In this program chelating agents viz., EDTA, NTA, etc., are added to feed water. These salts form water soluble complexes with calcium & magnesium and prevent them from precipitating. In case they form scales, these salts de-stabilizes the crystalline growth. This system of treatment is discouraged as the salts may carry over with steam and break into acidic components which may cause corrosion in post boiler sections. This method of treatment is implemented in boilers having operating pressure within 20Kgscm2 where soft & raw water are used as boiler feed water. The above treatment should be used in conjunction with polymeric sludge conditioners for better results. In this method of treatment precipitation of calcium & magnesium, either partially or completely, are induced by maintaining higher pH & higher alkalinity. The residual hardness, if present, should be controlled with the addition of polymeric sludge conditioners.

In this program chelating agents viz., EDTA, NTA, etc., are added to feed water. These salts form water soluble complexes with calcium & magnesium and prevent them from precipitating. In case they form scales, these salts de-stabilizes the crystalline growth. This system of treatment is discouraged as the salts may carry over with steam and break into acidic components which may cause corrosion in post boiler sections. This method of treatment is implemented in boilers having operating pressure within 20Kgscm2 where soft & raw water are used as boiler feed water. The above treatment should be used in conjunction with polymeric sludge conditioners for better results. In this method of treatment precipitation of calcium & magnesium, either partially or completely, are induced by maintaining higher pH & higher alkalinity. The residual hardness, if present, should be controlled with the addition of polymeric sludge conditioners.