Accretion Controlling Tuyere

摘要

A tuyere (10) for refining molten metals or melting metal scrap or oxides charged into a vessel. The tuyere (10) comprises three concentric pipes (12,32,40) of copper or stainless steel encased in refractory (44). 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 (10) and as a result an accretion (50) forms at the tip of the tuyere. The accretion protects the tuyere (10) and the gas streams are controlled so that the accretion (50) is maintained at a desired size which neither blocks the tuyere (10), nor permits burnback of the pipes (12,32,40).