A tuyere (or tuyère) is a nozzle that injects high-temperature blast air, often enriched with oxygen and pulverized coal, into a blast furnace.
Located at the upper boundary of the hearth, it forms the raceway, the furnace's main reaction zone. Because it is exposed to extreme heat, the tuyere is usually made from high-purity, hollow-cast copper and requires intensive internal water cooling to maintain its structural integrity.