Improvements in the Manufacture of Sugar.
Year: 1890

page_text: Date of Application, 5th Apr., 1890
Complete Specification Left, 3rd Jan., 1891-Accepted, 14th Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Sugar.
1, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., the
General Patent Office, No. 4, South Street, Finsbury, in the County of Middlesex,
Patent Agents, do hereby declare the nature of this invention (a communication
from abroad by Moriz Weinrich, of St. Louis, Missouri, United States of America,
Gentleman) to be as follows:
My invention relates to the filtering and purification of saccharine solutions or
other solutions in order to separate in a quick and easy way all matters held
in suspension, and in some cases to improve also the colour and purity of the
treated liquids or to dissolve and extract simultaneously the soluble matter contained
in the filtering material.
In order to attain these objects I treat the sugar solutions with any one of the
following materials or with mixtures of them :-
(1) With bagasse (pressed sugar-cane, or exhausted cane-chip comminuted to a
meal or flour.)
(2) With the crude cobs of the Indian corn (maize) comminuted to a meal or
flour.
(3) With the charred cobs of the Indian corn comminuted into small pieces like
bone charcoal or ground to a meal or flour.
(4) With ground oak-bark or any other bark containing tannin
ground cork.
or with
(5) With sugar-cane, sorghum-cane, or sugar-beets comminuted to slices or chips
and then dried.
In treating sugar solutions with meal or flour of bagasse, corn cobs (crude or
charred), bark containing tannin or cork or mixtures of these materials, I go on
in the following way :-
The solution is heated up to about 180° Fahrenheit, and then receives,
according to its purity, an addition of from 2 to 6 per cent. (relatively to the
sugar contained in it) of one of the abovenamed materials. The main part
of the filtering material can consist of the same material, which may have already
been cleansed by washing with water, and only a small portion of the fresh
filtering material has to be added.
The liquid with the added material is now carefully stirred and heated up to
boiling point. In most cases, especially if the purity of the liquor is low, I
prefer to add some lime to the solution, and neutralize it by phosphoric acid,
sulphurous acid, or carbonic acid, as the purity will become raised in this way and
the so-formed precipitate can become, by means of the filtering material, easily
separated from the liquor.
In separating the liquor treated in this way, from the added filtering material
and from all the scum and impurities contained in it, I use three different methods,
each and all of which work satisfactorily.
By the first method, the liquor after being kept hot, is pumped, under
continuous stirring, through filter-presses. The liquor runs off clear and bright.
The cakes which will form in the press, consisting of the filtering material,
and all the scum and slime, are lixiviated in the usual way, then taken out, and
all the scum removed from the material by careful washing and are then ready
to be used again.
2nd method. The liquor is treated in a cylindrical tank with a false bottom
consisting of perforated sheet iron covered with a filter-cloth, which is packed
tight against the side of the tank. Beneath this tank stands another tank of

page_text: the same capacity and which is closed air-tight, and is connected with the bottom
of the upper tank by a pipe. In the lower tank, a vacuum is produced by any
ordinary air-pump. As soon as the liquor is treated in the above described way,
the pipe connecting the two tanks is opened and the liquor is sucked through
the cloth and false bottom by means of the vacuum, into the lower tank. At the
same time, all filtering material, scum, and impurities will settle upon the cloth.
When all the liquor has passed into the lower tank, water is put upon the
sediment on the cloth in order to lixiviate it. This done, the filtering material is
taken out, washed and used again. In order to insure an entirely bright and clear
liquor, the latter is allowed to pass, before it goes to the charcoal-filters, through
filter-presses with very little pressure.
3rd method. The treated liquor is run through a centrifugal-machine which
effects the separation of the liquor from the filtering material and the impurities.
To this end the centrifugal requires a special adaptation. The inner drum or
basket of the centrifugal has to be lined (in place of a wire cloth or perforated
sheet) with a double filter-cloth and carefully tightened to it. The circular edge
or brim of the drum projecting towards its centre, which is generally about six
inches wide, has to be removable and is supplied with a number of bolts or screws
in order to fix it again to the drum.
Whenever the centrifugal is to be used, the brim or edge is removed and a
cylinder consisting of a finely perforated sheet or of a wire cloth (stiffened at the
edge and having a diameter of say 1 to 2 inches less than that of the drum,
but of the same height) is set into the drum. The intermediate annular space
of to 1 inch formed in this way between the drum and the cylinder is then filled
with some of the filtering material, the object being to prevent the slime from
clogging the filter cloth.
This done, the brim is fastened again to the drum, the centrifugal is put in
motion and the treated liquor is allowed to run in. All the filtering material
and scum are retained in the machine, and the liquor, pure but cloudy, will pass
through the filter cloth. In order to have the liquor quite bright and clear, it
can be run now through a filter press as through any other filtering apparatus.
As soon as the layer of filtering material and scum, which will deposit by and by
upon the cylinder set into the drum, reaches a thickness of 4 to 5 inches, the influx
of the liquor is stopped. Hot or cold water is now sprinkled on the layer deposited
upon the cylinder in order to lixiviate it. When this is done, the machine is
stopped the brim taken off, and all the filtering material and scum, also that
between the cylinder and drum, are taken out through the bottom of the drun.
The filter cloth is thoroughly cleaned by steam which enters the space between
the inner and outer drum, so that all the scum dissolved and removed by the
action of the steam, runs off through the bottom of the drum.
Before using any fresh crude cobmeal, it has to be boiled in water for about
one hour, in order to remove all colouring and extractive matters.
At such places where bagasse can be obtained at low prices, it is advisable to
use fresh material every time, in order to save the washing expenses for the used
material, and because the sugar contained in it will generally pay well for the
fuel-value of the bagasse and the expenses for drying and grinding. Besides, fresh
material is always more efficacious than used material. On cane-sugar plantations
the bagasse-meal could-be-prepared-in-such a way that it is sifted out of the bagasse
and used in its moist state at once before it is getting sour. In this way the drying
and grinding is saved; but I generally prefer to have the bagasse dried and
ground as fine as possible, as it will be the more efficacious the finer it is
ground up.
Bagasse-meal is used without any further preparation, but fresh crude cobmeal
before it is used has to be boiled in water for about an hour in order to remove all
colouring and extractive matters before it is brought in contact with sugar-solutions.
The charred corn-cobs broken into small pieces offer an enormous filtering surface,
possessing besides a pretty tough and hard structure. They will form therefore a

page_text: cheap and useful substitute for bone charcoal and are used in the same way as the
latter material.
The dried slices or chips of sugar-cane, of sorghum-cane, or of sugar-beets, can
be used with advantage as a filtering material for sugar-solution and their native or
inherent sugar-contents can be extracted simultaneously with such filtering and with
little or no expense.
For this purpose, I put the dried slices or chips, (and which, if convenient or
desired, may be comminuted or reduced to a yet smaller size), into closed filtering
vessels of about the same size and kind as those used for charcoal, and which can
be connected among themselves to a battery.
The hot sugar-solution is now allowed to run over the chips with pressure.
By diffusing itself through the cells of the chips, the liquor deposits all its foreign
matters held in suspension, and becomes entirely bright, dissolving and extracting
at the same time the sugar normally contained in the chips themselves.
The liquor, by taking up the sugar and other soluble matters of the chips,
increases in its density according to the amount of chips over or through which it
is run.
Therefore the density of the original liquor to be purified has to be regulated
in such a way that the liquor drawn off from the filters shall reach the desired
density.
As soon as a sufficient amount of liquor has passed through the chips, the inflow
of the liquor is stopped, and the chips are edulcorated in the same way as is practised
with bone-charcoal.
The exhausted chips can be dried again, and used for some other purpose.
-
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Sugar.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., the
General Patent Office, No. 4, South Street, Finsbury, in the County of Middlesex,
Patent Agents, do hereby declare the nature of this invention (a communication
from abroad by Moriz Weinrich, of St. Louis, Missouri, United States of America,
Sugar Expert,) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:
My invention relates to the filtering and purification of saccharine solutions or
other solutions in order to separate in a quick and easy way all matters held in
suspension, and in some cases to improve also the colour and purity of the treated
liquids, or to dissolve and extract simultaneously the soluble matter contained in the
filtering material.
In order to attain these objects I treat the sugar solutions with any one of the
following materials or with mixtures of them :-
(1) With bagasse (pressed sugar-cane, or exhausted cane-chips) comminuted to
a meal or flour.
(2) With the crude cobs or the crude stalks of the Indian corn (maize)
comminuted to a meal or flour.
(3) With the charred cobs of the Indian corn comminuted into small pieces like
bone charcoal or ground to a meal or flour.
(4) With ground cork.
(5) With sugar cane, sorghum cane, or sugar beets comminuted to slices or chips
of meal, and then dried.
In treating sugar solutions with meal or flour of bagasse, corn cobs (crude
or charred), corn stalks, or cork, or mixtures of these materials, I go on in the
following way :-

page_text: The solution is heated up to about 180° Fahrenheit, and then receives, according
to its purity, an addition of from 2 to 6 per cent. (relatively to the sugar contained
in it) of one of the abovenamed materials. The main part of the filtering material
can consist of the same material, which may have already been used and then
cleansed by washing with water, and only a small portion of the fresh filtering
material has to be added.
The liquid with the added material is now carefully stirred and heated up to
boiling point. In most cases, especially if the purity of the liquor is low, I prefer
to add some lime to the solution, and neutralize it by phosphoric acid, sulphurous
acid, or carbonic acid, as the purity will become raised in this way and the
so-formed precipitate can become, by means of the filtering material, easily separated
from the liquor.
In separating the liquor treated in this way, from the added filtering material and
from all the scum and impurities contained in it,-I use three different methods,
each and all of which work satisfactorily.
By the first method the liquor after being kept hot, is pumped, under continuous
stirring, through filter presses. The liquor runs off clear and bright. The cakes
which will form in the press, consisting of the filtering material, and all the scum
and slime, are lixiviated in the usual way, then taken out and all the scum removed
from the material by careful washing and are then ready to be used again.
2nd method. The liquor is treated in a cylindrical tank with a false bottom
consisting of perforated sheet iron covered with a filter-cloth, which is packed tight
against the side of the tank. Beneath this tank stands another tank of the same
capacity and which is closed air-tight, and is connected with the bottom of the
upper tank by a pipe. In the lower tank, a vacuum is produced by any ordinary
air-pump. As soon as the liquor is treated in the above described way, the pipe
connecting the two tanks is opened and the liquor is sucked through the cloth and
false bottom by means of the vacuum, into the lower tank. At the same time, all
filtering material, scum, and impurities will settle upon the cloth. When all the
liquor has passed into the lower tank, water is put upon the sediment on the cloth
in order to lixiviate it. This done, the filtering material is taken out, washed and
used again.
In order to insure an entirely bright and clear liquor, the latter is
allowed to pass, before it goes to the charcoal-filters, through filter-presses with
very little pressure.
3rd method. The treated liquor is run through a centrifugal machine which
effects the separation of the liquor from the filtering material and the impurities.
To this end the centrifugal requires a special adaptation. The inner drum or
basket of the centrifugal has to be lined (in place of a wire cloth or perforated
sheet) with a double filter-cloth and carefully tightened to it.
The circular edge
or brim of the drum projecting towards its centre, which is generally about six
inches wide, has to be removable and is supplied with a number of bolts or screws
in order to fix it again to the drum.
Whenever the centrifugal is to be used, the brim or edge is removed and a
cylinder consisting of a finely-perforated sheet or of a wire cloth (stiffened at the
edge and having a diameter of say 1 to 2 inches less than that of the drum, but of
the same height) is set into the drum. The intermediate annular space of to
1 inch formed in this way between the drum and the cylinder is then filled with
some of the filtering material, the object being to prevent the slime from clogging
the filter cloth._
This done, the brim is fastened again to the drum, the centrifugal is put in
motion and the treated liquor is allowed to run in. All the filtering material and
scum are retained in the machine, and the liquor, pure but a little cloudy, will pass
through the filter cloth. In order to have the liquor quite bright and clear,
it can be run now through a filter press or through any other filtering
apparatus.
As soon as the layer of filtering material and scum, which will deposit by and by
upon the cylinder set into the drum, reaches a thickness of 4 to 5 inches, the influx

page_text: of the liquor is stopped. Hot or cold water is now sprinked on the layer deposited
upon the cylinder in order to lixiviate it. When this is done the machine is
stopped, the brim taken off, and all the filtering material and scum, also that
between the cylinder and drum, are taken out through the bottom of the drum.
The filter cloth is thoroughly cleansed by steam which enters the space between
the inner and outer drums, so that all the scum dissolved and removed by the action
of the steam, runs off through the bottom of the drum.
Before using any fresh crude cob-meal, it has to be boiled in water for about one
hour, in order to remove all colouring and extractive matters.
At such places where bagasse can be obtained at low prices, it is advisable to
use fresh material every time in order to save the washing expenses for the used
material, and because the sugar contained in it will generally pay well for the fuel-
value of the bagasse and the expenses for drying and grinding. Besides, fresh
material is always more efficacious than used material. On cane-sugar plantations
the bagasse-meal could be prepared in such a way that it is sifted out of the bagasse
and used in its moist state at once before it is getting sour. In this way the drying
and grinding is saved: but I generally prefer to have the bagasse dried and ground
as fine as possible, as it will be the more efficacious the finer it is ground.
Bagasse meal is used without any further preparation, but fresh crude cob-meal
before it is used has to be boiled in water for about an hour in order to remove all
colouring and extractive matters before it is brought in contact with sugar
solutions.
The charred corn cobs broken into small pieces offer an enormous filtering
surface, possessing besides a pretty tough and hard structure. They will form
therefore a cheap and useful substitute for bone charcoal and are used in the same
way as the latter material.
The dried slices or chips of sugar-cane, or sorghum cane, or of sugar-beets can
be used with advantage as a filtering material for sugar solution, and their native
or inherent sugar-contents can be extracted simultaneously with such filtering and
with little or no expense.
For this purpose, I put the dried slices or chips (and which, if convenient or
desired, may be comminuted or reduced to a yet smaller size) into closed filtering
vessels of about the same size and kind as those used for charcoal, and which can
be connected among themselves to a battery.
The hot sugar-solution is now allowed to run over the chips with pressure.
By diffusing itself through the cells of the chips, the liquor deposits all its
foreign matters held in suspension, and becomes entirely bright, dissolving and
extracting at the same time the sugar normally contained in the chips themselves.
The liquor, by taking up the sugar and other soluble matters of the chips,
increases in its density according to the amount of chips over or through which
it is run.
Therefore the density of the original liquor to be purified has to be regulated
in such a way that the liquor drawn off from the filters shall reach the desired
density.
As soon as a sufficient amount of liquor has passed through the chips, the inflow
of the liquor is stopped, and the chips are edulcorated in the same way as is
practised with bone-charcoal.
If the dried and comminuted sugar cane be used in the shape of a meal or flour,
it can become extracted either in the same way as described above, or it may
become mixed thoroughly with the hot sugar solutions in suitable tanks provided
with agitators, and the mixture pumped under continuous stirring into filter-presses
whence the liquor runs off entirely bright and clear.
The cakes which will form in the press are then lixiviated in the usual way and
the exhausted meal then remaining, with all the mechanical impurities, is taken out
of the press.
The acidity of the sugar solution has to be regulated by adding the necessary
amount of lime.

page_text: The exhausted chips or meal can be dried again, and used for some other
purpose.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is :-
1. The described improved method of purifying sugar-solutions or other solutions
or liquids consisting in filtering the same with or through either of the abovenamed
materials, to wit:-
(a) The comminuted cobs and the stalks of the Indian corn, whether crude or
charred;
(b) Ground cork;
(c) Dried and comminuted bagasse ; '
(d) Mixtures of these materials;
(e) Sugar-cane, sorghum-cane, or sugar-beets comminuted to slices or chips, or
a meal and then dried.
2. Centrifugal machines, adapted in the way described above, for the filtration of
sugar-solutions, or other solutions.
3. Sugar-cane, sorghum-cane, or sugar-beets comminuted to slices or chips and
then dried, as a material for the filtration and purification of sugar-solutions,
extracting simultaneously the soluble matters contained in the chips.
Dated the 3rd day of January 1891.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.