🔍 Key Concepts

• Difference between surface blow and bottom blow in boiler operations • Where dissolved and floating impurities tend to concentrate in a steaming boiler • Effect of blowing down on boiler water chemistry, especially alkalinity

💭 Think About

• Think about where the surface blow line is located in the boiler and what part of the water it removes. • Ask yourself: which type of impurities (heavy solids vs scum/foam) are more likely to be found at the water surface rather than near the bottom? • Consider whether removing some boiler water will or will not influence the concentration of treatment chemicals like alkalinity builders.

✅ Before You Answer

• Identify what bottom blow is typically used for, and contrast it with surface blow. • Verify which impurities are heavier and settle versus which float or form foam/scum at the surface. • Check whether any blowdown operation can truly have no effect on boiler water chemistry, or if that sounds unlikely.