🔍 Key Concepts

• Boiler water circulation and where heavier particles tend to settle • Difference between surface blow (continuous blow) and bottom blow systems • Location and function of the water drum vs. steam drum in a typical marine boiler

💭 Think About

• Ask yourself: where do heavier solids and sludge naturally collect in a boiler—near the water surface or at the very bottom? • Which part of the boiler (steam drum or water drum) is connected to a valve that is used intermittently and opened briefly at high flow to clear out settled solids? • Think about how operators normally remove scum (foam, oil) compared to how they remove mud or sludge—are those handled by the same valve?

✅ Before You Answer

• Identify whether bottom blow is mainly for surface impurities or settled solids/sludge. • Confirm which drum (steam drum or water drum) is associated with scum removal versus sludge removal. • Consider if a bottom blow valve is routinely used to control water level, or if that would be a last-resort, non-standard action.