Question

If the Hausner’s ratio is between 1.50 to 1.61, then the powders exhibit

• A. Very poor flow
• B. Fair passable flow
• C. Excellent flow
• D. Very very poor flow

Hint:

Hausner's ratio is used to predict the flow characteristics of powders. Ratios between 1.50 and 1.61 suggest fair passable flow.

Answer 1

The Correct Option is B

Step 1: Understanding Hausner's ratio.
Hausner’s ratio is an empirical number that measures the flowability of powders. It is calculated as: \[ \text{Hausner's ratio} = \frac{\text{Tapped density}}{\text{Bulk density}} \] A Hausner’s ratio between 1.50 and 1.61 indicates powders with fair passable flow, meaning the powders are somewhat cohesive but can still flow with moderate effort.
Step 2: Analyzing the options.
(1) Very poor flow: Incorrect, this range indicates fair passable flow, not very poor.
(2) Fair passable flow: Correct — This range of Hausner’s ratio corresponds to fair passable flow.
(3) Excellent flow: Incorrect, excellent flow is associated with a Hausner's ratio below 1.25.
(4) Very very poor flow: Incorrect, this is not accurate for the given Hausner’s ratio.
Step 3: Conclusion.
The correct answer is (2) Fair passable flow.

Answer 2

Hausner's ratio is used to classify how easily a powder flows, with different ranges corresponding to different flow descriptions. Let's check each option against the classification used in this question.

1. Very poor flow: This description is generally reserved for higher Hausner ratio ranges than 1.50-1.61 in the classification scheme being applied here, so it does not match this range.
2. Fair passable flow: In the classification used for this question, the Hausner ratio range of 1.50 to 1.61 corresponds to powders that flow with moderate difficulty, described as fair passable flow.
3. Excellent flow: Excellent flow is associated with Hausner ratios much closer to 1.0, reflecting free-flowing, minimally cohesive powders, which is far from the 1.50-1.61 range given here.
4. Very very poor flow: This description is applied to the highest Hausner ratio ranges, beyond the 1.50-1.61 window specified in this question.

Matching the given range to the classification scale used here points to fair passable flow.

Therefore, the correct answer is Fair passable flow.