Bilingual Monthly Magazine Focusing On Boiler & Steam Systems

The future of the industries is very bright, as water issue is becoming very scary so it is very essential to re-use the same to reduce the requirement of fresh water.

The available water should be got rid of all the impurities before it is used in boilers as feed water. These impurities may be in the suspended or dissolved state. The first group includes mud, silt, clay and silica (SiO ) either in suspension or in colloidal form. The 2 second group includes calcium carbonate (CaCO ) calcium bicarbonate [Ca (HCO ) ], 3 32 calcium sulphate (CaSO ), magnesium bicarbonate [Mg(HCO ) ], magnesium 4 32 carbonate (MgCO ), sodium bicarbonate, sodium sulphate, magnesium sulphate, 3 nitrates of calcium and magnesium; chlorides of calcium, magnesium and sodium; iron oxide, silica; and gases such as oxygen and carbon dioxide.

These impurities deposit on heat transfer surfaces in a power plant. These materials like dirt and scale have low conductivity and therefore impede heat transfer severely. Deposits of scale forming impurities on boiler tubes will restrict the water flow also. It can also raise the metal temperature with resultant tube rupture. All these troubles arise due to one or more of the following items resulting from the water impurities.

Gases in the atmosphere such as oxygen, nitrogen, and carbon dioxide are brought into the water supply with rain. On the ground, water dissolves and picks up minerals that would be detrimental to the boiler unless removed. Organic matter also must be removed from the boiler water, and raw water contains both dissolved and suspended solids.