A tuyere assembly is an essential component installed in the blast furnace hearth wall, responsible for injecting preheated air (hot blast) into the furnace to combust coke and generate the high temperatures required for iron ore reduction. It maintains precise airflow control and protects furnace structure from extreme heat. The assembly ensures efficient combustion and uniform temperature distribution within the furnace, directly impacting iron production quality and furnace longevity. Constructed from copper alloy (CuCrZr) with high thermal conductivity, stainless steel, and refractory lining, it withstands severe thermal and mechanical stresses. The assembly includes a water-cooled nozzle, a flange connection (DN200–DN300 per ISO 7005), and internal passages for cooling water. Key parameters include a nozzle diameter of 100–180 mm, cooling water flow rate of 15–30 m³/h, maximum operating temperature of 1200–1300 °C, hot blast pressure rating of 0.3–0.5 bar, overall length of 500–800 mm, cooling water pressure of 0.4–0.8 MPa, weight of 80–150 kg, cooling water temperature rise of 5–10 °C, and surface roughness of Ra 3.2–6.3 μm (ISO 1302). These values are reference ranges for typical industrial tuyere assemblies; actual specifications must be confirmed with the legal manufacturer for the specific blast furnace model and operating conditions. The assembly's design ensures efficient heat transfer and erosion resistance, contributing to stable furnace operation. Proper selection requires consideration of furnace size, hot blast temperature, pressure, and cooling water quality. Installation and maintenance must follow manufacturer guidelines to ensure safe and reliable performance. Verification of material grades, standards, and performance parameters is essential before procurement. The tuyere assembly is a critical component for ironmaking, and its failure can lead to furnace downtime and safety hazards. Regular inspection of cooling water flow, temperature rise, and surface condition is necessary to detect early signs of wear or blockage. The assembly's working principle involves the injection of hot blast air through the nozzle, where it reacts with coke to produce carbon monoxide and intense heat for iron ore reduction, while cooling water circulates to prevent thermal damage. This process is fundamental to blast furnace operation, and the tuyere assembly's performance directly affects iron quality and furnace campaign life.
Hot blast air is forced through the tuyere nozzle into the furnace, where it reacts with coke to produce carbon monoxide and intense heat for iron ore reduction. Simultaneously, cooling water circulates through the assembly's internal passages, absorbing heat and preventing thermal damage to the copper alloy and refractory components. The precise control of airflow and cooling water flow ensures efficient combustion and uniform temperature distribution within the furnace. The assembly's design allows for thermal expansion and maintains a seal against high-pressure gases. The cooling water pressure and flow rate are critical to maintain adequate heat transfer and prevent steam formation. The nozzle diameter and hot blast pressure determine the air velocity and penetration into the furnace bed, influencing combustion efficiency and raceway depth. The assembly must withstand thermal cycling and abrasive wear from coke and ore particles. Regular monitoring of cooling water temperature rise and pressure drop can indicate potential issues such as blockage or erosion. The working principle is based on the balance between heat input from combustion and heat removal by cooling water, ensuring the tuyere remains at a safe operating temperature.
