VARIATKJX OF FAT IN CREAM 



87 



curate testing when the separator float is a conspicuous part of 

 the scrap pile on the farm . 



4. Effect of Speed of Machine on Richness of Cream. —'I he 

 speed of the revolving bowl produces the force — centrifugal force 

 which dri\-es the skim-milk out of the bowl. The greater the 

 speed, the greater the centrifugal force and the more rapidh" 

 the skim-milk lea\'es the bowl. An increase in the speed, there- 

 fore, forces more skim-milk through the ■ skim-milk outlet. 

 This means less milk for the cream outlet and consequently 



EFFECT OF SPEED UPON THE RICHNESS OF CREAM 



NORMAL SPEED 



LOW SPEED 



HIGH SPEED 



100 LBS. OF 4.4,V' MILK 100 LBS. OF 4.4^ MILK 100 LBS. OF 4.4 t MILK 



CREAM CONTAINS 4.4 LBS. FAT CREAM CONTAINS 2.-1 LBS. FAT CREAM CONTAINS 44 LBS. FAT 



U.B.C.V 



90 LBS. 

 SKIM-MILK 



TEST OF CREAM =44^ 



81 LBS. 

 SKIM-MILK 



TEST OF CREAM zz I 1 



TEST OF CREAM =63> 

 ■Li. 100 =63^ 



Fig. 16. 



richer cream. A decrease in the speed forces less skim-milk 

 through the skim-milk outlet, more milk has to be discharged 

 through the cream outlet and the cream, therefore, is thinner. 



These facts were established experimentally. A separator 

 was so adjusted that, when run at normal speed f6o turns of 

 crank per minute), it delivered oo pounds of skim-milk and lo 

 pounds of cream. When the speed was lowered to 25 turns of the 

 crank per minute, the skim-milk outlet discharged only Si pounds 

 of skim-milk, increasing the amount of cream deli\'ered to 19 

 pounds. When the speed was raised to 75 revolutions per 

 minute, the skim-milk discharge increased to 93 pounds, reducing 



