THE DIFFUSION PROCESS 



255 



intended to travel in a direction opposite to a current of water. The Perichon 

 system of bagasse extraction, U.K. patent 7337 of 1896, was operated in 

 Egj'-pt^. It included the sj'stematic lixiviation of the bagasse in trucks 

 with perforated bottoms, combined \\-ith the subsequent milling of the 

 exhausted bagasse. That truck immediately before the final re-crushing 

 mill received water which, after passing through the material, was pumped 

 to the next truck in series. 



The Naudet sj^stem is a combination of milling and diffusion, and is 

 covered by the patents of Naudet and Manoury, 25695 of igoi ; Naudet 

 and Hinton, 27666 of 1903 ; and Naudet, 2928 of 1904. The patents deal 

 with two entirely different features : (i) the combination of milling and 

 diffusion ; (2) the method of diffusion. As regards the first, cane is crushed 

 in a mill and the bagasse conveyed to a diffusion cell, whither also goes, 

 after separate heating and hming, the expressed juice which is circulated 

 over its own bagasse. In this cell, dilution with juice which comes from the 

 rext ceU in series takes place. The 

 addition of water takes place in the last 

 cell in the series, after which the bagasse 

 is milled. In the patent of 1901 it is 

 stated that the dilute juice expressed 

 from the last mill is returned to the 

 battery ; and in the patent of 1903 it 

 is implied that this dilute juice is 

 wasted, the extraction being completed 

 in the battery. The raw juice being 

 limed, heated, and filtered over its ba- 

 gasse, affords a juice which passes direct 

 to the evaporator and ehminates de- 

 fecators and filter-presses. 



The diffusion process refers to the 

 scheme of circulating the juice through 

 a diffuser and heating it externally to 



the battery. A second part of the process claims raising the density of the 

 dra\vn-off juice to the original density of the normal juice even by the 

 addition of molasses, but does not claim the suppression of molasses. The 

 Naudet process has not come into general use, though it remains in success- 

 ful operation in Madeira. 



Geerligs-Hamakers Process. — In 1903, GeerHgs and Hamakers demonstra- 

 ted b\' large-scale experiments in Java that, by diffusing bagasse from a 

 six-roller mill and crusher, an extraction of 98 per cent, was obtainable, 

 with a dilution of 19-6 per cent, on normal juice. This scheme has not been 

 developed. 



Diffusion of Dried Cane. — The resuscitation of an old idea is seen in 

 MacMuUen's proposal, patent 18237 of 1908, to shred and dry the cane, 

 afterwards treating it by diffusion, \vith utiUzation of the fibre in paper- 

 making. It was understood that this partially manufactured material 

 would enter the United States duty free, and it is only under such advantages 

 that the process could hope to be successful. This scheme is not new ; it is 

 included in Crossley's patent 7469 of 1837, and in that taken out by Newton 

 for a foreigner 12033 of 1848. Such a process was operated b}^ Datibree in 



Fig. 153 



