Vol. V. No. 106. 



THE AGRICULTURAL NEWS. 



14T 



The Naudet Diffusion Process in Trinidad. 



The Harvey Engineering Co., Ltd., has addressed 

 to the Louisiana Planter the following letter, dated 

 March 24, 1906, with reference to the working of the 

 Naudet diffusion process for extracting sugar from 

 the cane : — 



As the makers of the above-named machinery, we think 

 it may interest some of your readers to hear of the progress 

 being made by this new process, which is now at work in the 

 island of Madeira, also in the islands of Trinidad, Porto Rico, 

 and Cuba, in the West Indies. We have just received a few 

 figures regarding the installation we erected last year on 

 Caroni sugar estate, Trinidad, which no doubt will prove 

 interesting to your readers. 



This new process was only started for the first time in 

 Trinidad last crop, and is about four times larger than the 

 plant at Madeira, so that this was the first time the process 

 had been installed on a large scale, grinding about 600 tons 

 of cane per day, and, naturally, being entirely new to the 

 people, there were many difficulties and drawbacks in work- 

 ing the process to be overcome, which was to be expected, 

 considering the great revolution this process accomplishes in 

 the manufacture of cane sugar. Still, last year the entire 

 crop was taken otf by the Naudet process, and gave a much 

 better result than the previous year, which was done by 

 double-crushing mills. This year a number of important 

 improvements have been made, so that the results are even 

 still better. The owner of the estate writes to us as follows : 

 ' The alterations and improvements which you have made on 

 your Naudet machinery for this crop have been most satis- 

 factory and gave no trouble at all — in fact, the whole 

 machinery works like clockwork. The average extraction for 

 two weeks was 95 per cent., and last week for two days the 

 extraction was 97-2 and 97-7 per cent. As to the fuel 

 question, we have six boilers and only burn coal under one 

 of them ; the other five boilers give ample steam and the 

 only fuel used is the exhausted megass from the Naudet 

 battery.' 



Fi'om this it will be seen that this new process extracts 

 at least 97 per cent, of the total sucrose in the cane, .so 

 that only 3 per cent, of the sucrose is lost, which is 

 a much higher extraction than any nine-roller mill has ever 

 yet been able to attain. The juice is also much purer, as 

 the canes have only passed through one crushing. 



As regards the fuel question : we calculate that the coal 

 used under the one boiler will work out at about 1 i to 2 cwt. 

 of coal per ton of sugar made, but this is a small matter when 

 the extra sugar recovered is considered. Also, the manager 

 of Caroni estate informs us that he is in hopes, before the 

 end of the crop, of working the factory without any 

 additional fuel beyond the megass from the Naudet process. 



Owing to the juice being limed, superheated, and thus 

 sterilized, within five or ten minutes after being expressed 

 from the mill, and thereafter enclosed entirely from the 

 atmosphere, there is practically little or no inversion what- 

 soever. The juice is so thoroughly clarified by the circulation 

 through the megass in the Naudet battery, and so freed from 

 all impurities and gummy matters, that, when evaporated, it 

 becomes a syrup which works very freely in the vacuum 

 pans. Therefore, not only is the extraction of the sucrose 

 almost perfect, but the recovery of actual sugar from the 

 juice is also high, so that about 8 tons of cane only are 

 required to make 1 ton of sugar. 



Another point is the simplicity and easily controlled 

 operations of manufacture, as no clarifiers, subsiders, 

 eliminators, or filter presses are used. The juice from the 



first mill is immediately limed and heated, passes through 

 the Naudet macerating battery, and, when dark crystals for 

 refining purposes are required, no sulphur is used, but the 

 juice passes on direct from the Naudet battery into the triple 

 effect, and so to the vacuum pans, crystallizers, and 

 centrifugals, in the usual manner ; when yellow sugar is 

 required, the juice must be sulphured; when white sugar is 

 desired, then additional sulphuring and Philippe or other bag 

 filters must be used. 



These results amply prove that this process is one which 

 will have serious consideration in the future, and place the 

 new process beyong being called experimental, as this estate 

 in Trinidad is now taking off its second crop by the Naudet 

 process in a most satisfactory manner. 



Sugar-cane Experiments in Cuba. 



Previous results of experiments with varieties of 

 sugar-cane at Central Soledad, Cuba, have already been 

 published in the Agricultural Netvs (Vol. II, p. 179, 

 Vol. Ill, p. 179, Vol. IV, p. 146). It is now possible, 

 through the kindness of Mr. E. F. Atkins, to publish 

 some of the results obtained for the last season at the 

 Harvard Experiment Station in Cuba. The following is 

 taken from a letter dated April 17, 1906 : — 



I take pleasure in enclosing our report on cane seedlings 

 which I hope may interest you, also the annual analysis of 

 our foreign canes. The past summer was a very dry one, and 

 our garden suffered in consequence, but all the canes were 

 subject to the same conditions, and their comparisons prove 

 useful. 



I find that very few of the imported varieties of canes 

 are holding up well in the fields after two or three years j 

 they do not seem to have the same vigour as the Cuban 

 canes. On the other hand, some of them are much more 

 prolific in seed than our own varieties, and now that we 

 have succeeded at last in getting some seedlings, I hope some 

 of the crosses may develop into valuable canes. 



The following results were given by the West Indian 

 varieties that had been obtained through the Imperial 

 Department of Agriculture : — 



These varieties compare favourably with others that are 

 under experiment, and it is particularly interesting to note 

 the improvement shown by Caledonian Queen in purity of 

 juice, whereas B. 208 has given slightly poorer results than 

 previously, owing to an exceptionally dry season. 



