MANUFACTURE OF MILK POWDER 299 



being discharged into the cyclonic current at the center, carries 

 its maximum moisture content at that point, gradually surrenders 

 it to the air, as it moves outwiard to the periphery of the cyclonuT 

 current. The completion of the drying is accomplished in the 

 zones of incoming heated air which carry the least humidity. 

 Therefore, as the outwardly moving particles of milk surrender 

 more and more of their moisture, they pass through dryer zones 

 of heated air. This obviously both accelerates the speed of 

 drying and enhances the completeness of the removal of moisture. 



4. Inasmuch as the danger of the solubility-destroying effect 

 of heat is greatest while the milk is still in the liquid state, and 

 this effect is practically completely absent in milk from which 

 the bulk of moisture has been removed, this process has the ad- 

 ditional advantage of maximum preservation of the solubility 

 in the finished product. The temperature of the cyclonic air 

 current is lowest when it reaches the center where the moisture 

 content of the milk is greatest. By the time the particles of milk 

 come in contact with the hottest air (at the periphery) their 

 moisture content is lowest. 



5. This process tends to facilitate maximum recovery of 

 the milk powder. The moisture-laden air escapes in the center, 

 where the particles of milk are heaviest, and where their greater 

 specific gravity causes them to partake of the centrifugal motion 

 moving them outward until when completely dried, they strike 

 the steeply tapered confining walls of the drying chamber and 

 fall to the bottom of this chamber. 



Gray patent No. 1,157,935 involves, in addition to the new 

 and advantageous features established under patent No. 1.107,784. 

 and explained above, apparatus and a method for supporting the 

 milk or other substance to be desiccated on and by the introduc- 

 tion of a solid, sheet-like, or finely divided substance. In the 

 case of milk, the supporting or absorbing material used may be 

 previously desiccated milk. 



The desiccating chamber A described in this patent is similar 

 to the desiccating chamber shown under patent No. 1,107,784, 

 and the intake of the heated air B and discharge of the moisture- 

 laden air C are unchanged. The intake of the milk and support- 

 ing material into the desiccating chamber is located in the center 



