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 propttrtion to the 

 weight of matter. The specific gravity of skimmed-milk 





|\ 'a* 



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

 milk from one cow i>roducing 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 t)f cream ; therefore the skimmed- 

 milk is thrown from the center ^\•ith 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 hea^'ier sub- 



