OVERVIEW: Exhaust stacks in a methane gas power plant are genuine workhorses. There’s no time for rest, and they need to be productive 24/7. Obviously, corrosion protection is a real challenge, but one that is critical to keeping exhaust stacks performing as efficiently as possible, but also in preventing power outages when maintenance is required.
Methane gas co-generation plant exhaust stack trials
Restoring these exhaust stacks to their former glory was no easy feat. The 15-year-old plant had started show signs of premature corrosion within four years of commissioning. The task to refurbish the giant exhaust pipes and manifolds was entrusted to Chemcote. Not only was spark-free surface preparation a strict requirement, the new protective coatings needed to be applied on a 105°C surface temperature, all while the plant remained online.
The initial step involved mobilising site assets including plant maintenance personnel, conducting safety assessments, and securing required access.
Prior to any coating applications, the stacks needed to be mechanically cleaned using a wire bush. Two coats of Epo-chem™ RL 500PF, a surface and moisture tolerant zinc rich epoxy, were then applied.
Mobilize to site and work in with plant maintenance personnel to ensure all risks are assessed and reduced where possible
Obtain safe access and mechanically clean, using a wire brush only
Application of 2 coats of RL 500PF with a nominal DFT of 300µm
Over the past five years, Chemcote have inspected the exhaust stacks, and no signs of corrosion or coating failure have been evident. The protective solution offered plant maintenance engineers the peace of mind that the stacks now had a life expectancy of more than 10 years before any signs of corrosion would be visible.