IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR DRAINING, DRYING, AND CONCENTRATING SUBSTANCES, AND IN THE METHOD OF AND Apparatus for PrEPARING SUBSTANCES FOR SUCH TDRARNDER DA DETAILY.ADTY ADRETRARLY BAD WE PRODICTION OF SUGAR
Year: 1875

page_text: LETTERS PATENT to Alfred Fryer, of Wilmslow, in the County of
Chester, and James Bingham Alliott, of Radford, in the County of
Nottingham, for the Invention of "IMPROVEMENTS IN THE METHOD
OF AND APPARATUS FOR DRAINING, DRYING, AND CONCENTRATING SUBSTANCES,
AND IN THE METHOD OF AND Apparatus for PrEPARING SUBSTANCES FOR SUCH
TDRARNDER DA DETAILY.ADTY ADRETRARLY BAD WE PRODICTION OF SUGAR "
PROVISIONAL SPECIFICATION left by the said Alfred Fryer and
James Bingham Alliott at the Office of the Commissioners of
Patents, with their Petition, on the 17th June 1875.
We, ALFRED FRYER, of Wilmslow, in the County of Chester, and
JAMES BINGHAM ALLIOTT, of Radford, in the County of Nottingham, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE METHOD OF AND APPARATUS FOR DRAINING, DRYING, AND CONCENTRATING
SUBSTANCES, AND IN THE METHOD OF AND APPARATUS FOR PREPARING SUBSTANCES
FOR SUCH TREATMENT, PARTICULARLY APPLICABLE FOR THE PRODUCTION OF SUGAR,"
to be as follows:-
Our improvements relate firstly to centrifucal machines used for such

page_text: purposes, and consist in improved apparatus for dealing with such sub-
stances as are difficult to drain by the ordinary centrifugal machines,
because the layers first drained under the influence of centrifugal force
form an almost impervious coating upon the filtering surfaces, and so
prevent the escape of fluid, also in apparatus for facilitating the dis- 5
charge of drained or concentrated material from the machine, and in
improved methods of preparing sugar for and treating it in the
centrifugal machine with the object of producing sugars similar in
quality to those usually known as loaf sugars, and in methods of and
apparatus for keeping separate the different qualities of drainings 1
from such machine, and finally in methods of and apparatus for
separating liquids from solids, when the solids are removed by centri-
fugal force from the surfaces where they have been deposited.
For the purpose of dealing with such substances as from their state of
minute subdivision are difficult to drain, we place them in a "cylinder" 1
or rotating vessel the walls of which (unlike those in general use) are
not perforated. Into this "cylinder" the fluid or semi-fluid substance
is allowed to flow in a continuous stream. The interior of this cylinder
is divided by diaphragms arranged radially or nearly so into a number of
cells, which become filled with the substance to be concentrated or from 2
which the solid matter is to be separated. The cells compel the contents
of the "cylinder" almost immediately to acquire the rapid motion at
which the "cylinder" itself rotates, and thus centrifugal force is at
once imparted to the said contents. The action of this centrifugal force
is to increase the effect of the difference between the specific gravity of 2
the solid matter and that of the fluid in which it is held in suspension,
and so to cause very rapid subsidence or separation.
The supply of fluid or semi-fluid is maintained continuously at one
part (preferably at one extremity) of the cylinder, and so soon as the
latter has become filled there is a continuous discharge of the lighter or 8
more fluid portions at another part of the cylinder (by preference at its
other extremity). This action is continued until the cylinder is
sufficiently full of solid matter, when the machine is stopped, the more
liquid portions of the contents being allowed to drain off, and the more
solid portion removed into another receptacle. The removal of the solid 8
portion may be effected by simply detaching it from the walls of the
cylinder, the lower lip of which forming also the lower part of the cells
is made curved or inclined towards the axis, so as to retain a sufficient

page_text: quantity of fluid while the machine is in motion, but curved or inclined
at such an angle that the solid matter when thus detached may readily
escape. Suitable arrangements are made below to direct the solid
matter into a different receptacle from that into which the fluid
descending from the same apertures has been guided.
In this method of concentrating the quantity of work done depends in
part upon the amount of surface over which the fluid from which the
solid matter is to be subsided flows. In order to increase this surface
we make use of two or more cylinders placed concentrically one within
the other. The outer portion of the inner cylinder then forms the
interior wall of the cells of the outer cylinder. In some cases we prefer
to perforate the interior walls of the cells of the subsiding cylinders and
to cover them with a filtering material. In this case these walls must
be provided with lips above and below, so that fluids can only find their
way to the inner side of these walls (that is, the side next to the shaft
upon which the cylinder rotates) by passing through the filtering
material.
Suitable provisions are made for drawing off and discharging (whilst
the machine is in motion) the fluid which has thus passed through the
filtering walls.
Our improved apparatus for discharging substances from the centri-
fugal machine consists in forming the draining or subsiding rotating
vessel in two portions each resembling a saucer or shallow basin in form.
These two portions are held firmly together with their lips or rims in
contact (or with the lip of one entering slightly within the lip of the
other), while the operation of draining or subsiding is going on, but are
so arranged that they can be slightly separated, thus leaving an open
space between the two portions of the vessel. This separation may be
effected whilst the machine is in motion.
We make the walls of the saucer with such an inclination towards the
lips where the two portions of the rotating vessel are divided that when
these are slightly separated, and an opening thus left, the contents of
the rotating vessel (under the action of centrifugal force) slide outwards
along the walls, and are thrown through the space left between the lips
of the two portions of the rotating vessel.
It will be observed that when this machine is in operation its contents
have a tendency to force or wedge the two portions of the rotating vessel

page_text: asunder. In order to diminish this action we attach to cach portion of
the vessel an inner diaphragm reaching nearly to the lip already men-
tioned, but allowing a sufficient space for the passage of the contents of
the vessel between it and the diaphragm. The contents of the vessel
pressing upon these diaphragms exert a force contrary to that which is
trying to separate the two portions of the vessel, and thus the effect of
this separating force is diminished.
We provide suitable means of separating the liquid discharged through
the walls from the solid matter discharged between the lips of the two
portions of the rotating vessel when they are separated, either by 1
curving these lips backwards so that a space may be left into which the
solid may be discharged, but into which none of the liquid draining
through the walls or over the sides can be thrown, or by providing a
removable casing (which would by preference be an inner one), which
can be moved upwards or downwards. This removable casing will 1
receive the liquid, and then be removed to allow the solids to pass
further out, and fall into another receptacle.
In some cases we arrange two or more of these self-discharging
rotating vessels upon a single shaft in such a way that when the one is
discharging, and being filled, the other or others will be engaged in draining a
or subsiding its or their contents, and for certain substances these rotating
vessels are arranged to subside and drain at one and the same time.
61
Our improved apparatus for producing in the centrifugal machine
sugar similar to that known as "loaf sugar" consists of several parts.
The boiled sugar or masse cuite is received direct from the vacuum 2
pan into vessels or moulds, each provided with a loose false bottom, and
also with loose plates which divide the mass into layers, but which how-
ever may be so made as to allow the whole mass to be held slightly
together by the sugar uniting around their edges or some of them. In
these vessels or moulds the "masse cuite" is moulded into the form of a g
truncated cone having a cylindrical or nearly cylindrical hollow axis,
while at the same time it is subdivided by the plates into comparatively
thin portions or leaves. As soon as this vessel or mould is filled with
sugar a cover fitting close down upon its contents is placed upon it, and
the whole is allowed to stand until the sugar cools, and becomes hard. 3
The loose bottom of the mould and the sugar upon it, together with the
cover, are then drawn out of the mould, and are dropped into the

page_text: rotating vessel of a centrifugal machine, the rotating vessel being made
to fit them. Herein the whole mass is held tightly together, and fitted
closely into the rotating vessel by means of an attachment connected to
the same, which enables the cover to be forced towards the narrower
end of the cone, thus pressing the sugar before it, and forcing the false
bottom, sugar, and cover as tightly as necessary into the rotating
vessel.
The next operation would in some cases be to drive off the "
green:
syrup" by putting the rotating vessel into rapid motion, and then the
white syrup or "clairce" would be added, while the rotating vessel
was made to revolve at a comparatively slow speed.
In some cases the white syrup or "clairce" would be added in the
first instance, and would drive the green syrup before it, but in many
cases the white syrup must be added when the machine is revolving at
a comparatively slow speed, in order that it may not pass through the
mass of sugar too rapidly, but may penetrate into every portion thereof.
This "clairce" may either be introduced all at once into the interior of
the hollow cone of sugar, where there is plenty of room to receive it,
and where it will be retained when the machine is in motion by means
of the cover projecting inwards nearly to the centre, around which the
cylinder rotates, or it may be introduced gradually while the machine is
in motion. The white syrup or "clairce" is afterwards drained off by
putting the rotating vessel into rapid motion. Steam is then in some
cases introduced with the object of still further purifying and hardening
the sugar, and then the machine is stopped, the cover loosened, and the
whole mass of sugar, together with the loose bottom, lifted out. The
cover having been removed the loose plates already spoken of permit
the mass of sugar readily to be separated into a number of comparatively
thin leaves or plates, which may if desired be dried in a stove. This
drying may be effected very rapidly, as the pieces of sugar are thin.
In the process of making sugar similar to loaf sugar the first fluid
drained by the centrifugal machine from the "masse cuite" is of low
quality, and is named "green syrup." This is followed by a syrup of
better quality, and this in turn by one still better in quality. By the
arrangements hitherto in use these syrups become blended to a con.
siderable extent, as for example, when a portion of fine "clairce" strikes
the casing at its lower part and near to the syrup exit pipe it becomes
:
•

page_text: "
mixed with inferior syrup that has left the "
'masse cuite some time
previously, and that has struck the upper part of the casing at some
distance from the exit pipe, because the viscous nature of the syrup
causes it to move slowly along the inner surface of the casing on its way
to the exit pipe.
Our improvements in keeping separate the different qualities of
drainings consists in surrounding the rotating cylinder or vessel with
and attaching thereto a conical casing, on the inner surface of which the
syrup is caught after leaving the perforated rotating vessel, and which
casing by reason of its conical form and of its rapid rotation immediately
delivers the syrup from the edge of its larger end. Thus the syrup is
all discharged in one plane, and is thrown outwards by centrifugal force.
A series of superposed circular channels are placed in contact and in
such a manner that the syrup escaping from the conical casing flies into
one of them, and by elevating or depressing the series of channels the
syrup may be directed at will into any of them. Each channel is con-
nected by suitable piping to the pipes or gutters which conduct the
syrup into its appropriate tank. This method of keeping the drainings
separate is applicable to other substances than sugar.
In some instances for the purpose of separating the liquid and solid :
portions of fluid or semi-fluid substances we use an apparatus consisting
of an hollow rotating shaft, to which we attach radially a number of
rectangular leaves or frames, which are either hollow and perforated, or
made of openwork, in such a way as (when covered with a woven or
felted material) to leave an open way in the interior for liquid to reach
the hollow shaft. These leaves or frames we cover with woven or felted
material. The apparatus stands within a vessel into which the liquid or
semi-liquid to be treated is suffered to flow. During the time that the
filtering is proceeding the whole apparatus is at rest and the liquid finds
its way through the woven or felted material into the interior of the
leaves or frames, and thence passes into the hollow shaft, through
which it flows away.
So soon as the surfaces become so foul that the liquid no longer flows
freely we draw out the untreated liquid remaining in the vessel and then
set the rotating shaft in rapid motion, when the leaves and the woven
or felted material with which they are covered also revolve with it.
The solid matter which rests upon the surfaces has thus a centrifugal

page_text: force imparted to it, which causes it to fly off and leave the surfaces
again clear, when the separating operation, as above described, may be
again resumed.
In some cases we substitute radial hollow rods or prisms of openwork
for the rectangular frames, over which we draw bags of woven or felted
material. The outer ends of such bags are closed and the inner ends
are severally connected with the central shaft in such a manner as to
leave an open way for liquid from their interiors to reach the hollow
shaft. The mode of separating the solid from the liquid portion of the
substance under treatment and the collection of such separated portions
by the use of centrifugal force is then effected in a manner similar to
that described where rectangular leaves are employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred Fryer and James Bingham Alliott in the
Great Seal Patent Office on the 17th December 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ALFRED
FRYER, of Wilmslow, in the County of Chester, and James BINGHAM
ALLIOTT, of Radford, in the County of Nottingham, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her.
Letters Patent, bearing date the Seventeenth day of June, in the
year of our Lord One thousand eight hundred and seventy-five, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto us, the said Alfred Fryer and
James Bingham Alliott, Her special license that we, the said Alfred
Fryer and James Bingham Alliott, our executors, administrators, and
assigns, or such others as we, the said Alfred Fryer and James Bingham
Alliott, our 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 THE METHOD OF AND APPARATUS FOR DRAINING, DRYING, AND
CONCENTRATING SUBSTANCES, AND IN THE METHOD OF AND APPARATUS FOR PRE-
PARING SUBSTANCES FOR SUCH TREATMENT," upon the condition (amongst
others) that we, the said Alfred Fryer and James Bingham Alliott, our
"

page_text: executors or administrators, by an instrument in writing under our 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 causo
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 we, the said Alfred Fryer and James Bingham
Alliott, 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 and accompanying
Drawings (that is to say) :-
Our improvements relate firstly to centrifugal machines used for such
purposes, and consist in an improved apparatus for dealing with such
substances as are difficult to drain by the ordinary centrifugal machines,
because the layers first drained under the influence of centrifugal forco
form an almost impervious coating upon the filtering surfaces and so
prevent the escape of fluid, also in apparatus for facilitating the dis-
charge of drained or concentrated material from the machine, and in
improved methods of preparing sugar for and treating it in the centri-
fugal machine, with the object of producing sugar similar in quality to
those usually known as loaf sugars, and in methods of and apparatus for
keeping separate the different qualities of drainings from such machines,
and finally in methods of and apparatus for separating liquids from
solids, when the solids are removed by centrifugal force from the surface
where they have been deposited.
Such being the nature and object of our said Invention, we will now
proceed to describe more in detail the manner in which the same is to
be or may be performed or carried into practical effect, and in order
that the same may be clearly understood wo have hereunto annexed a
Sheet of Drawings illustrative thercof, and have marked the same with
figures and letters of reference corresponding with those in the following
explanation thereof:
--
For the purpose of dealing with such substances as from their state
of minute subdivison are difficult to drain, we place them in a cylinder
or rotating vessel of that class wherein the walls are not perforated;
into this "cylinder" the fluid or semi-fluid substance is allowed to flow
in a continuous stream. The interior of this cylinder is divided by
diaphragms arranged radially, or nearly so, into a number of cells which

page_text: are closed on the inner side, as afterwards described, and which become
filled with the substance to be concentrated, or from which the solid
matter is to be separated. The cells compel the contents of the cylinder
almost immediately to acquire the rapid motion at which the cylinder
itself rotates, and thus centrifugal force is at once imparted to the said
contents. The action of the centrifugal force is to increase the effect of
the difference between the specific gravity of the solid matter and that
of the fluid in which it is held in suspension, so as to cause very rapid
subsidence or separation.
The supply of fluid or semi-fluid is maintained continuously at one
part (preferably at one extremity) of the cylinder, and so soon as the
latter has become filled there is a continuous discharge of the lighter or
more fluid portions at another part of the cylinder (by preference at its
other extremity). This action is continued until the cells of the cylinder
are sufficiently full of solid matter, when the machine is stopped, the
more liquid portion of the contents being allowed to drain off, and the
more solid portion removed into another receptacle. The removal of
the solid portion may be effected by simply detaching it from the walls
of the cylinder, the lower lip of which forming also the lower part of
the cells is made curved or inclined towards the axis so as to retain a
sufficient quantity of fluid while the machine is in motion, but curved
or inclined at such an angle that the solid matter when thus detached
may readily escape. Suitable arrangements are made below to direct
the solid matter into a different receptacle from that into which the
fluid descending from the same apertures has been guided.
In this method of concentrating the quantity of work done depends in
part upon the amount of surface over which the fluid from which the
solid matter is to be subsided flows. In order to increase this surface
we make use of two or more cylinders placed concentrically one within the
other, the outer portions of the inner cylinder then forms the interior
wall of the cells of the outer cylinder. In some cases we prefer to
perforate the interior walls of the cells of the subsiding cylinders, and to
cover them with a filtering material. In this case the walls must be
provided with lips above and below, so that fluids can only find their
way to the inner side of these walls (that is the side next to the shaft
upon which the cylinder rotates) by passing through the filtering
material

page_text: Suitable provisions are made for drawing off and discharging (whilst
the machine is in motion) the fluid which has thus passed through the
filtering walls.
In the annexed Drawing Fig. 1 is a vertical section, and Fig. 2 is a
horizontal section taken across the line a, b, of a rotating centrifugal
apparatus, the walls of which are not perforated. The same letters
apply to both Figures. To a shaft o a boss d (preferably of cast iron) is
securely and centrically attached. Around this boss 3 concentric
cylinders e, f, g, are disposed; these cylinders are preferably made of
wrought iron or steel; these are held in position, and caused to rotate
with the boss by the connecting rods or bars h; they are also held in
position by vertical radial divisions, which will be subsequently
described. The outer cylinder e is curved over inwards at the top
at i, and inclined inwards at the bottom at j. A ring at k attached to
the cylinder divides it into a smaller upper portion and a large lower
onc, and marks the upper limit of the radial divisions to be afterwards
described. A small ring is placed in or near the position indicated,
and is secured by several arms (not shown in the Drawing). The
middle cylinder f is terminated at its upper and lower ends by the
conical pieces, as shown. The inner cylinder 9 is terminated at the
lower end only by a conical piece. The space between the outer and
middle cylinders as well as between the middle and inner cylinders is
occupied by a number of radial divisions m, which extend throughout
the whole height of the middle cylinder, and from j to k of the outer
cylinder.
The method of separating substances of different specific gravities by
means of a centrifugal machine with imperforate shell is very well
known, and has been adopted by us and by others for a long period. It
has been usual to furnish such machines with radial divisions extending
but a short distance inwards from the imperforate shell, and upon any
considerable change of velocity of the machine the substance acted
upon climbed over the radial divisions and became intermixed.
By our improved method the open pockets are abolished, and closed
cells are substituted. These cells remain quite filled during the greater
part of the time when the machine is in operation, and as each cell is
only open at or near its extremities there is no opportunity for the

page_text: contents to escape from cell to cell in consequence of change of
velocity.
The mode of operation is thus :-The machine in effect two machines
placed concentrically, and each of which may be used indepen-
dently of the other, we will describe them separately, the outer one
first.
We will suppose for convenience of description that the substance to
be operated on is the sludge which has been deposited at the bottom of
the sewage subsiding tanks. The machine having been put in rotation a
stream of the tank sludge is discharged into the space i, k, l, at the
upper part of the cylinder e, and in the direction of the arrow. By
friction against the sides it acquires a circular motion, and when the
division is filled the sludge overflows the inner edge of the ring & into
cells m, m, into which the lower part of the cylinder is divided.
When these cells become filled the liquid portions are ejected beneath
the lower edge at j, and the solid portions are packed by the centrifugal
force against e. This process is continued until the cells become filled
or nearly so with solid 'matter, when the machine is brought to rest.
The small portion of the fluid which is left leaves the machine by gravity,
and is conveyed into a suitable receptacle. The more solid portions
are then removed by being forced downwards through each cell.
We will now describe the mode of working the middle cylinder f.
The stream of sludge is introduced in the direction of the dotted
arrow; it strikes the central boss, and is thrown by centrifugal force
against the inner face of the inner cylinder g. Being unable to escape
at its lower extremity by reason of its conical bottom it flows upwards
and passing over the upper edge finds its way into the cells m, m;.which
occupy the whole space between ƒ and g. In its upward journey it
acquires the rapid circular motion of the cylinder, and is thus free to
enter the cells m; it also leaves behind it some of the grosser portions.
of the solid matter, which form a coating on the inner side of the.
cylinder g. The flow of sludge is continued until the cells are filled or
nearly so with solid matter; clear liquid meanwhile having escaped
beneath the lower conical edge of the cylinder fat n. The mode of
'emptying resembles that already described.
Our improved apparatus for discharging substances from the centrifugal.
machine consists in forming the draining or subsiding rotating vessel in two

page_text: portions, each resembling a saucer or shallow basin in form; these two
portions are held firmly together with the lips or rims in contact (or
with the lip of one entering slightly within the lip of the other) while
the operation of draining or subsiding is going on, but are so arranged
that they can be slightly separated, thus leaving an open space between
the two portions of the vessel. This separation may be effected whilst
the machine is in motion.
We make the walls of the saucer with such an inclination towards the
lips where the two portions of the rotating vessels are divided that when
these are slightly separated and an opening thus left the contents of the 1
rotating vessel (under the action of the centrifugal force) slide outwards
along the walls, and will be thrown through the space left between the
lips of the two portions of the rotating vessel.
It will be observed that when the machine is in operation its contents
have a tendency to force or wedge the two portions of the rotating vessel 1
asunder. In order to diminish this action we attach to each portion of
the vessel an inner diaphragm reaching nearly to the lip already men-
tioned, but allowing a sufficient space for the passage of the contents of
the vessel between it and the diaphragm. The contents of the vessel
pressing upon these diaphragms exert a force contrary to that which is 2
trying to separate the two portions of the vessel, and thus tho effect of
this separating force is diminished.
We provide suitable means of separating the liquid discharged through
the walls from the solid matter discharged between the lips of the two
portions of the rotating vessel, when they are separated either by curving 2
these lips backwards, so that a space may be left into which the solid
may be discharged, but into which none of the liquid draining through
the walls or near the sides can be thrown, or by providing a removable
casing (which would by preference be an inner one) which can be moved
upwards or downwards; this removable casing will receive the liquid, 8
and then be removed to allow the solids to pass further out and fall into
another or outer receptacle.
In some cases we arrange two or more of these self-discharging
rotating vessels upon a single shaft in such a way that when the one is
discharging and being filled the other or others will be engaged in 3
draining or subsiding its or their contents, and for certain substances
these rotating vessels are arranged to subside and drain at one and the
same time.

page_text: Fig. 3 on the Drawing is a longitudinal section of our improved
apparatus for discharging substances from the centrifugal machine.
Upon a shaft A, A, two sleeves B, C, are so placed as to permit their
being drawn along the shaft, but they are compelled to rotate with it.
To these sleeves saucer-shaped rotating vessels D, D, and E, E, are
severally securely attached. The edges of these vessels are brought into
contact at F, F, (but in some cases the lip of one saucer overlaps that of
the other). The saucers are perforated to admit of the passage of the
liquid to be removed by centrifugal force. The lips of the saucers are
curved back at G, G, and H, H, so as to catch the liquid thrown through
the walls of the saucers, and to deliver it at a distance from the place of
discharge of the solid portions of the substance operated on, which are
thrown out at F, F, when the lips are separated. The inner disos I, I,
J, J, are severally securely attached to the ends of the sleeves B and C,
and to the discs I and J the saucers D and E are attached by means of
arms K. so placed as not to materially obstruct the passage of the sub-
stance to be operated on. The saucers are withdrawn apart and again
brought into contact by sliding one or both sleeves upon the shaft, and
this may be effected whilst the machine is in motion.
•
This apparatus may be modified by giving means of motion to one
sleeve alone, or one sleeve and its attachments may be worked against a
plain disc, cone, or saucer, instead of against its counterpart. One
sleeve may be provided with a saucer arrangement at each end, and
these may be alternately brought to bear against discs or saucers placed
so far apart as to permit the lips of one pair to be apart when those of
the other are closed.
6
"
Our improved apparatus for producing in the centrifugal machine
sugar similar to that known as "loaf sugar consists of several parts.
The boiled sugar or
mass cuite" is received direct from the vacuum
pan into vessels or moulds, each provided with a loose false bottom,
and also with loose plates which divide the mass into layers or leaves,
but which however may be so made as to allow the whole mass to be
held slightly together by the sugar uniting around their edges, or some
of them. In these vessels or moulds the "masse cuite" is moulded
into the form of a truncated cone, having a cylindrical or nearly cylin-
drical hollow axis, while at the same time it is subdivided by the plates
into comparatively thin portions or leaves. As soon as this vessel or
mould is filled with sugar a cover fitting close down upon its contents

page_text: '
is placed upon it, and the whole is allowed to stand until the sugar
cools and becomes hard. The loose bottom of the mould and the sugar
upon it, together with the cover, are then drawn out of the mould, and
are dropped into the rotating vessel of a centrifugal machine, the
rotating vessel being made to fit them. Herein the whole mass is held 5
tightly together, and fitted closely into the rotating vessel by means
of an attachment connected to the same, which enables the cover to bo
forced towards the narrower end of the cone, thus pressing the sugar
before it, and forcing the false bottom, sugar, and cover as tightly as
necessary into the rotating vessel.
The next operation would in some cases be to drain off the green
syrup by putting the rotating vessel into rapid motion, and then the
white syrup or
"clairce" would be added whilst the rotating vessel was
made to revolve at a comparatively slow speed.
1
In some cases the white syrup or "clairce" would be added in the 1
first instance, and would drive the green syrup before it; but in many
cases the white syrup must be added when the machine is revolving
at a comparatively slow speed in order that it may not pass through
the mass of sugar too rapidly, but may penetrate into every portion
thereof. This "clairce" may either be introduced all at once into the 2
interior of the hollow cone of sugar, where there is plenty of room to
receive it, and where it will be retained when tho machine is in motion
by means of the cover projecting inwards nearly to the centre around
which the cylinder rotates; or it may be introduced gradually while
the machine is in motion. The white syrup or
" clairce " is afterwards 2
drained off by putting the rotating vessel into rapid motion; steam is
then in some cases introduced with the object of still further purifying
and hardening the sugar, and then the machine is stopped, the cover
loosened, and the whole mass of sugar together with the loose bottom
lifted out. The cover having been removed the loose plates already 3
spoken of permit the mass of sugar readily to be separated into a
number of comparatively thin leaves or plates, which may if desired
be dried in a stove. The drying may be effected very rapidly as the
picces of sugar are thin.

page_text: of better quality, and this in turn by one still better in quality. By
the arrangement hitherto used these syrups become blended to a con-
siderable extent, as for example, when a portion of fine "clairce"
strikes the casing at its lower part and near to the syrup exit pipe,
5 it becomes mixed with inferior syrup that has left the "masse cuite"
some time previously, and that has struck the upper part of the casing
at some distance from the exit pipe, because the viscous nature of the
syrup causes it to move slowly along the inner surface of the casing
on its way to the exit pipe.
Our improvements in keeping separate the different qualities of
drainings.consist in surrounding the rotating cylinder or vessel with
and attaching thereto a conical casing, on the inner surface of which
the syrup is caught after leaving the perforated rotating vessel, and
which casing, by reason of its conical form, and of its rapid rotation,
immediately delivers the syrup from the edge of its larger end. Thus
the syrup is all discharged in one plane, and is thrown outwards by
centrifugal force. A series of superposed channels are placed in contact
and in such a manner that the syrup escaping from the conical casing
flies into one of them, and by elevating or depressing the series of
O channels the syrup may be directed at will into any of them. Each
channel is connected by suitable piping to the pipes or gutters which
conduct the syrup into its appropriate tank. This method of keeping
the drainings separate is applicable to other substances than sugar.
I
"
Fig. 4 in the Drawing is a vertical section of part of our improved
centrifugal machine for the draining of sugar similar to loaf sugar.
y, y, y, y, is the rotating vessel (slightly conical in form) secured to
the axial shaft Z. The method of supporting and actuating it, as well
as that of driving it at will at either of the two speeds is not shown. The
Drawing represents the machine charged with sugar X, X, which
reposes on the loose base W, W, and is protected on the top by the loose
cover V, V, which is held in its place by convenient means. This cover con-
tains a central hole for the admission of "clairce," steam, or other fluid.
The rotating vessel is perforated for the escape of the fluids. A conical
imperforate casing U surrounds the rotating vessel, and is attached to it,
and rotates with it. This casing serves to collect the fluids driven through
the perforations, and to deliver them in one plane. R, S, T, is a nest of
circular channels, which can be elevated or depressed at pleasure by any.

page_text: simple mechanical means in such manner that one or other of the channels
will receive the discharged liquid, and conduct it into its appropriate
receptacle. As shown in the Drawings the liquid will be thrown into
channel R, R.
"
In some cases we vary the method of attaining the same end by
making the side of the rotating vessel imperforate, except at the upper
part. We then leave spaces between the outer part of the sugar and
the side of the rotating vessel by interposing a piece of sievework or by
other convenient means, so as to furnish internal channels for the liquid
to traverse under the action of the centrifugal force. This liquid is dis- ]
charged through the apertures at the upper part of the rotating vessel,
and is delivered substantially in one plane. When this modification is
employed no outer rotating casing U, U, is used.
In some instances, for the purpose of separating the liquid and solid
portions of the fluid or semi-fluid substances, we use an apparatus con- 1
sisting of a hollow perforated rotating shaft, to which we attach radially a
number of rectangular leaves or frames, which are either hollow and
perforated or made of open work in such a way as (when covered with a
woven or felted material) to leave an open way in the interior for liquid
to reach the hollow perforated shaft. These leaves or frames we cover 2
with woven or felted material. The apparatus stands within a vessel,
into which the liquid or semi-fluid to be treated is suffered to flow.
During the time that the filtering is proceeding the whole apparatus is
at rest, and the liquid finds its way through the woven or felted material
into the interior of the leaves or frames, and thence passes into the 2
hollow shaft through which it flows away.
So soon as the surfaces become so foul that the liquid no longer flows
freely we draw out the untreated liquid remaining in the vessel, and
then set the rotating shaft in rapid motion when the leaves and the
woven or felted material with which they are covered also revolve with 8
it. The solid matter, which rests upon their surfaces, has thus a centri-
fugal force imparted to it, which causes it to fly off and leave the surfaces
again clear, when the separating operation, as above described, may be
again resumed.

page_text: material. The outer ends of such bags are closed, and the inner ends
are severally connected with the central shaft in such a manner as to
leave an open way for liquid from their interiors to reach the hollow
shaft. The mode of separating the solid from the liquid portion of the
5 substance under treatment, and the collection of such separated portions
by the use of centrifugal force is then effected in a manner similar to
that described where rectangular leaves are employed.
Fig. 5 is a horizontal section of the rotating portion of the draining
and concentrating apparatus for the purpose of separating the liquid
O and solid portions of fluid or semi-fluid substances. Q is the hollow
rotating shaft, preferably of metal; P, P, are rectangular frames of open
work, the inner parts of which are connected with the hollow shaft by
the perforations shown. Over the rectangular frames filtering material
of felted or textile fabric (shown by the dotted lines) is laid, and this is
3 held securely by the wedge-shaped blocks o, o.
Having now described the nature and object of our Invention,
together with the manner in which the same is to be or may be carried
into practical effect, we wish it to be understood that we claim as our
Invention,―
0 First. The "centrifugal subsider" or arrangement of apparatus, sub-
stantially as described with reference to Figs. 1 and 2, for effecting the
draining or concentration of substances by means of subsidence under
the action of centrifugal force.
Secondly. The arrangement of cells, substantially as described, in the
6 centrifugal subsider for the purpose of preventing the intermixture of
materials and the currents which occur when radial diaphragms only
are used.
Thirdly. The arrangement of the lower part of the centrifugal subsider,
substantially as described, permitting the apparatus to retain fluid
O within it whilst in rapid motion, and yet allowing the fluid to escape
freely when the machine is at rest, and also facilitating the discharge of
the solid matter from the machine.
Fourthly. The placing of one centrifugal subsiding cylinder concen-
11
L
L
tribunal anheiding orlinder of larger diameter

page_text: Fourteenthly. The substitution of radial hollow rods, cones, or prisms
of open work for the rectangular frames, as described in claim 18.´
In witness whereof, we, the said Alfred Fryer and James Bingham
Alliott, have hereunto set our hands and seals, this Fifteenth
day of December, in the year of our Lord 1875.
ALFRED FRYER.
(L.B.)
Witnessed by.
GEORGE DAVIES, C.E.,
Patent Agent,
Manchester.
JAMES, BINGHAM ALLIOTT. (L.S.)