Improvements in and connected with the Production of Pure Saccharates.
Year: 1895

page_text: Date of Application, 26th Aug., 1895-Accepted, 16th Nov., 1895
COMPLETE SPECIFICATION.
Improvements in and connected with the Production of Pure
Saccharates.
1, PER BENGTSSON HÄRJE, of Lilla Harrie, Örtofta, in the Kingdom of
Sweden, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This invention relates to improvements in the production of pure saccharates in
the manufacture of molasses sugar.
The usual method of washing saccharate of lime is to place it in ordinary filter
presses and then to pass water, or preferably water with a little lime, through the
filter presses so that the liquid percolates through the saccharate cakes and carries
away the salts and other impurities in the same. The saccharate is considered
pure when the liquid issuing from the press is of a light colour.
The water employed in carrying out this process must be as cold as possible and
at a low pressure. In spite of all precaution however a very impure saccharate is
obtained. The juices of such saccharates have a brown colour and are bitter to
the taste in consequence whereof they cannot even be used as inferior syrup.
Experiment has shewn that the water not only washes but also dissolves the
saccharate forming channels in the latter through which it can then flow without
producing any effect, or, especially if inferior molasses is used for the production of
the sugar, it converts the saccharate into a nearly liquid or gelatinous mass thereby
impeding the action of the press and clogging the filter cloths.
It has been ascertained that if the saccharate be washed for a long time it
becomes less purė because of the presence of certain impurities which are more
difficult to dissolve than the saccharate itself.
Furthermore the use of waste lye as a diluent for the molasses (in order to
obtain a concentrated waste lye and to avoid great loss of sugar in the same) is
impracticable as the saccharate is not sufficiently purified by this means.
It will be seen from the above that the cause of the poor results obtained by this
process is that the saccharates are easily dissolved in the washing liquids hitherto
used. If a cheap washing liquid could be produced that practically does not
dissolve the saccharate, then by washing with such a liquid a practically purc
saccharate could be obtained.
According to my invention I employ a solution of a saccharate of the same
composition as the ordinary wash yes, which does not dissolve the saccharate at
all. The washing with such a liquid can be continued for any length of time
without forming channels in the saccharate cakes or converting the latter to a
gelatinous mass. By this means the washing can be done more quickly and at a
bigher temperature, the press worked more easily, the filtering cloths kept
continually soft thereby avoiding constant change, and the greater part of the
raffinose and of the organic calcium salts are removed.
When this process is employed inferior molasses as well as refined syrups rich
in inverted sugar can be used for the production of saccharates.
When a saccharate washed in this manner is saturated and filtered a juice of a
light yellow color is obtained, which has a pleasant sweet taste and is easy to
crystallize.

page_text: lime (CaO) and its property of not dissolving saccharate of lime depends to a
mposed generany or '1-1% of sugar and 0.3-1% of
certain extent on the temperature.
Such a solution is produced:
1. By adding hydrate of lime or powdered lime in excess to a diluted solution of
sugar or saccharate and removing the excess of lime by filtering.
2. By dissolving saccharate of lime in water or water containing lime and
removing the excess of lime by filtering.
3. By causing water or water containing lime to pass through a filtering press or
the like filled with saccharate.
The washing liquid is introduced in any known mauner and in order to economize
the same I employ a solution containing ingredients somewhat purer than those
of the waste lye and afterwards solutions still more pure and finally pure washing
liquid or several filtering apparatus one after another are employed in such a
manner that the washing liquid passes through pipes from one apparatus to
the next.
In the baryta and strontia methods it is usual to employ for the washing
3 to per cent. of a solution of barium hydrate for barium saccharate and
10 per cent. of a solution of strontium hydrate for strontium saccharate.
filtering presses in these cases are dispensed with as a complete washing cannot
The
be effected in the same on account of the great solubility of the saccharates in the
washing liquid.
By adding barium hydrate or oxide in excess to a diluted solution of sugar or
saccharate, so that a saccharate solution of about 0·2-1% of sugar and
3-8% of barium hydrate is formed, a suitable liquid for washing barium saccharate
is obtained.
In the same manner, by adding strontium hydrate or oxide in excess to a dilutel
solution of sugar or saccharate, so that a saccharate solution of about 0·2-2% of
sugar and 6-14% of stroutium hydrate is formed, a suitable liquid for washing
strontium saccharate is obtained.
By using these liquids the saccharates may also be washed in presses.
The production of these washing liquids is effected in a manner similar to that
for the production of saccharate of lime solutions with the difference that
3 to 8 per cent. of a solution of barium hydrate or 6 to 14 per cent. of a solution of
strontium hydrate is used instead of water.
same manner as that herein before described.
The washing itself is done in the
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is —
1. The method of producing pure saccharates by the washing process in the
manufacture of molasses-sugar by passing a washing liquid consisting of a saccharate
solution of 0.1-1 per cent. of sugar and 0.3 to per cent. of lime (CaO) through
the saccharate as described.
2. The manufacture of the washing liquid described in the first claim,
(a) By adding hydrate of lime or powdered lime in excess to a diluted
solution of sugar or saccharate and removing the excess
filtering, or
of lime by
(b) By dissolving saccharate of lime in water or water containing lime and
removing the excess of lime.
(c) By causing water or water containing lime to pass through a filter press
or the like filled with saccharate.
3. A modification of the method specified in the first claim consisting in using a
saccharate solution of 0.2-1 per cent. of sugar and 3 to 8 per cent. of barium
bydrate or 0.2-2 per cent. of sugar and 6 to 14 per cent. of strontium hydrate
which solutions are produced by the method specified in Claim 2.
5

page_text: 4. In order to economize the washing liquids used in the methods described in
the first and third claims,
(a) First washing with a solution of a somewhat higher purity than that of the
waste lye and afterwards with solutions of increasing purity and finally
with pure washing liquid, or,
(b) Causing water as described in (c) Claim 2 to pass through a series of filter
presses or the like one after the other, substantially as described.
Dated the 26th day of August 1895.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.