Question

How does impeller speed affect bubble size?

(a) As impeller speed increases, the bubble size increases

(b) As impeller speed increases, bubble size stays consistent

(c) As impeller speed increases, bubble size becomes inconsistent

(d) As impeller speed increases, the bubble size decreases

I have been asked this question during an internship interview.

Enquiry is from Antibiotics topic in division Antibiotics & Enzyme Immobilization of Drug Biotechnology

Answer 1

The correct choice is (d) As impeller speed increases, the bubble size decreases

To explain: As impeller speed increases shear and turbulence increases, this decreases the bubble size. Large bubbles impedes in proper mixing of media. But smaller bubbles will give better mass transfer.