IMPROVEMENTS IN THE MANUFACTURE OF SUGAR
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by James Wilson at the Office of
the Commissioners of Patents, with his Petition, on the 16th May
1871. A communication from abroad by Joseph Alfred Ferdinand
Lair and Charles Raphael Bilange, of Rue du Faubourg Mont-
martre, Paris, in the Empire of France.
I, JAMES WILSON, of Nantes, in the Empire of France, at present
residing at the Cannon Street Hotel, in the City of London, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF SUGAR," to be as follows:--
This Invention has for its object improvements in the manufacture
of sugar.
According to this Invention, in order to obtain crystallizable sugar.
from molasses or low class sugars they are mixed with a milk or paste
of lime to form a saccharate of lime, which on crystallizing or solidifying.
has mixed up with it the salts and organic matters. The saccharate of
lime is afterwards cut up into slices or otherwise reduced to expose it to
the action of water by which the salts and organic matters which are.

page_text: readily soluble are dissolved out from it, whilst the saccharate of lime
being but slightly soluble is little affected. A pure saccharate of lime
is thus obtained, which by subsequent carbonisation yields a pure
sugar which can readily be crystallized in the ordinary ways.
In carrying out this process it is preferred to proceed as follows:-
A milk or paste of lime containing, say, about 25 or 30 per cent. of dry
material is prepared and carefully strained, so that it shall not contain
any trace of gritty material. This paste is mixed with molasses in the
proportion of about 35 parts of pure lime for every 100 parts of sugar
contained in the molasses. The mixture becomes somewhat heated
and is agitated continuously until cool; it is then brought to a density
of about 38 to 40° Beaume, and is placed into a crystallizer, and is kept
cool and allowed to remain at rest for a night to solidify or crystallize.
The next day the mass will be found to have hardened, and will be
perfectly homogeneous if the previous operations have been properly
conducted. The mass is then cut into slices about ½, rd. or 1, an inch
thick. The slices are placed upon wickerwork, or coarse wire cloth,
or other open work gratings within a vessel, where they are to be
washed. The washing vessels are, by preference, arranged in sets of
three, so that the water passing from one may run on to a second, and
from the second to the third; the water run on to the first vessel is
previously saturated with lime to avoid the action of carbonic acid.
From the bottom of the vessel the water is led off by a pipe to the
second vessel, and similarly from the second to the third, and passes off
from the bottom of this third vessel into a receiver. In this way each
vessel is filled from the top and empties itself from the bottom, so that
the denser liquid is always running off. When the water running off
from the first vessel is no longer discolored and its specific gravity has
not been increased, which will be in about 72 hours, the water in the
vessel is slowly run off through a plug at the bottom, and after the
material in the vessel has been allowed to drain, it is removed. The
vessel is then recharged, and becomes the last vessel of the series in
place of the first, and so the washing process is carried on continuously.
The waters thus passed over the saccharate of lime three times as
described should be of a density of from 12 to 16 Beaumé, and carbonic
acid gas is passed through them in a vessel fitted for this purpose, until
they are as neutral as practicable. They are then filtered and evapo-
rated to 40 Beaumé to re-form molasses, and the better the preceding

page_text: process has been carried out the poorer will be the molasses thus pro-
duced. The purified saccharate of lime removed from the washing
vessels is, after being carefully drained, subjected to the action of
carbonic acid gas until it is rendered perfectly neutral; the precipitate
is then filtered, and the clear syrup is treated in the ordinary ways.
The carbonisation of saccharate of lime should take place at a tempe-
rature above 70° and below 80° centigrade, otherwise a magma might
be formed, which would impede the operation and necessitate it being
subjected to a greater heat to dissolve it.
The purity of the saccharate of lime obtained in the manner herein-
before described renders it very suitable for use in the processes of
tempering and clarifying. By thus making use of it in the manu-
facture and refining of sugar it entirely prevents the formation of
glucose.
From the above description it will be seen that an important feature
of this Invention consists in the purification of the saccharate of lime
by taking advantage of the difference of solubility of saccharate of
lime and the salts and other substances mixed with it, as herein
described, and this process is applicable to all saccharates of lime,
whether made according to the mode described as preferable or other-
wise. Other modes than that already described of applying water to
dissolve the salts and other substances contained in the saccharate of
lime may also be adopted, as for example, it may be applied by a centri-
fugal machine or otherwise, so as to perfectly wash the salts and the
other substances from the saccharate of lime.