332 



CHAPTER XVIII 



For concentrating 130 tons of juice from 13 to 65 Brix there are to be 

 65 - 13 



removed 130 X 



104 tons of water, which in quadruple effect will 



require 26 o steam per cent, on cane. 



If the whole evaporation of water in graining be considered as equivalent 

 to a concentration to 96 Brix, in one operation the water removed is 



130 X - 7 - 104 = 8-4 tons, to which is to be added 2 tons water 

 90 



as representing washings from tanks, at centrifugals, dilution of molasses, 

 and water surreptitiously introduced into the pan. The consumption of 



steam is then ~ =12-2 steam per cent, cane, to which is added 0-3 

 0-05 



steam per cent, on cane for heating of syrup and molasses, making the total 

 consumption at this station 12-5 per cent, on cane. 



The loss in steam pipes, leaky traps, etc., is taken as 0-5 steam per cent. 

 on cane. 



For concentration to other degrees Brix and for effects of 3, 4, and 5 cells, 

 results of the computation made as above are as below. 



CONSUMPTION OF STEAM PER CENT. ON CANE UNDER DIFFERENT CONDITIONS. 



The above tabulation may be used as a basis of computing the steam 

 consumption in those installations which either use a pre-evaporator or 

 separate steam from a cell of the evaporator proper. Some examples are 

 given below, all referred to syrup at 65 Brix, the constant, 

 35-3 = 4,1 + 15-4 + 2-8 + 12-5 + 0-5, 



which appears in all the examples, being the value of in the general 

 equation developed above (p. 329). 



1. Quadruple effect, syrup at 65 Brix, first heating of juice by steam 

 separated from first cell. 



Consumption of steam is, - + 35-3 = 57 -4 per cent, on cane. 



2. Quadruple effect, syrup at 65 Brix, first heating of juice by steam 

 separated from second cell, reheating and graining by steam from first cell. 



, 104 (2 X 15 4) 12 5 2 8 , 

 Consumption of steam is - - + 35 3 = 49 8 



per cent, on cane. 



3. Quintuple effect, syrup at 65 Brix, first heating of juice by steam 

 separated from second cell, reheating and graining by steam from first cell. 



