Question

Which of the following is the slowest step in mixing process?

(a) Distribution

(b) Diffusion

(c) Dispersion

(d) Decomposition

This question was addressed to me in an online interview.

My doubt stems from Mixing in chapter Fluid Flow and Mixing of Bioprocess Engineering

Answer 1

Right choice is (a) Distribution

The explanation is: Distribution is an important process in mixing, but can be relatively slow. In large tanks, the size of the circulation paths is also large and the time taken to traverse them is long; this, together with the regularity of fluid pumping at the impeller, inhibits rapid mixing. Accordingly, distribution is often the slowest step in the mixing process.