The injection tank (also known as the pulverized coal injection tank) in the steel mill injection system is the core storage and transportation equipment for blast furnace coal injection technology. It is responsible for the temporary storage, fluidization, and pneumatic conveying of pulverized coal. Its structure and working principle are as follows:
Core Functions and Structural Design
Pulverized Coal Storage and Transportation Hub
As a sealed pressure vessel, the injection tank receives pulverized coal from the coal bunker through the feed valve;
The tank consists of an elliptical head, a straight cylindrical section, and a conical lower head. The inner wall is overlay welded with wear-resistant alloy or coated with ceramic to resist erosion by pulverized coal;

Volume ranges from 1 to 50 cubic meters (mainstream 25 cubic meters), design pressure ≥1.0 MPa, temperature resistance 95°C (instantaneous 1200°C).
Fluidization and Conveying Control
Component? ?Function
Conical Fluidization Plate? Compressed air is injected through inclined nozzles (not perpendicular to the tank wall) to avoid direct airflow erosion of the tank;
Fluidization Nozzles? Multiple sets of nozzles are installed in the conical section to agitate the pulverized coal into a fluidized state, reducing conveying resistance;
Mixer? Connected to a boiling-type mixer at the bottom, secondary compressed air is introduced to achieve uniform mixing of gas and powder.

Safety Protection Mechanisms
Pressure Relief and Explosion Prevention: A burst disc is installed at the top to automatically release pressure in case of overpressure; during tank change, dust-laden gas is filtered through a dust collector before discharge;
Inerting Protection: When injecting bituminous coal, nitrogen is filled to maintain an inert atmosphere inside the tank to prevent explosions;
Structural Reinforcement: Made of Q345R steel plate, the manhole cover adopts a groove sealing structure, improving fatigue resistance by 30%.