58 CREAMERY BUTTER MAKING 



but the cream thus gathered is largely the product of 

 the cream separator, only a small portion being still 

 creamed by the gravity process. The discussion on 

 creaming will therefore be confined to the centrifugal 

 process. 



CREAM SEPARATORS. 



History. The cream separator had its beginning in 

 1864 when Prandtl, of Munich, creamed milk by means 

 of two cylindrical buckets revolving upon a spindle. In 

 1874 Lefeldt constructed a separator with a revolving 

 drum similar to the later hollow bowl separators. This 

 drum had a speed of 800 revolutions per minute. But 

 it lacked an arrangement permitting a continuous 

 discharge of cream and skim-milk, so that the separator 

 had to be stopped at regular intervals when the cream 

 was skimmed off, the skim-milk removed, and the bowl 

 refilled for the next separation. 



It was not until 1879 that real separators appeared 

 upon the market. During this year two machines were 

 perfected which permitted continuous cream and skim- 

 milk discharges. One was known as the Danish Weston, 

 invented in Denmark, the other the De Laval, invented in 

 Sweden. Both of these separators were hollow bowl 

 machines. 



Other separators soon followed but no decided improve- 

 ment was made until 1891, when the De Laval separator 

 appeared with a series of discs inside the bowl which 

 had the effect of separating the milk in thin layers, thus 

 increasing both the efficiency and the capacity of the 

 separator. Since then various bowl devices have been 

 invented by numerous separator manufacturers. 



