Header - Chimney technology



5 ideas

Fossil fired power stations worldwide are exposed to increasing pressure to operate with maximum efficiency and minimum emissions.

A power station built in 2020 is significantly more efficient, both economically and environmentally, than a power station built in 2000, 1980, or 1960. In spite of these technical leaps, chimneys today are essentially the same as forty years ago, except for the fact that they use different materials of construction for their internal flues.

This paper will suggest five concepts that should be considered when any new chimney is built, either for a new power station or for an existing power station that is being modernized.

The five concepts concern the use of:

FGD Wet Stack

FGD Wet Stack
Using an FGD Wet Stack, instead of reheating flue gas prior to entry into the power plant chimney, offers significant advantages.
  • Significantly reduced cost for power plant construction
  • Operating costs are substantially lower
  • Requires the use of well-proven construction materials and systems
  • When using a HadekTM chimney lining placed in the 45° High Velocity Pattern, no spitting occurs at flue gas velocities up to 22.9 m/s

New Chimney Design

New Chimney Design

Hadek’s well proven technology for a concrete chimney protected by using the borosilicate lining technology.

  • Cost & time reducing technology for chimneys of up to 200 meters high
  • Saves 30% in construction costs
  • Reduces construction time by approximately 5 months
  • Building one NCD chimney per unit is more economical and requires very short FGD outlet ducts

Wet-Ready Guide Vanes

Wet-Ready Guide Vanes

By using the special Wet-Ready Guide Vanes instead of normal guide vanes in the chimney entrance of FGD Wet Stacks, harmful spitting can be avoided.

  • Capability to drain liquid from the flue gas stream, whilst reducing chimney inlet pressure losses by 70%
  • Significant pressure loss reduction
  • Improved environmental performance

Top Diffusor

Top Diffusor

The low flue gas temperature in FGD Wet Stacks caused reduced draft as well as positive pressure, especially for power stations operating in hot climates. To this purpose, Hadek developed a specific diffusor for NCD (New Chimney Design) chimneys.

  • Increase of draft in the chimney by 60%
  • No damaging positive pressure
  • Substantial reduction of operating and maintenance costs
  • Emissions are significantly reduced
  • Risk of harmful stack liquid discharge (spitting) is minimized

45º High Velocity Pattern

Hadek's lining placed in the 45º High Velocity Pattern

Placing the HadekTM lining under a 45-degree angle avoids the use of horizontal joints and thus allows for higher flue gas velocities without causing harmful spitting.

  • Allows for gas velocities up to 22.9 m/s
  • Significant reduction of operating and maintenance costs
  • Minimization of the risk of harmful stack liquid discharge (spitting)
  • Reduction of emissions
  • Substantial reduction of operating and maintenance costs, whilst no additional construction costs