CANE SUGAR. 



the degree Brix be 18 ; let the canes contain 12 per cent, of fibre and be dry 

 crushed to 45 per cent, of fibre, after which with complete admixture water 

 20 per cent, on cane is added, and the saturated megass crushed to 50 per cent, 

 of fibre. In a dry crushing following on the equations already established 

 there are obtained 73*33 parts of juice at 18 Brix per 100 cane; 14-67 parts 

 of juice are left in the megass, which, when completely mixed with 20 parts 

 of water, give 34-67 parts of diluted juice at 7*61 Brix ; on crushing this 

 megass to 50 per cent, of fibre there are obtained 22*67 parts of diluted juice 

 at 7-61 Brix; this, when mixed with 73-33 parts of normal juice at 18 Brix, 

 will give 96 parts of mixed juice at 15-55 Brix, and the dilution per cent, on 

 normal juice is by the usual method of calculation 15*75 per cent. ; the added 

 water per cent, on cane at the same time being 20 per cent. In Table II., at 

 at the end of this section, is calculated for single maceration and complete 

 admixture the dilution per cent, on normal juice when water 10 per cent. 

 to 50 per cent, is added to canes containing 12 per cent, of fibre and dry 

 crushed to 45 per cent, of fibre, and after saturation to 50 per cent, of fibre. 



Now if the admixture is incomplete, water passes into the mixed juice 

 without carrying in the sugar which it was the object of its application to 

 obtain, and the dilution will be higher than calculated above. Such a system 

 of comparison gives, then, an idea of the efficiency of the added water, and 

 may be used in the control or technical oversight of a mill, and it is to this 

 end that the calculation has been introduced. 



4. A Method for expressing the Efficiency of the Added Water. A control 

 or oversight of the useful effect of the added water is afforded, as has been 

 shown above, by comparison of the figures expressing the added water per 

 cent, on canes with the dilution per cent, on normal juice, and also by com- 

 paring the density of the last mill juice with the calculated figure when the 

 admixture is complete. A more exact and definite comparison may be 

 obtained by the use of the following methods : 



In a plant employing a single maceration process, let the canes contain 12 

 per cent, fibre, and let them be dry crushed to 45 per cent, of fibre ; then on 

 the lines already established, the extraction due to the dry crushing is 85*82 

 per cent. Let water 20 per cent, on cane be added to the dry crushed 

 megass ; then with complete admixture and crushing to 50 per cent, fibre, a 

 further extraction of 9-20 is obtained. Suppose the actually recorded extraction 

 is 93*63 per cent. ; then that due to the saturation is 93-63 85-82 = 7'81. 



1-1 .0 -I 



What may be termed the efficiency of the added water is then = *849 ; 



v' 20 



i.e., the added water has extracted 84*9 per cent, of the maximum amount of 

 sugar possible. To apply this formula in actual practice demands a knowledge 

 of the fibre in the diy crushed megass, a determination that is not usually 

 made ; perhaps in actual work it would be sufficient to determine the average 



506 



