CERTAIN IMPROVEMENTS IN THE MANU- PACTURE OF SUGAR
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
COWPER, of Southampton Buildings, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fourteenth day of
November (One thousand eight hundred and forty-nine), in the thirteenth year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Charles Cowper, my exors, admors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Charles Cowper,
my exors, admors, and assigns, or such others as I, the said Charles Cowper,
my exors, admors, and assigns, should at any time agree with, and no others,
from time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, and in the Islands of Guernsey.
Jersey, Alderney, Sark, and Man, and also in all Her Majesty's Colonies and
Plantations abroad, the Invention of "CERTAIN IMPROVEMENTS IN THE MANU-
PACTURE OF SUGAR," communicated to me by a certain Foreigner residing

page_text: abroad; in which said Letters Patent is contained a proviso that I, the said
Charles Cowper, shall cause a particular description of the nature of the said
Invention, and the manner in which the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in Her said
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, as
in and by the same, reference being thereunto had, will more fully and at
large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Cowper, do hereby declare that the nature of the said Inven-
tion, and the manner in which the same is to be performed, are fully
described and ascertained in and by the following statement thereof, reference
being had to the Drawings hereunto annexed, and to the figures and letters
marked thereon, that is to say :-
The Invention relates to improvements in removing the impurities and
obtaining the sugar from cane juice, beet-root juice, solutions of raw sugar,
and other saccharine liquids. The processes hitherto in general use for ex-
tracting and manufacturing sugar have almost all been fundamentally the same.
Various modifications and improvements have been introduced into the details,
but the same difficulties have still remained to be overcome.
The present
Invention, on the contrary, is not only entirely new but is adapted to obviate
the injurious alterations of the sugar introduced by the common processes, and
to preserve the sugar pure, and to obtain it in larger quantity that it is now
obtained by the common processes. In examining into the different operations
in the manufacture of sugar, it will be seen that the object which has been
kept in view in the addition of lime in the defecation of the juice has been to
saturate the acids contained in the juice, and to facilitate the formation of
scum. But for this purpose the juice is boiled with the lime, and the following
inconveniences result: - Firstly, a great alteration of an azotised matter
whose decomposition produces the greater part of the ammonia which is
disengaged, whilst it is converted into a brown substance which combines
with the lime, and is dissolved in the juice. Secondly, the combination of
a portion of the lime with the sugar, which combination becoming insoluble
at a temperature of two hundred and twelve degrees of Fahrenheit's ther-
mometer, may be removed in the scum, thus causing a loss of sugar. Thirdly,
the alteration of an albuminous matter, which, uniting with the lime, pro-
duces a viscous stringy matter, which hinders the crystallization of the sugar.
Fourthly, the alteration of the sugar itself, which, under the influence of

page_text: the different matters contained in the juce and the temperature to which it is
exposed both in the defecation and in the following operations, becomes
uncrystallizable and acquires a brown colour which it is difficult to remove.
Fifthly, the alteration in the colouring matter, which having become green.
under the influence of the lime, acquires a brown colour, which deepens
gradually until it acquires the characteristic tint of molasses and raw sugar.
Of all the faults inherent in this method of manufacture, the one which.
has principally attracted attention hitherto is that of leaving in the sugar a
certain quantity of lime; although it had been found that animal charcoal was.
capable of removing this portion of lime, various attempts have nevertheless.
been made to precipitate it by various re-agents, such as sulphuric acid, alum,.
sulphate of alumina, carbonic acid, stearic acid, &c., it being supposed that
the causes of alteration might thus be removed, or that the quantity of
animal charcoal required might be diminished. These attempts have not
succeeded, as might have been expected, beccuse the alterations above men-
tioned have previously taken place, and, by precipitating the lime which was
in combination with the brown and viscous matters above mentioned, and to
which it gave fluidity, those matters are set at liberty and dissolved in the
juice, to which they communicate color and viscocity, and often hinder the
crystallization. On account of all these alterations the quantity of lime has
generally been limited to as small a quantity as possible. The object of the
present Invention is to act directly on the impurities of the juice, both organic
and mineral, so as to render them insoluble, preserving them at the same time.
from all the alterations above mentioned, and leaving the sugar uninjured in
solution in the water of the juice. By this means loaves of white sugar may
be produced immediately from the juice, without the necessity of first pro-
ducing a raw sugar and then refining it. To obtain these results I take
advantage of the property possessed by lime and certain calcareous salts under.
the influence of heat, of rendering insoluble the organized tissues of vegetables -
and certain other organic matters, and at the same time I prevent the altera---
tion of the different matters by regulating the temperature in a proper manner...
In consequence of this mode of proceeding the injurious action of the lime.
is obviated, and, instead of reducing its proportion to a minimum, as in,
the ordinary system, it may be used in large quantity with great, advantage...
The operation is performed in the following manner:-The juice having been..
obtained in the ordinary way from the canes, or from beet root or. other saccha
rine substance, the temperature is raised to from 120° to 167° Fahrenheit,.
according to the temperature of the atmosphere, the juice being, heated. most.

page_text: in cold weather. Lime previously slaked and sifted is now added in sufficient
quantity to saturate all the foreign matters capable of being coagulated by it.
The proper quantity can only be ascertained by experiment, as it varies with
the nature, the degree of maturity, and the state of preservation of the saccha-
rine vegetable, and even with the nature of the soil on which it is grown.
Thus, for beet root this quantity of lime may vary from fifteen to fifty pounds
weight for each hundred gallons of juice. The indications of the operation
being properly performed are the absence of any ammoniacal smell, a pale
yellow colouring of the juice, and a very decided alkaline taste, which almost
entirely overcomes and masks the taste of the sugar. After the mixture has
been well stirred it is heated to 185° or 194° Fahrenheit, taking great care
not to heat it to the boiling point. The alterations which take place in the
common process do not occur at the temperature above stated, and conse-
quently there is no disengagement of ammonia. The foreign matters in the
juice are now entirely coagulated, one portion risés as a scum and the
remainder precipitates to the bottom of the vessel. The clear liquor is now
drawn off and the skimmings pressed to obtain the liquor from them. If the
lime could be added exactly in the proper proportion to precipitate only the
foreign matters it is evident that the sugar alone would remain dissolved in
the water, together with the scluble salts contained in the juice; but as in this
operation the sugar and the foreign matters have both an affinity for the lime,
a large portion of the sugar combines with the lime, forming a saccharate,
which consequently indicates that the quantity of lime is sufficient, and forms
the characteristic test or indication of the completion of the reaction. It now
only remains to separate the sugar from this combination, and for this purpose
I employ one of the various re-agents known to be capable of precipitating
lime; and I prefer to employ carbonic acid on account of its easy and
economical production, and because it exerts no injurious action on the sugar.
It is conveniently produced by the combustion of charcoal or other species of
carbon, and, after having been washed by passing it through water in a
purifying vessel, it is blown into the juice. The lime combines with the
carbonic acid and precipitates in the state of carbonate when it is saturated,
which is easily ascertained; the liquid is boiled for some minutes to expel the
excess of carbonic acid, and thus to destroy the bicarbonate of lime which will
have remained in solution. It is then filtered and concentrated in the usual
imanner, and the juice thus treated does not become coloured by the evapora-
tion, and does not form any incrustation on the pans, but furnishes a syrup of
sufficient purity to be immediately converted into loaves of pure sugar of good

page_text: taste, and at once fit for the market, without requiring to be refined. These
loaves may be called No. 1 to distinguish them from those made in the subse-.
quent part of the process. If a still finer description of sugar is required
the syrup is filtered a second time, when by concentration it has acquired
a specific gravity of about 1.23 (distilled water being 1.00). It having been
observed that defecated juices retaining a certain quantity of lime did not
become coloured so rapidly by exposure to air as ordinary juices, it
has been proposed to boil the juice with lime in the proportion of about
one and a half per cent. of the weight of the juice, for the purpose of conduct-
ing the greater part of the operations under this influence, and also with the
view of diminishing the quantity of animal charcoal required, after which it
was proposed to separate the lime by a current of carbonic acid gas. But
this process would be as vicious in practice as it is irrational in theory, for the
foreign matters contained in the juice would undergo the alterations above
mentioned under the influence of the lime and the boiling; moreover, the
lime thus retained in the juice would form much more considerable incrusta-
tions than are formed by the ordinary juice. Besides these inconveniences
the coagulation of the saccharate of lime, which would inevitably take place in
these circumstances, would form deposits on the evaporating vessels and
entail the destruction of the sugar. The drainings or green syrups which
drain out of the loaves of sugar made by my improved process, as above
described, are sufficiently pure to be concentrated again and converted into
loaves No. 2, of nearly equal quality to those of the first crystallization.
However, as these syrups contain the soluble salts of the juice, and also some
vegetable matters which have escaped the action of the previous operations on
account of the dilute state of the solution, I add to them a fresh quantity of
lime proportionate to these matters, and then a quantity of silica and alumina
to combine with the salts of potash and soda and render them insoluble. The
silica and alumina are contained in a suitable state and proportion in various
plastic clays and siliceous loams. The following is the mode of operating :-
The syrups are diluted with water to a specific gravity of from 1-07 to 1.16,
and are heated to a temperature of one hundred and forty degrees of Fahren-
heit's thermometer. The lime is then added. In general from twenty to
thirty pounds of slaked line will be found sufficient for one hundred gallons of
the syrup; but this quantity will of course vary with the nature of the original
juice. The mixture is well agitated, and there is then added from two to four
pounds of clay or siliceous loam, previously mixed up with water into a sort of
cream.
The mixture is again agitated and the temperature raised from 140°

page_text: to 176° Fahrenheit, after which the lime is saturated by a current of carbonic
acid gas, as already described for the first juice. The liquor is now filtered
through animal charcoal, which removes the various impurities. This mode of
treatment is applicable to syrups formed by dissolving raw sugar for the purpose
of refining, and also to the purification of the inferior products, the molasses,
&c., which result from the ordinary processes. The drainings or green syrups
from the loaves No. 2 may be converted into granulated sugar No. 3, by
concentrating them and pouring them into vessels in which they crystallize
completely after twenty-four or thirty-six hours. As the sugars thus made do
not retain any foreign taste, and are bleached or whitened with great facility,
they may be at once converted into loaves No. 3 without redissolving in water,
clarifying, and evaporating, but simply by mixing them in proper proportion with.
the drainings from the loaves No. 1, heating the mixture to 185° Fahrenheit,
and pouring it into the moulds. The loaves thus obtained are whitened by
the ordinary processes. By this series of operations, white sugar fit for the
market is obtained successively even to the end of the process from cane juice,
beet-root juice, or other saccharine juices, without the necessity of refining.
The process is also applicable to the saccharine vegetable itself, either in the
state of pulp or when operated upon by maceration in water. It is important
to observe that the above-described system of operations no injurious effect is
to be apprehended either for the workman or the apparatus, nor is there any
danger of leaving in the sugar any poisonous substance from carelessness in
conducting the operations, as might be apprehended if poisonous substances
had been employed, such as the salts of baryta, lead, &c.
DESCRIPTION OF THE APPARATUS FOR PRODUCING CARBONIC ACID GAS AND
FORCING IT INTO THE SOLUTION OF SUGAR.
Figure 1 of the Drawing hereunto annexed is an elevation, and Figure 2
a plan of the apparatus. B is a double-acting blowing cylinder or pump
worked by the steam engine A, or by any other motive power. This blowing
cylinder drives a current of air into the close stove or furnace D by means of
the pipe C¹ connected to it at the lower part, and on a level with the grate.
From the top of the stove proceeds another pipe a which conducts the
products of combustion into a close vessel F about half full of water, into
which the extremity of the pipe is immersed. This water is intended to
deprive the gas of its impurities. To the upper part of this vessel is connected
another pipe h for conducting the gas into the pan G, Figure 3, in which the
juice is to be operated upon by the carbonic acid. The tube h is provided

page_text: with a cock and descends into the pan, making a spiral turn ; which
diminishes in diameter from the upper part towards the bottom when the pan
is hemispherical, but is placed horizontally at the bottom in flat-bottomed pans
like that represented in Figures 3 and 4. The extremity of this tube is
closed by a screw plug, and it is perforated with a number of small holes
placed alternately on each side. The number and diameter of the holes are
such that the sum of their areas is equal to the section of the tube itself,
taking care when the holes are not all on the same level to make the upper
ones smaller than the lower ones, otherwise too much gas would pass out from
the upper holes and too little from those immersed deeper in the liquid. To
obtain carbonic acid by means of this apparatus a fire is lighted with a
mixture of well-burnt coke and charcoal in the stove D, the openings are
closed, and the blowing machine set in motion. The combustion being kept
up by the current of air, forms carbonic acid, which becomes purified by
passing through the water in the purifying vessel F, and thence passes into
the pan G into the midst of the liquor, which it agitates in every direction.
It immediately forms on the surface an abundant froth or foam, which after a
short time entirely disappears, leaving uncovered a turbid muddy liquid which
serves as an indication of the completion of the operation. The gas is very
hot as it issues from the stove D, but it is partially cooled by the pipe being
surrounded by a vessel E filled with water, which acts as a refrigerator and is
provided with a supply of cold water for that purpose. This refrigerator is
farnished with a cock c on the pipe which admits the water, and which may
also be placed in communication with the purifier F by the pipe d; it is also
provided with a pipe 6 for the escape of the water, and a cock e for emptying
the refrigerator. For the purpose of moderating the intensity of the fire, an
outlet pipe with a cock C is placed on the pipe which connects the blowing
machine to the stove, by means of which a portion of the air may be allowed
to escape. A safety valve s is also placed on the purifer F, to obviate any
chance of accident from the holes at which the gas escapes becoming
obstructed. The purifer F is also provided with two cocks, one of which, f,
serves for regulating the level of the water, while the other, g, serves for
emptying the vessel.
In witness whereof, I, the said Charles Cowper, have hereunto set my
hand and seal, this Eleventh day of May, in the year of our Lord
One thousand eight hundred and fifty.
CHARLES (L.s.) COWPER.

page_text: AND BE IT REMEMBERED, that on the Eleventh day of May, in
the year of our Lord 1850, the aforesaid Charles Cowper came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that purpose.
AND BE IT REMEMBERED, that on the Eleventh day of May, in
the year of our Lord 1850, the aforesaid Charles Cowper came before our.
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Enrolled the Eleventh day of May, in the year of our Lord One
thousand eight hundred and fifty.
Enrolled the Eleventh day of May, in the year of our Lord One
thousand eight hundred and fifty.