CANE SUGAR. 



is here materially increased ; on the other hand the curve of large rollers being 

 flatter, cane is a longer time in contact and under pressure, and the rollers 

 being further apart there is less risk of re-absorption, but at the same time, 

 owing to the flatter curve, juice flows from the rollers less easily. A very 

 favourite size in recently erected plants is a roller 78 in. X 36 in., experience 

 having apparently shown that increase in diameter above this size is not 

 attended by better results. When not increasing the diameter in proportion 

 to length, the diameter of the gudgeons, and consequently their strength, 

 does not increase in proportion to horse-power transmitted. A roller of such 

 dimensions must essentially have its shaft made of the very best material ; 

 such a proportion with inferior material would only result in inferior work or 

 in breakages. 



Preparation of Cane for Milling. In the great majority of 

 modern mills the canes are subjected to a preparatory treatment before they 

 enter the mill proper ; the increased use of these appliances has been the 

 outcome of various causes. In the first place it has been found that, by a 

 preparatory treatment, the capacity of a milling plant is greatly increased, 

 without any detriment to the quality of the work. Secondly, the use of 

 unloading machines gives a mass of material much more uneven than that 

 obtained by hand loading, so that the mill will often refuse the feed. The 

 devices used in the preparatory treatment of the cane do not so much extract 

 juice as that they level the mass of cane, and prepare it for the milling process 

 proper. Thirdly, the replacement of the older varieties of cane by others, 

 notably by certain seedlings, has resulted in the handling of a brittle 

 material, which in many cases almost refuses to pass between the rollers of 

 an ordinary mill without previous partial treatment. 



The appliances used may be classed under three heads, crushers, 

 shredders, and revolving knives. Of the first, the Krajewski crusher, 

 Figs. 119 and 120, has been largely erected ; it consists of two superimposed 

 rollers ; each roller is grooved at equal distance over its surface in such a 

 way that the grooves form a succession of V shaped teeth, the teeth in one 

 roller being opposite the recesses in the other. The rollers in this appliance 

 can be placed at varying distances, so as either to crush the cane or even cut it 

 into pieces of about four inches in length. The crusher is made to be worked 

 off its own motor, or it may be driven ofi the main mill gearing. With 

 mill rollers of 34 in. in diameter, it is customary to have the crusher 

 rollers of about 26 in. in diameter, and to run them at a higher speed than the 

 mill rollers, a peripheral speed in the crusher rollers of 28 to 30 ft. per minute 

 being usual. 



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