Dry Scrubber Wall Surface Loss Reduced
NanoSteel coating provides severe corrosion resistance for extending dry scrubber chamber service life
Spray drying absorption (dry scrubber) systems remove sulphur dioxide from flue gas at fossil fuel power plants. This process occurs inside a chamber fabricated from A36 carbon steel.
As flue gas enters the chamber at 300° F, a mixture of fly ash, lime milk and cooling tower blowdown water is sprayed to absorb sulphur dioxide into alkaline droplets. As the water evaporates almost immediately, the droplets are converted to a powder which falls to the bottom of the chamber for removal.
Where spraying occurs, a combination of corrosion scale, fly ash and lime milk containing high concentrations of calcium sulfite, calcium sulfate and chlorine can build up on the ID surface of the chamber wall and cause severe corrosion and pitting damage. This damage can result in significant wall material loss and cause the chamber to buckle and fail.
To reduce material loss inside dry scrubber chambers at a coal fired power plant in Arizona, a NanoSteel SHS 7570 TWAS thermal spray coating is applied for resisting corrosion and pitting.
The NanoSteel SHS 7570 TWAS thermal spray coating provides resistance to severe corrosion and pitting damage, reduces wall material loss and extends the service life of the dry scrubber chamber.
Corrosive material build up
Corrosion scale, fly ash and lime milk builds up on chamber ID wall surface
Resulting Catastrophic Chamber Wall Failure
Significant surface material loss caused the wall of this dry scrubber chamber to buckle and fail
NanoSteel Coating Prevents Material Loss
NanoSteel coating provides severe corrosion resistance, reduces wall material loss and extends the life of the dry scrubber chamber