Processes for Separating Impure Sugar at one Operation into Crystallised Sugar and Molasses.
Year: 1897

page_text: Date of Application, 26th Mar., 1897
Complete Specification Left, 24th Dec., 1897-Accepted, 5th Feb., 1898
PROVISIONAL SPECIFICATION.
Processes for Separating Impure Sugar at one Operation into
Crystallised Sugar and Molasses.
I, MARCUS SACHS, of 4, Ekatherinenstrasse, Kiew, Russia, Manufacturer, do
bereby declare the nature of this invention to be as follows:---
In the existing methods of working the discharge liquors of sugar factories it
was only possible to boil down the liquor to string, and then to obtain by means of
several crystallisation processes occupying considerable time, on the one hand the
yield of sugar and on the other hand molasses. From the filling mass boiled to
string according to the above method there is obtained after completion of crys-
tallisation more or less sugar, and a discharge liquor rich in sugar (third product)
which after being again converted into filling mass by boiling to string, is sub-
jected to a further crystallisation and to centrifugal action, whereby a discharge
liquor (molasses) is obtained which is no longer available for crystallisation.
In some, and even in comparatively many factories the twofold boiling to string
and the twofold crystallisation do not yet produce a final discharge liquor
(molasses) poor in sugar, and in consequence hereof a third boiling to string is
resorted to, and the filling mass is a third time subjected to crystallisation.
The discharge liquors obtained from the first product in sugar factories, require
a period of crystallisation of from eight to twenty days; the farther discharges,
which still have to be boiled and crystallised, require, in consequence of the diffi-
culty with which their sugar crystallises, from 2 to 4 months time to crystallise,
in order to obtain by this means all the available sugar and a single molasses in
the manufacture.
This method of operating had the result that the working up of the several
after products was not completed at the end of beet-working season, the last pro-
ducts being only capable of being worked for sugar some three or four months
after the end of the season. This required a large number of vessels and a cor-
respondingly considerable space for the same.
My present invention has for its object to obviate the necessity of having
more than one single after product for boiling and crystallising, and to effect,
in refineries, molasses desaccharising works, and sorghum sugar works, a saving
of at least one boiling and, one crystallisation of the after products resulting
therein.
By the hereinafter described processes which form the subject of my present
invention the following results may be obtained in sugar factories:-
-
1. By means of a single boiling and a single cooling (crystallisation) there is
obtained from the boiled discharge liquor of the first product at one stroke, sugar
on the one hand and proper molasses on the other hand, without by-products, so
that in sugar factories the technical effect is attained, of obtaining the full yield
of sugar from the beet with only two products (first and second product).
2. The time required for obtaining the total yield of sugar from the discharge

page_text: liquor referred to under (1) is considerably shortened, so that in place of the above
mentioned duration of several months only from 2 to 9 days are required, accord-
ing to the nature of the crystallising vessels employed.
3. The product houses that were heretofore necessary are done away with as the
crystallisation according to my process proceeds very rapidly, and I do not obtain
with the same any subsidiary discharges that could yield sugar by the ordinary
processes, and consequently I do not require the space for the above described
crystallisation of months duration.".
4. My new process enables a continuous working to be instituted, owing to the
fact that at the close of the beet working season there remain no after products
for crystallisation.
5. By my process the total yield of sugar is increased, as I obtain a molasses
poor in sugar.
.
The method of working in a sugar factory operating according to my new pro-
cess would be as follows.
After the beets have been worked and the juices therefrom boiled in the usual
manner and with the ordinary apparatus, the filling mass of the first product; is
obtained which is also crystallised out in the usual manner.
After separating this filling mass into sugar and discharge liquor, this discharge
liquor (second product) is subjected to the treatment according to my invention."
This crude discharge liquor is introduced unpurified into a collecting vessel
before the vacuum apparatus in which the afterproducts of the factory are usually
boiled.
In the collecting vessel is provided a device (such as a steam worm or the like)
by means of which the liquor can be heated. This heated discharge liquor is
then conveyed into the said vacuum apparatus for boiling.
This boiling has to be effected quite differently from the manner in which such
liquors have hitherto been boiled, namely, after the apparatus has been filled up
to above the worm, or heating tubes and the charge then concentrated, fresh liquor
must not be introduced in large quantities at a time but it must be drawn into the
vacuum pan in successive small quantities often repeated and rapidly effected.
According to my process: (a) a small portion of the discharge liquor from the
filling mass of first crystallisation (second product) is first entered into an ordinary
vacuum apparatus or other apparatus operating with vacuum, and is concen-
trated to string test. After this has been effected the boiling is continued under
frequent additions of the same warmed discharge liquors until a sample taken
on a piece of sheet glass shews a crystallisation of the sugar in the product.
If the mass contains a large quantity of medium sized crystals, it is discharged
either entirely, or down to the level of the worm or steam pipes, into a crystallis-
ing pan. The quantity discharged from the apparatus is again replaced by fre-
quent fresh additions followed by boiling, and so on alternately discharging and
adding.
Or the entire contents of the vacuum apparatus are discharged and the boiling
begun again with a fresh charge.
(b) The boiling with partial emptying and repeated additions of the warmed
discharge liquor can be continued until a second pulverulent crystallisation appears
under the crystals first produced.
When this takes place, the entire contents of the apparatus must be eniptied
either into the mass already contained in a crystallising pan, or into an empty
pan, and the process of boiling a fresh charge of the crude discharge liquor
(second product) is repeated as described under (a).
The obligatory interruption of the boiling on the appearance of the second
crystallisation in pulverulent form is prescribed for the reason that on the sub-
jecting of the crystallised filling mass to centrifugal action, the pulverulent
crystals pass through meshes of the centrifugal apparatus, and enrich the dis-
charge with sugar, so that in this case no such molasses poor in sugar can be
obtained as is intended with my process.

page_text: (c) For the development of the desired crystals in the boiling apparatus, the
discharge liquor that is to be supplied to the latter must be previously heated in
the collecting vessel.
The finished boiled filling mass let down from the boiling apparatus into crys-
tallising vessels of any suitable construction is there subjected to a cooling at the
temperature of the factory without warming or further cooling and without addi-
tion of sugar crystals.
In cooling in ordinary mash tuns the mass contained therein can be brought
in from 2 to 4 days to the centrifugal machines by which it is separated into crys-
tallised sugar and molasses.
When cooling the boiled filling mass in small vessels, the above mentioned
result namely the separation by the centrifugal apparatus into sugar and molasses,
is obtained already in from one to two days; in larger vessels however only after
from 6 to 9 days.
By obtaining according to my process the whole of the sugar from the beet
juices in a short time, and without after products, such as result with the ordinary
crystallisation process lasting several months, I am enabled to obtain the advan-
tage of a continuous working, in which only sugar and molasses are obtained.
For the boiled discharge liquors (syrups) treated according to this process, mash
tuns are used with particular advantage for shortening the time of the cooling
(crystallisation) as also for obtaining the greatest possible yield of sugar.
The peculiarity resulting from my process of enabling the syrups (discharge
liquors) to crystallise out completely in the shortest possible time at the ordinary
factory temperature, without the addition of sugar crystals or crystallised filling
mass, so that the impure saccharine mass is separated at one stroke into sugar and
molasses renders it possible to use for the crystallising process a mashing vessel
with single walls and without arrangement for cooling or for heating with steam,
water, air, &c. Of course such simple mashing vessel can be of any construction
either horizontal, vertical, cylindrical, semi-cylindrical, closed, open, &c.
The above mentioned kind of mashing vessels could heretofore only be used for
the first product, while for the crystallization of the after products of sugar fac-
tories their use was excluded.
For the discharge liquors (syrups) boiled to crystallisation according to processes
heretofore employed only mashing vessels with double walls could be used, or
those which were otherwise provided with means whereby the syrups contained
therein, together with the added crystals and crystallised filling mass could be
heated or cooled.
The simple description of mashing vessels, the application of which for the crys-
tallisation of after products is new, possess, in comparison with the mashing
vessels heretofore employed for that purpose, the advantage of cheapness of con-
struction and of cheaper working, in consequence of the saving in steam.
The described process is also applicable to the affination discharges and syrups,
although these are essentially different from the above mentioned discharges as
regards both purity and composition. Also with the affination discharges and
syrups it is possible, with the described means, to effect a boiling to grain and a
separation at one stroke into crystallised sugar and molasses.
The separation of the impure sugar solution into crystallised sugar and molasses
can also be effected by a modification of the above described process. While,
namely, according to the above described process the farther boiling down of the
discharge liquor concentrated to the string test was effected under repeated addi-
tions of the heated discharge liquor until a large portion of the crystallisable sugar
separated, it has been found that the continued boiling down of the discharge
liquor thickened to weak string test until the emptying of the charge can be car-
ried farther, that is, to the same extent as is necessary with the usual boiling down
to string, without waiting for the separation of crystals visible to the naked eye.
The separation of the crystals then takes place in the crystallising pans, the separa-
tion of the sugar being also in this case so complete that the liquor separated from

page_text: the crystals can be considered as molasses in respect of its small percentage of
sugar and high percentage of non-saccharine matter.
The process is characterised by the addition of warmed discharge liquors to the
discharge liquors of the first product concentrated to weak string test, but it differs
from the first described process in that the additions are effected in the manner
usual with ordinary boiling down to string, that is to say, the additions are not
made in small quantities but in large ones. Although the separation of the sugar
crystals does not take place in the vacuum, but only in the crystallising pans, the
separation of the sugar is completely effected so that the liquor separated from the
crystals is molasses. After completion of the crystallising out of the sugar,
the mass is subjected to centrifugal action, whereby the separation into sugar and
molasses is completed. Heretofore, the after product houses, where the crystallis-
ing vessels stood, or the crystallising vessels themselves, were heated. With the
above described process it has been proved advantageous, for facilitating the crys-
tallising of the sugar out of the boiled filling mass, to reduce the temperature of
the latter more rapidly than was heretofore done. This cooling can be effected by
keeping the houses or the vessels in which the crystallisation is effected, cool.
This cooling is partially effected in advance by reducing the temperature of the
filling mass in the vacuum apparatus after it has been completely boiled in the
above described manner, by shutting off the supply of heating fluid to the heating
worms, etc., of the vacuum apparatus while the air pumps are still maintained in
action. When the temperature has been lowered in the boiling apparatus by this
means, the filling mass is discharged into the crystallising vessels.
The crystallisation of the sugar can also terminate at the temperature of the
factory. It is convenient to effect the said cooling of the crystallising room by
means of draught flues or by fans, which draw off the air warmed by the cooling
of the filling mass, such air being conveniently discharged below the furnace
grates of the steam boilers. Another means for reducing the temperature of the
filling mass which is to be subject to crystallisation, consists in effecting the latter
under partial vacuum, instead of under atmospheric pressure. The method can
only be practically employed when the crystallisation is effected in vessels with
stirring apparatus that enable the mass to be loosened, as otherwise the mass
becomes too solid. The crystallisation vessels are for this purpose hermetically
closed and connected to air pumps for producing an exhaust. When the tempera-
ture of the mass has sunk to 30° C., the treatment in the centrifugal machine
can begin.
In the boiling of the discharge liquors according to those above described
methods, in which a boiling to grains (separation of crystals in the vacuum appara-
tus), and not boiling to string is effected, it has proved of advantage, not to boil
the discharge liquor exclusively but to mix molasses therewith.
The process is then carried out as follows:-At the commencement of the boil-
ing of the first quantity of discharge liquors and syrups to be concentrated, as
little as possible of such discharge liquors are entered and are concentrated. The
boiling to grain according to my process is then commenced and is continued
until about 80 p. c. of the space in the vacuum pan which can be used for boiling,
is filled. In place of the discharge liquor and syrup there is then drawn in the
corresponding quantity (about 20 p. c.) of warmed molasses, which is preferably
effected slowly and in successive quantities.
The thickening is then advantageously carried on as far as is possible for
enabling the mass to be discharged from the vacuum pan. When this has been
done, the entire charge is let off into the crystallising vessels, and is mixed with
from 10 to 20 p. c. of molasses preferably heated to the temperature of the filling
inass.
Instead of mixing the filling mass boiled as above described with molasses out-
side the vacuum apparatus, the second addition of molasses can be added to the
finished boiled filling mass while still in the vacuum apparatus, the heating appli-
ances being put out of action. The mixture is facilitated by the provision of a

page_text: stirring device in the apparatus, such stirring device being however only put in
action after the heating devices have been put out of action.
The above described processes can also be employed for the production of
sorghum sugar.
It has also been found that the said processes are not only suited for the working
of discharge liquors of sorghum sugar materials, but also for working sorghum
saccharine juices generally. These juices are, for obtaining the first product,
according to my invention, also added in a warmed condition to the mass after
thickening to string test, whereupon it is boiled to grain or to crystals in the
above described manner. The farther treatment of the filling mass thus obtained
is effected in the known manner.
As the sorghum juices are frequently very impure, it is advisable to improve
them before boiling down, which is effected by the addition of sugar, purer
saccharine juices, or filling mass. The additions must be to such an extent that a
purity of at least 72 is obtained.
These juices can then be boiled according to my process either to grain or to
crystals.
It has furthermore been found that for carrying out the process of converting
discharge liquors of sugar factories and refineries by means of a single boiling
and a single crystallisation at one stroke into sugar and molasses, another improve-
ment can be employed with advantage, whereby I am enabled to attain the
maximum of yield of sugar, and to determine with precision when real molasses
have been obtained.
Real molasses consist of a mother lye which during the crystallising of the
sugar out of an after product filling mass from which is to be separated the sugar
and molasses, has attained that condition in which it can only crystallise molasses
sugar which in the composition of its percentage of sugar and non-saccharine
matter represents the composition of the mother lye itself.
This condition occurs when, after strong concentration of the filling mass from
which the sugar and molasses are to be obtained, the mother lye thereof during
the cooling (crystallising) reaches a percentage of sugar of from 50 to 49 p. c.,
of course, while the crystallised sugar is still contained therein.
Therefore about 50 p. c. in the mother-lye of a filling mass which has reached
the above mentioned necessary concentration in the boiling process, is the boun-
dary where the mother-lye cannot yield by crystallisation any more sugar (after
products sugar) but only the above described molasses sugar.
The more concentrated the filling mass is from which the total attainable sugai
is to be separated, the smaller is the quantity of the mother lye (molasses) and the
lower is its purity, and the greater is the yield in sugar of the filling mass, or dis-
charge liquor.
At the moment when the mother lye sinks to about 50 p. c. of sugar, the pro-
portion of the non-sugar constituents to the sugar becomes more favorable; there
remains therefore less sugar as loss of yield in the residue of the molasses than
if the contrary were the case. When the described condition has been attained
in the mother lye, the crystallisation is interrupted, in order to prevent a crys-
tallised sugar (molasses sugar) which represents in its composition of sugar and
non-sugar only a dry molasses, from passing into the sugar (after products sugar)
and thereby causing subsequently losses in the sugar yield in the following recrys-
tallisation of the after product sugar for producing pure sugar, as for the separa-
tion of the dry molasses, a quantity of water is necessary which in such cases
represents an unnecessary molasses producer.
By the above described method of determining when a true molasses is obtained
and by the distinguishing characteristics of its proper composition, it is also
possible to correctly calculate the yield of impure sugar material relatively to the
percentage of non-sugar with due allowance for the necessary minimum quantity
of water for its separation, remaining in the filling mass, by which quantity of

page_text: water the proportion of the non-sugar to the sugar most favourable for the yield
of sugar is regulated in the molasses.
The essential feature of the present invention consists in the perception that the
concentration of the filling mass must be carried to such a degree that a certain
proportion between sugar and non-sugar is maintained, because this same propor-
tion occurs in the molasses and also that as little water as possible may occur in
the, non-sugar that passes into the molasses, for inasmuch as in the mother lye,.
when it represents molasses, the sugar percentage is equal to the non-sugar plus
water, while for obtaining the total yield of sugar, the non-sugar must be removed
from the discharge liquors, it results that for every per. cent. of non-sugar to be
removed, less sugar passes away with the molasses, as a loss, from the factory.
By the maintenance of the said proportion, which of course may vary in each
separate case, the object of the above described processes, namely the obtaining
from the discharge liquors of sugar factories and refineries crystallised sugar and
molasses at one stroke, is essentially assisted and.
1.promoted.
In carrying out the above described processes it has been found that the manner
in which the discharges that are to be boiled to grain are introduced into the
vacuum vessels is of importance.
If the discharges are introduced into the vacuum vessel in the known manner,
namely above the heating coil or heating pipes, so that the discharges enter from
above, the process does not succeed, or not as well as if the warmed discharges
are introduced at the bottom part of the heated evaporating surface, preferably
at the lowest point and in the middle of the bottom. By this means an eddying
motion of the boiled mass is produced which is of great advantage to the boiling
to grain. The present improvements therefore also consist in the introduction of
the warmed discharges to be boiled down at the middle of the bottom of the
vacuum véssel, instead of from above and at the side as heretofore..
Dated this 26th day of March 1897
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Processes for Separating Impure Sugar at one Operation into
Crystallised Sugar and Molasses.
I; MARCUS SACIS, of 4, Ekatherinenstrasse, Kiew, Russia, Manufacturer, 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:
In the existing methods of working the discharge liquors of sugar factories it
was only possible to boil down the liquor to string, and then to obtain by means of
several crystallisation processes occupying considerable time, on the one hand the
yield of sugar and on the other hand molasses. From the filling mass boiled to
string according to the above method there is obtained after completion of crys-
tallisation more or less sugar, and a discharge liquor rich in sugar (third product)
which after being again converted into filling mass by boiling to string, is sub-
jected to a further crystallisation and to centrifugal action, whereby a discharge
liquor (molasses) is obtained which is no longer available for crystallisation.
In some, and even in comparatively many factories the twofold boiling to string
and the twofold crystallisation do not yet produce a final discharge liquor

page_text: (molasses) poor in sugar, and in consequence hereof a third boiling to string is
resorted to, and the filling mass is a third time subjected to crystallisation.
The discharge liquors obtained from the first product in sugar factories, require
a period of crystallisation of from eight to twenty days; the farther discharges,
5 which still have to be boiled and crystallised, require, in consequence of the diffi-
culty with which their sugar crystallises, from 2 to 4 months time to crystallise,
in order to obtain by this means all the available sugar and a single molasses in
the manufacture.
This method of operating had the result that the working up of the several
after products was not completed at the end of beet-working season, the last pro-
ducts being only capable of being worked for sugar some three or four months
after the end of the season. This required a large number of vessels and a cor-
respondingly considerable space for the same.
Y
My present invention has for its object to obviate the necessity of i having
more than one single after product for boiling and crystallising, and to effect,
in refineries, molasses desaccharising works, and sorghum sugar works, a saving
of at least one boiling and one. crystallisation of the after products resulting
therein.
By the hereinafter described processes which form the subject of my present
invention the following results may be obtained in sugar factories:
1. By means of a single boiling and a single cooling (crystallisation): there is
obtained from the boiled discharge liquor of the first product at one stroke, sugar
on the one hand and proper molasses on the other hand, without by-products, so
that in sugar factories the technical effect is attained, of obtaining the full yield
of sugar from the beet with only two products (first and second product).
2. The time required for obtaining the total yield of sugar. from the discharge
liquor referred to under (1) is considerably shortened, so that in place of the above
mentioned duration of several months only from to 9 days. are required, accord-
ing to the nature of the crystallising vessels employed.
3. The product houses that were heretofore necessary are done away with as the
crystallisation according to my process proceeds very rapidly, and I do not obtain
with the same any subsidiary discharges that could yield sugar by. the ordinary
processes, and consequently I do not require the space for the above described
crystallisation of months duration.
} .::**
4. My new process enables a continuous working to be instituted, owing to the
fact that at the close of the beet working season there remain no after products
for crystallisation.
5. By my process the total yield of sugar is increased, as. I obtain a molasses
poor in sugar.
:
The method of working in a sugar factory operating according to, my new.-pro-
cess would be as follows.
After the beets have been worked and the juices therefrom boiled in the- usual
manner and with the ordinary apparatus, the filling mass of the first product is
obtained which is also crystallised out in the usual manner.: p
After separating this filling mass into sugar and discharge liquor; this discharge
liquor (second product) is subjected to the treatment according to my invention...
This crude discharge liquor is introduced unpurified into a collecting vessel
before the vacuum apparatus in which the after products of the factory are usually
boiled.
.
1
In the collecting vessel is provided a device (such as a steam worm or the like)
by means of which the liquor can be heated. This heated discharge liquor is
then conveyed into the said vacuum apparatus for boiling.
This boiling has to be effected quite differently from the manner in which. such
iquors have hitherto been boiled, namely, after-the apparatus has been filled up
o above the worm, or heating tubes and the charge then concentrated, fresh. liquor
uust not be. introduced in large quantities at a time but it must be drawn into the
acuum pan in successive small quantities often repeated and rapidly effected.

page_text: According to my process: (a) a small portion of the discharge liquor from the
filling mass of first crystallisation (second product) is first entered into an ordinary
vacuum apparatus or other apparatus operating with vacuum, and is concen-
trated to string test. After this has been effected the boiling is continued under
frequent additions of the same warmed discharge liquors until a sample taken
on a piece of sheet glass shews a crystallisation of the sugar in the product.
If the mass contains a large quantity of medium sized crystals, it is discharged
either entirely, or down to the level of the worm or steam pipes, into a crystallis-
ing pan. The quantity discharged from the apparatus is again replaced by fre-
quent fresh additions followed by boiling, and so on alternately discharging and
adding.
Or the entire contents of the vacuum apparatus are discharged and the boiling
begun again with a fresh charge.
(b) The boiling with partial emptying and repeated additions of the warmed
discharge liquor can be continued until a second pulverulent crystallisation appears
under the crystals first produced.
When this takes place, the entire contents of the apparatus must be emptied
either into the mass already contained in a crystallising pan, or into an empty
pan, and the process of boiling a fresh charge of the crude discharge liquor
(second product) is repeated as described under (a).
The obligatory interruption of the boiling on the appearance of the second
crystallisation in pulverulent form is prescribed for the reason that on the sub-
jecting of the crystallised filling mass to centrifugal action, the pulverulent
crystals pass through meshes of the centrifugal apparatus, and enrich the dis-
charge with sugar, so that in this case no such molasses poor in sugar can be
obtained as is intended with my process.
(c) For the development of the desired crystals in the boiling apparatus, the
discharge liquor that is to be supplied to the latter must be previously heated in
the collecting vessel.
The finished boiled filling mass let down from the boiling apparatus into crys-
tallising vessels of any suitable construction is there subjected to a cooling at the
temperature of the factory without warming or further cooling and without addi-
tion of sugar crystals.
In cooling in ordinary mash tuns the mass contained therein can be brought
in from 2 to 4 days to the centrifugal machines by which it is separated into crys-
tallised sugar and molasses.
When cooling the boiled filling mass in small vessels, the above mentioned
result namely the separation by the centrifugal apparatus into sugar and molasses,
is obtained already in from one to two days; in larger vessels however only after
from 6 to 9 days.
By obtaining according to my process the whole of the sugar from the beet
juices in a short time, and without after products, such as result with the ordinary
crystallisation process lasting several months, I am enabled to obtain the advan-
tage of a continuous working, in which only sugar and molasses are obtained.
For the boiled discharge liquors (syrups) treated according to this process, mash
tuns are used with particular advantage for shortening the time of the cooling
(crystallisation) as also for obtaining the greatest possible yield of sugar.
The peculiarity resulting from my process of enabling the syrups (discharge
liquors) to crystallise out completely in the shortest possible time at the ordinary
factory temperature, without the addition of sugar crystals or crystallised filling
mass, so that the impure saccharine mass is separated at one stroke into sugar and
molasses, renders it possible to use for the crystallising process a mashing vessel
with single walls and without arrangement for cooling or for heating with steam,
water, air, &c. Of course such simple mashing vessel can be, of any construction
either horizontal, vertical, cylindrical, semi-cylindrical, closed, open, &c.
The above mentioned kind of mashing vessels could heretofore only be used for

page_text: the first product, while for the crystallisation of the after products of sugar fac-
tories their use was excluded.
For the discharge liquors (syrups) boiled to crystallisation according to processes
heretofore employed only mashing vessels with double walls could be used, or
those which were otherwise provided with means whereby the syrups contained
therein, together with the added crystals and crystallised filling mass could be
heated or cooled.
The simple description of mashing vessels, the application of which for the crys-
tallisation of after products is new, possesses; in comparison with the mashing
vessels heretofore employed for that purpose, the advantage of cheapness of con-
struction and of cheaper working, in consequence of the saving in steam.
The described process is also applicable to the affination discharges and syrups,
although these are essentially different from the above mentioned discharges as
regards both purity and composition. Also with. the affination discharges and
syrups it is possible, with the described means, to effect a boiling to grain and a
separation at one stroke into crystallised sugar and molasses.
The separation of the impure sugar solution into crystallised sugar and molasses
can also be effected by a modification of the above described process. While,
namely, according to the above described process the farther boiling down of the
discharge liquor concentrated to the string test was effected under repeated' addi-
tions of the heated discharge liquor until a large portion of the crystallisable sugar
separated, it has been found that the continued boiling down of the discharge
liquor thickened to weak string test until the emptying of the charge can be car-
ried farther, that is, to the same extent as is necessary with the usual boiling down
to string, without waiting for the separation of crystals visible to the naked eye.
The separation of the crystals then takes place in the crystallising pans, the separa-
tion of the sugar being also in this case so complete that the liquor separated from
the crystals can be considered as molasses in respect of its small percentage of
sugar and high percentage of non-saccharine matter.
The process is characterised by the addition of warmed discharge liquors to the
discharge liquors of the first product concentrated to weak string test, but it differs
from the first described process in that the additions are effected in the manner
usual with ordinary boiling down to string, that is to say, the additions are not
made in small quantities but in large ones. Although the separation of the sugar
crystals does not take place in the vacuum, but only in the crystallising pans; the
separation of the sugar completely effected so that the liquor separated from the
crystals is molasses. After completion of the crystallising out of the sugar
the mass is subjected to centrifugal action, whereby the separation into sugar and
molasses is completed. Heretofore, the after product houses, where the crystallis-
ing vessels stood, or the crystallising vessels themselves, were heated. With the
above described process it has been proved advantageous, for facilitating the crys
tallising of the sugar out of the boiled filling mass, to reduce the temperature of
the latter more rapidly than was heretofore done. This cooling can be effected by
keeping the houses or the vessels in which the crystallisation is effected, cool.
This cooling is partially effected in advance by reducing the temperature of the
filling mass in the vacuum apparatus after it has been completely boiled in the
above described manner, by shutting off the supply of heating fluid to the heating
worms, etc., of the vacuum apparatus while the air pumps are still maintained-in
action. When the temperature has been lowered in the boiling apparatus by this
means, the filling mass is discharged into the crystallising vessels.
The crystallisation of the sugar can also terminate at the temperature of the
factory. It is convenient to effect the said cooling of the crystallising room by
means of draught flues or by fans, which draw off the air warmed by the cooling
of the filling mass, such air being conveniently discharged below the furnace
grates of the steam boilers. Another means for reducing the temperature of the
illing mass which is to be subject to crystallisation, consists in effecting the latter
TI

page_text: under partial vacuum, instead of under atmospheric pressure. The method can
only be practically employed when the crystallisation is effected in vessels with
stirring apparatus that enable the mass to be loosened, as otherwise the mass
becomes too solid. The crystallisation vessels are for this purpose hermetically
closed and connected to air pumps for producing an exhaust. When the tempera-
ture of the mass has sunk to 30° C. the treatment in the centrifugal machine
can begin.
In the boiling of the discharge liquors according to those above described
methods, in which a boiling to grains (separation of crystals in the vacuum appara-
tus), and not boiling to string is effected, it has proved of advantage, not to boil
the discharge liquor exclusively but to mix molasses therewith.
The process is then carried out as follows:-At the commencement of the boil-
ing of the first quantity of discharge liquors and syrups to be concentrated, as
little as possible of such discharge liquors are entered and are concentrated. The
boiling to grain according to my process is then commenced and is continued
until about 80 p. c. of the space in the vacuum pan which can be used for boiling,
is filled. In place of the discharge liquor and syrup there is then drawn in the
corresponding quantity (about 20 p. c.) of warmed molasses, which is preferably
effected slowly and in successive quantities.
The thickening is then advantageously carried on as far as is possible for
enabling the mass to be discharged from the vacuum pan. When this has been
done, the entire charge is let off into the crystallising vessels, and is mixed with
from 10 to 20 p. c. of molasses preferably heated to the temperature of the filling
mass.
Instead of mixing the filling mass boiled as above described with molasses out-
side the vacuum apparatus, the second addition of molasses can be added to the
finished boiled filling mass while still in the vacuum apparatus, the heating appli-
ances being put out of action. The mixture is facilitated by the provision of a
stirring device in the apparatus, such stirring device being however only put in
action after the heating devices have been put out of action.
The above described processes can also be employed for the production of
sorghum sugar.
It has also been found that the said processes are not only suited for the working
of discharge liquors of sorghum sugar materials, but also for working sorghum
saccharine juices generally. These juices are, for obtaining the first product,
according to my invention, also added in a warmed condition to the mass after
thickening to string test, whereupon it is boiled to grain or to crystals in the
above described manner. The farther treatment of the filling mass thus obtained
is effected in the known manner.
As the sorghum juices are frequently very impure, it is advisable to improve
them before boiling down, which is effected by the addition of sugar, purer
saccharine juices, or filling mass.
The additions must be to such an extent that a
purity of at least 72 is obtained.
These juices can then be boiled according to my process either to grain or to
crystals.
It has furthermore been found that for carrying out the process of converting
discharge liquors of sugar factories and refineries by means of a single boiling
and a single crystallisation at one stroke into sugar and molasses, another improve-
ment can be employed with advantage, whereby I am enabled to attain the
maximum of yield of sugar, and to determine with precision when real molasses
have been obtained.
Real molasses consist of a mother lye which during the crystallising of the
sugar out of an after product filling mass from which is to be separated the sugar
and molasses, has attained that condition in which it can only crystallise molasses
sugar which in the composition of its percentage of sugar and non-saccharine
matter represents the composition of the mother lye itself.

page_text: This condition occurs when, after strong concentration of the filling mass from
which the sugar and molasses are to be obtained, the mother lye thereof during
the cooling (crystallising) reaches a percentage of sugar of from 50 to 49 p. c.,
of course, while the crystallised sugar is still contained therein.
Therefore about 50 p. c. in the mother-lye of a filling mass which has reached
the above mentioned necessary concentration in the boiling process, is the boun-
dary where the mother-lye cannot yield by crystallisation any more sugar (after
products sugar) but only the above described molasses sugar.
The more concentrated the filling mass is from which the total attainable sugar
is to be separated, the smaller is the quantity of the mother lye (molasses) and the
lower is its purity, and the greater is the yield in sugar of the filling mass, or dis-
charge liquor.
At the moment when the mother lye sinks to about 50 p. c. of sugar, the pro-
portion of the non-sugar constituents to the sugar becomes more favorable; there
remains therefore less sugar as loss of yield in the residue of the molasses than
if the contrary were the case. When the described condition has been attained
in the mother lye, the crystallisation is interrupted, in order to prevent a crys-
tallised sugar (molasses sugar) which represents in its composition of sugar and
non-sugar only a dry molasses, from passing into the sugar (after products sugar)
and thereby causing subsequently losses in the sugar yield in the following re-crys-
tallisation of the after product sugar for producing pure sugar, as for the separa-
tion of the dry molasses, a quantity of water is necessary which in such cases
represents an unnecessary molasses producer.
By the above described method of determining when a true molasses is obtained
and by the distinguishing characteristics of its proper composition, it is also
possible to correctly calculate the yield of impure sugar material relatively to the
percentage of non-sugar with due allowance for the necessary minimum quantity
of water for its separation, remaining in the filling mass, by which quantity of
water the proportion of the non-sugar to the sugar most favorable for the yield
of sugar is regulated in the molasses.
The essential feature of the present invention consists in the perception that the
concentration of the filling mass must be carried to such a degree that a certain
proportion between sugar and non-sugar is maintained, because this same propor-
tion occurs in the molasses and also that as little water as possible may occur in
the non-sugar that passes into the molasses, for inasmuch as in the mother lye,
when it represents molasses, the sugar percentage is equal to the non-sugar plus
water, while for obtaining the total yield of sugar, the non-sugar must be removed.
from the discharge liquors, it results that for every per cent. of non-sugar to be
removed, less sugar passes away with the molasses, as a loss, from the factory.
By the maintenance of the said proportion, which of course may vary in each
separate case, the object of the above described processes, namely the obtaining
from the discharge liquors of sugar factories and refineries crystallised sugar and
molasses at one stroke, is essentially assisted and promoted.
In carrying out the above described processes it has been found that the manner
in which the discharges that are to be boiled to grain are introduced into the
vacuum vessels is of importance.
If the discharges are introduced into the vacuum vessel in the known manner,
namely above the heating coil or heating pipes, so that the discharges enter from
above, the process does not succeed, or not as well as if the warmed discharges
are introduced at the bottom part of the heated evaporating surface, preferably
at the lowest point and in the middle of the bottom. By this means an eddying
motion of the boiled mass is produced which is of great advantage to the boiling
to grain. The present improvements therefore also consist in the introduction of
the warmed discharges to be boiled down at the middle of the bottom of the vacuum
vessel, instead of from above and at the side as heretofore.

page_text: 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 I
claim is:-
1. A process of boiling to grain or crystals the discharge liquors of the first pro-
duct of sugar refineries, molasses desaccharising works, and affination processes,
and which have hitherto only been boiled down to string, consisting in first boiling
down a certain quantity of the liquor in the vacuum apparatus in the usual
manner, and then adding consecutively thereto farther portions of the liquor
which have been previously heated, substantially as described.
2. The application of the process referred to in the first claim to the separation
of the said discharge liquors, at one stroke, into crystallised sugar and molasses,
without after products, by subjecting the mass after the boiling to a cooling pro-
cess and separation by centrifugal action substantially as described.
3. A process for boiling the discharge liquors referred to in the first claim,
wherein the ordinary process of boiling down to string is applied to the portions of
discharge liquor previously heated as stated in the said claim, in order to effect
by subsequent cooling and subjecting to centrifugal action, a separation at one
stroke into sugar and molasses, substantially as described.
4. In the processes referred to in Claims I to 3, the method of cooling the vessels
in which the crystallisation of the sugar is carried out, or the chambers contain-
ing the same, substantially as described.
5. In the processes referred to in Claims 1 to 4, subjecting the completely boiled
filling mass while still in the vacuum apparatus, before its discharge into the
crystallising vessels, to the action of partial vacuum for accelerating the cooling
of the filling mass substantially as described.
6. In the processes referred to in Claims 1 to 5, effecting the crystallisation of
the sugar under partial vacuum instead of under atmospheric pressure, substan-
tially as described.
a
7. In the processes referred to in Claims 1, 2, 4, 5 and 6, the method of
adding molasses during the boiling of the discharge liquors, and also adding
farther quantity to the completely boiled filling mass, either while, still in
the vacuum apparatus or when in the crystallising vessels, substantially as
described.
8. In the process referred to in the seventh claim, the use of a stirring
device in the boiling apparatus for mixing the added molasses with the completely
boiled filling mass, without farther boiling or heating, substantially as
described.
9. The use for the crystallisation or cooling of the after products in the processes
referred to in Claims 1 to S, of mashing apparatus having single walls and with-
out devices for cooling or heating, substantially as described.
10. Process for working sorghum juices by boiling and cooling for obtain-
ing an increased yield of crystallised sugar, consisting in boiling to grain
or crystals previously warmed juices, the mass being afterwards subjected to
farther crystallisation by cooling in crystallising vessels, substantially as
described.
11. In the application of the processes referred to in Claims 1 to 10 to sorghum
sugar juices having a less purity than 72, the method of adding sugar, purer sugar
juices or filling mass thereto substantially as described.
12. In the process referred to in Claims 1 to 11 the method of carrying the con-
centration of the filling mass so far that there shall exist in the filling mass such
à proportion of water and non-sugar as is necessary in order that the discharge
obtained from the filling mass after cooling and crystallisation shall constitute
real molasses, substantially as described.
13. In the process referred to in Claims 1 to 12 the method of introducing the
warmed discharges into the vacuum pan at the bottom part of the heated

page_text: evaporating surface, preferably at the lowest point and in the middle of the
bottom.
Dated this 94th day of Docomo 1807
ABEL & IMRAY,
Agents for the Applicant.