CENTRIFUGAL SEPARATION 79 



The assertion of some authors that the relative amount of 

 skim milk and cream depends in part on the size of the outlets 

 is erroneous, inasmuch as experimental results by Ecles 1 and 

 Wayman conclusively show that, when the separator is run nor- 

 mally, the volume of the skim milk discharge is not more than 

 half of the capacity of the skim milk outlet. 



In order to secure any cream discharge, the cream outlet 

 must be located slightly nearer the axis of the bowl than the 

 outer wall of the skim milk tube. The more nearly alike the 

 distance of the two from the center, the more cream and the 

 less skim milk will there be. The greater the difference between 

 their distance from the center, the less cream and the more skim 

 milk will be discharged. Therefore, the turning of the cream 

 screw toward the center decreases the cream discharge and in- 

 creases the skim milk discharge and the turning of the cream 

 screw from the center increases the cream discharge and de- 

 creases the skim milk discharge. 



Simultaneously, with the turning of the cream screw to- 

 ward the center and thereby decreasing the amount of cream, 

 a richer cream is discharged, because the richest cream is nearest 

 the center of the bowl. The turning out of the cream screw, 

 while increasing the proportionate amount of cream, decreases 

 its richness, because the cream layer farther from the center is 

 thinner. 



Supply Tank, Float and Discharge Pans. As accessories to 

 the bowl may be considered also the milk supply tank, the re- 

 ceiving cup with float and the milk and cream discharge pans. 



The milk supply tank rests on an extension of the separator 

 frame. It is used only in the case of hand separators. In factory 

 machines the milk runs into the separator direct from the vat or 

 heater. The receiving cup is a part of the cover of the discharge 

 pans. It accommodates the float, which device consists usually of 

 a sealed, hollow tin bob acting as a regulator of the milk inflow. 

 When the separator is fed too fast it rises on the surface of the 

 milk in the receiving cup and closes a part of milk outlet of the 

 supply tank. 



1 Eckles and Wayman. Factors Affecting the Per Cent Fat in Cream from 

 Farm Separators. Missouri Bulletin No. 94, 1911. 



