BACKGROUND

1. Field of the Disclosure

The disclosure relates to a method for the dispensing of a hot beverage and a device for implementing the method

2. Discussion of the Background Art

A number of different parameters are taken into consideration in the brewing of hot beverages in modern beverage vending machines. In the preparation of coffee, for example, the degrees of roasting and grinding of the coffee beans, the ratio of coffee powder to hot water, or the duration of the brewing process are taken into account for this purpose. Also, parameters such as the temperature of the hot water, the pressure inside the brewing chamber, or the type of filter are selected in a targeted manner, based on their effects on the taste of a finished coffee drink.

In this case, the concentration of the coffee solution is decisive for the taste of a coffee drink. The latter corresponds to the amount of dissolved coffee in relation to the hot wafer and determines the strength of a coffee. The concentration of a coffee depends on how much coffee powder is used for the brewing process and what proportion of the coffee powder is dissolved in the hot water. The proportion by weight of the coffee powder, which is used for the brewing process and which is dissolved in water, is designated in this connection as extraction and increases with increasing duration of the brewing process. With increasing duration of the brewing process, however, increasingly more undesired bitter substances are also leached out of the coffee powder and transferred to the liquid. In order to increase the concentration of a coffee drink, accordingly, on the one hand, the quantity of coffee powder being brewed, and, on the other hand, the duration of the brewing process can be increased. In order to avoid an increased quantity of bitter substances in the finished coffee drink due to a long brewing time, the quantity of coffee powder is usually increased instead of the brewing time, so as to obtain the desired concentration. The optimal concentration for black coffee, for example, lies between 1.30 wt.% and 1.55 wt.%, and the optimal extraction lies between 18 wt.% and 22 wt.%, in each case referred to the total weight of the finished hot beverage.

The previous statements apply in principle both to espresso as well as to corresponding application also for tea, which is brewed in a hot beverage vending machine.

Known from EP 1 005821 B1 is a brewing device, which comprises a brewing unit with a brewing chamber for the preparation of coffee or tea. Optimal values for the concentration or extraction cannot be obtained with such a brewing unit, however, since a sedimentation of the brewing material takes place inside the brewing chamber during the brewing process. As a consequence of this sedimentation, the brewing material only comes into contact with a small portion of the hot water that is introduced. In this case, a high extraction results in this comparatively small contact volume, which leads to the circumstance that the passage of the aromas from the brewing material into the hot water is adversely influenced by the small concentration gradient between the particles of the brewing material and the hot water surrounding them. The document provides no indication of how to improve the extraction of the aromatic substances from the brewing material into the hot water.

Accordingly, the object of the present disclosure is to create a method for the preparation of a hot beverage, in particular of coffee or tea, with which the extraction of the flavors contained in the brewing material into the hot water can be improved during the brewing process.

Another object of the disclosure is to create a device for implementing the method according to the disclosure.

SUMMARY

According to the disclosure, a device for implementing the method according to the disclosure, which is designated also in the following as a beverage vending machine, comprises a hot water generating system for the generation of hot water and a brewing chamber, as is described in detail, e.g., in the above-mentioned EP 1 005 821 B1. For brewing the hot beverage, the brewing chamber is filled with the brewing material, i.e. , coffee powder or espresso powder or tea, and, after this, it is loaded with hot water via a hot water inlet. After the brewing process, the hot beverage is delivered from the brewing chamber into a vessel via a hot beverage outlet and a drain line connected therewith. The method is characterized in that the hot beverage outlet is loaded with compressed gas from a compressed gas source during a brewing process according to the disclosure.

As the Applicant has found, the suspension of hot water and brewing material is intermixed due to the compressed gas introduced into the brewing chamber and is homogenized continually thereby during the brewing process. A sedimentation of the brewing material on the bottom of the brewing chamber is effectively prevented thereby, and the brewing material comes into contact with a larger quantity of hot water in an advantageous way over the entire duration of the brewing process. The contact volume increased thereby leads to an enhanced extraction of aromatic substances with the quantity of brewing material remaining the same and with the same brewing time. Consequently, by the method according to the disclosure, the quantity of required brewing material can be reduced in an advantageous way, in order to obtain the same concentration of all dissolved aromatic substances in the finished hot beverage without increasing the brewing time and thereby also increasing the quantity of bitter substances released in a disadvantageous way. Furthermore, due to the compressed gas, which flows through the hot beverage outlet into the brewing chamber, a dogging of the brewing filter found on the side of the brewing chamber in front of the hot beverage outlet is prevented, and in this way the filter can be regenerated.

In an advantageous embodiment of the method, it is provided that the duration and strength of loading the brewing chamber with compressed gas, i.e the time course of the volumetric flow of the compressed gas introduced into the brewing chamber or the quantity of compressed gas introduced over the entire brewing process, are adjustable. An individual adaptation of the concentration of the finished hot beverage can be achieved thereby each time, depending on what the user wants. In addition, the compressed gas can be introduced into the brewing chamber with an adjustable delay after beginning the brewing process, whereupon the advantage results that the brewing material, e.g., coffee powder, floating directly on the surface is already wetted with water after the introduction of the hot water, and due to the rising compressed gas, is not transported to the upper part of the inner wall of the brewing chamber, does not remain attached thereto, and thus does not lead to undesired deposits. In the case of a brewing process that lasts, e.g., for 15 seconds, this delay can amount to two seconds, for example.

In addition, for emptying the brewing chamber after a brewing process, it can be provided that the brewing chamber is loaded with compressed gas from the same compressed gas source or from another compressed gas source byway of the hot water inlet. Due to the compressed gas, which flows through the hot water inlet into the brewing chamber for this purpose, the hot beverage containing the aromas of the brewing material dissolved therein is pressed through the brewing filter by the prevailing overpressure, the filter sealing the hot beverage outlet like a sieve, preventing a discharging of the spent brewing material from the hot beverage outlet. The latter spent material is removed from the cylinder-shaped brewing chamber after this by raising the top and/or bottom part of this brewing chamber, as is described, for example, in the abovementioned EP 1 005 821 B1.

Although ambient air from the surroundings, which is aspirated and compressed, in particular by an electrically driven compressor, is preferably used as the compressed gas, alternatively an inert gas, in particular nitrogen, can be used as the compressed gas, which loads the brewing chamber during the brewing process in order to homogenize the hot water/brewing material mixture, and/or is used for expelling the finished hot beverage after the termination of a brewing process. The taste of the hot beverage can thereby be additionally improved once more during the brewing process as a consequence of the missing oxidative effect of the air that would otherwise be present in the brewing chamber.

According to another concept lying at the basis of the disclosure, a device for implementing the process described above comprises the already mentioned brewing chamber and the hot water generating system, which is fluidically connected to the hot water inlet preferably arranged on the top of the brewing chamber via a line connection. A hot beverage outlet is arranged on the bottom of the brewing chamber for the dispensing of a hot beverage brewed in the brewing chamber.

The hot water inlet is fluidically connected to the hot water generating system by way of at least one inlet valve, and the hot beverage outlet is connected to a drain line at least by way of a valve on the outlet side, and the hot beverage is dispensed via this drain line into a vessel, in particular a cup, after a brewing process.

The device is characterized in that the hot beverage outlet is fluidicaily connected to a branch line and a switchable additional valve on the outlet side, by way of which it can be loaded with compressed gas from a compressed gas source during a brewing process.

The compressed gas source arranged in the device can be, as mentioned previously, an electrical pump for producing compressed air or also a compressed gas tank. As a compressed gas tank, in particular, a compressed gas cylinder can be used, which can be fluidicaily connected to the hot water outlet via an electrically actuatabie valve, in particular a shut off valve, which is controlled by means of an electronic control device.

In the preferred embodiment of the device, the compressed gas provided by the compressed gas source is compressed air, although alternatively, an inert gas, preferably nitrogen, can be employed. The use of a compressed gas tank as a compressed gas source has the advantage that different kinds of compressed gases can be used, e.g., also mixtures of different gases, and the installation of a pump is eliminated. In contrast to this, the use of a pump or a compressor as a compressed gas source has the advantage that it does not need to be constantly changed or filled again, and in the case of compressed air, can be operated essentially in a more cost-effective manner.

According to another concept lying at the basis of the disclosure, in addition, it may be provided that the hot beverage outlet is connected to the drain line for the hot beverage by way of a flexible, deformable tubing, e.g., a silicone tubing. This opens up the possibility that at least one valve on the outlet side is executed as a pinch valve, which has an eiectromechanically actuated slider or pinch piece, by means of which the tubing can be pressed together for the closure thereof. The use of a pinch valve has the advantage that a complicated cleaning of the valve is eliminated, and instead of this, the flexible, deformable tubing can be changed in a simple and cost-effective way, as soon as it becomes plugged up by contaminants or becomes brittle due to aging, or has another defect.

According to another concept lying at the basis of the disclosure, the at least one valve on the outlet side can alternatively also be designed as a known 3/2-way valve.

In addition, in a particularly cost-effective embodiment of the disclosure to be fabricated, it can be provided that only a single compressed gas source is provided, which is connected to the hot water inlet of the brewing chamber via an electrically switchable shut-off valve and simultaneously to the branch line via a spring-loaded non-return valve. In this case, the branch line comprises a flexible, deformable tubing, which can be pressed together by the additional valve on the outlet side designed as an electrically switchable pinch valve, in order to seal the tubing.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be described below with reference to the drawings on the basis of a preferred embodiment of the disclosure.

In the drawings:

Fig. 1 shows a schematic representation of a preferred embodiment of the device according to the disclosure, which comprises two compressed gas sources;

Fig. 2 shows a schematic representation of another embodiment of the device according to the disclosure, which comprises only one compressed gas source; Fig. 2a shows a schematic representation of another embodiment of the disclosure, in which, instead of a chain valve utilized in Fig. 2, a spring-loaded non-return valve is employed;

Fig. 3 shows a schematic representation of the embodiment shown in

Figure 1 , in which the shut-off valve is replaced by a non-return valve;

Fig. 4 shows a schematic representation of the embodiment shown in

Figure 2, in which, instead of a chain valve, a 3/2-way valve in combination with a non-return valve is employed;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As is shown in Figures 1 and 2, a device 1 for the dispensing of a hot beverage comprises a hot water generating system 2 for the generation of hot water having a temperature of, e.g., 80 °C to 100 °C, and a brewing chamber 4. The brewing chamber has a hot water inlet 5 that can be fluidically connected to the hot water generating system 2 for the supply of hot water, as well as a hot beverage outlet 8 arranged on the bottom of the brewing chamber 4; the hot beverage brewed in the brewing chamber 4 can be dispensed from the outlet via a drain line 9.

Inside the brewing chamber 4 is found a brewing filter 7, which prevents the large particles of brewing material 6, e.g., coffee powders, from entering into the hot beverage outlet 8 and beyond this into the drain line 9 during the brewing process. As is shown in Fig. 1 , for the embodiment of the disclosure shown therein, the hot water inlet 5 is fluidically connected to the hot water generating system 2 via a T-shaped connection piece 17 and a first electrically switchable valve 11 on the inlet side. The hot beverage outlet 8, in contrast to this, is connected to the drain line 9 for the dispensing of the freshly brewed hot beverage into a vessel 40 via a Y-shaped connection piece 19 and a first electrically switchable pinch valve 13 on the outlet side. By means of a line 10 which branches off via the Y-shaped connection piece 19 and springs from the latter, the hot beverage outlet 8 is connected to a compressed gas source 20 via an intermediately connected second electrically switchable shut-off valve 14 on the outlet side, this valve 14 being connected in the same way as are also the rest of the valves 11 , 12 and 13 to an electronic control device 30, which controls them.

In the preferred embodiment shown in Figure 1 , in addition, the device 1 for the dispensing of a hot beverage comprises a second compressed gas source 21 , which is connected to the T-shaped connection piece 17 by way of a second electrically switchable valve 12 on the inlet side, and can be utilized for the purpose of loading the brewing chamber 4 with compressed gas via the hot water inlet 5 toward the end of the brewing process.

Alternatively to the embodiment shown in Fig. 1 , in which two compressed air sources 20, 21 are used, the electrically switchable shut-off valve 14 employed therein, as shown in Figure 3, can be replaced by a non-return valve 16 arranged in the flow direction of the compressed gas from the compressed gas source 20, non-return or check valve 16 preventing a back flooding of the compressed gas source and, moreover, in an advantageous manner, it does not need to be actuated electrically.

Figure 2 shows another embodiment of the device 1 according to the disclosure for the dispensing of a hot beverage, which is characterized in that one and the same compressed gas source 20 can be used for the purpose of loading the brewing chamber 4 with compressed gas both on the inlet side as well as on the outlet side. For this purpose, the compressed gas source 20 can be connected to the hot beverage outlet 8 of the brewing chamber 4 via an electrically switchable first shut-off valve 15a during the brewing process by way of a compressed air line 10a, the first electrically switchable pinch valve 13 on the outlet side and the Y-shaped connection piece 19 on the outlet side. In this case, the press piece (not shown in more detail) of the pinch valve 13, which can travel back and forth by means of the electronic control device 30 shuts off the elastically deformable drain line 9 by pressing it together to an extent such that no compressed air can escape via the drain line 9, so that the air is pressed through the brewing filter 7 in the form of rising air bubbles into the brewing chamber 4 when the compressed air source 20 is activated and the first shut-off valve 15a is opened.

In order expel the freshly brewed hot beverage from the brewing chamber 4 after a brewing process, the first shut-off valve 15a is closed and a second shut-off valve 15b that can be actuated by the electronic control device 30 is opened, this latter valve preferably being disposed together with the first biockabie shut-off valve 15a in a chain valve, or a chain of valves 15. The compressed air is introduced into the brewing chamber 4 in this case with a dosed first valve 11 on the inlet side, i.e. , with a closed-off hot water supply from the hot water generating system 2, by way of the T-shaped connection piece 17 and the hot water inlet 5 connecting thereto, so that the brewing chamber is loaded with a pressure of, e.g., 1 bar via the compressed air source 20. Simultaneously or a short time later, the pinch valve 13 is actuated and the connection line 10a is shut off by pressing together the elastically deformable tubing segment belonging thereto of the connection line 10a and freeing up the drain line 9, whereupon the freshly brewed hot beverage can flow through the brewing filter 7 into the vessel 40 by way of the hot beverage outlet 8 and the drain line 9.

In order to clean the brewing chamber 4 following the dispensing of the hot beverage and to discard the used brewing material, the second shut-off valve 15b can be closed, the drain line 9 can be opened by means of the pinch valve 13, and, via the first valve 11 , hot water can be introduced into the brewing chamber 4, said hot water removing any residues of the hot beverage that adhere to the brewing chamber 4.

Alternatively to the described embodiment comprising a chain valve 15, this mode of operation can also be realized by a standard, closed 3/2 way valve that is disposed in the direction of flow of the compressed gas from the compressed gas source 20. In this embodiment, which is shown in Figure 4, the line 10a is also closed by means of a non-return valve 16, which is preferably spring-loaded, in order to prevent the possibility of pressing the brewing material into the compressed gas source 20.

In order to still further reduce the device cost, in addition, it can be provided, instead of the first shut-off valve 15a, to insert a spring-loaded non-return valve 16 into the line 10a, and to connect this line directly to the one compressed gas source 20, as this is shown in Fig. 2a.

The single compressed gas source 20 in this case is connected to the hot water inlet 5 via a single shut-off valve 15b, and to the line 10a via the spring- loaded non-return valve 16; this line 10a can be shut off by the pinch valve 13 when, in conclusion to a brewing process, the hot beverage is expelled from the brewing chamber 4 by the compressed gas from the compressed gas source 20 via the drain line 9 after opening the single shut-off valve 15b.

List of reference numerals

Device according to the disclosure

2 Hot water generating system

4 Brewing chamber

5 Hot water inlet of the brewing chamber

6 Brewing material

7 Brewing filter 8 Hot beverage outlet of the brewing chamber

9 Drain line

10 Line between compressed gas source and Y-shaped connection piece

10a Line between compressed gas source and Y-shaped connection piece

1 1 First electrically switchable valve on the inlet side

12 Second electrically switchable valve on the inlet side

13 First electrically switchable pinch valve on the outlet side

14 Second electrically switchable valve on the outlet side

15 Electrically switchable chain valve

15a Electrically switchable first shut-off valve of the chain valve

15b Electrically switchable second shut-off valve of the chain valve

16 Non-return or check valve

17 T-shaped connection piece

18 Electrically switchable 3/2-way valve

19 Y-shaped connection piece

20 First compressed gas source

21 Second compressed gas source

30 Electronic control device

40 Vessel