Tuyere for injecting refining gas into molten metal - using defined tuyere length in melt to reduce wear of converter lining

摘要

Tuyere for injecting refining gas into a metal bath in a vessel provided with a refractory lining, the tuyere possessing an outer tube (I) passing through the lining on the wall of the base of the vessel and contg. at least one inner tube (II) carrying the refining gas, whereas the annular space between the tubes carries a medium protecting the tuyere against wear. The novelty is that the free part of tube (I) projects into the bath by a length "L" in metres from the surface of the lining and where D is the bore of tube (I) in metres; P is the absolute pressure in atmos. and T the temp. in degree K, of the refining gas(es) in the tuyere head. The protective medium is pref. NH3, water, steam, gas- or liq. - hydrocarbons, or their mixt. Tuyere is used e.g. for refining steel in a converter, where the projecting length of the tuyere prevents excessive erosion of the lining round the tuyere due to currents of gas travelling backwards round the outer tube to the lining.