New York Low Pressure Boiler COF Practice

How does a deaerator remove oxygen and non-condensables?

1. By manually venting and flushing the system

2. By cooling and re-circulating the water

3. By using steam and chemical treatments

4. By straining and filtering the water

The correct answer is: By using steam and chemical treatments

The deaerator operates on the principle of utilizing steam to effectively remove dissolved gases, including oxygen and other non-condensable gases, from water. In this process, the incoming feedwater is heated with steam, which agitates the water and promotes the release of these gases. The increased temperature and agitation lower the solubility of gases in water, allowing them to escape more easily. Additionally, some systems may incorporate chemical treatments, such as oxygen scavengers, to further enhance the removal of oxygen. However, the primary method involves the thermal action from the steam, making it the core process by which a deaerator performs its function. This method is more efficient compared to options that rely on mechanical processes, such as manually venting or straining the water, as it directly addresses the solubility of gases in heated water. Therefore, utilizing steam, along with the potential for chemical treatments, is the most effective way to ensure that the water is free from harmful dissolved gases before it enters the boiler system. In this context, option C accurately reflects how a deaerator operates to maintain water quality in low-pressure boiler systems.