Improvements in Centrifugal Machines.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Centrifugal Machines.
I, THOMAS LAW PATTERSON, of 29, Finnart Street, Greenock, in the County of
Renfrew, North Britain, Chemical Technologist, do hereby declare the nature of
this invention to be as follows, that is to say:-
This invention comprises certain improvements in centrifugal machines for
use, in sugar factories and refineries, and in various processes in the chemical
arts, which make it possible to separate and classify the drainage into two or more
portions according to its purity. As for instance in the sugar industry, the impure
molasses or syrups can be separated from the comparatively pure washings or
steamings. When the latter are returned to the pan and boiled into the same
quality of masse cuite as that from which they were separated the highest yield
of sugar will be obtained at the expense of the next lowest quality.
The improvements, which are applicable to under-driven or over-driven centri-
fugals, consist in fitting two slightly conical covers of sheet metal around the
outside of the basket in such a manner that the bases of the two cones very nearly
meet between the centre and bottom of the basket, forming an annular opening
through which the drainage escaping from the perforated shell, is discharged.
At this opening the edges of the cones may be flanged outwards to a small extent.
or turned over a wire to form a kind of lip. The cones are flanged upwards and
inwards at the top and bottom of the basket in order to catch any drainage from
perforations in these parts, or spill from over charging. And they are fastened to
the basket by bolts or rivets at the top and bottom in such a manner that a small
annular opening all around is left to allow the drainage or spill to pass to the dis-
charge annulus.
Instead of separate cones, a sheet of metal may be rolled in such a manner that
when the two ends are brought together, riveted and fastened to the basket it
forms a double conical cover projecting from the side about two inches all round
at the widest part. To allow the drainage to escape when the cover is in one
piece it is perforated with holes all round the widest part at the angle correspond-
ing to the annular opening of the separate cones. The cover will then act in the
same way as the cones.
Besides the ordinary gutter at the bottom of the casing, a movable gutter of
sheet metal two or three inches wide and three inches deep at one side, gradually
increasing in depth circumferentially both ways to five or six inches deep at the
opposite side, is made to fit loosely inside the outer casing. The back of the gutter
rises three inches higher than the front, and a strip of stout copper wire cloth is
rivetted on in front with the lower edge dipping into the gutter, to prevent the
drainage discharged against it splashing back. A pipe connected with the bottom
of the gutter at the deepest part is bent outwards through a slot in the outer
casing, to carry the drainage caught in the gutter to one or more suitable recep-
tacles. And the slotted opening is covered by a sheet metal plate attached to the
pipe or gutter in such a manner that the opening is always closed whether the
gutter is up or down.

page_text: Instead of a movable gutter, a fixed gutter and movable guard or shield may be
used. In this case the fixed gutter, similar in construction to the movable one, is
bolted on the inside of the outer casing at a convenient height above the ordinary
gutter in the bottom. And a movable circular guard or shield of sheet metal
flanged slightly inwards at the top, is made to fit loosely inside the fixed gutter,
between it and the basket.
The gutter or guard, as the case may be, is suspended by chains from pulleys
turning on spindles bolted to the casing of the centrifugal. A small spur wheel
attached to, or in one piece with, each pulley is geared with a rack underneath
bolted to a metal ring passing round the inside of the casing. The ring rests on
brackets with pins to keep it in position. Another spur wheel keyed on a spindle
passing through the casing, and having a hand wheel at the outer end, gears with
a similar rack attached to the metal ring, which is supported at this point by
another bracket. When the hand wheel, which can be clamped in position, is
turned, motion is communicated to all the wheels and pulleys inside the casing
through the metal ring, and the gutter or guard is raised or lowered by the chains.
When there is insufficient room between the basket and outer casing in old
machines to allow for fixing the apparatus above specified, or when room must be
left for the oscillation of the basket the outer casing will require to be made larger
in diameter. But in many centrifugals at present in use, especially in those with
fixed spindles, there is sufficient room, as not more than one inch say of clearance
is necessary between the gutter or guard and the conical covers.
In operating with the movable gutter, the gutter is raised to the top of the casing
by the hand wheel and clamped, where it cannot be soiled with impure drainage,
and where it is higher than the annular opening or perforations in the cover of the
basket. The machine is now charged and started in the usual way, and the syrup
or molasses, supposing it to be masse cuite that is under treatment passing through
the perforations of the basket, is caught on the conical cover and discharged
through the annular opening or perforations against the outer casing, flowing
away by the bottom gutter in the ordinary manner. The sugar in the machine
may now be washed with saturated solution of pure sugar or clairce, water or
steam. When the impure syrup or molasses is discharged the movable gutter is
lowered into position by means of the hand wheel, and the washings which are
very pure compared with the syrup or molasses, are caught against the wirecloth
and conducted outside the casing by the movable gutter and pipe, from which it
may be conveyed by suitably arranged gutters to as many receptacles as it is
desired to divide the washings for after treatment.
In operating with the guard or shield, the manipulation is similar to that with
the movable gutter except in this, that the guard intercepts the drainage when
raised to its highest position from which it drops into the ordinary gutter at the
bottom of the casing. And allows the washings to pass over the top against
the wire cloth into the fixed gutter when the guard is lowered below the lip of the
latter. The guard can be made to lift above the fixed gutter and allow the wash-
ings to pass beneath it, but I prefer the first method.
Dated this Twenty-ninth day of September 1897.
EDMUND HUNT,
Applicant's Agent.

page_text: this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, that is to say:-
This invention comprises certain improvements in centrifugal machines for
use, in sugar factories and refineries, and in various processes in the chemical
arts, which make it possible to separate and classify the drainage into two or more
portions according to its purity. As for instance in the sugar industry, the impure
molasses or syrups can be separated from the comparatively pure washings or
steamings. When the latter are returned to the pan and. boiled into the same
quality of masse cuite as that from which they were separated the highest yield
of sugar will be obtained at the expense of the next lowest quality.
My improvements, which are applicable to under-driven or over-driven centri-
fugals, are shown on two accompanying sheets of explanatory drawings, Figure, 1,
being a plan, with the top of the outer casing and basket removed, Figure, 2, a
vertical section, and Figure, 4, on Sheet, 2, a partial vertical section but drawn to
a larger scale of one modification. Figure, 3, on Sheet, 1, is a partial vertical
section showing a slight modification of details, Figure 5, on Sheet, 2, being a
similar view showing these details drawn to a larger scale.
The improvements consist in fitting two slightly conical covers A, B, of sheet
metal, around the outside of the basket, C, in such a manner that the bases of the
two cones very nearly meet between the centre and bottom of the basket, C, form-
ing an annular opening, through which the drainage escaping from the perforated
basket shell, C, is discharged. At this opening the edges of the cones, A, B, may
be flared outwards to a small extent, or turned over a wire to form a kind of lip.
The upper cone, A, is flanged or curved inwards at the top of the basket, C, in
order to catch any drainage or spill from over charging and they are fastened to
the basket, C, by bolts or rivets (not shown) at the top and bottom a small annular
opening all around being left at the top to allow the drainage or spill to pass to
the discharge outlet between the cones or covers.
Instead of separate cones, A, B, a sheet of metal may be rolled in such a manner
that when the two ends are brought together, riveted and fastened to the basket, C,
it forms a double conical cover projecting from the side about two inches all
round at the widest part. To allow the drainage to escape when the cover is in
one piece it is perforated with holes all round the widest part at the angle corre-
sponding to the annular opening between the separate cones, A, B. The cover
will then act in the same way as the cones.
Besides the ordinary gutter, D, at the bottom of the casing, E, a movable
gutter, F, of sheet metal two or three inches wide and about three inches deep at
one side, gradually increasing in depth circumferentially both ways to five or six
inches at the opposite side, is made to fit loosely inside the outer casing, E. The
back or outer side, G, of the gutter, F, rises three inches higher than the front,
and a strip of stout copper wire cloth, H, is rivetted on in front with the lower
edge dipping into the gutter, F, to prevent the drainage discharged against it
splashing back. A pipe, J, connected with the bottom of the gutter, F, at the
deepest part is bent outwards through a slot, K, in the outer casing, E, to carry
the drainage caught in the gutter, F, to one or more suitable receptacles (not
shown) and when the gutter, F, is raised as hereinafter described the slotted open-
ing, K, is covered by a sheet metal plate, L, attached to the gutter, F, in such a
manner that the opening, K, is always closed whether the gutter, F, is up or
down.
Instead of a movable gutter, a fixed gutter and movable guard or shield may be
used, as shown in Figures, 3, and 5. In this case the fixed gutter, F, similar in
construction to the movable one, is bolted on the inside of the outer casing, E, at
a convenient height above the ordinary gutter, D, in the bottom. Or the fixed
gutter, F, may be fixed to the casing so as to be partly inside and partly outside.
The movable circular guard or shield, Q, of sheet metal, is flanged slightly in-
wards at the top, and is made to fit loosely inside of the fixed gutter, F, between it
and the basket cover, A, B. The movable gutter, F, (Figures, 2 and 4), or the

page_text: movable guard, Q, (Figures, 3 and 5) as the case may be, is suspended by chains R,
from pulleys, S, turning on spindles, T, bolted to the casing, E, of the centrifugal.
A small spur wheel, U, attached to, or in one piece with each pulley, S, is geared
with a rack, V, underneath bolted to a metal ring, W, passing round the inside of
the casing, E. The ring, W, rests on brackets, X, with pins to keep it in position.
A handwheel, Y, is fixed on the outer end of one of the spindles, T, which is fitted
to turn in bearings and when the handwheel which can be clamped in position, is
turned, motion is communicated to all the wheels, U, and pulleys, S, inside the
casing, E, through the metal ring, W, and the movable gutter, F, or guard, Q, is
raised or lowered by the chains, R. Instead of fixing the handwheel, Y, on one of
the spindles, T, another spurwheel may be. provided, which is keyed on a similar
spindle passing through the casing and having a handwheel at its outer end, this
spurwheel will gear with another similar rack attached to the metal ring, which
will be supported at this point by another bracket.
When there is insufficient room between the basket, C, and outer casing, E, in
old machines to allow for fixing the apparatus above specified, or when room must
be left for the oscillation of the basket, the outer casing will require to be made
larger in diameter. But in many centrifugals at present in use, especially in
those with fixed spindles, there is sufficient room, as not more than one inch say of
clearance is necessary between the gutter or guard and the conical covers.
In operating with the movable gutter, F, which is shown in its lowest position
in Figures, 2 and 4, the gutter is raised into the upper part of the casing by the
handwheel, Y, as herein before described. In this position the gutter, F, cannot
be soiled by impure drainage getting access to it as it is higher than the annular
opening or perforations between the cones, A, B, forming the cover of the
basket, C. The machine is now charged and started in the usual way, and the
syrup or molasses, supposing it to be masse cuite that is under treatment passing
through the perforations of the basket, C, is caught on the conical covers and dis-
charged through the annular opening or perforations, flowing away by the bottom
gutter, D, in the ordinary manner. The sugar in the machine may now be washed
with saturated solution of pure sugar or clairce, water or steam. When the
impure syrup or molasses is discharged the movable gutter, F, is lowered into the
position shown in Figures, 2 and 4, by means of the hand wheel, Y, and the wash-
ings which are very pure compared with the syrup or molasses, are caught against
the wire-cloth, H, and conducted outside the casing, E, by the movable gutter, F,
and pipe, J, from which it may be conveyed by suitably arranged gutters (not
shown) to as many receptacles as desired so as to divide the washings for after
treatment.
In operating with the movable guard or shield, Q, and fixed gutter, F, as shown
in Figures, 3, and 5, the manipulation is similar to that with the movable
gutter (F) except in this, that the guard intercepts the drainage when raised to
its highest position from which it drops into the ordinary gutter, D, at the bottom
of the casing, E; and allows the washings to pass over the top against the wire
cloth, H, into the fixed gutter, F, when the guard, Q, is lowered below the lip of
the latter. The guard, Q, can be made to lift above the fixed gutter and allow
the washings to pass beneath it, but I prefer the first method.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. In centrifugal machines providing the basket with a cover having its widest
part between the centre and bottom of the basket at which part the cover is made
with an annular opening or perforations in combination with a vertically adjust-
able gutter having a strip of wire cloth dipping into it and being suspended by
chains from pulleys connected to spurwheels which gear with racks on a ring
turnable by means of a handwheel on one of the spindles, substantially as and for
the purposes herein before described,

page_text: 2. In centrifugal machines providing the basket with a cover having its widest
part between the centre and bottom of the basket at which part the cover is made
with an annular opening or perforations, in combination with a fixed gutter having
a strip of wire.cloth dipping into it; and a vertically adjustable circular guard
or shield fitting loosely on the inside of the fixed gutter between it and the basket
cover, and being suspended by chains from pulleys connected to spurwheels gear-
ing with racks on a ring turnable by means of a handwheel on one of the spindles,
substantially as and for the purposes herein before described.
Dated this Twenty-second day of June 1898.