94 



work. With a battery of sixteen cells I think the dilution could be 

 easily reduced to 30 per cent, and the extraction be satisfactory. 



COAL CONSUMED. 



The quantity of coal consumed depends first, on the efficiency of the 

 boilers and evaporators employed, second on the quality of the coal, and 

 third on the dilution of the juice. 



In beet-sugar factories the basis of computation is generally based on 

 the dilution arising from drawing 180 pounds of diffusion juice from each 

 100 pounds of beet cuttin gs. In respect of evaporation what is found to 

 be true of beet juices will also apply to cane juices of the same density. 



From the arrangement of the machinery at Magnolia it was found 

 impossible to measure the quantity of coal consumed by the diffusion 

 work. In the last run, when the milling work was over, the centrifu- 

 gals were run drying seconds and the vacuum pan boiling thirds during 

 the process of the work. 



In addition to this, a part of the steam used was furnished by the 

 bagasse boilers, using wood and coal as a fuel not an economical method 

 of making steam. 



As nearly as could be estimated, the quantity of coal required to make 

 a pound of sugar was 2 pounds. The actual quantity of coal which 

 would be required with the best boilers and evaporators may be found 

 by consulting Dr. Karl Stammer's latest edition of u Text-book of Sugar 

 Making," pages 873 ct seq. 



When 180 pounds juice are taken for each 100 pounds beets the con- 

 sumption of coal to reduce the juice to a sirup of 60 per cent, total 

 solids is as follows : 



Pounds. 



With double-effect pan 13. 5 



With triple-effect pan 9.10 



With quadruple-effect pan 6. 76 



To reduce the sirup to masse cuite requires 4.44 pounds. 

 We find, therefore, the following quantities of coal necessary for each 

 100 pounds raw material giving 180 pounds of juice : 



Pounds. 



For a double effect 17.94 



For a triple effect 13. 54 



For a quadruple effect 11.20 



If now we take the ordinary dilution for sugar-cane, the following 

 numbers are found : 



In evaporating 180 pounds of diffusion juice from 100 pounds cuttings 

 to 60 per cent, sirup 156 pounds of water, are evaporated. In evaporat- 

 ing 125 pounds of diffusion juice to same density, only 101 pounds of 

 water are driven off. To evaporate 156 pounds of water 13.26, 9.10, and 

 6.76 pounds of coal are used for double, triple, and quadruple effects, 

 respectively. For the same weight of cane chips, giving 125 pounds of 



