MANUFACTURE OF MILK POWDER 239 



It is then ready for the market, which it reaches packed in either 

 tins, boxes, or barrels. 



The fact that the milk is evaporated under reduced pressure 

 makes it possible to accomplish the drying at a relatively low tem- 

 perature, although the film of drying milk is naturally exposed for 

 a very brief time to the direct heat of the drum, and which obviously 

 varies with the steam pressure in the drum. The manufacturers 

 claim that the drying of the milk takes place at a temperature of 

 about 100 degrees F. and that the milk at no time reaches tem- 

 peratures higher than 120 degrees F. . 



The Buflovak Process. The principle of drying milk and 

 other liquids on a steam- or hot water-heated revolving drum has 

 been put to extensive application through the activities of the 

 Buffalo Foundry & Machine Co., Buffalo, N. Y. This company 

 has, during the last decade, invented, constructed and perfected the 

 "Buflovak" vacuum drum drier. Patents were granted their engi- 

 neer, Mr. O. S. Sleeper, by the United States Government in 1911, 

 1913, 1914, 1915 and 1916. All these patents were assigned to the 

 Buffalo Foundry and Machine Co. 



These patents pertain to the drum drier as used for whole milk, 

 skim milk, buttermilk and milk products in general. They are 

 applicable to other products as well as to milk, but for milk they are 

 made specially accessible for cleaning and for sanitary control. 



The Buflovak drier consists of a casing in which revolves a 

 steam-heated, polished drum. The milk is fed to the surface or 

 periphery of this drum by a pan located beneath the drum and 

 placed lightly against the drum. The pan has an overflow along one 

 side for the automatic removal of the surplus milk not taken up by 

 the drum. To the bottom of this casing is supplied a quantity of 

 milk. This is pumped to the supply pan under the drum, the 

 overflowing milk running back into the lower portion of the casing. 

 There is slight pressure in the supply pan which causes the drum to 

 take up a heavy and even coating. Near the supply pan is installed 

 a leveling arrangement which levels off and equalizes the layer of 

 milk on the drum. As the drum revolves and the layer of milk 

 reaches what is termed the front of the machine it is continuously 

 removed in the form of a dry film by a stationary scraper. At this 

 point the machine is provided with a breaker which consists of a 

 shaft with a number of rods projecting through the same, which 



