424 



CHAPTER XX 



Centrifugalling for White Sugars. — When plantation white sugars are 

 made, a more complete removal of the adhering molasses is necessary. This 

 is effected by washing with water and with steam. The water used should 

 be as pure as possible, and the condensed steam available in every factory 

 forms a suitable supply after cooling. Before the steam is allowed to act 



Fig. 267 



on the wall of sugar it should be freed from water by being passed through 

 a separator.'^.With high-grade massecuites the quantity of water used for 

 washing is about thirty lbs. in a 40-in. centrifugal, or i lb. to 10 lbs. of sugar. 

 The quantity of steam used is about i lb. to 5 lbs. of sugar. With lower 

 grade massecuites boiled from first molasses these quantities are doubled. 



/ 



Fig. 268 



When following this method the water and steam runnings are of very 

 high purity, and it is expedient to separate them from the first runnings 

 and to return them separately to the high-grade product. This process 

 is known as the classification of molasses, and the scheme was first suggested 

 by Perier in the European beet sugar industry in 1852. Donner's patent 



