Accretion controlling tuyere

摘要

A tuyere for refining molten metals or melting metal scrap or oxides charged into a vessel. The tuyere comprises three concentric pipes of copper or stainless steel encased in refractory. An annular stream of natural gas surrounds an annular stream of oxygen which in turn surrounds a core stream of natural gas. All three streams are expanded as they flow through the tuyere and as a result an accretion forms at the tip of the tuyere. The accretion protects the tuyere and the gas streams are controlled so that the accretion is maintained at a desired size which neither blocks the tuyere, nor permits burnback of the pipes.