68 SWEETENED CONDENSED MILK CONDENSING 



CHAPTER V. 

 CONDENSING. 



From the ground well in the well room the sweetened milk 

 is drawn into the vacuum pan, where it is condensed under 

 reduced pressure. The vacuum pan is usually located on the 

 second floor over the well room, or in the well itself, in which 

 case it is elevated above the floor six to eight feet. The vacuum 

 pan is connected with the vacuum pump, which should be in- 

 stalled near the pan. 



Description of the Vacuum Pan. 

 The vacuum pan is a retort in 

 which the milk is heated and evapo- 

 rated in partial vacuum. The origin 

 of the term "pan" has not been 

 satisfactorily explained. In the early 

 and experimental days of the manu- 

 facture of condensed milk, the milk 

 was evaporated in open kettles, 

 called pans. It is probable that the 

 name of this primitive apparatus 

 was passed on to the more perfected 

 machinery now in use. 



The vacuum pans are construct- 

 ed of copper, iron, steel or bronze 

 Practically all of the vacuum pans 

 Pig-. 15. used for condensing milk are made 



vacuum pan and condenser of copper throughout ; they are of 

 Courtesy of Groen Mfg. GO. various styles and sizes. The pre- 

 dominating size used in milk con- 



denseries is the "six-foot pan." By the term six-foot is meant a 

 retort measuring six feet in diameter. 



There are two general types of vacuum pans on the market ; 

 pans that are relatively wide in diameter and shallow in depth, 

 and pans of relatively narrow diameter and which have a deep 

 body. Both types are claimed, by their respective manufacturers, 

 to have special advantages, such as ease of operation, uniformity 

 of action, economy of fuel and of water, and rapidity of evapora- 



