Dry Scrubber Turning Vane Life Increased
NanoSteel coating provides improved erosion resistance for longer service life
Spray drying absorption (dry scrubber) systems remove sulphur dioxide from flue gas at fossil fuel power plants.
At the top of dry scrubber units, hot flue gas enters a dispersing unit at 300° F. Turning vanes on a fixed dispersion ring direct the gas flow into a rotary atomizer where it comes in contact with a spray mixture of fly ash, lime milk and cooling tower blowdown water that absorbs sulphur dioxide into alkaline droplets. The water evaporates immediately and the droplets are converted into a powder that is discharged from the chamber.
Turning vanes on the dispersion ring are fabricated from untreated A36 carbon steel. During service, fly ash particles in the flue gas cause material loss from severe erosion.
To reduce material loss on turning vanes inside dry scrubber unit at a coal fired power plant in Arizona, a NanoSteel SHS 9172 TWAS thermal spray coating is applied for resisting erosion.
The NanoSteel SHS 9172 TWAS coating provides resistance to severe erosion for reducing material loss, improving performance and extending the service life of turning vanes on the fixed dispersion ring.
Material loss from severe erosion
Arrows show where erosion has worn through untreated steel vanes
NanoSteel coating extends vane life
NanoSteel coating applied where the most severe erosion occurs prevents surface material loss and extends vane life