Method and apparatus for producing temperature-controlled milk foam and / or milk

Abstract

A method for selectively producing cold, warm or hot milk foam and / or milk, comprising the steps of: providing at least one container (10) for storing milk to be frothed; providing fluids and fluid lines (22); feeding a predeterminable amount of milk to be frothed by a pump (16) through a line system (12) including a milk suction line (14) between the at least one container (10) and the pump (16) and an outlet line (30) between the pump (16) and at least one outlet (32); and feeding a milk / air mixture upstream of the pump (16). The method comprises the steps of potentially supplying air to the milk suction line (14) via an air flow regulator (26) which can be arranged in the air supply line (24) to produce a mixture, conveying the milk / air mixture or milk through a heating element (39) designed as a flow heater and arranged in the outlet line (30) and in the form of a thick-film heating element (40), producing milk foam from the milk / air mixture by means of a squeezing device (50) and discharging the milk foam or milk at at least one outlet (32). According to the method, the thick-film heating element (40) is permanently heated to a predeterminable temperature and a fluid is applied at least partially to the line system (12) after each discharge of the milk foam or milk. The invention also relates to an apparatus for selectively producing cold, warm or hot milk foam and / or milk according to the above-mentioned method.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for producing temperature-controlled milk foam and / or milk, specifically to a method and an apparatus for selectively producing cold, warm or hot milk foam or milk.

Background Art

[0002] Methods and apparatuses for selectively producing cold, warm or hot milk and / or milk foam are known, especially in combination with beverage makers, such as coffee machines. Depending on the selected beverage and / or coffee specialty, such as cappuccino, latte macchiato, caffe latte, chocolate or tea, not only the amount but also the temperature of the milk and / or milk foam to be supplied is different. To produce milk foam, milk is generally sucked up from a container by a pump, mixed with air or gas supplied between the flow paths to the outlet, and then warmed as a milk / air mixture to a determinable temperature by a heating element and processed into foam. For reasons of shelf life and hygiene, milk is stored in a cool place, especially at 3°C to 7°C. The heating element by which the milk or milk foam is temperature-controlled and possibly produced can be a flow heater, and various types are suitable.

[0003] Generally, there are various methods for making milk foam. For example, air, gas, or high-temperature steam can be mixed with milk in a foam unit, and the generated turbulent flow can foam the milk to form a more or less stable foam. Foaming can also be performed by mechanical stirring or a squeezing device.

[0004] In known methods and apparatus, different flow paths are often provided in parallel, depending on the selected temperature of the milk and the milk / air mixture or milk foam. Cold milk is delivered to the outlet via the first flow path, while warm milk is delivered via the second flow path, often containing a continuous flow heating element. However, such parallel flow paths not only impose complex line systems and numerous switchable parts, but also present problems in terms of contamination, bacterial growth, and cleaning.

[0005] In known systems with only one milk line, the milk, milk-air mixture, or milk foam must always pass through the heating element, regardless of its temperature. The drawback of such systems is that if cold milk or cold milk foam is supplied immediately after hot milk or hot milk foam has been dispensed, the cold milk or cold milk foam will be heated by the residual heat of the heating element, even if the heating element is switched off. Thus, it is known that a switched-off airflow heating element is at least partially cooled, and in some cases washed, by the flow of cold milk or rinse fluid.

[0006] International Publication 2017 / 155403 describes an apparatus for producing hot or cold milk foam that can be served continuously in a relatively short time. Here, a flow-through heating unit is provided that can be switched between an active and an inactive state. The flow-through heating unit is designed as a thick-film heating element with a small thermal mass. The thick-film heating element is precisely defined with respect to its thermal behavior to account for the thermal inertia immediately after switching the thick-film heating element on or off. In particular, the thermal behavior immediately after switching off is defined, i.e., when the heating unit is turned on to produce warm or hot milk foam and then immediately turned off to provide cold or only slightly heated milk foam. In this way, the thick-film heating element is set so that a small amount of milk, about 40-60 ml, with a temperature of about 7°C or less in the frothed state, is heated to a temperature of less than 20°C at the fluid inlet of the sealed milk line as it flows through the flow-through heating unit in an inactive state for less than 10 seconds. Thus, it is not possible to actually serve a cold beverage, as the temperature should be less than 10°C, especially less than 7°C, during the initial extraction. However, even though a large amount of milk, 60 to 80 ml, is needed to make a beverage, the first extraction is usually too hot, and a cold beverage can only be served with the second extraction. Therefore, the change between a soft drink and a cold drink can often only be achieved by rinsing extensively with cold milk, which makes the system unprofitable and presents problems with milk skin formation.

[0007] Generally, when a flow-through heating unit designed as a thick-film heating element is switched on, the heating unit heats up first, and then, with a certain delay, the sealed fluid channel also reaches the desired temperature. This temperature is critical for heating the milk foam flowing through the fluid channel. Even if the thermal mass of the thick-film heating element is small and the heating profile is steep, the heating of the milk foam follows a flat heating curve. In the case of so-called overshoot fluid systems, localized overheating can occur during the heating phase, which is detrimental in various ways to the food and the deposits that form in the fluid channel during overheating.

[0008] Flow-through heating units designed as thick-film heating elements for temperature-controlled milk foam production are already known. Thick-film heating elements are generally layered composites consisting of a carrier substrate, such as a metal element, covered with a dielectric coating, such as a glass-ceramic layer, and supporting a conductive track made of a conductive material that functions as an insulator on the one hand and generates heat in the active state on the other. The generated heat can be transferred to a fluid flowing through a fluid channel formed on the thick-film heating element, such as a meandering or spiral fluid channel. In particular, the size, shape, and / or electrical properties of the thick-film heating element can be adapted to the respective work or use location. Furthermore, temperature sensors and other functions can be incorporated. Thick-film heating elements are characterized by a steep temperature or heating profile, and therefore by very fast and short response operation; above all, thick-film heating elements are not used in standby mode. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] In contrast to well-known methods and apparatuses, the present invention makes it possible to produce cold, warm, or hot milk or milk foam in a simple series of steps and in an apparatus of simple structure, that is, without complex switching of parallel channels and components, and without delays caused by selectively switching heating units on or off.

[0010] The problem is solved through the features of the independent clause. Advantageous further advanced embodiments of the present invention are shown in the dependent clauses and figures. [Means for solving the problem]

[0011] A method is provided for selectively producing cold, warm, or hot milk foam and / or milk according to the present invention, the method being: A step of providing at least one container for storing milk to be frothed, A process for providing fluids and fluid lines, A process of supplying a predetermined amount of milk to be frothed by a pump through a line system comprising a milk suction line between at least one container and a pump, and a single outlet line between the pump and at least one outlet, A step of supplying air to the milk suction line via an airflow regulator to create a mixture of milk and air upstream of the pump, A process of supplying milk and air mixture or milk through a heating element located in the outlet line and designed as a flow heater in the form of a thick film heating element, The process includes dispensing milk foam or milk from at least one outlet.

[0012] The method is characterized by the fact that a thick-film heating element is permanently heated to a predetermined temperature, and after the dispensing of milk foam or milk, the fluid is applied at least partially to the line system. In particular, the fluid is applied to the system outside the cooling area. Water, especially filtered water, is suitable as the fluid.

[0013] Surprisingly, the standby mode of a flow heater designed as a thick-film heating element has been shown to be highly advantageous, in contrast to known methods of selectively producing cold, warm, or hot milk foam by only a single flow path downstream of the pump, i.e., a simple line system. This is in contrast to the conventional operating modes of flow heaters designed as thick-film heating elements, which are designed to avoid delays and prolonged response times when switching between active and inactive states, i.e., in standby mode. Standby mode means that when the apparatus for producing temperature-controlled milk foam or milk is operating, the thick-film heating element is permanently temperature-controlled at a predetermined temperature.

[0014] In standby mode, i.e., the active state of a switchable heating unit, the significantly shorter heating phase and greater reliability in further temperature increases compared to the case of a switched-off and cooled heating unit are advantages. Furthermore, time delays in temperature setting of the fluid flow path can be almost avoided. Even in heating units designed as thick-film heating elements with low thermal mass and very steep heating profiles, the heating phase is shortened, but it still takes a certain amount of time for the flowing fluid to heat to the desired temperature. This is particularly disadvantageous when heating only small amounts of milk or milk foam. In some specialty coffees, only small amounts of temperature-controlled milk or milk foam are required, so slow heating can prevent the small amount of milk or milk foam from reaching the required temperature. A small cappuccino with about 80 ml of milk foam, or a so-called cortado with even less milk foam, may end up too cold for this reason. The slower and longer response time of the heating device used to heat milk and / or milk foam is particularly disadvantageous when heating small amounts of milk foam or milk.

[0015] According to one embodiment of this method, a fluid, preferably water, is discharged from the line system via a manifold valve only before milk foam and / or milk is dispensed at at least one outlet provided for this purpose. Thus, the line system, and in particular the heating element designed as a thick-film heating element, is exposed to the fluid between the two milk foam and / or milk dispensings. This proves to be advantageous in many respects, as will be discussed later.

[0016] According to the present invention, the thick-film heating element remains permanently active, so it does not need to be switched on or off as needed. Preferably, the thick-film heating element is heated to a temperature between 60°C and 70°C. This means that the fluid flow path provided in the thick-film heating element is also permanently at the corresponding high temperature.

[0017] If it is necessary to further increase the temperature of the thick-film heating element to produce hot milk foam or hot milk, only a relatively small temperature difference needs to be raised. This temperature difference is, for example, about 4°C to 7°C. According to the preferred embodiment, this small temperature difference can be overcome quickly and safely. Overshoot in the control of the heating unit, and consequently localized overheating caused by the temperature of the thick-film heating element, can be avoided by overcoming this small temperature difference.

[0018] According to the present invention, in order to produce temperature-controlled milk foam and / or milk, cooled milk, particularly at a temperature of 3°C to 7°C, can be conveyed through a line system via a milk suction line by a pump. In order to bring the temperature of the milk foam and / or milk at the distribution point or outlet to about 64°C to 68°C, the cooling of the milk foam and / or milk in the flow path up to the distribution point must also be taken into consideration, although the temperature of the heating element should be about 70°C to 75°C.

[0019] Previously, systems were known in which heating elements, in the form of thick-film heating elements, had to be switched from an inactive or switched-off state to an active or switched-on state to control the temperature of milk foam or milk, thereby heating the heating element according to a heating profile that started at a low temperature. During this heating stage, localized overheating can occur. This has been observed in well-known heating devices, where, after a rapid change in the input variable, the output variable first exceeds the set value, and only then does it exceed the desired value of the initial output variable. When the thick-film heating element is switched on and heated, the temperature may rise slightly above the actual set temperature, which can cause localized overheating. This overheating adversely affects the milk foam or milk being heated, particularly causing the corresponding denaturation of milk proteins, resulting in the formation of precipitates.

[0020] According to one embodiment, by applying a fluid, such as tap water, to the line system each time after dispensing milk foam and / or milk, at least sections of the line system and components placed on it can be cooled or heated, particularly depending on the temperature of the fluid supplied to the milk suction line. However, at least sections of the line system, particularly the outlet line and at least one outlet itself, are also heated, as they are heated by the heat transmitted by the heating element, regardless of the temperature of the supplied fluid. The heated section of the line and components placed on it have proven to be very advantageous because they can supply milk foam or heated milk heated by the heating element at at least one outlet without significant cooling.

[0021] On the other hand, if cold milk foam or cold milk is requested by the user, for example, a method according to one embodiment of the present invention involves flushing a heating element, designed in the form of a line system and a thick-film heating element, with a fluid so that the thick-film heating element is cooled by the fluid flowing over it to a temperature preferably corresponding to the cooling temperature in the cooling device, i.e., 7°C or lower, for a period of more than 10 seconds. In particular, the goal may be to cool the fluid to a temperature of 4°C or lower to greatly compensate for the heating in the flow path and the element placed thereon. In one embodiment, water is used as the fluid, which may be supplied, for example, by a municipal supply network. It should be noted that so-called tap water has different temperatures depending on the environment and season, which is referred to as the water inlet temperature. Depending on the season, the temperature of tap water is between 10°C and 25°C.

[0022] In a preferred embodiment, a fluid, such as tap water supplied via a supply network, can be cooled by a cooling unit. The temperature of milk cooled and stored in the cooling device can serve as an orientation for the set cooling temperature. The cooling of milk or a portion of the device can be designed to cool the fluid to 7°C or below. Alternatively, the fluid can be cooled by another cooling unit, for example, attached to the fluid line. Thus, it is possible to avoid the initial cold beverage being at a temperature higher than the desired temperature. Since the cooled fluid can be cooled, for example, via a cooling unit located in the supply fluid line, it is possible to rinse the line system with cold fluid even if the fluid in the fluid line itself is already heated at a high ambient temperature. One possibility for efficient temperature control of the fluid is the use of latent heat accumulators using phase change materials (PCMs). These are well known and can be used in various forms. Phase change materials can be used for heat storage, cold storage, and temperature peak suppression. Because phase change materials have a high storage volume, the latent heat energy stored during the phase change can be utilized for thermal management. PCM technology utilizes the effect that, for example, during a phase transition from solid to liquid, the temperature remains constant as long as both aggregated states exist simultaneously. The potentially stored energy can be reused in the reverse process. The melting temperature of the PCM, particularly the material, can be selected according to the usage conditions. For example, an aqueous salt solution is suitable for cooling, allowing the phase-change material to be used in a sealed container, bound to a matrix and / or carrier structure, and / or microencapsulated.

[0023] Therefore, by using PCM technology, further cooling of fluids or tap water can be achieved. Heating elements designed as thick-film heating elements can not only cool to the temperature of tap water, i.e., from 10°C to 25°C, but also cool in such a way that, when switched on, the temperature of milk and / or milk foam at the outlet reaches below 7°C more rapidly. Corresponding cooling designs can achieve temperatures in the range of 4°C to 7°C, particularly below 4°C.

[0024] It is particularly advantageous to use PCM technology for cooling stored milk in order to also cool the fluid or tap water used for rinsing and application.

[0025] Flushing of the line system with fluid occurs at one position of a valve device arranged in the outlet line and preferably designed as a manifold valve, and the fluid can be discharged from the line system. At another position of the manifold valve, the fluid can be introduced into the circuit. The manifold valve can be switched by a control unit, whereby the control unit can control further components. The control unit can be designed to control the temperature-controlled milk foam and / or the process for producing milk in response to an instruction from the user.

[0026] According to the present invention, there is proposed an apparatus for producing cold, warm, and hot milk foam and / or milk according to the method of the present invention. The apparatus comprises a line system consisting of at least one container in which the milk to be foamed is stored, a pump, a milk suction line through which the at least one container can be connected to the pump, and a single outlet line through which the pump can be connected to at least one outlet. Further, a fluid line through which fluid can be supplied to the line system is also provided. An air flow regulator is also included, by which air can be metered and supplied to the milk suction line via the air supply line at the inlet point, a heating element designed as a flow heater is arranged in the outlet line, and a throttle device designed as a thick film heating element can be arranged in the outlet line downstream of the pump.

[0027] To produce milk foam from a milk / air mixture, a throttling device can be arranged in the outlet line downstream of the pump, preferably downstream of a heating element designed as a thick-film heating element. The throttling device can be designed as a fixed or adjustable nozzle or orifice and, in particular, consists of a constriction with an adjustable cross-sectional area of the flow. The throttling device is set to generate a backpressure that acts advantageously on the heating element designed as a thick-film heating element. The generated backpressure counteracts the expansion of the bubbles in the milk and air mixture that occurs with the temperature increase. This prevents the formation of large bubbles that not only reduce the quality and stability of the milk foam but also have an adverse effect on heat conduction because air has a low thermal conductivity.

[0028] In one embodiment of the device, the heating element in the form of a thick-film heating element has an electrical resistor mounted on a carrier and a fluid flow path in contact with the heating element.

[0029] Advantageously, the device can be arranged at least partially within a cooling device.

[0030] Furthermore, the device can include a conductance sensor that is installed to determine the conductance of the medium within the line system. The conductance value can be used to determine, in particular, which medium among milk, a milk and air mixture, a fluid, or air is involved.

[0031] According to one embodiment, a manifold valve is provided in the discharge line, and this manifold valve selectively connects the discharge line to an outlet for discharging the fluid, a circuit line for circulating the fluid through the line system, or at least one outlet to which the milk foam and / or milk is distributed. The at least one outlet can be designed as an outlet nozzle. The line section between the manifold valve and the at least one outlet can be dimensioned to have a small filling volume of, for example, about 2 - 3 ml.

[0032] In one embodiment of the present invention, the air supply line is further provided with a first check valve and a second check valve. Between the first check valve and the second check valve, fluid can be supplied to the air supply line via the first valve R1. Thus, the first valve R1, which is adjustable by the control unit, is provided in the fluid line in the flow path to the air supply line. The first check valve and the second check valve are preferably switchable independently of each other.

[0033] Preferably, the first and second check valves are designed as direct-closing check valves and can be positioned perpendicular to the air supply line, allowing the flow to pass from top to bottom. Direct-closing check valves generally consist of a closing element that is pressed against its seat by the medium and / or gravity. Delays and vibrations during the closing process can be reduced. Thus, the vertical orientation of the first and second check valves in the air supply line allows for accurate doses of air to be achieved by an airflow regulator positioned within the air supply line. With this configuration, the supplied fluid can also be used to flush at least a portion of the air supply line as needed, which is advantageous with respect to accurate measurement of the air volume.

[0034] Alternatively or additionally, a fluid may be supplied to the milk suction line via a fluid line to broadly apply or flush a section of the line system carrying milk or a mixture of milk and air or milk foam with the fluid. A second valve R2, adjustable by a control device, is provided in the fluid line to control the introduction of the fluid into the milk suction line.

[0035] In particular, the fluid is water and can be supplied via water pipes. Depending on the ambient temperature and season, the water introduced into the water pipes may already be at a high temperature; for example, in summer, water at 20°C or higher is initially drawn from the water pipes. In one embodiment of the present invention, a cooling unit can be provided to cool the fluid to a low temperature, particularly 7°C or lower.

[0036] By the method and apparatus according to the present invention for selectively producing cold, warm, or hot milk foam and / or milk, a heating element in the form of a thick-film heating element can be kept active at all times, at least when the beverage maker connected to it is also in operation. Since the flow heater in the form of a thick-film heating element and the line system are exposed to the fluid between two milk or milk foam distributions, the thick-film heating element is kept at a high temperature in standby mode at all times, and only short heating or cooling phases of the thick-film heating element should be considered as needed.

[0037] One embodiment of the present invention will be described in more detail below with reference to the drawings. [Brief explanation of the drawing]

[0038] [Figure 1] Figure 1 schematically shows an apparatus according to the present invention for selectively producing cold, warm, or hot milk foam and / or milk. [Modes for carrying out the invention]

[0039] A schematic embodiment of the apparatus 1 according to the present invention, shown in Figure 1, is designed to produce cold, warm, or hot milk foam and / or milk. The milk to be frothed or other liquid to be frothed is stored in a container 10, preferably located within a cooling device 2. Preferably, the cooling device 2 can be designed to at least partially house the apparatus 1 therein. Since various types of milk are available today, multiple storage containers 10 can be provided, each container able to store one type of milk. A milk suction line 14, included in the line system 12, leads from at least one container 10 to the suction side of a pump 16 in order to draw milk from at least one container 10 when a correspondingly provided shut-off valve 11 opens the flow path.

[0040] In the illustrated embodiment, a conductance sensor 18 is located in the milk suction line 14 and is configured to determine the type of medium being transported in the milk suction line 14, i.e., milk, fluid, water, rinse liquid, or air, by measuring the conductance.

[0041] Furthermore, a valve 20 is positioned in the milk suction line 14, which opens the milk suction line 14 toward the suction side of the pump 16 and is designed as a backflow prevention valve.

[0042] Upstream of valve 20, a fluid line 22 opens into a milk suction line 14, through which fluid can be supplied. In particular, the fluid is water, preferably applied to the line system 12 at a constant temperature. By application, or application, means both filling and holding, and rinsing. The fluid, which can be introduced into the milk suction line 14 by fluid line 22 and shut off by the second valve R2, can preferably be introduced into the apparatus 1 in a manner controlled by a control unit (not shown) between two distributions of milk and / or milk foam, and in particular, remains there until a new distribution of milk foam and / or milk is required.

[0043] On the suction side of pump 16, the line system 12 also includes an air supply line 24 for introducing metered and controlled air into the milk suction line 14 at the inlet point 25. For this purpose, an airflow regulator 26, for example in the form of a proportional valve, is provided. This allows a precisely determinable amount of air to be introduced into the line system 12 or mixed with the milk being transported, so that the mixture of milk and air is present in the milk suction line 14 downstream of the inlet point 25, and that mixture is transported by pump 16.

[0044] Figure 1 shows that a first check valve 27 and a second check valve 28 are provided in the air supply line 24. The first check valve 27 and / or the second check valve 28 can be designed as direct-close check valves and are positioned vertically such that the force of gravity acting on the sealed closing element supports the opening of the first check valve 27 and / or the second check valve 28. Thus, the air supply line 24 will open even if the generated negative pressure is not at all sufficient for air intake.

[0045] A portion of the fluid line 22 opens between a first check valve 27 and a second check valve 28. When the first valve R1 is open in this portion, the fluid is introduced into the air supply line 24, and thus this portion of the line system 12 can also be flushed. A cooling unit 60 may be provided to cool the fluid that can be introduced into the line system by the fluid line 22. The cooling unit 60 may be designed as a latent heat accumulator having a phase change material (PCM). The PCM technology used can cool tap water supplied by the supply network to a temperature of 7°C or lower. Thus, the temperature of the fluid, in particular the tap water, can be controlled independently of the ambient temperature and the temperature of the tap water in the supply network. Alternatively, to cool the fluid in this manner, the cooling system 2 for the milk and components of the apparatus 1 may be designed as a latent heat accumulator using a PCM.

[0046] On its pressure side, the pump 16 is connected to an outlet 32 ​​that can discharge processed milk and / or processed milk foam via a single outlet line 30. Upstream of the outlet 32, a manifold valve 33 is positioned to selectively supply flow in the direction of the outlet 32 ​​or the drain 35. Further positions of the manifold valve 33 can also allow for flushing of the circuit.

[0047] Downstream of the pump 16, a flow heater is provided in the outlet line 30, which is a heating element 39 designed as a thick-film heating element 40. The heating element 39 consists of an electrically heated resistor installed on a carrier and a fluid channel through which the fluid to be heated flows. According to the present invention, the heating element 39 designed as a thick-film heating element 40 is permanently active and is therefore always heated to a temperature of, for example, about 60°C to 70°C. Furthermore, it is provided that the fluid is applied to the line system 12 between two dispensings at the milk foam and / or milk dispensing port 32. The application of the fluid fills the line system 12 with the fluid at least partially between the two milk foam and / or milk dispensings. Filling the line system 12 and the thick-film heating element 40 reduces the risk of overheating and allows heating of the portion of the outlet line 30 extending from the thick-film heating element 40 and the components connected thereto, such as the outlet 32.

[0048] Furthermore, the squeezing device 50 is positioned downstream of the outlet line 30, particularly the thick-film heating element 40, and this squeezing device is preferably adjustable by a control unit (not shown). The squeezing device 50 can have a positive effect on the stability and quality of the milk foam produced.

[0049] Each time the temperature-controlled milk foam and / or milk is drawn out of outlet 32, the fluid is discharged from the line system 12 via the manifold valve 33. To produce warm milk foam and / or warm milk, the milk / air mixture or milk is passed through the heated heating element 39 and the heated portion of the outlet line 30. For example, to produce hot milk foam and / or milk, the temperature of the thick-film heating element 40 is raised by a small temperature difference so that the milk / air mixture and / or milk flowing through it is heated to a temperature in the range of approximately 64°C to 68°C at outlet 32. Cooling of the milk foam and / or milk in the line system 12 is significantly reduced by the temperature-controlled flow path. In this way, even small amounts of milk / air mixture or milk can be brought to the appropriate temperature in a very short time.

[0050] To produce cold milk foam and / or cold milk, the apparatus and method according to the present invention does not require switching off the heating element 39, which is designed as a thick film heating element 40, and considering its thermal behavior. Instead, when the manifold valve 33 is open, the fluid located in the line system is discharged, and the cold fluid or fluid cooled by the cooling unit 60 is drawn by the pump 16 through the fluid line 22 to the line system 12, where it is delivered, and the cold fluid flowing through the fluid passage of the thick film heating element 40 cools this fluid passage to such an extent that the subsequent milk / air mixture or milk is not heated or is only slightly heated, even though the thick film heating element 40 is switched on. [Prior art documents] [Patent Documents]

[0051] [Patent Document 1] International Publication No. 2017 / 155403

Claims

1. A method for selectively producing cold, warm, or hot milk foam and / or milk, A step of providing at least one container (10) for storing milk to be frothed, A process of supplying a predetermined amount of frothed milk by the pump (16) through a line system (12) including a milk suction line (14) between at least one container (10) and a pump (16), and a single outlet line (30) between the pump (16) and at least one outlet (32), A step of providing a fluid line (22) through which a fluid can be applied to the line system (12), A step of potentially supplying air to the milk suction line (14) via an airflow regulator (26) that can be positioned in the air supply line (24) in order to generate a milk / air mixture upstream of the pump (16), A process of conveying a milk / air mixture or milk through a heating element (39), which is designed as a flow heater, positioned in the outlet line (30), and is in the form of a thick-film heating element (40), A step of generating milk foam from the milk / air mixture using a squeezing device (50), The process of dispensing the milk foam or milk at the at least one outlet (32) and Equipped with, The manufacturing method is characterized in that the thick-film heating element (40) is permanently heated to a predetermined temperature, and each time the milk foam or milk is dispensed, the fluid is applied at least partially to the line system (12).

2. A method for selectively producing cold, warm, or hot milk foam and / or milk according to claim 1, characterized in that the fluid is transported from the line system (12) via a manifold valve (33) before the milk foam or milk is discharged at the outlet (32).

3. A method for selectively producing cold, warm, or hot milk foam and / or milk according to claim 1 or 2, characterized in that the fluid is water.

4. A method for selectively producing cold, warm, or hot milk foam and / or milk according to any one of claims 1 to 3, characterized in that the thick-film heating element (40) is permanently heated to a temperature between 60°C and 70°C.

5. A method for selectively producing cold, warm, or hot milk foam and / or milk according to claim 4, characterized in that the temperature of the thick-film heating element (40) is raised by 4°C to 7°C in order to produce hot milk foam and / or milk.

6. A method for selectively producing cold, warm, or hot milk foam and / or milk according to any one of claims 1 to 5, characterized in that the line system (12) and the thick film heating element (40) are rinsed with a fluid, and the thick film heating element (40) is cooled to a temperature of 7°C or less by the fluid flowing therethrough over a period of time exceeding 10 seconds.

7. A method for selectively producing cold, warm, or hot milk foam and / or milk according to claim 6, characterized in that the supplyable fluid has a temperature of 7°C or lower.

8. A method for selectively producing cold, warm, or hot milk foam and / or milk according to claim 7, characterized in that the supplyable fluid is cooled to a temperature of 7°C or less by a cooling unit (60) designed as a latent heat accumulator having a phase change material.

9. A method for selectively producing cold, warm, or hot milk foam and / or milk according to any one of claims 1 to 8, characterized in that a control unit controls the method in accordance with instructions generated by a user.

10. Apparatus (1) for selectively producing cold, warm, or hot milk foam and / or milk according to the method described in any one of claims 1 to 9, A container (10) in which milk to be frothed is stored, Pump (16) and Line system (12), A milk suction line (14) through which at least one container (10) can be connected to the pump (16), An outlet line (30) through which the pump (16) is connected to at least one outlet (32), A line system (12) having, A fluid line (22) through which a fluid can be applied to the line system (12), An air flow regulator (26) is provided, which meters and transports air into the milk suction line (14) at the inlet point (25) via the air supply line (24). The outlet line (30) is positioned and is designed as a thick film heating element (40), and is a heating element (39) designed as a flow heater, A throttle device (50) that can be positioned downstream of the pump (16) in the outlet line (30) and A device equipped with the following features.

11. Apparatus (1) for selectively producing cold, warm, or hot milk foam and / or milk, according to claim 10, characterized in that the thick-film heating element (40) has an electrical resistor mounted on a support and a fluid channel in contact with the heating element (39).

12. Apparatus (1) for producing cold, warm, or hot milk foam and / or milk according to claim 10 or 11, characterized in that the apparatus (1) can be at least partially located within a cooling device (2).

13. Apparatus (1) for selectively producing cold, warm, or hot milk foam and / or milk according to any one of claims 10 to 12, characterized in that it is provided with a latent heat storage unit having a phase change material, which is arranged to cool the milk and / or fluid to a temperature of 7°C or less.

14. Apparatus (1) for selectively producing cold, warm, or hot milk foam and / or milk according to any one of claims 10 to 13, characterized in that a conductance sensor (18) for determining the conductance of a medium in the line system is provided.

15. Apparatus (1) for selectively producing cold, warm, or hot milk foam and / or milk according to any one of claims 10 to 14, characterized in that a manifold valve (33) is provided in the outlet line (30) and selectively connects the outlet line (30) to a drain (35) for discharging the fluid, a circuit line for circulating the fluid through the line system, or at least one outlet (32) from which milk foam or milk is discharged.

16. Apparatus (1) for selectively producing cold, warm, or hot milk foam and / or milk according to any one of claims 10 to 15, wherein a first check valve (27) and a second check valve (28) are arranged vertically within the air supply line (24) and such that the flow passes through them from top to bottom, and these are designed as check valves that close directly, and the fluid is introduced into the air supply line (24) between the first check valve (27) and the second check valve (28) via a valve R2.

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