Coal dust dampers are used in pipings of coal fired power plants between mills and burners. The purpose of these dampers is to shut-off individually the coal feeding line upstream the burner when the corresponding mill is out of service.
The coal dust dampers are of heavy duty design with an optimised flow pattern to prevent deposit formation. In opened position the damper flap is positioned completely out of the dust stream which results in full orifice cross section for less pressure drop.
The damper type KSK-HLK comes with an additional hot-air connection. In closed position of the main damper blade hot air injected ensures automatic cooling and cleaning from remaining dust at the burner port. As a result the burner is protected against illegal high temperatures and the boiler is protected against explosion.

Application areas
  • Safety damper in coal dust pipes on the basis of DIN EN 12952-9 “Requirements for firing systems for pulverized solid fuels”
Nominal size: DN 150 to DN 800
Operating pressure: max. 0.5 bar g
Operating temperature: max. + 300°C

  • Completely unblocked flow cross section
  • Reliable shut-off of the medium due to robust seat sealing system
  • Shaft sealing certified in acc. with the Clean Air Guidelines (TA-Luft) for full tightness towards the exterior
  • Very short positioning times compared to simple shut-off valves
  • Compact and cost-efficient solution - only one valve instead of two conventional ones
When in its closed position, the flap plate is pressed onto the flap seat by the drive shaft and the internal lever, ensuring a dust-tight shut-off. At the same time, the hot-air connection is opened to cool down the burner gun. When the coal dust flap is opened, the flap plate is moved around 90° and unblocks the entire flow cross section. In this position, the flap plate does not interfere with the flow but seals off the hot air supply completely.

Technical features
Valve body: -Welded steel construction with inspection opening for service and maintenance while the valve is installed.
-100% free orifice cross section; the flap plate is entirely moved away from the flow.
-Only small dead spaces to prevent deposit formation.
-Flap plate is flexibly mounted for a perfect sealing of both housing seats.
Seat sealing system: Alternatively metallic sealing made of stainless steel, or soft sealing
Shaft sealing: Shaft sealing towards the exterior by packing seal kits, with test connection on the coal dust side
Actuator type:
  • Manually actuated by means of a self-locking gear box
  • Electric actuator with gear box
  • Pneumatically driven rotary drive, double or single acting, with spring reset (preferably for short positioning times)
Process connection: Alternatively with welding ends or flange connection, both available in EN or ANSI design
Special features:
  • Optionally available with hard-facing for wear protection, or with ceramic lining
  • Optionally available with exchangeable seat ring
  • Optionally available with anti-surge protection according to NFPA 85
  • Optionally designed for operating temperatures of up to 400°C