Question

The rate of mixing in an equipment can be explained by:

• A. Mixing index
• B. Uniformity index
• C. Power requirement
• D. Power index

Hint:

A Mixing Index of 1 indicates a perfectly random mixture. If the index is very low, it means the components are still separated into distinct clusters.

Answer 1

The Correct Option is A

Concept: Mixing is a unit operation intended to reduce the non-uniformity of a system.

• Efficiency is measured by how close the mixture is to a random distribution.

• The progress of mixing over time is quantified using specific coefficients.

Step 1: Defining the Mixing Index.
The mixing index is a dimensionless number that describes the degree of mixing achieved. It compares the observed standard deviation of samples to the theoretical random deviation.

Step 2: The role of the index in rate calculation.
As time increases, the mixing index approaches a constant value (usually 1). The speed at which it approaches this value defines the rate of mixing.

Step 3: Distinguishing other indices.
Power indices relate to the energy consumed, not the quality or rate of the blend. Therefore, the Mixing Index is the primary descriptor for mixing performance. Final Answer: (A)