BREWING DEVICE FOR PREPARING A HOT BEVERAGE AND ASSOCIATED METHOD

Abstract

A brewing device for preparing a hot beverage includes: a hot water supply device with a hot water outlet; a brewing unit that receives hot water from the supply device and dispenses brewed hot beverage through a fluid outlet line into a hot beverage outlet; a hot water bypass line; a controllable hot water switching device temporarily connecting the bypass line to the hot water outlet, the hot water supplied into the bypass line being dispensable into the hot beverage outlet; and a control unit controlling the hot water switching device. The hot beverage outlet includes a hot beverage dispensing line, the fluid outlet line and the bypass line opening into the hot beverage dispensing line downstream of the brewing unit and the hot water switching device, respectively, to dispense by the hot beverage dispensing line the brewed hot beverage and the hot water supplied into the bypass line.

Claims

1. A brewing device (1) for preparing a hot beverage, in particular an automated coffee machine, wherein the brewing device (1) has the following: a hot water supply device (22) with an outlet (22A) for hot water; a brewing unit (31) for carrying out a brewing process for preparing a brewed hot beverage, which has a fluid outlet line (36) and is configured for receiving hot water from the hot water supply device (22) during the brewing process and for dispensing the brewed hot beverage through a fluid outlet line (36) into a hot beverage outlet (65); a hot water bypass line (40); a controllable hot water switching device (50, 50A) which is configured for temporarily connecting the hot water bypass line (40) to the outlet (22A) of the hot water supply device (22) so that hot water is enabled to be supplied from the hot water supply device into the hot water bypass line (40), wherein the hot water bypass line (40) extends in such a way that hot water supplied in the hot water bypass line (40) is enabled to be dispensed into the hot beverage outlet (65); a control unit (5) for controlling the hot water switching device (50, 50A), wherein the hot beverage outlet (65) comprises at least one hot beverage dispensing line (60), wherein the fluid outlet line (36) opens into the at least one hot beverage dispensing line (60) downstream of the brewing unit (31) such that the brewed hot beverage is enabled to be dispensed through the at least one hot beverage dispensing line (60) of the hot beverage outlet (65), and wherein the hot water bypass line (40) opens into the at least one hot beverage dispensing line (60) downstream of the hot water switching device (50, 50A), such that hot water is enabled to be dispensed through the at least one hot beverage dispensing line (60) of the hot beverage outlet (65).

2. The brewing device (1) according to claim 1, wherein the hot water supply device (22) is configured to supply hot water from a single hot water source.

3. The brewing device (1) according to claim 1, wherein the hot water switching device (50, 50A) is configured to be controlled by the control unit (5) in such a way that the hot water bypass line (40) is at least temporarily connected to the hot water supply device (22) during the brewing process.

4. The brewing device (1) according to claim 1, wherein the hot water supply device (22) is designed to dispense a predefined amount of hot water during the brewing process via the outlet (22A) of the hot water supply device (22); wherein the hot water switching device (50, 50A) is configured be controlled by the control unit (5) in such a way that the hot water bypass line (40) is temporarily connected to the hot water supply device (22) during the brewing process and a part of the predefined amount of hot water dispensed via the outlet (22A) of the hot water supply device (22) is dispensed through the at least one hot beverage dispensing line (60) of the hot beverage outlet (65), and wherein the brewing unit (31) has an inlet (31A) for receiving hot water, said inlet (31A) being connected to the outlet (22A) of the hot water supply device (22) via a fluid line (30) such that the other part of the predefined amount of hot water dispensed via the outlet (22A) of the hot water supply device (22) is enabled be supplied to the inlet (31A) of the brewing unit (31) during the brewing process.

5. The brewing device (1) according to claim 1, wherein the hot water switching device (50) is a valve, in particular a 2/2-way solenoid valve with one inlet, one outlet, a throughput position, in which the input is connected to the outlet, and an interrupted position, in which the inlet is not connected to the outlet, wherein the inlet of the valve is connected to the outlet (22A) of the hot water supply device (22), wherein the outlet of the valve is connected to the hot water bypass line (40), and wherein a fluid line (25) upstream of the inlet of the valve establishes a connection between the outlet (22A) of the hot water supply device (22) and an inlet (31A) of the brewing unit (31).

6. The brewing device (1) according to claim 1, wherein the hot water switching device (50A) is a valve, in particular a 3/2-way solenoid valve, with one inlet, one first outlet, one second outlet, a first position, in which the inlet is connected to the first outlet, and a second position, in which the inlet is connected to the second outlet, wherein the inlet of the valve is connected to the outlet (22A) of the hot water supply device (22), wherein the first outlet of the valve is connected to the hot water bypass line (40), and wherein the second outlet of the valve is connected to an inlet (31A) of the brewing unit (31).

7. The brewing device (1) according to claim 1, wherein the control unit (5) is configured to control the hot water switching device (50, 50A) during the brewing process in at least one time interval or in a plurality of time intervals in such way that each time interval comprises a first time period (t1), in which the hot water bypass line (40) is connected to the hot water supply device (22), and a second time period (t2), in which the hot water bypass line (40) is not connected to the hot water supply device (22).

8. The brewing device (1) according to claim 7, wherein the ratio of the first time period (t1) to the second time period (t2) is defined or is enabled to be defined depending on a type of hot beverage to be prepared.

9. The brewing device (1) according to claim 7, wherein the first time period (t1) of at least one of the intervals is shorter than the associated second time period (t2) of the respective interval.

10. The brewing device (1) according to claim 1, which has a volume measuring device (12) which is configured to measure a volume (V) of the fluid discharged into the hot beverage outlet (65) over time and to output the associated measured values to the control unit (5), wherein the control unit (5) is further configured to control the hot water switching device (50, 50A) depending on the measured values from the volume measuring device (12).

11. The brewing device (1) according to claim 10, wherein the hot water switching device (50, 50A) is configured to be controlled during the brewing process by the control unit (5) in such a way that the hot water switching device (50, 50A) alternatingly switches between a first position, in which the hot water bypass line (40) is not connected to the hot water supply device (22), and a second position, in which the hot water bypass line (40) is connected to the hot water supply device (22), if a measured value for the volume (V) of the fluid dispensed into the hot beverage outlet (65), determined by the volume measuring device (12), is greater than or equal to a first predefined volume (v1).

12. The brewing device (1) according to claim 11, wherein the control unit (5) is configured to end the control of the hot water switching device (50, 50A) if a measured value for the volume (V) of the fluid dispensed in the hot beverage outlet (65), determined by the volume measuring device (12), is greater than or equal to a second predefined volume (v2), wherein the second predefined volume (v2) is greater than the first predefined volume (v1).

13. The brewing device (1) according to claim 1, wherein the brewing device (1) is further configured to supply steam, in particular in the form of a steam surge, to the hot water bypass line (40).

14. A method for preparing a hot beverage, in particular a coffee beverage, in the brewing device (1) according to claim 1, wherein the method comprises: determining a type of hot beverage to be prepared; specifying, on the basis of the type of hot beverage to be prepared, at least one parameter for the control of the hot water switching device (50, 50A); and controlling, by means of the control unit (5), the hot water switching device (50, 50A) according to the at least one parameter during the preparation of the hot beverage.

15. The method according to claim 14, wherein the parameter comprises one or more of the following variables: volume (V) of the fluid dispenses into the hot beverage outlet (65); first time period (t1) of an interval, in which the hot water bypass line (40) is connected to the hot water supply device (22); second time period (t2) of an interval, in which the hot water bypass line (40) is not connected to the hot water supply device (22); ratio of the first time period (t1) to the second time period (t2); change of the ratio of the first time period (t1) to the second time period (t2) over time.

16. The method according to claim 14, wherein the method further comprises: after completion of the preparation of the hot beverage: supplying steam, in particular a steam surge, into the hot water bypass line (40).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Exemplary embodiments of the brewing device and the associated method will be subsequently explained in greater detail on the basis of the drawings. As shown in the figures:

[0044] FIG. 1 a schematic view of a brewing device according to one embodiment;

[0045] FIG. 2 a schematic view of a brewing device according to another embodiment;

[0046] FIG. 3 brewing parameters over time of a brewing process using a brewing device according to one embodiment; and

[0047] FIG. 4 schematic pressure conditions in a brewing chamber of a brewing unit of a brewing device according to one embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

[0048] FIG. 1 shows a brewing device 1 according to one embodiment in a schematic view. Brewing device 1 has a cold water tank 10. Departing from cold water tank 10, a first fluid line 11, into which a flowmeter 12 is inserted, supplies the cold water to an arrangement of a pump 15 and a choke valve 16, from where the cold water flows through a continuous-flow heater 20 into a second fluid line 25. The arrangement of pump 15, choke valve 16 and continuous-flow heater 20 forms a hot water supply device 22 according to the embodiment depicted, wherein hot water is available at its outlet 22A, which corresponds to the outlet of continuous-flow heater 20. Hot water supply device 22 therefore supplies hot water from a single hot water source.

[0049] The supplied water flows via a third fluid line 30 via a check valve 32 to inlet 31A of a brewing unit 31. A switch valve 33 is provided upstream of inlet 31A of brewing unit 31 and may selectively supply water to the inlet of brewing unit 31 or may discharge a residual fluid, which is created, for example, after the completion of a brewing process in a brewing chamber of brewing unit 31, out of the brewing chamber of brewing unit 31 into a residual fluid container 120 via a drainage line 37.

[0050] A switching valve 75 may be switched in such a way that a fluid (hot water or steam) may be selectively delivered from a fifth fluid line 70 connected to second fluid line 25 to a hot water outlet 90 (via a fluid line 81 connected to switching valve 75), to a milk frothing device 85 (via a fluid line 80 connected to switching valve 75), or to a condensation device 95 (via a fluid line 82 connected to switching valve 75). Condensed water may drain off from condensation device 95 through another fluid line 96.

[0051] A crema valve 35 is provided at an outlet of the brewing chamber of brewing unit 31 in order to control the dispensing of fluid from the brewing chamber into a fluid outlet line 36. The fluid from the brewing chamber, thus typically the prepared hot beverage, like a coffee beverage, flows through fluid outlet line 36 and a mixing device 55, to be described later, into a hot beverage dispensing line (e.g., a coffee dispensing line) 60, and from there to a coffee outlet 65, which forms a hot beverage outlet.

[0052] A beverage container 110 is placeable on a beverage container tray 11 underneath coffee outlet 65 in order to receive the prepared hot beverage.

[0053] A fourth fluid line 40, which forms a hot water bypass line, is provided downstream of second fluid line 25, thus of the outlet of the hot water supply device and downstream of a branch point, from which the third fluid line branches off to supply hot water to brewing unit 31. A controllable hot water switching device is inserted into fourth fluid line 40 and is a 2/2-way solenoid valve 50 in the embodiment according to FIG. 1. Thus, in the embodiment according to FIG. 1, the third fluid line is permanently connected to second fluid line 25.

[0054] Valve 50 is switchable between a throughput position and an interrupted position. The switching is carried out selectively during a brewing process by means of a suitable control unit 5. During the brewing process, the flow resistance at the inlet of brewing unit 31 is comparatively high. In the interrupted position of valve 50, which is shown in FIG. 1, the valve is not permeable. Thus, the hot water flows exclusively to inlet 31A of brewing unit 31. In contrast, in the throughput position and due to the large flow resistance, a large part of the hot water flows through valve 50 and farther via a choke valve 51 to mixing device 55.

[0055] Mixing device 55 comprises a mixing chamber (not shown in the figures), which is connected both to fluid outlet line 36 and also to fourth fluid line 40 in such a way that a fluid, which flows from brewing unit 31 via fluid outlet line 36 to mixing device 55, may be mixed in the mixing chamber of mixing device 55 with a fluid, which flows from valve 50 via fourth fluid line 40 to mixing device 55. An outlet of the mixing chamber of mixing device 55 opens into hot beverage dispensing line (coffee dispensing line) 60, so that a fluid arrives into the coffee outlet 65 from the mixing chamber of mixing device 55 via hot beverage dispensing line (coffee dispensing line) 60, wherein hot beverage dispensing line 60 in the present example is branched in coffee outlet 65 into two line sections and each of these two line sections has at its end an outlet opening 60A for dispensing a hot beverage (e.g., coffee).

[0056] By this meansdepending on the position of valve 50a part of the hot water may be guided past brewing unit 31, and a good quality of the dispensed hot beverage may be guaranteed even at large volumes.

[0057] FIG. 2 shows an alternative embodiment, wherein identical reference numerals indicate identical or similar parts as in FIG. 1, and the description thereof is omitted here.

[0058] In the embodiment according to FIG. 2, a valve 50A is provided instead of valve 50, and is designed as a 3/2-way solenoid valve and has one inlet and two outlets. The inlet of valve 50A is connected to second fluid line 25 and thus to outlet 22A of hot water supply device 22. The first outlet of valve 50A is connected downstream to fourth fluid line 40, which forms a hot water bypass line. The second outlet of valve 50A is connected to inlet 31A of brewing unit 31 via third fluid line 30. In the first position of valve 50A, the inlet of valve 50A is connected to the first outlet of valve 50A; correspondingly, in the second position of valve 50A, the inlet of valve 50A is connected to the second outlet of valve 50A. Valve 50A may thus switch a dispensing of the hot water to fourth fluid line 50 and to the inlet of brewing unit 31.

[0059] Thus, in the embodiment according to FIG. 2, in one of the two positions of valve 50A, third fluid line 30 for supplying hot water into brewing unit 31 is connected to second fluid line 25, thus to outlet 22A of hot water supply device 22, and fourth fluid line 40 is blocked downstream of valve 50A. In the second of the two positions of valve 50A, fourth fluid line 40 is connected to second fluid line 25, thus to outlet 22A of hot water supply device 22, and third fluid line 30 for supplying hot water into brewing unit 31 is blocked.

[0060] FIG. 3 shows different parameters of brewing device 1 over time during a brewing process.

[0061] In the upper part of FIG. 3, the operation of pump 15 is depicted with two states (switched on or switched off).

[0062] In the middle part of FIG. 3, the position of valve 50 is depicted from the embodiment according to FIG. 1; the valve position open thereby corresponds to a position in which hot water bypass line 40 is connected to hot water supply device 22, and the valve position closed corresponds to a position in which hot water bypass line 40 is not connected to hot water supply device 22.

[0063] In the bottom part of FIG. 3, the progression of the fluid volume V dispensed to the hot beverage outlet is depicted.

[0064] Initially, valve 50 is closed. Pump 15 is switched on and operates at a constant output, is switched off again after a specific time period, subsequently switched on again. In this pre-brewing process, the volume of the supplied brewing water increases linearly during the time that pump is switched on, i.e., brewing water is supplied to brewing unit 31 at a constant volume flow in order to wet the coffee powder in the brewing chamber of brewing unit 31. During the switched off time, the water supplied into brewing unit 31 may distributed in the coffee powder, and crema valve 35 of brewing unit 31 is closed, so that a coffee beverage is not yet dispensed during this time period.

[0065] Subsequently, pump 15 is operated again at a constant output in the switched on state up to the end of the brewing process. Volume V of the supplied brewing water again increases linearly until a volume v0 is reached and the brewing process ends.

[0066] Valve 50 is controlled depending on volume V. The valve is controlled in the embodiment by way of example in such a way that valve 50 is closed if the volume is less than a first threshold value v1. As soon as first threshold value v1 is reached, valve 50 is opened and hot water flows through fourth fluid line 40, past brewing unit 31, directly into coffee outlet 65.

[0067] Valve 50 is controlled in the example shown in intervals with one first time period t1 (valve opened) and one second time period t2 (valve closed) respectively, i.e. in a pulsed manner. The total number of time periods, in which valve 50 is open during first time period t1, may, for example, be determined at predefined parameters t1 and t2 depending on the volume of the supplied brewing water. Alternatively, valve 50 may be controlled as a function of volume V in such a way that it is opened or closed when volume V reaches certain predefined threshold values. In the example according to FIG. 3, valve 50 is opened, by way of example, when volume V reaches value v01, and subsequently closed again when volume V reaches value v02, and afterwards opened again when volume V reaches value v03. In the present example, it is assumed that the pump output of pump 15, and thus the volume flow of the water supplied by pump 15, is constant when pump 15 is switched on. In this case, the duration of time period t1 is proportional to the volume difference v02v01, and the duration of time period t2 is proportional to the volume difference v03v02.

[0068] In the present example, the time point, beginning at which valve 50 is held constantly closed up to the end of the brewing process, is determined as follows. A second threshold value v2 is predefined for volume V. As soon as volume V reaches threshold value v2, then it is checked whether valve 50 is already open. If valve 50 is already open (not shown in FIG. 3), then valve 50 remains open up to the end of the most recently carried out pulsed control of the duration of first time period t1; subsequently, valve 50 is closed and remains closed up to the end of the brewing process.

[0069] When volume V reaches value v0, the end of the brewing process is reached, and pump 15 is switched off.

[0070] In the example according to FIG. 3, valve 50 is repeatedly controlled through multiple pulses of period t1 and correspondingly periodically recurringly opened and closed. Alternatively, it is also conceivable that valve 50 is only to be opened during one single time interval, with a time period t1, which corresponds to a fraction of the duration of a coffee draw-off, during the course of a brewing process, and is otherwise kept closed. This single opening of valve 50 may be carried out at any time point during the brewing process, e.g., at the beginning of the respective brewing process or at the end of the respective brewing process or at another time point between the beginning and the end of the respective brewing process.

[0071] In the case of the embodiment according to FIG. 2, the control of pump 15 and valve 50A is carried out analogously to the depiction according to FIG. 3. Valve 50A according to FIG. 2 may be controlled in a pulsing way with the same pulse sequence as valve 50 in FIG. 3. If valve 50A is controlled in a pulsing way with pulses of period t1 and intervals of period t2 between two consecutive pulses, then valve 50A is brought to periodic alternation in two different states, in which third fluid line 30 for supplying hot water into brewing unit 31 is alternatingly connected to second fluid line 25 and fourth fluid line 40 is blocked downstream of valve 50A, or fourth fluid line 40 is connected to second fluid line 25 and third fluid line 30 for supplying hot water into brewing unit 31 is blocked.

[0072] Correspondingly, the hot water supplied through second fluid line 25 during the pulsed control of valve 50A flows alternatingly through third fluid line 30 or through fourth fluid line 40.

[0073] FIG. 4 shows the pressure of the brewing water in the brewing chamber of brewing unit 31 as a function of time t during a coffee draw-off following the pre-brewing, with a continuously operating pump 15 and pulsed control of valve or of valve 50A with pulses of period t1 and time interval t2 between two consecutive pulses.

[0074] Pump 15 operates during the coffee draw-off at maximum output and is typically designed to generate a pressure of typically 15 bar.

[0075] When fourth fluid line 40 is connected to hot water supply device 22, the pressure of the brewing water in the brewing chamber of brewing unit 31 drops. The size of the pressure drop during one pulse of time period t1 depends on the size of t1, thus the time frame, during which fourth fluid line is respectively connected to the hot water supply device. If t1 is large (e.g., greater than 1 second), then the pressure of the brewing water in the brewing chamber may drop to approximately 0 bar, when valve 50 or valve 50A releases fluid line 40.