Apparatus for Drying Coffee, Cocoa, Spices, and the like.
Year: 1894

page_text: Date of Application, 17th May, 1894
Complete Specification Left, 16th Feb., 1895-Accepted, 11th May, 1895
PROVISIONAL SPECIFICATION.
Apparatus for Drying Coffee, Cocoa, Spices, and the like.
I EDWARD ROBINSON of 4 Castelnau Gardens Barnes in the County of Surrey,
Merchant do hereby declare the nature of this invention to be as follows:-
The apparatus employed for carrying this invention into effect. is made on a
small scale for working by means of hand power, & also on a larger scale to be
worked by horse gear, steam, or other suitable motive power, the construction being
somewhat modified according to the weight to be carried, & the amount of work to
be done. The essential features & aims are common to both arrangements. The
smaller adaptation is constructed mainly as follows :-
A stove or fire box is made of any convenient pattern, with a flue, or chimney, of
any required length & diameter. Around the fire box & flue is placed a water
jacket adapted to contain a suitable quantity of water, so that all parts of the
heater & flue, in such proximity to the fire as to render them liable to become too
bot are surrounded by the water jacket. The jacketed flue extending away from
the fire box may conveniently be put in a horizontal position, & at the terminal end
of it, or thereabouts, may be placed a small box, serving partly to hold a sufficient
supply of water, & also as a steam chest, to be more particularly mentioned here-
after. A return pipe, or pipes may be fixed into the water jacket surrounding the
Blue, or into the end tank just mentioned, in order to ensure a good circulation of
bot water from the fire hox end, & back again. After passing through the water.
jacket & tank the smoke flue may, if required be bent round again, & made to
return towards the stove end. This return flue can either be enclosed in a water
jacket, as before described, or if expedient, its heating surface can be utilised
without the water jacket, as, being some distance from the fire its heat ceases to be
very great. In either case openings must be provided for sweeping out the flue.
At the top of the fire box a suitable space is left for a steam chest as well as at the
tank end before alluded to, & escape pipes are inserted into both these chambers,
so as to ensure a free escape of the steam. Surrounding the water jacketed stove,
or fire box, is an air jacket, or annular space, & a similar jacket is put round the
tank, the bend of the flue, & other heating surfaces at the opposite end. The use
of these air jackets will presently be explained in connection with the arrangements
for treating the material to be dried, which for the smaller scale of working are
somewhat as follows
A cylinder made of wire-work, or other suitable material, is, constructed of
sufficient strength to carry the required weight, & it may either revolve on an axis,
5 or spindle in the center, or upon friction rollers placed underneath. This cylinder
is divided into three or more compartments of equal size, & a narrow door, or lid
running the whole length of the cylinder opens into each compartment, for putting
in & letting out the material under treatment. Each compartment, or division,
is furnished with one or more shelf-like constructions running horizontally through
0 the compartments, placed at a suitable angle or tangent, so that when the cylinder
is revolved the material is carried upwards & allowed to trickle down, so as to keep
it in motion constantly turning over, & exposing tresh surfaces to the drying action
of the heated air. A cylinder of this or similar description is enclosed in a
stationary box, or chamber made of wood, or other suitable material, & having just
5 room enough inside to allow the cylinder to revolve. The lower part of this
stationary chamber, or box, is made also to enclose the heating part of the
apparatus, consisting of water jacketed stove, flue, & other heating surfaces before

page_text: described, & the revolving cylinder carrying the material to be dried, is made to
work in near proximity to the heating surfaces. The upper part of the stationary
chamber is made, by preference, somewhat converging, & a funnel, or other suitable
opening, or openings is provided to allow the vapour to escape.
The before mentioned air jackets, are placed round the fire box, & another about
the bend of the flue & other heating surfaces at the opposite end, are connected to
openings in each end of the drying chamber, so that the air passing into the chamber
is heated by being admitted only in thin streams, in close contact with heating
surfaces at each end of the apparatus.
A steam pipe is inserted in the steam chest over the fire box, & a similar one in
the steam chest at the opposite end, & these two pipes are carried upwards through
the drying chamber, & made to discharge their steam into the lower part of a
ventilating pipe or funnel, at the top of the chamber. They may either be carried
up separately, blowing their steam into separate ventilators, or the two pipes may
be conveyed into one funnel, as required. By this means the steam escaping from
the heater is made to act as a steam jet inducing a considerable volume of air &
vapour, which is drawn out of the drying chamber, a current of air, or draught
being established between the funnel or funnels, & the inlets provided by the air
jackets at opposite ends, as described.
It will be understood however that the foregoing arrangement of the apparatus
is most suitable for drying comparatively small quantities at a time, & that where
large quantities-say a ton or more-have to be dealt with at once, a stronger
construction of the machine is needful, & also larger volumes of heated air must
be provided than can well be induced by a jet of steam. In this case the revolving
cylinder with its three or more divisions or compartments, each having stirring &
separating shelf-like devices, supplemented if necessary by tines, or teeth &c. as
before described, may have its outer shell or periphery made of wood, or sheet iron,
instead of wire, or perforated work. The stationary chamber may then be dispensed
with, & the heated air may be drawn, or driven through the heater by means of a
fan, & blown into the revolving cylinder. For this purpose the air jacket, or
annular spaces may be continued the whole length of the heating tubes, & may be
made to enclose the whole of the heating surfaces before described. These water-
jacketed & other tubes, may be made to pass through the blades of a spiral, or
Archimedean screw, so as to prolong the travel of the air in contact with heating
surfaces, thus more effectually heating the larger volumes of air required for
drying the greater quantities of material contemplated by this arrangement of the
machine.
The heated air thus obtained is blown into a stationary pipe passing through
the center of the revolving cylinder. This stationary pipe is provided with a
series of nozzles placed at suitable intervals apart, & by preference directed down-
wards. From these orifices the air is blown into & among the material being dried,
the material being kept in motion continually exposing fresh surfaces to the action
of the wind as the cylinder revolves, carrying round with it the stirring &
separating appliances before described. For loading & discharging the cylinder,
the same arrangement of lids in the outer shell is employed, as those previously
mentioned in connection with the smaller construction of the apparatus.
Openings are provided in the ends of the cylinder for the escape of the moisture
evaporated.
The smaller of these machines are turned by hand, a cogged gearing, or other
suitable contrivance may be used. The larger ones may be worked by means of a
horse or mule gear, or steam, water, or any convenient motor can be employed, as
indicated in the outset. These larger cylinders can also be made to turn on a
spindle, or pivot in the center, or upon friction rollers as may be found most
convenient.
Dated this 17th day of May 1894:

page_text: in the bottom of the stationary chamber M, admitting air in close contact with the
flue pipes D.
The use of these air inlets will presently be explained in connection with the
arrangements for treating the material to be dried, which for the smaller scale of
working is somewhat as follows:-—
A cylinder made of wire-work or other suitable material, see I Fig. III & V, is
mounted on a frame J & it may either revolve on an axis, or spindle in the centre,
or upon friction wheels as shown at K in Fig. VI. The cylinder is divided into
three or more compartments of equal size-see 1. Figs. V & VII. A narrow
door, or lid opens into each compartment, for putting in & letting out the
material under treatment. Each chamber, or division is furnished with one, or
more shelf-like construction C Figs. V & VII, running the whole length, & placed
at such an angle, or tangent as to carry the material upwards, & allowing it to
trickle down as the machine revolves, thus keeping the material in motion, &
constantly exposing fresh surfaces to the action of the heated air. A cylinder of
this, or similar description is enclosed in a stationary box made of wood, M Figs. I
& 11. Such box, or chamber is also made to enclose the heating part of the
apparatus as shown in Fig. I, & the revolving cylinder, carrying the material to be
dried is caused to work in near proximity to the heating surfaces before described.
A funnel for the escape of the moisture is placed at the top of the drying
chamber a Figs. I & II as shown.
The before mentioned air jackets around the fire box G & other heating
surfaces H are all made to open into the stationary drying chamber Fig. I so as
to heat the air as it is admitted.
A pipe F is inserted in the steam chest over the stove A Fig. 1, & another in
the steam chest over the water tank C, & these pipes are carried upwards through
the stationary drying chamber & made to discharge their steam into the lower part
of a ventilator, or funnel a at the top of the chamber. Such steam pipes as these
may be discharged into one or more ventilators at pleasure. By this means the
steam escaping from the heater is made to act as a jet inducing a considerable
volume of air & vapour which is drawn out of the drying chamber, a strong
current of air being established between the ventilating fannel or funnels, & the
inlets provided by the air jackets at opposite ends as described.
It will be understood however that the foregoing arrangement of the apparatus
is most suitable for drying comparatively small quantities at a time, & that when
larger operations are required, a stronger construction of the machine is needful,
& also larger quantities of hot air than can well be reduced by means of a small
jet of steam. In this case the revolving cylinder I with its three or more
divisions L or compartments, each having stirring or agitating devices C sub-
stantially as before described, may have its outer shell, or periphery made of
wood, or sheet iron instead of wire, or perforated work. The stationary chamber M
is then dispensed with & the heated air is drawn, or driven through the heater by
a fán, or blower N & driven into the revolving cylinder. Fig. VI illustrates this
arrangement. The heater used in this case is shown in Fig. IX. It will be seen
that the air-jacket, or annular spaces G are continued the whole length of the
heating tubes D thus enclosing them within a cylindrical shell O. the tubes, being
arranged somewhat more compactly to suit this object. These water-jacketed
other tubes are made to pass through the blades of a spiral, or Archimedean screw P
so as to prolong the travel of the air in contact with heating surfaces, thus more
effectually heating the larger volumes of air required for drying the greater
quantity of material contemplated by this arrangement of the machine.
The heated air thus obtained is blown into a stationary pipe Fig. VI C, passing
through the center of the revolving cylinder D'. This stationary pipe is furnished
with a series of nozzles placed along the bottom, at equal distances apart,
pointing downwards. From these nozzles wind is blown into & among the material
being dried, as the cylinder revolves, maintaining the material in constant motion
by means of the agitators C as before described & shown Fig. VII.
For

page_text: loading & discharging the, cylinder the same arrangement of lids 6, in the outer
shell is employed as that previously mentioned in connection with the smaller
machine.
Openings are provided in the ends of the cylinder for the escape of the moisture
evaporated, see g Fig. VIII.
Having now particularly described & ascertained the nature of my said inven-
tion, & in what manner the same is to be performed, I declare that what
I claim is
The heating apparatus as described, & shown in the drawings, consisting partly
of water-jacketed heating surfaces, & partly of tubes & other heating surfaces not
surrounded by water, & provided with a steam chest, or chests, supplying a jet of
steam to act in place of a fan, for inducing a current of air, to draw off & expel
moisture, substantially as shown, together with the alternative arrangement in
which the tubes & other heating surfaces are enclosed in a shell, the air being
made to circulate round by means of a spiral, or Archimedean screw essentially as
illustrated in Fig. IX. The air in this case being drawn, or driven through the
heater by means of a fan.
The reticulated, or perforated drying cylinder enclosed in a chamber, & rotated
over, or near to, heated surfaces as shown. Divided into three or more com-
partments, each having a lid, & stirring devices. Also a similar drying cylinder,
or chamber with covered periphery, revolving round a stationary tube, having
nozzles for the equal distribution of the wind, substantially as illustrated &
described.
The air heating structures, as herein specified in combination with drying
cylinders & chambers, essentially as illustrated & described.
Dated this 16th day of February 1895.
EDWARD ROBINSON.