Stacks and flares are ideal environments for promoting corrosion. A typical coal fired combustion gas stream will consist of several acidic compounds like:
SO2
SO3
NOx
HCl
Add in significant amounts of moisture, then raise the temperature to anywhere from 100 to 200+ºC and you can understand how even the most robust stack and flare sampling systems corrode after just a few years.
See how SilcoTek coatings stand up to high heat:
Plants, and refineries in coastal locations experience even higher corrosive damage due to exposure to chlorides. SilcoTek corrosion resistant coatings demonstrate significant resistance to chloride attack.
Making matters worse, stack corrosion is becoming more severe due to:
High sulfur content in feedstock/fuels
Use of alternative fuels containing high levels of chlorides
Better filtration: Reduced particulate emissions resulted in less alkaline dust carryover. Less opportunity to neutralize acids.
Maintaining stack and flare sampling systems is costly. Replacement costs can run into the tens of thousands of dollars, so extending the life of stack probes and sampling systems is critical to plant operations.
Engineers often turn to exotic alloys (expensive and adsorptive to sulfurs, mercury and ammonia) or to conventional coatings.
Conventional coatings can have significant drawbacks:
Limited temperature capability, cannot withstand stack or flare temperatures
Delamination
Poor abrasion resistance
SilcoTek coatings offer the most inert surface and corrosion resistance while withstanding extreme conditions found in stack environments.
