CONDITIONS AFFECTING RICHNESS OF 



107 



centrifugal force, retards the escape of the skim milk, reduces 

 the capacity of the skim milk outlet and more milk has to be 

 discharged through the cream outlet. The cream, therefore, is 

 thinner. In the following table are summarized results of ex- 

 periments 1 showing the effect of the speed of the separator on 

 the richness of the cream. 



Table 13. Effect of Speed of Separator on Richness of Cream. 



Low Speed 



Normal Speed 



High Speed 



These facts apply with all separators and under all con- 

 ditions where the skim milk and cream exits are so adjusted 

 that the skim milk outlet is farther from; the center of the bowl 

 than the cream outlet. This is the case with most separators 

 and under most conditions. 



Additional factors which may enter into the causes of richer 

 cream, as the result of higher speed, are the reduced relative 

 friction in the skim milk outlet, due to the larger volume of skim 

 milk discharged and the increased relative friction in the cream 

 outlet due to the greater viscosity of the richer cream. Further- 

 more, the more complete separation in the case of high speed 

 may in part at least be conducive of richer cream. 



1 Hunziker. Why Cream Tests Vary. Purdue Bulletin No. 150, 1911. 



