170 



CONTINUOUS PROCESS EVAPORATORS 



milk in the tubes (100 feet per second or more) increases the 

 capacity of the heating- surface, and the small amount of milk 

 in circulation, together with the low level of the milk in the 

 tubes, reduces the possibility of foaming, confining; the foam to 

 and breaking it up in the upper part of the tubes where film 

 evaporation takes place. 



The escape of the condensed milk is continuous and the 



COHMMSATION OVTLST 



Pig 1 . 74. Cross section of Buflovak rapid circulation evaporator 



Courtesy of Buffalo Foundry and Machine Co. 



degree of concentration is controlled by a valve regulating the 

 outlet. The condensed milk runs by gravity from, the steam 

 chest into a reservoir located under the evaporator. In this case 

 the reservoir must be under the same vacuum as the evaporator. 

 In some cases it is recommended to have an intermediate storage 

 tank removing; the condensed milk from the evaporator by a spe- 

 cially constructed steam pump. 



