Improvements in and connected with Machinery for Drying Tea Leaf in course of Manufacture.
Year: 1897

page_text: Date of Application, 10th Dec., 1897
Complete Specification Left, 12th Sept., 1898-Accepted, 10th Dec., 1898
Improvements in and connected with Machinery for Drying Tea Leaf
in course of Manufacture.
I, NATILAN WILLIAM HORATIO SILARPE, of 16, Lancaster Road, Finsbury Park,
London, Engineer, do hereby declare the nature of this invention to bo as
follows:-
This invention refers to apparatus for drying tea leaf or other analogous sub-
stances and relates to both classes of machines known to the trade as hand tray
and automatic dryers respectively.
In both types as at present in use, the heated air is introduced into the drying
chamber and drawn through the leaf either downwards, upwards or at an angle.
In the downward draft type it is found that the current of heated air has neces-
sarily to be strong in order to overcome the resistance of the layers of trays upon
which the leaf rests this is most detrimental to the quality of the tea large quan-
tities of volatile constituents being lost through the blast pressure.
"
In the upward draft type where the heated air is taken in at the bottom of the
chambers and pulled upwards through the trays there is a great tendency to
what is known as "lifting, that is, the upward blast carries with it great
quantities of the finest quality of leaf known as dholegoorie" and which are
entirely lost, the heated air by being introduced into the drying chamber near
the bottom comes into contact with the partly dried tea afterwards passing to
the green or fresh roll, this is also detrimental as the partly dried tea should
be finished in a cooler temperature and the fresh roll should have the first blast
of heated air directed against it so as to effectually arrest fermentation which is
most important. The object of this invention is to overcome the above objections
which is effected by a construction of apparatus substantially as follows:-
In the hand tray types say within a rectangular chamber, is located a series
of trays arranged at a slight angle, the lower part of which is nearest the air
heater, the leaf placed on the surface of the tray is exposed to the full current of
heated air as it is drawn through the trays by the exhaust fans.
To facilitate the straight draft and to equally distribute heated air of an equi-
table temperature throughout the apparatus, I divide the rectangular chamber
into three or more divisions, in each of which the trays are placed, which reach
from one dividing plate to another thus successfully baffling all the heated air
which must pass through the leaf before being allowed to escape from the
apparatus.
"
The danger of "lifting or carrying away small particles of tea is entirely
overcome by the wire mesh of the trays being behind tho leaf and by the four
currents of heated air being drawn by the exhaust fan at the extreme end of
the chambers through four compartments of two or more trays (instead of
through one compartment of eight or more trays) thereby lessening the blast
necessary to overcome the resistance of leaf and trays, and saving valuable vola-
tile constituents, which by the use of present machinery are now being lost,

page_text: The wet leaf is fed into the trays nearest the air heater and so subjected to
the full force of heated air instantly arrests fermentation and being withdrawn
and examined by the attendant and found nearly dry, are then placed at the
end of the chamber nearest the fan where the temperature will be lower on
account of the heated air having previously passed through the fresh or wet
roll. To enable the trays of, leaf to be withdrawn in "still air," I fix louvres at
rach end of each division so that each division of trays can be instantly shut off
from the draft independent of each other, thus enabling the drying to go on
whilst one of the chambers is being emptied of its trays of leaf. I also arrange
a shallow tray under each set of trays to catch the small particles of tea that
fall through termed "dholegoorie." In the automatic type the endless bands
consisting of tilting trays are placed at an angle similar to the above description,
each endless web or band of trays being worked in its own division or chamber
a small aperture is cut in the part near the end of the endless web so as to
allow the leaf to drop through on being discharged from one web to the other,
as it is desirable to finish the drying in a lower temperature. I arrange a louvre
at the end of each division containing the endless webs so that I can admit as
much heated air as is desirable or stop it altogether in either division, and leave
the remaining drying to be accomplished by the heated air radiating from the
chamber itself.
Underneath the endless webs or bands of trays I place small trays to catch, any
particle of leaf that might fall through the perforations of the gills or tilting
trays which comprise the endless web and which small trays can be removed
from the machine by hand at pleasure.
D
L
D1007
FREDERIC PRINCE,
Agent for Applicant.
Improvements in and connected with Machinery for Drying Tea Leaf
in course of Manufacture.
I, NATHAN WILLIAM HORATIO SHARPE, of 16, Lancaster Road, Finsbury Park,
London, 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: - -
This invention refers to apparatus for drying tea leaf or other analogous sub-
stances, and relates to both classes of machines known to the trade as hand tray
and automatic dryers respectively.
In both types as at present in use, the heated air is introduced into the drying
chamber and drawn through the leaf either downwards upwards or at an angle.
In the downward draft type it is found that the current of heated air has neces-
sarily to be strong in order to overcome the resistance of the layers of trays upon
which the leaf rests, this is most detrimental to the quality of the tea large quan-
tities of volatile constituents being lost through the blast pressure.
In the upward draft type where the heated air is taken in at the bottom of the
chambers and pulled upwards through the trays there is a great tendency to
what is known as "lifting "that is, the upward blast carrias with it great
quantities of the finest quality of leaf known as "dholegoorie" and which are
entirely lost, the heated air by being introduced into the drying chamber near
the bottom comes into contact with the partly dried tea afterwards passing to

page_text: the green or fresh roll, this is also detrimental as the partly dried tea should
be finished in a cooler temperature and the fresh roll should have the first blast
of heated air directed against it so as to effectually arrest fermentation which is
most important, and the object of this invention is to overcome the before men-
tioned disadvantages and objections.
I will now describe my invention, by which my object is attained, with
reference to the accompanying drawings, whereon Fig. 1, is a sectional elevation
shewing my hand tray tea drying and final firing machine, and Fig. 2 is a sec-
tional elevation showing an example of my automatic endless web machine.
In a hand tray type of machine such as is shewn at Fig. 1, there is provided
according to my invention a chamber A, say of rectangular form, within which
is located a series of trays B, B, having perforated bottoms, say of wire mesh,
and these trays are arranged at a slight angle, the lower edge being nearest the
air heater C, the latter at Fig. 1, being shewn as consisting of a furnace C, the
products from which heat air tubes C, passing through the apparatus, the air
being heated as it passes through the tubes, which latter deliver into the rec-
tangular chamber A. Thus the leaf placed on the surfaces of the trays is
exposed to the full current of heated air, which latter is drawn through the
chamber A, from the heater C, by exhaust fans D, located at the end of the
chamber A, opposite the heater; to facilitate straight draught and to equally
distribute heated air of an equitable temperature throughout the apparatus, I
divide the rectangular chamber A, horizontally by three or more divisions E, in
each of which the trays B, are placed, at an angle cach reaching from one
dividing plate E, to another thus successfully baffling all the heated air which
must consequently pass through the leaf before being allowed to escape from the
apparatus.
"
The danger of "lifting or carrying away small particles of tea is entirely
overcome by the wire mesh of the trays B, being behind the leaf and by the four
currents of heated air being drawn by the exhaust fan D), at the extreme end of
the chambers A, through four compartments of two or more trays, instead of
through one compartment of eight or more trays, thereby lessening the blast
necessary to overcome the resistance of leaf and trays and saving valuable vola-
tile constituents, which by the use of present machinery are now being lost.
The wet leaf is fed into the trays B, nearest the air heater C, and so being
subjected to the full force of heated air, fermentation is instantly arrested;
upon the tea being withdrawn and examined by the attendant and found nearly
dry, these trays nearest the heater are then placed at the end of the chamber A,
nearest the fan 1), where the temperature will be lower on account of the heated
air having previously passed through the fresh or wet roll; should it be desired
although not so shewn on the drawings, to enable the trays of leaf to be withdrawn
in still air, I in some cases fix louvres or dampers at each end of each division
so that each division of trays can be instantly shut off from the draft independent
of each other thus enabling the drying to go on whilst one of the chambers is
being emptied of its trays of leaf. I also arrange a shallow tray of ordinary
construction not necessary to be specially illustrated in the drawings, under each
set of inclined trays in order to catch the small particles of tea termed
dholegoorie "that fall through. In applying my invention to hand tray appar-
atus and automatic machines, I arrange the parts as is sufficiently illustrated at
Figs. 1 and 2, and referring to the latter figure, B', indicates by the dotted lines
the usual construction of endless bands, consisting of the ordinary tilting trays
and it will be noticed that these bands B, are each arranged at an angle in the
chamber A, they extending from the top of one horizontal partition to the under
side of the next higher one the arrangement being thus similar to that described
with reference to the trays of Fig. 1. The leaf is allowed to drop through and is
carried from one hand to another and gradually descends through the apparatus
as it is desirable to finish the drying at a lower temperature.
ti
As in the example previously described at Fig. 1 I may provide the compart-

page_text: ments or divisions at Fig. 2, with louvres or dampers at the ends of each division
containing the endless webs, although such are not specially shewn in the
drawings, and by the use of such louvres or dampers as much heated air as is
desirable may be admitted in any compartment, or the current may be stopped
altogether and the remaining drying be accomplished by radiation of heat from
the chamber itself.
Underneath the travelling bands B¹, and upon the divisions E, 1 place trays F',
to catch any particle of leaf that might fall through the perforations of the gills
or tilting trays which comprise the endless web and which small trays can be
removed from the machine by hand. The position of the heater C, is indicated
at Fig. 2, the exhaust fan D, being at the opposite end of the machine and by
this arrangement the exhaust air could be blown directly through an aperture
in the factory wall thus keeping the interior of the factory comparatively cool.
It will be gathered from the above description that my horizontal or straight
draught dryer according to my invention, presents characteristic features com-
mon to both the hand tray and the automatic types of machines in that the
moisture is taken direct from each layer of leaf to the fan and discharged with-
but again passing through the tea, and the discharged air is followed up by dry
air from the air heater so that the leaf is continuously subjected to pure hot
air only.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. In machinery or apparatus for drying tea leaf in the course of manufacture,
a dying chamber through which a current of heated air is drawn in a horizontal
direction the said chamber being divided into compartments by horizontal
partitions, together with perforated trays or leaf carriers in the chambers, the
trays or carriers being arranged in inclined position so that the leaf is exposed
to the hot air current the latter passing through the inclined bottoms of the
trays to the exhaust mechanism substantially as described.
2. In machines or apparatus for drying tea leaf in the course of manufacture,
the combination with the arrangement of parts claimed by Claim 1, of horizontal
shallow trays placed on the partitions aforcanid under the inclined trays, to
collect the small particles of tea passing through the trays, substantially as
described.
3. In machinery or apparatus for drying tea leaf in the course of manufacture
as claimed by Claim 1, the combination therewith of movable louvres or dampers
for closing any particular compartment against the air current, substantially as
described.
4. The arrangement and construction of machine or apparatus for drying tea
leaf combined and acting substantially as and for the purposes described with
reference to Fig. 1, of the accompanying drawings.
5. The arrangement and construction of machine or apparatus for drying tea
leaf combined and acting substantially as and for the purposes described with
reference to Fig. 2 of the accompanying drawings.
Dated this 10th day of September 1808
FREDERIC
PRINCE,
37, Cursitor Street, Chancery Lane, London.
Agent for Applicant.