Lanhao Environmental Protection produces steel mill pulverized coal ball valves and lance check valves, which are core safety components of the blast furnace pulverized coal injection system. They are primarily used to control pulverized coal injection and prevent hot blast furnace gas from flowing backward.
Core Workflow
Automatically opens when the lance is inserted
When the pulverized coal lance is inserted into the blast furnace tuyere, the front end of the lance mechanically pushes the ball (metal ball), overcoming spring pressure to disengage it from the valve seat sealing surface, forming a pulverized coal delivery channel.

Maintains flow during injection
The pulverized coal airflow continuously pushes the ball open using delivery pressure, ensuring that the pulverized coal passes through the valve body into the blast furnace tuyere area. At this point, the ball remains suspended under the action of the airflow, keeping the channel clear.

Automatically locks when the lance is withdrawn
The moment the lance is withdrawn, the ball rapidly resets under the action of three forces:
Internal blast furnace pressure squeezes the ball upward;
Spring pressure pushes the ball downward;
Gravity assists in its descent.
These three forces work together to ensure the ball tightly adheres to the valve seat, achieving millisecond-level sealing and preventing the leakage of hot gas exceeding 1400°C from the furnace.