IMPROVEMENTS IN CENTRIFUGAL APPARATUS FOR DRYING SUGAR OR OTHER GRANULAR MATTERS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, DUNCAN STEWART, of the London Road Iron Works, Glasgow, in the County
of Lanark, North Britain, Engineer do hereby declare the nature of my said
Invention for "IMPROVEMENTS IN CENTRIFUGAL APPARATUS FOR DRYING SUGAR
OR OTHER GRANULAR MATTERS" and in what manner the-same is to be performed,
to be particularly described and ascertained in and by the following statement:-
My said Invention has for its object to construct centrifugal apparatus for
drying sugar or other granular matters so as to operate continuously in a
satisfactory manner.
In one modification of my improved apparatus the turbine or rotating basket is
placed with its axis horizontal and is at one end formed with a neck which works
in a stuffing box in a feeding hopper. Within the turbine there is a hollow drum
fixed on a central shaft, and leaving an annular cylindrical space between it and
the inner surface of the turbine. On the part of the shaft which passes through
the neck of the turbine there are helical or screw blades which feed the sugar from
the hopper to one end of the turbine. There are also screw blades on the outside
of the drum and they move the sugar slowly from one end of the turbine to the
other whilst it is being subjected to the centrifugal action; and at the end furthest
from the hopper the dried or drained sugar is thrown out through openings in an
enlarged part of the turbine into a compartment of a casing within which the
turbine is enclosed the separated molasses or syrup being received in another
compartment. The inner drum is by preference driven at a slightly greater velocity
than the turbine so that its screw blades may act the more uniformly and regularly
in moving the sugar along.
One modification of my improved apparatus is shown in the accompanying
explanatory Drawings of which there are two Sheets. Figure 1, on Sheet, 1, is a
longitudinal vertical section and Figures 2 and 3 on Sheet, 2, are tranverse vertical
sections as at the lines, A-A, and B-B, respectively, in Figure, 1.
A single main casting, 4, serves as the bedframe of the machine and is also
formed with part of the feed hopper, 5, with bearing supports, 6, 7, 8, for the
central shaft, 9, and for the neck, 10, of the turbine, 11, with the lower part, 12, of
a compartment for receiving the molasses or liquid from the sugar or other matters
operated on, and with the lower part, 13, of a compartment for receiving the dried
or drained sugar or other matters. The hopper, 5, is fitted with a rotating pronged
shaft, 14, driven by incans of a spurwheel, 15, and pinion, 16, from the central

page_text: shaft, 9, for keeping the sugar in a loose state; and stationary prongs are fixed to
the sides of the hopper as indicated at 17 in Figure, 2, to project in between the
prongs of the shaft, 14. At the bottom of the hopper, 5, there is a door and
slide, 18, to facilitate the cleaning of it. The neck, 10, of the turbine, 11, just
enters and turns in a stuffing box, 19, at the lower part of the hopper 5; and the
sugar is moved from the hopper along the neck, 10, by screw blades, 20, on the
shaft, 9, these blades being formed on a tube fixed on the shaft. The turbine
neck, 10, passes through bearings, 21, on the support, 7, and at the inner side of
these bearings has fixed on it a pinion, 22, by means of which it is driven, whilst
beyond the pinion the neck joins the slightly conical end, 23, of the turbine, 11.
This turbine end 23, is made with a flange, 24, which projects well within the
opening of the molasses compartment formed by the lower part, 12, herein before
referred to and the cover, 25, and which prevents the molasses from being thrown
out at the opening. The cylindrical shell of the turbine 11, is made with
strengthening ribs, and is formed in the usual way with holes for the escape of the
molasses or liquid, there being at the inside of the perforated shell a layer of
strong large-meshed wire gauze and at the inside of this a layer of fine wire gauze.
An inner hollow drum 26, is fixed on the central shaft, 9, and is of a size to
leave suitable spaces between its end, 27, and the end 23, of the turbine, and
between its cylindrical part and that of the turbine, for the passage of the sugar
from the neck, 10, to and along the latter space. The drum, 20, has screw
blades, 28, formed round its outside, their outer edges being nearly in contact with
the inside of the wire-gauze lining of the turbine, 11; and as the drum, 26, rotates
at a slightly different velocity from that of the turbine the action of the screw
blades, 28, is to slowly move the sugar along the turbine from the entering or neck end
towards the other end. The shell, 26, of the drum is perforated to allow air to pass out
to displace the syrup or liquid in the sugar, such air having access to the interior of
the drum, through openings in a wheel frame, 29, by means of which one end of
the drum, 26, is fixed to its shaft, 9, and also through a wheel frame, 30, which is
fixed to an outer enlarged part, 31, of the turbine, 11. Steam may be blown into
the hollow drum, 26, alone or along with air; and if thought desirable the central
shaft, 9, may be made tubular for the steam to be introduced through it and
through perforations at the part within the drum, 26.
The enclosing casing consisting of the lower parts, 12, 13, of the compartments
with their covering parts 25, 32, is divided by a partition, 33, at the part where
the enlarged part, 31, of the turbine joins the main part, 11; and a flange, 34, is
formed at that end of the main part of the turbine to overlap or cover the opening
in the partition. The enlarged part, 31, is made with openings (which may be of
any other convenient form instead of that shown) and as the dried or drained sugar
reaches that part it acquires increased centrifugal force and is thrown through the
openings into the compartment, 13. The bottom of this compartment is inclined
down towards an outlet, 35, through which the sugar passes directly or through a
shoot into any convenient receptacle. The compartment, 12, into which the
molasses or liquid is thrown is also provided with an outlet, 36, to which a
discharge pipe may be connected.
The wheel frame, 30, to which the enlarged end, 31, of the turbine is fixed is
formed with an elongated boss, 37, which is loose on the central shaft, 9, whilst its
outside forms a bearing surface or journal to run in bearings, 38 upon the support, 8.
The central shaft, 9, is driven by means of a pinion, 39, fixed on its end. The two
pinions, 22, 39, are by preference of steel and driven by cogged spur wheels on a
first-motion shaft, indicated by dotted circles in Figure 2, by which arrangement is
secured accurately the proper relation between the speeds of the turbine, 11, and
of the drum, 26.
The turbine, 11, with its neck, 10, and wheel frame, 30, may be made of brass,
or other suitable metal; or the neck, 10, may be made of steel, or there may be a
steel sleeve on the part of it running in the bearings, 21, as also on the journal
boss, 37, of the wheel frame, 30.
.

page_text: The apparatus may be placed with its axis otherwise than horizontal as shown,
the feeding and discharging parts being of course modified to suit whatever
position is adopted.
Having thus particularly described the nature of iny said Invention and in what
manner the same is to be performed I proceed to ascertain the distinctive features
of novelty thereof by declaring that what I claim is :-
1. The combination of parts forming the entire machine substantially as
hereinbefore described.
2. The construction of a centrifugal turbine with a feeding neck which passing
through a bearing and having on it a driving pinion or pulley communicates with
a feeding hopper, substantially as hereinbefore described.
3. The combination of a centrifugal turbine with an inner drum and shaft and
with screw blades for feeding the sugar or other matters into the turbine and
moving it or them along the turbine substantially as hereinbefore described.
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