Scales formation inside boilers is the
result of precipitation of impurities and suspended solids present in the feed water,
used for boiler operations. Feed water contains dissolved minerals (Chloride,
Sulphates, Silicates of Sodium, Potassium, Calcium, Magnesium, Barium) and
impurities (Oil Contaminants, Sludge, Lime) that in due course get
accumulated over the boiler internal surfaces, leading to the formation of
scales.
Boiler Chemicals
Boiler chemicals treat feed water as well as boiler
internal surfaces. As feedwater gets settles, the dissolved solids and
impurities begin to precipitate at the base, and with continuous accumulation
of salts, when they exceed their solvency levels form scales on the internals,
needing boiler water treatment.
The presence of calcium, magnesium
salts, and a high concentration of silica is the major causes of scale
formation. It consists of carbonates, bicarbonates, sulfates, etc. Along with
dissolved salts, there are also some suspended solids in the boiler feedwater
that get precipitated as sludge. These are not hard as compared to scales, but
if it is overlooked, sludge gets hardened due to continuous heating in the
boiler.
Characteristics
of most common deposits
•
Carbonate deposits, large granules, and porous forms dense and uniform
pitting and scaling over the surface
•
Sulphate deposits, crystalline, fine particles but a bit harder and
denser than a regular carbonate deposit
•
Hard and not so easy to remove silica deposits, extremely small, forms a
dense and impervious scaling
•
Iron deposits
How does scale form in the Boiler System?
A large
number of components dissolved in the water gets deposited on the surface of
the boiler system, leading to impurities in the water. The precipitation of
impurities from the feed water on the heat transfer or metal surface on the
boiler causes scale formation. At the point when this feed water goes into the
heater, it begins to precipitate at the base, the salts being abandoned.
Continuous expanding of salts and when it crosses the solubility limit of
water, the salts get saved as scales. In continuous operation of the boiler, it
forms a layer on the metal surface which affect the heat transfer in the
boiler.
The presence of calcium, magnesium salts, and a
high concentration of silica is the major causes of scale formation. It also
consists of carbonates, bicarbonates, sulfates, etc. Along with dissolved
salts, there are also some suspended solids in the boiler feedwater that get
precipitated as sludge. These are not hard as compared to scales, but if
it is overlooked, sludge gets hardened due to continuous heating in the boiler.
If the
feed water is not treated properly then the boiler can suffer from poor
efficiency and permanent damage to equipment, which may shorten its life and
cause them to explode due to excessive heat.
Boiler chemicals are designed to remove mineral scales, metal
oxide, hard deposits of water scale, iron oxides, oily contaminants, sludge,
lime, and greasy deposits from the boiler internals. Using these chemicals
regularly ensures the protection of system metallurgy, providing a long service
life for the boiler system.
Features & Benefits:
·
Cleans effectively and efficiently
·
Prevents scale, sludge formation, corrosive deposition, etc.
·
Removes oil and grease effectively
·
Reduce maintenance costs and ensure the long-term service life
Learn More: https://www.chemtexltd.com/products-and-solutions/water-treatment-chemicals/boiler-water-treatment/