IMPROVEMENTS IN DRYING SUGAR, AND IN APPARATUS THEREFOR." PROVISIONAL SPECIFICATION
Year: 1881

page_text: LETTERS PATENT to Alexander Scott, junior, Joseph Duncan Scott, and
Thomas Robertson Ogilvie, all of Greenock, in the County of Renfrew, North
Britain, for an Invention of "IMPROVEMENTS IN DRYING SUGAR, AND IN
APPARATUS THEREFOR."
PROVISIONAL SPECIFICATION left by the said Alexander Scott, junior,
Joseph Duncan Scott, and Thomas Robertson Ogilvie at the Office of the
Commissioners of Patents on the 13th July 1881.
"
ALEXANDER SCOTT, junior, JOSEPH DUNCAN SCOTT, and THOMAS ROBERTSON
OGILVIE, all of Greenock, in the County of Renfrew, North Britain.
MENTS IN DRYING SUGAR, AND IN APPARATUS THEREFOR."
IMPROVE-
This Invention has for its object the drying of sugar in an improved and superior
manner, and by means of improved apparatus.
When sugar in the form of plates, sticks, pieces, crystals, grains, or powder is
dried in some existing arrangements of stoves and apparatus, it often assumes an
undesirable and unsatisfactory appearance, having become dimmed or dulled
through the action of the heated air when too much charged with moisture, or
when each portion of the air is allowed to act for too long a time on the same
portions or on successive portions of the sugar.
These defects or drawbacks are
by the present Invention avoided by causing the heated air to pass wear or in
contact with the sugar in a rapid manner, and in such suitably regulated current
or currents as that each portion will reach its outlet from the drying chamber
before it has become too much charged with moisture.
The improved apparatus consists, according to one modification, of a long chamber
made of wood, or metal, or other suitable material, or combination, and having at
its lower part a range, or series of steam-heated pipes or other convenient heated
surfaces. Partitions or covers may be arranged in connection with the heating
surfaces, so as to cause the air entering the chamber to pass close to such heating
surfaces. At the top of the chamber there is a flue or duct communicating with a
fan or air moving apparatus arranged to draw the air out of the chamber, and this

page_text: flue communicates with the interior of the chamber by a number of openings
which are fitted with slides or valves. The entrance of the air to the heating
apparatus and chamber is also controlled by means of a number of inlet openings
fitted with slides or valves. With these arrangements the air passes through the
chamber in a general vertical direction, and the rapidity of the currents at different
parts is regulated by adjusting the slides or valves, whilst the temperature is
regulated by suitably adjusting the supply of steam or other heating agent, which
may, if found desirable, be done so as to maintain a higher temperature at one end
or part of the chamber than at another.
If the sugar is in such a form as to be free from powder it may be placed on
perforated plates arranged as shelves in wheeled frames or carriages, or to be
placed as shelves on guide supports fixed in the chamber. The carriages are
preferred as affording facility in entering and removing the sugar, besides having
other advantages. The chamber may be arranged to contain a number of the
carriages in line, and the carriages may be put in and taken out singly or in sets at
such intervals as to allow each carriage to be in the chamber just as long as may
be requisite for the best treatment of the sugar carried by it.
Unperforated plates or trays may be employed instead of the perforated plates,
particularly when the sugar is in the condition of small crystals or powder; but
when dealing with sugar in that condition, travelling bands with lateral rims are
employed by preference, or plates arranged to move continuously or intermittently
-through the chamber. The sugar is supplied through a hopper, and as it is carried
along it is turned over and fresh surfaces exposed by rakes, or ploughs, or the like,
placed at intervals above the band or series of plates. Two or more bands or sets
of plates may be arranged one above the other or alongside of each other inside of
the same drying chamber. With these arrangements the sugar to be dried.
is continuously subjected to a continually changing atmosphere; and it rapidly
parts with its moisture without becoming conglomerated into lumps or cakes.
When the sugar reaches the end of the band or series of plates it falls down
a shoot into any convenient receptacle, and may, if thought desirable, be passed
between rollers to break down any slight agglomerations, but not so as to crush
the grains or crystals. The apparatus is well adapted for the preparation of
"granulated "sugar, in which case the sugar, after being dried, is sifted and filled
into packages.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Scott, junior, Joseph Duncan Scott, and Thomas
Robertson Ogilvie in the Great Seal Patent Office on the 12th January 1882.
ALEXANDER SCOTT, junior, JOSEPH DUNCAN SCOTT, and THOMAS ROBERTSON
OGILVIE, all of Greenock, in the County of Renfrew, North Britain. " IMPROVE-
MENTS IN DRYING SUGAR, AND IN APPARATUS THEREFOR."
Our said Invention has for its object the drying of sugar in an improved and
superior manner, and by means of improved apparatus.
When sugar in the form of plates, sticks, pieces, crystals, grains, or powder, is
dried in some existing arrangements of stoves and apparatus, it often assumes an
undesirable and unsatisfactory appearance, having become dimmed or dulled through
the action of the heated air when too much charged with moisture, or when each
portion of the air is allowed to act for too long a time on the same portions or on
successive portions of the sugar. These defects or drawbacks are by our present
Invention avoided by causing the heated air to pass near or in contact with the
sugar in a rapid manner, and in such suitably regulated current or currents as that
each portion will reach its outlet from the drying chamber before it has become too
much charged with moisture.
And in order that our said improved process for drying sugar, and our improved
apparatus or arrangements for practically carrying out the said process may be
properly understood, we hereunto append two Sheets of explanatory Drawings, to
be hereinafter referred to, and representing two modifications of our improved
apparatus.
Figure 1 on Sheet 1 of the accompanying Drawings is a longitudinal vertical
section of a long drying chamber, but with a considerable portion of the middle
part supposed to be removed; Figure 2 on Sheet 2 is an enlarged transverse
vertical section, and also shows in end elevation one of the carriages employed to
convey the sugar through the drying chamber in one modification; Figure 3 is a
side elevation of the carriage; Figures 4 and 5 are longitudinal and transverse
vertical sections of a second modification, in which endless bands are used instead
of carriages for conveying the sugar through the drying chamber. In these Drawings
the same reference numerals are used to mark the same or like parts wherever they
are repeated.
In Figures 1 and 2 of the Drawings the long drying chamber 6, 7, is repre-
sented as made of wood, but it may be constructed of metal or other suitable
material or combination of materials. It consists mainly of vertical sides 6, with a
roof 7 formed by boards fixed upon a suitable framework, and erected upon a floor $
of the sugar house. Doors 9, 10, are fitted at the ends of the chamber, and are
closed whilst the drying operation is proceeding. Rails 11 are laid along the sides
of the chamber to guide the wheels 12 of the carriages 13, and these rails are by
preference placed with a slight inclination downwards from the end (at the left-
hand side in Figure 1), at which the carriages 13 are entered to the opposite end,
where they pass out. Along the lower part of the chamber there are placed metal
pipes 14, which are filled with steam to furnish the required heat, the steam
entering them by inlet pipes 15 at one end, whilst pipes 16 are connected to the
other end to lead off water due to condensation. The steam-heated pipes 14 are
covered by a casing 17, which is divided internally by transverse partitions 18 into
four or other suitable number of compartments or sections. At one end of each
compartment there is an inlet opening 19 for air through the floor 8, and at the
other end there is a port 20, through which the air passes from the casing 17 into

page_text: the chamber, each current of air being heated by passing over and along the steam-
heated pipes 14 in the compartment through which it proceeds. On the roof 7 of
the chamber there is constructed an outlet duct or flue 21, which communicates at
the end 22 near the entering end of the chamber with a duct leading to a chimney,
or, as we prefer, to a fan or other apparatus arranged to exhaust the air. The
clamber communicates with the outlet duct 21 by ports 23 corresponding to the
ports 20 in the casing below, but placed respectively nearer the entering end of
the chamber, so that the several currents of heated air may pass generally in
inclined directions upwards towards the entering end. The several ports or
openings 19, 20, 23, for the ingress and egress of the air are fitted with slides
or valves, which can be separately adjusted so as to regulate the currents of air in
different parts of the apparatus, as may be found most advantageous in practice.
A suitable rapidity of the air currents is obtained by employing a fan or blowing
apparatus of adequate power, whilst the temperature is regulated by suitably
adjusting the supply of steam or other heating agent, which may if found desirable
be done so as to maintain a higher temperature at one end or part of the chamber
than at another.
If the sugar is in such a form as to be free from powder it may be placed on
perforated plates 24 arranged as shelves in wheeled frames or carriages 13; or the
perforated plates may be placed as shelves on guide supports fixed in the chamber.
We prefer to employ the carriages 13, as they afford facility in entering and
removing the sugar into and from the drying chamber, besides having other advan-
tages. The drying chamber is by preference arranged to contain a number of the
carriages 13 in line, and the carriages can be put in and taken out singly or in sets
at such intervals as to allow each carriage to be in the chamber just as long as
may be requisite for the best treatment of the sugar carried by it. Each carriage 13
is in the form of a light iron framework. mounted on wheels 12, and provided with
supports for the perforated plates 24, which are constructed and fitted so that they
can be removed from the carriage to facilitate the placing of the sugar on them and
the removing of it after having been dried.
Unperforated plates or trays may be employed instead of the perforated plates (24),
particularly when the sugar is in the condition of small crystals or powder; but
when dealing with sugar in that condition we prefer to employ travelling bands
with lateral rims, or plates or trays arranged to move continuously or intermittently
through the drying chamber. Figures 4 and 5 on Sheet 2 of the Drawings show a
modification with travelling bands 25. These bands 25 pass round end rollers
26, 27, one or both of which may be driven, and other rollers 28 are arranged at
intervals to support the bands in a horizontal position, or nearly so.
The drying
chamber 6, 7, is made with ends 29, which are almost entirely closed, the bands 25
passing through slits at the entering end (which is at the right-hand side in
Figure 4) to the end roller 26, which is outside at that end. The sugar is supplied
to each band 25 through a hopper 30, arranged outside to allow of the sugar being
conveniently spread on the band. The bands 25 are made of rubber, or canvas, or
other suitable material, and are formed with raised rims at the edges, which are
made of rubber or otherwise so as to be capable of passing conveniently round the
end rollers 26, 27. As the sugar is carried along by the band it passes under
rakes 31 arranged at intervals, and is by them stirred or turned over, the prongs of
the several rakes being placed in different positions so as to act on fresh portions
of the sugar in succession. At the delivery end the end roller 27 is entirely within
the drying chamber, and the sugar falls down from the band 25 as the band turns
round the roller, a rotating brush 32 being applied to insure the complete removal
of the sugar from the band. The sugar falls into a vertical passage 33, which is
fitted with two slides or valves 34, 35, one of which is kept shut when the other
is opened, and thereby cold air is prevented from entering. The arrangements for
heating the air and for regulating the several portions of the currents are the same
as in the first modification hereinbefore described. Two or more bands or sets of

page_text: plates may be arranged one above the other or alongside of each other inside of the
same drying chamber.
With these arrangements the sugar to be dried is continuously subjected to a
continually changing atmosphere, and it rapidly parts with its moisture without
becoming conglomerated into lumps or cakes. The apparatus is well adapted for
the preparation of "granulated" sugar, in which case the sugar after being dried
may if thought desirable be passed between rollers to break down any slight
agglomerations, but not so as to crush the grains or crystals, and afterwards it may
be sifted and filled into packages.
Having thus particularly described our said Invention and the manner of per-
forming 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 and in terms of the herein-
before in part recited Letters Patent is,-
1. The improved process of drying sugar in the form of plates, sticks, pieces,
crystals, grains, or powder by causing rapid currents of heated air to act on it,
substantially in the manner herein before described.
2. The combining of a drying chamber with adjustable inlets and outlets for air
in connection with a fan or other current producer, and also with apparatus for
heating the air by means of heated metallic surfaces, the parts being arranged and
operating substantially as and for the purposes hereinbefore described.
3. The elongated drying chamber combined with carriages, endless bands, or
equivalent means for moving the sugar gradually or step by step through the
chamber, and with two or more adjustable inlets and outlets for currents of heated
air, the parts being arranged and operating substantially as hereinbefore described.
In witness whereof, I, the said Thomas Robertson Ogilvie, on behalf of the
said Alexander Scott, junior, Joseph Duncan Scott, and myself, have
hereunto set my hand and scal, this Ninth day of January, in the year of
our Lord One thousand eight hundred and eighty two.
30
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
THOMAS ROBERTSON OGILVIE. (L.S.)