Pulverized Coal Lance (Coal Injection Lance)

In the blast furnace pulverized coal injection system of steel plants, the pulverized coal lance (also known as the coal injection lance) is the core execution component that ultimately delivers pulverized coal to the blast furnace tuyere and enables efficient combustion. It directly determines the injection velocity, atomization effect, combustion efficiency of the pulverized coal, and its impact on the blast furnace conditions. It serves as the "last mile" critical equipment connecting the coal injection system with blast furnace smelting. 

I. Core Functions and Roles of the Pulverized Coal Lance The primary task of the pulverized coal lance is to inject the uniformly distributed pulverized coal-airflow mixture from the distributor into the high-temperature raceway of the blast furnace tuyere at a specific velocity, angle, and distribution pattern. This ensures rapid and complete combustion of the pulverized coal, providing heat and reductants (replacing part of the coke) for the blast furnace. Its specific functions include:

 1. Precise Delivery: Steadily delivering pulverized coal to the combustion zone (center of the raceway) of the blast furnace tuyere, avoiding premature or delayed combustion.

 2. Efficient Atomization: Utilizing the special structure of the lance nozzle to disperse the pulverized coal-airflow mixture into fine particles, increasing the contact area with high-temperature gas and enhancing combustion efficiency (target combustion rate ≥95%).

 3. Flashback Protection: Working in conjunction with the front-end ball valve (check valve) to prevent high-temperature gas from the blast furnace (temperature 1500-2000°C, pressure 0.3-0.5MPa) from flowing back into the coal injection system, avoiding safety incidents.

 4. Adaptation to Furnace Conditions: Adjusting the insertion depth and injection angle of the lance to meet the requirements of different smelting stages (such as furnace startup, normal operation, and blowing interruption) of the blast furnace.