Question

The sequence of multiple-effect evaporation for concentrating liquid foods:
A. Feed enters first effect at boiling temperature
B. Vapour from the first effect heats second effect
C. Concentrated product exits last effect
D. Vacuum applied increasingly in later effects
E. Steam supplied to first effect only
Choose the correct answer from the options given below:

• A. A, E, B, D, C
• B. A, E, D, B, C
• C. A, B, E, D, C
• D. E, D, C, B, A

Hint:

Multiple-effect evaporation: reuse vapor → save energy.

Answer 1

The Correct Option is B

Concept: Multiple-effect evaporation improves energy efficiency by reusing vapor generated in one effect to heat the next.

Step 1: Feed entry (A).
Liquid feed:
• Enters first effect
• Is heated to boiling

Step 2: Steam supply (E).
External steam:
• Is supplied only to first effect

Step 3: Pressure arrangement (D).
Each subsequent effect:
• Operates at lower pressure
• Enables boiling at lower temperature

Step 4: Vapor utilization (B).
Vapor from first effect:
• Acts as heating medium for second effect

Step 5: Product removal (C).
Final concentrated product:
• Leaves from last effect

Step 6: Final sequence. \[ A \rightarrow E \rightarrow D \rightarrow B \rightarrow C \] Final Conclusion:
Option (2) is correct.