阅读说明：本技术 用于制备热饮品的咖啡机 (Coffee machine for preparing hot drinks ) 是由 F·J·P·埃平 于 2019-07-24 设计创作，主要内容包括：用于制备热饮品的咖啡机(1),具有用于动态热管理的加热系统,包括壳体框架(2),其中容纳：水模块(100),用于提供冲泡水,且包括第一加热设备(120),第一加热设备包括具有淡水入口(12)的热水器(121)和用于提供加热到第一温度T<Sub>1</Sub>的水的第一加热元件(123)；及,冲泡模块(200),由此冲泡模块(200)具有用于用冲泡水冲泡预定量的咖啡的冲泡设备(220)和用于分配经冲泡的咖啡的分配单元(230),及安排在冲泡水供给管线(260)中的第二加热设备(250),从而将经加热到第一温度T<Sub>1</Sub>的水加热到第二温度T<Sub>2</Sub>。咖啡机规定容纳在该冲泡模块(200)中的第二加热设备(250)是被设计为连续流动加热器的厚膜加热器(252)。(Coffee machine (1) for preparing hot drinks, with a heating system for dynamic thermal management, comprising a housing frame (2) in which are housed: a water module (100) for providing brewing water and comprising a first heating device (120) comprising a boiler (121) having a fresh water inlet (12) and for providing heating to a first temperature T 1 A first heating element (123) of the water; and, a brewing module (200), whereby the brewing module (200) has a brewing device (220) for brewing a predetermined amount of coffee with brewing water and a dispensing unit (230) for dispensing the brewed coffee, and a second heating device (250) arranged in a brewing water supply line (260) to be heated to a first temperature T 1 Is heated toSecond temperature T 2 . The coffee machine provides that the second heating device (250) housed in the brewing module (200) is a thick film heater (252) designed as a continuous flow heater.)

1. A coffee machine (1) for preparing a hot drink comprises

A housing frame (2) in which are housed:

-a water module (100) for providing brewing water, whereby the water module (100) comprises a first heating device-a device (120), the first heating device (120) comprising a water heater (121) and a first heating element (123), the water heater (121) comprising a tank (122) with a fresh water inlet (12), the first heating element (123) being adapted to heat water to a first temperature T₁(ii) a And

-a brewing module (200) having a brewing device (220) for brewing a predetermined quantity of coffee with brewing water and a dispensing unit (230) for dispensing the brewed coffee, and a second heating device (250) arranged in a brewing water supply line (260) to heat the coffee that has been heated upstream of the brewing device (220) to the first temperature T₁Is heated to a second temperature T₂，

It is characterized in that

The second heating device (250) housed in the brewing module (200) is a thick film heater (252) designed as a continuous flow heater.

2. The coffee machine (1) according to claim 1, characterized in that housed in the water module (100) is a third heating device (130) located downstream of the first heating device (120).

3. The coffee machine (1) according to claim 2, characterized in that the third heating device (130) is a thick film heater (132) designed as a continuous flow heater.

4. The coffee machine (1) according to one of the preceding claims, characterized in that the first temperature T of the water adjustable by means of the first heating device (120)₁Between 70 ℃ and 85 ℃.

5. The coffee machine (1) according to one of the preceding claims, characterized in that the temperature T of the water that can be adjusted by means of the second heating device (250)₂Between 80 ℃ and 98 ℃.

6. Coffee machine (1) according to one of the preceding claimsCharacterised in that the second heating device (250) is arranged to heat the water to an adjustable second temperature T according to a predetermined temperature profile₂。

7. The coffee machine (1) according to one of the preceding claims 2 to 6, characterized in that the temperature T of the water adjustable by means of the third heating device (130)₃Between 70 ℃ and 98 ℃.

8. The coffee machine (1) according to one of the preceding claims 2 to 7, characterized in that the water heated by means of the third heating device (130) is fed as bypass water to the brewing device (220) and is brought together downstream of the brewing chamber (240) of the brewing device (220) with the coffee brewed in the brewing device (220) and is dispensed at the dispensing unit (230).

9. The coffee machine (1) according to one of the preceding claims 2 to 8, characterized in that the water heated by means of the third heating device (130) is fed to the dispensing unit by means of the drain line (18) and mixed with cold water for preparing tea or similar infusion drinks.

10. The coffee machine (1) according to one of the preceding claims, characterized in that the brewing device (220) has a support in which a handle with a filter can be received, in which a predetermined quantity of coffee can be filled, whereby the brewing device (220) comprises a brewing piston which is movably supported for repeatedly closing and opening the brewing chamber (240).

11. Coffee machine (1) according to one of the preceding claims, comprising:

-an operating lever which is at least partly movable by hand, whereby the brewing piston in the brewing chamber (240) is pushed into a pressing position and/or a brewing position as the operating lever moves in one direction, and

-an adjustment device having a fluid system, the adjustment device comprising at least one first cylinder/piston configuration, whereby the operating rod is in operative connection with the piston of the first cylinder/piston configuration and with the adjustment configuration, such that as the operating rod is moved in one direction, a pressure is built up in the fluid system, whereby a brewing piston arranged in a second cylinder/piston configuration in the brewing chamber (240) is pushed into a pressing position and/or a brewing position.

12. The coffee machine (1) according to one of the preceding claims, characterized in that it comprises a plurality of infusion modules (200).

13. The coffee machine (1) according to one of the preceding claims, characterized in that the water module (100) comprises individual control devices for controlling the first heating device (120) and the third heating device (130) and for controlling the devices for delivering and metering water.

14. The coffee machine (1) according to one of the preceding claims, characterized in that the brewing module (200) has individual control devices for controlling the second heating device (250) and for controlling the devices for delivering, metering and brewing water.

15. The coffee machine (1) according to one of the preceding claims, characterized in that it comprises a central control unit for controlling the first heating device (120), the second heating device (250) and the third heating device (130) and for controlling the devices for delivery, metering and brewing.

Technical Field

The present invention relates to a coffee machine for preparing hot drinks, in particular a coffee machine with a heating system for dynamic thermal management.

Background

Known coffee machines for preparing hot drinks comprise a hot water unit with a device for supplying brewing water (brewing water) and/or steam. The hot brewing water is fed on the inlet side to a brewing device or brewing unit provided in the coffee machine and on the outlet side the sufficiently brewed coffee is dispensed. For this purpose, the water is typically conveyed out of the water tank by means of a pump or similar device, and the water is heated to the desired temperature in one or more heating devices. In addition to simple flow heaters, which provide only a minimum flow of brewing water, water heaters (boilers), in which a larger amount of brewing water can be heated to a desired temperature, are also referred to as heating elements. The brewing water is thus completely heated in a more or less large brewing tank and then fed to the brewing unit or also to a plurality of brewing units. This is particularly relevant in the case of the professional use of coffee machines in cafes and bars, which are equipped for increased workload and with which several hundred to one thousand servings of coffee are prepared, which are irregularly distributed during the day.

It is known to use a plurality of water heaters in professional coffee machines in order to achieve a stable temperature constancy and in order to reduce the energy consumption caused by heating and maintaining the temperature of a large quantity of water. The second water heater can thus store a relatively small amount of water and can be assigned directly to the brewing device to heat the brewing water to the second temperature, i.e. the brewing temperature.

Heating devices designed as water heaters usually comprise a heating element designed as a heating coil in the lower region, whereby temperature stratification is formed in the water heater. Whereby cold water is supplied to the boiler from a water source by means of a pump via an inlet arranged in a lower or central region in the boiler and heated brewing water is dispensed or extracted from an upper region via a brewing water outlet port.

In addition to generating hot brewing water, it is also desirable to provide steam for preparing hot drinks, in particular coffee specialties (speciality). The steam may be used, for example, to froth milk. Combined systems are known in which the included water heater is arranged to produce steam in addition to heated brewing water. However, a convenient coffee machine provides separate devices to provide heated brewing water on the one hand and steam on the other hand.

In any case, the heated brewing water flows from the heating device to the brewing device along a path of a certain distance, so that the temperature of the brewing water fluctuates for the actual brewing process and thus also for the brewing quality to be achieved, depending on the type, point in time and frequency of the previous brewing program. The brewing quality depends to a large extent on the brewing temperature, so that the ideal brewing temperature differs depending on the coffee speciality (e.g. espresso, cappuccino), but in particular should be constant. The coffee machine itself is therefore distinguished on the one hand by a great thermal stability in order to minimize the temperature fluctuations of the brewing water, which are evident for continuous water distribution. On the other hand, there should be a minimum thermal inertia, so that a quick reaction and adaptation to the required temperature can be made, in particular after switching off and resuming operation of the coffee maker.

From WO 2017/068522 a professional coffee machine is known, which has a dispensing device for coffee and steam and hot water for preparing tea and other drinks. A water heater is provided in which the supplied cold water is heated and in which the heated water is in equilibrium with steam which can be extracted for further use. At least one heat exchanger is in thermal contact with the heated water in the boiler, so that the water is thereby heated to a first temperature and, downstream, further heated to a selectable brewing temperature by means of a further temperature-controlled heating element. Via a second heat exchanger, possibly provided in thermal contact with the water heater, water with another temperature can be provided for preparing tea.

Furthermore, a multi-stage heating device for a coffee machine is known from US 6701068, whereby a first heating device and a second heating device are arranged along the flow path of the brewing water to be heated. In particular, by means of the second heating device, temperature losses downstream of the first heating device will be compensated.

Disclosure of Invention

The object of the present invention is to provide a coffee machine for preparing hot drinks which ensures an individually adjustable temperature of the brewing water for preparing coffee specialties and for preparing tea or the like as optimum as possible. Thus, a constant temperature can be set, or a temperature profile or temperature course can also be generated, whereby the brewing water is heated in a defined manner during the brewing process. In particular, a coffee machine also for professional use will be provided, which is able to heat quickly and reliably a sufficient quantity of hot brewing water for different special uses to an adjustable optimum temperature.

These objects are achieved according to the invention by the subject matter of claim 1. Further advantageous features result from the dependent claims, the following description and the drawings.

The coffee machine for preparing a hot beverage according to the invention comprises a housing frame in which the water module and the infusion module are housed. Furthermore, a steam module for generating and distributing steam may be arranged in the housing frame. The individual modules are integrated in the housing frame of the coffee maker and can be electrically connected to one another and can be connected to one another in a fluid-conducting manner. The individual modules can be controlled by means of control devices individually assigned to them and/or by means of a central control unit. The coffee machine comprises a heating system for dynamic thermal management having a controllable heating device partly housed in the brewing module and partly housed in the water module.

A water module for providing brewing water comprises a first heating device comprising a boiler having a fresh water inlet and a first heating device for providing heating to a first temperature T₁A first heating element of the water. The water module is of modular design as such and is accommodated in a water module housing. In addition to the first heating element, further devices are included, such as a line system and pumps, valves, metering devices and sensors, for providing heated and metered brewing water which is heated to a first temperature T in a first stage₁. The first temperature T₁Preferably in the range between 70 ℃ and 85 ℃. The temperature T₁In particular slightly lower than for the preparation of a specific coffee with high qualityThe optimum temperature of the article.

According to the invention, the first heating device is designed as a water heater, whereby the water tank is provided with a filling volume adapted to the need, wherein via a pump water, preferably cold water, is supplied via a water inlet, preferably arranged in the lower region. The filling level or level of the water can be determined by means of a sensor and can be made available as a parameter to the control system. Water heaters in connection with hot beverage makers are already known and can therefore be used cost-effectively as a standard part. For example, the heating element of a water heater can be designed as one or more stages of heating coils which are arranged inside the water tank and are distinguished in particular with a high degree of efficiency. The water heater is arranged to heat a volume of water to a first temperature T₁And store this water until further use. The temperature of the water heated in the water heater can be controlled by means of one or more temperature sensors and a control device or a central control unit, whereby the latter acts in a controlled manner on the heating element.

The brewing module has a brewing device for brewing a predetermined quantity of coffee with brewing water and a dispensing unit for dispensing the brewed coffee, and has a second heating device arranged in a brewing water supply line to be heated to the first temperature T₁Is heated to a second temperature T₂. In addition to the brewing device and the dispensing unit, the brewing module may have a device in the brewing module housing for supplying brewing water at a predetermined temperature and under pressure in a metered manner into the brewing unit having a brewing chamber for receiving a predetermined quantity of coffee. In doing so, the so-called brewing pressure may vary during the brewing process (i.e. during extraction). Typically, the brewing pressure amounts to about 9 bar. In one embodiment, the brewing device comprises a support in which a handle (portafilter) with a filter can be accommodated, in which a predetermined quantity of ground coffee can be filled, whereby the brewing device comprises a brewing piston which is accommodated in a movable manner for repeatedly closing and opening the brewing chamber. Via the brewing water supply line, heated brewing water can be supplied into the brewing chamber, the second heating device being arranged in the brewing water supply line to heat the brewing water individually to the second temperature T as required₂. Preferably, the second temperature T₂Corresponding to the optimum temperature of the coffee speciality to be brewed and preferably between 80 ℃ and 98 ℃. It may also be provided that the temperature is varied during the brewing process, for example by creating a temperature profile in the brewing water by means of the second heating device, so that the brewing process is started at a lower temperature and in a gentle manner to protect the ground coffee substance, and then the temperature is raised along the temperature profile to a corresponding optimum temperature.

Furthermore, the brewing device may comprise a bypass supply line, via which a definable amount of heated water can be supplied as bypass water, guided through the quantity of ground coffee filled in the brewing chamber and, downstream of the brewing chamber, brought together with the brewed coffee coming out of this chamber. The temperature of the bypass water can likewise be adjusted individually by means of the second heating device. This bypass water is particularly relevant for the preparation of american coffee.

According to the invention, the second heating device housed in the brewing module is a thick-film heater designed as a continuous flow heater. The second heating device is arranged in such a way that, on the one hand, it transfers well the thermal energy generated with the heating element to the brewing water which has been heated in the first heating device and flows through the second heating device, and, on the other hand, it has a small mass, so that it is controllable in a fast and reliable manner and can be activated again after a stationary period, i.e. it has a steep control curve or a short reaction time. In the second heating element, which is designed as a continuous flow heater, the water to be heated is in thermal contact with the heating element along the provided flow path. The second heating device comprises a resistive heater designed as a thick film heater. For this purpose, the heating element is mounted on a substrate, preferably a ceramic substrate, having a certain layer thickness, so that this element has a limited heat capacity. Such thick film heaters are distinguished by a relatively minimal delay in control performance so that consistent heat transfer to the flowing water is achieved. Alternatively, the second heating device may be designed as a PTC heating resistor. Another alternative is to design the second heating device as a water heater with a certain capacity.

By the arrangement of the second heating device in the brewing module, a short connection path between this device and the brewing chamber of the brewing module can be achieved, such that temperature losses along the flow path of the brewing water are minimized.

Second temperature T₂(the water taken from the first heating device is heated separately in the second heating device to a second temperature T₂) The compliance is dependent on the optimum temperature of the coffee speciality to be produced and is generally between 80 ℃ and 98 ℃, preferably between 85 ℃ and 95 ℃. It is thus considered that, on the one hand, when the brewing water temperature is too high, the bitter substances are increasingly released from the coffee to be extracted, and, on the other hand, when the brewing water temperature is too low, the flavouring substances are not sufficiently extracted, so that the taste is unsatisfactory.

In one embodiment, provision is made for a third heating device downstream of the first heating device to be additionally accommodated in the water module in order to heat to the first temperature T₁The water used as bypass water and/or for preparing tea is led to a further third heating device, which is assigned to the water module.

Thus, the water stored in the boiler and heated in the first stage can be individually further heated, and not only made available to the brewing module as brewing water via the brewing water supply line, but the water can also be led out of the boiler via a correspondingly provided hot water line and supplied to a bypass supply line and/or to another application for preparing tea or other brewed drinks. The third heating device is assigned to the water module and is accommodated in a water module housing delimiting the water module. According to the invention, the third heating device is designed as a continuous flowA thick film heater for a moving heater, the continuous flow heater having a defined flow path for water to be heated. Further devices may be arranged in the incorporated pipeline system, which devices are necessary for the controlled delivery and metering of water. Preferably, the devices are arranged downstream of the first heating device and upstream of the third heating device. In this way, the temperature T of the heated water that can be adjusted by means of the third heating device₃Preferably between 70 ℃ and 98 ℃. The temperature controlled water may be supplied as bypass water via a line system to the brewing module or modules of the coffee machine, to separate supply lines of the brewing module or modules. Thus, the plurality of brewing modules may also be designed differently. Furthermore, the water may be directed to a dispensing unit for heated water for preparing tea or other infusion drinks, whereby it may be mixed with cold water in a suitable manner. Thus, for example, for the preparation of green tea, an optimum temperature of about 70 ℃ may be provided, and for black tea or herbal tea, an optimum temperature of about 95 ℃ may be provided.

In one embodiment of the coffee maker, it is foreseen that the water module has individual control devices; by means of this individual control device, control of the first and third heating devices and the device for conveying and metering water is possible. Furthermore, the brewing module may also have individual control devices for controlling the second heating device and for controlling the devices for delivering, metering and brewing. Furthermore, a central control unit for controlling the first, second and/or third heating devices and the devices for delivery, metering and brewing is foreseen.

In addition to a precisely adjusted temperature or temperature profile, it is important for an optimal brewing process to have a precise metering of the amount of brewing water, which can be adjusted to the respective heating element. For this purpose, a plurality of restrictors can be arranged in the lines conducting the infusion water and in the heating system, these devices being adjustable with respect to the diameter variation or respectively, depending on the coffee speciality to be prepared. Thus, it has been shown to be particularly suitable for preparing espresso coffee with a compression diameter of about 0.4mm to 0.6mm, for preparing crema and/or american coffee with a compression diameter of about 0.7mm to 0.9mm, and for use as bypass water with a compression diameter of about 0.5mm to 0.8 mm.

In one embodiment, the coffee machine according to the invention can be designed in a comparable manner to a handle machine (portafiltermachine), whereby a support is provided in the brewing device, in which support a handle with a filter can be received, in which handle a predetermined quantity of coffee can be filled. The brewing device comprises a brewing piston movably supported for repeatedly closing and opening the brewing chamber. It is thus also foreseen to provide an operating lever which is at least partly moved by hand, whereby by moving the operating lever in one direction the brewing piston in the brewing chamber is pushed into the pressing position and/or the brewing position. Furthermore, an adjustment device with a fluid system is provided, which adjustment device comprises at least one first cylinder/piston arrangement, whereby the operating rod is in operative connection with the piston of the first cylinder/piston arrangement and with the adjustment arrangement, such that as the operating rod is moved in one direction, a pressure is built up in the fluid system, whereby a brewing piston arranged in a second cylinder/piston arrangement in the brewing chamber is pushed into a pressing position and/or a brewing position.

Drawings

An embodiment example of the present invention will be described in more detail below with reference to the accompanying drawings.

Figure 1 schematically shows a coffee machine for preparing a hot beverage with a heating system for dynamic thermal management according to the present invention;

figure 2 schematically shows a water module of a coffee machine according to the invention; and

figure 3 schematically shows a brewing module of a coffee machine according to the invention.

Detailed Description

Fig. 1 schematically shows a coffee maker 1 according to the invention, comprising a water module 100, at least one brewing module 200, and in the embodiment variant shown, a steam module 300, which modules are integrated into a housing frame 2. These modules are electrically connected to each other and in a fluid conducting manner to each other, as is at least partially shown in fig. 1. The water module 100 comprises a water module housing 110, the brewing module 200 comprises a brewing module housing 210, and the steam module 300 comprises a steam module housing 310, in each case (not shown), in which corresponding devices for conveying, metering and/or brewing and/or control are accommodated.

Further details of the coffee maker 1, in particular those relating to the apparatus for storing and/or grinding coffee or ground coffee, the conveying device of coffee or ground coffee and the central control unit, the actuating means and the control means, which are necessary for preparing coffee, are not shown. Also, the flushing system of the coffee maker 1, which is arranged to flush and/or evacuate the fluid conducting connection, is not shown.

In fig. 1, it is shown that preferably cold water is fed to the water module 100 from a water source or water supply system via a preferably controllable valve 16 via a fresh water feed line 12 by means of a water pump 14. The amount of supplied water can be recorded by means of a flow meter (not shown) and the captured values can be transmitted to the control unit (not shown) and/or a central control unit of the water module. A drain line 18 is shown via which drain line 18 the water heated in the water module can be supplied in a metered manner to a dispensing unit (not shown), possibly in combination with a predeterminable amount of cold water supplied via line 11, for preparing tea or other infusion drinks.

Further, connectable to the water module 100 is a line system for connection to the brewing module 200. The line system comprises a first line 20, in the course of which first line 20, for example, a restriction 22 and a non-return valve 24 are arranged, and by means of which the brewing module 200 can be loaded with heated brewing water as bypass water, which is used for preparing american coffee. The line system further comprises a second line 26 for fluid conductive connection of the water module 100 to the brewing module 200, in the second line 26, in the embodiment shown, a controllable valve 28 is arranged, and via the controllable valve 28 the brewing module 200 can be loaded with heated brewing water. The at least one brewing module 200 is configured to brew a predetermined quantity of coffee and dispense freshly brewed coffee at the at least one dispensing unit 230. For example, to prepare a coffee speciality, the brewing chamber 240 arranged in the brewing module 200 is loaded with metered, heated and pressurized brewing water via line 26.

A steam module 300, which is assigned to the coffee machine 1 and arranged as a separate unit within the housing frame 2, can be loaded with water, preferably fresh water, and is arranged to deliver steam to a steam outlet 330 controlled by a valve 320, for example for preparing milk froth.

In fig. 2 a water module 100 of the coffee maker 1 according to the invention is shown. The water module 100 is of modular construction; preferably, the included devices and elements are arranged in the water module housing 110 and are electrically and fluid-conductively connected to each other.

In this embodiment example, a first heating device 120 designed as a water heater 121 is included. The boiler 121 has a water tank 122 with a filling volume adapted to the number of servings of coffee to be prepared with the coffee maker 1. Preferably, a fresh water inlet 12 is arranged in the lower region of the water heater 121, via which fresh water inlet 12 fresh water can be supplied in a metered manner by means of a water pump 14 and a valve 16. Furthermore, a first heating element 123 of the first heating device 120 is schematically shown, which is designed, for example, as a single-stage or multi-stage heating coil that heats the water filled in the water tank 122 to a first temperature T₁. Temperature T₁It may preferably be slightly lower than the temperature required for optimal brewing of the coffee drink, which is typically between 85 ℃ and 95 ℃. A temperature sensor (not shown) can be arranged on the water heater 120, which records the heating of the water stored in the water tank 122 and transmits the temperature value to the control device and/or the central control unit of the water module, which controls the first heating device 120 and the other devices of the water module, respectively. Furthermore, a sensor for registering the fill level is provided in the water tank 122A device (not shown). As a result, advantageously, with the heating of the brewing water in the first heating device 120, the scale contained in the fresh water settles there and therefore not in the line system and not in the devices downstream of the first heating device 120, which would lead to clogging of these elements.

Heated to a first temperature T in a first heating device 120₁The water of (2) is now available for further use. Thus, via the second line 26 arranged in the upper region of the water heater 121, heating is effected to a temperature T₁May be supplied to the brewing module 200 and used there directly as brewing water. This will be explained in more detail with reference to fig. 3. In the case of multiple brewing modules 200, the line system is correspondingly configured for fluidly conductively connecting the water module 100 to the multiple brewing modules 200.

A discharge line 18 for the fluid conductive connection delivering the water for preparing tea and/or a first line 20 for the fluid conductive connection with the brewing module 200 are likewise arranged in the upper region of the water heater 121, whereby, according to the invention, the heated water taken out of the water heater 121 is fed to a third heating device 130 downstream of the water heater 121. The third heating device 130 is designed as a continuous flow heater, preferably as a thick film heater 132. For this purpose, the third heating device 130 comprises a resistive heater designed as a ceramic thick film heater 132, whereby a heating element is mounted on the ceramic substrate and in thermal contact therewith, a flow path for the water to be heated being available. The third heating device 130 heats the water to a temperature T₃Temperature T₃Adjusted to an optimal temperature for further use, i.e. as bypass water or for preparing tea or other infusion drinks. What can be arranged in the fluid conducting connection between the first heating device 120 and the third heating device 130 is a restriction 133, which restriction 133 controls the flow of flowing water, whereby corresponding information can be transmitted to the control device and/or the central control unit. Thus, a control may be provided to activate or deactivate the third heating device 130 depending on the flow rate and temperature of the supplied water.

Accurate metering of the amount of water is necessary, especially if bypass water is provided. This metering should be adjusted according to the extraction cycle for preparing the coffee, so that the brewed coffee together with the bypass water is dispensed into a ready cup for a duration of time. This is achieved, for example, by means of a limiter 133, which can be adjustable or the diameter of which is selected accordingly. The diameter should not be so large that the discharge of the bypass water does not look like a surge. However, in case the diameter is too small, the problem arises that the bypass water is delivered over a longer time span, possibly exceeding the extraction cycle of the coffee. The flow path of the bypass water is taken by means of a first line 20 in the course of which, for example, a restriction 22 and a check valve 24 are arranged.

The brewing module 200 of the coffee maker 1 according to the invention is shown in fig. 3. The brewing module 200 is also modularly constructed, whereby this module comprises at least one brewing device 220 arranged in the brewing module housing 210, said at least one brewing device 220 being for brewing a predetermined amount of coffee with pressurized and metered brewing water, and a dispensing unit 230 for dispensing freshly brewed coffee. In particular, the brewing device 220 has a brewing chamber 240 in the brewing unit, into which a predetermined quantity of coffee can be received and into which a metered amount of water can be introduced via a brewing water supply line 260.

Furthermore, the brewing module 200 comprises a device for heating the brewing water under pressure to a predetermined temperature. The brewing water eventually introduced into the brewing chamber 240 is heated to the first temperature T by means of the first heating device 120₁And is fed to the brewing chamber 240 via the fluid conducting line or via the second line 26 and the brewing water supply line 260, thereby further heating it by means of the second heating device 250.

In the illustrated embodiment, it is foreseen that parallel flow paths 262, 264 are provided upstream of the brewing chamber 240 and downstream of the second heating device 250. A valve 265, 266 and a restrictor 267, 268 are arranged in the parallel flow paths 262, 264, respectively. By means of the restrictions 267, 268, metered amounts of water can be selectively supplied for preparing espresso and crema or american coffee, whereby for preparing espresso a smaller amount of brewing water is required than is required for preparing crema/american coffee. Thus, the jet diameters of the restrictors 267, 268 may be different relative to their diameters.

Assigned to the brewing module 200 and accommodated in the brewing module housing 210 is a second heating device 250, which second heating device 250 is designed as a continuous flow heater as a thick film heater 252. The second heating device 250 is arranged to heat brewing water conducted along a flow path arranged therein to an adjustable temperature T₂. The heating element comprised in the second heating device 250 is designed as a resistive heater or as a thick film heater 252 and is controllable by the control device and/or the central control unit of the brewing module 200 according to the input requirements. For this purpose, at least one temperature sensor (not shown) may be provided in relation to the second heating device 250, which at least one sensor preferably detects temperature measurement values on the outlet side and/or the inlet side and transmits these values to the control device and/or the central control unit of the brewing module. Thus, the control system can control the current applied to the resistive heater based on the temperature measurement. The configuration of the second heating device 250 in the brewing module 200 permits a short flow path of the heated brewing water into the brewing chamber 240 downstream of the second heating device 250, so that the heated brewing water (temperature controlled to an optimal temperature) can be introduced into the brewing chamber 240 without significant temperature fluctuations. The brewing water heated in this manner can be used inside the brewing device 220 to brew a coffee drink by guiding or pressing the brewing water through the ground coffee or coffee powder received in the brewing chamber 240 and to dispense it at the dispensing unit 230 as a freshly brewed coffee speciality.