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LABORATORY MANUAL 
EXERCISE NO. 8 
Object: To determine the capacity and efficiency of a centrifugal cream 
separator. 
Procedure: A cream separator is a delicate machine and should be given 
careful attention. The machine should be well oiled, better 
too much than not enough. A separator, damaged because of 
lack of oil, will never run the same again. The proper grade of 
oil should be selected. The bowl of a separator is its most im¬ 
portant part and should be treated as such. Immersing in 
boiling water or steaming after washing, and then placing out 
to dry will prevent rust. The bowl should not be rinsed before 
washing with scalding water since this tends to bake the albu¬ 
minoids on the bowl parts. The separator should be washed 
after every skimming. If the separator is not to be used for 
any length of time, all of the washable parts should be oiled to 
prevent rust. 
A. Every student should be assigned to a specific duty. Since 
there are 5 skimming exercises, the assignment allowing 5 to a 
separator may be as follows: 
(1) Foreman: Supervision of performance of experiment, as¬ 
sembling and operation of the separator. 
(2) Operator: Assembles bowl; oils machine; operates the ma¬ 
chine; dissembles machine, washes pails and utensils. 
(3) Assistant operator: Flushes the bowl, times the operation, 
pours in the milk; washes the machine. 
(4) Floor man: Obtains, weighs, and warms the milk; cleans 
floor; takes samples to tester. 
(5) Tester: Makes all tests necessary for the experiment. 
B. (1) Warm 20 pounds of milk to 90° F. 
(2) Assemble machine properly and operate at correct speed. 
(3) Flush bowl with one quart of luke warm water. 
(4) Turn on milk and take the time of skimming. 
(5) Flush the bowl at the end of the run. 
(6) Weigh the skimmilk and cream. 
(7) Test the skimmilk and cream. 
