WATER TREATMENT
What happens when a piece of metal is immersed in water?
CORROSION!
SCALE!
The reason to treat Water is to avoid or reduce Scale
Boiler Water Treatment
Reasons to treat boiler water:
Avoid scale and corrosion by eliminating:
Dissolved gases
Hardness salts
Various pollutants (oil, acids, mud etc.)
Heat transfer surface; boiler tubes
Boiler tubes must be kept clean for safe and reliable operation
Water Chemistry
Hardness salts
Magnesium and Calcium react with CO2 forming
Calcium carbonate and -bicarbonate
Magnesium carbonate and -bicarbonate
In hot boiler water, the hardness salts may crystallize and adhere to hot
surfaces forming insulating scale.When chemically treated, the hardness
salts form a sludge easily disposed of by blowdown.
Low Condensate pH -absorbed CO2
Chemical Treatment
Neutralising amines
Avoid leakages in the condensate system
Increase hotwell temperature
Dissolved gases
Carbon dioxide, CO2
Oxygen, O2
CO2 and O2 are present in air that is absorb by water. The amount of gases
present in water is dependent on the water temperature. In steam systems,
without treatment CO2 and O2 will lead to corrosion.