WO2022106367A1

WO2022106367A1 - Hot-beverage machine, in particular coffee machine, and method for operating such a machine

Info

Publication number: WO2022106367A1
Application number: PCT/EP2021/081731
Authority: WO
Inventors: Bernd Buchholz; Marcus Meyer; Nico Stellhorn
Original assignee: Melitta Professional Coffee Solutions GmbH & Co. KG
Priority date: 2020-11-18
Filing date: 2021-11-15
Publication date: 2022-05-27
Also published as: JP2023549318A; DE102020130422A1

Abstract

A coffee machine which has at least the following: a) a steam and hot-water supply (1), having a steam generator (10), which can be fed with water by a steam-generator feedline (12), and a hot-water generator (20) which can be fed with water; b) a brewing unit (40), in which the hot beverage which is to be prepared can be prepared with water from the hot-water generator (20); c) and a beverage-dispensing means (70), from which the prepared beverage can be discharged into a receptacle, is distinguished in that d) the water which is to be conducted to the hot-water generator (20) can be conducted in the first instance through the steam generator (10), or along the same, before it can be conducted into the hot-water generator (20), wherein a heat exchanger (17) is formed in the region of the steam generator (10).

Description

Hot drinks machine, in particular fully automatic coffee machine, and method for operating such a machine

The present invention relates to a hot drinks machine, in particular a fully automatic coffee machine, according to claim 1 and a method for operating a fully automatic coffee machine according to claim 8.

Fully automatic coffee machines, in which coffee beans are freshly ground and the coffee powder produced in this way is fed to a brewing chamber in which a coffee drink is prepared by hot water from a hot water generator being pressed through the compacted ground coffee, are known from the prior art in a wide variety of designs and variants.

In countries with a lower voltage in the low-voltage network than 230 V (e.g. 1 10 V), only a reduced power is provided for the operation of a fully automatic coffee machine designed for 230 V mains voltage. Nevertheless, the performance of the machine should be reduced as little as possible for the first consecutive products, i.e. several coffee products should be able to be dispensed one after the other without interruption in the shortest possible time. At the same time, the quality of the product - primarily characterized by a defined preparation temperature - must remain constant.

Due to the lower mains voltage and the associated lower electrical power that can be supplied to the coffee machine, permanent heating during product preparation may not be sufficient, although the heating itself can be designed for the low mains voltage in order to set the release temperature for the next coffee machine to be dispensed drink to reach again. This can result in an undesirable waiting time until the next product preparation.

This problem is intended to be reduced by the invention.

This object is solved by the subject matter of claim 1.

Accordingly, a fully automatic coffee machine is created which has at least the following:

- A steam and hot water supply, with a steam generator that can be fed with water through a steam generator feed line and with a hot water generator that can be fed with water; - A brewing unit in which the hot drink to be prepared can be prepared with water from the hot water generator;

- As well as a beverage outlet from which the prepared hot beverage can be dispensed into a vessel, wherein

- The water, which is to be fed to the hot water generator, can first be guided through or along the steam generator before it can be guided into the hot water generator, a heat exchanger being formed in the region of the steam generator.

In this way, it is advantageously possible that even with a relatively low heat output of the hot water generator, more coffee beverages can be prepared at a desirable speed without early post-heating phases by heating the hot water generator—that is, generally without a waiting time.

In a preferred embodiment of the invention, it is provided that a supply line to the hot water generator has a changeover valve and a branch routed through the steam generator or along the steam generator and a branch routed directly into the hot water generator. When preparing mixed coffee-milk beverages, the switching valve offers the option of directing the water to the hot-water generator and heating it in the hot-water generator in order to prevent energy from being drained from the steam generator. Necessary post-heating phases of the steam generator before the preparation of coffee-milk-mix beverages, which would otherwise be necessary, e.g. to produce milk froth, are thus reduced or at best avoided. In such a case, the heating of the hot water generator can be put into operation parallel to the operation of the steam generator for preparing milk froth, so that advantageously performance-related waiting times can be compensated for by such a parallel operation.

In a further preferred embodiment of the invention, it is provided that in a first switching position of the switching valve, the water to be heated flows via the branch of the supply line that is routed through the steam generator or along the steam generator, in order to then flow preheated into the hot water generator, while the water flows directly into the hot water generator guided branch of the supply line is blocked. In this way, it is advantageously possible that even with a relatively low heat output of the hot water generator, more coffee drinks can be prepared at a desirable speed—that is, generally without a waiting time—without early reheating phases by heating the hot water generator. In a further preferred embodiment of the invention, it is provided that in a second switching position of the switchover valve, the water to be heated flows via the branch of the supply line that is routed directly into the hot water generator into the hot water generator in order to be heated there by the heater of the hot water generator, while the the steam generator or the branch of the supply line running along the steam generator is blocked. As a result, parallel operation of the steam generator and hot water generator when preparing coffee-milk mixed drinks is implemented in a structurally simple and therefore advantageous manner.

Furthermore, in a further advantageous embodiment of the invention, it is provided that the preheating capacity of the heat exchanger is increased by further coiled tubing, which are formed from the branch of the supply line in the area of the steam generator that is routed through the steam generator or along the steam generator, so that the heat exchanger can be used as a Coiled tube heat exchanger is working. As a result, an increase in performance of the heat exchanger is achieved in a structurally simple and space-saving manner.

The object is also achieved by the method according to claim 8.

Further advantageous embodiments of the invention can be found in the dependent claims.

The invention is described in more detail below using an exemplary embodiment with reference to the figures. The invention is not limited to this exemplary embodiment, but can also be implemented in other ways or equivalently within the scope of the claims. Show it:

FIG. 1: a schematic representation of the water and steam supply of a fully automatic coffee machine according to the invention;

Figure 2: a schematic representation of the water and steam supply

Variant of a coffee machine according to the invention;

FIG. 3: a schematic representation of a hydraulic system of a fully automatic coffee machine according to the invention.

FIG. 1 shows a schematic representation of a steam and hot water supply 1 for a hot drinks machine, the drinks machine being designed here in particular as a fully automatic coffee machine, more precisely as a fully automatic coffee machine. The hot drinks machine can also be designed as an automatic tea-making machine, for example. The steam and hot water supply 1 of the fully automatic coffee machine can be fed with water through a drinking water network. For this purpose, the fully automatic coffee machine is usually permanently connected to a tapping point 2 provided for this purpose. After the tap 2, a pump 3 and optionally a water meter 4, which can be designed as an impeller meter, optionally also a non-return valve 5 and again optionally a pressure gauge 6 can be connected downstream.

The steam and hot water supply 1 of the fully automatic coffee machine also has a steam generator 10 - also referred to as a steam boiler in technical jargon. The steam generator 10 here has a container 11 into which water can flow--here from the drinking water network--via a steam generator supply line 12 and can be heated by a heater 13, preferably electrically.

The steam generator 10 is intended to generate steam from the inflowing water through the operation of the heater 13 , which steam collects above the water level and can be discharged from the steam generator 10 through a steam line 14 . In order to ensure that there is always sufficient water in the steam generator 10 , the steam generator 10 can have a level sensor 15 .

The steam generated in this way can be used, for example, to froth milk, in order to use the milk foam generated by the steam and air to prepare mixed coffee and milk drinks, such as milk coffee or latte macchiato.

The steam and hot water supply 1 of the fully automatic coffee machine also has a hot water generator 20 - also referred to as a water boiler in technical jargon.

The hot water generator 20 has a container 21 in which water can be heated by a heater 22, preferably electrically. The hot water generator 20 is intended to generate hot water at a temperature of over 60° C. from the inflowing water by operating the heater 22, as is usually used for the preparation of coffee beverages. The hot water generated in this way can be discharged from the hot water generator 20 through a hot water line 23 . In order to ensure that the pressure in the hot water generator 20 is not too high, the hot water generator 20 can have a pressure sensor 24 .

In order to compensate for the resulting lower output of the heater 22 of the hot water generator 20 in the case of a power supply with a low mains voltage (e.g. 1 10 V), provision is made for the water to first be pumped through the steam generator 10 or flows along the steam generator 10 guided branch 16a of a supply line 16 before it flows preheated by the steam in the steam generator 10 to the hot water generator 20 .

This makes it advantageously possible that, despite the lower output of the heater 22 of the hot water generator 20, coffee drinks can be prepared by the heater 22 of the hot water generator 20 at a desirable speed—ie without waiting time—without early reheating phases.

In this respect, the supply line 16 and the steam generator 10 advantageously act like a heat exchanger 17. The preheating capacity of this heat exchanger 17 can be increased by additional coiled tubing, which is formed from the branch 16a of the supply line 16 that is routed through the steam generator 10 or along the steam generator 10 in the region of the steam generator 10 , be increased as required, so that the heat exchanger 17 then works like a coiled tube heat exchanger.

In this respect, the water that is to be fed to the hot water generator 20 can first be routed through the steam generator 10 or along it before it can be routed into the hot water generator, with a heat exchanger 17 being formed in the region of the steam generator 10 .

According to an alternative embodiment variant of the invention, which is shown in FIG. In addition, the supply line 16 has the branch 16a running through the steam generator 10 or along the steam generator 10 and a branch 16b running directly into the hot water generator 20—ie not through the steam generator 10 or along the steam generator 10. The switching valve 30 can be designed as a 3/2-way valve and is shown here switched to a second switching position. As shown in FIG. 2, the changeover valve 30 is preferably designed as a solenoid valve with spring reset, but it can also be designed differently.

In a first switching position of the changeover valve 30, the water to be heated flows via the branch 16a of the supply line 16, which is routed through the steam generator 10 or along the steam generator 10, in order to then flow preheated into the hot-water generator 20, while the branch 16b, which is routed directly into the hot-water generator 20, Lead 16 is blocked. As a result, in the first switching position of the switchover valve 30, the water can flow into the hot water generator 20 only via the steam generator 10—that is, preheated.

In the second switching position of the changeover valve 30 shown here, the water to be heated flows via the branch 16b of the supply line 16, which is routed directly into the hot water generator 20, into the hot water generator 20, in order to be heated there by the heater 22 of the hot water generator 20, while the steam generator 10 or on the steam generator 10 along guided branch 16 of the supply line 16 is blocked. This switch position is set when a coffee-milk mixed drink is to be prepared.

During the preparation of mixed coffee-milk beverages, the switchover valve 30 offers the option of directing the water to the hot-water generator 20 and heating it in the hot-water generator 20 in order to prevent an outflow of energy from the steam generator 10 . Necessary post-heating phases of the steam generator 10 before the preparation of coffee-milk mixed beverages, which would otherwise be required, for example, to produce milk froth, are thus reduced or at best avoided. In such a case, the heater 22 of the hot water generator 20 can be put into operation parallel to the operation of the steam generator 10 for preparing milk froth, so that performance-related waiting times can be compensated for by such a parallel operation.

FIG. 3 shows a fully automatic coffee machine according to the invention. In addition to the steam and hot water supply 1 described above, the fully automatic coffee machine has a brewing unit 40 in which the hot drink to be prepared-here preferably coffee-is brewed. Brewing units 40 of fully automatic coffee machines are known from the prior art, so that a detailed description of the brewing unit 40 is omitted at this point. The hot water required for the brewing process is supplied to the brewing unit 40 via the hot water line 23 . A brewing valve 50 is inserted in the hot water line 23 between the hot water generator 20 and the brewing unit 40 .

The brewing unit 40 is assigned at least one coffee grinder, here two coffee grinders 61, 62, which supply the brewing unit 40 with coffee powder. The respective coffee grinder 61, 62 can be operatively connected to a storage container for coffee beans. Due to the two coffee grinders 61, 62 and their associated storage containers, coffee beans of different types and/or roasts can be used to prepare the coffee beverage or coffee-milk mixed beverage. The brewing valve 50 controls the flow of hot water to the brewing unit 40. The brewing valve 50 is designed here by way of example as a 2/2-way valve and is shown here switched to a second switching position. As shown in FIG. 3, the brewing valve 50 is preferably designed as a solenoid valve with spring return.

In a first switching position of the brewing valve 50 hot water can flow through the hot water line 23 from the hot water generator 20 into the brewing unit 40 . In the second switching position of the brewing valve 50 switched here, the hot water line 23 is shut off so that no hot water can flow into the brewing unit 40 .

The coffee beverage brewed in the brewing unit 40 flows through a beverage line 41 into a first, central beverage outlet 70 and is dispensed in the first, central beverage outlet 70 into a drinking vessel placed under the optionally vertically displaceable first, central beverage outlet 70 . A diverting valve 80 is used in the beverage line 41 for this purpose

The diverter valve 80 controls the beverage flow to the first, central beverage outlet 70 or to the drain 71, this direction of flow is preferably used in the cleaning cycles of the machine. The diverting valve 80 is designed here as a 3/2-way valve and is shown here engaged in a second switching position. As shown in FIG. 3, the diverting valve 80 is preferably designed as a solenoid valve with spring return.

In a first switching position of the deflection valve 80 , a brewed coffee beverage can flow through the beverage line 41 from the brewing unit 40 into the first, central beverage outlet 70 . In a second switching position of the diverting valve 80 which is connected here, the cleaning liquid can flow into a drain 71 in the cleaning cycle. A check valve 72 can be inserted in the line to the drain 71 .

The fully automatic coffee machine also has a milk system 90 . The milk system 90 usually includes a device for milk foaming, in which milk foam is produced here with the aid of steam from milk and air. The milk can be accommodated in a milk cooler 91, packaged in a conventional milk packaging 92, such as a beverage carton--for reasons of hygiene. In order to conduct the milk from the milk packaging 92 into the milk system 90 , the milk system 90 is connected to the milk packaging 92 with a first milk line 93 . The first milk line 93 can be designed as a hose. The milk processed in the milk system 90 flows through a second milk line 94 into the first, central beverage outlet 70 and is in the first, central beverage outlet 70 -in under the optional vertically displaceable first, central beverage dispenser 70 parked drinking vessel issued.

The fully automatic coffee machine can have an auxiliary system 100 . The auxiliary system 100 is supplied with hot water via a hot water line 101 . The hot water line 101 branches off from the hot water line 23 downstream in front of the brewing valve 50 in the direction of the auxiliary system 100 . Furthermore, the auxiliary system 100 is supplied with water via a water pipe 102 .

The coffee machine also has a controller that controls or regulates the preparation of a hot drink in the coffee machine, which is not shown here.

The following procedure is specified for the operation of a steam and hot water supply 1 of a hot drinks machine, in particular a fully automatic coffee machine:

First, the fully automatic coffee machine is provided with a steam and hot water supply 1, with the steam and hot water supply 1 usually being fed with water by a drinking water network. The steam and hot water supply 1 has a steam generator 10, the steam generator 10 having a container 11 into which water, here water from the drinking water network, can flow via a steam generator supply line 12 and which can be heated by a heater 13, preferably electrically and as a result, steam can be generated from the water, which steam can be discharged from the steam generator 10 from a steam line 14 . Furthermore, the steam and hot water supply 1 has a hot water generator 20, the hot water generator having a container 21 in which the water can be heated, preferably electrically, by a heater 22 and the water can thereby be heated to a predefined preparation temperature.

In a subsequent second method step, the water flows from the drinking water network through a first section 16a of the feed line 16 into the steam generator 10;

In a further, third method step, the water from the drinking water network is preheated in the supply line 16 in the steam generator 10;

In a final fourth method step, the water preheated in the steam generator 10 flows through a second section 16b of the supply line 16 into the hot water generator 20. As a result, beverages can be prepared at a desirable speed—that is to say without a waiting time—in spite of a low output of the heater 22 of the hot water generator 20 without early reheating phases.

A switching valve 30 can optionally be used in the supply line 16 which is connected to the steam generator 10 . Alternatively, the water can also flow directly into the hot water generator 20 via a part 16a′ of the first section 16a of the supply line 16, a water supply line 26 and a part 16b′ of the second section 16b of the supply line 16 through the switching valve 30 . The supply line 16 to the steam generator 10 is then shut off.

Reference List

1 steam and hot water supply

2 taps

3 pump

4 water meters

5 check valve

6 pressure gauge

10 steam generators

11 containers

12 steam generator supply line

13 heating

14 steam line

15 level sensor

16 lead

16a, b branch (of the supply line)

17 heat exchanger

20 hot water generators

21 containers

22 heating

23 hot water line

24 relief valve

25 preheat line

26 water supply line

30 switching valve

40 brew unit

41 beverage line

50 brew valve

61, 62 coffee grinder

70 first drink issue

71 drain

72 check valve 80 diverter valve

90 milk system 91 milk cooler

92 milk packaging

93 first milk line

94 second milk line 100 auxiliary system

101 hot water line

102 water pipe

Claims

Claims Fully automatic coffee machine, which has at least the following: a) a steam and hot water supply (1), with a steam generator (10) that can be fed with water through a steam generator supply line (12) and a hot water generator (20) that can be fed with water; b) a brewing unit (40) in which the hot drink to be prepared can be prepared with water from the hot water generator (20); c) and a beverage outlet (70) from which the prepared beverage can be dispensed into a vessel, characterized in that d) the water which is to be fed to the hot water generator (20) can first be fed through the steam generator (10) or along it is before it can be routed into the hot water generator (20), a heat exchanger (17) being formed in the region of the steam generator (10). Fully automatic coffee machine according to Claim 1, characterized in that a supply line (16) to the hot water generator (20) has a switching valve (30) and a branch (16a) which is routed through the steam generator (10) or along the steam generator (10) and a branch (16a) which goes directly into the hot water generator (20) guided branch (16b). Fully automatic coffee machine according to Claim 2, characterized in that in a first switching position of the switching valve (30), the water to be heated flows via the branch (16a) of the supply line (16) which is routed through the steam generator (10) or along the steam generator (10) in order to then flow preheated into the hot-water generator (20), while the branch (16b) of the supply line (16) leading directly into the hot-water generator (20) is blocked. Fully automatic coffee machine according to claim 2 or 3, characterized in that in a second switching position of the switching valve (30), the water to be heated flows into the hot water generator (20) via the branch (16b) of the supply line (16) which is routed directly into the hot water generator (20). to be heated there by the heater (22) of the hot-water generator (20), while the branch (16a) of the supply line (16) that runs through the steam generator (10) or on the steam generator (10) is shut off. Fully automatic coffee machine according to one of the preceding claims, characterized in that the preheating capacity of the heat exchanger (17) by further Tubular coils, which are formed from the branch (16a) of the supply line (16) in the region of the steam generator (10) that is routed through the steam generator (10) or along the steam generator (10), is formed so that the heat exchanger (17) is like a Coiled tube heat exchanger is working.

6. Fully automatic coffee machine according to one of the preceding claims, characterized in that at least one coffee grinder (61, 62) is provided, which is associated with a storage container for coffee beans.

7. Fully automatic coffee machine according to one of the preceding claims, characterized in that a milk system (90) is provided in which milk foam can be produced from milk with the aid of steam and air.

8. Method for operating a steam and hot water supply (1) of a hot drinks machine, in particular a fully automatic coffee machine according to one of the preceding claims, characterized by the following method steps:

I) Providing the fully automatic coffee machine with a steam and hot water supply (1), the steam and hot water supply (1) being fed with water through a drinking water network and the steam and hot water supply (1) having a steam generator (10) into which water can flow in from the drinking water network via a steam generator supply line (12) and which can be heated by a heater (13), preferably electrically, so that steam can be generated from the water, which steam can be discharged from the steam generator (10) from a steam line (14), and a hot water generator (20) in which the water can be heated, preferably electrically, by a heater (22) and the water can thereby be heated to a predefined preparation temperature.

II) the water flows from the drinking water network into the steam generator (10) through a branch (16a) of a supply line (16) which is guided through the steam generator (10) or along the steam generator (10);

III) preheating of the water from the drinking water network in or on the steam generator (10) in the branch (16a) of the supply line (16) which is guided through the steam generator (10) or along the steam generator (10); 14

IV) the preheated water flows through the branch (16a) of the supply line (16) which is routed through the steam generator (10) or along the steam generator (10) into the hot water generator (20). 9. The method according to claim 8, characterized in that in the supply line

(16), which is connected to the steam generator (10), a switching valve (30) is used, whereby the water flows directly into the hot water generator (20 ) can flow in, while the branch (16a) of the supply line (16) that is routed through the steam generator (10) or along the steam generator (10) is then shut off.