Question

Please choose the correct option.
A. Axial mixing and radial mixing are aided by baffles.
B. Mixing efficiency is decreased due to baffles.
C. Power consumption rises due to baffles.
D. Vortex formation is reduced due to baffles.
Choose the correct answer from the options given below:

• A. A and B Only
• B. B and D Only
• C. A, C and D Only
• D. B, C and D Only

Hint:

Baffles represent a classic engineering trade-off: You pay more in energy (higher power consumption) to get a much better result (uniform mixing and no vortex).

Answer 1

The Correct Option is C

Concept: Baffles are stationary plates added to agitated vessels to alter the flow patterns generated by the impeller, primarily to eliminate the central vortex and improve homogenization.

Step 1: Analyze the physical impact of baffles.

• Statement A: Correct. Baffles disrupt the tangential "swirl" and convert it into axial and radial flow, ensuring the entire tank is mixed.
• Statement B: Incorrect. Baffles are installed specifically to $increase$ mixing efficiency by preventing solid-body rotation.
• Statement C: Correct. Because baffles create resistance to the flow and increase turbulence, the motor must do more work, leading to higher power consumption.
• Statement D: Correct. Baffles disrupt the circular motion that leads to a central vortex, thereby eliminating or significantly reducing it.

Step 2: Final Selection.
Statements A, C, and D are correct, while B is false.