THE DIFFUSION PROCESS. 



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 inter- 

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

 as shown in Fig. 133. The shoot t is also sometimes dispensed with and its 

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

 the receptacle h is flat, or nearly so, and the chips are swept out through an 

 opening in the bottom. 



FIG. 134. 



To work up 300 tons of cane in twenty-four hours, a plant of this nature 

 will be about 5 ft. in diameter. The capacity depends on the number of 

 hoppers, and on the setting of the knives, whether to give thick or thin chips. 

 More cane can be cut when thick chips are allowed, but the efficiency of the 

 after process of diffusion is diminished. 



Diffusion Cell. A section through a cell of a diffusion battery, along 

 with its accompanying juice heater, is shown in Fig. 135. It consists of a 

 cylindrical vertical shell, the bottom being made with a slight slope, and the 

 top fitted with a head box ; the cell is closed by a door on the top, which is 

 clamped tight by the screw and lever shown at b ; by slackening the screw 

 the door can be slung on one side, to allow of a charge of chips being intro- 

 duced. Round the bottom part of the cell is fixed a perforated false bottom d r 



227 



