For maximum efficiency, where should sodium sulfite be added in a boiler system?

Sodium sulfite is primarily used in boiler systems to remove dissolved oxygen from the feedwater, which helps prevent corrosion within the boiler and associated piping. The deaerator is the optimal location for adding sodium sulfite because it is specifically designed to remove oxygen and other gases from the feedwater before it enters the boiler.

In the deaerator, the feedwater is heated, and the oxygen is driven off due to the high temperature and low pressure. Adding sodium sulfite at this stage ensures that the dissolved oxygen present in the feedwater is neutralized effectively before the water enters the boiler, helping to maintain the integrity of the boiler materials. This proactive treatment not only enhances the efficiency of the system but also extends the lifespan of the boiler by reducing the risk of corrosion and related failures.

Adding sodium sulfite at other locations, such as in the steam drum, feedwater tank, or directly into the boiler water, is less effective because these locations might not adequately reduce the dissolved oxygen levels before the water is heated in the boiler. Therefore, utilizing the deaerator for this purpose is the best practice for achieving maximum efficiency in boiler operation.