Improvements in, or connected with, Means, or Apparatus, for Withering and Drying, Tea or other Produce.
Year: 1896

page_text: Date of Application, 10th Aug., 1896
Complete Specification Left, 10th June, 1897-Accepted 10th, July 1897
PROVISIONAL SPECIFICATION.
Improvements in, or connected with, Means, or Apparatus, for
Withering and Drying, Tea or other Produce.
I HEW STEVENSON, of Dryden Chambers, 119 Oxford Street, in the County of
London, Engineer, do hereby declare the nature of this Invention (which has been
communicated to me from abroad by JAMES SHANNAN STEVENSON of Rothes, Hatton,
Ceylon, Tea Planter) to be as follows:-
The object of this Invention is to provide means whereby the withering and
drying of tea or other produce, can be effected with facility the said Invention being
especially adapted for use in places where it is difficult to obtain the requisite wood,
or other fuel, for a fire. According to this Invention electricity is employed as the
means for obtaining the requisite heat, as electricity can be obtained from water
power, or other source, which is frequently available where the requisite amount of
fuel for maintaining a fire is not available. The requisite electrical energy can be
obtained by any suitable means; such, for instance, as dynamo-electrical machines,
either direct or alternating current machines, driven by a turbine, or water wheel, or
by other suitable engine; or the said energy may be obtained from primary, or
secondary, electric batteries. The electric energy obtained is, converted into heat by
any suitable means such for example as by passing the current through a high
resistance, or by the electric arc, or an electric furnace. The conductor of high
resistance if such be used may be wound or otherwise disposed upon frames, rods,
trays, or other bodies, which are arranged to act as radiators for the heat. The said
conductor may be bare, or insulated, or embedded in clay, enamel, or the like.
air may be passed in contact with the electrically heated bodies and thence conducted
over, or through, the tea, or other produce, to be dried, and it may be caused to
travel either by its natural movement due to its heat, or under the influence of
forcing, or exhausting, devices. Or the heated bodies may be situated inside the
drying, or withering, chamber itself, the tea, or other produce, being passed
there through by trays, or conveyors, or it may be dropped through the air so heated,
or the tea, or other produce, may be placed directly upon the plates, or the like
bodies, which are heated by electricity as aforesaid. The mechanism of the drying,
or withering, machine may be driven by the means which are employed to effect the
heating and the same means may in addition supply light for the factory in which the
machines are situated.
The
Owing to the absence of products of combustion the quality of the tea is not
affected injuriously, and there is great cleanliness and absence of dust, and saving of
labour, and general economy, and the temperature can be regulated very readily and
perfectly.
1000

page_text: Improvements in, or connected with, Means, or Apparatus, for
Withering and Drying Tea, or other Produce.
I, HEW STEVENSON, of Dryden Chambers, 119 Oxford Street, in the County of
London, Engineer, do hereby declare the nature of this Invention (which has been
communicated to me from abroad by JAMES SHANNAN STEVENSON of Rothes, Hatton,
Ceylon, Tea Planter) and in what manner the same is to be performed to be particularly
described and ascertained in and by, the following statement:-
The object of this invention is to provide means whereby the withering and drying
of tea, or other produce, can be effected with facility, the said invention being
especially adapted for use in places where it is difficult to obtain the requisite wood, or
other fuel, for a fire.
According to this invention electricity is employed as the means for obtaining the
requisite heat, as electricity can be obtained from water power, or other source, which
is frequently available where the requisite amount of fuel for maintaining a fire is
not available. The requisite electrical energy can be obtained by any suitable means;
such, for instance, as dynamo-electrical machines, either direct or alternating current
machines, driven by a turbine, or water wheel, or by other suitable engine; or the
said energy may be obtained from primary, or secondary, electric batteries. The
electric energy obtained is converted into heat by any suitable means such for
example as by passing the current through a high resistance, or by the electric arc,
or an electric furnace. The conductor of high resistance if such be used may be
wound or otherwise disposed upon frames, rods, trays, or other bodies, which are
arranged to act as radiators for the heat.
The said conductor may be bare, or insulated, or embedded in clay, enamel, or the
like. The air may be passed in contact with the electrically heated bodies and thence
be conducted over, or through, the tea, or other produce, to be dried, and it may be
caused to travel either by its natural movement due to its heat, or under the influence
of forcing, or exhausting, devices. Or the heated bodies may be situated inside the
drying, or withering, chamber itself, the tea, or other produce, being passed
therethrough by trays, or conveyors, or it may be dropped through the air so
heated, or the tea, or other produce, may be placed directly upon the plates, or
the like bodies, which are heated by electricity as aforesaid. The mechanism of
the drying, or withering, machine may be driven by the means which are
employed to effect the heating and the same means may in addition supply light
for the factory in which the machines are situated.
Owing to the absence of products of combustion the quality of the tea is not
affected injuriously, and there is great cleanliness and absence of dust, and saving of
labour, and general economy, and the temperature can be regulated very readily and
perfectly.
In the accompanying drawings I have illustrated arrangements according to this
invention, but I wish it to be understood that I do not limit myself to the precise
details shewn in these drawings.
Figure 1 is an elevation half in section and Figure 2 is a vertical section at
right angles to Figure 1 shewing the application of the invention to a stationary
withering or drying apparatus. Figures 3 and 4 shew two kinds of trays therefor.
Figure 5 is a part of the apparatus shewing a modification and Figures 6 and 7
shew a rotary machine with the invention applied thereto.
In the arrangement Figures 1 and 2 the outer casing a is preferably made of iron
lagged outside with a good non-conductor of heat.

page_text: The electrical heaters are constituted by radiator plates b mounted on metallic
supports in the lower part of the casing, and consisting of perforated metal (say
cast iron) upon which are embedded in insulating material wires of high resistance
connected with a generator of electricity. The electrical circuits (of which there
may be any number) are arranged in parallel and are connected with the regulating
switch k by means of which any one, or more, of the said circuits may be cut
out and the heat reduced accordingly.
Air enters through openings which can be regulated by dampers c. The air by
passing through the perforations in the radiator plates is heated thereby and then
passes over or through the tea or other produce on the trays or supports d eventually
escaping by the chimney n which may be of any required height to ensure sufficient
draught. An exhausting fan can be attached to it if necessary. The arrows show
the course of the heated air.
The trays d lie one above another in the upper part of the chamber a.
The trays
shewn in Figure 3 are made preferably of iron and have solid bottoms to prevent dust
falling upon the radiator plates b. The bottoms of the trays project at one side and
the part so projecting is perforated as shewn at d³ for the passage of the air. One of
the sides of each tray is cut down as shewn at d for the same purpose.
The trays
are placed in the machine with the projecting bottom alternately right and left as
shewn on Figure 1. In this case the lowest tray has the openings on the left hand
side, the tray immediately above it on the right hand side, and so on. It will be
seen that the heated air from the radiator plates 6 heats the bottom of the lowest
tray, then passes through the perforations d in the extension thereof and through
the openings at d2 and over the surface of the tea or produce in this tray, at the same
time heating the bottom of the second tray. It then passes through the openings d¹
and d of this tray, over the ten or produce therein, and so on until it has passed
over the surface of the whole of the tea, or produce, in the several trays and
eventually it escapes to the chimney n.
The trays may he arranged and mounted in any suitable way. In the apparatus
shewn there are four spoke-wheels (e) mounted in pairs on spindles which are geared
together by a belt or chain e'. These spoke-wheels & take the weight of the remaining
trays while the lowest one is being removed. They may also be used to raise the
trays so that one may be put in at the bottom. This gear is operated by the
hand-wheelf on one of the shafts.
The tea or produce may be put in at the top of the chamber on the trays through
the door h and is gradually passed by any usual or suitable means down until it
reaches the lowest tray at the hottest part of the chamber, when it is withdrawn.
In Figure 2 the lowest tray is shewn partially withdrawn the second tray being
shewn in Figure 1, resting upon the spoke-wheels e. When the lowest tray is
completely withdrawn the band-wheel ƒ is turned and the tray so supported takes the
lowest position. A tray of fresh tea or produce is then put in through the upper
door h. If it be desired to put back the bottom tray into its original position the
hand-wheel f is turned in the opposite direction, with the result that the spoke-wheels
take the weight of the trays above, lifting them to make room for the admission of the
tray through the lower door i. The projecting bracket Figure 2 carries a table l
on which the tray which is being removed may be rested.
A thermometer for taking the temperature of the heated air is shown at (g).
The plates or heaters b can be put into position, or be examined through the
door m.
In place of trays with solid bottoms trays with reticulated or perforated bottoms d'
Figure 4 may be employed arranged as in Figure 5. In this case the heated air
passes through the tea or produce instead of over it.
As dust is liable to fall through the reticulations or perforations in the trays, dust
catchers p are arranged as shewn in Figure 5. The dust collecting in the channels
formed by these catchers may be removed by a door at either end of the chamber a.
Figures 6 and 7 are respectively a longitudinal section and a transverse section of a
rotary machine with this invention applied thereto.

page_text: Upon the standards p is mounted a stationary hollow shaft g upon which is
supported the outer stationary chamber a which may be made of wooden sides carried
by cast iron end pieces a² connected to the shaft q by the bracket arms a³. Inside
this outer chamber a and fitting it closely at the end revolves the inner chamber d
made up of perforated or reticulated trays mounted on an iron framework, having six
short arms di projecting at the angles to " tumble" the tea or produce. One of the
sides of the inner chamber de constitutes a door for the introduction and discharge
of the tea or produce. Two doors are provided in the outer chamber a one at the top
and the other at the bottom for the same purpose.
The inner chamber d' is rotated at a suitable speed by power conveyed to the
pulley (as shewn at the left hand end of Figure 6) from an electric or other motor,
by means of a rope or other suitable gearing.
On the stationary shaft q is fixed rigidly the electric heat generator b which is
shewn as consisting of a metallic tube perforated at top and with high resistance wire
wound round and insulated from it. The electric current is conveyed to the said heat
generator b by means of conductors a which pass through the hollow shaft q. The
regulation of the heat may be controlled in the manner described with regard to the
apparatus Figures 1 and 2. A deflector plate t is rigidly fixed above the openings in
the heat generator b to protect them from the falling tea, or other matter, and to
throw down the heat to the tea or produce lying on the bottom of the inner
chamber d
The air at atmospheric temperature enters the inner chamber through the hollow
shaft q passing through holes q in it to the inside of the heat generating tube b. It
then passes through the openings at the top of the said tube b and enters the inner
chamber d² under the deflecting plate t coming in contact with the falling tea or
produce. The air now passes through the perforated or reticulated walls of the inner
chamber d into the outer chamber a and thence passes out through an opening a' at
the top of the chamber a.
The air can be forced or drawn along through the hollow shaft and the interior of
the apparatus by any suitable fan or pump.
In the arrangement shewn at the right hand side of Figure 6 the air is forced into
the hollow shaft q by means of a fan u mounted on the boss of the chamber d² and
driven by gearing wheels from the pulley which rotates the inner chamber d².
At the left hand end of Figure 6 is shewn a simple arrangement of air inlet and
driving pulley. It will be understood that although in this Figure 6 I have shewn
two alternative arrangements either is to be used as desired.
To charge the machine. Open the door at the top of the outer chamber a and
turn the inner chamber d² round until its door comes opposite to that in the outer
chamber and then introduce the tea or other produce to be treated. After it has been
sufficiently dried open the door at the foot of the outer chamber a when the dust
which has found its way through the perforated or reticulated sides or trays of the
inner chamber d will fall out. When this has been done turn the inner chamber d
round until the door in it comes opposite that in the lower part of the outer
chamber d and open it when the tea or other produce will fall out. A few revolutions
of the inner chamber d will free any tea, or other produce which may remain on the
arms d³.
A thermometer to indicate the temperature of the internal air may be placed as
shewn at or it may be inserted through the hollow shaft g.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
1. The combination with means, or apparatus, for withering, or drying, tea, or
other produce, of an electric heater substantially as hereinbefore described.
2. The general arrangements and combinations of parts constituting electrically
heated apparatus for drying tea, or other produce, substantially as hereinbefore

page_text: described and respectively illustrated in Figures 1 and 2 and 6 and 7 of the
accompanying drawings.
Dated this 10th day of June 1897.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.