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CHAPTER XII 



1. Faulty design, especially in the earlier plants, and particularly in 

 connection with the cane cutting machinery. 



2. Difficulty in maintaining a continuous supply of cane, an essential to 

 the economic conduct of the process. In the beet sugar industry the raw 

 material may be stored over long periods, a proceeding impossible with 

 the cane ; and again the more highly developed social organization in beet 

 growing districts, as opposed to the pioneer conditions in cane countries, 

 tends to more regular working. 



3. Greater elasticity of the milling process, whereas the diffusion scheme 

 has to be operated at its designed capacity, or else at a loss of sugar or at 

 an extreme dilution. In the case of poor cane in the milling process, all 

 dilution can be stopped, while in diffusion dilution must always obtain. 



4. Excessive fuel accounts, due however not so much to inherent faults 

 in the process, but rather to the undeveloped state of steam utilization 



schemes at the time when the diffusion 

 processes were installed. 



Diffusion Apparatus. The apparatus 

 peculiar to a diffusion plant are the vessels 

 in which the diffusion takes place, and the 

 devices used to cut the cane into slices 

 or chips. 



Cane Cutter. A type of cane cutter 

 that has been largely used is shown in 

 vertical section in Fig. 150 ; on a vertical 

 spindle b, belt-driven from the pulley d, by 

 means of the bevel wheels c, is carried a 

 disc e. The whole is enclosed in a sheet 

 iron casing h and closed by a strong cover 

 g ; fastened on to the disc e are a number 

 of boxes varying from six to twelve, each 

 of which carries a strong sharp knife. The 

 knives are fixed on the disc exactly similar 

 to the cutting edge of a carpenter's plane, 

 and the knife boxes are arranged so that 

 they may readily be removed from the disc 

 and spare knives substituted when one set has become blunted. A plan 

 of the disc with an arrangement of twelve knives is shown in Fig. 151. 

 Securely fixed to the cover are one, two or more hoppers a into which 

 are fed the canes, which descend on to the disc by their own weight. A 

 high speed is given to the disc, from 100 to 150 revolutions per minute, 

 and the knives cut the cane into chips one-twentieth of an inch or more 

 in thickness, dependent on the setting of the knives. The hoppers are 

 made either vertical or at an angle the former giving round and the latter 

 oval chips. The chips fall into the receptacle formed by the sides of 

 the apparatus below the disc, and thence pass on to the shoot. The cutter 

 is variably placed above or below the diffusion battery. Cane cutters of this 

 type differ in details. They are sometimes directly driven without the 

 interposition of belt gearing, and are sometimes over instead of under-driven 

 as shown in Fig. 150. The shoot i is also sometimes dispensed with and its 

 place taken by a scraper actuated by the shaft b. In this case the bottom of 



FIG. 150 



