Beverage preparation equipment and operating procedures

Abstract

Beverage preparation device, in particular coffee machine (1A, 1B, 1C) with a milk frothing device (2) which has a nozzle device (3) for heating and / or frothing milk (9) by means of steam (5), wherein a vacuum can be generated with the nozzle device (3) when steam is applied, with which milk can be drawn from a milk reservoir (11) via a suction line (10) connected to the nozzle device (3) in a fluid-conducting manner, wherein the milk frothing device (2) further comprises a milk outlet channel (7) arranged downstream of the nozzle device (3) with an outlet opening (8) for milk foam, wherein the suction line (10) can be supplied with a rinsing medium and is connected in a fluid-conducting manner to a discharge line (14) for discharging rinsing medium from the suction line (10),characterized by a valve arrangement (16) comprising a first valve (17) arranged in the suction line (10) between the milk frothing device (2) and the milk reservoir (11), and a second valve (18) arranged in the discharge line (14), wherein when milk is drawn in, the first valve (17) is in an open position and the second valve (18) is in a closed position, and wherein when the suction line (10) is flushed with flushing medium, the first valve (17) is in a closed position and the second valve (18) is in an open position, wherein the valves (17, 18) of the valve arrangement (16) are pressure-dependent, self-switching check valves.

Description

[0001] The present invention relates to a beverage preparation device, in particular a coffee machine with a milk frothing unit, which has a nozzle for heating and / or frothing milk using steam, wherein a vacuum can be generated by the nozzle when steam is applied, with which milk can be drawn from a milk reservoir via a suction line connected to the nozzle by a fluid. The milk frothing unit further comprises a milk outlet channel arranged downstream of the nozzle with an outlet opening for milk foam, wherein the suction line can be supplied with a rinsing medium and is connected to a discharge line for removing the rinsing medium from the suction line by a fluid. The invention further relates to an operating method for operating a beverage preparation device according to any one of claims 1 to 8.

[0002] In beverage preparation appliances, especially coffee machines, with a device for heating and / or frothing milk, the components that come into contact with milk must be rinsed periodically after dispensing a beverage containing milk to prevent milk residue from remaining in the system for an extended period. Milk spoils quickly, especially if refrigeration is not maintained.

[0003] The milk frothing devices of beverage preparation devices known from the prior art are usually cleaned by passing, for example, steam or hot water through the milk frothing device to be cleaned.

[0004] A separate cleaning of the milk intake tube (suction line), which also contains milk residue, is usually carried out by removing it and rinsing it by hand under running water.

[0005] In other devices known from the prior art, the milk suction hose is cleaned by removing one end of this hose from the milk container, temporarily immersing it in a container with cleaning fluid, and then drawing milk from the beverage preparation machine, whereby the cleaning fluid (instead of milk) is then drawn through the milk suction hose and it is thereby cleaned or rinsed.

[0006] However, the cleaning methods mentioned above are relatively cumbersome.

[0007] EP 2 807 964 A1 describes a beverage preparation device with the features of the preamble of claim 1. In this device, the milk suction line is cleaned by disconnecting, prior to the cleaning process, a suction line leading into a milk reservoir from a milk supply line through which milk is fed into a milk frothing device during beverage preparation. The milk supply line is then connected via a connecting element to a rinsing line through which used rinsing medium can be discharged. The milk supply line is then supplied with rinsing medium, which flows from the milk supply line through the connecting element into the rinsing line and is finally discharged to the outside. This procedure for cleaning such a device is also cumbersome.

[0008] The present invention is based on the objective of providing a beverage preparation device whose milk-carrying components, in particular its milk suction line, can be easily rinsed with a rinsing medium.

[0009] This problem is solved according to the invention by a beverage preparation device of the type mentioned at the outset, which is characterized by a valve arrangement with a first valve arranged in the suction line between the milk frothing device and the milk reservoir and a second valve arranged in the discharge line, wherein when milk is drawn in the suction line the first valve is in an open position and the second valve is in a closed position, and wherein when the suction line is rinsed with rinsing medium the first valve is in a closed position and the second valve is in an open position, wherein the valves of the valve arrangement are pressure-dependent, self-switching check valves.

[0010] One of the advantages of the device according to the invention is that no manual intervention by the user, such as changing the connection of the suction line, is required during a rinsing process. This ensures a high level of user-friendliness. Hygiene is improved through the possibility of automatic cleaning cycles. The valve arrangement of the device according to the invention prevents milk from flowing into the discharge line during a milk intake process, in which milk is fed from the milk reservoir via the suction line into the milk frothing device, by blocking the milk flow with the second valve. During a rinsing process, on the other hand, it prevents rinsing fluid from entering the milk reservoir.

[0011] Preferably, a feed line opens into the suction line, through which air can be supplied to the milk during a frothing process and / or through which rinsing medium can be supplied to the suction line. This rinsing medium can then flow directly from the suction line into the nozzle assembly of the milk frothing device and / or via the suction line into the discharge line. Such a feed line has the advantage that the rinsing medium does not need to be introduced via the nozzle assembly of the milk frothing device, but can be added separately to the suction line. This means that the nozzle assembly does not need to be disconnected from any heating element present during a rinsing process in order to introduce rinsing medium into the suction line.

[0012] Advantageously, the valves in the valve arrangement are spring-loaded plunger valves, diaphragm valves, slide valves, and / or butterfly valves. Such valves ensure the safe operation of the beverage preparation device according to the invention. User errors, for example, due to incorrectly switched valves, are eliminated by the aforementioned valves.

[0013] In one embodiment of the device according to the invention, an outlet end of the discharge line is arranged adjacent to the outlet opening and preferably above a drip tray, so that rinsing medium can exit next to the outlet opening, in particular parallel to a milk discharge direction. In this embodiment, used rinsing medium is therefore no longer returned to the milk frothing device, but is disposed of before reaching the milk frothing device.

[0014] In another embodiment of the beverage preparation device according to the invention, an outlet end of the discharge line opens upstream of the outlet opening, in particular via a connecting channel into the milk outlet channel, so that rinsing medium can exit through the outlet opening. This also flushes the milk outlet channel with rinsing medium. In this embodiment, the valve arrangement can be connected to the milk frothing device via a double hose, which includes the suction line and the discharge line. However, the connection can also be made via two separate hoses / lines.

[0015] In a further embodiment of the beverage preparation device according to the invention, the outlet end of the discharge line opens, in particular via a connecting channel, into an annular chamber surrounding the outlet opening of the milk outlet channel. The advantage of this embodiment is, in particular, that the rinsing medium is also used to rinse the milk outlet channel and remove any milk residue. This annular chamber is generally designed around the milk outlet channel in such a way that cleaning of the entire circumference of the milk outlet channel is possible.

[0016] The valve assembly can be located inside the milk reservoir, inside a lid of the milk reservoir, or outside the milk reservoir.

[0017] Preferably, the discharge line opens into the intake line in the area of ​​the valve assembly, in a section between the milk frothing device and the first valve. This ensures perfect interaction of the valves in the valve assembly.

[0018] The present invention further relates to a method for operating a beverage preparation device according to one of claims 1 to 8, wherein, in order to produce a beverage, in particular a coffee specialty containing milk foam, steam is first introduced into a nozzle assembly of a milk frothing device, whereby a vacuum is generated in the nozzle assembly, with which milk is drawn from a milk reservoir connected to the nozzle assembly via a fluid-conducting suction line and directed into the nozzle assembly of the milk frothing device, frothed there and finally discharged via an outlet.wherein, during the beverage production process, a first valve of a valve arrangement located in the suction line between the milk frothing device and the milk reservoir is in an open position, and a second valve of the valve arrangement located in a discharge line connected to the suction line in a fluid-conducting manner is in a closed position, and wherein, for a cleaning process, the first valve of the valve arrangement is moved to a closed position and the second valve is moved to an open position, and the suction line is supplied with rinsing medium for cleaning.

[0019] Advantageously, the first and second valves of the valve arrangement are electronically controllable, in particular by means of a push button. This results in extremely simple and safe operation of the beverage preparation device according to the invention, both during the beverage production process and during the cleaning process.

[0020] Further features of the invention will become apparent from the following description of preferred embodiments of the invention in conjunction with the drawings and the dependent claims. The individual features can be implemented individually or in combination with one another.

[0021] The drawings show: Fig. 1: a schematic representation of a first embodiment of the beverage preparation device according to the invention; Fig. 2: a second embodiment of the beverage preparation device according to the invention; Fig. 3: a third embodiment of the beverage preparation device according to the invention; Fig. 4a-4c: schematic representations of possible arrangements of the valve arrangement of the beverage preparation device according to the invention on or in a milk container.

[0022] In the figures, identical elements and elements with the same function are marked with the same reference symbols.

[0023] Fig. Figure 1 shows in its upper half a schematic representation of a beverage preparation device according to the invention in the form of a coffee machine 1A with a device 2 for producing milk foam, hereinafter referred to as the milk frothing device. The milk frothing device 2 is shown here as being permanently attached to the coffee machine 1. However, it is also conceivable that the milk frothing device could be arranged to be detachable from the coffee machine.

[0024] The milk frothing device 2 comprises a nozzle assembly 3 for frothing milk using steam 5. The nozzle assembly 3 includes a drive nozzle (not shown here) and a vacuum chamber 4. The vacuum chamber 4 has a tapered outlet 6. This outlet 6 leads into a conically shaped milk outlet channel 7, which has an outlet opening 8 at its lower end through which milk 9 can flow out for further use.

[0025] The coffee machine 1 further comprises a milk suction line 10, which is fluidly connected at one end to a milk container 11. At its opposite end, the milk suction line 10 opens into a milk supply line 12 of the milk frothing device 2. The milk supply line 12 opens into the vacuum chamber 4 via a tapered throttle end 13.

[0026] A supply line 19 for supplying rinsing medium 24 and / or air into the milk supply line 12 opens into the milk supply line 12.

[0027] The milk intake line 10 is fluid-conducting and connected to a discharge line 14 for the removal of rinsing medium 24 from the milk intake line 10. Starting from the milk intake line 10, the discharge line 14 runs back towards the milk frothing unit 2, where it finally empties into a rinsing medium drain 15. The rinsing medium drain 15 then empties into the milk outlet channel 7.

[0028] The coffee machine 1 further comprises a valve arrangement 16 with a first valve 17 arranged in the milk intake line 10 between the milk frothing device 2 and the milk container 11, and a second valve 18 arranged in the discharge line 14. The valves 17 and 18 are self-sealing check valves. The discharge line 14 branches off from the milk intake line 10 in the area of ​​the valve arrangement 16 in a section between the milk frothing device 2 and the first valve 17.

[0029] The coffee machine 1 according to the invention can now be used to prepare a coffee specialty with milk foam or to carry out a cleaning process of the milk-carrying lines. The preparation of a beverage with milk foam is accomplished as follows: First, steam 5 is introduced into the vacuum chamber 4 through a drive nozzle (not shown). The flow of this steam 5, accelerated by the drive nozzle, through the vacuum chamber 4 creates a vacuum. This vacuum draws milk 9 through the milk suction line 10, which is rigid and an integral part of the device 1. The milk suction line 10 is in open connection with the milk supply line 12 and thus also with the vacuum chamber 4. At its other end, the milk suction line 10 is in fluid-conducting connection with the milk container 11. Because the first valve 17 of the valve assembly 16 is in an open position during this suction process, milk can flow unhindered from the milk container 11 through the milk suction line 10 into the milk supply line 12 and then through the throttle end 13 into the vacuum chamber 4.The fact that the second valve 18 is closed during this suction process prevents milk from flowing into the discharge line 14.

[0030] Air is introduced into the milk flow via the feed line 19, which leads into the milk suction line 10, and is swirled with the milk 9 in the vacuum chamber 4 to create milk foam. After frothing, the water vapor-milk-air mixture leaves the vacuum chamber 4 via the tapered outlet 6 of the vacuum chamber 4 into the milk outlet channel 7 and finally via the outlet opening 8 towards a drinking vessel.

[0031] Following a beverage production process, a cleaning process can then be carried out as follows: After the beverage preparation process, valves 17 and 18 are switched, i.e., valve 17 is moved from an open position to a closed position, and valve 18 from a closed position to an open position. Rinsing medium 24 is then introduced into the milk supply line 12 via the supply line 19. From there, the rinsing medium flows into the milk intake line 10. From the milk intake line 10, the rinsing medium flows into the discharge line 14, which is in open connection with the milk intake line 10. Because valve 17 is closed during the rinsing process, rinsing medium 24 cannot flow from the milk intake line 10 into the milk container 11. Since valve 18 is in an open position during the rinsing process, the rinsing medium 24 can flow from the discharge line 14 into the rinsing medium outlet 15 of the milk frothing unit 2.From the rinsing medium outlet 15, the rinsing medium finally flows into the milk outlet channel 7 and out of the milk frothing device via the outlet opening 8, where it is usually collected by a drip tray 21. In the case of... Fig. In the coffee machine 1 shown, the rinsing medium 24 flows through the milk intake line 10, the milk supply line 12 and the outlet channel 7, in addition to the milk intake line 10.

[0032] After the cleaning process and before the next beverage preparation process, valves 17 and 18 are reset accordingly, so that valve 17 is in an open position and valve 18 is in a closed position. Valves 17 and 18 are controlled electronically by simply pushing a button.

[0033] In the lower half of the Fig. Figure 1 schematically shows the milk or rinsing media flow in the valve arrangement 16.

[0034] Fig. Figure 2 schematically shows another embodiment of the beverage preparation device according to the invention in the form of a coffee machine 1B. The coffee machine 1B differs from the one shown in Figure 2. Fig. The coffee machine 1A shown in Figure 1 differs only in that the milk frothing device 2 does not have a rinsing medium drain, but rather the drain line 14 terminates blindly above a drip tray 21, parallel to the milk outlet channel 7. In this embodiment, the outlet end 20 of the drain line 14 is thus arranged adjacent to the milk outlet opening 8 above a drip tray 21, so that rinsing medium 24 can exit next to the milk outlet opening 8, parallel to a milk discharge direction.

[0035] Fig. Figure 3 shows the milk frothing device 2 of a further embodiment of a beverage preparation device according to the invention in the form of a coffee machine 1C. This embodiment differs from the coffee machine 1A of the Fig. 1. The difference lies solely in the fact that the milk supply line 12 does not open into the milk outlet channel 7, but rather into an annular channel 22 surrounding the milk outlet channel 7. In this embodiment, the rinsing medium 24 is additionally used to rinse the milk outlet channel 7, particularly in the area of ​​the outlet opening 8, and to remove any milk residue. The annular channel 22 is designed such that cleaning is possible along the entire circumference of the milk outlet channel 7. After rinsing the milk outlet channel 7 with the rinsing medium 24, it is directed into a drip tray located below the milk frothing device 2.

[0036] In the Fig. Figures 4a to 4c show different possibilities for the arrangement of the valve assembly 16.

[0037] As in Fig. As shown in 4a, it is possible to integrate the valve arrangement 16 into a lid 23 of the milk container 11.

[0038] As in the Fig. 4b, Fig. As shown in Figures 1 and 2, the valve arrangement 16 can also be arranged next to the milk container 11.

[0039] As in Fig. As shown in Figure 4c, it is also possible for the valve assembly to be arranged directly in the milk container 11. In this embodiment, a separate milk line between the valve assembly 16 and the milk container 11 is unnecessary.

Claims

[1] Beverage preparation device, in particular coffee machine (1A, 1B, 1C) with a milk frothing device (2) which has a nozzle device (3) for heating and / or frothing milk (9) by means of steam (5), wherein a vacuum can be generated with the nozzle device (3) when steam is applied, with which milk can be drawn from a milk reservoir (11) via a suction line (10) connected to the nozzle device (3) in a fluid-conducting manner, wherein the milk frothing device (2) further comprises a milk outlet channel (7) arranged downstream of the nozzle device (3) with an outlet opening (8) for milk foam, wherein the suction line (10) can be supplied with a rinsing medium and is connected in a fluid-conducting manner to a discharge line (14) for discharging rinsing medium from the suction line (10), characterized bya valve arrangement (16) comprising a first valve (17) arranged in the suction line (10) between the milk frothing device (2) and the milk reservoir (11) and a second valve (18) arranged in the discharge line (14), wherein when milk is drawn in the first valve (17) is in an open position and the second valve (18) is in a closed position and wherein when the suction line (10) is flushed with flushing medium the first valve (17) is in a closed position and the second valve (18) is in an open position, wherein the valves (17, 18) of the valve arrangement (16) are pressure-dependent self-switching check valves. [2] Beverage preparation device according to claim 1, characterized by, that a supply line (19) opens into the suction line (10), through which air can be supplied to the milk (9) during a milk frothing process and / or through which rinsing medium can be supplied to the suction line (10), which can flow directly from the suction line (10) into the nozzle assembly (3) of the milk frothing device (2) and / or via the suction line (10) into the discharge line (14). [3] Beverage preparation device according to one of claims 1 or 2, characterized by , that the valves (17, 18) of the valve arrangement (16) are spring-loaded plunger valves, diaphragm valves, slide valves and / or flap valves. [4] Beverage preparation device according to one of the preceding claims, characterized by, that an outlet end (20) of the discharge line (14) is arranged adjacent to the outlet opening (8) and preferably above a drip tray (21), so that rinsing medium can exit next to the outlet opening (8), in particular parallel to a milk discharge direction. [5] Beverage preparation device according to any one of claims 1 to 3, characterized by , that an outlet end (20) of the discharge line (14) opens upstream of the outlet opening (8), in particular via a connecting channel (15) into the milk outlet channel (7), so that rinsing medium can escape through the outlet opening (8). [6] Beverage preparation device according to any one of claims 1 to 3, characterized by , that an outlet (20) of the discharge line (14) opens, in particular via a connecting channel (15), into an annular chamber (22) surrounding the outlet opening (8) of the milk discharge channel (7). [7] Beverage preparation device according to one of the preceding claims, characterized by , that the valve arrangement (16) is arranged inside the milk reservoir (11) or inside a lid (23) of the milk reservoir (11) or outside the milk reservoir (11). [8] Beverage preparation device according to one of the preceding claims, characterized by , that the discharge line (14) in the area of ​​the valve arrangement (16) opens into the suction line (10) in a section between the milk frothing device (2) and the first valve (17). [9] Method for operating a beverage preparation device according to any one of claims 1 to 8, wherein, to produce a beverage, in particular a coffee specialty containing milk foam, steam (5) is first introduced into a nozzle assembly (3) of a milk frothing device (2), whereby a vacuum is generated in the nozzle assembly (3), with which milk (9) is drawn from a milk reservoir (11) connected to the nozzle assembly (3) via a fluid-conducting suction line (10) and directed into the nozzle assembly (3) of the milk frothing device (2), frothed there and finally discharged via a milk outlet channel (7),wherein, in a beverage production process, a first pressure-dependent, self-switching check valve (17) of a valve arrangement (16), arranged in the suction line (10) between the milk frothing device (2) and the milk reservoir (11), is in an open position, and a second pressure-dependent, self-switching check valve (18) of the valve arrangement (16), arranged in a discharge line (14) connected to the suction line (10) by a fluid-conducting connection, is in a closed position, and wherein, for a cleaning process, the first pressure-dependent, self-switching check valve (17) is moved to a closed position and the second pressure-dependent, self-switching check valve (18) is moved to an open position, and the suction line (10) is supplied with rinsing medium for cleaning. [10] Method according to claim 9, characterized by, that the first valve (17) and the second valve (18) of the valve arrangement (16) are electronically controllable, in particular by means of a push button.

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