U.S. patent application number 14/725076 was filed with the patent office on 2015-10-08 for hybrid apparatus for preparing beverages.
The applicant listed for this patent is Nestec S.A.. Invention is credited to Christophe S. Boussemart, Thomas Hodel, Alexandre Kollep, Peter Preisig.
Application Number | 20150282665 14/725076 |
Document ID | / |
Family ID | 40458308 |
Filed Date | 2015-10-08 |
United States Patent
Application |
20150282665 |
Kind Code |
A1 |
Boussemart; Christophe S. ;
et al. |
October 8, 2015 |
HYBRID APPARATUS FOR PREPARING BEVERAGES
Abstract
A device for preparing hot beverages is provided and includes an
arrangement for circulating a liquid to a beverage supply exit; and
a combustion heating means, such as a burner, for supplying
combustion heat to the liquid that is circulated to the supply
exit. The combustion heating means can be associated: with an
electric heating means for supplying electric heat to the liquid
that is circulated to the supply exit and/or with a means for
regulating the heat supplied to the liquid from the combustion
heating means. The present disclosure further provides a device for
heating a liquid comprising combustion heating means and a cathalic
device for inhibiting flame formation.
Inventors: |
Boussemart; Christophe S.;
(Lugrin, FR) ; Kollep; Alexandre; (Lutry, CH)
; Hodel; Thomas; (Hagendorn, CH) ; Preisig;
Peter; (Herisau, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nestec S.A. |
Vevey |
|
CH |
|
|
Family ID: |
40458308 |
Appl. No.: |
14/725076 |
Filed: |
May 29, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12811336 |
Jun 30, 2010 |
|
|
|
PCT/EP2009/050684 |
Jan 22, 2009 |
|
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14725076 |
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Current U.S.
Class: |
99/281 |
Current CPC
Class: |
A47J 31/54 20130101;
A47J 31/56 20130101; A47J 31/005 20130101; A47J 31/545 20130101;
A47J 27/21 20130101 |
International
Class: |
A47J 31/56 20060101
A47J031/56 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 25, 2008 |
EP |
08100917.7 |
Mar 7, 2008 |
EP |
08152433.2 |
Claims
1. A device for preparing hot beverages, the device comprising: an
arrangement for circulating a liquid from a liquid supply to a
beverage supply exit; and a combustion heating means for supplying
combustion heat to the liquid that is circulated to the supply
exit, the combustion heating means being associated with an
electric heating means for supplying electric heat to the liquid
that is circulated to the supply exit, at least one of the
combustion heating means and the electric heating means being
associated with a means for regulating the heat supplied to the
liquid from the at least one of the combustion heating means and
the electric heating means, the regulating means comprising a
temperature sensor that is arranged to measure directly or
indirectly the temperature of the heated liquid for comparing the
measured temperature with a target temperature, the temperature
sensor being associated with one of: (i) the electric heating means
for adjusting the supply of the electric heat based on the
difference between the measured temperature and the target
temperature, the combustion heating means being arranged to supply
an amount of combustion heat to the liquid which is below the heat
required for the liquid to reach the target temperature; or (ii)
the combustion heating means for supply of the combustion heat
based on the difference between the measured temperature and the
target temperature, the electric heating means being arranged to
supply electric heat to the liquid which is below the heat required
for the liquid to reach the target temperature.
2. The device of claim 1, wherein the electric heating means
comprises a thermoblock having a metal-based body with a through
passage for the circulation of the liquid and one or more
resistances for supplying electric heat to the metal-based
body.
3. The device of claim 2, wherein the metal-based body with a
through passage is an aluminum body with a steel passage.
4. The device of claim 2, wherein the metal-based body has a
generally tubular shape with a generally helicoidal through passage
for the circulation of liquid.
5. The device of claim 2, wherein the combustion heating means is
arranged to supply heat to the liquid via the metal-based body of
the thermoblock.
6. The device of claim 1, wherein the electric heating means and
the combustion heating means are configured such that: the electric
heating means and the combustion heating means supply heat
simultaneously to the liquid; or only one at a time of the electric
heating means and the combustion heating means supplies heat to the
liquid.
7. The device of claim 1, wherein the combustion heating means
comprises a combustible supply arrangement for supplying
combustible material to a burner for consuming the combustible
material.
8. The device of claim 7, wherein the combustion heating means
further comprises a valve between the combustible supply
arrangement and the burner for controlling the supply of
combustible material from the supply arrangement to the burner.
9. The device of claim 8, wherein the valve is selected from the
group consisting of a variable valve and an on-off valve.
10. The device of claim 8, wherein the combustion heating means is
associated with means for regulating its heat supply, the
regulating means being arranged to control the valve.
11. The device of claim 1, wherein the combustion heating means is
associated with an ignition means.
12. The device of claim 11, wherein the ignition means is an
electric ignition means.
13. The device of claim 1, wherein the arrangement for circulating
a liquid comprises a pump for promoting the circulation of the
liquid in the arrangement.
14. The device of claim 1, wherein the device is arranged to be
powered with an electric current supply that is at least one of a
battery-type low voltage supply and the mains.
15. The device of claim 14, which is arranged for operation with
electric heating when powered by the mains and with combustion
heating when powered by the battery-type low voltage supply.
16. The device of claim 1, wherein the arrangement for circulating
a liquid comprises a head for containing an ingredient for the
preparation of the beverage, the head leading to the supply exit
and being selected from the group consisting of an extraction head
and an infusion head.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional application of U.S.
application Ser. No. 12/811,336, filed Jun. 30, 2010, which is a
U.S. national stage filing of International Application No.
PCT/EP09/050684, filed Jan. 22, 2009, which claims priority to
European Patent Application No. 08100917.7, filed Jan. 25, 2008,
and European Patent Application No. 08152433.2, filed Mar. 7, 2008,
the entire contents of which are incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus for preparing
beverages. The invention more precisely relates to dispensing
machines, such as mobile or portable coffee machines.
[0003] For the purpose of the present description, a "beverage" is
meant to include any liquid food, such as tea, coffee, hot or cold
chocolate, milk, soup, baby food, etc.
BACKGROUND ART
[0004] The beverage preparation apparatuses of the coffee machine
type which use prepacked or non-packed portions of a food substance
are very widespread among private individuals, and also in
municipalities, shopping centres and companies. The preparation
principle is based on the extraction of portions of the substance
by the passage through this substance of a quantity of cold or hot
liquid under high pressure, typically a pressure above atmospheric
pressure. The prepacked portions can be partially rigid capsules,
or else flexible bags, which are hermetically sealed or partially
open, or else a dose filter.
[0005] An example of a capsule is described in patent EP 0 512 4 68
B1. An example of a bag is described in patent EP 0 602 203 B1.
[0006] Such extraction systems have many advantages. On the one
hand, the individual packages are easy to use and require no
batching of coffee or other substances, in the machine. The user
places a capsule, a ground-coffee dose or other portions in the
machine, then presses a button to start extraction. On the other
hand, the individual packages are batched to deliver a beverage,
like a coffee, having the desired characteristics such as
sufficient character, flavour, foam or other important attributes.
When they are impermeable, they usually preserve the freshness of
the substance better, up to the time of extraction. Finally, the
preparation conditions, such as the temperature, pressure and
extraction time can be better controlled, thereby guaranteeing
relatively controlled and constant quality to the consumer.
[0007] An example of an extraction method is described in EP 0 512
470 B1.
[0008] To extract a beverage under pressure from these portions, of
the capsule or other type, it is necessary to use a relatively
powerful water pump such as an electric compressor and electric
heating elements that require significant amounts of electric power
to heat water to the appropriate temperature for preparing hot
beverages. These pumps and heating elements are usually supplied
with electric energy from the mains.
[0009] It is therefore difficult to move these preparation
apparatuses, for example on a trolley or simply by carrying them.
In fact, it would be an advantage to be able to make these
apparatuses more mobile so as to offer beverages in locomotion
means such as the train, plane, or in certain places such as
cinemas, theatres, and also in public places such as beaches,
parks, poolsides and other public or private places.
[0010] U.S. Pat. No. 6,739,241 discloses a camping drip coffee
maker in which a water is promoted from a reservoir to a brewing
basket via a tube by heating the tube with an open flame heater to
cause pressurisation of the water therein, whereby the
boiling/evaporating water is promoted to the brewing basket.
Whereas this type of flame heating of the water may prove to be
convenient to circulate boiling/evaporated water under the effect
of pressure for the purpose of making drip coffee, this heating
system is not appropriate to be adapted to prepare an espresso.
Indeed, the water which is pumped, usually mechanically, under
pressure through ground coffee to prepare an espresso coffee is
preferably maintained at a controlled temperature, typically at a
temperature within a range of a few degrees around 85.degree.
C.
[0011] WO2006/102980 discloses an espresso machine that can be
operated to prepare beverages without being connected to an
electric power network. The machine is powered with a battery. To
avoid extensive use of the battery to heat water used for the
preparation of the beverages, the espresso machine has a
thermally-insulated reservoir containing water that is preheated
using the mains prior to prepare beverages in an autonomous mode.
The water is then maintained at a sufficient temperature using the
battery in the autonomous mode. The autonomy of such beverage
machines can be of a few hours and thus provides a solution when
their use is intended within a relatively short period from the
time after the water has been preheated, for instance in trains,
planes, cinemas. . . . However, this machine is not optimal when
intended to be used only several hours or days after preheating the
water.
[0012] 082007/0199452 discloses a mobile or portable espresso
machine in which water is pumped from a reservoir by means of a
pressure gas actuated pump. The water is heated in the reservoir
(in which case the reservoir is insulated) or between the reservoir
and the machine's extraction head. The espresso machine has either
an electric heater, such as a thermoblock, or a combustion heater
such as a burner using solid and/or gaseous and/or liquid fuel.
[0013] More generally, a fuel gas burner that may be used for
cooking is disclosed in WO 2007/027379.
[0014] Even though combustion heaters may constitute an interesting
alternative to electric heating for certain type of mobile or
portable coffee machines, the known use of a combustion heater
leads to boiling and/or evaporation of the water, which is not
desirable for the preparation of espresso-type coffee or even tea.
Moreover, such combustion heaters are sometimes not well accepted
when the coffee machine is also intended to be used at proximity of
the electric power supply, in particular at home.
[0015] Therefore, there is still a need to provide a handy mobile
or portable espresso-type beverage machine that can be used to
prepare beverages at home, in an office or even in the absence of
an electric power network (mains) and which is suitable to prepare
hot beverages from a liquid heated at a controlled temperature.
SUMMARY OF THE INVENTION
[0016] The invention therefore relates to a device for preparing
hot beverages, in particular coffee or tea, comprising: an
arrangement for circulating a liquid from a liquid supply, e.g. a
water supply, to a beverage supply exit; and a combustion heating
means, such as a burner, for supplying combustion heat to the
liquid that is circulated to the supply exit.
[0017] The liquid supply may be in the form of a tank of liquid
having a capacity that is sufficient for supplying more than one
beverage.
[0018] In accordance with the invention, the combustion heating
means is associated with an electric heating means for supplying
electric heat to the liquid that is circulated to the supply
exit.
[0019] By providing a hybrid coffee machine, which works with a
combustion heating means and an electric heating means, the user
who does not want to have an appliance that needs a gas supply or
another combustion system at home or in the office for example,
typically for safety reasons, does not anymore need to buy a
separate appliance for going to places, typically outdoor places,
where he does not have access to the mains, such as a household or
industrial electric power supply providing typically about 110, 220
or 380 volt.
[0020] Electric heating means are for instance disclosed in WO
2004/006742 and in WO 2006/029763.
[0021] The electric heating means may comprise a thermoblock having
a metal-based body with a through passage for the circulation of
the liquid and one or more resistances for supplying electric heat
to the metal-based body.
[0022] Advantageously, the combustion heating means is arranged to
supply heat to the liquid via the metal-based body of the
thermoblock. Such a metal-based body may comprise a mass of
aluminium with a steel passage for the circulation of the liquid,
and/or it may form a sufficient thermal capacity that can provide a
more or less constant amount of heat to liquid circulating through
the thermoblock and absorb possible variations of the combustion
heat supply. The metal-based body may have a generally tubular with
a generally helicoidal through passage for the circulation of
liquid.
[0023] In order to adjust the temperature of the liquid, in
particular in the range of 70 to 95.degree. C., such as around
85.degree. C. for preparing a espresso coffee, the combustion
heating means and/or the electric heating means is/are preferably
associated with a means for regulating the heat supplied to the
liquid from the combustion heating means and/or the electric
heating means, the regulating means comprising usually a
temperature sensor.
[0024] In a first embodiment, the electric heating means is
associated with a temperature sensor that is arranged to measure
directly or indirectly the temperature of the heated liquid. In
this case, the electric heating means is arranged to: compare the
measured temperature with a target temperature; and adjust the
supply of electric heat based on the difference between the
measured temperature and the target temperature. In this
configuration, the combustion heating means may be arranged to
supply an amount of combustion heat to the liquid which is below
the heat required for the liquid to reach the target temperature
but does not need to be further regulated since the required heat
for the liquid to reach or approach the target temperature is
provided by the electric heating means.
[0025] In another embodiment, the combustion heating means is
associated with a temperature sensor that is arranged to measure
directly or indirectly the temperature of the heated liquid. In
this case, the combustion heating means is arranged to: compare the
measured temperature with a target temperature; and adjust the
supply of the combustion heat based on the difference between the
measured temperature and the target temperature. In such a
situation, the electric heating means may be arranged to supply
electric heat to the liquid which is below the heat required for
the liquid to reach the target temperature but does not need to be
further regulated since the required heat for the liquid to reach
or approach the target temperature is provided by the combustion
heating means.
[0026] In a further advantageous embodiment, the electric heating
means and the combustion heating means are associated with a
temperature sensor, optionally the same temperature sensor for both
heating means, that is arranged to measure directly or indirectly
the temperature of the heated liquid. In this case, the electric
heating means and the combustion heating means can be arranged to:
compare the measured temperature with a target temperature; and
adjust the supply of electric heat and/or combustion heat based on
the difference between the measured temperature and the target
temperature.
[0027] The regulating means may also comprise a flow meter to
monitor not only the temperature of the heated liquid but also the
flow rate, and thus the amount of liquid that requires heating.
[0028] The electric heating means and the combustion heating means
may be configured or configurable, in particular by the user, so
that: the electric heating means and the combustion heating means
supply heat simultaneously to the liquid; or only one at a time of
the electric heating means and the combustion heating means
supplies heat to the liquid.
[0029] The combustion heating means may comprise a combustible
supply arrangement for supplying combustible material to a burner
for consuming the combustible material. The combustible material
may be a solid and/or gaseous and/or a liquid fuel, that can be
subjected to a flame burning. However, by incorporating an
appropriate catalytic device in the burner, flame formation during
burning may be significantly inhibited or even substantially
suppressed, as will be discussed in greater details below. The
combustible supply arrangement may include a combustible supply
reservoir or tank, or a connector to a combustible supply network,
in particular for gas.
[0030] Usually, the combustion heating means further comprises a
valve between the combustible supply arrangement and the burner for
controlling the supply of combustible material from the supply
arrangement to the burner, in particular a variable valve, e.g.
allowing the passage of a variable flow of combustible, or a two
state on-off valve, e.g. a valve that merely has an open and a
closed position for controlling the flow of gas.
[0031] In such a case, the combustion heating means is
advantageously associated with means for regulating its heat
supply, the regulating means being arranged to control the valve.
When the valve is an on-off type of valve, the regulating means can
be arranged to control the periods of time during which the heating
means supply heat and, respectively, do not heat the liquid. When
the valve is a variable valve, the regulation means is preferably
arranged further to control the supply rate of the combustion
material for the heating, for instance the gas flow to the
burner.
[0032] One should bear in mind that each time the combustion
heating means is interrupted, it must be reignited to further
supply heat.
[0033] Usually, the combustion heating means is associated with an
ignition means, in particular an electric ignition means. For the
above reason, such an ignition means is preferably controlled by
the regulation means.
[0034] It is also possible to provide two parallel on-off vales,
i.e. a first valve for providing a minimum supply of combustible to
maintain a continuous or substantially continuous combustion and a
second valve for adjusting the heating power by intermittently
opening and closing as needed. In this case, there are no or fewer
combustion interruptions and no or fewer combustion
reignitions.
[0035] The arrangement for circulating a liquid comprises a pump
for promoting the circulation of the liquid in the arrangement, in
particular under pressure, e.g. up to 30 bar, such as in the range
of 1.5 to 25 bar, for instance 10 to 20 bar, typically to prepare
an espresso-type beverage. The pump may be electrically powered
and/or gas actuated, for instance a gas actuated pump as disclosed
in US2007/0199452.
[0036] The beverage preparation device is typically arranged to be
powered with an electric current supply that can be at least one of
a battery-type low voltage supply and the mains. The device may
comprise a housing for a battery and/or a connector for a low
voltage supply, for instance connectable to a cigarette lighter
type car connector.
[0037] The beverage preparation device may be arranged for
operation with electric heating when powered by the mains and with
combustion heating when powered by the battery-type low voltage
supply.
[0038] When the beverage preparation device has an electrically
powered pump, electric regulation means or other electric
components, a battery may be sufficient to power satisfactorily
such components when the heating is primarily provided by the
combustion heating means. In fact, when hot beverage preparation
devices are powered solely by an electric energy, the electric
heating requires about 95% of the consumed electric energy.
Therefore, it may be an advantageous combination for the autonomy
of the device while allowing a fine control of the temperature of
the liquid to provide a beverage preparation device with a
combustion heating means and an electric temperature regulation
means and pump, powered by a battery or another low voltage
electric supply.
[0039] The arrangement for circulating the liquid may comprise an
extraction and/or infusion head for containing an ingredient for
the preparation of the beverage, the extraction head leading to the
supply exit. The ingredient may be provided in the form of a
prepacked portion in a container such as a cartridge, bag, or other
appropriate packaging means. Alternatively, the ingredient can be
provided in the form of a non-packed portion, such as ground
coffee, directly introduced into the chamber of the extraction
module.
[0040] The invention also relates to a device for preparing hot
beverages, in particular coffee or tea. This device comprises: an
arrangement for circulating a liquid, such as water, from a liquid
supply to a beverage supply exit; and a combustion heating means,
such as a burner, for supplying combustion heat to the liquid that
is circulated to the supply exit. In accordance with the invention,
the combustion heating means is associated with a means for
regulating the heat supplied to the liquid from the combustion
heating means, the regulating means comprising usually a
temperature sensor.
[0041] The regulating means may particular be associated with a
temperature sensor that is arranged to measure directly or
indirectly the temperature of the heated liquid. In such a case the
regulating means can be arranged to: compare the measured
temperature with a target temperature; and adjust the supply of
combustion heat by the combustion means based on the difference
between the measured temperature and the target temperature.
[0042] This beverage preparation device may incorporate all the
above disclosed features or combination of features. In particular,
the combustion heating means is associated with an electric heating
element for supplying an electric heat to the liquid that is
circulated to the supply exit.
[0043] While the disclosed beverage preparation device is
particularly advantageous for providing mobile or portable devices
that may be suitable for inside and outside use, at home or out of
home, such a beverage preparation device may also be used as a
fixed device, for instance in a place with a combustible, in
particular gas, supply network to which the beverage preparation
device may be conveniently connected.
[0044] Another aspect of the invention relates to a device for
heating a liquid such as water, particular a device for cooking or
for incorporation into a device for preparing a beverage as
described above. However, the device may also be designed for use
on a self-standing basis. The heating device comprises: an
arrangement for containing a liquid to be heated; and a combustion
heating means for supplying combustion heat to the liquid within
the arrangement. The combustion heating means comprises an
arrangement for supplying combustible from a source of combustible
to a combustion area.
[0045] For example, the heating device is a device to dispense hot
water and/or is incorporated in a beverage preparation device to
heat water, or another liquid, used in the beverage preparation
process as discussed above. For instance, the heating device is
arranged to heat the liquid to the desired temperature for the
beverage preparation process or to preheat the liquid and circulate
it to an in-line heater such as an electric heater to adjust the
temperature for the beverage preparation process.
[0046] In accordance with the invention, the combustion heating
means further comprises within and/or adjacent to the combustion
area a catalytic device for inhibiting flame formation by
combustion of the combustible.
[0047] Such a flameless or flame-inhibited combustion may reduce
the combustion noise during heating and also prevents the formation
of undesirable and possibly dangerous flames extending out of the
heating device, especially when an elevated heating power is
needed.
[0048] Typically, the catalytic device becomes active for
inhibiting flame formation upon preheating thereof, for instance
when it becomes incandescent. In this case, the arrangement for
supplying combustible to the combustion area may comprise a control
means for supplying combustible to the combustion area at a low
rate during preheating of the catalytic device, when combusting
still produces flames, and at a high rate upon preheating of the
catalytic device, when combustion produces substantially no
flames.
[0049] The heating device may have a housing containing the
combustion area and one or more passages, such as chimneys, in
particular extending along the arrangement for containing the
liquid to be heated, for evacuating combustion gases from the
combustion area to outside the housing. In this case, the low rate
of supply of combustible is preferably such that combustion flames
generated during preheating of the catalytic device are at least
inhibited from extending outside the housing via the passages.
[0050] During preheating, the heating device may be arranged to
measure directly or indirectly a temperature of the catalytic
device to monitor whether or not the catalytic device has reached
its temperature at which it becomes active. For example, the
heating device includes a temperature sensor at or nearby the
catalytic device. In a simpler embodiment, the heating device can
be arranged to estimate by a predictive model the activation of the
catalytic device, for instance a model based on experimental
results. In particular, the length of a particular preheating
period at low combustion supply rate may be set as a function of
the time span from a previous heating cycle, the longer the time
span between two consecutive heating cycles the longer the
preheating period. In this case, the preheating period is maximal
when the device is used for the first time for heating after having
been switched on.
[0051] Usually, the combustion heating means comprises at least one
combustible supply conduit associated with a control valve to
adjust a rate of supply of combustible to the combustion area via
the supply conduit.
[0052] Such a control valve may be a variable valve. In this case,
during preheating, the flow rate via this valve may be gradually
increased in accordance with the degree of activation of the
catalytic device, when the catalytic device has a
temperature-related progressive activity.
[0053] The combustion heating means may comprise a plurality of
combustion supply conduits, each conduit being associated with a
corresponding control valve, in particular an on-off control valve.
In this case, only one or part of the control valves may allow the
passage of combustible to the combustion area during preheating to
maintain a low overall flow rate of combustible to the combustion
area.
[0054] A common combustion supply conduit can be associated with a
plurality of control valves, in particular parallel valves, the
outlets of which join in or upstream the common combustion supply
conduit. In a variation, the common combustion supply conduit may
be replaced by a plurality of common combustion conduits having
their inlets in fluid connection, the outlets of the valves being
directly or indirectly connected to the connected conduit inlets.
In this case, the distribution of the combustible delivered by the
supply conduits to the combustion area may be improved.
[0055] The catalytic device may have a porous, foraminate,
perforated or grid-like structure, in particular a plate-like
structure, arranged for a flow of said combustible therethrough.
The catalytic device can have an active surface made of or
comprising one or more noble metals as a catalyst, for instance the
catalytic device is integrally made of active material or has a
core with a coating or layer of active material where exposed to a
flow of combustible. Suitable catalytic materials include, for
example, Metflame.TM. A supplied by Infrared Dynamics, Metflame.TM.
PB10 provided by Porvair Advanced Materials, catalytic materials
from Catalytic Combustion Corporation in Bloomer, Wis. 54724, USA,
and from Oglesby Butler in Carlow, Ireland.
[0056] For certain applications, in particular the preparation of
beverages such as coffee of tea, the temperature of the heated
liquid should be specifically adjusted to the specific application
and maintained within a relatively narrow span, say at a selected
temperature level in a range below the boiling point of e.g. 35 to
95.degree. C., in particular 65 to 90.degree. C., within a maximum
temperature deviation of +/-2 to 3.degree. C. around the selected
temperature. The arrangement for containing a liquid to be heated
may include a temperature sensor for directly or indirectly
measuring the temperature of the liquid, e.g. water, during heating
thereof and an arrangement for adjusting the combustible supply
rate to the combusting area to heat the liquid to the selected
target temperature. Hence, the control means for supplying
combustible is further arranged for adjusting the combustible
supply to heat said liquid to said target temperature. Such a
supply adjustment may be carried out by means of a valve allowing a
variable flow rate or by means of several conduits, each associated
with a corresponding (on-off) valve and which may be operated
independently from one another to allow fine tuning of the
combustion.
[0057] The heating device of the invention may incorporate any
suitable feature or combination of features disclosed in relation
with the above described beverage devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] The invention will now be described with reference to the
schematic drawings, wherein:
[0059] FIG. 1 shows a schematic arrangement of components of a
beverage preparation device according to the invention;
[0060] FIGS. 2 to 6 show various details of a heating system of a
beverage preparation device according to the invention; and
[0061] FIGS. 7 to 12 show various schematic views and details of an
embodiment of a liquid heating device which may be implemented into
a beverage preparation device according to the invention.
[0062] More particularly, FIGS. 7 and 8 illustrate the external
aspect of the heating device (with and without lid), FIG. 9 shows a
side perspective view of part of the inside of the device, FIG. 10
shows a front cross-sectional view of the device, FIG. 11 shows an
enlarged view of a detail A of FIG. 10, and FIG. 12 shows a view of
the combustible circulation arrangement of the heating device.
DETAILED DESCRIPTION
[0063] FIG. 1 discloses a water circulation and heating system 1 of
a liquid beverage preparation device, in particular a coffee,
espresso and/or tea preparation machine, in accordance with the
invention.
[0064] System 1 comprises a reservoir 2 for containing the liquid,
in particular water, a pump 3 for promoting the circulation of the
liquid, in particular under pressure, a thermoblock 4 with an
electric thermal resistance 5 and a burner 6 with a combustible
tank 7 for heating the circulating liquid and an extraction head 8
with a beverage supply exit 9.
[0065] Thermoblock 4 has a mass of metal, in particular an
aluminium body incorporating a steel passage such as a steel tube
extending through the body, through which the liquid is circulated
from pump 3 towards extraction head 8 and thereby appropriately
heated. This thermoblock's mass forms a thermal capacity to smooth
or absorb the effect of variable heat supply by resistor 5 or
burner 6 and/or variable heat consumption by the circulating
liquid. However, in order to limit the thermal inertia the amount
of material of metal mass 41 is limited by the presence of a
central through-opening that can be provided through mass 41 (see
in particular FIGS. 3 and 5).
[0066] As shown in FIG. 1, burner 6 is associated with thermoblock
4 and arranged to supply a combustion heat to the circulating
liquid via thermoblock 4 by supplying combustion heat to the bottom
part of thermoblock 4.
[0067] Thermoblock 4 is so arranged above burner 6 to be heated by
the consumption of combustible at burner 6, when the burner is in
use. Hence, burner 6 is arranged relative to thermoblock 4 so as to
maximise heat transfer from the consuming combustible to
thermoblock 4 and therefrom to the circulating liquid.
[0068] Furthermore, resistor 5 and combustible heater 6,7 are
associated with a thermal regulator (not shown). The regulator
includes a temperature sensor arranged to measure the temperature
of the heated liquid, for instance at the liquid exit of
thermoblock 4, or within thermoblock 4. The temperature of the
thermoblock's metal mass may be measured in order to obtain an
indirect measure of the temperature of liquid. The regulator
further comprises a control unit, e.g. including a controller or
microprocessor, connected to the temperature sensor for comparing
the measured temperature to a target temperature. The control unit
is further connected: on the one hand, to an electric valve and an
electric ignitor of burner 6 for controlling the supplied
combustion heat; and, on the other hand, to an electric switch or
variator connected to resistor 5 for controlling the supplied
electric heat. To allow a finer regulation of the temperature of
the circulating liquid, the thermal regulator may be associated
with a flow meter 55 to measure the flow rate of the circulated
liquid and determine precisely the required heat for heating the
circulating liquid. For regulating the supplied heat, in particular
from burner 6, the control unit may include a predictive model to
anticipate the required heat for adjusting the temperature of the
circulating liquid.
[0069] System 1 is further associated with a supply of electric
power, from the mains and from a low voltage battery, allowing two
modes of electric operations, in a plugged or unplugged mode.
[0070] FIGS. 2 to 6, in which the same numeric references designate
the same elements, show in greater details a heating system of a
beverage preparation device according to the invention. More
specifically, FIG. 2 shows a perspective view of the thermoblock 4,
burner 6 and combustible tank 7. FIG. 3 is an exploded view of
thermoblock 4 and burner 6 shown in FIG. 2. The same structural
elements of the heating system are shown in FIGS. 4 and 5, FIG. 4
being a side view and FIG. 5 a cross-sectional view according to
line and arrows E-E indicated in FIG. 4. FIG. 6 schematically shows
the general flow path of liquid through thermoblock 4.
[0071] As shown in FIG. 2, combustible tank 7 is connected via a
solenoid valve 71 and duct 75 to burner 6 in order to supply
combustible, in particular in the form of gas, to burner 6. The
flow of gas from burner 6 is adjusted by the control of solenoid
valve 71.
[0072] Thermoblock 4 shown in FIGS. 2 to 6 has an inner generally
tubular metal mass 41 with a duct (not shown) for the circulation
of water to be heated to be heated in thermoblock 5 during use.
Metal mass 41 is enclosed in an outer casing 45 made of thermal
insulation material. As shown in FIG. 4, metal mass 41 is
associated with electric thermal resistance 5, permitting electric
heating of thermoblock 4, and sensor connector 55 for measuring one
or more a characteristics of thermoblock 4 and/or of the liquid,
for example water, circulating therethrough during use, such as the
flow rate of the circulating water and/or the temperature thereof
and/or of mass 41. Furthermore, a suitable flow path 49 through the
thermoblock's metal mass 41 for the liquid to be heated via
thermoblock 4 is generally shown in FIG. 6, arrows 49' and 49''
indicating the entry and the exit, respectively, of liquid
circulating through mass 41. Flow path 49 is generally helicoidal
and extends along the periphery of the generally tubular mass
41.
[0073] In addition to an electric heater 5, thermoblock 4 is
associated with a combustible heater 6, in the form of burner, as
depicted in FIGS. 2 to 5. Burner 6 connected at the end of gas
supply duct 75 extends into thermoblock 4 through outer casing 45.
The upper part of outer casing 45 has a pair of openings 46 for the
exit of exhaust combustion gases and a series of lateral openings
47, in the form of slits, for the passage of air.
[0074] Burner 6 has a combustible distribution chamber 62 with a
generally V-shaped cross-section 63 that generally matches the
lower part of thermoblock 4 and that leads via a tubular connector
63' containing a burner nozzle 61 to duct 75, nozzle 61 being
located at the bottom of distribution chamber 62 and extending
therebelow. An opening 64 is provided for the passage of air
through tubular connector 63' to burner nozzle 61. A metal sheet 66
for conducting heat, for example made of brass, extends around a
bottom part of metal mass 41. Conductor sheet 66 and metal mass 41
having therebetween a heat exchanger 66' for transferring
combustion heat to metal mass 41. Also shown in FIG. 5, burner
nozzle 61 and distribution chamber 62 are covered with a porous
protective inlay 68 against fire backlash. Inlay 68 is itself
covered with a porous catalyser layer 67 for the combustion. Burner
nozzle 61 is further associated with an ignitor 65 for igniting
combustion. Ignitor 65 extends through distribution chamber 62.
[0075] During use of system 1 to prepare a beverage, liquid is
pumped from reservoir 2 by pump 3, usually electric, via
thermoblock 4 to extraction head 8 and through a batch of beverage
ingredient, in particular a coffee or tea capsule or pod housed in
head 8, and then to beverage exit 9 where the beverage can be
collected in a recipient, in particular in a cup or mug, located
thereunder.
[0076] In the plugged mode, system 1 is connected to the mains and
the heat is provided electrically by resistor 5. In this mode,
system 1 can be operated and regulated like in known beverage
preparation devices.
[0077] In the unplugged mode, system 1 is electrically powered by a
low voltage battery (not shown) that supplies electric energy to
pump 3, to the regulator, to the electric valve and the ignitor 65
of burner 6. In this unplugged mode, the regulator controls the
burner's valve and ignitor 65 to adjust the combustion heat
transferred to the circulating liquid via thermoblock. More
specifically, during use, gas, or another suitable combustible, is
guided from tank 7 along duct 75 via valve 71 to burner nozzle 61
where it is mixed with air passed to nozzle 62 via opening 64. The
mixture is then distributed in distribution chamber 62 and
circulates via porous inlay 68 to porous catalyst 67 where the
mixture is consumed. The hot combustion oases flow around metal
mass 41 to exhaust openings 46 in the thermal insulating casing
45.
[0078] Whether the system is operated in the plugged or unplugged
mode, the electric and/or combustion heat is passed from metal mass
41 to the water circulating in mass 41 along flow path 49 in a duct
(not shown) extending through mass 41. The duct of metal mass 41
normally has a water inlet that leads incoming water coming from
pump 3 into mass 41 and a water outlet that guides exiting water
from mass 41 to extraction head 8. Such water inlet and outlet may
be located on the same face of metal mass 41 or on different faces,
for instance opposite faces, of mass 41.
[0079] In a variation, electric resistor 5 and burner may be used
in the same beverage preparation cycle to increase the produced
heat and/or provide a finer adjustment of the temperature.
[0080] FIGS. 7 to 12 in which the same numeric references generally
designate the same elements, show a particular device 1' for
heating a liquid such as water, in particular for incorporation
into a device for preparing a beverage similar to the one described
above. However, the device may also be designed for use on a
self-standing basis for cooking or for dispensing hot water, e.g.
for a subsequent preparation of instant coffee or tea or soup, or
an infusion, etc. . . . in a cup.
[0081] Heating device 1' comprises within a housing 23: an upper
arrangement, such as a vessel 2', for containing a liquid to be
heated 2; an intermediate combustion heater 6' for supplying
combustion heat to the liquid within arrangement 2'; and a lower
cavity 7' for receiving a combustible tank 7. Furthermore, housing
23 has a side compartment 24 containing electric supply
arrangement, such as a series of batteries or an accumulator 51 or
alternative connector device to the mains or to a car accumulator
for instance via a cigarette lighter, and a printed circuit board
52 with a controller forming an electric control unit of heating
device 1'. Printed circuit board 52 may be connected to a
user-interface (not shown) for instance mounted on compartment 24
or elsewhere, as appropriate.
[0082] Vessel 2' has a bottom 26, sidewalls 27 and a lid 21 with a
handle 22. Lid 21 may have a thermal insulation. For filling vessel
2' via its mouth with water, lid 21 will of course be removed. For
dispensing water from vessel 2' a tubular conduit is provided. In
this embodiment, tubular conduit 48 extends from a bottom region of
vessel 2' downwards so as to guide liquid out of vessel 2' under
the effect of gravity. A downstream valve (not shown) may be
mounted on tubular conduit 48 to control the outflow of liquid.
[0083] Combustion heater 6' has a bottom 601 extending across
housing 23 and a perforated plate 604 spaced thereabove by spacers
601'. Perforated plate 604 is arranged to promote the distribution
of combustible flowing therethrough into a combustion area 608
located thereabove. A pair of tubes 602,602' extend into heater 6'
between bottom 601 and plate 604 for the supply combustible from a
source 7 of combustible via a conduit 72, valve arrangement 71' and
conduit 75'.
[0084] Outside burner 6', tubes 602,602' have a series of
peripheral openings 603 for the intake of air from lower cavity 7',
housing 23 having a series of openings 25 for the circulation of
air into the lower cavity.
[0085] During use, air is drawn into tubes 602,602' via openings
603 under the effect of the combustible flow in these tubes. Within
tubes 602,602' combustible is then mixed with air to permit
subsequent combustion. This mixture escapes from tubes 602,602'
between bottom 601 and plate 604 and then distributed via
perforated plate 604 in combustion area 608. A pair of facing
ignition electrodes 606 protruding from protection sheaths 607 are
arranged to ignite combustion in combustion area 608. Such
electrodes 606 may be powered by batteries 51 and controlled by
control unit 52 for igniting combustion whenever necessary.
[0086] Advantageously, control unit 52 is also connected to a
combustion detector (not shown) associated with combustion area 608
so as to detect any combustion incident, e.g. unwanted extinction,
and allow control unit 52 to take the appropriate corresponding
steps, e.g. reignite combustion via electrodes 606 or interrupt
combustible supply.
[0087] A series of generally upright L-shaped guide members 609 are
arranged all around combustion area 608 and extend underneath
vessel 2' and up between vessel 2' and housing 23. Guide members
609 delimit with vessel 2' and housing 23 a series of channels or
chimneys for evacuating exhaust gases from combustion area 608
outside device 1' in such a manner as to maximise the heat transfer
between exhaust the exhaust gases and vessel 2'.
[0088] Furthermore, through-openings 25' are provided in housing 23
at the level of these channels or chimneys to allow the intake of
ambient air for avoiding overheating at the periphery of vessel 2',
in particular when vessel 2' is only partly filled with liquid.
However, in some embodiments and depending the intended use, it may
be preferable to avoid such through-openings along the channels or
chimneys, especially since these openings may allow an early escape
of flames generated during preheating and reduce the heat transfer
from the exhaust gases to vessel 2'.
[0089] In accordance with the invention, combustion heater 6'
further comprises within and/or adjacent to combustion area 608 a
catalytic device 605 for inhibiting flame formation by combustion
of the combustible.
[0090] Catalytic device 605 may have a porous, foraminate,
perforated or grid-like structure, in particular a plate-like
structure, arranged for a flow of said combustible therethrough.
Catalytic device 605 can have an active surface made of or
comprising one or more noble metals as a catalyst, such as platinum
or an alloy thereof. For instance, catalytic device 605 is
integrally made of active material or has a core with a coating or
layer of active material where exposed to a flow of
combustible.
[0091] As illustrated in FIGS. 9 to 11, catalytic device 605 is
located above plate 604 and is generally parallel thereto.
[0092] Typically, catalytic device 605 becomes active for
inhibiting flame formation upon preheating thereof, for instance
when it becomes incandescent. Hence, at start-up, when combustible
is ignited in combustion area 608, flames will be formed above
catalytic device 605. This initial combustion will heat up
catalytic device 605 which, when the activation temperature is
reached, will become active for the inhibition of combustion-formed
flames. This will lead to a noise reduction of the combustion and
allow larger supply of combustible to the combustion area 608
without risk of formation of flames that would escape via the
evacuation chimneys or channels formed along vessel 2', and hence
allow a safe increase of the heating power of the system.
[0093] For this purpose, the arrangement for supplying combustible
to combustion area 608 may comprise a control means for supplying
combustible to the combustion area 608 at a low rate during
preheating of the catalytic device 605, when combusting still
produces flames, and at a high rate upon preheating of the
catalytic device 605, when combustion produces substantially no
flames.
[0094] As shown in FIGS. 9 to 12, combustible tank 7 is on the one
hand mechanically secured in cavity 7' to bottom 601 via connector
73 and has a fluid connection via pipe 72 to a valve arrangement
71'. This arrangement 71' includes a pair of parallel on-off valves
connected on their inlet side to pipe 72 and on their outlet side
to the parallel combustible supply tubes 602,602' via a common
T-shaped connecting tube 75'. The flow in each supply tube 602,602'
is about identical and controlled by control unit 52 via the
corresponding valve of arrangement 71'.
[0095] Hence, during preheating of catalytic device 605, only one
valve of arrangement 71' will be opened for allowing combustible to
be supplied at a reduced rate into combustion area 608. When the
preheating of catalytic device 605 is complete both valves of
arrangement 71' may be opened. It should be noted that these two
valves may be dimensioned for providing different supply rates. For
example, the valve opened during preheating may be dimensioned for
providing a smaller supply rate than the other valve.
[0096] The preheating valve may be dimensioned to provide as much
combustible as possible to combustion area 608 for a combustion
which during preheating generates flames that however do not
propagate out of housing 23. The second valve may be dimensioned to
allow full capacity of combustion supply to combustion area 608 and
is opened once catalytic device 605 is activated, i.e. during
normal operation.
[0097] The second valve may be used also to adjust the heating
profile during normal operation and may be intermittently opened or
closed as needed to increase or reduce the amount of combustible
supplied to combustion area 608.
[0098] This configuration for example may be of interest for fast
heat up of the liquid contained in vessel 2', e.g. heating water to
a predetermined temperature, in particular below its boiling point,
for subsequent dispensing.
[0099] The preheating valve may be dimensioned to provide just
enough combustible for maintaining the temperature of the liquid in
vessel 2' and/or maintain continuous combustion in combustion area
608. The second valve may be used to adjust the heating profile
during normal operation.
[0100] This configuration for example may be of interest when
vessel 2' is used not merely to heat liquid but for cooking, e.g.
non-instant soup that needs to be maintained for an extended period
of time at a temperature closing to boiling.
[0101] To determine when the preheating is sufficient, heating
device 1' may be arranged to assess the state of activation of
catalytic device 605 by measuring directly or indirectly the
temperature of catalytic device 605. This may be achieved by means
of a sensor, in particular a resistive-type is for example
incorporated in catalytic device 605 for a direct measure or in or
against bottom 601 nearby catalytic device 605 for an indirect
measure. For such configurations, this temperature sensor may be
connected to control unit 52 which also controls the valves of
valve arrangement 71'.
[0102] To simplify the architecture of heating device 1', in
particular to avoid the need of a temperature sensor for measuring
the temperature of catalytic device 605, the preheating duration
may merely be evaluated by control unit 52 based on a more or less
sophisticated predictive model implemented into control unit 52,
e.g. derived from experimental results and, optionally, the actual
history of use of device 1'. In particular, the length of a
particular preheating period at low combustion supply rate may be
set as a function of the time span from a previous heating cycle,
the longer the time span between two consecutive heating cycles the
longer the preheating period. In this case, the preheating period
is maximal when the device is used for the first time for heating
after having been switched on.
[0103] For certain applications, in particular the preparation of
beverages such as coffee of tea, the temperature of the heated
liquid should be specifically adjusted to the specific application
and maintained within a relatively narrow span, say at a selected
temperature level in a range below the boiling point of e.g. 35 to
95.degree. C., in particular 65 to 90.degree. C., within a maximum
temperature deviation of +/-1, 2 or 3.degree. C. around the
selected temperature.
[0104] For this purpose, vessel 2' includes a temperature sensor
28, e.g. of the resistive type, on bottom 26 for measuring the
temperature of the liquid, e.g. water, during heating thereof.
Sensor 28 is connected to control unit 52 which in turn controls
valve arrangement 71' so that the proper amount of combustible is
supplied from tank 7 to combustion area 608 for the liquid to reach
the selected temperature.
[0105] As mentioned above, heating device 1' shown in FIGS. 7 to 12
may be incorporated into a machine for preparing beverages such as
coffee, tea or soups. For example, outlet 48 may be connected to a
pump and lead to an extraction head of the type shown in FIG. 1 to
form a beverage preparation system (not shown). Such system may
further include an electric heater, before or after the pump. In a
variation, the burner with the catalytic device may be mounted
in-line either alone or in combination with an electric heater such
as a thermoblock, in particular against the electric heater, for
example as generally illustrated in FIGS. 3 to 5.
[0106] Heating device 1' illustrated in FIGS. 7 to 12, may be
modified so that the combustible supply conduits are separately
connected to a corresponding valve of the valve arrangement, each
valve controlling separately the passage of combustible in the
supply conduit connected thereto.
[0107] Alternatively, the combustion heating means may have only
one combustible supply conduit extending into the combustion heater
6'. Such a combustible supply conduit may be connected to a
variable control valve that is conceived for allowing the supply of
combustible at different rates. In this case, during preheating,
the flow rate via this valve may be gradually increased in
accordance with the degree of activation of the catalytic device,
when the catalytic device has a temperature-related progressive
activity. Later on, during steady state operation, the adjustment
of the combustible supply rate may be easily adjusted by
controlling this valve, e.g. to provide an appropriate heating
profile for the liquid in the vessel.
[0108] A single combustible supply conduit may be connected to an
arrangement of a plurality of parallel on-off valves of the type
similar to the arrangement 71' shown in FIG. 12. Such valve
arrangement may then be connected via corresponding converging
connecting tubes to the same combustible supply conduit.
[0109] Moreover, for a finer adjustment of the supply rate, it is
possible to increase the number of valves. However, it is also
possible, with a small number of on-off valves to adjust the
heating power over time by intermittently commuting at least one
on-off valve.
[0110] It is of course also possible to increase the number of
supply conduits that extend into the burner.
* * * * *