Question

The diameters of a large and a small vessel are 1.62 m and 16.2 cm, respectively. The vessels are
geometrically similar and operated under similar volumetric agitated power input. The mixing time
in the small vessel was found to be 15 s. Determine the mixing time (in seconds) in the large vessel.
(A) 15 (B) 30 (C) 61 (D) 122

Answer 1

t2

=

D2

1 / 6

N1

2 / 3

t1 D1 N2

Now ,

P1

=

P2

V1 V2

⇒ N13 D12 = N23 D22

∴

N1

=

D2

2 / 3

N2 D1

= 4.6415

∴ t2 = (4.6415)2 / 3 ≈ 61