Boiler scale prevention
Scale and Corrosion Control
What is boiler scale control chemical? A polymer and phosphate are the most popular chemicals used to minimize the scaling tendencies within a steam boiler.
How much of the chemical do I feed? In theory you need 7 ppm of phosphate within a boiler per 1 ppm of hardness to prevent scaling. Excess is added protection against hardness excursions that may occur.
Boiler oxygen scavengers
Removal of Dissolved Oxygen
What is a boiler oxygen scavenger? The most popular dissolved oxygen scavenger is sodium sulfite. Sodium sulfite is commonly purchased in powder or 38% form. 19% solutions with a neutral pH is favorable for those wanting to eliminate sodium hydroxide from their water treatment program.
Where so I feed the sulfite? Sulfite is fed as far back in the boiler water system as possible. Preferably into the center of the water storage of a deaerator or feed water tank. Any sulfite residual in the boiler means you have no oxygen present within the boiler. Excess sulfite is maintain as a buffer and safety precaution.
What is boiler alkalinity? The most popular boiler alkalinity chemical is sodium hydroxide. Sodium hydroxide is used to increase the boiler water pH. This allows the polymer to properly function, maintains silica in solution, and reduces over boiler tube corrosion rates.
How much boiler alkalinity do I need? The most popular pH range for steam boilers is above 10.5 pH or at a 3:1 ratio to silica.
What is a boiler amine? The most popular boiler amines are blends of Cyclohexylamine, Morpholine, and Diethylaminoethanol.
Where and how do I feed the amines? Ideally you want to fed the amine directly into the steam header. You may feed the amine to the boiler feedwater tank, but you will use about 10% more product.