Improvements in Apparatus for Applying Aqueous Vapor or Moist Air or Gases to Substances, especially applicable for Softening, Limping, or Withering Tea Leaf, Moistening or "Ordering." Tobacco Leaf, or for similar treatment of other analogous substances.
Year: 1897

page_text: Date of Application, 23rd June, 1897
Complete Specification Left, 23rd Mar., 1898-Accepted, 18th June, 1898'
PROVISIONAL SPECIFICATION,
Improvements in Apparatus for Applying Aqueous Vapor or Moist
Air or Gases to Substances, especially applicable for Softening,
Limping, or Withering Tea Leaf, Moistening or "Ordering."
Tobacco Leaf, or for similar treatment of other analogous
substances.
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 applying aqueous vapor or moist
air or gases to substances and more especially to apparatus for softening, limping.
or withering tea leaf or other purposes as for example for moistening and softening
or "ordering" tobacco or analogous substances. I will describe the invention more
especially as applied for the purpose of softening, limping or withering tea leaf.
The chief features of the invention are the passing of a current of hot aqueous
vapour or moist warm air or gases for moistening the leaf twice or oftener through
the leaf as this is being carried by a travelling web of foraminous material through a
withering chamber, the current passing alternately downward and upward through
the web; a special construction of the withering chamber whereby the said current
is caused to follow a serpentine course so as to pass through the web downward
and upward alternately and whereby the distribution of the current is approximately
equalized over the whole area of the web; a special arrangement of ducts from the
outlet end of the withering chamber to a fan and from this fan to the inlet end
of the withering chamber; a special arrangement or disposition of steam nozzles
with or without adjoining water nozzles for projecting jets of steam with or
without atomized water into the withering chamber; and the general con-
struction and arrangement of the whole apparatus.
Having stated the chief features of the invention I will now describe an apparatus
in which the invention is embodied.
The body of the apparatus consists of a horizontal box or enclosure (herein
termed the withering chamber) mounted on a suitable stand or legs, and its interior
divided into upper and lower compartments by a travelling web of any suitable
foraminous material such as wire web which is arranged to pass through said
withering chamber from end to end; and about midway between top and bottom.
This web is mounted on a drum at each end and outside of the withering chamber
and its under stretch returns under the bottom and outside of the withering
chamber. The upper and lower compartments of the withering chamber are also
divided into sub-compartments by means of cross partitions so arranged alternately
above and below the web that when a current of air, steam, or vapor is propelled or
drawn from one end of the withering chamber to the other it passes alternately down
and up as a serpentine-like current through the web and in order to equalize the

page_text: distribution of this current over the whole area of the web which is exposed thereto
in each of these sub-compartments formed by the cross partitions, a perforated
and preferably inclined plate is inserted above or below the web as the case may be,
in which plate the total area of the perforations is adjusted so that without throttling
the current unduly, about an equal speed of the current will be passing through
each of the perforations.
mit
To create the main current through the withering chamber I employ a fan
mounted preferably on the top of the withering chamber, and I lead one or more
ducts to the inlet eye or eyes thereof from the last sub-compartment below the
delivery or outgoing end of the web, and I lead another duct from the nozzle of the
fan to the sub-compartment above the inlet or feed end of the web, so that if there
were no openings in the withering chamber the same air would thus circulate con-
tinuously through it and back again through the fan. But as there are openings
for the web and the material thereon to pass through, and as also fresh air is driven
in along with the steam or vapor injected at the feed end of the web, I provide for
the escape of an equivalent volume from the circulating current by having a relief
pipe or chimney-in the pressure duct connecting the nozzle of the fan with the feed
end of the withering chamber.
As it is necessary to use hot aqueous vapor or water spray at the beginning of
the operation of moistening the leaf, I preferably employ jets of steam for this
purpose, and project same (with or without water added thereto from jets directed
into and atomised into fine mist-like spray by the steam jets according to the amount
of moisture that may be necessary to add to the leaf) through a suitable opening
into the sub-compartment of the withering chamber which is above the feed end of
the web, and the force of the steam blowing in through this opening carries with it
a certain amount of fresh atmospheric air, notwithstanding that the circulating
current from the fan is more or less under pressure in this sub-compartment, and
would otherwise have a tendency to blow out through this opening, but the force of
the steam jets being greater than the outward pressure of the circulating current
the steam and its accompanying fresh air therefore rush into the withering chamber.
The web drums may be driven in any suitable manner to give the web the
proper speed of movement, and a revolving brush may be applied to the under side
of the web at the delivery end to brush the web clean of any adhering leaf.
In working the machine the leaf to be moistened or withered is fed on to the web
at the feed end the steam jets are turned on with or without the additional water
jets, and the machine being then in motion the web carries the leaf through the
withering chamber. The circulating current from the pressure duct from the fan
now mixes with the steam and the fresh air driven in therewith, and the mixture
then passes down through the leaf on the web to the sub-compartment below the
web. As its passage along this sub-compartment towards the exhaust ports of
the suction ducts leading to the fan is blocked by the cross partition forming the
further end of the first sub-compartment below the web, (and which is double the
length of the first sub-compartment above) the current now passes upwards through
a perforated plate and through the web and leaf thereon to the first half of the
second upper sub-compartment, then to the second half of this compartment and
through a second perforated plate and through the leaf and web to the second
lower sub-compartment. The current then passes into the suction duct or ducts to
the fan from whence it is again driven into recirculation through the pressure duct
from the fan nozzle minus a portion of the current equal to the amount of fresh
air injected by the steam at the feed end, and also drawn in by the fan suction at
the outlet end of the web, which excess portion of the current escapes through the
relief chimney from the pressure duct.
When tobacco leaf is the substance, under treatment it is sometimes desirable to
provide for extra moistening. For this purpose at the delivery end of the web
and preferably after the leaf has come out of the chamber, I further apply to the
leaf a cold aqueous spray, by jets of air under pressure blowing through jets of
water, so as to atomise the water into a fine mist-like rain, which besides distribut-

page_text: ing this extra moisture perfectly evenly all over the leaf, also cools and prevents it
steaming after it comes out of the machine.
Dated this 23rd day of June 1897.
Improvements in Apparatus for Applying Aqueous Vapor or Moist
Air,or Gases to. Substances, especially applicable, for Softening,
Limping, or Withering Tea Leaf, Moistening or "Ordering"
Tobacco Leaf, or for similar treatment of other analogous
substances.
1
15
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:-
i
This invention has reference to apparatus for applying aqueous vapor or moist
air or gases to substances and more especially to apparatus for softening, limping
or withering tea leaf or for other purposes, as for example for moistening softening
or "ordering" tobacco leaf or analogous substances... I will describe the invention
more especially for the purpose of softening, limping or withering tea leaf.
The chief features of the invention are the passing of a current of hot. aqueous
vapour or moist warin air or gases for moistening the leaf, twice or oftener through
the leaf as this is being carried by a travelling web of foraminous material through
a withering or moistening chamber, the current passing-alternately downward and
upward through the web; a special construction of the withering or moistening
chamber whereby the said current is caused to follow a serpentine course so as to
pass through the web downward and upward alternately and whereby the distribu,
tion of the current is approximately equalised over the whole area of the web; a
special arrangement of ducts from the outlet end of the withering or moistening
chamber to a fan and from this fan to the inlet end of the said chamber; a special
arrangement or disposition of steam nozzles with or without adjoining water, nozzles
for projecting jets of steam with or without atomized water into the withering, or
moistening chamber; and the general construction and arrangement of the whole
apparatus.
Having stated the chief features of the invention I will now describe an apparatus
in which the invention is embodied:
The body of the apparatus consists of a horizontal box or enclosure (herein
termed the withering chamber) mounted on a suitable stand or legs, and its interior
divided into upper and lower compartments by a travelling web of any suitable
foraminous material such as wire web which is arranged to pass through said
withering chamber from end to end; and about, midway between top and bottom.
This web is mounted on a drum at each end and outside of the withering chamber
and its under stretch returns under the bottom and outside of the said chamber.
The upper and lower compartments of the chamber are also divided into sub-com-
partments by means of cross partitions so arranged-alternately above and below the
web that when a current of air, steam, or vapour is propelled or drawn from one end
of the chamber to the other, it passes alternately down and up as a serpentine-like
currents through the: web, and in order to equalise the distribution of this current
over the whole area of the web which is exposed thereto in each of these sub-

page_text: compartments formed by the cross partitions, a perforated and preferably inclined
plate is inserted above or below the web as the case may be, in which plate the total
area of the perforations is adjusted so that without throttling the current unduly,
about an equal speed of the current will be passing through each of the perfora-
tions.
To create the main current through the withering chamber, I employ a fan
mounted preferably on the top of the chamber, and I lead one or more ducts to the
inlet eye or eyes thereof from the last sub-compartment below the delivery or out-
going end of the web, and I lead another duct from the nozzle of the fan to the sub-
compartment above the inlet or feed end of the web, so that if there were no open-
ings in the withering chamber the same air would thus circulate continuously
through it and back again through the fan. But as there are openings for the web
and the material thereon to pass through, and as also fresh air is driven in along
with the steam or vapour injected at the feed end of the web, I provide for the
escape of an equivalent volume from the circulating current by having a relief
pipe or chimney in the pressure duct connecting the nozzle of the fan with the feed
end of the withering chamber.
As it is necessary to use hot aqueous vapour or water spray at the beginning of
the operation of moistening the leaf, I preferably employ jets of steam for this
purpose, and project same (with or without water added thereto from jets directed
into and atomised into fine mistlike spray by the steam jets according to the amount
of moisture that may be necessary to add to the leaf) through a suitable opening
into the sub-compartment of the withering chamber which is above the feed end of
the web, and the force of the steam blowing in through this opening carries with it
a certain amount of fresh atmospheric air, notwithstanding that the circulating
current from the fan is more or less under pressure in this sub-compartment, and
would otherwise have a tendency to blow out through this opening, but the force of
the steam jets being greater than the outward pressure of the circulating current
the steam and its accompanying fresh air therefore rush into the moistening
chamber.
When tobacco leaf is the substance under treatment I further provide for apply-
ing to the leaf at the delivery end of the web and preferably after the leaf has come
out of the withering chamber a cold aqueous spray if more moisture be wanted in
it, by jets of air under pressure blowing through jets of water, so as to atomise the
water into a fine mistlike rain, which besides distributing this extra moisture
perfectly evenly all over the leaf, also cools and prevents it steaming after it comes
out of the machine.
The web drums may be driven in any suitable manner to give the web the
proper speed of movement, and a revolving brush may be applied to the under side
of the web at the delivery end to brush the web clean of any adhering leaf.
In working the machine the leaf to be moistened is fed on to the web at the feed
end, the steam jets are turned on with or without the additional water jets, and the
machine being then in motion the web carries the leaf through the moistening
chamber. The circulating current from the pressure duct from the fun now mixes
'with the steam and the fresh air driven in therewith, and the mixture then passes
down through the leaf on the web to the sub-compartment below. the web. As its
passage along this sub-compartment towards the exhaust.ports of the suction ducts
leading to the fan is blocked by the cross partition forming the further end of the
first sub-compartment below the web (and which is double the length of the
first sub-compartment above) the current now passes upward through' a perforated
plate and through the web and leaf thercon to the first half of the second upper
sub-compartment, then to the second half of this compartment and through a second
perforated plate and through the leaf and web to the second lower sub-compartment.
The current then passes into the suction duct or ducts to the fan from whence it is
again driven into recirculation through the pressure duct from the fan nozzle
minus a portion of the current equal to the amount of fresh air injected by the steam,
at the feed end, and also drawn in by the fan suction at the outlet end of the web,

page_text: which excess portion of the current escapes through the renier chimney from the
pressure duct. If when the leaf (in the case of tobacco leaf) begins delivering out
of the machine it is considered desirable to add a further amount of moisture, the
compressed air jet spray of cold water may then be turned on to it to whatever
extent may be required.
In the accompanying drawings:
Figure 1 is a central longitudinal section but with the fan shown in elevation
of an apparatus constructed in accordance with this invention.
Figure 2 is an elevation of the feed end of the apparatus.
Figure 3 is a plan of the apparatus.
A represents the woven wire endless web carried upon the two revolving
drums B B and supported between same by the rollers C. D is the withering or
moistening chamber through which the upper portion of the wire web A travels,
in the direction indicated by the arrow. The said chamber is divided into upper
and lower compartments by the web A, and these compartiments are further divided
into the sub-compartments D, E, F and G by the cross partitions D' and E'. M and N
are perforated inclined plates in the sub-compartments E and F respectively. H
and H are openings in the ends of the chamber for the entrance and exit respec-
tively, of the wire web. Upon the chamber is mounted the fan I delivering air
into the pressure duct K. The air from this duct passes down through the
perforated plate Linto the upper sub-compartment D, down through the wire web A.
into the lower sub-compartment E and up through the perforated plate M, in the
direction indicated by the arrows into the upper sub-compartment F then down
through the perforated plate N into the lower sub-compartment G and
out through suction ports or openings OO in each side of the sub-compartment G,
and up through the return suction ducts P P to the eyes QQ of the fan I, so that a
constant circuit of air is maintained from the fan through the four sub-compart-
ments of the chamber and back into the fan.
The bearings R of the shaft carrying the drum B at the feed end of the machine
are fitted with adjusting screws so that the web may be kept just sufficiently
tightly strained for satisfactory working.
As the material spread upon the web A enters the upper sub-compartment D by
the entrance port H it is moistened and heated by jets of steam from the pipe $
supplied from any convenient source into which jets of water may be directed in
front of each steam jet to increase its moistening properties, from the water pipe T.
The steam jets atomise the water into mist-like steamy vapour which the force of
the steam jets along with an induced current of fresh air into the upper sub-com-
partment D where it mixes with and is drawn down through the material on the
web A by the circulating current of air from the fan I into the sub-compartment E.
Then up again into the sub-compartment F and thence down again to the sub-
compartment G on reaching which nearly all the moisture and heat of the steamy
vapour will have been absorbed by the material on the web, so that the return
ourrent to the fan has very little moisture left in it. Then the material leaves the
sub-compartment F by the exit port H' and if it still requires more moisture (as it
may do in the case of tobacco leaf) this can be added and the material at same time
cooled by jets of water from the pipe U, these jets being atomised and sprayed upon
the material by jets of compressed air from the pipe V which is supplied by the air
compressor W. X is a rotary brush for removing any material clinging to the wire
web A. X is a truck in position to receive the leaf falling from the web. Y Y are
inspection and cleaning doors. Z is a relief pipe or chimney on the pressure duct H
for the escape of an equivalent volume of air therefrom to that of the fresh air
injected by the steam jets and a further small amount drawn in through the web
exit opening H¹ by the fan suction acting in the sub-compartment G. The relief
pipe 2 is fitted with a sliding valve Z. The web A is driven by means of the
drum B' at the delivery end by any suitable gear-that shown is an arrangement of
worm gearing a b c d operated by the driving pulleys e..

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, I declare that what I
claim ia:
1. In apparatus for applying aqueous vapor or moist air or gases to, substances,
the combination of a withering or moistening chamber, a leaf carrying web
travelling horizontally from end to end of said chamber approximately midway
between the top and bottom of same, openings at opposite ends of said chamber
respectively for the entrance and exit of the web and leaf, partitions alternately
dividing the part of the chamber above said web and the part of the chamber below
said web, and inclined perforated air-distributing plates disposed across the com-
partments formed in said chamber by said partitions, substantially as and for the
purposes set forth.
...
.
2. In apparatus for applying aqueous vapour or moist air or gases to substances,
the combination with a moistening or withering chamber and a leaf carrying web
travelling horizontally from end to end of said chamber approximately midway
between the top and bottom of same, said chamber having at opposite ends openings
respectively for the entrance and exit of the web and leaf, of a fan outside said
chamber, ducts leading respectively from near the outlet end of said chamber to
said fan and from said fan to near the inlet end of said chamber and a relief pipe in
the duct leading from the fan to said chamber, whereby a current of air is
maintained through said chamber and any excess of pressure is relieved, substan-
tially as and for the purposes set forth.
3. In apparatus for applying aqueous vapor or moist air or gases to substances,
the combination of a moistening or withering chamber, a leaf carrying web
travelling horizontally from end to end of said chamber approximately midway
between the top and bottom of same, and said chamber having at opposite ends
openings respectively for the entrance and exit of the web and leaf, partitions
alternately dividing the part of the chamber above said web and the part of the
chamber below said web, a fan creating a current through said chamber, ducts lead-
ing respectively from near the outlet end of said chamber to said fan and from said
fan to near the inlet end of said chamber and a relief pipe in the duct leading from
the fan to said chamber substantially as described whereby the hot aqueous vapor
or moist warm air for moistening the leaf is caused to follow a serpentine course in
said chamber and to pass alternately down and up through the web and leaf at
successive parts of said chamber, and is then drawn off from near the outlet end of
said chamber and forced again into the inlet end of same, while surplus air escapes
through the relief pipe, as and for the purposes set forth.
4. In apparatus for applying aqueous vapor or moist air or gases to substances,
the combination of a moistening or withering chamber, a leaf carrying web
travelling horizontally from end to end of said chamber approximately midway
between the top and bottom of same, and said chamber having at opposite ends
openings respectively for the entrance and exit of the web. and leaf, partitions
alternately dividing the part of the chamber above said web and the part of the
clamber below said web, perforated air-distributing plates disposed across the com-
partments formed in said chamber by said partitions, a fan creating a current
through said chamber, ducts leading respectively from near the outlet end of said
chamber to said fan and from said fan to near.the inlet end of said chamber and a
relief pipe in the duct leading from the fan to said chamber substantially as
described, whereby the hot aqueous vapor or moist warm air for moistening the leaf
is caused to follow a serpentine course in said chamber, is evenly distributed over
the whole area of the web in said compartments is caused to pass alternately down
and up through the web and leaf at successive parts. of said chamber and is then
drawn off from near the outlet end of said chamber and forced again into the inlet
end of same while surplus air escapes through the relief pipe, as and for the purpose
set forth.
5. The combination with the chamber D and the travelling web A, the said
chamber having openings H and H¹ respectively for the entrance and exit of the

page_text: web and the leaf, of steam nozzles outside the said chamber near the opening H,
the said nozzles projecting steam into the said chamber substantially as and for the
purpose set forth.
6. The combination with the chamber D and the travelling web A the said
chamber having openings H and H respectively for the entrance and exit of the
web and the leaf, of steam nozzles outside the said chamber near the opening H
and water nozzles adjoining the said steam nozzles, the steam and water nozzles
projecting steam and atomised water into the said chamber, substantially as and for
the purpose set forth.
7. The general arrangement or combination of parts constituting an improved
apparatus for applying aqueous vapor or moist air or gases to substances, substan-
tially as hereinbefore described and illustrated in the accompanying drawings for
the purposes set forth.
Datu
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.