332 CHAPTER XVIII 



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

 65 - 13 



removed 130 X 



65 



= 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 



joQ X - — — — - — 104 ==8-4 tons, to which is to be added 2 tons water 

 96 



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



and water surreptitiously introduced into the pan. The consumption of 



— 12-2 steam per cent, cane, to which is added 0-3 



steam is then 



0-85 



steam per cent, on cane for heating of s3Tup 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. 



104 — 15*4 



Consumption of steam is, — ^^—^ + 35 "3 = 57' 4 per cent, on cane. 



4 



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

 separated from second cell, reheating and graining bj' steam from first cell. 



. 104 — (2 X 15-4) — 12-5 -2' 



+ 35' 



49-i 



Consumption of steam is 



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. 



