Improvements in Processes and Apparatus for the Preparation of an Extract of Tea, and in the Utilisation of the Bye-products.
Year: 1889

page_text: Date of Application, 16th Dec., 1889
Complete Specification Left, 16th Sept., 1890-Accepted, 18th Oct., 1890
PROTIVNAL DILCIFICATION.
Improvements in Processes and Apparatus for the Preparation of an
Extract of Tea, and in the Utilisation of the Bye-products.
I, EDWARD SONSTADT, of Churchfields, Cheshunt, Herts, Fellow of the Chemical
Society, do hereby declare the nature of this invention to be as follows:-
The tea to be extracted is placed in a vessel or digester, preferably of conical form,
widest at top, furnished with a movable perforated false-bottom, communicating by a
tube, acting as a syphon tube, with another vessel used as a boiler. The syphon tube
opens at one end into the space below the false-bottom, and may pass through the side
of the digester, to be bent successively upwards and downwards, or it may be taken
through the cover of the digester, in either case to enter the cover of the boiler, so
that when water is boiled in the latter, the steam may pass into the digester.
The
tea infusion formed in the digester by the water there condensed, passes by suction
into the boiler through the syphon tube when the boiling is checked.
The syphon
tube may be furnished with a perforated cap at the open end within the digester. The
boiler, which is preferably placed on a lower level than the digester, and is intended
to receive part of the water to be used in making the tea infusion, may conveniently
have the form of an upright short cylinder; it is supplied with a cover, or manhole
with cover, secured steam-tight, through which the syphon tube enters. The syphon
tube may be jointed with a ball and socket joint between the boiler and digester, to
allow of some play of movement. The boiler is furnished with a water-gauge, exit
cock near the bottom, and small opening for a thermometer, or it may have a pressure-
gauge. A supplementary boiler or feeder is also provided, on a higher level than the
digester, a valved tube from the bottom of which boiler enters the side of the digester
near the top, and is furnished with a spreader, so as to spray the hot water over the
surface of the tea. The supplementary boiler may be similar in size and form to the
first-named boiler, and is also supplied with a water-gauge and opening for a thermo-
meter, besides which an upright tube open to the air, with cock, is set in the steam-
tight cover. When it is desired to run hot water into the digester, the water in the
supplementary boiler is heated to boiling, the cock in the upright tube is closed, and
when sufficient pressure is attained, the cock in the horizontal tube leading into the
digester is opened, and boiling hot water is sprayed in through the spreader. The
digester is preferably provided with a rod, sliding up and down through a stuffing-
box in the cover, furnished at bottom with arms for pushing down the swollen tea-
leaves, and for compressing them when the infusion is sucked back into the boiler..
The rod can not only be pushed or drawn down or up, but may be turned, so that the
arms may be made to reach every part. The arms may be provided with spines or
spikes on their under sides, for perforating the tea-leaves, should they become too
close to admit free passage for steam. The cover of the digester is provided with an
aperture to receive an upright condensing or cohobating tube, with its adjuncts for
collecting the tea-aroma, to be described in the following paragraph. The digester
and two boilers and connecting tubes are preferably made of nickel, or of copper,
nickel-plated within, and the nickel surfaces in the digester and boiler may, if desired,
be further coated with silver.
The upright tube for insertion through the cover of the digester may be provided
with a series of small chambers or bulbs, connected to the main tube by small tubes in
the manner well known as adopted in laboratory fractional distillations; or it may be
plain, in which case it should be of greater height. The tube may be cooled externally,
if desired, by a water-jacket or otherwise. The opening at the top is closed by a cork
or cock. Near the top a sloping side tube enters, communicating with one or more
mall vessels for condensing the small proportion of steam carrying aroma, and
LD
071

page_text: forming when condensed aroma-water, permitted to reach so far. These condensing
vessels are connected by tubing to one or more narrow closed cylinders (but with a
small outlet to the air at the end cylinder) charged with wool, preferably fleece wool
of fine quality, which absorbs and retains the uncondensed aroma. I prefer that such
wool should be spun into yarn, and knitted or woven into pieces of convenient shape
and size. The upright tube and attached condensing apparatus for the aroma-water
and aroma, may be of glass, earthenware, or other suitable material.
To work the apparatus, after adjustment of the movable false-bottom and syphon
tube and closure of the cover, to which the syphon tube is attached, tea is introduced
through the aperture in the digester for admitting the upright tube, the latter is fixed
in position, and water that has been heated in the subsidiary boiler is run in, the cock
being closed when a suitable proportion has been admitted. Water that has been
heated in the boiler connected to the syphon tube is then brought to boiling heat, and
steam passes into the digester through the tube into the space below the false-bottom,
rising through which it boils the water or infusion in the digester. The rate of
boiling is so regulated, that only a very small proportion of steam is allowed to pass
into the vessel or vessels for condensing aroma-water. I usually find it advisable to
take off altogether less than one per cent. of the total water employed in obtaining the
tea infusion. The better to control the issue of steam, and at the same time to
permit of rapid distillation of water from the boiler into the digester, I prefer to
provide a water-jacket for a part of the digester, which can be supplied with cold or
hot water, or disused, according to requirements. When the tea has thus been treated
with a convenient proportion of boiling water for a short time, the flame is lowered
or shut off from the boiler, when immediately on the water ceasing to boil, the
infusion is sucked back, and flows into the boiler, the top of the upright tube being
simultaneously opened to admit air, without drawing air through the wool. The
boiling may then be recommenced, a little boiling water is run in from the subsidiary
boiler to wash the tea, and the washings are sucked out by again ceasing to boil in
the main boiler. Steam is then again passed in to condense in the digester, with or
without further additions of water from the subsidiary, boiler, and the process is con-
tinued for as long, and with as many repetitions of successive sucking back into the
boiler, as may be necessary to sufficiently extract the tea, the strong infusion of which
is then entirely in the boiler. Meanwhile aroma-water and aroma are continuously
collected as described, and there is practically no escape or loss of aroma throughout
the process. It will be understood that, except while sucking back, the top opening
to the air of the condensing tube is kept closed. I find that by this treatment, one
part of tea can be effectively extracted by about ten or twelve parts of water, the
water being divided between the two boilers on starting work. A small proportion
of tea charcoal may be added to the tea treated in the digester, or may be placed in
the boiler, with advantage to the infusion in the case of certain kinds of tea.
When the charge of tea is sufficiently extracted, the hot infusion is run from the
boiler into an evaporating dish, which may be heated by a steam-jacket or otherwise.
The dish has a rim or flange to receive a Lood shaped like an inverted funnel, and a
trough or channel with outlet cock, under the hood, is provided to receive the water
condensed on the inner sides of the hood. A tube is taken from near the top of the
latter to a condenser. A rod carrying an arm with projecting prongs or wires is
made to slide through a plug or cork closing the top of the hood, which can be
manipulated so as to break up the film which forms on the surface of the infusion
during evaporation. The water condensed from the steam given off carries some
aroma, and is used in infusing the next charge of tea. A little sugar may be added
to the infusion before or during concentration. Any convenient number of evaporating
dishes may be used; they are preferably made of copper, nickel-plated, and the nickel
surface may be further coated with silver.
The concentrated tea infusion is run out or removed while hot into a mixer, con-
sisting of a stout or massive cylindrical vessel, with flat bottom, and cover capable of
being secured on steam-tight, having a stuffing box through which a rod, carrying
arms or beaters, can be freely moved up and down, and turned about The mixer is

page_text: preferably cast in brass or gun-metal, and nickel-plated; it may be also plated with
silver internally over the nickel. A valved or plugged outlet is provided at or near
the bottom. The cover has fitted into it a small valved tube to carry off steam to a
condenser. The vessel, owing to its thickness, may be heated by a flame below,
without danger, if proper care is used, of overheating the contents. The final con-
centration may be conducted with or without adaptation of the cover, but when the
cover is adapted, the steam arising may be condensed, and the weak aroma-water
added to that obtained during the first stage of the evaporation. The liquid is
preferably so far concentrated in the mixer, that a sample taken from it may harden
on cooling. During concentration the liquid should be agitated, by action of the
mechanical agitator if the cover is on, or otherwise if it is off.
Part of the wool, aromatised in the apparatus connected to 'the digester, as already
described, is stored in a close vessel with lump sugar, which abstracts some of the
aroma. The rest of the wool is placed in a mixer like that already described, with
sugar moistened with water or aroma-water. The cover is fitted on, all apertures
closed, and heat is applied until a temperature not much below or above 100° C. is
reached, By means of the beaters attached to the movable rod working through the
cover, the liquefied or dissolved sugar is well incorporated with the wool, from which
it takes up aroma. The wool may be expressed in the mixer by introducing a per-
forated platen, and forcing it downwards by suitable means in the closed heated vessel.
But I prefer to transfer the wool, cooled partially but yet plastic, to be laid out
smooth between platens in a suitably constructed closed press, that can be suf-
ficiently heated by a steam-jacket or otherwise. The aromatised sugar can then, by
proper compression while hot, be expressed from the wool and received in suitable
receptacles not fully exposed to the air. The pressed wool may then be again
heated up in the mixer with fresh moistened sugar, and be again pressed, and so on,
until sufficiently exhausted. The wool may then be washed, dried, and reused.
The process is throughout so conducted as to avoid serious loss of the volatile
aroma. The sugar thus strongly aromatised is stored in air-tight vessels until
required for use.
The small quantity of strong aroma-water collected in the apparatus attached to
the digester, as described, is used to moisten lumps of sugar, which when thus
wetted are placed in the mixer containing the more or less dried tea infusion or
extract. The sugar aromatised by heating with the aromatised wool, or part of it,
is also placed in the mixer, together with as much of the dry lumps of sugar
stored with the aromatised wool, already mentioned, as may be needed to give a
product which, when cold, will be sufficiently dry. The cover is then secured on,
all apertures are closed, and heat is gently applied, until, (as may be judged of
by moistening the outside of the vessel in spots from time to time), a proper
temperature, say of about 100° C., is reached. The mechanical agitator is worked
until it moves smoothly without resistance, and the whole contents of the mixer are
thoroughly incorporated. The vessel may then, after partial cooling, be opened,
and the vet warm and plastic extract may be removed, to be rolled and cut up to
convenient shapes, or otherwise moulded, by known processes. Or the vessel may
while yet hot be emptied by opening the valve or cock in the bottom outlet, and
allowing the liquid or semi-liquid extract to flow out on to a cold plate, protected
from free access of air if necessary, and the extract might then be rolled and cut up
or otherwise dealt with as desired. The process may be modified in various ways, as
for instance, the aromatised wool may be worked up with the tea extract and the wet
and dry aromatised sugar, instead of first exhausting the wool of its aroma by heating
it with moistened sugar only. The highly aromatised tea extract with sugar,
obtained as described, and moulded into shapes convenient for packing or for use,
should be preserved in air-tight vessels. On treating a suitable portion of the extract
thus made and preserved, with boiling water, a refreshing" cup of tea" is obtained.
To produce a liquid extract, the solid extract is dissolved in the least possible quantity
of water, when it may be bottled up and fitted for preservation by any of the known

page_text: processes for preserving such liquids.
in a solid state.
Sugar charged with tea-aroma may be made into confectionary by any usual
process, permitting preservation of the aroma. Any excess of tea-aroma collected
by the wool in the described process over requirements in making the tea-extract,
can thus be utilised as a bye-product in making a tea confection, that is, a confection
possessing the aroma without the other tea constituents.
But I prefer to issue the extract to the public
The spent tea leaves from the charge worked off in the digester are compressed
and made into convenient blocks, to be disposed of as manure, for which purpose,
being highly nitrogenous, they are suitable; or the pressed tea leaves are dried, and
carbonised in a close retort, to obtain tea charcoal, (part of which may be applied
as already described), and an ammoniacal water and tea-tar, from which ammonia,
other nitrogen compounds, acetic acid, and other products, are obtainable.
tea-tar contains a white crystalline substance, of remarkably high melting point,
obtainable by sublimation from the pitch or tailings resulting when the tea-tar is
distilled. This substance I have as yet obtained in quantities insufficient for
satifactory investigation.
Tatod i 1441 3. T 1
1000
The
COMILMIL DICITICATION.
Improvements in Processes and Apparatus for the Preparation of an
Extract of Tea, and in the Utilisation of the Bye-products.
I, EDWARD SONSTADT, of Churchfields, Cheshunt, Herts, Fellow of the Chemical
Society, 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:-
The tea to be extracted is placed in a vessel or digester, preferably of conical form,
widest at top, furnished with a movable perforated false-bottom, communicating by a
tube, acting as a syphon tube, with another vessel used as a boiler. The syphon tube
opens at one end into the space below the false-bottom, and may pass through the side
of the digester, to be bent successively upwards and downwards; or it may be taken
through the cover of the digester, in either case to enter the cover of the boiler, so
that when water is boiled in the latter, the steam may pass into the digester. The tea
infusion formed in the digester by the water there condensed, passes by suction into
the boiler through the syphon tube when the boiling is checked. The syphon tube
may be furnished with a perforated cap at the open end within the digester. The
boiler, which is preferably placed on a lower level than the digester, and is intended
to receive part of the water to he used in making the tea infusion, may conveniently
have the form of an upright short cylinder; it is supplied with a cover, or manhole
with cover, secured steam-tight, through which the syphon tube enters. The syphon
tube may be jointed with a ball and socket joint between the boiler and digester, to
allow of some play of movement. The boiler is furnished with a water-gauge, exit
cock near the bottom, and small opening for a thermometer, or it may have a
pressure-gauge. A supplementary boiler or feeder is also provided, on a higher level
than the digester, a valved tube from near the bottom of which boiler, enters the side
of the digester near the top, and is furnished with a spreader, so as to spray the hot
water over the surface of the tea. The supplementary boiler may be similar in size
and form to the first-named boiler, and is also supplied with a water-gauge and
opening for a thermometer, besides which an upright tube open to the air, with cock,
is set in the steam-tight cover. When it is desired to run hot water into the digester,
the water in the supplementary boiler is heated to boiling, the cock in the upright
tube is closed, and when sufficient pressure is attained, the cock in the horizontal tube
leading to the digester is opened, and boiling hot water is sprayed in through the
spreader. The digester is preferably provided with a rod sliding up and down

page_text: through a stuffing-box in the cover, furnished at bottom with arms for pushing down
the swollen tea-leaves, and for compressing them when the infusion is sucked back
into the boiler. The rod can not only be pushed or drawn down or up, but may be
turned, so that the arms may be made to reach every part. The arms may be provided
with spines or spikes on their under sides, for perforating the tea-leaves, should they
become too close to admit free passage for steam. The cover of the digester is
provided with an aperture to receive an upright condensing or cohobating tube, with
its adjuncts for collecting the tea-aroma, to be described in the following paragraph.
The digester and two boilers and connecting tubes are preferably made of nickel, or
of copper, nickel-plated within, and the nickel surfaces in the digester and boiler may,
if desired, be further coated with silver. Or copper, brass, or other suitable metal or
alloy, silver-plated on the inner surfaces, may be used.
The upright tube for insertion through the cover of the digester may be provided
with a series of small chambers or bulbs, connected to the main tube by small tubes
in the manner well known as adopted in laboratory fractional distillations; or it may
be plain, in which case it should be of greater height. The tube may be cooled
externally, if desired, by a water-jacket or otherwise. The opening at the top is
closed by a cork or cock. Near the top a sloping side tube enters, communicating
with one or more small vessels for condensing the small proportion of steam carrying
aroma, and forming when condensed aroma-water, permitted to reach so far. These
condensing vessels are connected by tubing to one or more narrow closed cylinders
(but with a small outlet to the air at the end cylinder) charged with wool, preferably
fleece wool of fine quality, which absorbs and retains the uncondensed aroma.
vessels are preferably cooled by ice. I prefer that the wool should be spun into yarn,
and knitted or woven into pieces of convenient shape and size. But wool may be
replaced by other suitable absorptive material. The upright tube and attached con-
densing apparatus for the aroma-water and aroma, may be of glass, earthenware, or
other suitable material.
These
To work the apparatus, after adjustment of the movable false-bottom and syphon
tube and closure of the cover, to which the syphon tube is attached, tea is introduced
through the aperture in the digester for admitting the upright tube, the latter is fixed
in position, and water that has been heated in the subsidiary boiler is run in, the cock
being closed when a suitable proportion has been admitted. Water that has been
previously heated in the boiler connected to the syphon tube is then brought to a boil,
and steam passes into the digester through the tube into the space below the false-
bottom, and heats or boils the water or infusion in the digester. The rate of boiling
is so regulated, that only a very small proportion of steam is allowed to pass into the
vessel or vessels for condensing aroma-water. It is not absolutely necessary that any
steam should pass for condensation; but if it does so, I prefer to take off altogether
as aroma-water less than one per cent. of the total water employed in obtaining the
tea-infusion. The better to control the issue of steam, and at the same time to permit
of rapid distillation of water from the boiler into the digester, I prefer to provide a
water-jacket for a part of the digester, which can be supplied with cold or hot water,
or disused, according to requirements. When the tea has thus been treated with a
convenient proportion of boiling water for a short time, the flame is lowered or shut
off from the boiler, when immediately on the water ceasing to boil, the infusion is
sucked back and flows into the boiler, the top of the upright tube being simultaneously
opened to admit air, to avoid drawing air through the wool. The boiler may be
externally cooled in any convenient way, while the suction is going on. The boiling
may then be recommenced, a little boiling water is run into the digester from the
subsidiary boiler to wash the tea, and the washings are sucked out by again ceasing
to boil in the main boiler. Steam is then again passed in to condense in the
digester, with or without further addition of water from the subsidiary boiler, and the
process is continued for as long, and with as many repetitions of successive sucking
back into the boiler, as may be necessary to sufficiently extract the tea, the strong
infusion of which is then entirely in the boiler. The boiler may be externally cooled
in any convenient way, while the suction is going on. Meanwhile aroma-water and

page_text: aroma, or aroma only, as the case may be, are continuously collected as described, and
there is practically no escape or loss of aroma throughout the process. It will be
understood that, except while sucking back, the top opening to the air of the con-
densing tube is kept closed. I find that by this treatment, one part of tea can be
effectively extracted by about ten or twelve parts of water, the water being divided
between the two boilers on starting work.
When the charge of tea is sufficiently extracted, the hot infusion is run from the
boiler into an evaporating dish, which may be heated by a steam-jacket or otherwise.
The dish has a rim or flange to receive a hood shaped like an inverted funnel, and a
trough or channel, with outlet cock, is provided under the hood, to receive the water
'condensed on the inner sides of the hood, which may be fitted with a water-jacket. A
tube is taken from near the top of the hood to a condenser. A rod carrying an arm
with projecting prongs or wires is made to slide through a plug or cork closing the
top of the hood, which can be manipulated so as to break up the film which forms on
the surface of the infusion during evaporation. The water condensed from the steam
given off carries some aroma, and is used in infusing the next charge of tea. A little
sugar may be added to the infusion before or during concentration. Any convenient
number of evaporating dishes may be used; they are preferably made of copper,
nickel or silver-plated, or silver-plated on a nickel surface.
The concentrated tea-infusion is run out or removed while hot from the evaporator
into a mixer, consisting of a stout or massive cylindrical vessel, with flat bottom, or
of any convenient shape, with a cover capable of being secured on steam-tight,
having a stuffing-box through which a rod, carrying arms or beaters, can be freely
moved up and down, and turned about. The mixer is preferably cast in brass or gun-
metal, and nickel-plated; it may be also plated with silver internally over the nickel;
or the brass or gun-metal may be silver-plated internally. A valved or plugged outlet
may be provided at or near the bottom. The mixer may have fitted into it a small
valved tube to carry off steam to a condenser. The vessel, owing to its thickness,
may be heated by a flame below, without danger, if proper care is used, of over-
heating the contents. The final concentration may be conducted with or without
adaptation of the cover, but when the cover is adapted, the steam passing through a
valved outlet may be condensed, and the weak aroma-water added to that obtained
during the first stage of the evaporation. The liquid is preferably so far concentrated
in the mixer, that a sample taken from it may harden on cooling. During concen-
tration the liquid should be agitated, by action of the mechanical agitator if the cover
is on, or otherwise if it is off.
Part of the wool, aromatised in the apparatus connected to the digester, as already
described. is stored in a close vessel with lump sugar, which abstracts some of the
aroma. The rest of the wool is placed in a mixer like that already described, with
sugar moistened with water or aroma-water. The cover is fitted on, all apertures
closed, and heat is applied until a temperature not much below or above 100° C. is
reached. By means of the beaters attached to the movable rod working through the
cover, the liquefied or dissolved sugar is well incorporated with the wool, from which
it takes up aroma. The wool may be expressed in the mixer by introducing a per-
forated platen, and forcing it downwards by suitable means in the close heated vessel.
But I prefer to transfer the wool, cooled partially but yet plastic, to be laid out
smooth between platens in a suitably constructed closed press, that can be sufficiently
heated by a steam-jacket or otherwise. The aromatised sugar can then, by proper
compression while hot. be expressed from the wool and received in suitable receptacles
not fully exposed to the air. The pressed wool may then be again heated up in the
mixer with fresh moistened sugar, and be again pressed, and so on, until sufficiently
exhausted. The wool may then be washed, dried, and reused.
The process is
throughout so conducted as to avoid serious loss of the volatile aroma. The sugar thus
strongly aromatised is stored in air-tight vessels until required for use.
The small quantity of strong aroma-water collected in the apparatus attached to the
digester, as described, is used to moisten lumps of sugar, which when thus wetted are
placed in the mixer containing the more or less dried tea infusion or extract.. In case

page_text: no aroma-water has been collected, the sugar may be moistened with water.
The
sugar aromatised by heating with the aromatised wool, or part of it, is also placed in
the mixer, together with as much of the dry lumps of sugar stored with the aromatised
wool, already mentioned, as may be needed to give a product which, when cold, will
be sufficiently dry. The cover is then secured on, all apertures are closed, and heat
gently applied, until, (as may be judged of by moistening the outside of the vessel in
spots from time to time), a proper temperature, say of about 100° C., is reached. The
mechanical agitator is worked, until it moves smoothly without resistance, and the
whole contents of the mixer are thoroughly incorporated. The vessel may then, after
partial cooling, be opened, and the yet warm and plastic mass may be removed, to be'
rolled and cut up to convenient shapes, or otherwise moulded, by known processes.
Or the vessel may while yet hot be emptied by opening the valve or cock in the bottom
outlet, and allowing the liquid or semi-liquid extract to flow out on to a cold plate,
protected from free access of air if necessary, and the extract might then be rolled
and cut up or otherwise dealt with as desired. The process may be modified in
various ways; as for instance, the aromatised wool may be worked up with the tea-
extract and the wet and dry aromatised sugar, instead of first exhausting the wool of
its aroma by heating it with moistened sugar only, and then separating the wool by
pressure while hot as in the former case. The highly aromatised tea-extract with
sugar, obtained as described, and moulded into shapes convenient for packing or for
use, should be preserved in air-tight vessels. On treating a suitable portion of the
extract thus made and preserved with hot water, a refreshing "cup of tea" is obtained.
To produce a liquid extract, the solid extract is dissolved in the least possible quantity
of hot water, when it may be bottled up and fitted for preservation by any of the
known processes for preserving such liquids. But I prefer to issue the extract to the
public in the solid state.
Sugar charged with tea-aroma may be made into a confection by any usual process
permitting preservation of the aroma. Any excess of tea-aroma collected by the wool
in the described process over requirements in making the tea-extract, can thus be
utilised as a bye-product in making a tea-confection; that is, a confection possessing
the aroma without the other tea constituents.
The spent tea-leaves from the charge worked off in the digester are compressed and
made into convenient blocks to be disposed of as manure, for which purpose, being
highly nitrogenous, they are suitable; or the pressed tea-leaves are dried, and car-
bonised in a close retort, to obtain tea-charcoal, and an ammoniacal water and tea-tar,
from which ammonia, other nitrogen compounds, acetic acid, and other products are
obtainable.
In the sheet of explanatory drawings appended hereto, Fig. 1. represents in vertical
section, the digester, boiler, supplementary boiler, cohobating tube, receiver for
condensed aroma-water, and the cylinders packed with wool for collecting the aroma.
Fig. 2. is a horizontal section, taken aty, of the digester, showing the arms of the
beater. Fig. 3. shows the evaporating dish and hood in vertical section. Figs. 4.
and 5. show the mortar or mixer in vertical and horizontal sections. Figs. 6, and 7,
show the press in vertical and horizontal sections.
In Fig. 1., A is the digester, B the boiler, C the supplementary boiler: D is the
cohobating tube; E the receiver for condensed aroma-water; F, E, the cylinders
containing wool: G is a flask open to the air, also containing wool, into which the
tube for passage of any unabsorbed aroma enters; and J is the water-jacket to the
digester. More than one receiver, E; and any convenient number of cylinders, F,
of any suitable shape, may be used. I do not confine myself to the form of cohobating
tube, D, shown, as any suitable form of distilling or cohobating column may be used;
the cork may be replaced by a cock, if desired, which is opened when the liquor is
sucked back from the digester into the boiler, as previously described. In the
digester, A, the syphon tube c, c, with ball and socket joint. h, and rose, , is attached
to the grid or perforated plate, d, and to the cover of the digester. The grid rests on
the lugs . The tea is charged in through the opening e, which is then closed by a
bung in which the cohobating tube is set. The rod, a, sliding in stuffing box, and

page_text: carrying arms, b, b, b, and spikes, U¹, can be partially rotated, so as to reach every
part of the charge, except so far as stopped by the syphon tube, 6, as shown in Fig. 2.
The manner of working the apparatus has been already fully described. It will be
evident that the relative positions and shapes of the digester and boilers, the form of
the syphon tube, and other subordinate details, may be modified without departing
from the essential features of the invention.
Fig. 3., A, shows the evaporating dish, which may be jacketed to be heated by
steam or it may be heated by direct flame. The sliding rod a, carries arms b, b, and
wires, for removing the film formed during evaporation from time to time. The
dish has a trough, d, and outlet tube e, for running off into a receptacle, the dilute
aroma-water condensed on the inside of the hood, B. The hood is shown with a
water-jacket, j. The tube e takes any uncondensed steam to a condenser.
The mortar or mixer, shown in Figs. 4 and 5, is preferably of cast brass or gun-
metal, and is nickel-plated, or preferably silver-plated. A valved outlet pipe may be
set in the cover, for passage of steam, if desired, but is not shown. The sliding rod a,
works in the steam-tight stuffing box, s, and carries agitators, b, b. The infusion
concentrated in the evaporating dish, is run hot into the mixer, A, to which heat is
applied, to complete the required concentration, when aromatised sugar, sometimes
moistened with aroma-water, is added; the cover is fastened on, and the agitator
is used to effect the mixture, the vessel being suitably heated as previously described.
The press, Figs. 6 and 7, is a strong vessel, resembling the mixer, having instead
of a sliding rod, a screw a, by which the platens b, b, b, b, are forced down upon inter-
mediate layers of aromatised wool that have been soaked with syrup or with syrupy
extract to exhaust the wool of its aroma. The press is heated during use.
is used to draw off the hot liquid product.
The cock
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;
(1.) The apparatus, consisting of a boiler and digester, connected by a syphon tube
as described, in which digester the tea is treated with water boiled by steam from the
boiler, and in part condensed from such steam, and in which the infusion formed is
sucked back from time to time, simultaneously with the collection of aroma with or
without aroma-water; also as an adjunct, a supplementary feeder or boiler connected
to the upper part of the digester.
(2.) The combination consisting of the cohobating tube connected to the digester,
with its adjuncts, that is, the vessel to condense aroma-water (when that is used), and
the vessels charged with wool to collect the volatile aroma.
(3.) The use of wool or of other suitable porous material for absorbing the volatile
tea-aroma in the manner described.
(4.) The process for obtaining, with a comparatively small proportion of water, a
strong tea infusion, simultaneously with the collection of the aroma, in the manner
described.
(5.) The use of an evaporating dish, with hood, trough for the collection of weak
aroma-water for use in treating fresh charges of tea, the instrument for removing
films, and the tube for carrying off steam, not condensed within the hood, to a
condenser.
(6.) The described processes for storing the aromatised wool with sugar; for
treating it in a close heated vessel with moistened sugar; and for applying sugar so
aromatised in the preparation of a confection; or in combination with a highly con-
centrated or partially dried infusion of tea to obtain a solid extract of tea, by use of
the described mixer or its equivalent.
(7.) The compression and drying of the spent tea-leaves to obtain a manure; or for
carbonisation in close vessels to obtain tea-charcoal and products of destructive
distillation.
Dated this 16th
J
1
3000