Coulson Centrifugation

Question 1

A cyclone separator, 0.3 m in diameter and 1.2 m long, has a circular inlet 75 mm in diameter and
an outlet of the same size. If the gas enters at a velocity of 1.5 m/s, at what particle size will the
theoretical cut occur?
The viscosity of air is 0.018 mN s/m2, the density of air is 1.3 kg/m3 and the density of the
particles is 2700 kg/m3.

Answer 1

2.17 × 10−6 m or 2.17 μm

Question 2

If a centrifuge is 0.9 m diameter and rotates at 20 Hz, at what speed should a laboratory centrifuge of 150 mm diameter be run if it is to duplicate the performance of the large unit?

Answer 2

speed of rotation = 49 Hz (2940 rpm)

Question 3

A centrifuge with a phosphor bronze basket, 380 mm in diameter, is to be run at 67 Hz with a 75 mm layer of liquid of density 1200 kg/m3 in the basket. What thickness of walls are required in the basket? The density of phosphor bronze is 8900 kg/m3 and the maximum safe stress for phosphor bronze is 87.6 MN/m2.

Answer 3

t = 1.51 × 102 m or 15.1 mm