipe connectable to said lower metal plate, said metal pipes being connected to said holes in said upper metal plate; wherein said passageways have a a diameter of from 0.1 to 5 mm, and have a space therebetween of from 3 mm to 150 mm; wherein said plurality of passageways have walls of metal with thicknesses of from 0.1 to 10 mm; wherein said metal cover has a thickness of from 0.1 to 5 mm; wherein said gas storage area has a space between said upper metal plate and said lower metal plate of from 2 mm to 50 mm distance; and wherein said said plurality of passageways comprises a plurality of outside passageways and a plurality of inside passageways, said outside passageways being disposed on the outside of said inside passageways, said outside passageways having a diameter smaller than the diameter of said inside passageways.