Blast furnace tuyere, or lance nozzle for oxygen converters - where protective coating of iron or steel increases working life

摘要

The tuyere is made of copper or other metals and is cooled by a liq. flowing through the interior of the tuyere. Before use in the blast furnace, the tuyere is dipped into molten crude iron or steel so a protective layer (a) of iron or steel is formed on the immersed part of the cooled tuyere. Instead of a tuyere, the invention can also be applied to injection nozzles or lances, used to inject O2 into oxygen steel making converters, where the nozzle is cooled by a liq. while being immersed in molten iron or steel to form a solidified protective layer (a). The nozzle in which the coolant flows is pref. made of material with a higher coefft. of thermal expansion than layer (a) which is exposed to combustion gases in the converter, i.e. above the melt. Layer (a) resists attack by molten metal, slag or gases better than Cu or other metals, so the working life of a tuyere or an outlet nozzle on an O2 lance is increased.