Question

Fresh whole milk containing 3.5% fat was separated using a centrifuge into cream with 50% fat and skim milk with 0.4% fat what will be the proportion of skim milk to cream

Answer 1

For 1hour whole milk feed = (60,000 /6 )Kg=10,000Kg

So that the flow rate of whole milk feed = 10,000 kg/hr

Mass of whole milk=10,000 kg

Mass of cream = x kg Mass of skim milk=(1-x) Mass balance equation is Whole milk= skim milk + cream 10,000kg=skim milk + x kg So, skim milk = (10,000-x) kg Material balance on fat is 10,000kg×0.04 = (10,000-x)×0.004 + x On solving the above equation we get the value of x So, x=361.44 kg So that the flow rate of cream = x= 361.44kg/hr and mass of skim milk= (10,000-x)=(10,000-361.44)kg = 9,638.56 kg So that the flow rate of skim milk = 9,638.56 kg/hr. for checking

(Whole milk) flow rate = (skim milk + cream) flow rate

10,000 kg/hr = (9,638.56 + 361.44) kg/hr 10,000 kg/hr = 10,000 kg/hr Hence it is proved.