With over 25 years of experience applying protective coatings in coal power boilers around the world, IGS has developed innovative solutions to extend the life of the existing equipment and to provide reliable, long-term protection with significant cost and time savings to our customers. A combination of proprietary alloys and unique application technology allows us to provide both erosion and corrosion solutions to components within the coal and lignite-fired boilers.
Coal and Lignite Fueled Boilers
Coal-fueled power plants are the most widespread electricity-generating technology, providing the world’s main source of energy. Although there is a growing focus on renewable energy provision, the International Energy Agency (IAE) predicts that fossil fuels will still account for more than 70% of the energy market in 2035.
Coal-fired boilers frequently exhibit erosion, corrosion, or a combination of both that subsequently damages these assets. The two most common types of boilers are fluidized bed boilers and pulverized coal-fired boilers. In this section, we will explore common issues arising in this equipment, and how IGS can solve them. We offer services for CFB, Pulverized coal, FGD (Flue Gas Desulfurization) Units, Economizers, Soot blowers, and SCR (Selective Catalytic Reactors). With our decades of global experience in this area, we likely have a proven solution for you.
Corrosion of Coal-Fired Boilers
CFB Boiler Fireside Corrosion-Erosion
CFB boilers operate by combusting fuel in a fluidized bed of non-combustible particles. As these bed material particles recirculate in the furnace, they cause wastage of the furnace waterwall and evaporator panels. This corrosion-erosion mechanism is an unavoidable consequence of this boiler design. The wastage develops frequently at refractory to waterwall/evaporator interface, field weld joints in the furnace, and around the cyclone inlets. We provide HVTS metal-based coatings to mitigate corrosion-erosion of waterwall panels of circulating fluidized bed boilers.
Outside of the tube wastage, several components require regular maintenance to keep the units running optimally. These include vortex finders, loop seals, expansion joints, bed nozzles, and tube replacement.
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Pulverized Coal Boilers’ Metal Wastage
Pulverized Coal (PC) Boilers generate thermal energy by burning pulverized coal injected through a combustion air stream to the burners in the firebox. As this coal combusts, compounds such as Sulfur react with the surrounding iron-based materials to cause metal wastage. Common issues include:
- waterwall fireside corrosion
- lower slope erosion
- upper nose arch erosion
- sootblower erosion
- corrosion assisted thermal fatigue
- fouling/slag build up
With our metal and ceramic coatings, we prevent fireside corrosion of PC-fired boilers, as well as erosion and thermal fatigue.
Flue Gas Desulfurization (FGD)
We provide corrosion resistant coatings for boiler economizer tubes.
Our highly erosion resistant materials and Cetek® anti-slagging technology address sootblowing environments in pulverized coal boilers. Utilizing our experience in high erosion applications, we spray proprietary materials on-site that withstand the aggressive conditions associated with air and steam soot-blowing.
Selective Catalyst Reactor (SCR)
IGS designs, engineers, manufactures the longest lasting large particle ash (LPA, or “popcorn ash”) filtration systems in the world. Typical filtration screens protecting catalysts within SCR systems have proven to be short-lived and unreliable, resulting in frequent clogging of the catalyst with LPA, decreasing NOx reduction performance. In contrast, IGS’s patent-pending NoNOx™ Components have been in service for years in some of the most aggressively run SCR systems in the world, having maximized catalyst maintenance cycles, reducing the likelihood of unplanned downtime, and significantly reducing the lifetime cost of SCR systems.
The IGS Solution
For each of the pieces of equipment in a coal plant listed above, IGS has developed innovative and proven solutions to address metal wastage issues. With a full variety of services like Mechanical and Refractory Services, High Velocity Thermal Spray, Catalyst Protection Options and Cetek® anti-slagging technology, IGS provides life extension solutions that minimize the customer’s operating costs, and maximize asset value. We understand that the combination of material, application technology, and a skilled workforce is paramount to providing the very best solutions to the boiler protection.
- We custom engineered our HVTS claddings to provide fit for purpose erosion and/or corrosion benefits depending on your specific application and performance objectives.
- IGS Maintenance teams are a highly skilled non-union workforce to focus on the key equipment in power boilers which include both mechanical and refractory services.
- The IGS Environmental team has developed patented technology to protect the SCR’s from large particle ash (LPA). In combination with air cannons, sonic horns, and secondary screens we provide a 95% Clean SCR Guarantee.
- IGS’ line of Cetek® ceramic technology provides anti-slagging technology which lowers the flue exit gas temperature (FEGT) and improves the heat rate of the boiler.