Blast furnace coal injection ball valve and coal injection check valve are core safety components of the blast furnace coal injection system, primarily used to control pulverized coal injection and prevent backflow of hot blast furnace gas. Key technical design
Design Points | Implementation Mechanism | Function
Elastic sealing structure | Valve seat equipped with high-temperature resistant spring (typically chrome-nickel alloy), providing continuous sealing preload | Compensates for wear and ensures zero leakage, achieving ANSI Class VI leakage rating
Fireproof and anti-backflow | Full metal sealing pair (e.g., hard alloy/ceramic coating), temperature resistance ≥1200°C; unidirectional flow design | Temporary sealing maintained even after seal ring burnout; prevents gas backflow.

Wear resistance enhancement | Ball made of tungsten carbide or silicon nitride ceramic (hardness HRC≥60), valve body inner wall hard-faced with wear-resistant alloy | Resists pulverized coal erosion, extending service life by over 3 times
Rapid response | Precisely matched spring stiffness and ball weight, valve closing response time ≤0.5 seconds | Prevents hot gas leakage during lance extraction
System coordination and parameters
Compatible equipment: Interconnected with coal injection lance, fluidizer, and air replenishment check valve to form a closed injection system.

Operating parameters:
Applicable pressure: 1.0~2.5MPa
Temperature resistance range: -29℃~450℃ (short-term tolerance 1200℃)
Diameter specifications: DN25~DN50 (main model DH-25)
Structural variants: Derived designs such as square type, date pit type, and elbow type based on installation requirements
Note: Current mainstream products (e.g., DH-25 coal injection ball valve) integrate self-cleaning grooves to reduce jamming failures caused by coal dust accumulation.