Device for discharging and heating milk

Abstract

A device for discharging milk and/or milk froth, including a pump to convey milk from a container, a flow-heater, and an output for discharging milk, embodied cooperating with each other such that milk conveyed via the pump and heated via the flow-heater can be discharged from the output. At least one steam generator is provided cooperating with the flow-heater such that downstream in reference to the flow-heater and upstream in reference to the output, steam can be fed to the milk for an additional heating step. An air valve to create milk froth is provided, and the air valve is openable to introduce air upstream in reference to the flow-heater.

Claims

1. A device for discharging milk, comprising a pump (P1) to convey milk from a container (31), a flow-heater (32), and an output (33) to selectively discharge hot milk or milk foam, which cooperate with each other such that the milk conveyed via the pump (P1) and heated via the flow-heater is discharged from the output (33), and at least one steam generator (34) connected downstream in reference to the flow-heater and upstream in reference to the output to feed steam to the milk for an additional heating process to discharge hot milk, and an air valve to create milk froth, the air valve is openable to introduce environmental air upstream in reference to the pump and the flow-heater upon the at least one steam generator being deactivated for preparation and discharge of the milk froth.

2. A device according to claim 1, further comprising a control unit, which controls at least one of the pump (P1) or the flow-heater (32) such that the hot milk at the output of the flow-heater has a temperature ranging from 50 C. to 85 C.

3. A device according to claim 1, wherein downstream in reference to a steam supply site at which steam is added to the milk and upstream in reference to the output, a calming line is provided, through which milk heated by steam during operation flows, the calming line has a length of at least 5 cm.

4. A device according to claim 1, further comprising a refrigerator in which a milk container can be arranged and at least the pump (P1) also being arranged therein.

5. A device according to claim 1, wherein the pump (P1) comprises a controlled throttle valve, which is arranged at a pressure side of the pump (P1) and the controlled throttle valve has a flow-through cross-section that is pre-determined by control signals.

6. A device according to claim 1, wherein a bypass is provided between the pump (P1) and the output (33) that provides for bypassing of the flow-heater.

7. A device according to claim 1, wherein the flow-heater includes two parallel lines, with a first line adapted to heat the milk and a second line adapted to heat another liquid.

8. An automatic coffee maker comprising at least one brewing unit and a device for heating milk according to claim 1, with the brewing unit being adapted for creating coffee and at least one output (33) to discharge coffee, which is identical or adjacent to the output (33) to discharge the heated milk.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional preferred features and embodiments of the invention and the method according to the invention are explained in the following using exemplary embodiments and the figures. Shown are:

(2) FIG. 1 is a view of a first exemplary embodiment of the device according to the invention embodied as an automatic coffee maker, and

(3) FIG. 2 is a view of a second exemplary embodiment of the device according to the invention embodied as an automatic coffee maker and a flow-heater with two parallel milk lines.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) The automatic coffee maker shown in FIG. 1 comprises a device for discharging milk.

(5) It comprises a pump P1, which at the suction side is connected via a suction line to a container 31 for milk. At the pressure side the pump P1 is connected via a two-way valve Y9 to a flow-heater 32. The output of the flow-heater 32 is connected via a drainage valve Y10, embodied as a two-way valve, to an output 33. The output comprises two openings, spaced apart from each other, so that optionally the discharge is possible into a cup and/or two cups placed side-by-side.

(6) Thus, milk can be conveyed via the pump P1 from the container 31, heated via the flow-heater 32, and discharged from the output 33, for example into a cup.

(7) It is essential that the device further comprises a steam generator 34 for generating water vapor.

(8) This is connected via a steam line 35 to a milk line between the drainage valve Y10 and the output 33, with the steam line mouthing in the milk line at a steam introduction point 35a.

(9) This way it is therefore possible that via the pump P1 milk conveyed from the container 31 is heated in a first heating stage via a flow-heater 32 and subsequently, via feeding steam from the steam generator 34 to the steam introduction point 35a, additionally heated in a second heating stage by said steam.

(10) All components of the automatic coffee maker according to FIG. 1 are connected to a control unit, not shown. If the output of hot milk is desired, the control unit controls the components such that the milk conveyed via the pump P1 exhibits a temperature of approximately 70 C. at the output of the flow-heater 32 and is heated to a temperature of approximately 90 C. by supplying steam at the steam introduction point 35a. Here the flow rate amounts to approximately 0.8 l/min.

(11) In order to allow precisely regulating the flow rate of the pump P1 further a throttle Y22 is provided at the pressure side of the pump between the pump P1 and the milk valve Y9. It is within the scope of the invention to control the rotations of the pump P1 in order to yield a predetermined flow rate.

(12) It is also possible for the pump P1 to be operated at full capacity and a precise control of the conveyed amount occurring by throttling the cross-section at the pressure side of the pump to a predetermined value via the throttle Y22.

(13) If at the beginning of the milk conveyance rinse water is still present in the milk lines it is first guided via the drainage valve Y10 into a drain and subsequently the drainage valve Y10 is switched so that the heated milk is now discharged via the output 33.

(14) The fluid line has a length of 20 cm between the steam introduction point 35a and the output 33. This serves to calm the steam-milk mixture.

(15) The temperature of the flow-heater 32 is monitored via a temperature sensor B3 and can thus be controlled via the control unit.

(16) In order to discharge cold milk the pump P1 is operated with maximum capacity and the throttle Y22 is opened to its maximum cross-section. The milk valve Y9 is controlled such that the milk is directly fed to the output 33 bypassing the flow-heater 32.

(17) The device according to the invention is additionally suitable to discharge cold or warm milk froth.

(18) For this purpose, the device comprises an intermittent air valve Y21, which on the one side is connected to the environment and on the other side to the milk line between the container 31 and the pump P1. The connection is embodied such that in case of an open air valve Y21 and during the conveyance of milk via the pump P1, due to the Venturi effect, air is suctioned in and the conveyed milk is mixed in.

(19) The air valve is here operated intermittent via the control unit, i.e. by a fast clocking between open and closed state the amount of air added is controlled.

(20) This way, high-quality milk froth is created and furthermore it is possible to control the foam consistency in any arbitrary fashion.

(21) The use of an intermittent air valve for creating milk froth is known per se and described in DE 10 2009 041 809 A1 for example.

(22) In order to create cold milk froth the milk pump P1 is switched on at full capacity, the throttle Y22 is set to maximum cross-section, and the air valve Y21 is opened intermittently with predetermined opened and closed cycles.

(23) Any still present rinse water is here guided at the beginning into the drain via the drainage valve Y10 and subsequently the cold milk froth is fed by an appropriate control of the milk valve Y9 to the output 33, bypassing the flow-heater 32.

(24) In general the same process is used to create warm milk froth, however the milk valve Y9 is controlled such that the air-milk mixture is guided via the flow-heater 32 to output 33 and thus, by heating via the flow-heater 32, warm milk froth is discharged. Here, it is particularly advantageous to set the throttle Y22 to a lower than maximum cross-section because this way the consistency of the warm milk froth is improved.

(25) In order to rinse the milk lines, the device comprises a rinse line 36 which mouths in the milk supply line between the intermittent air valve Y21 and the mouthing point of the air supply line in the milk suction line. Via a main water valve Y1, a main water pump M1, and a cleaning valve Y5, also embodied as a two-way valve, the rinse line 36 can optionally be supplied with water or steam.

(26) It is advantageous first to rinse with cold or warm water. For the rinsing process initially the milk suction line is closed via a valve Y20, so that no rinsing medium can reach via the suction line into the container 31. Subsequently, for example water is introduced via the main water pump M1 and the rinsing line 36 into the milk line, so that water passes the pump P1, the throttle Y22, the flow-heater 32, and the drainage valve Y10 and subsequently by an appropriate control of the drainage valve Y10 is released into the drain. Subsequently the valve Y5 is controlled such that the steam generated by the steam generator 34 is inserted into the rinsing line 36 and additional cleaning occurs using steam.

(27) The other components of the automatic coffee maker according to FIG. 1 are embodied in a manner known per se and operated in a known fashion.

(28) The steam generator 34 comprises a heater H2, a level probe B4, and a temperature sensor B2. Water can be fed via a valve to the steam generator using the main water pump M1. These components are controlled by the control unit such that when necessary at least in the upper part of the steam generator sufficient water steam is provided. For safety reasons a pressure valve UV is provided.

(29) As described above, steam from the steam generator 34 can be guided to the milk line for heating the milk in a second heating stage. Additionally, the discharge of steam via a valve Y8 to a steam injection lance of the automatic coffee maker is possible.

(30) Furthermore, hot water can be discharged from the steam generator via a valve Y7 to an output, for example when tea is requested.

(31) In order to create coffee the automatic coffee maker comprises a water boiler with a heater H1 and a temperature sensor B1 as well as, for safety reasons, also a pressure valve UV. The water boiler is also connected via the main water valve Y1 and the main water pump M1 to the main water line, with the heater H1 and the other components being controlled such that hot water for creating coffee is provided with the desired temperature. For the control a flow meter B7 is provided particularly at the cold water supply line to the boiler. The hot water from the boiler is fed via a valve Y4 to a brewing chamber BK. This brewing chamber is embodied in a manner known per se, and particularly embodied with a powder supply chamber and a grinder in a manner known per se for automatic coffee makers. Using this hot water coffee is created, which is also discharged adjacent to the output 33 to a coffee output 37, which also comprises two output openings distanced from each other.

(32) FIG. 2 shows a second exemplary embodiment also formed as an automatic coffee maker, which in its general design is identical to the first exemplary embodiment. Identical reference elements mark identical elements or elements with identical functions.

(33) In order to avoid repetitions, in the following only the differences shall be discussed.

(34) The automatic coffee maker according to FIG. 2 has a flow-heater 32 with two parallel lines. Via a valve Y20 a pump P1 can optionally be connected to a first or a second of the parallel lines in a fluid-conducting fashion. Furthermore, the automatic coffee maker comprises a cooling unit to accept a first milk container 31a and a second milk container 31b. Optionally one of the two containers 31a or 31b can be connected via two suction lines and a valve Y20 to a suction line of the pump P1.

(35) The container 31a comprises cow's milk, the container 31b however lactose-free milk. Depending on the discharge desired, here milk or lactose-free milk can be heated in the flow-heater, perhaps additionally heated by the supply of steam in a second step, and discharged at an output 33. It is essential that in the flow-heater separate parallel lines are provided for cow's milk and lactose-free milk so that particularly for lactose-intolerant users it is ensured that no residue of cow's milk can reach the drink prepared with lactose-free milk via the flow heater.

(36) In a preferred embodiment, deviating from FIG. 2, for each milk container one pump, one suction line, and one supply line for a respective line of the flow-heater are provided such that even in the flow path upstream in reference to the flow-heater the flow paths for cow's milk and lactose-free milk are completely separate.