IMPROVE. MENTS IN WASHING OR PURIFYING. AND TREATING SUGAR
Year: 1859

page_text: LETTERS PATENT to William Green, of Victoria Works, Dod Street,
Limehouse, in the County of Middlesex, for the Invention of "IMPROVE.
MENTS IN WASHING OR PURIFYING. AND TREATING SUGAR,"
Sealed the 22nd November 1859, and dated the 30th May 1859.
PROVISIONAL SPECIFICATION left by the said William Green at the
Office of the Commissioners of Patents, with his Petition, on the
30th May 1859.
I, WILLIAM GREEN, of Victoria Works, Dod Street, Limehouse, in the
County of Middlesex, do hereby declare the nature of the Invention for
"IMPROVEMENTS IN WASHING OR PURIFYING AND TREATING SUGAR," to be
as follows:
It is known that the color upon sugar is due to the presence thereon of a
thin coating of dark molasses. Various expedients have been employed for
removing this coloring matter, but owing to the loss resulting from the
operation, and the dryness and grayness of the crystals after being so treated.
they are but little employed. Now one object of the present Invention is to
remove or to overcome these objections, and to put on to the sugar as much
purified molasses as was washed off in a dark or impure state.
purpose I first remove the coating of molasses by centrifugal force; then,
having decolored the same, as herein-after described; and allowed the crystals
to dry and harden, I recoat the washed crystals therewith by mechanical
For this

page_text: means. I would state, however, that I am aware that washed sugars are
sometimes liquored in a separate centrifugal machine (to that in which they
were washed) immediately after the colouring matter has been partially
expelled, and also after being pressed into moulds, but in both cases more
syrup is employed than is retained upon the crystals; and not only is a portion
of the sugar carried off by the liquor by such treatment (thereby rendering the
process expensive), but if liquored while in a damp state, the crystals are
incapable of taking up so much of the molasses as they parted with in the
washing operation, hence a loss of weight in the resulting product.
In order to render the centrifrugal machine more efficient, I place around
the framework thereof a series of rollers, with suitable "doctors" attached.
These rollers are so placed that any matters expelled from the basket of the
machine may be received thereon, and being removed by the "doctors," pass
into suitable vessels alongside, thus allowing of fluids of different kinds being
conveyed to seperate receptacles, and of keeping the machine constantly clean.
Or instead of rollers, an endless band may be employed in connection with
suitable "doctors" or scrapers. The sugar before being placed in the machine
is slightly saturated with water or other fluid which has been reduced as
nearly as possible to the freezing point, it being known that the lower the
temperature of fluids the slower is their action in dissolving sugar. Or instead
of water, ice in a finely divided state may be employed. When the moisture
and colouring matter has been partially expelled, I apply from a perforated jet
or tube a spray or shower of water or other fluid of reduced temperature, and
in some cases add a slight tinge of colour thereto. When sufficiently cleansed
and dried, the sugar is removed and placed in a machine somewhat resembling
a churn, through the centre of which runs a perforated or slotted tube, from
which the bleached molasses or syrup is caused to drip on to the sugar as it
is turned over by the vanes of the machine. By this means the crystals become
thoroughly coated, and are brought as nearly possible to their original weight
and moisture, but free from impurities or objectionable colour. Or instead of
placing the cleansed crystals in the machine just described, they may be forced
into dies or moulds of an ornamental regular or irregular shape, but by
preference the latter, the primary object being to produce exact or fac-simile
imitations of the small irregular pieces of loaf sugar, as commonly sold by
grocers. In order to facilitate the adhesion of the crystals when thus moulded,
a strong liquor is used, either for or after the final washing, and in some
cases a small quantity of gelatine or its equivalent is added to the water or
liquor. When sufficiently set, the moulded pieces are coated with a con-
centrated solution of white sugar, in order to give them a bright crystalline

page_text: appearance, and either before or after this latter operation they may be stoved
in a similar manner to loaf sugar.
When a greater degree of whiteness is required than can be obtained by
washing, or as a substitute for the washing operation.I cause the sugar, either.
while in a dry or a saturated state, to be distributed in a finely divided con-
dition by centrifugal force, or currents of air or otherwise in a chamber, in
contact with fumes of sulphur or other bleaching agent, and in some cases such
agents are employed and made to impinge upon the sugar while in the
centrifugal machine.
The bleaching or decolourizing of molasses or syrups is effected thus:-In
order to obtain the full efficiency of animal charcoal, it is necessary to multiply
its points of contact by a mechanical sub-division thereof, and to bring the
syrups as intimately into contact with the carbon as possible, the intensity of
the action of the charcoal varying with its porosity or state of mechanical
division. In general cross-grained charcoal is employed by refiners, filtration
through it being more practicable than with fine boneblack, as the latter,
unless constantly stirred, settles in a compact mass at the bottom of the vessel
and.prevents the passage of the syrup. Now, as for the decolourizing of
molasses, the full energy of the charcoal is necessary, I prefer for this
purpose the use of fine boneblack, and in order to facilitate the passage of the
fluid, I divide the filter into a series of narrow compartments, placing a thin
layer of boneblack upon each. Any suitable mechanical means may be
employed for gently moving the several layers, so as to keep up a constant
separation of the particles, but I have found a series of vanes upon an upright
shaft, as also stout webs of india-rubber, placed upon perforated plates, to
answer well, as by the rotation of the vanes or the distention of the webs the
positions of the particles of carbon thereon are disturbed. The passage of the
fluid may be further facilitated by pneumatic power. Or instead of the above,
arrangement, the basket of a centrifugal machine may be lined with several
layers of boneblack of different degrees of fineness, suitable arrangements being
employed for keeping the same in a proper position, when the fluid having
been poured therein, will be expelled by centrifugal force. In some cases,
also, the sugar may be placed in a basket, thus lined, while in a saturated state,
and steam forced thereon while the machine is in motion, the inner casing
being made by preference of a woven material, so as to act as a filter for
mechanically separating the impurities in the sugar or molasses. When the
decolourizing properties of the charcoal are spent, steam rising in temperature,
to about 700 degrees to 500 degrees, may be forced on to it while in the
basket of a centrifugal machine,and afterwards a weak solution of carbonate

page_text: of ammonia,for the purpose of increasing its power of removing any excess of
lime used in defecation. Bituminous schist may be treated in a like manner,
and employed with advantage in connection with animal charcoal, as may also
an artificial charcoal composed of fifty parts of bituminous coal with from eight
to twelve of clay, and two of tar.
For removing matters from the basket of centrifugal machines, I employ a
scoop, which is free to slide up and down a stout shaft, and which scoop
capable of elongation or divergence when lowered into the basket; hence
when lowered, it first comes gently into contact with the casing of sugar, and
gradually diverges on one side till itapproaches or nearly approaches the wire
gauze lining of the basket.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Green in the Great Seal Patent Office on the
30th November 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GREEN, of Victoria Works, Dod Street, Limehouse, in the County of Mid-
dlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of May, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Green, Her special licence that I, the said William
Green, my executors, administrators, and assigns, or such others as I, the
said William Green, my executors, administrators, 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
WASHING OR PURIFYING AND TREATING SUGAR," upon the condition (amongst
others) that I, the said William Green, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner 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.

page_text: NOW KNOW YE, that I, the said William Green, do herchy 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 :-
It is known that the color upon sugar is due to the presence thereon of a
thin coating of dark uncrystallizable matter termed molasses or treacle.
Various expedients have been devised for removing this coloring matter, but
owing to the dryness, grayness, and loss resulting from such operations, they
are but little used. The modes which have in practice been found to answer
best, are to displace the colored matter by a superior saccharine fluid termed
liquor," either by the force of gravity, or by centrifugal force. Owing to the
expense of such syrrups or "liquors" however, even these modes are com-
paratively but little employed, in the case of "bastards" being entirely
neglected, and in other low qualities of sugar made by refiners and known as
low pieces" only occasionally used.
(i
Before proceeding to describe my Invention, however, I would have it
understood, that when speaking of "molasses," I do not mean the syrrups
which are imported into this country under the term "West India molasses"
or "colonial molasses," most of which are rich in sugar, some containing from
fifty to sixty per cent. of crystallizable sugar; but 1 mean the dark un-
crystallizable natter which, during the process of manufacture drips from the
lowest kinds of sugar ordinarily made by refiners, and termed by them
"bastards" and "low pieces."
I would also state, that I am aware that molasses have already been
employedinconnection with syrrups for "liquoring" sugarsandother purposes,
and also for imparting moisture to sugars previously. washed with water or
"liquor;" but by the present Invention, I propose to employ purified and
partially decolorized treacle without the addition ofsyrrups, for displacing from
sugar the dark inferior treacle, as well as for recoating the crystal so cleansed,
whereby the expense consequent upon the use of "liquors" or superior
syrrups will be avoided, and dryness will be prevented.
In carrying out this Invention, the sugar, if to be treated in the centrifugal
machine, which,as being the most expeditious mode of operation, is preferred,
is moistened with decolored treacle or other fluids of reduced temperature,
and in some cases with granulous ice. In applying the moisture, I prefer to
let it. pass over the sugar by the force of gravity, either in the mould, the
hogshead, or any other convenient vessel, or by exposure in thin layers to
steam, as any abrasion of the crystals by mechanical agitation tends to dissolve
the same, and so occasions loss. When sufficiently moistened, the sugar in

page_text: certain given quantities is put into the centrifugal machine, where the dark
uncrystallizable matter with which it was combined is expelled. A fresh
charge of decolored treacle (by preference, of reduced temperature,) is then
poured into the machine for the purpose of completing the cleansing, and
compensating for the loss occasioned by the operation. The mode of applying
this latter charge, however, will vary according to the nature of the sngar
under treatment. When a thin fluid has been employed for moistening the
sugar, it is well to let the crystals dry and harden before applying such
decolorized treacle, and then apply the same by means of a machine somewhat
resembling a churn, through the centre of which runs a perforated tube, from
which the decolorized treacle drips on to the sugar as it is turned over by the
vanes of the machine. This mode of coating crystals may also be employed
for sugars which have not been washed in the centrifugal machine. When
sugar's have a light drab or grey tinge, which is objectionable in the market,
it may be overcome by artificially coloring the crystals with a yellow color, as
saffron; or if the sugars are nearly white, by the use of a blue color. This
latter mode of improving the appearance of white sugar is already employed
by refiners for loaf sugar, I therefore lay no claim to it for that purpose, but
only for washed sugars.
Although I prefer the employment of centrifugal force for displacing the
dark uncrystalizable matter from "bastards" and other low quality sugar, I
do not confine myself to that mode, as the decolorized treacle may be employed
for displacing inferior treacle from sugar, either while in the mould, or by
pneumatic force, or otherwise. When the sugar has been removed from the
mould or other vessel in which its drainage took place, and it is desired to
improve its color by washing it with decolored treacle in moulds, the crystals
should be well divided, either by a pug mill or other mechanical agency, or by
exposure to steam previous to being placed in the mould. The decolored treacle
is then to be used as ordinary syrup or liquor. In some cases it is desirable
to convey the matters expelled from sugar by the centrifugal machine to
different recepticles, that throw off at one stage of the operation being
richer in sugar than that expelled at other stages thereof. In order to effect
this, I place around the framework of the centrifugal machine a series of
rollers with suitable "doctors" attached: These rollers are so placed, that
any matters expelled from or through the basket of the machine may be
received thereon, and being removed by the "doctors," pass into suitable
vessels alongside. Or, instead of rollers, an endless band may be employed in
connection with suitable doctors or scrapers.
When a good degree of whiteness has been obtained by the washing

page_text: operation, a substitute for loaf sugar may be made therefrom, by forcing the
same into dies or moulds of an ornamental, regular, or irregular shape, but,
by preference the latter, the primary object being to obtain exact imitations or
fac-similiesofthesmall irregularpiecesof loaf sugar, as commonly sold bygrocers.
In order to facilitate the adhesion of the crystals when thus moulded, a strong
liquor is to be used, either for or after the final washing, and in some cases
a small quantity of gelatine or other gummy or adhesive matter is added to
the water or liquor. When sufficiently set, the moulded pieces may be coated
with a concentrated solution of white sugar, in order to give them a bright
crystalline appearance, and either before or after the latter operation, they
may be "stoved" in a similar manner to loaf sugar. When ornamental or
irregular shaped blocks are to be formed, I sometimes employ "crushed
lump" or refined sugar direct from the "heater" instead of washed sugar.
When making irregualar shaped blocks, the sugar may be run, pressed, or
rolled into large cakes or slabs, and when sufficiently set,may be "liquored,"
so as to remove any color therefrom. Pneumatic force should be employed to
assist this latter operation. They are then to be "stoved," after which they
are to be cut into narrow strips by means of a press, or other mechanical
means, in which a series, or two series of parallel cutters are arranged at
about three-quarters of an inch apart. If the slabs were of a greater thickness
than about three-quarters of an inch, the strips are to be arranged in regular
rows, and again brought under the action of the cutters, after which their
positions are to be reversed, when by again bringing them under theaction of
the cutters they will be severed into small irregular blocks of the desired size.
When a greater degree of whiteness is required than can be obtained by
washing or as a substitute for the washing operation, I cause sugar, either
while in adry or a saturated state to be distributed in a finely divided condition
by centrifugal force or currents of air or otherwise in a chamber in contact with
fumes of sulphur, sulphurous acid gas, or other bleaching or decoloring agent,
and in some cases such bleaching or decoloring agents are applied to the sugar
or solutions of sugar while in the centrifugal machine. In speaking of the
use of bleaching or decolorizing agents in connection with the centrifugal
machine, I do not of course refer to "liquor" water or syrups, but to such as
are capable of acting chemically upon the coloring matters contained upon the
sugar while being mechanically forced over the same. Other mechanical
means may also be employed if desired in lieu of the centrifugal machine for
forcing the said bleaching agents over the crystals of sugar. I have found
sulphurous acid gas, either saturated with water or not, to answer well for the
above purpose upon some kinds of sugar, but various carbonaceous and other

page_text: fluids or gases may be employed with more or less success, I do not therefore
confine myself to any particular bleaching agents for this purpose, but employ
those which local or other reasons may render most advantageous.
The bleaching or decolorizing of molasses or syrups is effected thus:-In
order to obtain the full efficiency of animal charcoal, it is necessary to multiply
its points of contact by a mechanical subdivision thereof, and to bring the
syrups as intimately into contact with the carbon as possible, the intensity of its
action varying with its porosity or state of mechanical division. In general,
coarse-grained charcoal is employed by refiners for decolorizing syrups,
filtration through it being more practicable than with fine boneblack, although
the latter has sometimes been employed for assisting the removal of color
while defecating or clarifying syrups. The reason why fine boneblack is not
employed is that unless constantly stirred, it settles into a compact mass at
the bottom of the vessel, and prevents the passage of the syrup.
Now as the full energy of the carbon is necessary, especially when treating
treacle, I prefer for this purpose the use of fine boneblack or other car-
bonacious matters in a finely divided state, it being the carbon of the animal
charcoal which acts upon the coloring matter which it separates by union
therewith. In order to facilitate the action of the carbonacious matters upon
the treacle or syrups, the filter is so constructed as to keep the particles of
carbon in motion until their energy or decoloring property have been absorbed,
after which it is to be precipitated, and the decanted fluid filtered through
coarse charcoal. To effect this the charcoal inay be divided into a series of
narrow compartments or thin divisions alternated with thicker layers of coarse
charcoal, any suitable mechanical means being employed for gently moving
the several layers, and so keeping up a constant separation of the particles.
I have found a series of vanes upon an upright shaft, as also stout elastic webs
placed upon perforated plates.to answer well, as by the rotation of the vanes or
'the distension of the webs the positions of the particles of carbon thereon are
disturbed. Many different arrangements, however, may be employed for
keeping the fine carbonacious matter in motion with more or less success, aud
when the treacle is reduced sufficiently thin, the force of gravity will be
sufficient to produce the desired agitation. The downward motion of the
carbomacious matters through the syrup may be expedited by mixing therewith
small
quantity of aluminous or siliceous earth as coal measure, clay, or other
heavy or argillacious matter capable of uniting with the carbon,and increasing
its weight: When the fluid is made to pass over the charcoal, its passage may
be expedited by pneumatic power. Another arrangement for decolouring sugar
or treacle, and which is also applicable for dissolving and filtering sugar consists

page_text: in lining the basket of a centrifugal machine with a series of layers of bone-
black or other carbonaceous matters of different degrees of fineness, suitable
arrangements being employed for keeping the same in a proper position,
when the fluid having been poured therein will be expelled by centrifugal
force. When sugar is to be dissolved and filtered, it is to be placed in a
basket thus lined, while in a saturated state, and steam, by preference of low
pressure, or a spray of fluid forced thereon while the machine is in motion,
the inner casing being made by preference of a woven material so as to act as
a filter for mechanically separating the impurities in the sugar or molasses,
while they are at the same time partially decolored, and in the case of sugar
reduced to a liquid state. The inner lining of woven material will allow of
the machine being easily cleaned without loss of time, as such fabric when
clogged or dirtied may be readily removed and another substituted in its place
without disturbing the lining of animal charcoal. Although, however, I have
mentioned the use of a lining of animal charcoal when dissolving sugars by
the centrifugal machine, and also prefer the use of such, I do not say it is
indispensable,as the ordinary lining of the baskets of centrifugal machines will
answer the purpose very well. Indeed, the greatest defect in such machines,
when used for cleansing sugar, has been the facility with which they dissolve
the sugar under operation. This defect, therefore, I turn to an advantage,
and by its aid dissolve sugar at the greatest possible density, and the lowest
possible temperature. If so desired, the sugar under operation need not
be entirely dissolved, but small quantities of white crystals removed at
intervals.
When the decolorizing properties of the charcoal are spent, steam rising in
temperature to about 700 degrees to 800 degrees may be forced on to it,
while in the basket of a centrifugal machine, and afterwards a weak solution
of carbonate of ammonia for the purpose of removing any excess of lime used.
in defecation. Bituminous scbist may be treated in a like manner aud
also
employed with advantage in connection, with animal charcoal, as inay
an artificial charcoal composed of fifty parts of bituminous coal, with from eight
to twelve of clay and two of tar; these latter matters I. employ chiefly in a
finely divided or pulverized state in lieu of fine boneblack..
Although I have mentioned the revivifying of carbonaceous matters and
animal charcoal in a centrifugal machine, it is evident that the drum or basket
of such machine must be of a different construction to those ordinarily made,
as the heat of the steam would be more than they could withstand. The plan
which I prefer is to make such basket of cast-iron turned inside and out so as
1.4

page_text: to insure being equally balanced, the outer ring being drilled with small holes,
as close together as possible, compatibly with the strength required.
.
Although too I have spoken of the centrifugal machine for this purpose; I
have done so because it is necessary that the charcoal be clean before being
acted upon by the steam &c., and because I believe it to be the simplest and
cheapest mode of expelling foreign matters from charcoal; it is evident,
however, that many other arrangements may be employed for the purpose
with more or less success. One plan would be to force water over the
charcoal while in an ordinary filtering cylinder by hydraulic, pneumatic, or
other pressure, and after this the superheated steam and chemical agents; the
primary object of this part of my Invention being to cleanse and revivify the
said charcoal at one operation, and in the same vessel where it is used for
filtering syrups.
scoop
For removing matters from the basket of centrifugal machines, I employ a
which is free to slide up and down a stout shaft, and which scoop is
capable of elongation or divergence when lowered into the basket, hence wben
lowered it first comes gently into contact with the casing of sugar, &c., and
gradually diverges on one side till it approaches the wire gauze or perforated
copper lining or outer casing of the basket.
Having thus described the nature of my Invention, and the manner of
performing the came, I would have it understood that I claim,
First, the removing of color from the drippings from "bastards" or low
2. pieces" cominonly termed molasses or treacle, by means of animal charcoal
or other carbonaceous matters by preference in a finely divided state, or
arranged in thin layers of different degrees of fineness, and kept in motion by
the force of gravity or by mechanical means during the operation, as also.the
precipitation of the carbonaceous matters employed for such decoloration or
other matters in treacle, by means of aluminous, siliceous, or argilaceous
earths, then passing the treacle through a filter of granulous charcoal, the
said matters being kept cold or at a low temperature during the process."
Secondly, I claim the use of purified or decolorized treacle for displacing
dark or inferior treacle from bastards" or other low quality sugars, and at
the same time recoating such cleansed crystals..
Thirdly, I claim the use of fluids of reduced temperature for dissolving or
moistening the treacle or dark coloring matter contained upon "bastards" or
other low quality sugar, also the use of ice for such purpose.
Fourthly, I claim the manufacture of sipall blocks of sugar of regular;
irregular, or ornamental shape as described.

page_text: Fifthly, I claim the bleaching or decolorizing of sugar by means of fumes
of sulphur, sulphurous acid gas, or other bleaching or decolorizing agents in
the manner herein-before described.
Sixthly, I claim the bleaching or decolorizing of sugar by means of chemical
decolorizing agents in connection with centrifugal force.
Seventhly, I claim dissolving sugar to be manufactured into refined sugar
by means of fluids by preference at a low temperature, and of centrifugal
force, also the dissolving of sugar and filtering the syrups so obtained by
synchronous operations.
Eighthly, I claim the imparting of a yellow tinge to sugar by artificially
coating the same with saffrou or other suitable coloring matter, as also the
improving the appearance of crystals of sugar which have been washed nearly
to whiteness by imparting to them a blue tinge as commonly practised upon
refined sugar.
Ninthly, I claim the modes herein-before described of removing syrups and
sugar from centrifugal machines.
Tenthly, I claim revivitying animal charcoal, or similar matters by the
combined action of centrifugal force of chemical agents, and of high pressure,
orsuperheated steam; also cleansing and revivifying animal charcoal or similar
matters while in the ordinary filtering cylinder or vessel.
Lastly, I claim the coating of crystals of sugar, by mechanically agitating
the same while in contact with the syrups or other matters with which they
are to be coated.
In witness whereof, I, the said William Green, have hereunto set
my hand and seal, this Twenty-ninth day of November, in the
year of
our Lord One thousand eight hundred and fifty-nine.
W*. GREEN. (L.S.)