19 



It is the practice in most modern factories to filter the sirup after 

 it comes from the evaporator, as more or less insoluble matter sepa- 

 rates from the juice during the process of evaporation. 



GRANULATION OF THE SIRUP. 



The filtered sirup is granulated in a vacuum apparatus which the 

 sugar maker calls a "strike-pan." The appearance of the granulat- 

 ing pan is shown on pi. 32 of the exhibit. 



The operation of the vacuum pan is one of several processes con- 

 ducted in the beet-sugar factory that requires a great amount of skill. 

 The pan is heated by several tiers of copper coils so connected that steam 

 can be admitted to any one of them at the will of the operator. Sirup is 

 drawn into the pan and concentrated until the pan is from one-fourth 

 to one-third filled with a liquid of such density that when a fresh 

 charge of cool sirup enters a large number of small crystals of sugar 

 is formed. 



The boiling is then continued in such a manner that these crystals 

 continue to grow in size until the entire pan is filled with a thick 

 mass of crystals of sugar and molasses. The number of crystals 

 formed at the beginning of the boiling determines the size of the 

 crystals, or the "grain" of the finished product. When the operation 

 is skillfully conducted no additional crystals, or "false grain," as it is 

 called, are allowed to form after the original quantity of "grain " which 

 the sugar boiler considers the proper amount has been formed. The 

 coarse and fine granulated sugars found in the market are due to the 

 manner is which the boiling is conducted and not to any subsequent 

 crushing or grinding operation. 



SEPARATION OF THE SUGAR FROM THE MOLASSES. 



The finished product of the vacuum pan is known in the sugar 

 house as "masse-cuite," and is separated into molasses and sugar by 

 means of centrifugal machines. These machines consist essentially 

 of a cylinder having walls of fine wire cloth and attached to a ver- 

 tical shaft in such a way that they can be made to revolve at a speed 

 of from 1,200 to 1,500 revolutions per minute. Small portions of the 

 "masse-cuite" are placed in these machines, which are then rotated at 

 the rapid rate named. The centrifugal force causes the molasses to 

 pass through the mass of sugar and the screen, while the crystals are 

 retained thereon. Any adhering molasses is removed from the crys- 

 tals of sugar by means of a spray of water to which a small portion of 

 ultramarine blue (a harmless coloring matter) is added to correct the 

 yellow r tint which the sugar would otherwise have. The construction 

 and outer appearance of the centrifugal machines may be seen by 

 inspecting the photographs on pi. 33 of the exhibit. 



DRYING AND PACKING THE SUGAR. 



The sugar as it comes from the centrifugal machine is moist and 

 must first be passed through the "graiiulator" before it is ready for 



