It is common practice in modern power utility condensers to treat boiler feedwater to reduce corrosion of ferrous components in the system. Ammonia treatments are often used to adjust pH to a sufficiently high value to virtually eliminate corrosion of iron. Organic amines, such as cyclohexylamine, hydrazine and morpholine, may also be added to the boiler feedwater to scavenge oxygen and reduce corrosion. Although the basic amines are not normally considered harmful to condenser tube materials, their breakdown products may contain ammonia. Boiler feedwater treatments, although beneficial to ferrous components, can, therefore, be detrimental to non-ferrous materials, particularly some copper alloys. Ammonia can be a highly aggressive corrodent in the presence of oxygen since it is highly soluble in water and can become concentrated in the condensate. Normally, ammonia concentrations in the main body of the condenser are low and, coupled with the very low oxygen concentrations, problems are not too often encountered in these regions. High ammonia concentrations can occur in the air removal section together with relatively higher concentrations of oxygen and other gases. Problems associated with condensate containing ammonia are most often encountered in condenser air removal sections.
