🔍 Key Concepts

• Study the flow path of feedwater and vapors through the unit (follow the arrows and colors). • Identify what happens in section G compared with the area where device B is located. • Recall the difference between boiling/evaporation, condensation, and cooling in a distilling or evaporator unit.

💭 Think About

• Look at where device B is positioned: Is it in the path of hot vapor, incoming feedwater, or outgoing distillate? • Ask yourself what phase change (if any) is occurring at device B: is water turning to vapor, vapor turning to liquid, or liquid just being cooled? • Compare device B with any similar-looking bundle or coil elsewhere in the illustration—do they serve similar or opposite purposes?

✅ Before You Answer

• Verify which arrows (color and direction) pass through B and whether they represent vapors or liquid feedwater. • Confirm where the product from section G travels next and whether it makes contact with B. • Make sure your choice matches both the location and the temperature direction (heating vs cooling) suggested by the diagram.