Improvements in the Manufacture of Liquid Extracts of Coffee or other Substances and in Apparatus for the Purpose.
Year: 1896

page_text: Date of Application, 5th Sept., 1890
Complete Specification Left, 8th June, 1897-Accepted, 10th July, 1897
να θυμι, του
Complete Specification Left, 8th June, 1897-Accepted, 10th July, 1897
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Liquid Extracts of Coffee or
other Substances and in Apparatus for the Purpose.
I, JOHN FREDERICK DUKE of 160 Rosendale Road, West Dulwich in the County
of London, Chemist, do hereby declare the nature of this invention to be as
follows:-
My invention has reference to the manufacture of liquid extracts of coffee or
other substances and its object is to obtain an extract with all its aroma and
fragrance (or other like qualities according to the particular substance treated)
intact and of any required strength.
liquid
The invention is more particularly intended for the manufacture of a
extract of coffee and I will hereinafter describe it as applied to coffee but it is
also applicable to the manufacture of other liquid extracts such for example as
scents or perfumes from flowers or the like.
According to my invention I submit ground coffee in a series of closed vessels
to the action of boiling water caused to pass under pressure from vessel to vessel
throughout the series the said vessels being connected together and those at the
two ends of the series being connected respectively with a boiler or hot water and
steam supply and with a closed liquid extract receiver.
From time to time-say about every 10 to 15 minutes more or less-the vessel
next the boiler is removed, the remaining vessels shifted one stage nearer the
boiler, and a fresh vessel charged with ground coffee put in position next the
extract receiver. Only as much water is supplied as is required in the final extract
so that it is not necessary to have recourse to evaporation according to the usual
practice in making liquid extract of coffee; and as all the vessels and the receiver
are closed the water that flows through the vessels and extracts the essential
elements from the coffee therein is not exposed to the oxidizing influence of the
air and it therefore reaches the receiver in the form of an extract without loss of
any of the aroma and fragrance of the coffee. It will be understood that the water
in passing through the series of vessels flows first through that in which the coffee
has become nearly spent by the water previously passed through it and then,
through those less spent until it reaches the vessel containing a fresh charge of
coffee. The flow of water is intermittent, only enough being supplied at a time
to approximately fill one vessel which has been about two thirds filled with ground
coffee.
In carrying out my invention I construct the vessels with an inlet at top and
an outlet at bottom and with pipes and appliances for connecting up in an air
tight manner the bottom of one vessel with the top of the next of the series or the
top of the first vessel with the boiler and the bottom of the last vessel with the
extract receiver or preferably with a cooling worm placed between the last vessel
and the receiver. The vessels have percolators or strainers at bottom to prevent
the coffee grounds choking the outlet. The pipe that connects the first vessel with
the boiler preferably has two branches communicating respectively with the water

page_text: and steam spaces of the boiler. The vessels are preferably supported on one or
more horizontal rails and are fitted with rollers or other anti-friction appliances to
facilitate their movement along the same during the required changes of position.
The apparatus is worked as follows:-supposing that all the vessels have been
charged with ground coffee and the process, has already been carried on until the
ground coffee in all the vessels except the last (which has just been put in place)
has become partly spent in progressive degrees. All the vessels except the last
are full of water, more or less in the form of coffee extract. Hot water is admitted
to the first or most spent vessel the amount being sufficient to fill up the vessel
charges with coffee the result of which is that the liquid flows from vessel to vessel
until the last or new one becomes filled. The hot water supply is then shut off
and steam is turned on to the first vessel. The steam gradually forces the water
or liquid out of the first vessel so that it is again caused to flow from vessel to
vessel and the last vessel delivers into the cooling worm or receiver an amount of
liquid in the form of an extract equal to that last supplied to the first vessel.
The first vessel is now disconnected from the boiler and the last vessel from the
worm. The first vessel is then removed, all the others pushed one stage nearer
the boiler, a fresh vessel placed next the worm and the connections re-made. The
apparatus is then ready for the admission of a fresh supply of water to the series
of vessels as before.
The extract can be drawn from the closed receiver into bottles ready for sale.
The strength of the extract obtained can be varied by varying the quantity of
water supplied at each charge and proportionately varying the number of vessels.
Dated this 5th day of September 1896
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.
Improvements in the Manufacture of Liquid Extracts of Coffee or
other Substances and in Apparatus for the Purpose.
I, JOHN FREDERICK DUKE of 160 Rosendale Road, West Dulwich in the County
of London, Chemist, 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 has reference to the manufacture of liquid extracts of coffee or
other substances and its object is to obtain without having recourse to the process
of evaporation an extract with all the aromatic oils or principles constituting the
aroma and fragrance of the coffee or other substance (or other like qualities
according to the particular substance treated) intact and of any required strength.
The invention is more particularly intended for the manufacture of a liquid
extract of coffee and I will hereinafter describe it as applied to coffee but it is also
applicable to the manufacture of other liquid extracts in which oxidation or
contact with the air is prejudical, such for example as scents or perfumes from
flowers or the like.
For the preparation of liquid extract of coffee according to my invention I
preferably use coffee roasted to a cinnamon color and not to blackness, and ground
whilst still hot, and I submit the freshly ground coffee in a series of hermetically
closed vessels to the action of boiling water caused to pass under pressure from
vessel to vessel throughout the series, the said vessels being connected together,
and those at the two ends of the series being connected respectively with a-boiler

page_text: or hot water and steam supply and with a closed liquid extract receiver. It is
essential that the vessels be hermetically closed so that the air is prevented from
coming in contact with the coffee when this is at a high temperature and thereby
oxidizing the aromatic oils or principles.
From time to time-say about every 10 to 15 minutes more or less-the vessel
next the boiler is removed, the remaining vessels shifted one stage nearer the
boiler, and a fresh vessel charged with ground coffee put in position next the
extract receiver. Only as much water is supplied as is required in the final extract
so that it is not necessary to have recourse to evaporation according to the usual
practice in making liquid extract of coffee; and as all the vessels and the receiver
are closed the water that flows through the vessels and extracts the essential
elements from the coffee therein is not exposed to the oxidizing influence of the
air and it therefore reaches the receiver in the form of an extract without loss of
any of the aroma and fragrance of the coffee. It will be understood that the water
in passing through the series of vessels flows first through that in which the coffee
has become nearly spent by the water previously passed through it and then
through those less spent until it reaches the vessel containing a fresh charge of
coffee. The flow of water is intermittent, only enough being supplied at a time
to approximately fill one vessel which has been about two thirds filled with ground
coffee.
In carrying out my invention I construct the vessels with an inlet at top and an
outlet at bottom and with pipes and appliances for connecting up in an air tight
manner the bottom of one vessel with the top of the next of the series or the top
of the first vessel with the boiler and the bottom of the last vessel with the extract
receiver or preferably with, a cooling worm placed between the last vessel and the
receiver. The vessels have percolators or strainers at bottom to prevent the coffee
grounds choking the outlet. The pipe that connects the first vessel with the boiler
preferably has two branches communicating respectively with the water and
steam spaces of the boiler. The vessels are preferably supported on one or more
horizontal rails and are fitted with rollers or other anti-friction appliances to
facilitate their movement along the same during the required changes of position.
Referring to the accompanying drawings,-Figures 1 and 2 are respectively a
side elevation and a plan illustrating the general arrangement of apparatus con-
structed according to this invention comprising by way of example a series of nine
extracting vessels.
Figure 3 is a central vertical section through one of the extracting vessels, and
Figure 4 is a plan of the lower part of the same, with the strainer omitted.
Figures 3 and 4 are drawn to a larger scale than Figures 1 and 2.
In these Figures,-A is a boiler adapted to be heated by means of a ring I of
gas jets fed by a gas supply pipe 2. B B B B B B B7 B8 B are a series of
nine extracting vessels arranged one behind the other and each adapted to run
by means of grooved wheels 3 upon a pair of horizontal rails CC which are carried
on pillars C and also serve to support the boiler B. A pipe 4 connects the bottom
or water space of the boiler B with the top of the first extracting vessel B, and a
pipe 5 connects the bottom of the vessel B' with the top of the next following
vessel B of the series, and so on until the last vessel 139 is reached, the other
successive vessels being connected by the pipes 6, 7, 8, 9, 10, 11, 12. The bottom.
of the last vessel B is fitted with a cock 13 which is adapted to deliver through a
cooling, worm (not shown) into an extract receiver (not shown).
Each extracting vessel consists of a top part 6 a middle part 2, and a bottom
part 3. The top part b¹ is adapted to be closed air-tight upon the middle part 63
by means of thumb-screws 14 and clamps 15 hinged to the middle part 6 The
middle part is provided with brackets and journals 16 which carry the grooved
wheels 3 (two on each side of the vessel) that run on the rails C. The bottom
part 63 is provided with a hemispherical percolator or strainer 17 of wire gauze
which retains the coffee grounds and prevents thein from choking the outlet.

page_text: .
Ribs or projections 18 are formed on the inner surface, of the bottom part &
against which the strainer 17 takes a bearing and by which it is supported in
such a manner as to leave a space between it and the inner surface of the vesse
for the collection of the liquor or extract passing through the strainer. Channels 19
are cut through the ribs 18 in order to facilitate the passage of the liquor to the
outlet 20. To this bottom outlet 20 is fitted by means of a screw union 21 the
lower end of one of the pipes 5 to 12 as the case may be according to the order of
position of the vessel in the series viz:-the pipe 9 in the case of the vessel B
for example. The top part of the vessel has an inlet 22 to which is fitted by
means of a screw union 23 the upper end of the preceding pipe in order of position,
viz: the pipe 8 in the case of the vessel B5.
The pipe 4 which connects the water space of the boiler A with the top of the
first vessel B¹, has a branch 41 which connects with the steam space of the boiler A.
Cocks 24 and 25 are provided so as to allow of establishing communication as may
required between the first vessel B¹ and either the steam or the water space of the
boiler A.
The apparatus is worked as follows:-Supposing that all the vessels B to B
have been charged with ground coffee and the process has already been carried
on until the ground coffee in all the vessels B to B except the last B (which has
just been put in place) has become partly spent in progressive degrees. All the
vessels B to B8 except the last B are full of water, more or less in the form of
coffee extract. Hot water is admitted from the boiler A through the cock 24 and
pipe 4 to the first or most spent vessel B¹ the amount being sufficient to fill
up the
vessel B freshly charged with coffee the result of which is that the liquid flows
from vessel to vessel until the last or new one B9 becomes filled. The hot water
supply is then shut off at the cock 24 and steam is turned through the cock 25 and
pipes 4 4 on to the first vessel B. The steam gradually forces the water or liquid
out of the first vessel B' so that it is again caused to flow from vessel to vessel and
the last vessel B9 delivers into the cooling worm or receiver (not shown) an amount
of liquid in the form of extract equal to that last supplied to the first vessel B.
The first vessel B is now disconnected from the boiler A and the last vessel B
from the worm. The first vessel B¹ is then removed, all the others pushed one
stage nearer the boiler, a fresh vessel place next the worm and the connections
are re-made. The apparatus is then ready for the admission of a fresh supply of
water to the series of vessels as before.
The extract can be drawn from the closed receiver into bottles ready for sale.
Instead of the boiler A a hot water tank may be employed disposed at such a
height relatively to the extracting vessels as to provide the necessary pressure to
force the water from vessel to vessel.
The strength of the extract obtained can be varied by varying the quantity of
water supplied at each charge or proportionately varying the number of vessels.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed; I declare that what I
Claim is:-
1. The process for the manufacture of liquid extract of coffee or other substance
of any required strength and without having recourse to the process of evaporation
consisting in subjecting the said substance in a series of connected and her-
metically closed vessels to the action of boiling water caused to pass under pressure
from vessel to vessel throughout the series, the vessel nearest the boiling water
supply being from time to time removed, the other vessels being then each moved
up one stage nearer and a fresh vessel (charged with the substance to be extracted)
heing placed at the furthest position from the boiling water supply all substantially
as and for the purpose hereinbefore described.
2. For carrying out the process referred to in the preceding Claim, the general

page_text: arrangement of apparatus substantially as hereinbefore described and as shown
by the accompanying drawings.
3. The special construction of extracting vessel substantially as described with
particular reference to Figures 3 and 4 of the accompanying drawings.
Dated this 5th day of June 1897.
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane. London, Chartered Patent Agents.