CANE SUGAR. 



Special Treatment of Low Massecuites. The time required 

 for a complete crystallization of low grade products may be shortened by dis- 

 tributing over the surface of the massecuites a quantity of sugar crystals 

 which are allowed to slowly fall through the massecuites ; the quantity of 

 crystals used is about 1 per cent, on the weight of the massecuite. 



Crystallization in motion on a new basis has been applied in recent years 

 to low massecuites by means of air injection ; compressed air is introduced 

 at the bottom of the tanks containing massecuite by means of a rubber hose. 

 The treatment is begun after the massecuites have stood for 48 hours ; at first 

 they are treated daily, then twice a day, and eventually every three hours. 



Calculation of Proportions of Syrup and of Molasses to 

 be used to obtain a Strike of prearranged Purity.- Let the 



volume of the whole strike be unity and that part due to the syrup be x. 

 Then 1 x is the volume due to the molasses. Let^? be the desired purity of 

 the strike andj9 8 and p m be the purities of the syrup and of the molasses. 



Then p =. p t x + p m (1x] ; whence x * _ P 



Example. It is desired to obtain a strike of 65 purity from syrup of 



80 purity and molasses of 45 purity. 



65 45 

 The volume of the strike due to syrup is then gQ ^ = '571. 



If the whole volume of the strike is 1000 cubic feet the pan will be filled 

 up to 571 cubic feet with syrup massecuite and the strike completed with 

 429 cubic feet of molasses. This calculation supposes that the percentage of 

 solids in the syrup massecuite before drawing over the molasses and in the 

 molasses are the same. 



Eifect of Size of Grain. The smaller the grain the larger is the 

 exposed surface and the greater the area of crystal surface that comes in 

 contact with the mother liquor within a given time ; hence the rate at which 

 the desaccharification of a mother liquor proceeds is greater in a small grained 

 massecuite than in one with larger crystals ; it is only however the time that 

 is affected, as the total amount of sugar that separates is solely determined by 

 the water content of the massecuite. In addition, with the larger exposed 

 area of crystal surface, there will be less chance of a deposit of fine or of false 

 grain, and for this reason a small grained massecuite can be safely cooled at a 

 greater rate than can a larger grained one. 



Rapidity of Cooling. The rate at which a body cools is within 

 certain limitations proportional to the excess temperature ; hence immediately 

 after striking the rate of cooling is greatest ; if the massecuite cools faster 

 than sugar can deposit, the coefficient of supersaturation increases, and there 

 is danger of the formation of fine grain due to the sudden deposit of crystals 

 from a very supersaturated solution, the sugar so depositing not forming on 



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