What is the role of sodium sulfite in a boiler?

Sodium sulfite plays a crucial role in the operation of a boiler by preventing oxidation of the boiler drum and tubes. In the presence of water and oxygen, the metallic surfaces within the boiler can undergo corrosion and degradation due to oxidation. Sodium sulfite acts as an oxygen scavenger, reacting with dissolved oxygen in the water to form sodium sulfate and thereby reducing the amount of free oxygen present. This chemical reaction significantly decreases the risk of corrosion, which can lead to leaks, reduced structural integrity, and ultimately premature failure of the boiler components. Maintaining the integrity of the boiler system is vital for efficient operation and safety, which emphasizes the importance of sodium sulfite in the water treatment process.

The other options do not accurately represent the function of sodium sulfite in this context; for instance, it does not have a role in increasing pressure, enhancing water circulation, or improving heat transfer, which are separate considerations in boiler operation and maintenance.