IMPROVED PROCESSES FOR DEFECATING OR CLARIFYING SACCHARINE LIQUORS WHICH INVENTION ALSO COMPRISES A COMPOUND FOR USE IN SUCH PROCES
Year: 1883

page_text: LETTERS PATENT to Henry Harris Lake, of the firm of Haseltine, Lako
& Co, Patent Agents, Southampton Buildings, London for an Invention of
" IMPROVED PROCESSES FOR DEFECATING OR CLARIFYING SACCHARINE LIQUORS
WHICH INVENTION ALSO COMPRISES A COMPOUND FOR USE IN SUCH
"
PROCESSES communicated to him from abroad by Henry A Hughes, of
Camden, New Jersey, United States of America
COMPLETE SPECIFICATION filed by the said Henry Harris Lake at the Office
of the Commissioners of Patents on the 9th July 1883.
HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings London "IMPROVED PROCESSES FOR DEFECATING OR
CLARIFYING SACCHARINE LIQUORS WHICH INVENTION ALSO COMPRISES A COMPOUND
FOR USE IN SUCH PROCESSES" communicated.to me from abroad by Henry
A Hughes of Camden, New Jersey, United States of America
This invention relates to improvements in processes for defecating and clarifying
saccharine liquors, and to a compound for use in the said processes.
The object of the said invention is to separate from the saccharine liquors all, or
the greater portion, of the matters therein contained, except sugar and water, this
process being commonly known as defecation and clarification. At the present
time four general methods may be recognized for accomplishing this result,
depending respectively upon the application of heat, upon the use of chemicals,
upon filtration, and upon galvanic or electrical action." This invention belongs
mainly to the second class, inasmuch as the processes. hereinafter described depend
chiefly upon the employment of certain chemical agents.
The said invention consists; in providing a mixture of sulphurous acid gas and
cream of lime for treating the saccharine liquor; (the said mixture I believe to act
both chemically and mechanically, inasmuch as there is contained considerable
quantity of free sulphurous acid gas in the compound when in the best condition

page_text: for use); in the process of treating the saccharine liquor with the said mixture in
the manner set forth; in the process of treating the saccharine liquor, subsequent
to the same being acted upon by the aforesaid mixture, with an aquous solution
of acid; in the process of treating the saccharine liquor with the aforesaid mixture
and the dilute acid solution and filtering while cold in the process of treating the
saccharine liquor with the aforesaid mixture and the dilute acid solution, then
heating and finally filtering; in the process of delaying fermentation in saccharine
liquors by treatment with the aforesaid mixture and the dilute acid solution, and
in the process of removing the sulphurous taste in sugar defecated by the aforesaid
or any other sulphur processes by injection of live steam.
According to the said invention the juice, after being expressed from the cane by
any well known means, is collected in a tank of suitable size, holding generally
about a thousand gallons. To it is added a mixture which is prepared in the
following manner that is to say ;-Fresh quick lime is slaked with water, so that
the resulting mixture has the consistence of a thick cream, which is conducted into
a vat or reservoir. In this vat is arranged a shaft, provided with radial arms
which carry beaters or paddles, and means are provided for rotating the said shaft
in the vat; which by means of a flue or passage entering at its upper portion,
communicates with a furnace suitably constructed for. burning sulphur, so that, by
means of the said connecting passage, the sulphurous acid gas, resulting from the
combustion of the sulphur, is led into the upper portion of the vat and above the
cream of lime therein. Suitable means are provided for drawing in the said
fumes, so that a constant current of sulphurous acid gas is caused to enter the vat.
The shaft and beaters being set in rotation, the liquid contents of the vat are
violently agitated, and at the same time the sulphurous acid gas is beaten into
and caused to mingle with the same. The process of mixing the gas and cream of
lime is continued until the liquid assumes a clear, yellow color and gives when
tested with litmus test paper, a strongly acid reaction; this.acid reaction is essential.
The liquid also has a clearly perceptible sulphurous smell. The exact length of
"time for beating and allowing the passage of sulphurous acid gas in the cream of
lime cannot definitely be stated, but for all practical purposes it will be sufficient
if the liquor presents the characteristics before stated, when it will be ready for
use. It is preferable to make the cream of lime of as thick a consistence as possible,
while at the same time not so thick as will prevent the free working of the beaters.
It will be noticed also that shortly before the cream of lime becomes impregnated
with sulphurous acid gas, so as to reach the condition before described, its tempera-
ture becomes elevated to a degree almost enough to scald the naked hand.
After the liquid reaches the before stated condition, further continuation of the
process depends upon the state of the cane juice to be treated; thus, if the juice is
pressed from frost bitten, soured or otherwise damaged cane, so that the juice is
more than normally sour, it is advisable to continue the impregnation of the cream
of lime for from ten to twenty minutes longer, or generally to bring the liquor to a
higher degree of concentration, strength and acidity than in the former case.
To the cane juice collected in the tank, I add such a proportion of the sulphurous
acid and cream of lime combined as before stated, as will render the contents of the
tank slightly turbid. No definite proportion can be stated nor is it necessary to do
so for practical purposes. The test of turbidity is sufficient and itself determines
the amount of the mixture to be added. It is important to note however, that the
condition of the juice hastens or delays the turbid appearance. Thus if the juice
'is normally neutral, a very small proportion of. the mixture will render it turbid.
On the other hand, if the juice is acid, the turbid condition will be delayed in
proportion to the acidity.
".
The effect of adding the mixture to the juice is to cause a precipitation of the
coloring matters and other impurities, excepting the mucilage or gum.
This effect is best produced when the mixture is used immediately after, produc-
tion, as it should be.
3
The mixture deteriorates if allowed to stand in air. If it is necessary to keep the

page_text: mixture for any length of time, it should be hermetically sealed up in an air tight'
vessel with a solution of sulphurous acid in water, on the top of which mixture it
will float.
The precipitation takes place immediately, and the juice may be at once pumped
or otherwise removed from the tank to the defecators, where it is heated and the
scum removed in the usual manner. The principal defecation takes place in the
tank, as already described, and a still further defecation occurs through the action...
of heat in the defecating vessels. From the defecators the juice passes to the
evaporators, thence to the vacuum pan, then to the coolers or mixers, and finally to
the centrifugal machine; the course of the juice after leaving the defecators being
the same as it ordinarily follows when known processes of defecation are employed.
In order to remove the sulphurous flavor of the syrup which comes from the centri-
fugal machine
find it advantageous to collect the said syrup in a suitable tank
provided with perforated steam pipes, through which live steam is injected into'
the syrup. This injection' of steam is continued until the sulphur taste is no longer
apparent. The sugar resulting from this process contains considerable of the
natural gum, and although quite light in color, has a small grain and is not easy to
purge in the centrifugal machine. It is however an excellent marketable product;
and gives a high polaroscopic test."
Returning now to the defecated juice in the tank, I find that a somewhat better
sugar may be produced by continuing the process in the following manner, that is:
to say,
:
I prepare a weak solution of sulphuric acid, preferably about one volume of acid-
to four volumes of water. I do not limit myself to sulphuric acid, as I have found
that other acids, notably hydrocloric and acetic acids, when in weak solution, will
accomplish substantially the same result. It is desirable, however, that the
strength of the acid solution should not be greater than is indicated by the propor-
tions of sulphuric acid and water before stated.
This acid solution is to be added to the defecated juice in the tank preferably in
the proportion of 500 cubic centimeters of acid solution to 1000 gallons of juice..
I have found this proportion to work well with sorghum juice.
It can be exceeded probably to a considerable extent without danger though'
with no perceptible advantage in results. Care, however, is to be taken not to add
too much of the acid solution as the consequence might be to invert the sugar.
The effect of the acid solution upon the defecated juice is to throw down the
gum or mucilage, some of which is actually precipitated immediately, and all.
eventually, if the juice is allowed to stand long enough for the light flocculent.
material to gravitate to the bottom.
The success of the operation is at once manifested by the rising of sulphurous"
fumes from the juice, the odor of which is plainly perceptible.
.As the deposition of the light, mucilaginous material requires some delay, it is
better in order to save time to separate it by means of a filter press of any suitable.
construction, from which the filtered juice emerges clear. It will be seen that this
process gives a cold defecation and thus accomplishes a result of great value and
importance. A slightly better grade of sugar can be made however by conducting.
the juice to the defecating vessels and there heating it nearly to the boiling point.
before passing it through the filter press, but this warming of the juice is not
essential to the production of excellent sugar by the aid of my process as
described.
"
In the cold process as I have described it, the juice passes from the filter presses:
directly to the vacuum pan, thus entirely dispensing with defecators and clarifiers.
Care, however, must be taken that the filter press is properly worked, and that
none of the scum is allowed to mingle with the juice.
In the warm process the juice passes as already stated from the defecators to the
filter press, and thence to the clarifiers. So far as the relative advantages of the
two processes are concerned, the cold process requires greater care in operation and.
produces almost, if not equally, as good a grade of sugar and does away with

page_text: defecating and clarifying vessels and the skilled labor and expense attendant upon
their use. The warm, process on the other hand requires less care in its general
operation but involves the use of defecators and clarifiers to compensate for such.
lack of care, and produces a grade of sugar which a very experienced eye only
would class as of better grade than that made by the cold process.
When treated by either process the course of the juice after leaving the vacuum
pan is the same as already set forth. The resulting sugar is free from gum, or
very nearly so, and is generally of considerably better quality both in grain, color
and test than that made without the use of the weak acid solution.
It is well known that cane juice after being expressed will ferment in a very
short time and invertion of the sugar is the result, so that it is available only for
the manufacture of alcohol or poor molasses; an important advantage of this
invention is that after the juice is treated with the sulphuretted lime mixture and
the acid solution as before described, it will remain unchanged and no fermentation
will take place as long as the sulphurous fumes continue to be emitted from it
whether it be exposed to the air or not. I have kept such juice exposed to the.
air in a warm room for three months without detecting perceptible deterioration
in it.
The foregoing process I have described as applied to the juice of the sorghum
plant but I have found it to be applicable equally well to the ordinary sugar cane
and to the manufacture of molasses sugars.
It is equally applicable to the improvement of any raw sugars, these being
dissolved in water prior to the addition of the lime mixture and acid solution.
It will be observed from the foregoing that in the processes described the liquor
remains acid, that is, gives, an acid reaction to the test paper throughout, and in
this respect the said processes differ materially from ordinary lime or lime and
sulphur processes wherein the liquor is kept neutral. This acidity I remove either
wholly or in great measure by the boiling of the liquor in the evaporators and
vacuum pans.
Having thus fully described the said invention as communicated to me by my
foreign Correspondent, and the manner of performing the same, I wish it.
understood that I claim
-
First The defecating compound or mixture for saccharine liquors, herein
particularly setforth, consisting of cream of lime and sulphurous acid, mingled and
combined until the said cream of time is completely saturated with sulphurous
acid, substantially as described.
Second The process of defecating saccharine liquors, consisting in adding to the
juice the sulphuretted cream of lime compound, herein setforth, prior to heating.
the same in defecating vessels, substantially as described.
Third The process of defecating saccharine liquors consisting in adding to the
juice, the sulphuretted cream of lime compound herein set forth, and a dilute
aqueous solution of acid, substantially as described.
Fourth-The process of defecating or clarifying saccharine liquors by adding to
the juice the sulphuretted cream of lime compound herein setforth, and afterwards
a dilute aqueous solution of acid, and then filtering the juice while cold,
substantially as described.
Fifth The process of defecating or clarifying saccharine liquors consisting in
adding the sulphuretted cream of lime compound herein setforth to the juice and a
dilute aqueous solution of acid, then heating the said juice in defecating vessels,
and finally filtering the same, substantially as described.
Sixth The method of delaying fermentation in saccharine liquors, consisting in
adding to the said liquors the sulphuretted cream of lime compound herein set-
forth, and a dilute aqueous solution of acid, substantially as described.
Seventh-The process of removing the sulphurous taste or odour of syrups
defecated by a sulphur process, consisting in injecting live steam into the said
syrups, substantially as described.
Eighth The process of defecating or clarifying saccharine liquor, consisting in

page_text: adding to the said liquor an acid solution or solutions whereby the said liquor is
rendered acid, and finally removing the said acidity either wholly or in part by
boiling the liquor, substantially as described.
In witness whereof I the said Henry Harris Lake have hereunto set my hand
and seal this ninth day of July in the year of our Lord One thousand eight
hundred and eighty three.
HENRY H LAKE (L.S.)