Circulating Fluidized Bed (CFB) Boiler Erosion
As a result of the 1978 PURPA Act in the United States, individual power producers began building power plants that generated electricity to the grid and supplied steam to nearby host facilities. Many companies chose circulating fluidized bed boilers (CFBs) as their steam generator of choice due to their ability to provide a clean and efficient way of burning a number of different fuels, primarily bituminous coal, waste coal, and biomass.
However, due to CFB boiler design characteristics, the process of burning these types of fuels has led to well known maintenance issues of boiler tube erosion and/or corrosion. Circulating fluidized bed boiler erosion typically occurs in such critical areas as such as the refractory line, field weld lines, corner tubes, roof tubes, areas around the cyclone openings, as well as the superheater and economizer tubes. These areas must be protected, often on a repetitive, ongoing basis, to reduce the plant’s effective forced outage rate (EFOR).
Integrated Global Services designs and installs erosion and corrosion resistant coatings in the shop or field for tube protection. Our UTEx 5-400 cladding system, as conveyed through our proprietary High Velocity Arc Spray (HVAS) application process, produces an excellent barrier against the effects of gouging and general erosion, and can be built up to a significant thickness for extra erosion. Our High Velocity Oxygen Fuel (HVOF) applied UTEx 1-014, 1-020, and 1-020A cladding materials are solutions which counteracts specific abrasive wear and elements of corrosion in certain CFB units. Finally, based on the environment, many of our cladding systems employ unique sealants and/or top coat ceramics, which afford additional corrosion, erosion, and wear-pattern recognition benefits to the operator.
A comprehensive understanding of CFB design, fuel properties, and the resultant mechanisms of erosion and/or corrosion is critical to proper circulating bed boiler maintenance.