Epoxy Vinyl Ester Polymer Lining for Duplex UNS S32205/S31803 Alloy FGD Absorber Modules

摘要

In order to meet more stringent EPA guidelines, the coal-fired power industry must now build or retrofit their facilities with flue gas desulfurization (FGD) systems. A critical part of these systems is the FGD absorber. A common building material for the absorbers has been duplex UNS S32205/S31803 and UNS S32550 alloys; however, the UNS S32205/S31803 alloy is showing signs of premature corrosion throughout the industry. The root cause of this corrosion is still under investigation, but with some absorbers lasting less than 18 months, a repair regimen is sorely needed. This paper will discuss the issues surrounding UNS S32205/S31803 alloy corrosion as well as methods to rehabilitate and protect both old and new absorbers with epoxy vinyl ester polymer lining. The paper will also review the proper cleaning, surface preparation, application process, and choice of epoxy vinyl ester polymer lining to protect UNS S32205/S31803 alloy and prevent its premature breakdown in this environment.