What are the factors responsible for corrosion of the feed water lines, boiler tubes, drums and condensate lines ?
(a) Dissolved Oxygen in the feed water will cause Pitting corrosion in the feed water lines, boiler tubes, drums, steam lines, turbines and return condensate lines. (b) Carbon-di-oxide present in the feed water normally does not affect the feed lines and boiler tubes. But Co2 affects the return condensate lines. Co2 goes along with steam from the boiler and whenever steam condenses Co2 dissolves in the condensate forming Carbonic acid which attacks the metal. Grooving type of corrosion is normally formed due to Carbonic acid attack. (c) Hydrochloric Acid, Nitric Acid and Sulphuric Acid are formed when Chlorides, Nitrates and Sulphites of Calcium and Magnesium are hydrolyzed by the water in the boiler and they corrode the drums and tubes. How can we remove O2 and Co2 from boiler feed water ? Deaeration by the use of mechanical deaerators is widely used to remove dissolved gases from water and thereby control corrosion. In particular it is used to remove oxygen from boiler feed water sys
