The reliability and the life expectancy of boilers and related equipment have been compromised due to severe chemical attack resulting in corroded tubes at different locations in the boilers. Although it seems that a chelant is responsible for the thinning, glassy, smooth, and featureless surfaces so characteristic of the chemical attack, ultimately, it is an all polymer program which has induced this corrosion. However, an all polymer program, if applied properly, would not create this corrosion. The severe corrosion experienced with the all polymer program resulted from misapplication. including high levels of residual polymer, low hydroxide alkalinity, and high cycles of concentration in conjunction with prior acid cleaning, which produced clean boiler tubes. This paper not only attempts to investigate this corrosion, but further, it recommends possible methods to mitigate polymer corrosion in the future and enhance the overall condition of the boilers.
Keywords: boilers, corrosion, polymers, passivation, redeposition. chelation, buffer, cycles of concentration, high purity water, sequestration