Improvements in Tea-drying Machinery and Stoves or Air-heating Apparatus therefor.
Year: 1890

page_text: Date of Application, 18th Apr., 1890-Accepted, 31st May, 1890
COMPLETE SPECIFICATION.
Improvements in Tea-drying Machinery and Stoves or Air-heating
Apparatus therefor.
I, HENRY THOMPSON of Ipswich, in the county of Suffolk, 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 certain improvements connected with tea drying
machinery, and stoves or air heating apparatus therefor.
The object of my said invention being to provide an efficient drier which can be
operated by hand or power as preferred, to facilitate and regulate the feeding and
discharging of the leaf to be dried, such being preferably both fed to and delivered
outside the drying chamber, also to prevent waste of the small tea (dropping below
the trays) through burning; and further to provide improved heating apparatus for
such drier.
And my said improvements consist in an improved arrangement of drier in combi-
nation with improved heating apparatus therefor which may consist either of a
tubular construction of stove or a double plated stove, (the fire of which may be at
the side or underneath,) both such as hereinafter set forth, and above which heating
apparatus the drier is placed. And further, in certain improvements connected with
the endless bands or chains and the perforated and tilting trays carried thereon for
transmitting and precipitating the leaf whilst being dried (such as are shown and
described in my Specification No. 8327 of 1888 ;) and in the exhausting (by the
employment of two or more fans) of the hot air from the drying chamber so as to
obtain complete and uniform radiation of the air.

page_text: .
Specification No. 8327 of 1888) are carried by a new construction of endless band or
chain B, such construction consisting in the pivots of the links J being tubular
rivets K, the pivots L of the said trays are carried within the rivets K, by which
means the trays are extended up to the edge of the chain B thereby giving more
drying space and preventing the hot air from passing through the drying chamber
without being fully utilized. The said trays Care formed with the rim or T edge
bent and doubled up out of one piece of metal so as to make such stronger (see Fig. 5,
and the detail view thereof,) the other may also be similarly doubled up forming
a bead.
To prevent the small tea or leaf (which drops through the perforations of the trays
to the bottom of the drying chamber) being burnt, inclines, plates or guides K¹ are
provided (see Fig. 6,) to carry the leaf forwards away from the furnace and below the
entrance for the hot air, doors being provided for allowing the small tea or leaf to
be taken out as it accumulates. When the machine or drier is operated by hand
the usual or ordinary mechanism or lever arrangement is employed, when operated by
power it is driven as follows:-
I drive direct off the fan shaft M. to a pulley N fixed to a cone or stack of pulleys O
loose upon one of the chain wheel shafts P power being transmitted to a second cone
or stack or pulleys R upon a shaft S having a bevel wheel S¹ gearing with a second
bevel wheel S2 upon a vertical shaft S³ provided with a series of worms S' gearing
with worm wheels S upon each of the chain wheel shafts.
The improved heating apparatus consists of a fire brick furnace T with arched top T¹
in close proximity to this furnace (see Fig. 6,) are a series of double plates U made
preferably in two pieces with flanges U₁ for bolting them together and formed with
face pieces Uso that there are cold air chambers or passages V between each double
plate and flues W for the smoke and heated gases between each air chamber. The
heated gases from the furnace pass out to the said plates then into the spaces between
each air chamber then upwards and downwards (see direction of arrows) and so on to
any number or extent required thus heating the air upon its upward course between
each plate by the heated gases radiating around it passing away (when their heat has
been thoroughly utilized) to the chimney or shaft above the furnace. The faces U³
are formed upon the said plates so that when bolted together the required space is
left between them at their outsides for the air to be heated on its way to the drying
chamber between each set of plates at the insides for the heated gases. Suitable soot
doors Ware provided in suitable positions. Should any of the double plates require
renewal or repairing such can be easily attended to without interfering or disturbing
the rest of the apparatus.
Or the heating apparatus may be constructed as shown in Figs. 1, 2 and 3, and
consist of two series of tubes X having an air chamber Y between them, the cold air
to be heated is admitted at each outer end of the tubes X and passes along to the 'air
chamber Y and then upwards to the drying chamber D.
The heated gases from the furnace pass around the 'air chamber Y on each side 'on
their way to the chimney Z.
The dotted arrows indicate the passage of the cold 'and 'hot 'airs, and the 'full'arrows
the passage of the smoke and heated gases.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In tea drying machinery or apparatus placing the chain wheels of the feed
outside the drying chamber in covers in the manner and for the purposes shown and
described.
2. The use and employment of a tubular furnace for tea drying in which the air is
admitted at one end of the tubes and passes forwards to a 'central air chamber for the
purposes shown and described.
3. The use and employment. of a furnace for tea drying consisting of a series of
double plates forming radiating chambers for the smoke and heated gases and air

page_text: chambers between them for radiating and thoroughly utilizing the heated air in the
manner and for the purposes shown and described.
4. The use and employment of endless bands the pivots of the links of which
are tubular rivets for carrying the pivots of the trays such as shown and
described.
1
1
1 1000
Pasca
p
JOHN E. WALSH,
Royal Exchange Chambers, Boar Lane, Leeds, Agent for the Applicant.