Condensed Milk and Milk Powder 



185 



low temperature, although the film of drying milk is naturally ex- 

 posed for a brief time to the direct heat of the cylinder. The 

 cylinder revolves at the rate of about one revolution per minute, 

 the film of dried milk is scraped off the cylinder by a stationary, 

 adjustable knife and the desiccated milk discharged into a receiver. 

 The fresh milk enters the vacuum chamber at the bottom and the 

 revolving cylinder is so adjusted that it automatically picks up a 

 thin film of milk. This process was invented by Dr. Martin Ecken- 

 burg, of Sweden. 



Fig. 56. The Eckenburg milk drier 



A similar apparatus and process was invented and patented by 

 Emil Passburg of Berlin, Germany. This inventor recommends 

 the evaporation of the milk in the vacuum pan to about one-fourth 

 its volume before it enters the dryer. The dryer has a similar ar- 

 rangement as that of Eckenburg but is equipped with an additional 

 device for the purpose of insuring a film of uniform thickness of 

 the condensed milk. In some of these dryers the milk is sprayed 

 against the drum and a properly set knife regulates the thickness of 

 the film. The fact that the milk is partly condensed before reaching 

 the drum, greatly hastens the process of drying and increases the 



