What term describes unevaporated boiler water carried out of the steam drum due to malfunctioning internals?

The term that describes unevaporated boiler water carried out of the steam drum due to malfunctioning internals is known as priming. Priming occurs when steam bubbles rise rapidly to the surface of the water in the boiler and carry liquid water along with them into the steam lines. This situation often arises from issues such as excessive water levels in the boiler, surging, or mechanical malfunctions within the boiler that affect water separation.

When priming occurs, the presence of liquid water in the steam can cause issues in the steam system, including decreased efficiency and potential damage to equipment. It's crucial for operators to manage boiler conditions carefully to prevent priming and ensure a steady supply of dry steam for operational needs. Understanding this phenomenon helps machinists address boiler performance issues effectively and maintain system integrity.