520 



MILK 



According to Kilbourne, pasteurization can be carried on in 

 the vacuum pans which are used for- condensing milk. These 

 pans have a coil at the bottom through which live steam is passed 

 for the condensation of milk. For pasteurization, water of suit- 



Fig. 207. — A large capacity Reid positive pasteurizer with wood body. 



able temperature should be used in place of live steam. After 

 the milk has reached the proper temperature it can be held for a 

 suitable length of time in these pans. 



One kind of continuous holder, also known as a retarder 

 (Fig. 209), consists of a series of tanks, one lower than the pre- 



Fig. 208. — The one-piece all brazed coil. The braces are wrapped well around 

 the coil tubing and are pinned fast to the center shaft. 



vious one, which allows the milk to flow slowly through the 

 system. Another sort consists of large tubes which are made 

 continuous by being connected at both ends. The heated milk 

 enters from the top and is discharged through a pipe which con- 

 nects with the lowest tube, and rises above the highest one. By 



