Why is feedwater chemically treated before entering the boiler?

Feedwater is chemically treated before entering the boiler primarily to prevent issues that may arise during the heating process. Scale-forming salts, if left untreated, can accumulate on the heat transfer surfaces within the boiler and lead to reduced efficiency and potential operational failures. By treating the feedwater, these salts are transformed into nonadhering sludge, which can then be more easily removed from the system.

The treatment specifically targets the solubility and behavior of various contaminants. When scale-forming substances, such as calcium and magnesium salts, are managed properly, they do not adhere to surfaces and instead remain in a manageable form. This is crucial because it helps maintain the integrity of the boiler and ensures efficient heat transfer, ultimately supporting stable operation and longevity of the equipment.

Other considerations, such as improving boiler pressure, removing oxygen, and enhancing thermal efficiency, play a role in the overall maintenance and operation of a boiler, but the primary focus of the chemical treatment of feedwater is to manage scale formation effectively.