Improvements in the Manufacture of Sugar.
Year: 1895

page_text: Improvements in the Manufacture of Sugar.
A communication by HENRI ARMAND JOSEPH MANOURY, of 7 Rue du Helder,
Paris, in the Republic of France, Engineer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E. of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool and 6 Bank Street,
Manchester both in the County of Lancaster, 118 New Street Birmingham in
the County of Warwick and 31 High Holborn in the County of Middlesex,
Civil Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has for its object to effect in a single operation the separation of
the sugar and the molasses contained in the syrups of sugar works and refineries
without making use of special agents or costly apparatus.
It consists on the one hand of a system of rational regulation of the composition
of the masses-cuites in such a way that the mother liquor which surrounds the
crystals consists solely of molasses; and on the other hand in a method of treatment
of these masses-cuites after removal from the boiler with a view of ensuring an
easy separation of the crystals and the molasses. These two phases of the process
will now be successively described.
The principle of the invention consists in always obtaining masses-cuites of the
first cast containing only sugar in crystals and molasses; it may happen however
in consequence of the impurity of the syrups run into the boiler that the mother
liquor surrounding the crystals of the masse-cuite may present precisely the
condition herein before mentioned and be in fact molasses; but it is necessary to
ensure this with precision, and in all cases the operation of centrifugalling must be
conducted in a special manner which will be hereinafter explained in order that
the liquid separated out shall be only molasses. But most commonly the mother
liquor contains syrup capable of crystallizing, and the means employed will now be
explained by which it may consist entirely of molasses.
It may first be just pointed out that what is called the quotient of purity is the
relation between the weight of sugar contained in a liquid and the weight of dry
substances (sugar and impurities) that it contains. For syrups derived from
beetroot when this proportion is equal to or below 0-60 it is admitted that they are
composed solely of molasses, for cane sugar this quotient of purity may descend
to 0.40).
Take for example a masse-cuite derived from beetroot and containing

page_text: which shows that this liquid contains sugar capable of crystallization seeing that
the quotient of purity of the molasses from beetroot may reach 0-60 at most.
In order to reduce this purity without reducing the proportion of 7% of water
necessary for ensuring the fluidity of the masse-cuite, a suitable proportion of
molasses arising from the centrifugalling of the masses previously treated is
introduced into the boiler and the concentration is then effected in such a way as to
evaporate the excess of water contained in these molasses, that is to say, anything
exceeding the 7% which has been admitted to be necessary for the operations of
running or flowing and centrifugalling.
Admitting that the composition of these molasses is as follows :—
assigned of 0.60 which proves that the mother liquor of the masse-cuite is composed
solely of molasses.
It is thus seen that in the example given it is preferable to effect the boiling in the
case of pure beetroot syrup by filling up to about three-fourths of the effective capacity
of the boiler, and to complete the filling up by feeding with molasses derived from
a previous centrifugalling, and placed in a gauged tank with a graduated float so
that only the quantity calculated for reducing the purity of the mother liquor
below 0-60 is introduced. When this has been done, the evaporation is continued
until only the 7% of water necessary for the running and for the easy centri-
fugalling is obtained.
Experience has shown that it would be very difficult to operate the centrifugalling
of the masse-cuite maintaining it exactly at the temperature which it had when
flowing, and this is why it is preferable to operate on the masse suitably cooled.
This cooling of the masse-cuite produces a super-saturation of the mother liquor
which then no longer possesses the same dissolving power and there must be added
thereto the quantity of water necessary for dissolving the sugar and the impurities

page_text: precipitated by the cooling. This addition may be made in the form of pure
water but it is preferable to have it assume the form of diluted molasses.
For this object the masse-cuite is cooled in an agitator provided with a false
bottom in which cold water circulates in such a way as to rapidly bring the
temperature of the centrifugal chamber say to 20° for instance. Then a quantity
of water precisely calculated (say about 3 %) is introduced into the agitator
preferably in the form of diluted molasses in order to dissolve only the sugar and
the molasses precipitated by the cooling of the masse and in this manner the liquor
separated by the centrifugals is certain to be composed solely of molasses.
Dated this 11th day of February 1895.
A communication by HENRI ARMAND JOSEPH MANOURY, of 7 Rue du Helder,
Paris, in the Republic of France, Engineer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S. M.I.M.E. of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street,
Manchester, both in the County of Lancaster, 118 New Street, Birmingham in the
County of Warwick and 31 High Holborn in the County of Middlesex, Civil
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 has for its object to effect in a single operation the separation of
the sugar and the molasses contained in the syrups of sugar works and refineries
without making use of chemical agents or costly apparatus.
It consists on the one hand of a system of rational regulation of the composition
of the masses-cuites in such a way that the mother liquor which surrounds the
crystals consists solely of molasses; and on the other hand in a method of treatment
of these masses-cuites after removal from the boiling pan with a view of ensuring
an easy separation of the crystals and the molasses. These two phases of the
process will now be successively described.
The principle of the invention consists in always obtaining masses-cuites of the
first cast containing only sugar in crystals and molasses;
It may first be just pointed out that what is called the quotient of purity is the
relation between the weight of sugar contained in a liquid and the weight of dry
substances (sugar and impurities) that it contains. For syrups derived from
beetroot when this proportion is equal to or below 0-60 it is admitted that they
are composed solely of molasses, for cane sugar this quotient of purity may
descend to 0.40.
Take for example a masse-cuite derived from beetroot and containing

page_text: which shows that this liquid contains sugar capable of crystallization seeing that
the quotient of purity of the molasses from beetroot may reach 0.60 at most.
In order to reduce this purity without reducing the proportion of 7% of water
necessary for ensuring the fluidity of the masse-cuite, a suitable proportion of
molasses arising from the centrifugalling of the masses previously treated is
introduced into the boiling pan and the concentration is then effected in such a way
as to evaporate the excess of water contained in these molasses, that is to say,
anything exceeding the 7% which has been admitted to be necessary for the
operations of running or flowing and centrifugalling.
Admitting that the composition of these molasses is as follows
21 +140
assigned of 0.60 which proves that the mother liquor of the masse-cuite is composed
solely of molasses.
It is thus seen that in the example given it is preferable to effect the boiling in
the case of pure beetroot syrup by filling up to about three-fourths of the effective
capacity of the boiling pan, and to complete the filling up by feeding with molasses
derived from a previous centrifugalling, and placed in a gauged tank with a
graduated float so that only the quantity calculated for reducing the purity of the
mother liquor below 0-60 is introduced. When this has been done, the evaporation
is continued until only the 7% of water necessary for the running and for the easy
centrifugalling is obtained.
It is therefore evident that whatever may be the composition of the masse-cuite
to be treated, the exact proportion of molasses which must be introduced in order
to attain the desired result, may be calculated in the manner hereinbefore described.
Experience has shown that it would be very difficult to operate the centrifugalling
of the masse-cuite maintaining it exactly at the temperature which it had when
flowing, and this is why it is preferable to operate on the masse suitably cooled.

page_text: This cooling of the masse-cuite produces a super-saturation of the mother liquor,
which then no longer possesses the same dissolving power, and there must be added
thereto the quantity of water necessary for dissolving the sugar and the impurities
precipitated by the cooling. This addition may be made in the form of pure water,
but it is preferable to have it assume the form of diluted molasses.
For this object the masse-cuite is cooled in an agitator provided with a false
bottom in which cold water circulates in such a way as to rapidly bring the
temperature of the centrifugal chamber say to 20° for instance; but at this
temperature, the water does not dissolve more than twice its weight of sugar in
place of three times which it dissolved at the melting temperature, and consequently
for a masse cuite containing 7% of water, 7% of sugar will be precipitated which
will necessitate the introduction into the agitator of 31% of water to exactly
dissolve the precipitated sugar and restore to the mother liquor the necessary
fluidity for the centrifugalling.
It is therefore easy to calculate for each case the quantity of diluted molasses
which must be introduced into the agitator in order to provide the amount of water
necessary for dissolving only the sugar and the impurities precipitated by the
cooling, and in this manner it will be certain that the liquid separated by the
centrifugals will be composed solely of molasses.
It is therefore evident that the use of an exactly determined quantity of molasses
has the effect, in the first phase of the process, of imparting to the impoverished
masse-cuite the necessary fluidity for the formation of the whole of the crystals of
sugar which it can produce, whereas otherwise its pasty condition would prevent
the last crystals from forming, and that in the second phase of the process the use
of a given quantity of diluted molasses has also the effect of increasing the fluidity
of the cooled masse in order to permit of its being centrifugalled under favourable
conditions, whilst allowing only the sugar, and the impurities precipitated by the
cooling, to be dissolved, in order to ensure that the liquid separated by this
centrifugalling will be molasses from which sugar can no longer be crystallized by
concentration.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
:-
1. The method of treating masse-cuite in sugar making and refining, which
consists in introducing into the boiling pans towards the end of the boiling, such a
quantity of molasses that after the water contained in said molasses in excess of
the 7% necessary for melting has been evaporated, the mother liquor containing
the crystals of sugar has a quotient of purity equal or inferior to that of the
molasses, substantially as herein before described.
2. The method of treating masses-cuites in sugar making and refining, consisting
in adding thereto towards the end of the boiling a given quantity of molasses,
and in rapidly cooling the masse run from the boiling pans to the ordinary
temperature of centrifugalling by means of an agitator having a circulation of cold
water and in then adding to the cooled masse a given quantity of diluted molasses
according to the differences in solubility of the sugar in the water at the temperature
of running and at the temperature of the centrifugalling, so that the quantity of
free water contained in said molasses dissolves only the sugar and the impurities
precipitated by the cooling in order to ensure that the liquid separated out by the
centrifugalling shall be molasses substantially as described.
Dated this 23rd day of October 1895.
WM. P. THOMPSON & Co.,
Agents.