WO2010043251A1

WO2010043251A1 - An apparatus for preparing a beverage

Info

Publication number: WO2010043251A1
Application number: PCT/EP2008/063806
Authority: WO
Inventors: Marcel Hendrikus Simon Weijers
Original assignee: Inventum Group Bv; Alpha-Beta Holding B.V.
Priority date: 2008-10-14
Filing date: 2008-10-14
Publication date: 2010-04-22

Abstract

An apparatus (1) for preparing a beverage comprises a first container (4) and a second container (5) for containing a liquid (8). The first and second containers (4, 5) are in liquid communication with each other. The apparatus (1) also comprises a heater (12) for heating a liquid (8) in the first container (4), a mixing chamber (16) for mixing heated liquid (8) of the first container (4) and liquid (8) of the second container (5), and a tapping valve (13) located downstream of the mixing chamber for building up a liquid pressure in the first and second containers (4, 5) and in the mixing chamber upon heating a liquid (8) in the first container (4) above its boiling temperature. The first container (4) is in vapour communication with the second container (5). The locations (10, 11) at the first and second containers (4, 5) where the first and second containers (4, 5) are in vapour communication with each other are disposed at a higher height level than those where the first and second containers (4, 5) are in liquid communication with each other. The first and second containers (4, 5) are provided with first and second outlets (14, 15), respectively, which are disposed at a lower height level than the locations (10, 11) at the first and second containers (4, 5) where the first and second containers (4, 5) are in vapour communication with each other. The first and second outlets (14, 15) are in communication with the mixing chamber (16).

Description

An apparatus for preparing a beverage

The present invention relates to an apparatus for preparing a beverage, comprising a first container and a second container for containing a liquid, the first and second containers being in liquid communication with each other, a heater for heating a liquid in the first container, a mixing chamber for mixing heated liquid of the first container and liquid of the second container, a tapping valve located downstream of the mixing chamber for building up a liquid pressure in the first and second containers, and in the mixing chamber upon heating a liquid in the first container above its boiling temperature.

Such an apparatus for preparing espresso is known from DE 195 00 686. In the known apparatus the heater increases the temperature of water in a first compartment such that steam arises above the liquid water level. Due to the steam pressure the liquid water pressure rises. A second compartment of the known apparatus is in liquid communication with the first compartment via a permeable barrier layer. The liquid water in the second compartment is colder than the heated water in the first compartment. When the downstream tapping valve is opened the hot liquid water in the first compartment will flow via the permeable barrier layer into the second compartment and mix with the cold water of the second compartment. After mixing, the water has a temperature between the initial high temperature of the water in the first compartment and the relatively low temperature of the water in the second compartment before opening the valve. For preparing espresso it is desired to create a water temperature below 100 ⁰C, but at an elevated pressure. After closing the tapping valve the flow stops and the relatively hot water in the second compartment cools down to become ready for a next cycle. A disadvantage of the known apparatus is that the final water temperature after mixing will vary from cycle to cycle.

The object of the invention is to provide an apparatus for preparing a beverage which prepares a liquid of stable temperature and elevated pressure. This is achieved by the apparatus according to the invention which is characterized in that the first container is in vapour communication with the second container, and the locations at the first and second containers where the first and second containers are in vapour communication with each other are disposed at a higher height level than those where the first and second containers are in liquid communication with each other, and wherein the first and second containers are provided with first and second outlets, respectively, which are disposed at a lower height level than the locations at the first and second containers where the first and second containers are in vapour communication with each other, which first and second outlets are in liquid communication with the mixing chamber.

Under operating conditions a certain amount of water will be supplied to the apparatus. In practice the first and second containers will be partly filled such that a certain space exists between the liquid or water level and an upper wall of each of the containers. Due to the positioning of the locations at the first and second containers where the first and second containers are in vapour and liquid communication with each other the liquid in the first and second containers will be balanced at the same height level. In case of identical containers disposed at the same height level the liquid level and the liquid volume in each of the containers will be identical. Due to minimized liquid flow between the first and second containers and a similar pressure above the liquid level in both containers, the mixing ratio between the heated and non- heated liquid as well as the liquid temperature in mixed condition after opening the tapping valve can be kept within narrow limits.

In a preferred embodiment the first and second outlets and/or the locations at the first and second containers where the first and second containers are in liquid communication with each other are disposed at bottom portions of the first and second containers, respectively. This has the advantage that after preparation of a beverage all liquid has disappeared from the first and second containers.

The shapes and dimensions of the first and second containers may be substantially the same. This provides the opportunity of creating a continuous ratio between hot water coming from the first container and cold water coming from the second container.

The first and second containers may be cylindrically shaped. The cross-sectional circumference may be circular, rectangular, or have an alternative shape.

In a particular embodiment the first and second containers are integrated in a housing and separated by a wall within the housing. In this case the apparatus may be rather compact.

The first and second containers may be in vapour communication with each other via a vapour communication line, for example a tube, a pipe, or the like. This means that there may be a certain distance between the first and second containers.

The first and second containers may be in liquid communication with each other via a liquid communication line, which may be formed of a tube or pipe, as well.

In a particular embodiment the second container at least partly surrounds the first container, or the first container at least partly surrounds the second container. Preferably, the first and second containers are thermally separated by an insulated wall.

In a preferred embodiment the first and second outlets, the liquid communication line and the mixing chamber are integrated so as to obtain a compact apparatus.

The invention will hereafter be elucidated with reference to the very schematic drawings showing different embodiments of the invention by way of example. Fig. 1 is a cross-sectional view of an embodiment of an apparatus according to the invention.

Figs. 2a and 2b are partly similar views as Fig. 1 on a smaller scale, illustrating different liquid levels in the apparatus . Figs. 3a-3f are partly similar views as Fig. 1 on a different scale of alternative embodiments of the apparatus.

Fig. 4 is a similar view as Fig. 3b of a more practical embodiment . Fig. 1 shows an embodiment of an apparatus 1 for preparing a beverage. The apparatus 1 is suitable for preparing coffee, for example, but alternative beverages are conceivable. Water of a certain temperature and pressure is prepared and supplied to a brew chamber 2 in which a soluble or extractable substance is received, for example a coffee pad 3. For certain beverages, such as coffee, it appears to be relevant that the water has a temperature below 100 ⁰C and an elevated pressure above atmospheric pressure. In case of increasing the water pressure by steam due to heating the water, the water temperature may exceed 100 ⁰C. This is, however, undesired for preparing coffee in terms of its flavour. Therefore, the apparatus according to the invention controls the water temperature such that it is below 100 ⁰C whereas the pressure is still relatively high.

The apparatus 1 comprises a first container 4 and a second container 5. The first and second containers 4, 5 communicate with each other through a liquid communication line 6 and a vapour communication line 7. Under operating conditions as shown in Fig. 1 the containers 4, 5 are filled with water 8 via a filling valve 9 which is provided in the first container 4. It is noted that the filling valve 9 may also be provided in the second container 5. Due to the liquid communication line 6 the water level in the first and second containers 4, 5 is in equilibrium. The water level is below locations 10, 11 at the first and second containers 4, 5, respectively, where the vapour communication line 7 communicates with the first and second containers 4, 5, respectively. This means that the vapour communication line 7 is kept free from liquid water 8. The first container 4 is provided with a heater 12 which is located at a bottom of the first container 4. Under operating conditions the heater 12 heats the water 8 in the first container 4 up to its boiling temperature and steam will be formed above the water level. Further heating increases the steam pressure since the system in closed, i.e. if the filling valve 9 of the first container 4 is sealed the water 8 cannot leave the first and second containers 4, 5. At the same time, because of increased pressure, the water temperature in the first container 4 will exceed 100 ⁰C. Due to the vapour communication line 7 the steam will also increase the pressure above the water level in the second container 5. As a consequence, the water 8 in the second container 5 is also under pressure, but the water temperature in the second container 5 is still relatively low since water flow through the liquid communication line 6 will be minimal.

At a certain moment a tapping valve 13 can be opened in order to start a flow of water 8 to the brew chamber 2. When opening the tapping valve 13 the steam pressure above the water level in the first and second containers 4, 5 will press the hot water 8 through a first outlet 14 out of the first container 4 and the relatively cold water 8 through a second outlet 15 out of the second container 5. Both hot and cold water flows join in a mixing chamber 16, in which the heated water 8 and the relatively cold water 8 are mixed. Downstream of the mixing chamber 16 the mixed and ready-to-use water flows through a prepared liquid line 17 in this case. The tapping valve 13 is provided in the prepared liquid line 17. The tapping valve 13 may be a self-opening valve which opens and/or closes at a predetermined pressure level.

In the embodiment as shown in Fig. 1 the first and second outlets 14, 15 are disposed at bottom portions of the first and second containers 4, 5, respectively. This means that the first and second containers 4, 5 can easily be emptied entirely. Furthermore, the first and second containers 4, 5 have similar sizes and shapes, and are located next to each other at the same height level.

Figs. 2a and 2b illustrate two different conditions of the embodiment of the apparatus 1 of Fig. 1. Fig. 2a shows a condition in which the water level as indicated by a broken line 18 is just below the horizontally oriented vapour communication line 7, whereas Fig. 2b shows a condition in which the water level is considerably lower. In both conditions the prepared volume of beverage will be different, but the ratio of the hot and cold water 8 in the mixing chamber 16 will be maintained. The ratio of the hot and cold water 8 in the mixing chamber 16 can be modified by the dimensions of the first and second containers 4, 5. Several alternative embodiments are illustrated in Figs. 3a-3f. In the embodiment as shown in Fig. 3a the first and second containers 4, 5 are integrated in one housing, wherein the first and second containers 4, 5 are separated by an upwardly oriented wall 19, which prevents easy mixing of the water 8 in the first and second containers 4, 5. The vapour communication line 7 is formed by an opening between the wall 19 and an upper wall of the integrated first and second container 4, 5 at an upper portion thereof. The liquid communication line 6 is formed by an opening between the wall 19 and a bottom of the integrated first and second container 4, 5. The first and second outlets 14, 15 of the first and second containers 4, 5, respectively, are communicating with the liquid communication line 6. In fact, in this configuration the liquid communication line 6 also forms the mixing chamber 16. In the embodiment as shown in Fig. 3b the first container 4 surrounds the second container 5. The upwardly- oriented wall 19 may be cylindrically shaped and may have a rectangular or circular cross-section. Preferably, the wall 19 between the first and second containers 4, 5 is insulated to minimize heat transfer from the first container 4 to the second container 5. A more practical embodiment is shown in Fig. 4. The vapour communication line 7 and the locations 10, 11 where the first and second containers 4, 5 are in vapour communication with each other, as well as other elements as shown in Figs. 1-3 are also indicated in Fig. 4. The filling valve 9 is formed by a pad holder 2 in this embodiment. The heater 12 has a circular shape and is mounted at the bottom of the first container 4. The first outlet 14 of the first container 4 surrounds the second outlet 15 of the second container 5. The embodiments as shown in Figs. 3c and 3d have separated first and second containers 4, 5 which have different sizes. The mixing ratios of hot and cold water 8 can be influenced by applying different sizes. Due to these variations the final temperature of the mixed water can be affected. In the embodiments as shown in Figs. 3e and 3f the first and second containers 4, 5 have similar volumes but the width of the containers vary in opposite directions as seen in vertical direction. The advantage of the varying container shapes is that during the water supply period the temperature profile of the water downstream the mixing chamber can be influenced. It may be desired, for example, to supply a higher initial water temperature to compensate for heat losses in the apparatus downstream of the mixing chamber. After a first period the heat losses may decrease hence allowing a water supply of lower temperature. A further influencing parameter of the mixing ratio is the cross-sectional area of the first and second outlets 14, 15.

From the foregoing, it will be clear that the invention provides an apparatus for preparing a beverage which is able to prepare a liquid of stable temperature and elevated pressure.

The invention is not limited to the embodiments shown in the drawings and described hereinbefore, which may be varied in different manners within the scope of the claims and their technical equivalents.

Claims

1. An apparatus (1) for preparing a beverage, comprising a first container (4) and a second container (5) for containing a liquid (8), the first and second containers (4, 5) being in liquid communication with each other, a heater (12) for heating a liquid (8) in the first container (4), a mixing chamber (16) for mixing heated liquid (8) of the first container (4) and liquid (8) of the second container (5), a tapping valve (13) located downstream of the mixing chamber for building up a liquid pressure in the first and second containers (4, 5), and in the mixing chamber upon heating a liquid (8) in the first container (4) above its boiling temperature, characterized in that the first container (4) is in vapour communication with the second container (5), and the locations (10, 11) at the first and second containers (4, 5) where the first and second containers (4, 5) are in vapour communication with each other are disposed at a higher height level than those where the first and second containers (4, 5) are in liquid communication with each other, and wherein the first and second containers (4, 5) are provided with first and second outlets (14, 15), respectively, which are disposed at a lower height level than the locations (10, 11) at the first and second containers (4, 5) where the first and second containers (4, 5) are in vapour communication with each other, which first and second outlets (14, 15) are in liquid communication with the mixing chamber (16) .

2. An apparatus (1) according to claim 1, wherein the first and second outlets (14, 15) and/or the locations at the first and second containers where the first and second containers are in liquid communication with each other are disposed at bottom portions of the first and second containers (4, 5), respectively.

3. An apparatus (1) according to claim 1 or 2, wherein the shapes and dimensions of the first and second containers (4, 5) are substantially the same.

4. An apparatus (1) according to one of the preceding claims, wherein the first and second containers (4, 5) are cylindrically shaped.

5. An apparatus (1) according to one of the preceding claims, wherein the first and second containers (4, 5) are integrated in a housing and separated by a wall (19) within the housing.

6. An apparatus (1) according to one of the preceding claims, wherein the first and second containers (4, 5) are in vapour communication with each other via a vapour communication line (7) .

7. An apparatus (1) according to one of the preceding claims, wherein the first and second containers (4, 5) are in liquid communication with each other via a liquid communication line (6) .

8. An apparatus (1) according to claim 7, wherein the first and second outlets (14, 15), the liquid communication line (6) and the mixing chamber (16) are integrated.

9. An apparatus (1) according to one of the preceding claims, wherein the second container (5) at least partly surrounds the first container (4), or the first container (4) at least partly surrounds the second container (5) .