CREAM SEPARATION 55 



whole milk are handled each day. As the dairy industry 

 grew, a greater need was felt for a more efficient method 

 of obtaining the milk-fat in the form of cream. The 

 result of this need was the discovery of a method of 

 separating the cream and milk-serum by centrifugal force. 

 Centrifugal force acts in direct proportion to the 

 weight of matter. The specific gravity of skimmed-milk 



Ipf 



FIG. 16. A comparison of the amount of butter lost in the skimmed- 

 milk from one cow producing 5000 pounds of milk in one year, by the 

 use of different methods of cream separation. Reading from left to 

 right: water-dilution method, 33 pounds; shallow-pan method, 22 

 pounds; deep-setting method, 8.5 pounds; centrifugal method, 1 

 pound. 



is greater than that of cream ; therefore the skimmed- 

 milk is thrown from the center with greater velocity 

 than the cream. This concentrates the cream toward 

 the center of the bowl. 



42. Intermittent separation. The first centrifugal 

 cream separator consisted of pails attached to cross-arms 

 which were probably three to six feet in length. The 

 pails were fastened in such a way that the heavier sub- 



