Fermentor hydrodynamics: What internal hardware is primarily used to suppress vortex formation and improve gas–liquid dispersion (aeration efficiency) in a stirred tank?

Introduction / Context:
Good mixing and gas dispersion are vital for oxygen transfer. Vortex formation wastes power and reduces mass transfer; proper internals prevent this and enhance performance.

Given Data / Assumptions:

• Standard baffled stirred tank reactor.
• Goal is to reduce swirling vortex and improve aeration.
• Gas is introduced via a sparger; agitation by an impeller.

Concept / Approach:
Baffles are vertical strips mounted on the vessel wall. They break tangential flow, reduce vortexing, and promote top-to-bottom circulation, which in turn improves bubble dispersion and oxygen transfer.

Step-by-Step Solution:

Verification / Alternative check:
Design handbooks recommend 4 baffles at about 1/10 vessel diameter for optimal performance.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming higher impeller speed alone will improve dispersion; without baffles, it worsens vortexing.

Final Answer:
Baffles.