CONTINUOUS PROCESS EVAPORATORS 171 



THE CONTINUOUS CONCENTRATOR. 



The inflow of the fluid milk and the outflow of the_on- 

 densed milk are continuous. The milk is condensed under atmos- 

 pheric pressure at 212 degrees F. A rapidly revolving" agitator 

 throws the milk in a thin film against the steam-heated and con- 

 tinuously polished periphery of a. jacketed copper drum. By 

 keeping the heating surface clean and bright, and the milk 

 rapidly moving, the power of the milk to absorb and utilize heat 

 is greatly augmented and the rapidity of evaporation increased. 



Description of Continuous Concentrator. The continuous 

 concentrator consists of a hollow copper drum. The copper shell 

 is surrounded by a steam jacket which is insulated. The space 



Fig. 75. The continuous concentrator with preheater and cooler 



Courtesy of Creamery Package Mfg. Co. 



between inner shell and jacket is about one inch. 



This drum carries in its interior, a revolving dasher with 

 ffHir or more blades, according to the size of the machine, and 

 similar to an ice cream freezer or a flash pasteurizer. The edge 

 of these blades comes in direct contact with the inner surface 

 of the shell which is the heating surface, so that when revolving, 

 each blade constantly removes from the heating" surface any 

 milk that adheres to it. 



The blades are pressed against the heating surface by the 

 centrifugal force that is generated when the machine is in mo- 

 lion. The arms to wjiich the blades are attached are equipped 

 witli stops that control their pressure against the heating sur- 

 face so as to insure continuous and uniform pressure. The shaft 

 which carries the dasher passes through the front and rear heads 



