Tuyere

a device for supplying an air blast in metallurgical furnaces or for blowing oxygen into metal baths in steelmaking and the smelting of nonferrous metals. In blast furnaces a tuyere is a nozzle with a water-cooled jacket, and in cupolas and water-cooled blast furnaces it is a slit-shaped opening in the wall of the unit. In converters, open-hearth furnaces, and two-bath steel-making furnaces such a device is called a lance; it is a pipe for supplying oxygen that has a tip of special construction and a water-cooled jacket. A mechanism is provided for raising, lowering, and replacing the tuyere. Besides oxygen, powdered materials can be supplied through tuyeres and lances (for example, in the basic oxygen process).