IMPROVEMENTS IN THE MANUFACTURE AND REFINING OF SUGAR
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DANIEL
TOWERS SHEARS, of Bankside, in the County of Surrey, Copper Merchant,
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 Seventeenth day of
October, One thousand eight hundred and fifty, in the fourteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Daniel Towers Shears, my exors, admors, and assigns, Her especial
license, full power, sole privilege and authority, that I, the said Daniel
Towers Shears, my exors, admors, and assigns, or such others as I, the said
Daniel Towers Shears, my exors, admors, or 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 in all Her said
Majesty's Colonies and Plantations abroad, the Invention of "IMPROVEMENTS
IN THE MANUFACTURE AND REFINING OF SUGAR," communicated to me from
abroad); in which said Letters Patent is contained a proviso that I, the said
Daniel Towers Shears, shall cause a particular description of the nature of the
said Invention, and in what manner the same is to be performed, by an instru-
ment in writing under my hand and seal, to be inrolled in Her Majesty's

page_text: 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
Daniel Towers Shears, do hereby declare that the nature of the said Inven-
tion, and in what manner 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 :-
My first improvement consists in the employment in the interior of the
vacuum pan (used for sugar) of a machine which I call a rouser or a dis-
placer, see Figures 1, 2, 3, 4, 5, and 6, and which use for the purpose of
stirring or displacing the sugar in the pan, or to mix with the sugar such
liquor as may be introduced into the pan to facilitate the discharge of the sugar
from the pan when therein boiled to dryness, a state to which I reduce
saccharine solutions either by boiling them in vacuo or at a low temperature
under atmospheric pressure, or when I reduce it to such a state of dryness
that it cannot be discharged conveniently in the ordinary way. The said
displacer or rouser may be of any form or description that may be found
convenient for effecting the object in view, but I employ in preference one or
other of those herein-after described, as rouser No. 1, No. 2, and No. 3.
Rouser No. 1, shewn in Figures 3 and 4, is in preference made with two or
more sets of arms in the shape of a cross A, A, fixed on the shaft B working
in the interior of the pan; to these arms are fastened the vertical bars a, a,
composed of hard wood or metal; or they may be placed in any other position
most convenient for moving or stirring the sugar. The arms A, A, should
be made to extend as near to the sides of the pan as convenience will admit,
and should by preference descend into the pan to about two thirds from the
top, and so be arranged that they may by preference revolve in the pan at
about one third from the bottom of the pan. The tubes for the glasses, see
Figure 7, and for the proof stick, should be so fitted that they may not inpede
the movement of the said arms A, A. The shaft B descends through a stuffing
box at the centre of the top of the pan a, Figure 1; its lower end works in a
bearing b, Figure 1, provided for it. This shaft is fitted at the exterior with
suitable apparatus to turn it at about the speed of twenty revolutions per
minute, more or less, as may be found convenient. The object and intention of
the said rouser is, by revolving in the interior of the pau, at a convenient moment
to displace the sugar boiled to dryness, and thereby cause the expulsion of the
sugar in a dry state, or cause it to mix with the liquor that may be introduced

page_text: into the pan by the pipe f, for the purpose of reducing the dry sugar without
crystallizing the said liquor, and without redessolving the sugar to a state that
will admit of its being discharged in the ordinary way.
My second improvement consists in the introduction into the pan, after the
sugar has been therein boiled to dryness (or to such a state of dryness that it
cannot be discharged from the pan in the ordinary way), of a quantity of thick
liquor, and in the employment of the said liquor, not for the purpose of
crystallizing it, but with a view to mix it with the aforesaid dry sugar and to
reduce it (the sugar) to a state that will admit of its being discharged from the
pan with facility. In respect to the aforesaid rouser, I would remark that
although it may be employed in any way that may be found convenient,
yet I prefer to employ it in one or other of the methods herein-after
described.
.
The first mode of employing rouser No. 1, Figures 3 and 4, is this, namely:→
The steam or heating medium of the pan is stopped (care being taken to
continue the vacuum) when the sugar is boiled to sufficient dryness, which the
proof stick will shew by its bringing no more sugar from the pan, or it may be
ascertained in any other way. A stream of cold water is then made to flow
through the steam pipes, in order to cool them and to prevent the sugar from
concreting about them. The hole for discharging the sugar (which should be
made as large as possible) is then opened, the vacuum having been previously
destroyed, and rouser (No. 1.) is put (at first) in slow motion to displace and
expel the sugar.
Second mode of employing rouser No. 1, Figures 3 and 4, and method.
of employing the liquor already referred to.-The sugar having arrived at
sufficient dryness, the steam is (by preference) stopped, the vacuum being all
the while preserved; a quantity of thick liquor or syrup, of a density (by
preference) of thirty-six degrees of the saccharometer of Beaumé cold, is then
introduced into the pan, by preference, at the bottom; so that it may rise
through the body of the sugar, which it will generally do while the vacuum is
on. The quantity of liquor introduced should be sufficient to enable the sugar
when mixed with it to run freely, but as thick as possible from the pan. No
rule can be laid down for correctly ascertaining the necessary quantity, but
about enough will have been admitted when seen to rise to the surface
of the sugar in the pan (which it will generally do in vacuo if not
prevented by some defect in the mode of conducting the operation).
The rouser is then made to turn slowly at first, the speed to be increased
afterwards according to the judgment of the operator. The vacuum should be
(by preference) kept on during this part of the operation; but it will not be
necessary when liquor is employed,. as aforesaid, to cool the steam pipes. The

page_text: steam may then be weakly applied for the purpose not of crystallizing the said
liquor, that that be cautiously avoided, but for that of aiding to mix the sugar
(about the pipes) with the liquor, constant experience having shewn that the
moment saccharine solutions are crystallized, weakness is engendered in a
large portion of the saccharine, which goes off in a state of syrup. It is most
escential for obtaining good subsequent results that the aforesaid liquor be not
crystallized while employed as aforesaid, and that it be preserved as much as
possible in all its original strength, in order that it may subsequently be also
boiled to dryness. As soon as the amalgamation of the dry sugar and the
liquor aforesaid is sufficiently effected to admit of the pan being discharged,
the vacuum should be destroyed and the contents of the pan let out. The
liquor which comes from the aforesaid sugar should (by preference) be in the
subsequent operations mixed with raw sugar, and after having been prepared
in the usual or any other way, boiled to dryness and treated as aforesaid.
Rouser No. 2, shewn in Figures 1 and 2, consists of a portion of a screw C
fixed at the lower end of the shaft B, and is revolved with it in a similar
manner described for Figures 4 and 5. The screw C is encased by a cylinder
d, open at both ends, standing vertically in the centre of the pan, and kept in
its position by the arms e, c, or other suitable contrivance. The dry sugar
having been saturated with the liquor aforesaid, the screw C is made to
revolve with the shaft B, and elevates the sugar from the bottom to
the top of the cylinder, whence it descends to be again elevated by the
screw. The elevation is continued till the whole of the sugar has acquired
the desired consistency, and is then discharged. Rouser No. 3 is shewn in the
Drawing as Figures 5 and 6, and consists of two or more sets of inclined
arms or blades a, a, fixed on the shaft B, and made to revolve with it, as before
described for rouser Nos. 1 and 2, the operation being continued till the
sugar is of the required density for discharging it.
Another improvement consists in the fitting and in the employment (in the
interior of the vacuum pan, near the bottom) of a pipe or pipes perforated
with small holes to allow the escape into the sugar of air, when introduced
into the pipes. Having found it to be advantageous and to aid crystallization
(when boiling raw materials in vacuo) to introduce cold air into the liquid
(after having destroyed the vacuum), I employ the aforesaid pipe for this
This I do after having boiled the liquid in vacuo to the density (by
preference) of from thirty-four hot to thirty-eight Beamé, which density the
boiler, from his experience, will easily ascertain.
purpose.
and the vacuum destroyed, the temperature of the
The steam being kept on
liquid, which I prefer to
be kept at from one hundred and seventy to one hundred and ninety while
boiling it to sugar, is regulated by the cold air admitted at will.

page_text: In respect to the first and second parts of the Invention, I claim the appli-
cation to vacuum and other pans of machines I call rousers, for stiring or
mixing the sugar in the pans. I also claim the methods herein described for
facilitating the discharge of sugar from vacuum pans or other vessels.
I also
claim the use and application of cold air for assisting the crystallization of
saccharine solutions in the vacuum pan as described.
The third part of my Invention I effect in one or other of the following
methods. It consists in converting beetroot or other saccharine juices into
loaf or other description of sugar, generally known as refined sugar, at one
operation, instead of first making it into raw sugar and then refining it, as at
present practised. I adopt the following methods :-
First method. The juice being boiled to sugar I put it to crystallize in any
convenient way, but by preference I employ for that purpose vessels of the
largest size that can be conveniently used. When crystallized I extract the
syrup by the centrifugal or pneumatic processes, or any other convenient mode.
The dry sugar is then reduced by the addition (in the heaters or other con-
venient vessels) of liquor or other liquid to the consistency required for
placing in the moulds or forms, where I then allow it to set sufficiently hard
to enable the moulds to be transferred and fixed in a horizontal position in
centrifugal apparatus, or vertically in pneumatic apparatus, for extracting the
syrup. The mode I prefer to adopt is as follows:-I place the moulds or
forms with their apices outwards, resting in circular holes made in two con-
centric cylinders or rings. The inner or larger hole is edged with caoutchouc
or other flexible material, which prevents the syrup from leaking or passing
between the moulds and orifices. When centrifugal motion is given to the
cylinders or rings I place the syrup for washing the sugars in the inner
cylinder. The syrup is forced through the moulds by the centrifugal motion
given to the apparatus. The syrup extracted is received in an external case.
The moulds may then be taken out and the sugar dried in the usual way. Or
I prefer allowing the moulds to remain in their position, taking care to
exclude the atmosphere from the interior of the machine and causing
heated air to flow in to it, taking care also to adjust the speed of the
machine as may be found most convenient.
My second mode of making loaf sugar from beetroot and other saccharine
juices is as follows:-The juice having been purified and crystallized in any man-
ner not calculated to produce loaf sugar, I reduce the sugar to the consistency
and temperature needful for loaf sugar, and I then transfer it to loaf or other
moulds convenient for producing what is called refined sugar, and I then
treat the sugar in the ordinary way followed for making refined sugar. By the

page_text: . aforesaid modes of operating superior loaf instead of raw sugar will be
obtained directly from the juice, and the necessity of first making.it as here-
tofore into raw sugar, then refining it, by which much of the raw sugar which
was formerly converted into bastards and treacle will be avoided, and much
more refined sugar be obtained from beetroot and other saccharine juices
at one boiling. And I would state that this part of my Invention also
consists of employing centrifugal apparatus in refining sugar by placing
therein moulds, as above explained, with their smaller ends outwards, so that
the fluid from the moulds may be thrown off through the orifices at the
smaller ends of the moulds.
I claim in respect to the third part of my Invention the two methods
herein described, of making loaf sugar from beetroot juice or other saccharine
juices. I also claim the construction of centrifugal apparatus arranged suitably
for receiving moulds, so that their smaller ends may be outwards, as explained.
The fourth part of my Invention consists in purifying saccharine solutions by
means of the combination of an alkali and of an acid gas. I effect these objects
in the manner following, videlicet:-I employ in preference an alkaline mate-
rial composed of prepared lime and a West-Indian plant, "Wassama," or the
ingredient No. 1, specified in a Patent for England, granted to Charles
Richardson, Tenth September, One thousand eight hundred and forty-six, for
"Certain Improvements in the Manufacture and Refining of Sugar," or such
other alkalies and acid gases as may be found convenient. I dissolve either
of the aforesaid alkaline materials or ingredients by preference in cold water
to the density of about fifteen degrees Baumé's saccharometer. It is then
applied to the saccharine solution, which I prefer to be about the density of
thirty-two degrees Beaume cold, till it becomes strongly alkaline. This done,
and convey into the solution (either by means of a pump or other convenient
mode) a sufficiency of acid gas, and thereby form the combination referred to.
By preference I use carbonic or sulphurous acid gas to reduce the solution to
a very slightly alkalescent state. The gas should by preference be applied to
the liquid in a cold state. Now, in the absence of the clarifying materials re-
ferred to, employ any other alkali that may be suited to the purification of saccha-
rine solutions, and that will admit of the combination desired with an acid gas
in the solution. The solution should then be (by preference) boiled for a few
minutes, and the impurities allowed to precipitate before it is filtered; or it
may be clarified in any of the usual ways, then filtered. By allowing the
impurities to precipitate the use of blood may be entirely dispensed with, and
the filtration will proceed with facility. In order that the saccharine solutions
may be cold, which I prefer should be the case when the gas is applied, the

page_text: sugar to be operated on should by preference be kept while dissolving in as
thick a state as possible, so that the solution may be rendered cold by the
addition of cold water to reduce it to the required density to receive the gas.
I claim, as the fourth part of my Invention, the purifying saccharine solu-
tions by the introduction into them of an alkali or alkalies, and acid gas
or gases.
My fifth improvement consists in the methods herein-after explained of
purifying and discoloring West India molasses for making loaf or other refined
sugars. First, I mix with the water intended to melt the sugar about to be
clarified in the ordinary way a certain quantity of molasses, preferring (though
a quantity equal to the weight of the aforesaid sugar, or even more, may be
used) to employ for producing sugar of a superior quality a quantity equal in
weight to one half that of the said sugar. I reduce this mixture to a density
of about nine or ten degrees Beaume, then free it of acidity, purify, and
discolour it. For this purpose the ingredients No. 1 and 2, specified in a
Patent for England, granted to Charles Richardson, for Certain Improve-
ments in the Manufacture and Refining of Sugar,' dated Tenth September,
One thousand eight hundred and forty-six, may be employed, though the
ingredients prepared with Wassama' have been declared in the West
Indies to be far preferable. These ingredients having been dissolved as afore-
said in cold water to the density of about fifteen degrees Beaumé, the purifying
matter No. 2, above referred to, is mixed with the solution of molasses in the
proportion of about five pounds (dissolved in water) for every hundredweight
of molasses employed in solution with water. The saccharine solution is then
boiled for about five minutes, and the ingredients allowed to precipitate till
the liquid becomes clear. It is then drawn off, and employed to dissolve the
sugar intended to be refined. But before mixing it with the sugar, and after
having drawn it from the sediment, a portion of the ingredient No. 1 aforesaid,
sufficient to render the solution very slightly alkalescent, should be well mixed
with it. The portion of ingredient No. 2 may be decreased or augmented at
will to produce the color required. By reducing West India molasses, rhoar,
or other saccharine materials highly charged with coloring matter, to a thin
state, then clarifying the solution, the quantity of charcoal required for
discoloring it will be greatly diminished; and by mixing convenient portions
of molasses with sugar, as before mentioned, the combination of molasses-and
sugar cane with great facility and advantage be crystallized to dryness in the
pan, or loaf or other refined sugar, equal in quality to that produced from raw
sugar alone, will be obtained, and a quantity of refined sugar, nearly equal in
weight to the raw sugar employed, will be yielded at one operation.

page_text: I claim the reducing West Indian molasses, rhoar (or other saccharine
substances), to a thin solution, and purifying and treating them as described.
And I also claim the crystallizing to dryness of solutions of West Indian
molasses, rhoar, or such like materials, either individually or in combination
with each other or with raw sugar, by combining the evaporation after the
formation of the crystals.
My sixth improvement consists in the application and construction of
apparatus for regulating or keeping a uniform pressure of steam in the steam
spaces of vacuum pans, or other apparatus used for the manufacture of sugar,
or other purposes where steam or other expansive vapour is used as the heating
medium. This my Invention is also applicable to any other purposes where
a constant or uniform, or any determined pressure of steam or other vapour is
required.
I will proceed to describe the nature of my Invention, as follows:-The
pipe a (see Drawing, Figures 8, 9, and 10,) is for the admission of steam or
any other expansive vapour, of any pressure existing in the boiler or reservoir
to which it may be attached. The steam or vapour is allowed to pass through
the openings or steam ports b, b, when they are uncovered by the slide valve c,
through the pipe d, to the vacuum pan or other vessel in connection with
it. To the pipe d is attached a cylinder e, accurately bored out, into which
is fitted a piston capable of moving freely (steam-tight) in it. The piston f
is loaded (by weights g & h, or any other contrivance) to any pressure
required in the pipe d, or to the apparatus attached. The slide valve c will
allow the ports to remain open till the vapour in the pipe d exceeds the
pressure at which the piston f is loaded; it will then drive the piston f up the
cylinder e, simultaneously acting on the slide valve c by means of the rods j, j
and the lever i. This action of steam or vapour on the under side of the
piston will always keep the slide valve ports 6 so adjusted as to admit such
quantity of steam or vapour as shall keep an unvarying pressure on the vessels
or apparatus attached to the pipe d. Or, instead of the valve c, I may use the
valve as shewn in Figure 9. The valve consists of two pieces or portions of a
cylinder, with passages or openings made in them, attached to an arm.or
double lever b, and fitted to the cylindrical part of the valve seat c, which has
also openings or passages, or an opening or passage, made in it to admit or
exclude the steam or vapor; this valve is connected to the end of the lever K
by means of the lever d and rod j. Or, instead of the above valves shewn in
Figures 8 and 9, I may use the valve as shewn in Figure 10, which is a plate
or tumbler valve fitted into the tube or seat a, and attached to the end of the
lever K by means of the lever c and rod j.
b

page_text: I claim as the sixth part of my Invention the arrangement of apparatus
above described for regulating the stean for vacuum pans and apparatus
employed in the manufacture and refining of sugar.
I will proceed to describe the nature of my seventh improvement. I take
the expressed saccharine juice from the sugar cane or other substance, and
either pump it into the first boiler or pau A, see Drawing, Figs. 11 & 13,
or allow it to run in by its own gravity from a sufficient height to enable it to
overcome the pressure in the interior of the pan. The juice in the pan or
boiler A is boiled by the application of steam either direct from a steam
boiler; or I use the waste steam from high pressure engines for the purpose.
The juice in the first pan a is sufficient to extract all the latent heat in
the steam applied to it. The steam generated in the interior of the boiler or
pan A is then allowed to pass down the pipe x, through the passages into the
tubes of the next compartment or boiler B, Figs. 11 & 13, thence by a
similar set of passages into the boiler of the third boiler C, Figs. 11, 12,
13, and 14, to serve as heating medium for the second and third paus
B and C; or in case of this not being sufficient I admit a further quantity by.
the pipe a direct from the boiler. The juice in the boiler A is concentrated
to about ten degrees Beaumé, and is constantly drawn over to the second
boiler B, by the vacuum in the second pan, to the constant level of the pipe
connecting them. In the second pan I evaporate the juice to the density of.
about twenty-five degrees or twenty-seven degrees Beaumé, from thence it is
drawn by a pump to be filtered, if necessary, and is then returned into the
third pan or boiler C to be concentrated to the crystallizing point, as is usual.
by the ordinary methods at present in use. I do not cause any vacuum to be.
made in the first pan, but in the second and third, which I can regulate at
pleasure by the valves i, i.

page_text: steam from the juice in the first pan by means of the pipe x to the reservoir K.
C, pipe for conducting steam from the reservoir K to the second pan B.
d and e pipes for conducting steam from the reservoir K to the heating pipes
of the third pan C. f, g, h, pipes for connecting the second and third pans
B and C with the condenser y. i, i, valves for regulating steam and
vacuum. K, steam reservoir for supplying the steam of the first pan to the
second and third. 1, 1, dome from which the steam is led away through the
pipes a iu the direction shewn by the arrows ultimately to the condenser y.
m, m, valves to admit steam direct to the pans from the boiler when
necessary. n, valves 'for steaming out' the pairs. o, cock on the pan A, for
regulating the level in the two pans A and B. p, pipe for admitting juice to
pan A. 9, cock and pipe attached to pan B; for communicating with a pump
when filtration of the juice is required. 7, valve for discharging the crystalized
sugar from the third pan C. s, t, pipes for carrying off the condensed water
from the steam compartment of the paus A, B, C, through the condense
water box Su. u, the proof stick. v, vacuum valve. w, grease cocks.
a, pipes for conducting away the steam from the domes 1, 1. z, light and
sight glasses. y, the condenser, in which a vacuum is maintained by any
convenient method.
I claim as the seventh part of my Invention the combination of apparatus
above described.
I will now describe the eighth part of my Invention, which consists in crytal-
lizing cane juice or other saccharine solutions to dryness when boiling in open
vessels subject to the pressure of the atmosphere. Heretofore in the manufac-
ture of sugar it has been usual to boil the cane juice and other saccharine solu-
tions till it arrives at the point called "proof," and then to draw off cool and
crystalize the same. Now, according to this part of my Invention, I cause the
process of evaporation to be continued after the liquid has been brought to
"proof," and till the same is crystallized to dryness, taking care, however, to keep
down the temperature, particularly for the further evaporation, beyond proof, so
as to prevent burning. In carrying out this part of iny Invention I employ
pans or vessels with perforated pipes, or apparatus suitable for admitting air to
be forced in through the mass of crystals as they become more and more dry;
by this means the crystallized sugar may be kept down to a temperature of
one hundred and sixty degrees to one hundred and ninety degrees of Fahrenheit,
which is the degree of heat I prefer. By this mode of treatment I greatly
increase the production of sugar, by avoiding the making molasses heretofore
consequent on ceasing evaporation when the liquid has been brought to
proof." The sugar thus made is to be dug out or discharged from the pan,

page_text: preferring previously to cool the pipes or surfaces by or through which the
steam is applied for heating the liquid by introducing cold water therein or
thereto. I would state that I am aware that the introduction of air into
saccharine fluids in the manufacture and refining of sugar is not new, it having
been practised for the purpose of bringing such fluids to proof at a low
temperature. I do not therefore claim the same, this part of my Invention
consisting of carrying on the process of evaporation after the liquid has been
brought to "proof," in order to obtain crystallized sugar therefrom in a state
of dryness, using suitable means for keeping down the temperature, thus
avoiding the ordinary process of crystalizing after the liquid has been brought
to proof.