Condensed Miek and Milk Powder 45 



heater. In this case it is advisable to set a wire mesh strainer (sixty 

 to eighty meshes to the inch) over the sugar well. The sugar is 

 placed into this strainer, a little at a time ; the hot milk from the 

 heater passing into and through the strainer dissolves the sugar. 

 A paddle or stick should be used to stir the sugar in the strainer. 

 For greater convenience and economy of labor, the sugar barrels 

 and scales are placed on the floor over the well room. The sugar 

 is transferred to the strainer below through a sugar chute which 

 may be equipped at the lower end with an adjustable cut-off, to reg- 

 ulate the sugar coming down. Other factories dissolve their sugar 

 in boiling water in a separate tank, and draw this syrup into the 

 vacuum pan together with the hot milk. This is a very commend- 

 able practice as it minimizes the danger of undissolved sugar crys- 

 tals to escape into the pan. Moreover, this watery syrup can be 

 boiled without danger of giving the milk a cooked flavor. 



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 room itself, in which case it is 

 elevated above the floor six to eight feet. The vacuum pan is con- 

 nected with the vacuum pump which should be installed near the pan. 



Description of the Vacuum Pan. — The vacuum pan is a retort 

 in which the milk is heated and evaporated in partial vacuum. The 

 origin of the term "pan" has not been satisfactorily explained. In 

 the early and experimental days of the manufacture 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 constructed of copper, iron, steel or 

 bronze. Practically all of the vacuum pans used for condensing milk 

 are made of copper throughout ; they are of various styles and sizes. 

 The predominating size used in milk condenseries is the "six-foot 

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

 feet in diameter. 



