Improvements in Apparatus for Subjecting Substances to the Action of Air, more especially intended for use in Withering or Wilting Tea Leaves, but applicable also to Drying Coffee, Grain, and other Produce.
Year: 1889

page_text: Date of Application, 21st Oct., 1889
Complete Specification Left, 1st Feb., 1890-Accepted, 1st Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Subjecting Substances to the Action
of Air, more especially intended for use in Withering or Wilting
Tea Leaves, but applicable also to Drying Coffee, Grain, and
other Produce.
1. WILLIAM JACKSON of Thorn Grove Mannofield, Aberdeen, North Britain
Gentleman do bereby declare the nature of this Invention to be as follows:-
In order to render tea leaf fit to be rolled it is necessary to make it limp or
pliable by a process called withering or wilting. This has hitherto been generally
done by spreading the leaf thinly on perforated or reticulated surfaces or trays
whereon it is allowed to remain until withered or wilted. In foggy wet or cold
weather withering or wilting in this manner is very difficult and the main object of
my Invention is to provide a machine which will effect the withering or wilting in
a rapid and efficient manner independently of climatic influences but the said
machine is also applicable to the drying of coffee, cocoa, cinchona grain or other
proluce.
The apparatus constructed according to this Invention consists of a rotating
chamber with an open periphery in combination with a travelling endless web or
band which closes the otherwise open periphery of the rotating chamber for the whole
or a greater part of its extent, means being provided for the forcing or drawing into
the said chamber of air (which may be previously heated) and for the feeding of the
leaf or other material into the circular chamber, the said chamber as it rotates and
the endless band as it moves round with it carrying the leaf or other material along
so that it is elevated in the rotating chamber by lifters and is then showered down
again on to the web or band until the withering wilting or drying is effected when
the leaf or other material may be discharged by moving the chamber and web or band
round in the opposite direction.
Whilst not limiting myself to precise details of construction the following is a
description of an apparatus constructed according to my Invention.
The apparatus consists of an endless travelling web of perforated canvas wirework
or the like and provided with a pitch chain on either side.
On a draft I mount two discs of a large diameter and at such distance apart as to
constitute between them the rotating chamber aforesaid the peripheries of the said
discs receiving the pitch chains.
These discs are placed on the shaft a distance apart equal to the breadth of the
weh so that when the web is lapped say about three fourths round the said discs
the whole will form a cylindrical chamber having an opening at the part which
the travelling web does not cover.
The web passes off the discs at the top of the opening over sprocket wheels with
which the chains engage and then back on carrier pulleys, underneath and round
sprocket wheels at the bottom of the opening (with which sprocket wheels the chains
also engage) and again passes on to the discs, thus practically forming a circular
revolving chamber having a fixed or stationary opening on one side. The discs may
be perforated or reticulated throughout all or part of their area or they may be left
solid.
For the purpose of carrying the leaves or other material up to or towards the top
of the chamber, I provide the cylindrical chamber with battens shelves or ledges
which may be fixed across between the two discs, or they may be all fixed on to the
metallic web, but. I prefer using a combination of both viz. shallow ledges or the like
on the web and broader ones between the discs.

page_text: These shelves or the like carry the leaves or other materials round from the bottom
to the top of the cylindrical chamber from whence they drop by gravitation or
shower down back on to the travelling web to be again carried up and so on until
the desired effect is obtained.
I place against the fixed opening the end of a pipe or air duct the other end of
which is connected to the discharge aperture of a blowing fan or equivalent device
by which a strong current of air (which may be heated) is forced or caused to pass
directly into the cylindrical chamber to impinge upon and circulate amongst the
leaves or other material in the circular chamber.
In some cases I may enclose the whole circular chamber in a casing and then 1
pass the air in at the fixed opening and by means of an exhaust fan attached to
another convenient opening in the casing draw or exhaust the air through the circular
casing instead of blowing it.
An aperture is made in the air duct on the top side near to the revolving chamber
and this is provided with a hopper through which the leaves or substances to be
treated are fed the strong current of air carrying them forward into the cylindrical
chamber.
When the tea leaves or other substances are sufficiently treated I reverse the
direction of rotation of the chamber and they are then rapidly discharged over the
lower end of the web.
Dated this 21st day of October 1889.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Subjecting Substances to the Action
of Air, more especially intended for use in Withering or Wilting
Tea Leaves, but applicable also to Drying Coffee, Grain, and
other Produce.
I, WILLIAM JACKSON of Thorn Grove, Mannofield, Aberdeen, North Britain
Gentleman 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 :-
In order to render tea leaf fit to be rolled it is necessary to make it limp or
pliable by a process called withering or wilting. This has hitherto been generally
done by spreading the leaf thinly on perforated or reticulated surfaces or trays
whereon it is allowed to remain until withered or wilted. In foggy, wet or cold
weather withering or wilting in this manner is very difficult and the main object of my
Invention is to provide a machine which will effect the withering or wilting in a
rapid and efficient manner independently of climatic influences but the said machine
is also applicable to the drying of coffee, cocoa, cinchona grain or other produce.
The apparatus constructed according to my Invention consists of a rotating
chamber with an open periphery in combination with a travelling endless web or
band which closes the otherwise open periphery of the rotating chamber for the
whole or a greater part of its extent means being provided for the forcing or
drawing into the said chamber of air (which may be previously heated) and for
the feeding of the leaf or other material into the circular chamber, the said
chamber as it rotates and the endless band as it moves round with it carrying
the leaf or other material along so that it is elevated in the rotating chamber by
lifters and is then showered down again on to the web or band until the withering
wiltering or drying is effected when the leaf or other material may be discharged
by moving the chamber and web or band round in the opposite direction.
In order that my Invention may be clearly understood I will describe more
particularly with reference to the accompanying Drawings arrangements according

page_text: thereto Figure 1 being a side view of a machine constructed according to my
Invention and Figure 2 being a vertical transverse section on the line 1. 2.
Figure 1. Figure 3 shews a modification of the arrangement as hereinafter
described.
The apparatus consists of an endless travelling web B of perforated iron canvas
wirework or the like and provided with a pitch chain b b on either side.
On a shaft a I mount two discs A A of a large diameter and at such distance
apart as to constitute between them the rotating chamber aforesaid, the peripheries
of the said discs being formed to receive the pitch chains so that as the chains
are moved they cause the chamber to rotate.
The said discs AA are placed on the shaft a a distance apart equal or about
equal to the breadth of the web B so that when the said web is lapped say about
three fourths round the said discs the whole will form a cylindrical chamber
having an opening at the part (at C) which the travelling web does not cover.
The said discs may be supported by the boss a³ and distance pieces a' between
which extend the spokes a³.
The web B passes off the discs AA at the top of the opening Cover sprockets
wheels D D with which the chains bb engage and then back on carrier pulleys E E
and round sprocket wheels F F at the bottom of the opening C (with which
sprocket wheels the chains also engage) and again passes on to the discs A A
thus practically forming a circular revolving chamber having a fixed or stationary
opening on one side (at C). The discs A A may be perforated or reticulated through-
out all or part of their area or they may be left solid. The pulleys and wheels are
supported by framings as shewn.
I place against the fixed opening the end of a pipe or air duct the other end of
which is connected to the discharge aperture of a blowing fan or equivalent device
by which a strong current of air (which may be heated) is forced or caused to pass
directly into the cylindrical chamber to impinge upon and circulate amongst the
leaves or other material in the circular chamber.
Grepresents the first motor shaft which drives by the bands g the sprocket
wheels and so drives the chains b. H is a fan (driven by the band g) with inlet
ath for air (which may be beated) and outlet at h² discharging the air into the drying
chamber. I is a hopper into which the leaf or other material is fed.
For the purpose of carrying the leaves or other material up to or towards the top
of the chamber, I provide the cylindrical chamber with battens shelves or ledges
which may be fixed across between the two discs as shewn at a² or they may be all
fixed on to the web B as at 2 but I prefer to use a combination of both vis. :-shallow
ledges or the like on the web and broader ones between the discs. These shelves or
th like carry the leaves or other materials round from the bottom to the top of the
cylindrical chamber from whence they drop by gravitation or shower down back on
to the travelling web B to be again carried up as the web travels and so on until the
desired withering or drying effect is obtained.
If desired the chamber may be driven instead of driving the band, the effect being
the same.
In some cases I may, as illustrated by Figure 3, enclose the whole circular chamber
in a casing and then I pass the air in at the fixed opening C and by means of an
exhaust fan attached to another convenient opening in the casing as at J, I draw or
exhaust the air through the circular casing instead of blowing it as in the preceding
arrangement.
An aperture is made in the air duct on the top side near to the revolving chamber
and this is provided with a hopper I through which the leaves or substances to be
treated are fed, the strong current of air carrying them forward into the cylindrical
chamber as in the preceding arrangement.
When the tea leaves or other substances are sufficiently treated 1 reverse the
direction of rotation of the chamber and band and the said leaves or other substances
are then rapidly discharged over the lower end of the web.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
1. In apparatus for subjecting substances to the action of air, the combination of a
rotating chamber and an endless web or band and means for creating a current of air
and for feeding in the substance to be treated, all arranged and cooperating substan-
tially as herein before described.
2. In apparatus for subjecting substances to the action of air the combination of a
rotating chamber and an endless web or band so arranged that when driven in one
direction the substances to be treated are fed into and showered down in the said
chamber and when driven in the other direction the substances are discharged from
the said chamber substantially as herein before described.
3. In apparatus for subjecting substances to the action of air, the combination of a
rotating chamber and an endless web or band with shelves or the like in the chamber
or on the band or both in the chamber and on the band, substantially as and for
the purposes herein before described.
4. The arrangement and combination of parts constituting the apparatus for the
purposes mentioned substantially as hereinbefore described and shewn in Figures 1
and 2 of the accompanying drawings.
5. The arrangement and combination of parts constituting the apparatus for the
purposes mentioned substantially as bereinbefore described and shewn in Figure 3 of
the accompanying drawings.
Dated this 23rd day of January 1890.