IMPROVEMENTS IN THE PROCESS OF REFINING AND MANUFACTURING SUGAR
Year: 1853

page_text: LETTERS PATENT to Henry Bessemer, of Baxter House, Old St.
Pancras Road, in the County of Middlesex, Engineer, for the
Invention of "IMPROVEMENTS IN THE PROCESS OF REFINING AND
MANUFACTURING SUGAR."
Sealed the 22nd September 1858, and dated the 15th July 1853.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer
at the Office of the Commissioners of Patents, with his Petition,
on the 15th July 1853.
I, HENRY BESSEMER, of Baxter House, Old Saint Pancras Road,
in the County of Middlesex, Engineer, do hereby declare that the
nature of my Invention of "IMPROVEMENTS IN THE MANUFACTURE AND
REFINING OF SUGAR" to be as follows:-
In the process of refining sugar, as at present generally practiced,
the syrups are put into conical iron moulds of so small a size as to
allow of their being easily lifted from place to place by the workmen
after they have been filled with syrup; this lifting of the moulds takes
place several times in the course of manufacturing each loaf of sugar;
and hence with the present process the size of the moulds are limited
to that which the workmen can handle with facility; in order to displace

page_text: the loaf of sugar from the mould a smart blow is given to the open
end of it, either by inverting the mould and striking it forcibly against
the floor, or it may otherwise be affected by bringing a heavy body
forcibly against the mould while held by the workman in a horizontal
position; in order that the loaf may be detached by these means it is
necessary to give the mould a very conical form, otherwise the difficulty
of removing it by such means would be very great, if not 'wholly
impracticable; near the bottom of the ordinary sugar mould the cone is
formed at a much more obtuse angle than the body of the mould, and
in the centre of this lower cone is a small opening, varying from to
an inch in diameter, through which the mother liquor and other
syrups slowly exude. The practice of limiting the size of the sugar
mould as before mentioned, and the conical form given to it, cause the
following disadvantages in the manufacture which the present Inven
tion is intended to lessen or entirely remove.
The large upper end of the loaf is always imperfectly formed, owing
in a great measure to the cooling influence of the atmosphere, and this
surface of inferior sugar is greatly increased by the conical form of the
mould, while the mother liquor and syrups are much retarded in their
escape from the mould by the diminished area through which they have
to percolate as they descend in the cone, and more especially as they
approach the small opening in the apex, where the area through which
the syrup has to force its way is not equal to a hundredth part of the
superficial area from which the syrups are drained, and thus the time
occupied in the drainage and liquoring" of the loaf is greatly increased
as compared with the time that would be occupied in the process if the
mould was cylindrical, and the escape area equal to the other part of the
mould; with regard to the height or length of the loaf as at present
manufactured, whatever be the height of the loaf the bottom of it will
always contain a certain quantity of syrup which is there suspended by
capillary attraction; the presence of this syrup lessens the value of the
lower part of the loaf; it is therefore cut off, and a new point given to
the loaf in a cutting machine. I have before mentioned that the upper
end of the loaf is also defective; if we take two feet to be the average
length of a sugar loaf there will be two defective portions in cach two

page_text: feet length; and it will be obvious that if the loaf were made from 8 to
16 feet in length instead of two feet, that a considerable diminution
would be made in the quantity of inferior sugar, and a corresponding
increase of the superior kind. Having thus pointed out the more pro-
minent disadvantages resulting from the present size and construction
of of sugar moulds, I will proceed to describe the inethods by which the
same may be lessened or wholly avoided.
I construct cylindrical sugarloaf moulds, having a movable bottoin,
so that the syrups may drain off from a surface, the area of which is
equal to the body of the mould; the mould may in consequence
be made of much greater height, because this increased area of outlet
will allow the syrups to drain off* quickly, which the hydrostatic
pressure of a tall column also assists; this increased capacity of the
moulds will render them too heavy to be handled by the workmen
in the usual way. I therefore prefer to make them fixtures, or movable
only on a revolving apparatus somewhat like a "turntable," and
instead of detaching the loaf from the mould by a blow, as usual,
I employ an hydraulic press or other suitable mechanical force to pushi
out the loaf from the mould; this may also be assisted by making an
opening on one side extending from the top to the bottom of the
mould, which is to be kept closed by suitable cramps, except during
the time that thé loaf is being displaced, when these cramps being:
unfastencil the mould may be expanded by screws, so as to facilitate
the removal of tlic large cylindrical mass
sugar. Any convenient
number of these large moulds may be secured in a vertical position to
a "turntable" by suitable stays; at the time of filling them they are
to be brought successively under a spout leading from the heater, and
by the saine micans they may in succession be brought over the ram of
a hydraulic press, which is to have a sufficiently long range to lift the
cylindrical mass into the floor above; immediately on removing the
bottom from the mould the lower end of the mould should be dipped
into a vessel containing syrup, otherwise the air might enter the pores
of the sugar, and render the drainage of the syrups unequal; the trim-
ming of the top end of the loaf and the liquoring" may be carried
on as usual; the turntable is also to be provided with suitable pipes for

page_text: conveying away the syrup from the moulds during the drainage and
liquoring of them. When the loaves or masses of sugar are lifted up
into the floor above by the hydraulic apparatus they are to be placed
long oven or
on carriages running on "rails" which pass into a
heating chamber, through which the rails are laid; this chamber may
either be heated by steam or water pipes placed along the floor of it, or
it may have a current of hot air passed along it by a "fan" or other.
suitable means, the air moving in an opposite direction to the sugar;
the oven should be of such length as to contain as much sugar as is
made in the establishment during the period necessary for its drying,
so that
every time a fresh carriage full of sugar is pushed into the end
of it a carriage laden with well dried sugar will be forced through a
door at the opposite end of the oven; when this mode of "stoving" or
drying sugar is intended to be applied to the smaller kind of loaves
several stages may be made in each carriage, which may be well filled
with loaves ranged on bars one above another, so that the workmen
will not have to enter the stove, as at present, to place and displace
the loaves.
I have before stated that a certain quantity of syrup is usually
retained in the lower part of the loaf or mass of sugar, which is sus-
pended there by capilliary attraction; the presence of this syrup lessens
the value of the sugar. I therefore prevent this retention of the syrup
by putting into the lower part of the mould any suitable porous or
granulated substances, which should occupy about 5 or 6 inches in
height, and be covered with a diaphragm of wire gauze or perforated
metal attached to a metalic ring, and secured thereby to the interior,
of the mould; a small piece of perforated metal is also to be fixed to
interior over the central apperture, so as to prevent the porous or granu-
lated substances from falling out, or otherwise these substances may
be contained in a bag made of any pervious textile fabric; when the
plug is inserted in the bottom of the mould as much uncrystalizable
syrup is to be put in as will fill the interstices of the granulated or
porous materials, after which the mould may be filled with concentrated
syrup; as soon as the syrup is crystalized the plug may be withdrawn,
when the drainage of the loaf will take place rapidly, because the

page_text: passage for the fluid between the granulated or porous substances will
be more open than through the net work of crystals usually forming the
point of the loaf, and hence a free drainage will take place from an area
equal to the size of the metalic diaphragm; the lowest part of the sugar
occupies a position an inch or two above the the point at which the fluid
can be suspended by capilliary attraction, and hence the lower part of
the loaf will be completely drained; the same efect may be produced
by putting into the lower part of the mould a large grained loose
sugar, mixed with uncrystalizable syrup, or by putting the bottom end
of a loaf back again into the mould; in either case the orifice at the
bottom end of the mould should be dipped into a small cup containing
syrup, so as to prevent the admission of air into the lower part of the
loaf; the cup may be suspended near the mouth of the "pot" in which
the moulds are placed to drain, so that it may overflow into the pot; by
this arrangement the time occupied in draining and liquoring the loaf
will be diminished, while the weight of loaf sugar will be increased;
where it is thought desirable to retain the pointed form of the apex, a
funneled shaped piece of wire gauze or perforated metal may be
fastened in the lower part of the mould at about 5 or 6 inches from
the bottom, so that when the loaf is "knocked out" the sugar
below it will be retained, and will thus form the wet point for each
succeeding loaf, while the loaf so formed will have a pointed end of
well drained sugar; in some cases the lower part of the mould, with its
wire gauze or perforated diaphragm, may be made movable, so as to be
taken off from the mould when required.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Bessemer in the Great Seal Patent Office,
on the 14th January 185.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
HENRY BESSEMER, of Baxter House, Old Saint Pancras Road, in the
County of Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of July, in the year of

page_text: year
our Lord One thousand eight hundred and fifty-three, in the seventeenth
of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Henry Bessemer, Her special licence that
T, the said Henry Bessemer, my executors; administrators, and assigns,
or such others as I, the said Henry Bessemer, my executors, adminis-
trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and-Isle of Man, an Invention for "IMPROVEMENTS IN
THE PROCESS OF REFINING AND MANUFACTURING SUGAR," upon the condition
(amongst others) that I; the said Henry Bessemer, by an instrument in
writing under my hand and seal, should particularly describe and ascer-
tain the nature of the said Invention, and in what männer the same was
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent..
NOW KNOW YE, that I, the said Henry Bessemer, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof (that is to say):
"
"
These improvements consist, firstly, in separating the whole "or
greater part of the glucose matter or uncrystalizable colored syrups
from sugar prior to the manufacture of such sugar into loaves, lumps,
or concrete masses, instead of separating such glucose matters after the
loaf or lump of sugar has been formed, as heretofore practised in
refining sugar, and hence, the process of liquoring or claying" the
loaf may be wholly or in part dispensed with. In carrying into opera-
tion this part of my Invention the raw sugar may be dissolved in
water, "blown up," and passed through aninial charcoal in the usual
way; the saccharine fluid is then to be concentrated to a density of
about forty-five degrees Beaumé; this process of concentration I prefer
to accomplish by bringing the fluid in contact with currents of warm dry
air, at a low temperature, in an improved apparatus, for which I ob-
tained a Patent lated the Nineteenth day of November, One thousand

page_text: eight hundred and fifty-two; nevertheless, in carrying into effect my
present Invention the vacuum pan may be used in lieu thereof. By
whatever means the process of evaporation is effected, the syrup, when
sufficiently dense, is to be heated in the usual manner to a temperature
of about 170 to 180 degrees Fahrenheit, and then put into large crys-
talizing vessels; which may be made of wood, and preferably of a
circular form, capable of holding about one ton each, or it may be put
into common sugar moulds; in either case the process of draining,
claying, and liquoring is not to be effected in these vessels or moulds,
but as soon as the sugar has completely crystalized, the whole matters
are to be removed from the vessels in a "green state," and are then
sliced or broken up so as to render the sugar suitable for the process of
washing or cleansing in a machine, whereby the uncrystalized colored
syrup may be separated from the crystals of sugar. The apparatus
best suited to perform this washing or cleanising process is described in
a Patent granted to me on the Nineteenth day of November, One
thousand eight hundred and fifty-two, numbered ; nevertheless,
the washing or cleansing of the sugar for the purposes of this Inven-
tion may be effected by other machines, such as the centrifugal
curing machine. The crystals of sugar so treated and cleansed from
their usual admixture of glucose or uncrystalizable colored syrup are
in a condition suitable for the formation of a loaf or concrete mass
of sugar according to this Invention; the crystals obtained by any
combination of the before-named processes I distinguish by the term
of product No I., and the fluid inatter separated therefrom I call
product No 2, and so on, using other numbers to distinguish the
different products as a means of identifying the particular quality of
sugar or surup referred to. In order to form a loaf of sugar with
the product No I. I take as much hot water or syrup, No 8, (resulting
from a previous operation) as will, when sprinkled on the sugar, in part
dissolve it; and form a semi-fluid matter, having a density of about
46 degrees Beaumé; the product No I., with its mixture of water or
syrup, is to be put into a vessel, the bottom of which is composed of a
row of small copper pipes placed parallel with each other, and nearly
close together; through the interior of these pipes hot water or

page_text: steam is made to circulate in order that the wet crystals resting upon
them, may acquire such a degree of heat as will cause a portion of
them to dissolve, and in this partially dissolved state to flow through
the spaces between the pipes, and be received in a vessel or heater
provided with a jacket for containing hot water or steam, for the
purpose of preventing loss of heat from the dissolved sugar during its
accumulation in the heater; when the charge of sugar has all flowed
into the heater, if its temperature be less than 180 degrees Fahrenheit,
is quickly to be brought up to that heat, and then, without loss of time,
put into moulds of the size and form desired; the moulds should be
placed in pots," and when the process of crystalization is completed
the plugs are to be withdrawn from the bottom of the moulds, and
the white mother liquor allowed to run out, which fluid has been
herein-before referred to as product N° 8. The loaves may then be
"cleaned off" and dried in a stove; should, however, the color of
the loaves not be quite so good as the manufacturer desires, "water
clay or liquor" may be used in such quantity as may be found necessary
to produce the required color; the "drips" resulting from such claying
or liquoring process may be mixed with No 3, product, and be worked up
in the manner before described in reference to that product; or the drips
may be returned to the evaporating pan. In the washing or cleansing
process which follows the first crystalization the saccharinc fluid N° 2,
is obtained, which consists of colored glucose matter combined with
dissolved crystalizable sugar and water; this fluid should be concen-
trated to a density of about 45 degrees Beaumé, and then be put into
large vessels or moulds to crystalize, after which the mass may be
subjected to the action of the washing or cleansing machine, when a
crystalized sugar will be obtained, which I call product No 4, and a
syrup No 5; the crystals N° 4, may either be mixed with water or
with syrup No 3, in such proportions as to yield a semi-fluid having a
density equal to about 46 degrees Beaumé; this mixture on crystalizing
will also yield loaf sugar of a good quality; or, in lieu of this mode
of treating it, the product N° 4, may be mixed with the crystals
No I., in the proportion in which they are produced, and which
mixture is to be treated in every respect as before directed in refer-

page_text: ence to product N° I.; whenever the syrups No 3, or the drips acquire
too deep a color, they may be put into the evaporating pan, and thus
form part of a new charge, so that ultimately the whole (or nearly so)
of the crystalizable matter may be converted into loaf sugar, the syrup
No 5, which is of a low or inferior quality, should be concentrated to
about 46 or 47 degrees Beaumé, after which it is to be crystalized,
and is then to be subjected to a powerful pressure in the manner
described in a Patent granted to me for "Improvements in the Manu-
facture and Treatment of Bastard Sugar, and other low Saccharine
Products, such as are obtained from Molasses and Scums," and which
Patent bears even date herewith. There results from this pressing
operation a product No 7, which consists of small crystals of bastard
sugar in a nearly pure state, and may therefore be sent to market;
but I prefer that it should be dissolved in a fresh solution of raw
sugar that has passed through the animal charcoal filter, or it may be
returned to the evaporating pan, where it will add to the density of the
syrup, and form part of a future first product; the last or eighth pro-
duct is treacle, which is obtained by pressure, as before mentioned, in a
fit state for sale, being the only product, except loaf sugar, obtained by
fully carrying out this process of refining. In the refining of sugar as
at present generally practised several different qualitics are produced,
cach having a different commercial value; one of the objects of my
present Invention is to more nearly equalize the value of such pro-
ducts by increasing the value of the more inferior kinds; this I effect
in the following manner: the inferior sugar, such as "pieces and
bastards," after crystalization has taken place, are to be washed or
pressed by any suitable machines, but instead of sending such washed,
cured, or pressed sugars to market, I dissolve them in the raw sugar
liquor after it has passed through the animal charcoal filter, or in lieu
of this the sugar may be put into the vacuum pan or other concen-
trating apparatus, whereby the inferior crystals are blended with the
new portions of sugar, and form part of the loaf which would otherwise
have been made from the raw sugar alone; it will be readily understood
that the process of evaporation is not increased by the addition of this
sugar to the liquor, whether it be added thereto in the pan or be dis-

page_text: solved in the filtered liquor before supplying the pan with it, so that all
the inferior crystalized products may be returned to the evaporator, and
be converted into sugar of first quality; in some cases sugars that have
been cleansed by machinery may be added to or mixed with the con-
centrated syrups while in the crystalizing vessels, where they will form
a nucleus on which a further crystalization will take place, and will
thus form a portion of the superior quality of sugar without causing
much additional labour or expense. I desire it to be understood that
I do not claim separately the several processes herein described, they
individually being well known, nor do I confine myself to the precise
details of the operations as explained, so long as the peculiar character
of the modes of working above described be retained. But I claim the
combined processes herein described of refining sugar.
In witness whereof, I, the said Heury Bessemer, have hereunto
set my hand and seal, this Fourteenth day of January, in the
year of our Lord One thousand eight hundred and fifty-four.
Witness,
S. CARPMAEL.
HENRY BESSEMER. (L.S.)