Cleaning method for cleaning a milk-conducting system of a beverage machine

Abstract

A cleaning method, by way of which a milk-conducting system of a beverage machine, in particular a coffee machine, is cleaned, is characterized by comprising at least the following steps: A) providing the beverage machine (1) comprising a milk-conducting system (20) having a milk container (21, 21') which can be filled with milk; B) starting a cleaning process; C) emptying the milk from the milk container (21, 21') if it is not already completely empty at the point in time at which the cleaning process is initiated, D) filling the milk container (21, 21') with a cleaning fluid, and E) conducting the cleaning fluid from the milk container (21, 21') through the milk processing section (22).

Description

[0001] Cleaning method for cleaning a milk-carrying system of a beverage machine

[0002] The invention relates to a cleaning method for cleaning a milk-carrying system of a beverage machine, in particular a coffee machine, and to a device for carrying out the method.

[0003] The term "milk" is to be interpreted broadly in this document. It includes both animal milk and plant-based milk substitutes such as oat or almond milk. Within the scope of this application, a variety of "milk products" can be dispensed from the milk outlet, including milk at different temperatures, as well as milk foam or similar.

[0004] Various methods for cleaning the milk-carrying system of a beverage machine are known from the state of the art.

[0005] For example, EP 1 872 698 B1 proposes flushing the milk-carrying system with water. This water is then fed through the air supply hose into the milk processing section, which is designed as a milk frothing device. The supply hose is not cleaned but replaced with a new one at intervals.

[0006] EP 2 277 419 B1 discloses a beverage machine in which a milk supply line is integrated into a milk container. The milk container, including the milk supply line, is removed from the beverage machine and cleaned externally.

[0007] Finally, from WO 2015 / 135085 A1 it is known to separate the milk line, which serves to convey milk from the milk container into the milk processing section, from the milk container in order to then connect the milk line to a cleaning container containing a cleaning fluid, which is then passed through the rest of the milk-carrying system.

[0008] Against this background, the object of the invention is to create a further simplified cleaning method for cleaning a milk-carrying system of a beverage machine, in particular a coffee machine. Furthermore, a beverage machine with a milk-carrying system is to be created that is well suited for carrying out this cleaning method.

[0009] The invention solves this problem with regard to the method by the subject matter of claim 1 and with regard to the beverage machine by the subject matter of claim 12. Advantageous embodiments can be found in the dependent claims.

[0010] According to claim 1, a cleaning method is provided for cleaning a milk-carrying system of a beverage machine, in particular a coffee machine, wherein the milk-carrying system has at least one milk container, a milk line with an end section projecting into the milk container for conveying milk into a milk processing section and a milk outlet for dispensing milk or a milk product into a container, and wherein a cleaning agent supply line is further provided for supplying cleaning fluid into the milk container, and wherein the cleaning comprises at least the following steps:

[0011] A) Provision of the beverage machine,

[0012] B) Start cleaning, whereby the milk container may be empty or fully or partially filled with milk at this time,

[0013] C) Emptying the milk container of milk, if it is not already completely empty at the time the cleaning process is started,

[0014] D) Filling the milk container with a cleaning fluid, and

[0015] E) Pumping the cleaning fluid from the milk container through the milk line and the milk processing section and the milk outlet.

[0016] According to the invention, a simple to implement yet efficient cleaning method is created in which the milk container itself is surprisingly also used as a cleaning fluid container or as a container for holding the cleaning fluid.

[0017] What is particularly advantageous is that both the milk processing device and the milk container itself, as well as the milk line used to convey the milk from the milk container into the milk processing device, can be cleaned in a simple manner.

[0018] This further simplifies cleaning the milk system for the user. The cleaning process according to the invention is very simple. In particular, it is possible to start or initiate cleaning independently, meaning no preparatory steps need to be performed by the operating personnel. This eliminates the need to reconnect hoses or remove a container. The method requires only minimal design changes to a beverage machine according to the invention compared to a conventional beverage machine.

[0019] For cleaning, after initiating the cleaning process—for example, by starting the cleaning process with a control device at a specific time or at a predefined, stored time—any remaining milk is pumped out of the milk container and dispensed, for example, through the milk outlet. This milk is either discarded or returned to the container after cleaning is complete. The milk container itself is then used for cleaning, and the cleaning fluid dispensed into it is pumped through the rest of the milk system, thus cleaning it.

[0020] The cleaning method can be implemented in various ways. According to a particularly preferred advantageous variant, the cleaning agent supply line has an end section that runs into the milk container next to the end section of the milk line or ends above the milk container, through which the cleaning fluid is fed into the milk container in step D). This variant is particularly easy to implement. In this way, the milk container is supplied with cleaning fluid during cleaning via an additional line, and from there the cleaning fluid is distributed throughout the milk-carrying system.

[0021] However, an alternative advantageous variant can also be implemented in which the cleaning agent supply line for supplying cleaning fluid is connected to the milk line, in particular to the end section of the milk line, so that the cleaning fluid is guided through the end section of the milk line into the milk container in step D).

[0022] It is also advantageous to prevent cleaning agent from getting into the dairy products. When using the same container for cleaning agent and milk, this risk is generally present. However, it can be avoided in various ways. One approach is to use a conductivity sensor to determine the conductivity of the liquid flowing from the container. For example, by determining the conductivity and comparing it with pre-stored target conductivity values ​​for the milk, possibly water and a cleaning fluid with added cleaning agent) and enabling or blocking dispensing depending on the determined value, it can be ensured that the fluid coming out of the container no longer contains any cleaning agent (rinse).

[0023] Further advantageous variants of the method according to the invention are specified in subclaims 4 to 11, the subject matters of which are explained in more detail below.

[0024] The invention also provides a device for carrying out the method, which is designed as a beverage machine, in particular a coffee machine, which comprises the following: a beverage preparation section and a milk-carrying system, wherein the milk-carrying system has at least one milk container, a milk line with an end section projecting into the milk container for conveying milk into a milk processing section, the milk processing section and a milk outlet for dispensing milk or a milk product into a vessel, wherein the milk container is further assigned a cleaning agent supply line for supplying cleaning fluid into the milk container, and a control device on which a control program is loaded, with which the cleaning sequence is controlled.

[0025] In this way, a device is created in a simple manner which is particularly well suited for carrying out the method according to the invention.

[0026] Further advantageous variants of the method according to the invention are specified in subclaims 12 to 21, the subject matters of which are explained in more detail below.

[0027] The invention is described in more detail below using exemplary embodiments with reference to the drawings. The invention is not limited to these exemplary embodiments, but can also be implemented in other ways, either literally or in other equivalent ways. They show:

[0028] Fig. 1 is a schematic representation of a first embodiment of a beverage machine according to the invention, to which a milk refrigerator is assigned;

[0029] Fig. 2 is a schematic representation of a second embodiment of a beverage machine according to the invention, to which a milk refrigerator is assigned;

[0030] Fig. 3a, b in Fig. 3a) a schematic representation of the milk refrigerator of the beverage machine according to the type of Fig. 1 with the milk container, a milk line and a cleaning fluid line in a first state in which the milk container is partially filled with milk and in Fig. 3b) a schematic representation of the milk refrigerator from Fig. 3a) in a second state in which the milk container is partially filled with cleaning fluid;

[0031] Fig. 4a, b in Fig. 4a) a schematic representation of the milk refrigerator of the beverage machine according to the type of Fig. 2 with the milk container, a milk line and a cleaning fluid line in a first state in which the milk container is partially filled with milk and in Fig. 4b) a schematic representation of the milk refrigerator from Fig. 4a) in a second state in which the milk container is partially filled with cleaning fluid; and

[0032] Fig. 5 shows a flowchart of an embodiment of a cleaning method according to the invention. Figs. 1 and 2 each show a beverage machine 1 having a beverage preparation device 10 and a milk-carrying system 20. The beverage machine 1 further comprises a control device 30.

[0033] The beverage preparation device 10 can be designed, for example, for preparing a caffeinated beverage, in particular for preparing coffee. It has a brewing unit 11 and a beverage dispensing line 12 for dispensing the beverage prepared in the brewing unit 11 through a beverage outlet on a beverage dispenser 13 into a container, such as a cup, that can be placed below the beverage outlet. The brewing unit 11 can be assigned a water supply line 14, with which (in particular heated) water can be fed from a boiler 15 into the brewing unit 11. The boiler 15 is connected to a water line 141, into which a pump 142 can be connected via a connecting line 141. The brewing unit 11 can be designed in a variety of ways, for example for preparing a coffee in the style of an espresso coffee or for preparing a coffee of a different preparation method, such as filter coffee.Other optional elements such as a grinder for grinding coffee and the like are not shown here.

[0034] The milk-carrying system 20 is designed for holding and conveying milk, for preparing a milk product from the milk and for dispensing the milk or milk product, in particular from a milk outlet in the area of ​​the beverage dispenser 13, from which the milk or milk product can also be dispensed into a container.

[0035] The milk product can be a milk / air emulsion similar to milk foam. It can also be designed to dispense cold or warm milk without the addition of air from the milk-carrying system. The term "milk" is again broadly defined. It includes both animal milk and plant-based milk substitutes such as oat or almond milk.

[0036] The milk-carrying system 20 comprises a milk container 21, a milk processing section 22, and a milk line 23 between the milk container 21 and the milk processing section 22. It further comprises a milk dispensing line 24 extending from the milk processing section 22. This line can end, in particular, in the area of ​​the beverage dispenser 13 in the milk outlet (not shown here).

[0037] The milk container 21 can optionally be arranged in a milk refrigerator 25. The milk container 21 and, if applicable, the milk refrigerator 25 can be integrated directly into the beverage machine 1, but the milk container 21 and, if applicable, the milk refrigerator 25 can also be installed next to the beverage machine 1. For the purposes of this application, the milk container 21 and, if applicable, the milk refrigerator 25 form part of the beverage machine 1 in both cases.

[0038] The milk line 23 connects the milk container 21 to the milk processing section 22. A feed pump 231 can be connected to the milk line 23. It can also be provided that a controllable switching valve 232 is connected to the milk line 23, with which the liquid exiting the feed pump can be optionally further conducted through the milk line 23 to the milk processing device 22 or through a branch line 233 to the brewing unit 11.

[0039] The milk line 23 and a cleaning fluid supply line 40 open into the milk container 21. The milk container 21 can be designed as a container open at the top. In this case, it can advantageously be provided that the milk line 23 and the cleaning fluid line 40 each protrude from above into the milk container 21 with an end section 231, 401. However, it can also be provided that the end section 401 of the cleaning fluid supply line 40 does not protrude into the milk container 21, but ends above this milk container 21.

[0040] According to an advantageous embodiment, the milk container 21 can have a lid 29. The lid 29 and the end section 231, which can then be designed in the manner of a milk lance, can then be formed as a unit, with the milk lance virtually passing through the lid 29. Above the lid 29, the milk lance can be designed like an adapter to allow it to be easily connected to the milk line 23, which can have a corresponding adapter.

[0041] The end section 401—which can be designed as a cleaning lance—can end above the lid 29. The lid 29 can then have a through-opening (not shown) below the cleaning lance, so that cleaning fluid flowing from the end section 401 can reach the milk container 41.

[0042] Thus, according to the embodiments of Figs. 1 and 2, the milk refrigerator 25 has two fixed lances: a milk suction lance, which can be fastened to the lid of the milk container by means of a detachable adapter, and a fixed cleaning lance, which can in particular be shorter than the milk suction lance.

[0043] The cleaning fluid supply line 40 can be fluidly connected to the boiler 15 at its end facing away from the milk container 21. It can be provided with an input device 41 for introducing cleaning fluid or another cleaning agent. This input device 41 can be a dosing device for liquid or powdered cleaning agent, in particular for adding it to the water to form the cleaning fluid from water and cleaning agent.

[0044] The control device 30 is designed to control the beverage preparation device 10 and the milk-carrying system 20. It is also designed to control the cleaning of the milk-carrying system. The control device 30 can also optionally be designed to control the cleaning of the beverage preparation device 10. The control device 30 can have a computer unit and can be coupled to an input device not shown here (e.g., a screen with a touch-sensitive screen surface and / or buttons designed for inputting commands and / or a remote-control device such as a mobile phone with an app designed for inputting commands and / or for displaying information about the operating status).

[0045] The beverage machine of Fig. 2 can be constructed essentially like the beverage machine 1 of Fig. 1; it differs from the beverage machine 1 of Fig. 1 only in that the milk container 2T is designed as a type of intermediate container. The intermediate container can therefore be somewhat smaller than the milk container 22 of Fig. 1 (i.e., designed to hold a smaller volume of milk, which can potentially reduce milk losses during cleaning). The milk line 23 and the cleaning fluid (supply) line 40, in turn, open into the milk container 21'. The milk container 21' designed as an intermediate container can, in turn, be designed as a container open at the top.It can again advantageously be provided that the milk line 23 and the cleaning fluid line 40 each protrude with an end section 231, 401 from above into the milk container 2T designed as an intermediate container, or that the end section 401 ends above this milk container 2T. It can also be provided that the end section 401 of the cleaning fluid supply line 40 protrudes less far into the milk container 21' than the end section 231 of the milk line 23.

[0046] It is also provided that a milk reservoir 26 - for example a further container or tank or the like - is connected upstream of the milk container 21 ' designed as an intermediate container, from which milk can be fed into the milk container 2T designed as an intermediate container through an intermediate tank supply line 27, into which a milk pump 28 can be connected (Fig. 4a, 4b).

[0047] The beverage machine 1 and its milk refrigerator 25 shown in Figs. 1 and 2 are each operated in two modes: a milk intake mode (regular operation, Figs. 3a, 4a) and a cleaning mode, in which the cleaning process is carried out (see Figs. 3b, 4b). In regular operation (Figs. 3a, 4a), the milk is intake and, if necessary, processed and dispensed in the milk-carrying system.

[0048] In cleaning mode, however, the milk container 21, 21' is first emptied via the milk line 23 (drain or storage container under product dispensing). Subsequently, the milk container 21, 21' serves as a cleaning vessel, i.e., the cleaner is filled into the milk container 21, 21' up to the maximum fill level via the fixed cleaning lance 401 and then distributed via the milk suction lance in the machine or in the milk-carrying system 20.

[0049] This feature means that the milk system can be cleaned independently.

[0050] With the devices according to Figs. 1 and 2, a particularly advantageous cleaning method can be carried out, with which the milk-carrying system 20 of the beverage machine 1 is cleaned. This method (see Fig. 5) comprises at least the following steps:

[0051] A) Provision of the beverage machine 1 ,

[0052] B) Start the cleaning, whereby the milk container 21 , 2T can be emptied or filled with milk at this time,

[0053] C) Emptying the milk container 21, 21' of milk, provided that it is not already completely empty at the time the cleaning process is started,

[0054] D) Filling the milk container 21 , 21 ' with a cleaning fluid, and

[0055] E) Conveying the cleaning fluid from the milk container 21, 21' through the milk line 23 and the milk processing section 22 and preferably directly thereafter discharging the cleaning fluid from the milk outlet.

[0056] After cleaning, the milk supply system can be used again to provide milk or milk foam as a beverage additive. To do this, the milk container is first refilled with milk.

[0057] The term "cleaning fluid" should not be defined too narrowly. The cleaning fluid can be water, especially heated water. A cleaning agent such as a soluble cleaning powder or similar may be added to the water.

[0058] Steps D) and E) can be performed sequentially. However, it is also conceivable that the conveying of the cleaning fluid from the milk container 21, 21' through the milk processing section 22 and the dispensing of the cleaning fluid through the milk outlet 23 is started at the beginning of or shortly after the filling of the milk container 21, 21' with cleaning fluid, and then the conveying is continued in parallel with the filling.

[0059] Steps D) and E) can also be carried out two or more times in succession, e.g. with different cleaning fluids.

[0060] Thus, after emptying the milk, the milk container 21, 21' can first be filled with the cleaning fluid "water" (step D1) and the milk-carrying system 20 can be pre-rinsed (step E1), whereupon the milk container 21, 21' can then be filled again with a different cleaning fluid such as "water with added cleaning agent" (step D2) and the milk-carrying system is rinsed again, but this time with the different cleaning fluid (step E2). Optionally, the milk container 21, 21' can then be filled again with the cleaning fluid "water" (step D3) and the milk-carrying system 20 can be rinsed with water (step E3).

[0061] The milk processing section 22 is not shown in detail here, but preferably comprises at least the milk line, an air inlet, a steam inlet, and a milk pump. All of these elements can be easily cleaned using the cleaning method according to the invention.

[0062] It is clear that the cleaning process requires no preparatory steps. It can therefore also be started automatically, for example, at a time preset in the control device 30, such as at night.

[0063] It is also conceivable that the end section 401 is designed as a cleaning lance that protrudes into the milk container 21. It can then, for example, be designed like the milk lance 231 (next to it) (not shown).

[0064] It is also conceivable that two lines (end section 401 and end section 231) are formed next to each other in a single lance (not shown here).

[0065] As already explained, the cleaning lance can also extend into the milk container 21, 21' (analogous to the milk suction).

[0066] It is also conceivable not to provide a separate cleaning lance, but to also fill the milk container 21 for cleaning via the milk (suction) line 23, e.g., of Fig. 1 or Fig. 2. A switching valve (not shown) can then be connected to the milk line 23, either to supply it with cleaning fluid in a first position or to connect it to the milk processing device 22.

[0067] It is also conceivable (not shown) to work with two milk containers and four lances, cleaning the milk containers alternately and pumping any residual milk from the container being cleaned into the other container via a connecting line. This way, little or no milk is lost during cleaning.

[0068] Finally, by switching the optional switching valve 232 (e.g., a two-way valve), the cleaning fluid can be alternatively conveyed through the brewing unit 11 and through the beverage outlet in order to also clean these sections with the cleaning fluid from the milk container 21, 21'. It is also conceivable to distribute the cleaning fluid to other systems (not shown here). For example, it is conceivable that a syrup system and / or an instant system, which could also be cleaned from the milk container using appropriate branch lines.

[0069] To ensure that the cleaning time is not extended, or only slightly, by using the milk container 21' as a cleaning fluid reservoir, the design of Fig. 4a / 4b can be advantageously used. This is because, in this design, the smaller volume of the container 21' shown in Fig. 4a, b compared to Fig. 3a, 3b allows only smaller quantities of liquid to be pumped into and out of the container 21' - the milk container 21' should preferably be completely filled during cleaning. In this way, the cleaning time and water consumption are significantly reduced compared to the design shown in Fig. 3a and 3b.

[0070] Reference symbol

[0071] Beverage machine 1

[0072] Beverage preparation device 10

[0073] Brewing unit 11

[0074] Beverage dispensing line 12

[0075] Beverage dispenser 13

[0076] Water supply line 14

[0077] Water pipe 141

[0078] Pump 142

[0079] Boiler 15 milk-carrying system 20

[0080] Milk container 21 , 21 '

[0081] Milk processing section 22

[0082] Milk line 23

[0083] Feed pump 231

[0084] Changeover valve 232

[0085] Branch line 233

[0086] Milk dispensing line 24

[0087] Refrigerator 25

[0088] Milk reservoir 26

[0089] Intermediate tank supply line 27

[0090] Breast pump 28

[0091] Lid 29

[0092] Control device 30

[0093] Detergent supply line 40

[0094] Input device 41

Claims

Claims 1) Cleaning method for cleaning a milk-carrying system of a beverage machine, in particular a coffee machine, wherein the milk-carrying system has at least one milk container (21, 21'), a milk line (23) with an end section (231) projecting into the milk container (21, 21') for conveying milk, a milk processing section (22) and a milk outlet for dispensing milk or a milk product, wherein a cleaning agent supply line (40) is also provided for supplying cleaning fluid into the milk container (21, 21'), characterized in that the cleaning comprises at least the following steps: A) Provision of the beverage machine (1 ), B) Start the cleaning, whereby the milk container (21 , 2T) can be emptied or filled with milk at this time, C) Emptying the milk container (21, 21') of milk, provided that it is not already completely empty at the time the cleaning process is started, D) filling the milk container (21, 21') with a cleaning fluid, and E) conveying the cleaning fluid from the milk container (21, 21') through the milk line (23) and the milk processing section (22). 2) Method according to claim 1, characterized in that the cleaning agent supply line (40) has an end section (401) through which the cleaning fluid is guided in step D) into the milk container (21, 21'), which is guided next to the end section of the milk line (231) into the milk container (21, 21') or ends above the milk container (21, 21'). 3) Method according to claim 2, characterized in that the cleaning agent supply line (40) for supplying cleaning fluid is connected to the milk line, in particular to the end section (231) of the milk line, so that the cleaning fluid is passed in step D) through the end section (231) of the milk line (23) into the milk container (21; 21'). 4) Method according to claim 3, characterized in that the cleaning agent supply line (40) can be connected to the end section (231) of the milk line by means of a changeover valve. 5) Method according to one of the preceding claims, characterized in that water is used as the cleaning fluid, in particular heated water, to which a cleaning agent may be added 6) Method according to one of the preceding claims, characterized in that step E) comprises dispensing the cleaning fluid through the milk outlet. 7) Method according to one of the preceding claims, characterized in that steps C) and step D) are carried out one after the other or are partially carried out in an overlapping manner. 8) Method according to one of the preceding claims, characterized in that steps C) and D) are repeated several times. 9) Method according to claim 8, characterized in that steps C) and D) are repeated several times with different cleaning fluids. 10) Method according to one of the preceding claims, characterized in that steps C) and D) are first carried out with water as the cleaning fluid "water" and that they are then carried out again with water as the cleaning fluid to which a cleaning agent has been added. 11) Method according to one of the preceding claims, characterized in that two of the milk containers are provided which can be connected to the milk line (23) and with which steps C), D) and E) are carried out alternately. 12) Device for carrying out the method according to one or more of the preceding claims, characterized in that it is designed as a beverage machine, in particular a coffee machine, comprising the following: a. a beverage preparation section (10) and b. a milk-conveying system (20), wherein the milk-conveying system comprises at least i. a milk container (21, 21'), ii. a milk line (23) with an end section (231) projecting into the milk container (21, 21') for conveying milk into a milk processing section (22), iii. the milk processing section, and iv. a milk outlet for dispensing milk or a milk product into a container, v. wherein the milk container (21, 21') is further provided with a cleaning agent supply line for supplying cleaning fluid into the milk container (21, 21'), and c. a control device (30) onto which a control program is loaded, with which the cleaning process is controlled. 13) Device according to claim 12, characterized in that the beverage machine is further assigned a milk refrigerator (5) in which the milk container (21, 21') is arranged. 14) Device according to claim 12 or 13, characterized in that the cleaning agent supply line (40) has an end section (401) through which the cleaning fluid can be conducted into the milk container (21, 21'), wherein the end section (401) is guided into the milk container (21, 21') next to the end section of the milk line (231) or ends above the milk container (21, 21'). 15) Device according to claim 12 or 13, characterized in that the cleaning agent supply line (40) can be connected to the end section (231) of the milk line by means of a changeover valve, so that the cleaning fluid can be conducted through the end section (231) of the milk line (23) into the milk container (21; 21'). 16) Device according to one of the preceding claims, characterized in that the cleaning agent supply line (40) is in fluid connection with a boiler (15) of the beverage machine. 17) Device according to one of the preceding claims, characterized in that the end section (231) of the milk line (23) is designed as a milk lance which is designed as a structural unit with a lid (21, 21') of the milk container (21, 21'). 18) Device according to one of the preceding claims, characterized in that the milk container (21') is designed as an intermediate container which is in fluid communication with a milk reservoir (26) arranged upstream thereof. 19) Device according to one of the preceding claims, characterized in that two of the milk containers are provided which can be connected to the milk line (23) and with which steps C), D) and E) can be carried out alternately. 20)Device according to one of the preceding claims, characterized in that the milk processing section (22) comprises at least one air inlet and one steam inlet and a milk feed pump (231).

21. Device according to one of the preceding claims, characterized in that the cleaning agent supply line (40) has an input device (41) for a cleaning agent.

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