There are three main chemical programs to control corrosion in the condensate system, being 

• neutralizing amines, 
• filming amines and 
• mixtures of neutralizing and filming amines.

NEUTRALIZING AMINES are high pH materials which neutralize the carbonic acid formed in condensate systems. By raising and controlling pH level in condensate from 7.5 to 9.0, neutralizing amines retard acid attack and greatly reduce the amount of corrosion products entering the boiler.

The three primary neutralizing amines in use today are:

• Morpholine - a low distribution ratio product.

• Diethyleminoethanal (DEAE) - a medium distribution ratio product.

• Cyclohexylamine - a high distribution ratio product.

The distribution ratio is used to predict the amine concentration in the steam and condensate phases and impacts significantly regarding proper amine selection.

Distribution Ratio = Amine in Steam Phase   /  Amine in Condensate Phase

Neutralizing amines have low flashpoints and therefore can be fed directly to the feedwater or boiler water, or they can be fed directly into the steam header. The feed rate is based on the amount of alkalinity present in the feedwater. Neutralizing amines offer excellent protection against carbonic acid attack, but little protection against oxygen attack.

FILMING AMINES are various chemicals that lay down a vary thin protective barrier on the condensate piping protecting it against both oxygen and carbonic acid attack. The protective film barrier is not unlike the protection afforded an automobile by an application of car wax.

The protective film barrier is continuously being removed (a little at a time), requiring continuous feeding of the filming amine based on steam flow rather than feedwater alkalinity. 

Care must be taken to start this program slowly with an initial feedrate of one fifth that of the final feedrate to prevent the removal of old corrosion products from the system and their subsequent return to the boiler. Additionally, the filming amine should be fed using an injection quill to the steam header to insure proper vaporization and distribution throughout the steam system.

The formation of gunk balls (Gunking) can occur due to overfeed, contaminants in the condensate or wide pH swings causing deposits to form in low flow areas like steam traps.

COMBINATION NEUTRALIZING AND FILMING AMINES

 As its name implies, are the combination of neutralizing and filming amines and are a successful alternative to protect against both carbonic acid attack and oxygen attack. 

It combines the elevated pH approach to neutralize carbonic acid in conjunction with the protective barrier film approach.

The neutralizing amines, although they will elevate pH, main purpose is to provide better distribution of the filming amine throughout the condensate system which in turn helps to prevent gunking. 

As with filming amines it is better to be fed directly to the steam header utilizing an injection quill.

SUMMARY.  Clearly each program or approach has certain features and benefits as well as limitations. 

Each different set of operating conditions will tend to dictate the appropriate treatment that is required. The expected steam pressure, temperature, system metallurgy and the plants systems pH level all play an important role in determining the most effective treatment program. 

Clearly each program or approach has certain features and benefits as well as limitations. Each different set of operating conditions will tend to dictate the appropriate treatment that is required. 

The expected steam pressure, temperature, system metallurgy and the plant systems pH level all play an important role in determining the most effective treatment program.

OUR COMPANY

Offers a full range of neutralizing amines, filming amines and mixtures, as cover any system needs.

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