172 



CONTINUOUS PROCKSS EVAPORATORS 



of the concentrator and carries a pulley back of the rear head, 

 to which the power is transmitted. 



The rear of the concentrator terminates in the exhaust 

 chamber of the condensed milk vapors, which escape through a 

 galvanized iron flue to the outside. The vapors are not con- 

 densed by water, but escape into the atmosphere. The rear wall 

 is equipped with the intake of the fluid milk. In order to permit 

 the milk to feed the concentrator by gravity, without necessitat- 

 ing inconveniently high elevation of the forewarmer, the intake 

 is located at the bottom. 



In the front head, in close proximity to the periphery of the 

 concentrator is located the outlet of the condensed milk. Its 

 distance from the inside wall of the concentrator determines the 

 thickness of the film of condensed milk that is allowed to form 

 on the heating surface, and the amount of milk that is retained 

 in the concentrator. According to the amount of superheating 

 intended, this film may vary from -J to -1- inch in thickness and 

 the amount of milk retained in the machine may vary from 6 

 to 12 quarts. 



The front head is equipped with a cover which is fastened 

 to the rim with screw bolts and which carries a spy glass through 

 which the operator may watch the process. At the conclusion 

 of the operation this cover is removed and the dasher and blades 

 are taken out, so that both the shell and the dasher can be 

 readily washed. Over the top of the concentrator extends the 

 steam line, a 3 inch pipe, with H inch laterals, supplying the 

 steam jacket, and insuring uniform distribution of heat. The 

 steam line is also equipped with regulator and steam gauge. At 

 the bottom of the concentrator is located the exhaust and regu- 

 lating crip valve. 



The. continuous concentrator is constructed of diverse sizes 

 and capacities, the most common of these sizes are the following' : 



