Answer to Question #93138 in Chemical Engineering for Nduduzo

Question

If 36 000 kg of full cream milk containing 4% fat is to be seperated in a 6 hour period into skim milk with 0.45% fat, what are the flow rates of the two output streams from a continuous centrifuge which accomplishes this seperation? (Start by drawing a flow diagram of the process).

Answer 1

Total mass= 36000 / 6 = 6000 kg

Fat = 6000 x 0.04 = 240 kg

6000 - 240 = 5760 kg water.

Let the mass of cream be x kg then its total fat content is 0.45x. The mass of skim milk is (6000 - x) 

and its total fat content is 0.0045(6000 - x).

6000 x 0.04 = 0.0045 (6000 - x) + 0.45x

x= 478.1144 kg

So that the flow of cream is 478.1144 kg h-1 and skim milk (6000 - 478.1144) = 5521.8856 kg h-1