Improvements in Apparatus for Drying or Partially Drying or other- -wise Treating Tea Leaf, Tobacco Leaf, Coffee, Grain, Malt, Wool, and other substances by a Current of Heated Air.
Year: 1897

page_text: Improvements in Apparatus for Drying or Partially Drying or other-
-wise Treating Tea Leaf, Tobacco Leaf, Coffee, Grain, Malt, Wool,
and other substances by a Current of Heated Air.
I, SAMUEL CLELAND DAVIDSON, of Sirocco Engineering Works, Belfast, Ireland,
Merchant, do hereby declare the nature of this invention to be as follows:-
This invention has reference to apparatus for drying or partially drying or other-
wise treating tea leaf, tobacco leaf, coffee, grain, malt, wool and other substances
by a current of heated air and the invention mainly consists of a special construc-
tion or arrangement of apparatus substantially as hereinafter described whereby
the tea leaf or other substance to be operated on is caused to travel on a web of
foraminous material through a box, chamber or compartment (hereinafter called
the drying chamber) and during its travel through the said chamber is submitted
to the action of an artificial current of air which enters through the top of the dry-
ing chamber (perforated for the purpose) then comes in contact with an air heater
consisting of a range of longitudinal steam pipes, and then passes through the web
and the substance thereon.
In carrying out the invention I form the body of the apparatus of a box chamber
or compartment which I call the drying chamber which may be mounted on a suit-
able stand or legs. Through this chamber a web of any suitable foraminous
material such as wire web, passes horizontally from end to end about midway
between top and bottom and forming the top stretch of an endless web, the under
stretch of which returns under the bottom of and outside the drying chamber.
The web is mounted on a revolving drum at each end and outside of the drying
chamber.
In the upper part of the drying chamber, above the web, is placed an air heater,
consisting of a range of steam pipes extending from end to end of the dry-
ing chamber and suitably mounted and expanded or otherwise secured into a steam
chamber (hereinafter referred to as the steam chest) at each end of the drying
chamber or if the drying chamber is so long that the steam pipes if employed
in single lengths from end to end would be liable to sag one or more intermediate
steam chests may be used so that when live steam from a boiler or exhaust steam
from an engine is admitted to the steam chest at one end of the drying chamber
it will traverse through the whole range of the pipes, and the condensed water
therefrom will be delivered into and drained off from the intermediate or exhaust
end steam chests, from which latter any remaining uncondensed steam escapes.
The range of steam pipes preferably consists of several horizontal rows, the pipes
in each row being in different vertical planes to those of the pipes in the next

page_text: adjoining row or rows so that the air passing down between shall follow a
serpentine or zig zag course.
The top of the drying chamber, which is constructed directly over the steam
pipes, consists of a series of perforated plates for the admission of air, the per-
forations being preferably so arranged that the air passing through same immedi-
ately strikes against the nearest steam pipe thereto and is deflected therefrom over
and amongst the other steam pipes, so that the air is thus brought into efficient
contact therewith and becomes-equivalently heated thereby.
The drying chamber below the web is connected to a fan or other air exhausting
appliance so that a current of air may be drawn down through the perforated
plates and steam pipes and through the material on the web.
The fan may be fitted with an engine which may also drive the web drums and
the exhaust steam from which may be used in the steam pipes of the drying box.
The web drums may be driven by any suitable means that would give the web
the proper speed of travel and a revolving brush applied to the under side of the
web serves to brush the web clear of any adhering. leaf.
In working the machine the material is spread on the web, preferably at the
Bame end of the machine as the steam is admitted to the heater, so that the machine
being in motion the wet or moist material' immediately on entering the drying
chamber comes in contact with the hottest part of the air current passing down
through same.
Dated 1st day of June 1991.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.
Improvements in Apparatus for Drying or Partially Drying or other-
wise Treating Tea Leaf, Tobacco Leaf, Coffee, Grain, Malt, Wool,
and other substances by a Current of Heated Air.
I, SAMUEL CLELAND DAVIDSON, of Sirocco Engineering Works, Belfast, Ireland,
Merchant, 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 has reference to apparatus for drying or partially drying or other-
wise treating tea leaf, tobacco leaf, coffee, grain, malt, wool. and other substances
by a current of heated air and the invention mainly consists of a special construc-
tion or arrangement of apparatus substantially as hereinafter described whereby
the tea leaf or other substance to be operated on is caused to travel' on a web of
foraminous material through a box, chamber or compartment (hereinafter called
the drying chamber) and during its travel through the said chamber is submitted
to the action of an artificial current of air which enters through the top of the dry-
ing chamber (perforated for the purpose) then comes in contact with an air heater
consisting of a range of longitudinal steam pipes, and then passes through the web
and the substance thereon.
In the accompanying drawings:-
7
Figure 1 is a central longitudinal section of an apparatus constructed according
to my invention.
Figure 2 is a cross section on the line 2-2 of Figures 1 and 3.

page_text: 1
1
1
guit
which I call the drying chamber and which may be mounted as shown on a
able stand or legs; through this chamber A a web B of any suitable foraminous
material, such as wire web' passes horizontally from end to end about midway
between top and bottom and forming the top stretch of an endless web the under
stretch of which returns as shown under the bottom of and outside the drying
chamber A. The web B is mounted on two revolving drums C C arranged
respectively outside of the drying chamber A at the inlet and delivery ends
respectively of the apparatus, and is supported between the same by rollers D.
The hearings E E of the shaft carrying the drum Cat the feed end of the appar
atus are fitted with adjusting screws F, so that the web may be kept sufficiently
strained for satisfactory working. Openings or ports GG are formed in the ends
of the drying chamber A for the entrance and exit respectively of 'the wire web B.
In the upper part of the drying chamber A above the web B is placed an air
heater "H, consisting of a range of steam pipes extending from end to end of the
drying chamber, and suitably mounted and expanded or otherwise secured into
steam chambers J Ja (hereinafter referred to as the steam chests) arranged res-
pectively at the inlet and delivery ends of the drying chamber A or if the drying
chamber A is so long that the steam pipes if employed in single lengths from end
to end would be liable to sag, one or more intermediate steam chests such as J¹
may be used-so that when live steam from a boiler or exhaust steam from an
engine is admitted to the steam chest at one end of the drying chamber it will
traverse through the whole range of the pipes, and the condensed water therefore
will be delivered into and drained off from the intermediate or exhaust end steam
chests, from which latter any remaining uncondensed steam escapes. The range of
steam pipes preferably consists as shown of several horizontal rows, the pipes in
each row being in different vertical planes to those of the pipes in the next adjoin-
ing row or rows so that the air passing down between shall follow a serpentine or
zig-zag course.
The top of the drying chamber, which is constructed directly over the steam
pipes, consists of a series of perforated plates K for the admission of air, the per-
forations being preferably so arranged that the air passing through same
immediately strikes against the nearest steam pipe thereto and is deflected there-
from over and amongst the other steam pipes, so that the air is thus brought into
efficient contact therewith and becomes equivalently heated thereby.
Exhaust openings or ports L are provided in the lower portion of the drying
chamber A below the web; they lead to an air duct M through which the air passes
to a fan or other air exhausting appliance N so that a current of air may be drawn
down through the perforated plates K and steam pipes H and through the material
on the web B.
The fan N may be fitted with an engine which may also drive one of the web
drums C C¹ at the proper speed of travel and the exhaust steam from which may
be led through the pipe S to the steam pipes II of the drying chamber. In the
drawings the engine is shown as driving the drum C by means of the belt a and
the worm gearing b c d e.
A revolving brush R applied to the underside of the web B at the delivery end
of the machine serves to brush the web clear of any adhering leaf.
In working the machine the material is spread on the web B preferably at the
same end of the machine as the steam is admitted to the heater H, so that
the machine being in motion the wet or moist material immediately on entering the
drying chamber A. comes in contact with the hottest part of the air current.passing
down through same.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
In apparatus for drying or partially drying or otherwise treating

page_text: the combination of a drying or treating chamber, a travelling web
of foraminous material carrying the substance to be treated in a hori-
zontal direction through the said chamber, a perforated top to said chamber
for the inlet of air, range of steam pipes below said perforated top, heating the
incoming air before it comes in contact with the substance on the web, and a fan
or exhaust apparatus in communication with the chamber below the web and
drawing the heated air through the web and the substance thereon, substantially
as hereinbefore described.
Dated th: 09-1
Mah 1000
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.