MANUFACTURE OF MILK POWDER 297 



admitted near the bottom in the center of the drying chamber, 

 means for heating the air, blowing it into the drying chamtber 

 and screens located near the bottom at the periphery of the~ 

 chamber for discharging the spent air are provided. 



In this apparatus the sprayed milk falls from near the top 

 of the drying chamber through an ascending current of heated 

 air. The milk spray entering on all sides causes an even distribu- 

 tion of the spray particles and a consequent even deposit of the 

 dried milk particles on the bottom of the drying chamber. The 

 previously condensed milk is sprayed into the drying chamber 

 while heated to a temperature of 140 degrees P., the temperature 

 of the air in the drying chamber ranges from 180 to 200 degrees 

 F. The distance over which the spray falls through the ascend- 

 ing current of heated air being sufficient to permit the removal 

 from the milk particles of substantially all the remaining 

 moisture. 



The Gray Process. Chester Earl Gray of Eureka, Calif., 

 and Aage Jensen of Oakland, Calif.. U. S. patent No. 1,078,848, 

 November 18, 1913, Chester Earl Gray, Assignor of one-half to 

 Aage Jensen, U. S. patent No. 1,107,784, August 18, 1914, and 

 Chester Earl Gray, U. S. patent No. 1,157,935, October 26, 1915, 

 and U. S. patent No. 1,266,013, May 14, 1918, subjected the pos- 

 sibilities of spray drying to extensive study and invented and 

 patented successive improvements and new principles relating 

 to desiccation of milk and other liquid substances. 



Gray patent No. 1,107,784 involves an apparatus with a 

 circular desiccating chamber A, having a cone-shape lower sec- 

 tion B, terminating in a discharge opening for the dried sub- 

 stance, and a discharge opening C for the moisture-laden air. 

 The heated air is introduced into the desiccating chamber 

 peripherally in a tangential direction, by means of a blower D. 

 Between the blower and the drying chamber there is an inclosed 

 heating coil (steam coil) over and around which the air is blown 

 into the drying chamber. The tangential entry of the heated air 

 into the circular chamber sets up a cyclonic current therein and 

 this effect is augmented by introducing the air at several different 

 points through tangential openings a. The milk to be desiccated 

 enters under pressure through a spray nozzle H, located in the 



