Water-cooled blowing lance for blowing oxygen onto a molten metal

摘要

A water-cooled lance for blowing oxygen or oxygen containing gas onto a metal melt, for example an iron melt, for afterburning reaction gases from the melt and transfering the heat of afterburning back to the melt comprises a center tube forming a gas supply duct surrounded by further tubes for cooling water. The center tube leads to a head having a plurality of oxygen-blowing nozzles. Each of the nozzles has a plurality of oxygen outlet openings. The outlet openings have their centers lying on two concentric circles and are arranged so that each opening produces an individual gas stream. The axes of the outlet openings are inclined to the longitudinal axis of the lance at angles such that, in a plane perpendicular to the longitudinal axis of the lance and at a distance Lh from the head, the gas streams extend over an annular area in the plane having an inside diameter Di and and outside diameter Da. Lh, Di and Da have the following relationships: Di:Lh is the range of from 0.15 to 0.6; and, Da:Lh is the range of from 0.6 to 1.2.