Improvements relating to the Drying of Coffee, Grain, Fruit, and other Materials, and to Apparatus therefor.
Year: 1894

page_text: Date of Application, 14th Dec., 1894-Accepted, 27th Apr., 1895
COMPLETE SPECIFICATION.
Improvements relating to the Drying of Coffee, Grain, Fruit, and
other Materials, and to Apparatus therefor.
I, AUGUSTO FERREIRA RAMOS, of São Paulo, in the State of São Paulo,
Republic of the United States' of Brazil, Civil Engineer, do hereby declare the
nature of this invention and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement:-
My invention relates to the drying of coffee, grain, fruit and other materials
and to apparatus therefor.
Coffee berries, as they come from the plantation after the harvest, are subjected,
after having been washed, to desiccation which has for its object to facilitate their
decortication and ensure the preservation of the beans or grains; on the manner
in which this delicate operation is carried out depends to a great extent the value
of the commercial product. Formerly this operation was exclusively effected on
platforms where the berries, spread out in layers continually turned over by hand,
remained subjected to the action of the solar heat until the desiccation had reached
the desired degree.
The improved method forming the subject of my said invention is designed to
replace the before-mentioned process which, besides its slowness, possesses great
inconveniences. Apart from the mechanical means employed for realizing it, this
method consists in submitting the coffee berries to the action of heat for a very
short period (in most cases scarcely fifteen seconds) and several times in succession
at one, two, three, four, five, six or more times longer intervals than the period
during which the heat has acted; profiting by these intervals for keeping the
berries either piled up in a heap or in a fixed hopper, or else as a thick layer in one
or more oscillating channels, in order that they may be dried uniformly not only
with regard to each other but also with regard to the mass of each of them, this
action being produced progressively from the periphery to the centre of the berries
to be dried.
In the accompanying drawings I have represented the apparatus by means of
which I carry out the method herein before succinctly set forth.
Figure 1 is a side elevation showing the general arrangement' of the' apparatus.
Figure 2 is an end elevation of this apparatus.
Figure 3 shows the same apparatus in plan.
Figures 4 to 9 are views of details.
Figure 10 represents a diagram of a particular arrangement of the apparatus.
Similar letters or figures designate corresponding parts in the several figures.
The principal parts which constitute the apparatus are a fixed hopper A, a part
made in the form of a cradle B, two elevators C, a furnace D; a fan E and a
transmitting gear F.
I divide the said hopper A into two compartments 1 and 2 by a vertical partition 3;
each of these compartments possesses an outlet orifice 4 which is provided with a
register actuated by a rack and pinion 5. Below each of these orifices is a
cylinder 6, Figures 1, 2, and 5, upon which are formed longitudinal grooves or
chaunels 7; these cylinders are keyed upon shafts 8 turning in sleeves or bearings 9
of two supports 10 secured to transverse pieces 11 of the hopper A. Each of
these shafts carries a clutch mechanism composed of a grooved wheel '12, a friction
clutch 13, clutch levers 14 and operating levers 15 these two levers being united by
the sleeve 16. The levers 15 of each of the clutch mechanisms are connected with

page_text: each other by a rod 17 and pins 18. One of the transmitting levers is prolonged
by a tail-piece 15¹.
The part B, Figures 1, 2, 3 and 6, is composed of a cradle 19 made of sheet
metal and carrying over its entire length a partition 20 parallel to the bottom;
this partition may be formed of a perforated sheet of metal or wire-work, but is
preferably composed of parallel iron wires forming grates and leaving suitable
spaces between them. The cradle 19 is inclined in the direction of its length; its
highest extremity is closed by a sheet metal plate 21, and the opposite extremity is
likewise closed by a plate 22 which occupies the space between the lower part of
the partition 20 and the bottom of the cradle. The cradle 19 is supported by two
straps 23 whose extremities bear upon two girders 24, each possessing four forks or
cheeks 25 fixed to its lower face and in which articulate by bolts 26 the heads 27
of the oscillating supports 28 of wood secured below upon wooden pieces by the
feet 30.
Each of the oscillating supports 28 is fixed with its lower extremity in the shoe 30
secured by bolts to one of the wooden basement pieces of the apparatus. This
support is in reality a spring which, being fixed at one of its extremities in the
shoe 30, oscillates, by following the alternate movement, transmitted to it by the
longitudinal beam 24, to which it is articulated.
At the lowest end of the cradle 19 are two channels 31¹ which, being inclined
symmetrically with regard to the vertical axis of the craille 19, project laterally
beyond this cradle 19 and have their open extremities 30¹ terminating above the
hoppers 31 of two elevators C; these elevators are operated at their upper part by
a common shaft 32, a pair of toothed wheels 33, 35 and a small intermediate
shaft 34 carrying a pinion 35 and pulley 36. The buckets 37 discharge their
contents into channels 33 whose lower extremities 39 are arranged as shown in
Figure 3, so that the coffee berries which slide down upon the part 391 may be
thrown into the compartment 1, and that the berries which slide down upon the
part 40 may fall into the compartment 2 of the aforesaid hopper A.
The furnace D designed for heating the air is composed of two contiguous
chambers 41 and 42, Figures 1 and 3. In the chamber 41 is provided the fire-place
with its door 42' and grate 43; below the grate are parallel flues 44 formed by small
brick walls 45 upon which bear edgeways and in parallel rows the bricks forming
the grate 43 and leaving between their rows free spaces 46 opening upon the
flues 44, through which the flames from the furnace, urged on by the artificial
draught from the fan, will heat the flues 44 which conduct the atmospheric air into
the chamber 42; in this chamber are deposited the cinders and soot carried away by
the air and by the gases leaving the fire-place; these materials accumulate in the
basin 47 whence they are removed through the door 48. At the height where the
vault of the chamber 42 commences and in the wall 49 are provided openings 50
in which terminate the conduits 51 which extend to the lateral openings of the
fan. The outlet conduit 52 of the fan has its extremity 53 passing with the least
play possible into a sleeve 54, Figure 6, fixed to the plate 20. This play is that
strictly necessary for enabling the sleeve to be displaced in its alternating
movement without touching the pipe 53. The fan is actuated by the pulley 55.
Motion is transmitted to the apparatus by the shaft 56 bearing upon two
standards by its journals 57 and carrying a pulley 58 which receives its motion from
the motor and is keyed upon the shaft 56; a pulley 59 actuating the pulley 55 of
the fan; a
pulley 60 actuating by the pulley 36 the elevators; and at its extremity
a disc 61 with an adjustable crank pin 62, Figure 7, for giving to the part Ba
straight horizontal alternating movement through the medium of a connecting
rod 63, Figure 1, whose head receives the crank pin 62, and whose other extremity
fits between the lugs of a fork 64 Figure 9 traversed by a bolt 63* and which is
fixed to the lower portion of the part B.
I impart motion to the clutch mechanism which operates the distributing
cylinders 6, Figures 1, 4 and 5, by means of a connecting rod 65 attaching one
of the longitudinal girders 24 to the tail-piece 15' of the lever forming one piece

page_text: with the clutch lever 14. The longitudinal girder carries for this purpose a pin 66,
and the tail piece 15¹ a pin 67 adapted to be displaced in a slot 68 for enabling the
amplitude of the movement of the clutch levers to be regulated.
My improved apparatus operates in the following manner: The coffee berries to
be dried being placed in the two compartments of the hopper, and the outlet
openings 4 being suitably regulated by their registers provided with racks and
pinions 5, the apparatus is set in motion by actuating only one of the distributing
cylinders 6 which receives the berries at its upper part and lets them fall upon the
grate 20 of the cradle 19 to which an oscillatory movement is imparted in its
longitudinal direction, produced by the adjustable crank pin 62 and the connecting
rod 63 articulated upon the fork 64 secured to the lower end of the cradle.
When the grate 20 is charged with a sufficiently thick layer of berries I set the
fan in operation; the furnace having previously been ascertained to be in a state
for supplying air at the desired temperature.
By means of the fan the air is driven below the grate 20 where, owing to the
pressure acquired, it will traverse the layer 69 by the interstices between the
berries forming such layer and raise its temperature which gradually increases
until the berries pass in their displacement along the grate 20 to the channels 31
which they traverse and then fall into the hoppers 31 of the elevators.
This passage of the berries upon the grate along the cradle is effected by reason
of the inclination of the latter combined with the oscillatory movement caused by
its oscillating supports 27, a movement whose amplitude may be regulated by the
adjustment of the crank pin 62, thus enabling the coffee to be kept exposed upon
the grate to the action of dry and hot air for a suitable time.
The resistance due to the friction of the air which tends to escape through the
very narrow annular space between the sleeve 53 and the tube 54 is sufficient for
allowing it to acquire below the grate 20 the pressure which is necessary for
overcoming the layer of berries which is in motion on the grate..
As the berries arrive in the hoppers 31 of the elevators they are taken up by
the buckets and distributed simultaneously to the two compartments of the upper
hopper through the channels 38 whose extremities are suitably arranged for this
purpose. I employ two elevators in order that the coffee berries may be
distributed uniformly on their arrival in the hopper.
When the compartment of the hopper corresponding to the distributing cylinder
in motion is completely empty I stop this cylinder and set in motion the cylinder
corresponding to the second compartiment, so that the movements of the clutch
mechanism may be independent of each of them. When in its turn this second
compartment is empty I proceed again with the first and so forth to the end of the
operation which is terminated when the product reaches the desired degree of
desiccation.
In case the precaution should not be taken of completely emptying each of the
compartments of the hopper in their turn, currents are liable to be formed in the
mass of the accumulated product, which currents would favour the descent of
the berries situated in the mean perpendicular zone of the compartments to the
detriment of those which, being near the sides, might become completely
immovable during their passage towards the outlet orifice.
When I stop one of the distributing cylinders corresponding to one of the
compartiments which has just become empty it is not necessary to close the register
of the corresponding orifice for keeping in this compartment the coffee berries
which will be thrown into the same again, because the distributing cylinder, on
being stopped, fulfils the function of an obturator.
While in the upper hopper A, where they bring all the heat which they have
been able to accumulate in their passage upon the grate of the cradle, all the
berries will acquire a uniform degree of heat so that their desiccation will take.
place uniformly, not only with regard to each other, but also with regard to the
mass of each of them taken separately, in which the desiccation takes place from
the periphery to the centre.

page_text: Instead of employing a hopper A of large dimensions I may provide a device,
as shown in diagram Figure 10,, which comprises two parallel cradles 70. and 71
similar to the cradle B already described, and receiving an identical movement;
these two cradles are inclined longitudinally in opposite directions to each
other, one being in communication with a fan 72 introducing hot air into the
same, and the other with a fan 73 supplying air at the surrounding temperature
thereto.
The coffee berries to be treated are placed in layers upon the grates on which
they travel; those in the cradle 70, on reaching its lower extremity, are received
in the hopper 74 of an elevator 75 which raises them and brings them to the
highest part of the grate of the cradle 71, whilst the coffee berries which travel
upon the grates of the cradle 71, having arrived at its lower extremity, are thrown
into the hopper 75 of an elevator 76 which raises them and brings them to the
upper part of the grate of the cradle-70, so that the whole mass of the product to
be dried passes successively through the two cradles, being subjected.now to the
action of the hot air and now to the air at the surrounding temperature.
The desiccation of the product exposed to these alternating temperatures is
effected in a regular and rapid manner; it would likewise be effected if the action
of the fan 73 were dispensed with, but it would then require more time for
reaching the desired point.
I may close the upper part of the cradle 19 so that the air which has traversed
the layer 69 travelling upon the grate 20 may be taken up and utilized again so as
to profit by the heat which it still possesses.
For distributing the coffee to the compartments of the hopper I may also employ
registers which are arranged in the channels of the elevators.
Instead of being in a straight line in its longitudinal direction the part B may
be arranged in a zig-zag line, the alternating movement being in this case imparted
to the same in the transverse direction.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to he performed, I declare that what I
claim,is:
-
First. A method of drying coffee berries, also applicable to the desiccation of
other berries and grain, fruit or any material in a similar state of division, which
consists in subjecting the berries or the like forming a thick layer upon the grate
or screen of a cradle to the action of currents of dry and hot air, which constantly
traverse the said layer through the interstices between the berries continually
agitated by the longitudinal oscillatory movement of the cradle along which, as
they are displaced, they remain subjected to the action of the heat only for a
very short period and several times in succession at one, two, three, four, five, six
or more times longer intervals than the period during which the heat has acted;
these intervals being utilized for keeping the berries either piled up in a heap or
in a fixed hopper or else as a thick layer in one or more oscillating channels in
order that they may be dried uniformly not only with regard to each other, but
also with regard to the respective mass of each of them, this action being
produced progressively from the periphery to the centre of the berries to be dried,
substantially as herein before set forth.
Second. A drying apparatus comprising a fixed hopper, a cradle, two.elevators,
a furnace, a fan and transmitting devices setting the operative parts in motion,
substantially as bereinbefore set forth.
Third. In drying apparatus a hopper divided into two independent compartments
possessing each au outlet orifice controlled by a register with a rack and pinion,
and corresponding to a feed cylinder having longitudinal grooves or channels and
fulfilling, when stopped, the part of an obturator o the aforesaid outlet orifice,
the two feed cylinders which correspond to the two outlet orifices of the compart-
ments of the hopper being adapted to work either separately or simultaneously,
and being operated by independent clutch mechanisms actuated by the alternating

page_text: movement of the part presenting the form of a cradle, substantially as hereinbefore
set forth.
Fourth. In drying apparatus a part made in the form of a cradle, with a
longitudinal partition constituting a screen or grate, two straps, two lateral girders
provided with forks and oscillating supports of wood whose cast-iron heads fit and
articulate between the lugs of the said forks, and a transverse channel at the
extremity of the cradle, substantially as herein set forth.
Fifth. In drying apparatus two elevators with channels whose extremities are
arranged so as to permit of the simultaneous distribution of the raised materials
to the two compartments of the hopper, substantially as hereinbefore set forth.
Sixth. In drying apparatus a furnace composed of a fire-place, a depositing
chamber in the fire place, a grate whose intermediate spaces communicate with
lower flues at a right angle to the said grates; in the depositing chamber being
provided a basin and cleaning door, substantially as herein before set forth.
Seventh. In drying apparatus a fan drawing hot air into the chamber of the
furnace and forcing it below the grate of the cradle through a pipe whose
extremity passes with very little play into a sleeve forming one piece with the
metal plate at the extremity of the said cradle, substantially as hereinbefore set
forth.
Eighth. In drying apparatus a general transmitting shaft setting the operative
parts in motion and having at one of its extremities a disc carrying an adjustable
crank pin for moving the cradle by means of a connecting rod, substantially as
hereinbefore set forth.
Ninth. In drying apparatus, as a substitute for a large cradle, the employment
of a second cradle similar to the first and which may be put in communication
with a fan forcing air below the grate at the surrounding temperature and two
elevators, substantially as hereinbefore set forth with reference to Figure 10 of
the drawings.
HASELTINE, LAKE & Co..
45, Southampton Buildings, London, W.C., Agents for the Applicant.