METHOD FOR OPERATING A DEVICE FOR FROZEN MILK AND DEVICE FOR FROZEN MILK

Abstract

The invention relates to a method for operating a device (10) for frothing milk (20), in which the device (20) comprises a steam source (12) for providing steam for frothing the milk (29); a container (44) provided in addition to the steam source (12) for receiving a liquid (46); and a pump (48) by means of which the liquid (46) is to be conveyed from the container (44) into the steam source (12); and wherein the device (10) is operated in a descaling mode in which, by means of the pump (48), the liquid (46) is conveyed from the container (44) into the steam source (12) in such a targeted manner that the steam source (12) is completely filled with the liquid (46).

Description

[0001] The invention relates to a method for operating a device for frothing milk according to the preamble of patent claim 1. Furthermore, the invention relates to a device for frothing milk.

[0002] EP 1 501 398 B1 discloses a device for heating and frothing milk, particularly for preparing cappuccinos in a coffee machine. It includes a steam-generating hot water heater. Also provided are conveying means with an open end, which can be immersed in a container containing milk.

[0003] In devices known from the general state of the art for frothing milk, a steam source is used, usually referred to as a boiler or designed as a boiler, by means of which steam, particularly in the form of water vapor, can be provided. After frequent use of such a device and thus its steam source, limescale can form in the steam source, which accumulates on the steam source, particularly in its interior. Removing the limescale from the steam source, also known as descaling the steam source, is usually very time-consuming and costly.

[0004] The object of the present invention is therefore to provide a method for operating a device for frothing milk and a device for frothing milk, so that a particularly time- and cost-effective descaling can be realized.

[0005] This object is achieved according to the invention by a method having the features of patent claim 1 and by a device having the features of patent claim 15. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0006] A first aspect of the invention relates to a device for frothing and preferably also for heating milk. By frothing the milk, a milk foam can be formed. The milk foam can be used, for example, to prepare a hot beverage such as a hot coffee beverage, in particular a cappuccino. Thus, for example, it is provided that in the method the device is part of a beverage maker, in particular a hot beverage maker. In the method, the device has a steam source for providing steam, in particular water vapor. In other words, the steam source is preferably a water vapor source for providing water vapor. In other words, steam, in particular water vapor, can be provided by means of the steam source. The steam source can be a so-called boiler.In particular, a boiler is understood to mean a steam boiler, for example. It is also conceivable that the steam source is a continuous-flow heater for generating and providing steam. The generation of steam is also referred to as steam generation or steam provision.

[0007] For example, the device in the method can have a first line element through which the steam provided by the steam source can flow. The first line element has an end, in particular an open and very preferably free end, through which the steam flowing through the first line element can flow. Thus, for example, the steam flowing through the first line element can flow out of the first line element via the end of the first line element and thereby flow in particular to or into an area surrounding the first line element, in particular the device. The open end is immersible or can be immersed in a container provided for holding the milk.Thus, for example, at least a portion of the first conduit element encompassing the end can be immersed into the container and, in particular, into the milk contained in the container, in particular such that, for example, the end is positioned below a level of the milk in the container, also referred to as the level. The container can, but does not necessarily have to, be a component of the device.

[0008] In the method, the device can, for example, comprise an air pump, in particular an electrically operated one, for providing compressed air. Compressed air is understood to mean, in particular, air that has a pressure, also referred to as air pressure, for example, where the pressure of the air, in particular relative to atmospheric pressure, can preferably be greater than 1 bar, in particular greater than 1.5 bar, and most particularly greater than 2 bar. In particular, when the air pressure is related to atmospheric or ambient pressure, the air pressure is an overpressure relative to atmospheric or ambient pressure.

[0009] In the method, the device can, for example, have a second line element through which the compressed air provided or can be provided by the air pump can flow or through which it flows. The compressed air flowing through the second line element can be introduced via the second line element into the first line element and thus into the steam flowing through the first line element. For this purpose, the second line element is, for example, fluidically connected or connectable to the first line element at a connection point, so that, for example, the compressed air flowing through the second line element can flow out of the second line element at the connection point and into the first line element.In this case, it is preferably provided that, in the flow direction of the steam flowing through the first conduit element, the connection point is arranged upstream of the end of the first conduit element and in particular downstream of the steam source. For example, a length of the first conduit element can extend from the connection point to the end. For example, the first conduit element ends at the end, wherein it is preferably provided that the length ends at the end.Since, for example, at the connection point the compressed air from the second line element can be introduced into the first line element and into the steam flowing through the first line element, the steam flowing through the first line element and the compressed air introduced into the first line element can, for example, flow through the said length range, in particular together, and thus, for example, flow, in particular together, from the connection point to the end of the first line element, flow through the end of the first line element and thus flow out of the first line element via the end of the first line element and thereby flow into or onto the said environment.If the end of the first line element is immersed in the milk while the steam and the compressed air flow through the end and thus flow out of the first line element via the end, the steam and the compressed air flow, in particular together, into the milk, whereby the milk is frothed and in particular heated. For example, the steam flowing out of the end has a temperature which is greater than 90 degrees Celsius. In particular, the temperature of the steam flowing out of the end is greater than or equal to 100 degrees Celsius. In particular, for example, a phase mixture of the steam, water droplets and the compressed air flows out of the end, wherein the phase mixture flowing out of the end has, for example, the mentioned temperature which is greater than 90 degrees Celsius, in particular greater than or equal to 100 degrees Celsius.In other words, at least the steam and compressed air can flow through the end of the first conduit element, thereby introducing the steam and air into the milk through the end. This allows the milk to be frothed, thus creating milk foam. Furthermore, the milk can be heated.

[0010] Alternatively or additionally, the device may comprise a Venturi nozzle for providing the air and / or steam and / or a steam lance for providing the steam.

[0011] For example, in the method, the device can be operated in a frothing mode, also referred to as steam mode or steam supply mode. In the frothing mode, i.e., during at least part of the frothing mode, the steam source provides the steam, which thus flows through the first conduit element, for example, in the frothing mode, i.e., at least during part of the frothing mode.

[0012] In the method, the device has a container for holding a liquid, which is provided in addition to the steam source. This means that the liquid can be held or is held in the container. In other words, it is conceivable that during the method, i.e. during at least part of the method, the liquid is held in the container. The container for holding the liquid is also referred to as the second container. When reference is made above and below to the container, this means, unless otherwise stated, the second container for holding the liquid. In this case, the steam source is in particular a first container or the steam source is also referred to as the first container.For example, particularly in the frothing mode, the steam can be generated in the steam source, i.e., in the first container, and temporarily stored in the steam source. For example, the steam can be provided by the steam source in such a way that the steam generated in the steam source is removed from the steam source, i.e., guided out, and, in particular, introduced into the first conduit element. Thus, for example, the first conduit element is fluidly connected or connectable to the steam source, so that the steam generated in the steam source can be removed from the steam source and introduced into the first conduit element.

[0013] For example, in or during the frothing mode, that is to say when the pump is operated in the frothing mode, the liquid can be water, in particular liquid water, which can be or is received in the container, in particular initially, in a liquid state, wherein the steam is generated from the water received in the container in the frothing mode, in particular as water steam by means of and very particularly in the steam source, which can then provide or provides the generated steam, in particular in the frothing mode.

[0014] In the method, the device comprises a liquid pump, also referred to simply as a pump, by means of which the liquid can be conveyed from the container to the vapor source. When reference is made to the pump above and below, unless otherwise stated, this refers to the liquid pump by means of which the liquid can be conveyed from the container to the vapor source.In particular during or in the frothing mode, the liquid, which in particular in the frothing mode is in the form of water and is initially held in the container in a liquid state, is pumped from the container into the steam source by means of the pump (liquid pump), i.e. is pumped out of the container and into the steam source, in and by means of which, in and during the frothing mode, the steam is generated from the liquid pumped from the container into the steam source by means of the pump, which steam is provided by the steam source during or in the frothing mode. In particular, it is provided that with an increasing quantity of liquid pumped from the container into the steam source by means of the pump, a level of the liquid in the steam source, also referred to as the level, liquid level or fill level, increases, in particular along one direction.In particular, the direction is or runs in a vertical direction, particularly with respect to a position of use of the device which, in its position intended for its intended use, assumes the position of use, and is therefore in the position of use.

[0015] In order to provide the steam by means of the steam source, the liquid held in the steam source is warmed, i.e. heated, for example by means of and very particularly in the steam source, in particular to at least or above its boiling point. Frequent use of the device and thus of the steam source can lead to the formation of limescale in the steam source, which can precipitate or accumulate on the steam source. In particular, it is provided that the steam source has an inner peripheral surface by which a receiving space is delimited, in particular directly, wherein the liquid can be pumped from the container into the receiving space and thus into the steam source by means of the pump. The liquid can thus be held in the receiving space or in particular in or during the frothing mode. The limescale can accumulate in particular on the inner peripheral surface.The buildup of limescale in and on the steam source is also referred to as calcification or calcification of the steam source. Removing limescale from and on the steam source is usually a very time-consuming and costly process. This process requires, for example, the user to send the device to a maintenance station, which may be quite far away, where the device is laboriously dismantled and the steam source is descaled. The device is then reassembled and sent back to the user. The at least partial removal of limescale from and on the steam source is also referred to as descaling or decalcification. During descaling, the limescale is removed, for example, from the inner peripheral surface and from the steam source.In particular, in the context of the present disclosure, the descaling of the steam source, also referred to as descaling, is to be understood as meaning that limescale deposited on the inner circumferential surface and thus in and on the steam source, which is initially located in the receiving space, is at least partially detached from the inner circumferential surface and thus from the steam source and removed from the steam source, i.e. from the receiving space.

[0016] In order to be able to descale the steam source, in particular the inner peripheral surface, in a particularly time- and cost-effective manner and in a particularly extensive manner, i.e. over a particularly large area, without the device having to be disassembled and then reassembled by a person in a time- and cost-intensive manner, the invention provides that the device is operated in a descaling mode during the method. For example, the descaling mode follows the frothing mode in time, or the descaling mode precedes the frothing mode in time. For example, an operation of the operating element by a person is detected by means of at least one operating element of the device, wherein, depending on the detection of the operation of the operating element by the person, the device is operated in the descaling mode, and thus the descaling mode is started.In and thus during the descaling mode, the pump pumps the liquid from the container into the steam source, i.e., the receiving chamber, in such a way that the steam source, i.e., the receiving chamber, is completely filled with the liquid. This means that in or during the descaling mode, i.e., during at least part of the descaling mode, the liquid is absorbed into the container.The feature that in the method the liquid is conveyed from the container into the steam source in a targeted manner by means of the pump in such a way that the steam source is completely filled with the liquid is to be understood that the complete filling of the steam source with the liquid brought about by the pump, i.e. the complete filling of the steam source with the liquid resulting from the conveyance of the liquid from the container into the steam source by means of the pump, is a technically targeted process, i.e. one brought about consciously or intentionally and thus not accidentally or arbitrarily, which is carried out in particular by controlling, in particular regulating or controlling, the pump.In particular, it is provided that in or during the descaling mode, i.e. at least during part of the descaling mode, the liquid is a descaling liquid, also simply referred to as a descaler, which comprises, for example, water and at least one additive, also referred to as an additive, which is designed to loosen the limescale deposited in and on the steam source, i.e. on the inner circumferential surface, from the steam source, i.e. from the inner circumferential surface. According to the invention, it is thus provided that the pump can be and is operated in its fully assembled state in the descaling mode, wherein in the descaling mode the steam source is completely filled with the liquid from the container.As a result, the descaler can reach at least almost the entire inner circumferential surface, and thus directly touch at least almost the entire inner circumferential surface, as a result of which the steam source can be descaled over a particularly large area, particularly on the inner circumference, without having to disassemble the device. Because the steam source is completely filled with liquid from the container in descaling mode, the level of liquid forming in the container in descaling mode rises, particularly when viewed along the aforementioned direction, up to a source end of the steam source, also simply referred to as the end, which, particularly when viewed along the direction, ends at the source end, so that in descaling mode the level of liquid forming in the steam source in descaling mode rises, particularly when viewed along the direction, to a considerably higher level than in frothing mode.

[0017] If, in particular after the steam source has been completely filled with the liquid in the descaling mode, the liquid formed in the descaling mode, for example as a descaler, is removed from the steam source in the descaling mode, the steam source can be descaled particularly advantageously.

[0018] In order to be able to descale the steam source particularly advantageously, one embodiment of the invention provides that in the descaling mode, the liquid is pumped from the container into the steam source several times in succession in a targeted manner such that the steam source is completely filled with the liquid several times in succession. Thus, for example, in the descaling mode, several, i.e. at least two or more than two, filling processes are carried out in succession, wherein during the respective filling process carried out in the descaling mode, the liquid is pumped from the container into the steam source several times in succession in a targeted manner such that the steam source is completely filled with the liquid during the respective filling process.It is preferably provided that in the descaling mode, between each two consecutive filling processes, at least one or exactly one discharge process is carried out, in which the liquid is, in particular in a targeted manner, at least partially discharged from the steam source.

[0019] Filling the steam source completely several times in succession is also advantageous in that, for example, if the descaler removes limescale from the steam source, i.e., from the inner peripheral surface, carbon dioxide (CO2) can be generated, which can result in at least a portion of the descaler being expelled from the steam source without this being intentionally caused. Particularly effective descaling of the steam source can be ensured by subsequently refilling the steam source completely with the liquid.

[0020] A further embodiment is characterized in that, in the descaling mode and preferably during the filling process by means of the pump, the liquid is pumped from the container into the steam source in such a targeted manner that the steam source is overfilled with the liquid, so that the liquid pumped into the steam source by the pump flows over an edge of the steam source, for example, located at the source end or forming the source end, and thereby flows out of the steam source. This ensures complete filling of the steam source, which allows for particularly advantageous descaling of the steam source.

[0021] In a further, particularly advantageous embodiment of the invention, it is provided that in the descaling mode, the liquid is conveyed from the container into the steam source several times in succession in a targeted manner by means of the pump, i.e. the chronologically successive filling processes are carried out in such a way that the steam source is overfilled with the liquid several times in succession, so that the liquid conveyed into the steam source by means of the pump flows over the edge of the steam source several times in succession and thereby flows out of the steam source several times in succession.This means that during each filling process, which is carried out in descaling mode, the pump pumps the liquid from the container into the steam source in such a targeted manner that the steam source is overfilled with liquid during the respective filling process. This causes the liquid pumped into the steam source to overflow the edge and thus over the end of the steam source, thus flowing out of the steam source. This allows the steam source to be descaled particularly effectively and efficiently, as well as in a time- and cost-effective manner.

[0022] A further embodiment is characterized in that in at least one operating mode of the device that differs from the descaling mode and is intended for providing steam, in particular in all operating modes of the device that differ from the descaling mode and are intended for providing steam, the pump does not deliberately convey the liquid from the container into the steam source in such a way that the steam source is completely filled with the liquid from the container. In particular, the aforementioned operating mode is, for example, the aforementioned frothing mode.Thus, it is preferably provided that the steam source is preferably only completely filled with the liquid in the descaling mode; in the operating mode, in particular in the frothing mode, the steam source is not completely filled with the liquid from the container, whereby the steam can be generated and provided in a particularly advantageous manner. Thus, for example, the level of the liquid in the container that forms in the operating mode rises at most to a point that is, in particular viewed along the direction, distant from the edge and thus from the source end, and is located in particular below the edge or below the source end.An area of ​​the steam source, i.e., the receiving space, extending particularly along the direction from the point to the source end or to the edge, is free of liquid, so that the steam collects in this area, i.e., can initially be absorbed, particularly in the frothing mode. This leads to calcification of the steam source, particularly in this area. Because the steam source is completely filled with liquid in the descaling mode, the liquid, and thus the descaler, also reaches the area in the descaling mode, allowing the steam source to be descaled particularly extensively and in a particularly time- and cost-effective manner.

[0023] In a further embodiment of the invention, the device has at least one detection element, in particular at least partially arranged on and / or in the steam source, in particular the receiving space, for detecting a quantity of the liquid pumped from the container into the steam source by means of the pump. For example, the detection element is or comprises an electrode. In this case, it is preferably provided that in the descaling mode, the liquid is pumped from the container into the steam source by means of the pump in a targeted manner such that the level of the liquid in the steam source formed by the liquid pumped from the container into the steam source by means of the pump rises, in particular viewed along the direction over at least a part, in particular over at least a predominant part and thus over at least more than half, of the detection element and the steam source is completely filled with the liquid.This allows the steam source to be descaled extensively in a particularly time- and cost-effective manner.

[0024] In order to be able to reliably at least completely fill or even overfill the steam source in descaling mode, a further embodiment of the invention provides that in descaling mode and while the pump is pumping the liquid from the container into the steam source in descaling mode, a measured variable is recorded by means of a flow sensor, which characterizes a flow of the liquid flowing from the container into the steam source, caused by the pump. The measured variable is a flow rate of the liquid pumped by the pump, or the measured variable is also referred to as flow rate. In particular, the measured variable is, for example, a volume flow or a mass flow. In particular, the measured variable is a volume flow or a mass flow of the liquid pumped by the pump.Furthermore, it is provided that in the descaling mode, the liquid is pumped from the container into the steam source by means of the pump in a targeted manner depending on the measured variable detected by the flow sensor in such a way that the steam source is completely filled with the liquid.

[0025] In order to be able to descale the steam source in a particularly time- and cost-effective manner, it is provided in a further embodiment of the invention that in the descaling mode, from a point in time at which the level of the liquid in the container is at the same height as the part of the detection element and as a result the detection element detects the level of the liquid in the container, the pump is operated for a predetermined period of time, which is stored, for example, in an electrical or electronic data storage device, in particular for a longer period of time, in particular independently of a flow rate of the liquid conveyed by the pump measured by means of a flow sensor,whereby, by means of the pump, in particular independently of a flow rate of the liquid conveyed by the pump measured by means of a flow sensor, the liquid is conveyed from the container into the steam source during the period of time and the level rises at least over the part of the detection element, in particular viewed along the direction.

[0026] In order to achieve particularly time-efficient, cost-effective, and particularly comprehensive descaling of the steam source, it has proven particularly advantageous if, in the descaling mode, the pump conveys the liquid from the container into the steam source without a flow sensor being used to record a measured variable that characterizes a flow of the liquid flowing from the container into the steam source, caused by the pump. In other words, it is preferably provided that, in the descaling mode, the pump conveys the liquid from the container into the steam source without a flow sensor being used to measure a volume or mass flow of the liquid conveyed by the pump.

[0027] Very preferably, the time period is stored in a data memory, particularly an electrical or electronic memory, of an electronic computing device, in particular of the device. The method is preferably carried out by means of the electronic computing device, so that, in particular, the descaling mode is stored by means of the electronic computing device. In particular, it is provided that the electronic computing device controls the pump at least in the descaling mode.

[0028] In order to be able to descale the steam source in a particularly time-efficient and cost-effective manner as well as in a particularly comprehensive manner, a further embodiment of the invention provides that the time period for each execution of the descaling mode is constant.

[0029] In a further, particularly advantageous embodiment of the invention, it is provided that after the steam source has been completely filled with the liquid in the descaling mode, in particular overfilled, the liquid is drained from the steam source in the descaling mode, in particular in a targeted manner, as a result of which the steam source is at least predominantly and thus at least more than half, in particular completely, emptied of the liquid in the descaling mode, whereupon in the descaling mode the liquid is again pumped from the container into the steam source in a targeted manner by means of the pump such that the steam source is again completely filled with the liquid, in particular overfilled.This allows, for example, after the steam source has been completely filled with the liquid, the steam source to be rinsed with the liquid so that, for example, the descaler can be completely rinsed out of the steam source using water.

[0030] This allows the steam source to be descaled in a particularly time-efficient, cost-effective and advantageous manner.

[0031] In order to be able to descale the steam source particularly effectively and efficiently as well as in a particularly time- and cost-effective manner, it is provided in a further embodiment of the invention that after the steam source has been completely filled with the liquid in the descaling mode, the liquid is discharged from the steam source in the descaling mode in such a way, in particular in a targeted manner, that the liquid in the steam source is heated to over 100 degrees Celsius, whereby steam is generated from the liquid in the steam source with a steam pressure by means of which the liquid is expelled from the steam source via at least or exactly one opening of the steam source, in particular in a targeted manner.

[0032] A further embodiment is characterized in that the device is operated as a component of a beverage maker, in particular a hot beverage maker and especially a coffee machine, whereby a particularly time- and cost-effective descaling can be achieved.

[0033] A second aspect of the invention relates to a device for frothing milk, wherein the device is designed to carry out a method according to the first aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0034] For example, particularly in the frothing mode, the steam is generated by means of and in the steam source in such a way that in the frothing mode the liquid in the steam source is heated to, in particular at least, 130 degrees Celsius, wherein preferably the steam source, i.e. the receiving space in the frothing mode, is filled with the liquid to a maximum of 50%. Thus, in the frothing mode, the liquid received in the steam source can be adjoined, in particular along the direction and most particularly viewed upwards, by the aforementioned region in which the steam can be temporarily absorbed. The descaling mode according to the invention now makes it possible to decalcify the steam source, which is designed, for example, as a steam boiler or also referred to as a steam boiler, even in the aforementioned region, which is free of liquid in the frothing mode.For this purpose, in contrast to the frothing mode, also known as normal operation, the steam source is completely filled with the liquid, so that in the descaling mode, the liquid also reaches the aforementioned area. This allows the area to be descaled as well. In other words, in the descaling mode, the steam source is deliberately completely filled or even overfilled with the liquid. Preferably, in the descaling mode, the steam source is completely filled, or even overfilled, with the liquid several times in succession.During descaling mode, carbon dioxide can form in the steam source, which, for example, causes the liquid to be expelled from the steam source in particular via a steam valve and / or the aforementioned opening in descaling mode, whereupon the steam source is no longer completely filled with liquid, but only to, for example, approximately 95% to 98%. In order to be able to descale almost the entire interior, the steam source is filled or even overfilled several times in succession in descaling mode so that, for example, liquid expelled from the steam source due to the formation of carbon dioxide can be replaced, i.e. refilled. Furthermore, the invention makes it possible, for example, to rinse out the descaler, in particular with fresh water. Here, for example, the steam source is completely filled or even overfilled with liquid in descaling mode.The descaler is flushed out of the steam source, for example, by completely filling or overfilling the steam source with the liquid, preferably fresh water, and then completely draining the liquid, for example, by expelling the liquid through the opening as described above. This complete filling or overfilling and the subsequent, particularly complete draining to flush the steam source is performed several times, for example, two to three times consecutively, to ensure that an excessive amount of descaler remains in the steam source.

[0035] The hot beverage maker, especially the coffee machine, is preferably a portafilter machine.

[0036] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combinations, but also in other combinations or on their own, without departing from the scope of the invention.

[0037] The drawing shows: Fig. 1 is a schematic representation of a device for frothing milk; and Fig. 2 a schematic sectional view of a steam source of the device.

[0038] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0039] Fig. 1 shows a schematic representation of a device 10 for frothing milk, thus for producing or manufacturing milk foam from said milk. The device 10 has a steam source 12 for providing steam, in particular water vapor. For example, the steam source 12 is a steam boiler, also referred to simply as a boiler, or a continuous-flow heater for steam generation. The device 10 has a first conduit element 14 through which the steam, thus the steam provided or capable of being provided by the steam source 12, can flow. The first conduit element 14 has an end 16, in particular an open end, which can be immersed in a container 18 intended for receiving the milk and designed, for example, as a jug, in particular as a milk jug. Fig. 1 is in the container 18 the Fig. 1 particularly schematically shown milk and labelled 20, whereby in Fig. 1, the end 16 of the first conduit element 14 is immersed in the container 18 and thereby into the milk 20 contained in the container 18. Steam can flow through the end 16 of the first conduit element 14, so that the steam can be introduced or is introduced into the milk 20 via the end 16.

[0040] The device 10 also has an electrically operated air pump 22, which is also simply referred to as an air pump or pump. By means of the air pump 22, compressed air, which is also simply referred to as air, can be provided or is provided. The device 10 also has a second line element 24, through which the compressed air that can be provided or is provided by the air pump 22 can flow or flows. The compressed air can be introduced or is introduced into the first line element 14 via the second line element 24. For this purpose, the second line element 24 is fluidically connected or connectable to the first line element 14 at a connection point V. Fig. 1 that a length L of the first line element 14 extending from the connection point V, in particular continuously, to the end 16 and having the end 16 can be flowed through by the steam from the steam source 12 and by the compressed air conveyed by the air pump 22. Furthermore, it can be seen that the line element 14 and the length L end at the end 16. Thus, the end 16 can be flowed through by both the steam and the compressed air, so that both the steam and the compressed air are introduced or can be introduced into the milk 20 via the end 16 in order to thereby Fig. 1 to produce, and thus manufacture, milk foam designated 26. In other words, both steam and compressed air can flow through end 16, thereby introducing the steam and compressed air into the milk 20 via end 16 and subsequently producing, and thus manufacturing, the milk foam 26.

[0041] In the Fig. 1, the air pump 22 has, for example, a conveying element 28, which, for example, is arranged in a Fig. 1, is movably received in the pump housing of the air pump 22, which is not shown in more detail and is also referred to as the housing. This means that the conveying element 28 is movable relative to the pump housing. By moving the conveying element 28 relative to the pump housing, the compressed air is or will be provided by means of the air pump 22. The air pump 22 also has an electric motor 30, also simply referred to as a motor, by means of which the conveying element 28 can be driven and is thus movable relative to the pump housing in order to convey and provide the compressed air. The electric motor 30 is electrically operable, so that by electrically operating the electric motor 30, the air pump 22 is electrically operated and the conveying element 28 is electrically driven. This provides the compressed air.The electric motor 30 has, for example, a stator and a rotor, which can be driven in particular by electrically operating the electric motor 30 by means of the switch and can thus be rotated or is rotated about a machine axis of rotation relative to the stator. Thus, by driving the rotor at a respective speed about the machine axis of rotation relative to the stator and in particular relative to the pump housing, the rotor can be rotated. The air pump 22 can generate, i.e., cause, a quantity of compressed air flowing through the line element 24, for example in the form of a volume and / or mass flow. In addition, the air pump 22 can, for example, cause, i.e., cause, a pressure of the compressed air, also referred to as air pressure. The quantity and / or the air pressure depend, for example, on the speed of the rotor, hence of the air pump 22.

[0042] In order to be able to produce, and therefore manufacture, the milk foam 26 in a particularly simple and particularly convenient manner, the device 10 has an electronic computing device 32, also referred to as a control unit, which is designed to control the air pump 22, in particular electrically, and thereby to vary the operation of the air pump 22 in order to vary the amount of compressed air flowing through the second line element 24 and / or the pressure of the compressed air in at least one of the line elements 14, 24, in particular the second line element 24. The, in particular electrical, control of the air pump 22 by the electronic computing device 32 is in Fig. 1 by an arrow 34. For example, the computing device 32 can provide at least one signal, in particular an electrical one, also referred to as a control signal, by means of which the air pump 22 can be controlled or is controlled. In particular, the air pump 22 can receive the control signal, whereby the electronic computing device 32 can control, in particular regulate, the air pump 22 by means of the control signal. For example, by controlling the air pump 22, the electronic computing device 32 can vary a supply of the air pump 22, in particular the electric motor 30, with an electrical voltage, for example in the form of an electrical direct voltage, in order to thereby vary the operation of the air pump 22. Furthermore, it is conceivable that the electronic computing device 32 can control the air pump 22 by means of pulse width modulation in order to thereby vary the operation of the air pump 22.In particular, for example, the electronic computing device 32 can vary the speed of the air pump 22 and thereby the operation of the air pump 22 by controlling the air pump 22. Preferably, the air pump 22 is an air pump that differs from a gear pump, a turbine, or a rotary compressor, with the air pump 22 preferably being designed as a piston pump or a diaphragm pump. Very preferably, the electronic computing device 32 is designed to control the air pump 22 by controlling the air pump 22 by means of a closed control loop, thereby varying the operation of the air pump 22.

[0043] The device 10 has, for example, a Fig. 1 particularly schematically illustrated sensor device 36, by means of which, for example, the pressure of the compressed air in the line element 14, in particular in the length range L, and / or in the line element 24, also referred to as air pressure, can be detected, i.e. measured. Alternatively or additionally, for example, the quantity of air flowing through the line element 24 and / or the line element 14, in particular in the length range L, can be detected, i.e. measured, by means of the sensor device 36. In Fig. 1, an arrow 38 schematically illustrates that, for example, the sensor device 36 can provide a measurement signal, in particular an electrical one. The measurement signal characterizes, for example, the pressure measured by the sensor device 36 and / or the quantity measured by the sensor device 36. The electronic computing device 32 can receive the measurement signal. Subsequently, for example, the electronic computing device 32 can control, in particular regulate, the air pump 22 depending on the measurement signal, thus depending on the measured pressure and / or depending on the measured quantity, in order to thereby vary the operation of the air pump 22.

[0044] In the Fig. 1, the device 10 has an operating device 40 which has at least one operating element 42. In the embodiment shown in Fig. In the embodiment shown in Figure 1, the operating device 40 comprises a plurality of operating elements 42. The respective operating element 42 can be operated, for example, by a person in order to effect, i.e., make, at least one input, in particular at least two or more inputs, into the device 10. This means that the inputs effected or effectable by the person can be recorded by means of the operating elements 42, i.e., by means of the operating device 40. The electronic computing device 32 can control the air pump 22 depending on the inputs and thereby vary the operation of the air pump 22 depending on the inputs, so that the milk foam 26, in particular with regard to its quantity and / or quality, can be produced, i.e., manufactured, in different ways, depending on the inputs.For example, because the electronic computing device 32 controls the air pump 22 as a function of a first of the inputs, the milk foam 26 is produced with a first quantity and / or a first quality. In other words, for example, a first quantity and / or a first quality of the milk foam 26 is generated, i.e. produced, as a function of the first input. For example, because the electronic computing device 32 controls the air pump 22 as a function of a second of the inputs, the milk foam 26 is produced with a second quantity different from the first quantity and / or with a second quality different from the first quality. In other words, for example, a second quantity different from the first quantity and / or a second quality different from the first quality of the milk foam 26 is produced as a function of the second input.This allows the milk foam 26 to be produced automatically in different ways.

[0045] A method for operating the device 10 is described below. In particular, the device 10 can be operated in a frothing mode, also simply referred to as operating mode, normal operating mode, or normal operation, in which the device 10, as described above, provides or can provide the steam. In particular, it is conceivable that the frothing mode is carried out in the method, i.e. that the device 10 is operated in the frothing mode in which, as described above, the steam is generated and the device 10 provides the steam in order to thereby froth the milk, thus generating the milk foam. For example, the frothing mode can be carried out by a first operation carried out by a person, i.e., triggered or started.In other words, if, for example, the first operation of the operating device 40 by a person is detected by means of the operating device 40, the frothing mode is started depending on the detection of the first operation, i.e. the device is operated in the frothing mode.

[0046] As will be explained in more detail below, the device 10 can (also) be operated in a descaling mode, which can be triggered, i.e. started or activated, for example, by a second operation of the operating device 40 effected by a person, in particular one that is different from the first operation. In other words, if the second operation effected by a person, in particular one that is different from the first operation, is detected, for example, by the operating device 40, the descaling mode is carried out depending on the detection of the second operation, i.e. the device 10 is operated in the descaling mode. In the aforementioned method for operating the device 10, the device 10 is operated in the descaling mode.

[0047] Out of Fig. 1 shows that the device 10 has a container 44 provided in addition to the steam source 12, in which a liquid 46 can be received or is held. It is also apparent that the steam source 12 is provided in addition to the container 44. It can be seen that the steam source 12 is arranged outside the container 14, and the container 44 is arranged outside the steam source 12.

[0048] The device 10 also has a pump 48, also referred to as a liquid pump, by means of which the liquid 46 is to be conveyed, i.e., can be conveyed, from the container 44 into the vapor source 12. This means that the liquid 46 can be conveyed out of the container 44 and into the vapor source 12 by means of the pump 48. It can be seen that, for example, the pump 48 is provided in addition to the air pump 22, so that the air pump 22 is provided in addition to the pump 48. The pump 48 is arranged, for example, outside the air pump 22, and the air pump 22 is arranged, for example, outside the pump 48. For example, the pump 48 is electrically operated, thus an electrically operated pump 48.

[0049] Fig. Figure 2 shows the steam source 12 in a schematic sectional view. The steam source 12 has, for example, an inner circumferential surface 50, which defines, in particular directly, a receiving space 52 of the steam source 12. Thus, by means of the pump 48, the liquid 46 can be pumped from the container 44 into the receiving space 52 and thus into the steam source 12. Fig. 2 also shows an electrical heating element 54, which is, for example, a component of the steam source 12. The heating element 54 is arranged at least partially in the receiving space 52 and thus in the steam source 12. The liquid, which is conveyed, in particular by means of the pump 48, from the container 44 into the receiving space 52 and thus into the steam source 12, is in Fig. 2 is shown particularly schematically and also designated 46. It can be seen that the liquid 46 in the receiving space 52, thus in the vapor source 12, forms a level 56, also referred to as a fill level or level.

[0050] Preferably, in or in the frothing mode, water is used as the liquid 46, from which the aforementioned water vapor can be generated by means of and in the vapor source 12, which can then be provided by the vapor source 12. Shown in Fig. 2 is also a detection element 55 of the device 10, wherein the detection element 55 is arranged at least partially in the receiving space 52 and thus in the steam source 12. In the Fig.In the embodiment shown in Figure 2, the detection element 55 is designed as an electrode. A part of the detection element 55 arranged in the receiving space 52 is designated by T. It can be seen that the detection element 55 has a free end E arranged in the receiving space 52 and formed, for example, by the part T. By means of the detection element 55, a quantity of the liquid 46 pumped by the pump 48 from the container 44 into the vapor source 12, i.e., into the receiving space 52, can be detected. As the quantity of liquid 46 pumped by the pump 48 from the container 44 into the receiving space 52 increases, the level 56 of the liquid 46 in the receiving space 52 rises, in particular along a direction illustrated by a double arrow 57.If the level 56 and thus the liquid 46 in the receiving space 52 touches the detection element 55, in particular the end E, the detection element 55 thereby detects the liquid 46 received in the receiving space 52. In particular, it is provided that in the frothing mode, the conveying of the liquid 46 from the container 44 into the receiving space 52 by means of the pump 48 is terminated when the liquid 46 in the receiving space 52 is detected by means of the detection element 55, in particular when the level 56 or the liquid 46 in the receiving space 52 touches the end E.Thus, in particular in the frothing mode, it is provided that in the frothing mode, only such a large amount of liquid 46 is pumped from the container 44 into the receiving space 52 by means of the pump 48 that the level 56 rises, in particular along the direction, at most to a point S which, viewed along the direction, is spaced from an end E2 of the vapor source 12, which ends at the end E2 and has an edge R at the end E2. This means that in the frothing mode, the receiving space 52, and thus the vapor source 12, is not completely filled with the liquid 46. Instead, in the frothing mode, the receiving space 52 is only filled with the liquid 46 to such an extent that, viewed in particular along the direction (double arrow 57), an area B of the receiving space 52 adjoins the level 56, wherein the area B is free of the liquid 46, i.e., is not filled with the liquid 46.If, by means of the pump 48 and in particular in the frothing mode, the liquid 46 is filled from the container 44 into the vapor source 12, i.e., into the receiving space 52, such that the level 56 rises to the point S, at least a portion of the heating element 54 is located below the level 56. If the heating element 54 is then supplied with electrical energy, the liquid 46 in the receiving space 52 is heated by the heating element 54, whereby the water vapor is generated from the liquid 46 in the receiving space 52. The water vapor can initially collect in the region B and then be discharged from the region B and from the vapor source 12, whereby the vapor source 12 can provide the water vapor.

[0051] In order to be able to descale the steam source 12 particularly time- and cost-effectively and in particular (also) in the area B without having to disassemble the device 10, the device 10 is operated in the descaling mode during the method, in particular depending on the detection of the second operation. In the descaling mode, the liquid 46 is pumped from the container 44 into the steam source 12, i.e. into the receiving space 52, by means of the pump 48 in such a way that the steam source 12, and thus the receiving space 52, is completely filled with the liquid 46, thus up to the edge R or up to the end E2. Thus, in the descaling mode, the level 56 rises above the end E and the part T, with the level 56 rising in particular up to the edge R, i.e. up to the end E2.In particular, it is provided that in the descaling mode, the liquid 46 is pumped from the container 44 into the steam source 12, i.e., into the receiving space 52, by means of the pump 48 in such a targeted manner that the steam source 12, i.e., the receiving space 52, is overfilled with the liquid 46, so that the liquid 46 pumped into the steam source 12 by the pump 48 overflows the edge R and thus flows over the edge R and out of the steam source 12. This ensures that the steam source 12 is completely filled with the liquid 46.

[0052] Preferably, in the descaling mode, a descaler is used as the liquid 46, which is designed to dissolve limescale, so that by means of the descaler, limescale which may have accumulated on the inside of the steam source 12, i.e. on the inner circumferential surface 50, can be at least partially dissolved and thus at least partially removed from the inner circumferential surface 50.

[0053] It is preferably provided that in the descaling mode, after the steam source 12 has been completely filled or overfilled with the liquid 46, the receiving space 52, i.e. the steam source 12, is completely emptied with regard to the liquid 46 in order to thereby remove, for example, the descaler from the steam source 12.

[0054] The background to the method is in particular the following: If the steam source 12, designed for example as a boiler, is basically only filled with the liquid 46 up to the point S at which, for example, the end E is arranged, then for example only a second region B2 of the receiving space 52 and thus of the steam source 12 can be decalcified, extending along the direction from the point S and away from the end E2 and extending to a second end E3 of the steam source 12. It can be seen that the ends E2 and E3 of the steam source 12 or of the receiving space 52 are opposite one another along the direction (double arrow 57). The region B could then not be decalcified or not be decalcified effectively. However, this is now possible using the decalcification mode.

[0055] In conventional solutions, the steam source 12 is always filled with the liquid 46 only up to the point S and thus up to the end E, i.e. up to the electrode, in each operating mode of the device 12, which may be the case, for example, for logic or control reasons. Consequently, in order to advantageously descale the steam source 12, the device 10 would have to be disassembled. This can now be avoided by the method, since in the descaling mode the steam source 12 is completely filled with the liquid 46 or preferably even overfilled. Thus, complete descaling of the steam source 12, particularly its interior, is possible.

[0056] Preferably, the descaling mode is an automatic descaling program, which is carried out automatically, particularly after its activation, i.e., after its start. Thus, the steam source 12 can be descaled comprehensively, time-efficiently, and cost-effectively.

[0057] The edge R is, for example, an edge also referred to as the upper edge or is formed by an edge of the steam source 12, which edge is also referred to as the upper edge, for example, wherein the liquid 46 rises in the descaling mode at least up to the edge and preferably also beyond it, so that the steam source 12 is at least completely filled with the liquid 46 or even overfilled.

[0058] If, in the descaling mode, the descaler dissolves the limescale from the inner circumferential surface 50, for example, the limescale being dissolved in the descaler, carbon dioxide can be produced in the receiving space 52 through a chemical reaction, which can rise in the steam source 12, in particular along the upward direction, and for example expel the liquid 46 from the steam source 12. In order to ensure that the steam source 12 is completely filled with the liquid 46, for example in the descaling mode, the steam source 12 is completely filled or overfilled with the liquid 46 several times in succession. In other words, for example in the descaling mode, several filling processes are carried out, and thus at least or exactly two compared to two more, wherein the filling processes are preferably spaced apart from one another in time.This means that a first of the filling processes begins at a first start time and ends at a first end time, and a second of the filling processes begins at a second start time and ends at a second end time, wherein the second filling process follows the first filling process in time and wherein the first end time and the second start time are preferably spaced apart in time. Between the first end time and the second start time there is, for example, a waiting phase, also referred to as a holding phase, during which, for example, the pumping of the liquid 46 from the container 44 into the receiving space 52, i.e. into the steam source 12, by means of the pump 48, ceases continuously, i.e. without interruption and thus completely. During the respective filling process, the receiving space 52, i.e. the steam source 12, is completely filled with the liquid 46 or even overfilled.During the holding phase, as previously described, carbon dioxide can form in the receiving space 52, which can expel and thus remove at least a portion of the liquid 46 held in the steam source 12 from the steam source 12. Thus, during the holding phase, the steam source 12 may no longer be completely filled with the liquid 46. However, since the holding phase is followed by the second filling process, the steam source 12 is (re)filled completely with the liquid 46 during the second filling process, which advantageously allows the steam source 12 to be descaled.

[0059] In order to be able to reliably fill the steam source 12 completely with the liquid 46 or even overfill it, the device 10 has, for example, a flow sensor 58, also referred to as a flow meter or flow sensor, by means of which, for example, while the pump 48 is conveying the liquid 46 from the container 44 into the steam source 12 in the descaling mode and in particular during the respective filling process, a measured variable such as a volume flow or mass flow of the liquid 46 conveyed by means of the pump 48 in the descaling mode and flowing from the container 44 to and into the steam source 12 is detected, that is to say measured.In the descaling mode and in particular during or in the respective filling process, the liquid 46 is pumped from the container 44 into the steam source 12 by means of the pump 48 in a targeted manner depending on the measured variable measured by the flow sensor 58 in such a way that the steam source 12 is completely filled or overfilled with the liquid 46.

[0060] A particularly targeted removal or draining of the liquid 46 from the steam source 12, in particular after the steam source 12 has been completely filled with the liquid 46, is carried out, for example, in that in the descaling mode and in particular during an expulsion process following, for example, the second filling process, the liquid 46 in the steam source 12 is warmed, i.e. heated, by means of the heating element 54 to over 100 degrees Celsius and, for example, to at least or exactly 120 degrees Celsius, whereby steam is generated from the liquid 46 in the steam source 12 at a steam pressure by means of which steam the liquid 46 is expelled from the steam source 12 via at least or exactly one opening in the steam source 12 and thus drained away. Pumping the liquid 46 out of the steam source 12 by means of a separate drain pump and thus such a drain pump itself can thus be avoided.Thus, the steam source 12 can be descaled quickly and cost-effectively. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 1 501 398 B1

[0002]

Claims

[1] Method for operating a device (10) for frothing milk (20), in which the device (20) comprises: - a steam source (12) for providing steam for frothing the milk (29); - a container (44) provided in addition to the steam source (12) for holding a liquid (46); and - a pump (48) by means of which the liquid (46) is to be conveyed from the container (44) into the steam source (12); and characterized by that the device (10) is operated in a descaling mode in which the liquid (46) is conveyed from the container (44) into the steam source (12) in such a targeted manner by means of the pump (48) that the steam source (12) is completely filled with the liquid (46). [2] Method according to claim 1, characterized bythat in the descaling mode, the liquid (46) is conveyed from the container (44) into the steam source (12) several times in succession by means of the pump (48) in such a targeted manner that the steam source (12) is completely filled with the liquid (46) several times in succession. [3] Method according to claim 1 or 2, characterized by that in the descaling mode, the liquid (46) is pumped from the container (44) into the steam source (12) by means of the pump (48) in such a way that the steam source (12) is overfilled with the liquid (46). [4] Method according to claim 3, characterized by that in the descaling mode, the liquid (46) is pumped from the container (44) into the steam source (12) several times in succession by means of the pump (48) in such a targeted manner that the steam source (12) is overfilled with the liquid (46) several times in succession. [5] Method according to one of the preceding claims, characterized bythat in at least one operating mode of the device (10) which is different from the descaling mode and is provided for providing the steam, in particular in all operating modes of the device (10) which are different from the descaling mode and are provided for providing the steam, a conveying of liquid (46) from the container (44) into the steam source (12) which is deliberately effected by means of the pump (48) in such a way that the steam source (12) is completely filled with the liquid (46) from the container (44). [6] Method according to one of the preceding claims, characterized byin that the device (10) has at least one detection element (55) for detecting a quantity of the liquid (46) conveyed by means of the pump (48) from the container (44) into the steam source (12) and received in the steam source (12), wherein in the descaling mode the liquid (46) is conveyed from the container (44) into the steam source (12) in a targeted manner by means of the pump (48) in such a way that a level (56) of the liquid (46) in the steam source (12) formed by the liquid (46) conveyed by means of the pump (48) from the container (44) into the steam source (12) rises over at least a part (T) of the detection element (55) and the steam source (12) is completely filled with the liquid (46). [7] Method according to one of the preceding claims, characterized by that in the descaling mode: - while the pump (48) conveys the liquid (46) from the container (44) into the steam source (12), a measurement value is recorded by means of a flow sensor (58), which characterises a flow of the liquid (46) flowing from the container (44) into the steam source (12) by means of the pump (48) and from the container (44) to the steam source (12); and - by means of the pump (48), the liquid (46) is conveyed from the container (44) into the steam source (12) in a targeted manner as a function of the measured variable detected by the flow sensor (58) in such a way that the steam source (12) is completely filled with the liquid (46). [8] Method according to claim 6 and any one of claims 1 to 5, characterized bythat in the descaling mode, from a point in time at which the level (56) of the liquid (46) in the steam source (12) is at the same height as the part (T) of the detection element (55) and as a result the detection element (55) detects the level (56) of the liquid (46) in the steam source (12), the pump (48) is operated for a further predetermined period of time, whereby the liquid (46) is conveyed from the container (44) into the steam source (12) by means of the pump (48) during the period of time and the level (56) rises at least above the part (T) of the detection element (55). [9] Method according to claim 8, characterized by in the descaling mode, the pump (48) conveys the liquid (46) from the container (44) into the steam source (12) without a measurement variable being detected by means of a flow sensor (58) which characterizes a flow of the liquid (46) flowing from the container (44) into the steam source (12) by means of the pump (48). [10] Method according to claim 8 or 9, characterized by that the time period is stored in a data memory of an electronic computing device. [11] Method according to one of claims 8 to 10, characterized by that the time period for each descaling mode execution is constant. [12] Method according to one of the preceding claims, characterized bythat after the steam source (12) has been completely filled with the liquid (46) in the descaling mode, the liquid (46) is drained from the steam source (12) in the descaling mode, whereby the steam source (12) is at least predominantly, in particular completely, emptied in the descaling mode, whereupon in the descaling mode the liquid (46) or another liquid is conveyed from the container (44) into the steam source (12) in a targeted manner by means of the pump (48) in such a way that the steam source (12) is completely filled with the liquid (46) or the other liquid. [13] Method according to claim 12, characterized bythat after the steam source (12) has been completely filled with the liquid (46) or the other liquid in the descaling mode, the liquid (46) or the other liquid is discharged from the steam source (12) in such a way that the liquid or the other liquid in the steam source is heated to over 100 degrees Celsius, whereby steam is generated from the liquid (46) or the other liquid in the steam source (12) at a steam pressure by means of which the liquid (46) or the other liquid is expelled from the steam source (12) via at least or exactly one opening of the steam source (12). [14] Method according to one of the preceding claims, characterized by that the device (10) is operated as a component of a beverage maker, in particular a hot beverage maker and especially a coffee machine. [15] Device (10) for frothing milk (20), wherein the device (10) is designed to carry out a method according to one of the preceding claims.

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