Fundamentals of Particle Technology

Fundamentals of Particle Technology - support pages

Chapter 8

Centrifugal separation
Animated GIF of critical trajectory within a sedimenting centrifuge
Presentation of filtering centrifuge theory in Powerpoint conversion
On-line example of filter centrifuge design
Links - links

Answers to problems:
Q1
i) the correct answer is (c)
ii) the correct answer is (a)
iii) As the acceleration depends on the radial position. In gravity, the acceleration (9.8 m s-2) does not depend on the particles position. However, in a centrifuge position is important - see equation (a) above. So, the acceleration increases as the radial position increases. In order to relate position and time we will, therefore, need to integrate this equation - unlike under gravity settling.
iv) the correct answer is (c)
v) In order to appreciate in which direction the oil drops move, you must think about what would happen under gravity if the drops were within a column of liquid. As they have a density less than water, they will therefore float. Similarly, within a centrifuge surrounded by water - the oil drops will move INWARDS.
the correct answer is (b)
vi) the correct answer is (a).

Q2
i) the correct answer is (b).
ii) the correct answer is (d).
iii) the correct answer is (d).
iv) the correct answer is (a).

Q3
i) the correct answer is (a).
ii) the correct answer is (a).
iii) the correct answer is (c).
iv) the correct answer is (a).

Q4
Remembering that Sigma refers to the plan area of a settling basin that does the same clarification job, see the bottom of page 78, then assuming that there are no other factors different between these machines the answer will be the machine with the highest Sigma value.

Q5
Click here for an answer.

Q8
i) the correct answer is (d).
ii) the correct answer is (b).
iii) the correct answer is (c).
iv) the correct answer is (b).
v) the correct answer is (a).
vi) the correct answer is (b).
vii) the correct answer is (a).

Q9
i) the correct answer is (b).

FAQ

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