IMPROVEMENTS IN TREATING RESIDUAL LIQUIDS OBTAINED IN MANUFACTURING OR REFINING SUGAR, AND IN APPARATUS " THEREFOR
Year: 1876

page_text: LETTERS PATENT to Hugh William Walker, Sugar Refiner, and Thomas Law
Patterson, Analytical Chemist, both of Greenock, in the County of Renfrew,
North Britain, for the Invention of "IMPROVEMENTS IN TREATING RESIDUAL
LIQUIDS OBTAINED IN MANUFACTURING OR REFINING SUGAR, AND IN APPARATUS
"
THEREFOR.”
Sealed the 21st December 1876, and dated the 7th September 1876.
PROVISIONAL SPECIFICATION left by the said Hugh William Walker and
Thomas Law Patterson at the Office of the Commissioners of Patents on the
7th September 1876.
HUGH WILLIAM WALKER, Sugar Refiner, and THOMAS LAW PATTERSON,
Analytical Chemist, both of Greenock, in the County of Renfiew, North Britain.
"IMPROVEMENTS IN TREATING RESIDUAL LIQUIDS OBTAINED IN MANUFACTURING OR
REFINING SUGAR, AND IN APPARATUS THEREFOR."
This Invention relates to the treatment of low syrups, sweet water, charcoal
water, and other residual liquids obtained in the process of sugar refining, and of
molasses and other residual liquids obtained in the manufacture of cane sugar, or
beetroot sugar, or other sugar, and has for its object the production of an improved
golden syrup therefrom.
The liquids referred to often contain a fungus, ferment, or other impurity which is
not removed by filtration or animal charcoal, and which when allowed to remain
causes an objectionable dunness or turbidity in the resulting syrup. It also often
happens that golden syrup or treacle when cooled in the ordinary way after con-
centration, and even in closed vessels deteriorates in color and becomes dim or
turbid.
The Invention consists in preventing or removing the defects first referred to by
adding an alkaline silicate to the syrup or liquid when in a neutral or nearly neutral
state, or a soluble phosphate or a salt of alumina may be used instead of the silicate.
The Invention also consists in preventing the defects secondly referred to by
cooling the concentrated syrup in a rapid and improved manner, and preferably in
apparatus designed for the purpose.
In some cases the preliminary treatment alone, and in others the final rapid

page_text: cooling alone is sufficient for the purpose in view, while some syrups or liquids
require both.
În carrying out the Invention any of the syrups or sweet liquids, or any mixture
thereof is first treated by any known process for rendering the final product
uncrystallisable, and when the liquid is in the blow-up or other suitable vessel at
about the ordinary specific gravity of 1.25, and at a temperature of from 160 to
200 degrees Fahrenheit, but preferably at 180 degrees, it is neutralised by adding
an alkaline carbonate, preferably that of soda; then for every 100 cubic feet of
liquid in the vessel there nie added 10 to 40 pounds of silicate of potash or soda
(preferably that containing most silica), either in the concentrated state or diluted
with 3 or 4 times its voluine of water. The contents of the vessel are thoroughly
mixed by any suitable mechanical stirrer or by injecting open steam, and the
mixture is subsequently filtered. The filtiate which is clear is next rendered
slightly acid with sulphuric, bydrochloric, or other suitable acid, when it will be
ready for filtration through animal charcoal in the usual manner.
It is sometimes preferable to proceed as follows:-When the syrup or liquid is
derived from beetroot, and when it is not wished to increase the soluble salts in the
product, that is to say, to neutralise it by adding lime or its carbonate, and to then
add to it a solution of phosphate of lime (rendered soluble by sulphuric acid) in
quantity equivalent to from 3 to 5 pounds of char dust or mineral phosphate of the
same strength for every 100 cubic feet of liquid of a specific gravity of about 1.25
Or for the phosphate of lime there may be substituted sulphate or other suitable
salt of alumina, or a mixture of these prepared from any mineral or otherwise may
be used The liquid is thoroughly stirred, and a further quantity of line or its
carbonate is added until the liquid is neutral or nearly so, and the liquid is then
filtered and afterwards treated with charcoal.
When color is not an object the liquid may after any modification of the pre-
liminary treatment be at once concentrated without treatment with charcoal.
In carrying out the second part of the Invention the syrup may be rapidly cooled
in any suitable refrigerating apparatus, but the apparatus preferred is similar to a
surface condenser but made with vertical tubes, down through which tubes the
syrup flows under some pressure whilst cold water ascends on the outside. The
cooling surface should contain about 200 square fect for each inch of area of the
discharge cock when the syrup is filled into puncheons from a height of 20 to
25 feet.
The cooling apparatus is by preference situated below a cistern into which the
syrup is transferred from the concentrating pan, and the discharge cock from which
the puncheons are filled is at a still lower level, so that the syrup may flow by
gravitation through the apparatus whenever the discharge cock is opened
Where there is not sufficient height for arranging the apparatus in the manner
described the syrup may be pumped or otherwise forced through the cooling
apparatus at a rate due to a pressure of 15 or 16 pounds per square inch.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Hugh William Walker and Thomas Law Patterson in the Greit.
Seal Patent Office on the 6th March 1877.
HUGH WILLIAM WALKER, Sugar Refiner, and THOMAS LAW PATTERSON, Analytical
Chemist, both of Greenock, in the County of Renfrew, North Britun. "IMPROVE-
MENTS IN TREATING RESIDUAL LIQUIDS OBTAINED IN MANUFACTURING OR REFINING
SUGAR, IN IN APPARATUS THEREFOR."
Our said Invention relates to the treatment of low syrup, sweet water, charcoal
water, and other residual liquids obtained in the process of sugar refining, and of
molasses and other residual liquids obtained in the manufacture of cane sugar, or

page_text: beetroot sugar, or other sugar, and has for its object the production of an improved
golden syrup therefrom.
•
The liquids referred to often contain a fungus, ferment, or other impurity which
is not removed by filtration or animal charcoal, and which when allowed to remain
causes an objectionable dimness or turbidity in the resulting syrup. It also often
happens that golden syrup or treacle when cooled in the ordinary way after con-
centration, and even in closed vessels deteriorates in color and becomes dim or
turbid.
It will thus be obvious that in applying our Invention to any particular residual
liquid or syrup, regard must be had to the kind of dimness or turbidity to which it
is found by trials to be specially liable, and in many cases it will be found that the
treatment must comprise processes. directed towards the prevention of dimness or
turbidity likely to be occasioned in all the ways herein-before indicated.
The dimness or turbidity due. to the action of fungus, or ferment, or other
impurity not separable by filtration is by our Invention prevented by using a
chemical agent of such a nature that it can be thoroughly mixed with the residual
liquid or syrup in a dissolved and clear condition, and afterwards be precipitated in
a state of minute division, and so as in settling from all parts of the liquid to
entangle and carry down with it the fungus, ferment, or other impurity, and
thereby insure its complete separation on subsequent filtration The chemical
agent used must of course be such as not to injure the syrup, and what we employ is
either an alkaline silicate or a soluble phosphate or a salt of alumina, any one of
which may be used indifferently and answers the purpose in view.
"
In carrying out our Invention the sweet liquid or syrup is first treated by any
suitable processes for rendering the final product uncrystallisable, but we do not
claim such processes as they are well known. When the liquid is in the "blow-up
or other suitable vessel at about the ordinary specific gravity of 125, and at a tem-
perature of from 160 to 200 degrees, Fahrenheit, but preferably at 180 degrees, we
make it neutral by adding an alkaline carbonate, preferably that of soda; then for
every 100 cubic feet of liquid 'in the vessel we add from 10 to 40 pounds of silicate
of potash or of soda (preferring that containing most silica) either in the con-
centrated state or diluted with 3 or 4 times its volume of water. The contents of
the vessel are thoroughly mixed by any suitable mechanical stii rer or by injecting
open steam, and the mixture is subsequently filtered. The filtrate which is clear is
next rendered slightly acid with sulphuric, hydrochloric, or other suitable acid, the
silica is thereby precipitated or separated in a state of minute division, and combines
with or adheres to the fungus, ferment, or other impurity so as to remove the same
on the liquid being subsequently filtered. The liquid is treated with animal
charcoal in the usual way to remove color.
When first neutralising the sweet liquid or syrup lime or its carbonate may be
used for that purpose, and then a solution of phosphate of lime (rendered soluble by
sulphuric acid) is added in quantity equivalent to from 3 to 5 pounds of char dust
or mineral phosphate of the same strength for every 100 cubic feet of liquid of ar
specific gravity of about 125. Or for the phosphate of lime there may be sub-
stituted sulphate or other suitable salt of alumina or a mixture of these prepared
from any mineral or otherwise may be used; the liquid is then thoroughly stirred
and mixed, and a further quantity of lime or its carbonate is added until the
phosphate or the alumina is precipitated or separated in a state of minute division
so as to act like the silica, as herein-before described; the liquid is afterwards
filtered and treated with animal charcoal.
If color is not an object the treatment with animal charcoal may be omitted.
The sweet liquid or syrup having been treated as herein-before described is next
concentrated in the usual manner, when however the desired degree of concentration
is reached the syrup is not cooled in the ordinary slow manner by allowing it to
stand in tanks or other vessel subjected only to ordinary atmospheric conditions,
but it is cooled as rapidly as is conveniently possible. For this purpose it is passed
through apparatus made like any suitable kind of surface condenser, the surface
•

page_text: thereof being cooled by a current of cold water proceeding by preference in an
opposite direction to the syrup. The cooling surface should contain about 200 square
feet for each inch of area of the discharge cock, supposing the syrup to descend a
depth of 20 or 25 feet, at any part of which depth the cooling apparatus may be
placed, and to be filled into puncheons or other vessels for storing or conveying it
by such discharge cock at the bottom.
A general arrangement of apparatus which we prefer to adopt where convenient
is shown in the accompanying explanatory Drawing, which is a vertical sectional
diagram. The cooling apparatus A consists in this example of a casing formed with
a compartment at a top, into which the syrup is led by a pipe B, and with a com-
partment at the bottom from which the syrup flows off by a pipe C; these top and
bottom compartments are connected by vertical tubes traversing the middle or main
compartment, and in this compartment water entering by the pipe D and passing
off by the pipe E exerts its cooling action on the outsides of the tubes through which
the syrup descends.
.
The cooling apparatus A is situated below a cistern F, into which the syrup is
transferred from the concentrating pan, and with which cistern it is connected by
the pipe B, so that the syrup may flow by gravitation through the cooling apparatus A
whenever the discharge cock G below is opened, but where sufficient height for
arranging the apparatus in that manner is not available the syrup may be pumped
or otherwise forced through the cooling apparatus at a rate due to a pressure of 15
or 16 pounds per square inch. The rapid cooling of the syrup has the further
advantage of preventing a darkening of color which takes place when the syrup is
cooled slowly.
Having thus particularly described our said Invention, and the manner of per-
formning the same, we have to state that we do not restrict ourselves to the precise
details herein described or delineated, but that what we believe to be novel and
original, and claim as the Invention secured to us by the herein-before in part recited
Letters Patent is,-
1. The making of clear bright syrups from the residual sweet liquids or syrups
obtained in manufacturing or refining sugar, the sweet liquids or syrups being
treated with a solution of a suitable substance, such as an alkaline silicate or a
soluble phosphate, or a salt of alumina, which substance is subsequently precipitated
and with impurities removed by filtration, whilst the syrups are cooled rapidly
after concentration, substantially as herein-before described.
2. The making of clear bright syrups fiom suitable sweet liquids or syrups, and
preventing them from becoming dim or turbid by rapidly cooling them after con-
centration, substantially as herein-before described.
3. The making of improved syrups from residual sweet liquids or syrups by
treating such liquids or syrups with a solution of a suitable substance, such as an
alkaline silicate, or a soluble phosphate, or a salt of alumina, which substance is
subsequently precipitated and with impurities removed by filtration, substantially
as herein-before described.
In witness whereof, we, the said Hugh William Walker and Thomas Law
Patterson, have hereunto set our hands and seals, this Fifth day of March,
in the year of our Lord One thousand eight hundred and seventy-seven.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
HUGH W. WALKER.
T. L. PATTERSON.
(L.S.)
(L.S.)