CENTRIFUGAL SEPARATION 77 



of carrying the skim milk to near the center before it is per- 

 mitted to escape is to reduce the force with which it is discharged. 

 By passing toward the center the skim milk has to overcome the 

 centrifugal force. 



These skim milk outlet tubes are very small, curved and 

 difficult to thoroughly cleanse, which is an objectionable feature 

 from the sanitary point of view. In the latest improved models 

 of bowls these tubes have therefore been done away with. This 

 has been accomplished by covering the top-most of the internal 

 discs with a special closing disc, the lower edge of which extends 

 to near the wall of the bowl and the upper end of which forms 

 a sleeve extending up into the neck of the bowl cover. This 

 closing disc carries sufficient projections on its upper surface 

 to form a narrow space between it and the cover of the bowl. 

 The skim milk passes through this space in the form of a thin 

 layer and leaves the bowl through a small opening, the skim milk 

 outlet, located at the bottom of the neck of the bowl cover. In 

 some makes of separators the skim milk is discharged through 

 the bottom of the bowl. 



The Cream Outlet. The cream finds its exit from the bowl 

 at, or near the top of the bowl cover. Its entrance to the outlet 

 is located slightly nearer the center than the centermost part 

 of the skim milk outlet. In most separators the cream outlet, or 

 cream screw is adjustable. If the cream screw is located in the 

 top of the bowl cover, it usually carries an eccentric orifice 

 which is the cream outlet. This screw may be turned so as 

 to place the opening or cream outlet nearer to or farther from 

 the center. If the cream screw is located in the side of the bowl 

 neck, the distance from the center at which the cream escapes 

 from the bowl is regulated by turning this screw farther in or 

 out. In the case of 'some bowls the cream outlet is stationary 

 and the skim milk outlet is adjustable. 



Adjustment of Cream Screw to Regulate Proportion of 

 Skim Milk and Cream and to Control Richness of Cream. As 



previously stated, the milk in the revolving bowl is forced to 

 the side of the bowl, forming a vertical wall. The inner line 

 of the milk in the bowl and of the skim milk in the skim milk 

 tube, or skim milk space forms a straight vertical line. 



