IGS Coatings for Sootblowers in PC-fired Boilers
IGS has developed highly erosion resistant materials and Cetek® anti-slagging technology to address sootblowing environments in nose arches, superheaters, and reheater tubes of pulverized coal boilers. Utilizing our experience in high erosion applications, IGS has developed proprietary materials to withstand the aggressive conditions associated with air and steam sootblowing.
Steam Soot Blower Erosion of Boiler Tubes
Utilities use either steam or air to clean boilers. Soot blowers are installed at various boiler locations like water-walls, superheaters, reheaters, economizers and air pre-heaters. As boilers have become larger and the quality of fuel has deteriorated, this has required a larger amount of cleaning to remove the soot, also commonly referred to as slag. Slagging, fouling or soot build-up can have a big impact on the operating efficiency of a boiler. When the slag builds up on the tubes, the heat transfer decreases which lowers the temperature of the steam going to the superheated portion of the system, therefore decreasing the overall efficiency of the system.
As the steam or air is processed through the sootblower, this action results in increasing air velocity in that isolated area which has been known to erode the surrounding surfaces and also cause minor temperature cycling which can fatigue the boiler tubes. The thinning of the furnace walls, superheater, reheater, economizer and air pre-heater tubes finally leads to material failures and leaks.
On-Site Coatings Mitigating Sootblower Metal Wastage
IGS has developed two methods to solve sootblower wastage using two different technologies. Both technologies can be used standalone but the combination of both is what will provide the best solution. There are two concerns when we look at sootblower protection, these are:
- The slag adhering to the tube
- The sootblowers eroding the tube during operation
To address these concerns, IGS leverages its unique products to find a solution that is both erosion resistant and ‘non-stick’ to limit the slag from adhering to the tube in the first place.
By applying IGS’s product line of Cetek® Anti-Slagging technology, the boiler tube surface can be coated with a very smooth, slick material that restricts the slag from building up in the first place. This is effective in superheat regions, nose arches, and waterwall locations. Furthermore, if there is less slag on the tubes, you can also do less sootblowing which will further prolong your tube life.
HVTS Cladding to Protect Metal from Sootblowing Erosion
To address the second point (sootblowers eroding the tube during operation), IGS applies a high alloy material using its HVTS (High Velocity Thermal Spray) process to produce a homogenous (particles typically <50um), hard and tough material to withstand the energy generated by the sootblower.
The combination of these two technologies ensures our customers have the protection they need to have less slagging in their boilers, which will lower the flue exit gas temperatures (FEGT) and improve the heat rate by having more tube exposed to absorb the heat.
Less Slag = Better Absorption = Lower FEGT = Improved Heat Rate/Boiler Optimization
IGS Experience Cladding Metal Inside PC boilers
IGS has applied over 1 million square feet of coatings to address sootblower erosion and slag build up over the past three decades to become the trusted provider for sootblower protection. Our ability to combine best-in-class products and application services will limit the slagging and provide the erosion resistance required for these locations.