MANUFACTURE OF MILK POWDER 



287 



at a temperature of about 100 degrees F. and that the milk at 

 no time reaches temperatures higher than 120 degrees F. 



The Covers Process. This process and equipment was 

 invented and patented by Francis X. Covers, of Owego, New 

 York, U. S. patent No. 939,495, November 9, 1909. 



In the Covers patent the milk is dried on two revolving, 

 hollow cylinders (5) located at such proximity to each other 



Pig-. 97. The Govers milk drier 



that there is practical contact at the periphery of the two cyl- 

 inders, in a similar manner as is the case with the Just process. 

 These revolving cylinders, however, are inclosed and operated 

 in an outer casing which serves as a vacuum chamber (2), which 

 connects with a vacuum pump through pipe (27). There is a milk 

 supply tank (1) with regulating valve (4), feeding the milk to 

 the vacuum chamber through pipe (3). Plates (10) which bear 

 against the opposite ends of the cylinders (5) form with the 

 revolving cylinders a receptacle (13) to receive and retain a 



