CANE SUGAR. 



Perichon Process. 5 This method was originated at the Rodah fac- 

 tory of the Daira Sanieh in Egypt. The dry crushed megass is received in 

 trucks in which it is systematically diffused ; the trucks are mounted on 

 wheels and run on a tram line ; at the hottom of the trucks is a strainer and 

 discharge valve whereby the liquid contents of a truck can he drawn off, pumped 

 to an overhead tank, and transferred to the next truck in series. The time 

 allowed for diffusion in each operation is seven minutes. The weight of cane- 

 treated in 24 hours was 1000 tons, and the trucks used held about one and 

 three-quarter tons of megass and were of 90 hectolitres capacity (=316 c.ft); 

 the megass was diffused in all nine times, the drawn off liquor being about 6 

 to 8 Brix in density, and of purity but little less than that of the expressed 

 juice. After the final washing, the megass is crushed for fuel, the expressed 

 water containing about fivegrms. sugar per 100 c.c., which would of course be 

 the loss per 100 cane if the discharged megass weighed the same as the cane. 

 In Figs. 139 and 1/^0 are given diagrammatic views of the installation. 



The Naildet Process. In the ordinary process of diffusion, that 

 cell last filled with sliced cane is subjected to the operation known as ' meichage' 

 i.e., the cell is filled from the bottom upwards with juice from the preceding 

 cell, and on drawing off the direction of flow is reversed ; in this process the 

 juice at the bottom is more dilute and is actually the portion that is first drawn 

 off; in addition, the upper layers of juice having passed over the slices of cane 

 are colder than the lower layers. The Naudet patents refer to a system of 

 forced circulation and re-heating, whereby the objections inherent to the usual 

 process of ' meichage* are overcome, and are expressed in the following words 

 in the English patents. 



11 The application of forced circulation to every succeeding cell of a series 

 of cells of a diffusion or macerating battery is accomplished by the use of a 

 pump, the suction side of which communicates with the bottom of the cell 

 having straining boxes intervening to collect small particles of cush-cush or 

 megass, that may be retained in the juice, the delivery side of the pump con- 

 nected to the top of the diffusion vessel having heaters intervening between the 

 pump and the diffusion vessel to bring the juice to the required temperature." 



As applied to the cane sugar industry the process, while including the 

 system of forced circulation, has come to imply a combination of milling and 

 diffusion, with simultaneous liming, clarification and filtration. 



In the process as erected in quite a number of factories the canes are dry 

 crushed in a six-roller mill, an extraction of about 70 per cent, of weight of 

 juice on canes carrying 12 per cent, of fibre being obtained. A cell of the 

 diffusion battery being filled with the megass resulting from the dry crushing 

 of the canes, a quantity of juice corresponding to the megass in the cell is 

 allowed to enter. The cell is then filled with more dilute juice obtained from 

 the diffusion of a previous lot of megass ; from this cell is taken the charge of 

 diluted juice that passes on to the boiling house, the circulation of the juice 



238 



