238 



MANUFACTURE OF MILK POWDER 



as it is scraped from the drum. This is separated from the large 

 vacuum chamber by a series of air locks, so that the material may be 

 removed without breaking the vacuum in the large chamber. 



The milk, as it enters the vacuum chamber, is sprayed into the 

 concave ends of the drum. In this manner it is fore-condensed. 

 It is then withdrawn from the vacuum chamber by a pump, and 



Fig. 60. The Ekenberg milk drier 



returned again, this time being sprayed upon the periphery of the 

 drum. The milk remains on the drum only long enough for it to 

 make three-quarters of a revolution. 



After the dried milk is removed from the exsiccator, it is placed 

 in a special drying chamber at a temperature of 90 degrees F. where 

 it remains long enough for the milk sugar to crystallize. This is 

 usually accomplished in about an hour. After this it is ground and 

 sifted in a similar manner as is the case in the milling of wheat flour. 



