IMPROVEMENTS IN APPARATUS FOR PURIFYING OR REFINING SUGAR
Year: 1877

page_text: LETTERS PATENT to Hugh William Walker, Sugar Refiner, and Thomas Law
Patterson, Analytical Chemist, both of Greenock, in the County of Renfrew,
North Britain, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
PURIFYING OR REFINING SUGAR."
Sealed the 22nd January 1878, and dated the 31st July 1877.
PROVISIONAL SPECIFICATION left by the said Hugh William Walker
and Thomas Law Patterson at the Office of the Commissioners of Patents on
the 31st July 1877.
16
IMPROVE-
HUGH WILLIAM WALKER, Sugar Refiner, and THOMAS LAW PATTERSON, Analytical
Chemist, both of Greenock, in the County of Renfrew, North Britain.
MENTS IN APPARATUS FOR PURIFYING OR REFINING SUGAR."
This Invention relates to the purifying or refining of sugar by treating it with air
combined with steam or moisture when it is in the centrifugal machine, and
comprises improvements in the apparatus for preparing or mixing the sugar before
putting it into the centrifugal machine, and improvements in the centrifugal
machine.
In carrying out the Invention the sugar to be operated upon is first, if necessary,
reduced by crushing to a uniform condition, and is then mixed with syrup obtained
from syrup previously treated in the improved apparatus, or with low syrup or
molasses obtained from raw or more or less refined sugars, such as "gilly," "bastards,"
the coarse products of the refinery, or with "char water" or other sweet waters or
syrups obtained by concentrating such sweet waters, the mixture being made in
such proportions as to form a thick magma resembling "masse cuite."
The mixing is effected in a cast iron cylinder, about 18 inches in diameter, having
short tubes of about 6 inches diameter at the ends, and fitted with a central shaft
on which are fixed radial blades arranged helically. One end of the shaft is made
hollow, and is connected by packed glands with a valve and pipe through which
the syrup or liquid to be mixed with the sugar is supplied, whilst just inside the
cylinder curved or radial branch pipes are fixed on the shaft for distributing the

page_text: liquid amongst the sugar, which is regularly fed in at the same end of the cylinder.
As the shaft revolves the sugar and liquid are thoroughly mixed, and the magma
formed is discharged at the other end of the cylinder into a receiver situated near
the centrifugal machines. The mixing cylinder may be placed horizontally or it may
be inclined.
The improvements in the centrifugal machine are applicable to machines like any
kind in use as regards the parts not altered by the improvements, whether they be
under driven or over driven. In the case of an under-driven machine a sheet metal
cover is fitted to the top of the basket, and after a charge of sugar, magma is filled
in, is secured by snibs, the joint at the periphery being made tight with a rubber
ring. A bell-like or other suitably shaped mouth-piece is fixed in the centre of the
cover, and a nozzle fixed to a steam pipe is placed so as to direct a jet of steam by
the tube into the basket, such steam jet causing a quantity of air to enter the tube
with it. At a short distance under the cover a sheet metal disc is fixed to receive
any drops of water due to condensation, such drops being by the centrifugal action
thrown from the edge of the disc into an annular pocket formed by a conical or
curved sheet metal ring attached to the inside of the cover and having its inner edge
below the disc. The water thrown into the annular pocket escapes by boles to the
outside of the cover, and thus drops are prevented from reaching the sugar.
In the case of over-driven machines the steam and air are introduced underneath,
and whilst the cover is made as already described, excepting that it is fitted to slide
on the shaft of the machine when lifted in opening the basket, there is substituted
for the disc a sheet metal cone or conoidal shell which directs any condensation
drops thrown outwards by centrifugal action into the annular pocket in the cover.
The lower part of the shaft is made tubular, and its bottom end terminates in a
bell-like or other suitably shaped mouth-piece, into which the jet of steam is directed
whilst the mixed air and steam or moisture issue from holes in the shaft into the
space within the conoidal shell.
The steam may be rendered cool and highly charged with aqueous vapor by
injecting water under pressure into the steam pipe or nozzle through a nozzle made
with fine holes.
In conducting operations with the improved apparatus herein-before described,
the sugar magma being placed in the centrifugal machine in the usual way, the
machine is set in motion, and when the syrup is considered to be completely
discharged, or nearly so, the steam jet is turned on and the water injection also, if
thought desirable. The supply of steam is kept up until the syrup running from
the machine is colorless or as nearly so as is wished. If the sugar is desired to be
soft, water may be injected with the steam towards the end of the operation and
will make the sugar more easily removable. The machine is, finally, run a few
minutes after shutting off the steam before discharging the sugar,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Hugh William Walker and Thomas Law Patterson in the Great Seal
Patent Office on the 29th January 1878.
HUGH WILLIAM WALKER, Sugar Refiner, and THOMAS LAW PATTERSON, Analytical
"IMPROVE-
Chemist, both of Greenock, in the County of Renfrew, North Britain.
MENTS IN APPARATUS FOR PURIFYING OR REFINING SUGAR."
Our said Invention relates to the purifying or refining of sugar by treating it
with steam combined with air when it is in the centrifugal machine.
In carrying out our Invention, the sugar to be operated upon is first, if necessary,
reduced by crushing to a uniform condition, and it is then mixed with syrup
obtained from sugar previously treated in our improved apparatus, herein-
after described, or with low syrup or molasses obtained from raw, or more or
less refined sugars, such as "jelly or "bastards," or the coarse products of the
or other sweet
refinery, or with syrups obtained by concentrating "char water
water, the mixture being made in such proportions as to form a thick magma
resembling "masse cuite."
"
but
The magma of sugar and syrup may be made in any suitable apparatus;
without making claim to any particular mixing apparatus, we will describe a con-
struction which we believe to be suitable and advantageous. This mixing apparatus
comprises a cast-iron cylinder, about 18 inches in diameter, having short tubes of
about 6 inches diameter at the ends, and fitted with a central shaft on which are
fixed radial blades, arranged helically. One end of the shaft is made hollow, and is
connected by packed glands with a valve and pipe, through which the syrup or
liquid to be mixed with the sugar is supplied; whilst just inside the cylinder,
curved or radial branch pipes are fixed on the shaft for distributing the liquid
amongst the sugar, which is regularly fed in at the same end of the cylinder. As
the shaft revolves the sugar and liquid are thoroughly mixed, and the magma
formed is discharged at the other end of the cylinder into a receiver situated near
the centrifugal machines. The mixing cylinder may be placed horizontally or it
may be inclined.
Our improvements in connection with the centrifugal machine are applicable to
machines which are like any kind in use as regards the parts not altered by the
improvements, whether the machines be under driven or over driven, and suspended
or otherwise arranged.
And in order that the construction and application of our improved apparatus
may be properly understood, we hereunto append two Sheets of explanatory
Drawings, to be herein-after referred to in particularly describing what we believe
to be the best arrangements or modifications for carrying out our Invention. In
these Drawings, the same reference numerals are used to mark the same or like
parts wherever they are repeated.
Figures 1 and 2, on Sheet 1 of the accompanying Drawings, are a vertical section
and a half plan of an under-driven centrifugal machine as fitted with a modification
of our improved apparatus. The top edge of the basket 1 is constructed in the
usual manner, with a flat annular rim or plate 2 projecting inwards a short distance
from the sides of the basket. For the space within the rim 2, there is provided,
according to our Invention, a cover 3 of sheet metal, which rotates with the basket;
and after a charge of magma is put into the basket, this cover 3 (with parts herein-
after described attached to it) is placed in position, resting on the inner edge of the
annular rim 2, the joint being made sufficiently tight by a lining of rubber which
is fixed on the under side of the edge of the cover. Any convenient form of snib,
fastening, or holder may be used to secure the cover in its place, but we prefer to
employ small weighted holders 4, hinged loosely to the under side of the cover,
which holders when the basket is rotating are, by the centrifugal force, made to
turn outwards and upwards against the under side of the basket rim 2, and thereby

page_text: bind the cover firmly down to that rim. These holders 4 have the advantage of
requiring no manipulation, as when the basket is not rotating they hang downwards
clearly within the rim 2, and do not interfere with the placing or removal of the
cover 3. A mouth-piece 5, which may be of the form shown, or cylindrical, or of
any other suitable form, is fixed on the centre of the cover 3, and a nozzle 6, fixed
to a steam pipe, and, by preference, adjustable in position, is placed so as to direct
a jet of steam downwards into the mouth-piece 5 in a manner to cause a quantity
of air to enter along with the steam jet. At a very short distance under the cover 3
a sheet metal disc 7 is fixed to the cover, and causes the mixed steam and air to
diverge in a disc-like form and spread outwards under the cover. This disc 7 also
receives any drops due to condensation, and such drops are, by the centrifugal
action of the rotation, also carried outwards, being thrown from the edge of the
dise 7 into an annular pocket 8, formed by the attachment to the under side of the
edge of the cover 3 of an annular conical or curved sheet metal ring 9, having its
inner edge below the edge of the disc 7. The water thrown into the annular
pocket 8 escapes by openings to the outside of the cover 3 and over the rim 2 of
the basket, and is thus prevented from reaching the sugar in the basket. A con-
venient way of forming the openings is by inserting radial strips of metal between
the edge of the cover 3 and the ring 9, so as to leave small passages when attaching
the latter to the former by rivetting or otherwise. The mixture of steam and air
passes down round the edge of the disc 7, and between the ring 9 and the upper
edge of a conical shell 10, and so has access to the sugar, whilst some of it may
proceed down within the conical shell 10, and through a narrow annular opening
between the bottom of that shell 10 and the usual central cone 11. The conical
shell 10 serves to collect any drops due to condensation on the central cone 11, and
with the aid of the centrifugal force, to lead them up into the annular pocket 8.
This conical shell 10 is fixed to arms 12, radiating from a ring which rests on the
central cone 11; it is also, by preference, attached to the cover 3, to be lifted out
therewith when charging the machine, although, if preferred, it may be arranged
to be lifted out separately.
Figures 3 and 4 on Sheet 2 of the accompanying Drawings are vertical and
horizontal sections of a centrifugal machine of the over-driven class, and having the
basket 1 suspended. In carrying out our Invention, in this case, the steam and
air are introduced underneath; and whilst the cover 3 is made to some extent as in
the first modification, it is formed with a sleeve 13 fitted to slide on the shaft 14
when lifted for opening the basket, and it may be secured in its closed or open
positions by means of a key fixed in a slot in the shaft 14, as indicated by dotted
lines in Figure 3, or it may when closed be secured by centrifugal holders 4, as in
the first modification. Beneath the cover 3, there is, as before, the annular pocket
8 and the conical shell 10; the arms 12 carrying the latter being attached to the
sleeve 13. In the lower part of the spindle or shaft 14 there is formed a hollow 15,
which is by preference of the tapering form shown, although it may also be of
uniform diameter or other suitable shape; and at the bottom of the hollow there is
a mouth-piece 5, which may be of the shape shown, or of a cylindrical or other
suitable shape. A jet of steam is directed by a nozzle 6 into the mouth-piece 5, so
as to carry in air with it, and the mixed air and steam issue from holes 16 in the
spindle 14 into the space within the conical shell 10. This shell 10 catches drops
due to condensation, and aided by centrifugal force leads them up into the annular
pocket 8, whence they escape outwards, as in the first modification. The mixture of
steam and air has access to the sugar in the basket by passing principally over the
top of the conical shell 10, whilst some may pass between the bottom of the conical
shell 10 and a hollow cone 17, which covers openings in the bottom of the basket,
and can be lifted in the usual way for discharging the sugar through those openings.
The steam jet nozzle 6 is on a branch steam pipe 18, which can be adjusted by
means of a screw 19; its inlet end being entered through a stuffing box.upon a
main steam pipe 20.
In conducting operations with our improved apparatus, the sugar magma having

page_text: been placed in the centrifugal machine in the usual way, the machine is set in
motion; and when the syrup is considered to be completely discharged, or nearly
so, the steam jet is turned on. The supply of steam is kept up until the syrup
running from the machine is colourless or as nearly so as is wished. The steam is
then shut off, the machine is stopped, and the sugar, which is then in a purified but
soft state, is discharged. If it is wished to have the sugar in a hard condition, the
rotation of the machine must be continued after shutting off the steam for a suffi-
cient time, say five minutes, when the sugar will be found caked to the sides of
the basket.
Having thus particularly described our said Invention and the manner of
performing the same, we have to state that we do not restrict ourselves to the
precise details herein described or delineated, but that what we believe to be novel
and original and claim as the Invention secured to us by the herein-before in part
recited Letters Patent is,-
1. The arranging or combining together of the parts of apparatus for applying
steam and air in purifying or refining sugar when in centrifugal machines, substan-
tially in the improved manner herein-before described, with reference to Sheet 1 of
the accompanying Drawings.
2. The arranging or combining together of the parts of apparatus for applying
steam and air in purifying or refining sugar when in centrifugal machines, substan-
tially in the improved manner herein-before described, with reference to Sheet 2 of
the accompanying Drawings.
3. The fitting of a rotating cover to the basket of an under-driven centrifugal
machine, used for purifying or refining sugar, such cover having fixed to it an open
mouth-piece for the reception of a jet of steam and of air taken in by such jet,
substantially as and for the purposes herein-before described.
4. The employment for purifying or refining sugar of a centrifugal machine
having a spindle, which has an open mouth-piece at its bottom end for the reception
of a jet of steam and of air taken in by such jet, and also a passage or passages
for leading the mixed steam and air into the basket, substantially as and for the
purposes herein-before described.
5. The appliances or attachments herein-before described, for leading water due
to condensation from within the basket, and so as to be discharged from the top
thereof by centrifugal force, substantially as herein-before described.
6. The application of the centrifugal holders (4) for securing the cover upon the
basket when rotating, as herein-before described.
In witness whereof, we, the said Hugh William Walker and Thomas Law
Patterson, have hereunto set our hands and seals, this Twenty-eighth day
of January, in the year of our Lord One thousand eight hundred and
seventy-eight.
HUGH W. WALKER. (L.S.)
T. L. PATTERSON.
(L.S.)