Description
OXYAMINE is a new technology oxygen scavenger designed to substitute Hydrazine and Sulfite, which are traditionally, used for this purpose in all boilers high and low pressure.
Benefits
- It is suitable for boilers up to 125bar.
- It is a very efficient oxygen scavenger.
- Forms a passivating protective film (F3O4 – Magnetite).
- It does not increase the total dissolved solids.
- It is sufficiently volatile so that it can protect against oxygen corrosion in the entire boiler system including the steam – condensate return lines.
- Due to its unique property of being volatile it controls carbon dioxide corrosion in the condensate return line systems.
- The product is non-toxic.
Limitations of Sulfite and Hydrazine
Equations 1 and 2 show the reaction of Sulfite and Hydrazine with oxygen.
2 Na2SO3 + O2 = 2 Na2SO4
N2H4 + O2 = N2 + 2 H2O
Each however has limitations.
Sulfite increases the total dissolved solids in the boiler water through the formation of Sodium Sulfate. Therefore boiler blow down must be increased resulting in greater chemical and fuel costs. Sulfite is only an oxygen scavenger and does not form a protective film of black magnetic iron oxide (F3O4, magnetite). This magnetite film passivates and protects the metal surfaces.
Hydrazine is not as effective as sulfite is as an oxygen scavenger and it is very toxic.
Hydrazine has been classified as a suspect carcinogen by OSHA and NIOSH. It has been regulated by the FDA to exclude any use that might come in direct contact with food.
Both Hydrazine and Sulfite are non – volatile. (Hydrazine has limited volatility). and they do not protect the steam – condensate return line system. It is obvious that the need for new oxygen scavengers is essential.
Application, dosage & control
For an untreated system an initial dose of 100-200 ml per day then dosing should
be controlled so that the deha residual in the condensate is between 0,1 – 04, ppm
according to the table below:
Test Result Condesate PPM DEHA
0.00 – 0.1
|
0.1 – 0.4
|
+0.40
|
Increase dose by 25%
|
Maintain dose
|
Decrease dose by 25%
|