CLEANING DEVICE FOR A BEVERAGE PRODUCTION MACHINE AND METHOD FOR CLEANING A BEVERAGE PRODUCTION MACHINE - Patent application

Abstract

The invention relates to a cleaning device for a beverage maker 15, in particular a coffee machine, comprising a first chamber 4 for receiving a cleaning agent 8, a liquid line system 1, 13 with a water line 1 connectable to a water connection 20 for supplying water, and a drain line 13 connected to the first chamber 4 and connectable to the beverage maker 15, wherein a first piston 6 is insertable into the first chamber 4. By means of said cleaning device the cleaning agent 8 can be completely and homogeneously dissolved in the first chamber 4 and thus transformed into a homogeneous cleaning agent solution, which can be supplied to the beverage maker 15 via the drain line 13 for carrying out the cleaning process. The invention further relates to a method for cleaning a beverage maker 15 by means of such a cleaning device.

Description

[Technical field]

[0001] The present invention relates to a cleaning device for a beverage maker according to the preamble of claim 1 and to a method for cleaning a beverage maker. [Background technology]

[0002] Cleaning devices integrated into beverage producing machines, such as semi-automatic or fully automatic coffee machines, are known from the prior art for cleaning the beverage producing machines. The cleaning devices are used in defined cleaning cycles both during operation and after the beverage producing machine has been switched off, in order to remove, for example, coffee and milk residues and impurities from the coffee and milk carrying components and thus to keep the beverage producing machine always in perfect hygienic conditions. The cleaning cycles can be started manually by an operator or automatically by a control system of the beverage producing machine.

[0003] Cleaning devices for the automatic cleaning of beverage production machines are known from the prior art, in which a cartridge is used in which a cleaning agent is inserted. Such a cleaning device is known, for example, from DE 10 2015 108 438 A1, in which a cartridge filled with a cleaning agent is connected to a liquid supply for hot beverage production in a beverage production machine in order to feed a liquid, in particular water, into the cartridge and dissolve the solid cleaning agent contained in the cartridge. Since the cleaning agent is stored in a sealed state in the cartridge, it can be ensured that the operator of the beverage production machine does not come into contact with the strong cleaning agent. However, dissolution of the cleaning agent in the cartridge in the liquid fed to the cartridge is often incomplete, since the water passed through the cartridge cannot completely convert the solid cleaning agent into a liquid cleaning agent solution. This makes it difficult to accurately meter the amount of cleaning agent required to complete a cleaning cycle or the concentration of cleaning agent required for this purpose in the cleaning agent solution produced by dissolving the cleaning agent in the liquid. Furthermore, cleaning devices with a cleaning agent cartridge have disadvantages in terms of waste avoidance. Because the empty cartridge, which usually has a plastic housing, is intended for a single use, it must be discarded.

[0004] Another device for cleaning a coffee machine is known from DE 10 2011 054 601 A1, which has a water line system with a water tank, a heating device, a brewing unit and a supply pump for conveying water from the water tank through the water line system, in which case the cleaning device comprises a chamber for descaling and / or cleaning agents, which chamber is connectable or connected to the water line system, so that water from the water tank can be conveyed through the chamber by the supply pump of the coffee machine into the water line system of the coffee machine. This cleaning device is intended to achieve complete dissolution and mixing of the descaling and / or cleaning agents, the agents arranged in the chamber being dissolved in an aqueous solution by the introduction and conveyance of water through the chamber, which aqueous solution is conveyed from the chamber into the water line system of the coffee machine, in particular for cleaning the brewing unit and / or the heating device with the cleaning agent solution. However, even with this device it is difficult to accurately meter the amount of cleaning agent required for the cleaning process or the concentration of the cleaning agent in the cleaning agent solution.

[0005] For the precise metering of a specific amount of cleaning agent required for carrying out a cleaning process in a beverage machine, cleaning devices with a metering device for the cleaning agent are known from the prior art, in which a solid cleaning agent, for example in powder, granule, solid or tablet form, is fed to the metering device. From EP 1 210 894 B1, for example, a beverage machine, in particular a coffee machine, is known with a feed device for a solid cleaning agent, in particular in the form of a press body, in which an automatically metering, built-in metering device for the cleaning agent is provided. The dosing device comprises a storage container for the solid cleaning agent and a dosing unit with a movable dosing chamber, through which a defined amount of cleaning agent can be conveyed from the storage container to an outlet.

[0006] A further cleaning system for automatic beverage dispensers, in particular coffee machines, is known from EP 2 584 946 B1, in which the cleaning system comprises a cleaning device for periodically cleaning components that come into contact with the beverage with a cleaning liquid. To produce the cleaning liquid, a solid cleaning agent, which may in particular be in the form of spheres or tablets, is dissolved in the cleaning liquid in the cleaning device. The cleaning device comprises a controlled metering device with a metering barrier, which releases the cleaning spheres or tablets stored in a storage container into a discharge chute with a metering opening. Two counter-rotating metering screws are arranged between the storage container and the discharge chute, via which the cleaning spheres or tablets can be transported individually into the discharge chute.

[0007] Cleaning devices known from the prior art with a metering device for the metered supply of solid cleaning agents allow, on the one hand, a simple and safe handling of the cleaning agent and, on the other hand, an accurate metering of the amount of cleaning agent required for the cleaning process and an accurately metered active substance concentration of the cleaning agent in the cleaning liquid produced by dissolving the solid cleaning agent. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] DE10 2015 108 438A1 [Patent Document 2] DE10 2011 054 601A1 [Patent Document 3] EP1 210 894B1 [Patent Document 4] EP2 584 946B1 Summary of the Invention [Problem to be solved by the invention]

[0009] Based on this, there is a need for a cleaning device for cleaning beverage producing machines, which allows complete dissolution of the cleaning agent, which is supplied by a metering device, for example in powder or tablet form, in a cleaning solution, in particular an aqueous solution of the cleaning agent, in order to produce an optimal concentration of the cleaning agent in the cleaning solution with a uniform concentration distribution over the volume of the dose of the cleaning solution. In particular, complete dissolution or homogeneous mixing of the cleaning agent in the cleaning solution shall be achieved. Furthermore, the consumption of the cleaning agent should be minimized. The cleaning device should be fully automatically controllable by a control device of the beverage producing machine, for example in order to be able to perform a preprogrammed cleaning cycle fully automatically with an exact metering of the amount of cleaning agent required for the cleaning cycle and the optimal concentration of the cleaning agent in the dose of the cleaning solution required for the cleaning cycle. [Means for solving the problem]

[0010] These problems are solved by an apparatus for cleaning a beverage maker having the features of claim 1 and by a method for cleaning a beverage maker having the features of claim 19. Preferred embodiments of the cleaning apparatus and system can be found in the dependent claims.

[0011] The cleaning device according to the invention comprises a first chamber for receiving a cleaning agent, in particular a solid cleaning agent, a liquid line system coupled to the first chamber and comprising a water line connectable to a water connection for supplying water, and a drain line connectable to the first chamber and connectable to a beverage maker, and is provided with a first piston insertable into the first chamber.

[0012] Water can be supplied into the first chamber through the water line in order to dissolve a predetermined amount of cleaning agent in the first chamber in the aqueous cleaning agent solution. The first piston, which can be inserted into the first chamber, thereby allows a good and uniform mixing of the cleaning agent in the aqueous cleaning agent solution, and the piston also closes the cleaning agent access into the first chamber through which the cleaning agent is supplied when the piston is inserted into the first chamber in the working position. When the first piston is in the working position in the first chamber, water can be introduced into the first chamber through the water line in order to dissolve a predetermined amount of cleaning agent in the cleaning agent solution present in the chamber. For this purpose, the first piston is preferably arranged in the first chamber movably between an upper base position, in which the first piston is withdrawn from the first chamber, and a lower working position, in which the first piston is arranged in the first chamber. On the one hand, this allows complete dissolution and uniform mixing of the detergent in the detergent solution as well as a uniform concentration of detergent in a given dose of detergent solution, and on the other hand ensures that no further detergent can enter the chamber during dissolution or mixing of the detergent, since the detergent access of the chamber is closed by the inserted piston.

[0013] In a preferred embodiment of the cleaning device, the first piston is part of a piston unit comprising the first piston, the second piston and a connecting line arranged between the first piston and the second piston and connecting the two pistons. In this case, the second piston is preferably arranged movably in the second chamber, which is arranged upstream of the first chamber in the flow direction of the water supplied through the water line and is connected to the first chamber in a fluid-guiding manner through the connecting line. Through the connecting line, the movement of the second piston in the second chamber is transmitted to the first piston. Thus, the water line is preferably connected to the water inlet connection of the second chamber. This arrangement allows an automatic movement of the first piston and the second piston connected thereto through the connecting lines in the first and second chambers, respectively, when water is introduced into the second chamber through the water line. The pressure of the introduced water moves the second piston in the second chamber from a base position to an operating position, in particular from top to bottom, thereby causing the first piston to also move to its operating position, while water can flow from the second chamber to the first chamber through the connecting line, thereby filling the first chamber with water and dissolving a predetermined amount of cleaning agent present in the first chamber.

[0014] To preload the piston unit, the piston unit preferably comprises a spring element which preloads the second piston in the second chamber in a base position. When water is introduced into the second chamber, the spring element is compressed by the water pressure against its restoring force, bringing the second piston and the first piston into their respective working positions. The spring element is expediently arranged between the first piston and the second piston, in particular around the tubular connecting line, and the spring element is preferably supported on a support in the second chamber. The support is preferably arranged in an end region of the second chamber, in particular at the bottom of the second chamber, and the spring element extends between the support and an end face, in particular the lower end face, of the second piston. With this arrangement, the spring element applies a bias to the first and second pistons in an unloaded state which holds the first and second pistons in their respective base positions with the first piston withdrawn from the first chamber at its base position and the second piston disposed in its base position within the second chamber at its (upper) limit position where the second piston abuts against an (upper) stop of the second chamber.

[0015] In order to ensure a safe movement of the first piston to the working position when water is introduced through the water line and to hold the first piston in this working position during the introduction of water, the second chamber preferably has a larger cross section, in particular a larger diameter, than the first chamber and correspondingly the second piston also has a larger cross section, in particular a larger diameter than the first piston. Due to the larger cross section of the first piston compared to the cross section of the second piston, the reaction force exerted on the first piston, in particular on its lower end face, by the water introduced into the first chamber is smaller than the force exerted on the second piston, in particular on its upper end face, by the water pressure, so that the first and second pistons are each held in their working position as long as water is introduced through the water line.

[0016] Preferably, at least one valve, in particular a shut-off valve and / or a control valve, in particular a pressure control valve and / or a pressure reducing valve, is arranged in the water line. The arrangement of a shut-off valve makes it possible to open and close the water line and thus to introduce water to the washing device and to stop the water supply. The arrangement of a pressure regulating valve and / or a pressure reducing valve in the water line makes it possible to set a predetermined water pressure, preferably in the range of 0.3 MPa to 1 MPa (3 to 10 bar).

[0017] To seal the first and second chambers, the first piston and the second piston preferably each have at least one sealing element, the sealing element of the first piston sealingly abutting against the inner wall of the first chamber and the sealing element of the second piston sealingly abutting against the inner wall of the second chamber.

[0018] For the supply of a predetermined amount of detergent, the first chamber preferably has at least one detergent access, which is expediently arranged in the upper region or at the upper end of the first chamber. Each detergent access comprises an opening in the wall of the first chamber, through which detergent, for example in the form of tablets or spheres or also present as granules, powder or liquid, can be introduced into the first chamber.

[0019] Preferably, in the operative position, the first piston is located in the first chamber to such an extent that access to the first chamber from the cleaning agent inlet opening is blocked, which ensures that no further cleaning agent can be introduced into the first chamber during the introduction of water into the first chamber, thereby ensuring an accurate metering of the amount of cleaning agent in the first chamber and an accurate concentration of cleaning agent in the cleaning agent solution.

[0020] Conveniently, the detergent access is coupled to a detergent dispenser or dosing device for dispensing a predetermined amount of detergent into the first chamber through the detergent access. The detergent dispenser or dosing device is preferably a dispenser by means of which spheres or tablets of detergent stored in a storage container can be individually fed into the detergent access. Such a dosing device is known, for example, from EP 2 584 946 B1. This ensures an accurate metering of the amount of detergent introduced into the first chamber via the detergent access. For example, a predetermined number of detergent spheres or tablets can be introduced into the first chamber, whereby said number of spheres or tablets can be used to produce different concentrations of detergent in a dose of detergent solution predefined by the available volume of the first chamber.

[0021] In order to discharge the cleaning agent solution produced in the first chamber into a discharge line connected to the line system of the beverage machine, the cleaning device preferably comprises a compressed gas line which can be coupled to a compressed gas source. Preferably, the second chamber is connected to the compressed gas line for this purpose, which expediently opens into the second chamber in the upper section or at the top. Alternatively, the compressed gas line can also open into a water line. Via the compressed gas line, compressed gas, for example compressed air, can be introduced into the cleaning device, in particular into the second chamber and via the connecting line into the first chamber, after the water supply has ended, preferably after complete dissolution of the cleaning agent in the cleaning agent solution, in order to push the cleaning agent solution produced in the first chamber into a discharge line connected to the first chamber.

[0022] A shutoff valve and / or a control valve are preferably arranged in the discharge line in order to be able to open or close the discharge line or to be able to set a certain water flow cross-section in the discharge line. The volumetric flow rate of the discharged cleaning agent solution and / or the pressure in the first chamber can be adjusted via the control valve arranged in the discharge line.

[0023] Depending on the position of the shut-off or control valve in the discharge line, the cleaning device can be operated in continuous or batch mode. In continuous operation, the shut-off or control valve in the discharge line is at least partially open while water is continuously fed through the first chamber, so that the cleaning agent in the first chamber is dissolved or mixed in the cleaning agent solution, which is continuously discharged through the open discharge line directly and into the beverage maker. In this case, the use of a control valve in the discharge line is advantageous, since the water cross section in the discharge line can be adjusted by the position of the control valve. By varying the water cross section in the discharge line, the volumetric flow rate of the cleaning agent solution and the concentration of the cleaning agent in the cleaning agent solution can be adjusted. A nozzle arranged in the connecting line ensures that the piston unit, in particular the first piston, is held in a defined operating position, regardless of the position of the control valve in the discharge line.

[0024] In batch operation, the shutoff or control valve in the discharge line is closed while water is supplied into the first chamber through the water line at a certain pressure. A pressure regulating valve and / or a pressure reducing valve is preferably arranged in the water line to set a certain water pressure. Via the water pressure, a precise position of the first piston in the first chamber can be set in batch operation of the cleaning device with the discharge line closed in the working position. The position of the first piston in the working position thus determines the volume in the first chamber in which the cleaning agent solution is generated by dissolving or mixing the cleaning agent. The position of the first piston in the working position thus determines the volume of the dose of cleaning agent solution provided by the cleaning device to perform a cleaning operation. After completion of dissolving or mixing the cleaning agent in the cleaning agent solution, the water supply is stopped by closing the shutoff or control valve in the discharge line, and the dose of cleaning agent solution arranged in the first chamber is pumped into the beverage making machine by introducing compressed gas, e.g. compressed air, into the first chamber while the valve in the discharge line is open. The volumetric flow rate of the cleaning solution delivered to the beverage maker can be regulated by the position of a control valve arranged in the discharge line.

[0025] To control the cleaning process for cleaning the beverage maker, the cleaning device is preferably coupled to a control device of the beverage maker, which automatically starts the cleaning process at a predefined time and / or event, e.g. when the beverage maker is switched on or off or after a predefined number of beverage purchases. Different cleaning processes can also be set or are programmed in the control device, each cleaning process being preferably assigned to a specific dose and / or concentration of a cleaning agent solution. Preferably, the control device is programmable so that an operator can individually set a specific cleaning process and cleaning cycle according to his needs or depending on the beverage to be produced by the beverage maker.

[0026] To control the cleaning device, valves arranged in the water line and in the drain line are coupled to the control device, so that the water line and the drain line can be opened or closed or a certain water pressure in the water line and / or a certain volumetric flow rate of the cleaning solution as it is supplied to the beverage maker can be set by the control device. Furthermore, the control device is preferably also coupled to a compressed gas source and / or to a valve in the compressed gas line to control the supply of compressed gas. If the cleaning agent inlet is coupled to a dispenser or dosing device, the dispenser or dosing device is expediently also controlled by the control device.

[0027] If warm or hot water is supplied to the first chamber in which the solid detergent dissolves, a particularly rapid and complete dissolution of the solid detergent in the detergent solution can be achieved. The water line is therefore preferably connected to a water connection providing hot water, in particular having a temperature between 40°C and 100°C. In this respect, the water connection is conveniently connected to a boiler or flow heater of the beverage maker, which produces hot water for beverage production. In a preferred embodiment, the second chamber is thereby connected via the water line to a boiler or instantaneous water heater providing hot water having a temperature of at least 60°C.

[0028] In the method according to the invention for cleaning a beverage maker by means of a cleaning device, in particular a cleaning device according to the invention and comprising at least one first chamber, a certain amount of cleaning agent is metered into the first chamber, then water is fed into the first chamber via a water line which can be connected to a water connection, so that the cleaning agent dissolves in the cleaning agent solution, and thereafter or during the water supply, the cleaning agent solution is fed to the beverage maker via a drain line connected to the first chamber. It is a proviso that the water fed to the first chamber has a temperature of at least 40°C, preferably higher than 60°C, in particular between 60°C and 100°C. Furthermore, the water fed to the first chamber preferably has a pressure of at least 0.3 MPa (3 bar), preferably between 0.3 MPa and 1 MPa (3 bar and 10 bar), in particular between 0.4 MPa and 0.6 MPa (4 bar and 6 bar).

[0029] In the system, the first chamber is preferably fluidly coupled to the second chamber, and a water line carrying hot water is connected to the second chamber for pumping hot water into the second chamber and into the first chamber. Thus, after a dose of a predetermined amount of cleaning agent, hot water is introduced into the first chamber. Thus, during water supply, the first piston is inserted and held in an operating position in the first chamber. Thus, hot water flows into the first chamber through a connecting line connecting the first and second pistons after the first piston is inserted. To establish a fluid connection between the first and second chambers, a connecting line, particularly a tubular one, preferably extends through the first and second pistons.

[0030] In this case, when water is supplied through the water line, the pressure generated by the introduced water pushes the first piston into the first chamber, and the pressure generated by the introduced water first acts on the second piston, in particular on its upper end surface, and is transmitted by the upper end surface to the first piston. In this case, the cross section of the second piston on which the water pressure acts is preferably larger than the cross section of the first piston on which the reaction force generated by the water flowing into the first chamber through the connecting line acts.

[0031] After the detergent solution has been produced by dissolving a detergent in the hot water supplied to the first chamber, the water supply is first stopped and then the detergent solution is forced out of the first chamber into the drain line by introducing compressed gas, in particular compressed air, into the first chamber and is thereby supplied to the beverage maker. In continuous operation, the detergent solution produced in the first chamber can also be supplied into the drain line already during the water supply.

[0032] As soon as the cleaning solution has been completely displaced to the drain line, the introduction of pressurized gas into the first chamber is stopped, causing the restoring force of the spring element to automatically move the second piston from the first chamber to a base position.

[0033] When the first piston is in a base position outside the first chamber, the cleaning agent access is unblocked for cleaning agent to be introduced into the first chamber, and when the first piston is in an actuated position within the first chamber, the cleaning agent access is blocked, which prevents cleaning agent from entering further into the first chamber while the cleaning agent solution is being generated.

[0034] The system is preferably automatically controlled by a controller that controls, inter alia, a valve in the water line and / or a water connection connected to the water line, a dispenser or dosing device for dispensing a determined amount of cleaning agent, a compressed gas source for introducing compressed gas into the first chamber, and a valve in the exhaust line to perform the above-described steps for producing the cleaning agent solution and performing the cleaning process.

[0035] In this regard, the control device is preferably set up or programmable in such a way that the cleaning process is carried out automatically by the system after a predefined event and / or after a predefined time or at a predefined time, which depends in particular on the operation of the beverage production device, in which case in the cleaning process, in particular the components of the beverage production device that come into contact with the liquid for producing the beverage and / or the beverage produced in the beverage production device, are cleaned with a cleaning agent solution.

[0036] It is further an object of the present invention to provide a beverage production machine, in particular a coffee machine and / or a machine for producing powdered beverages, which is equipped with a cleaning device according to the present invention, preferably via an integrated milk module, also capable of producing hot milk and hot or cold milk foam. Preferably, the cleaning device according to the present invention can be integrated into the beverage production machine or inserted as an exchangeable cleaning module. In particular, the beverage production machine comprises, for example, an extraction device for extracting a hot beverage from ground coffee powder, tea leaves or cocoa powder, and / or a milk module for heating and / or frothing milk, as well as a line system for supplying water to the extraction device and discharging the extracted beverage and / or the heated or frothed milk to an outlet, the cleaning device being expediently coupled to the extraction device and / or the milk module via the line system of the beverage production machine, such that the extraction device and / or the milk module as well as the lines of the line system, through which the beverage and beverage ingredients are conveyed, can be cleaned by a cleaning agent solution produced in the cleaning device during the cleaning process.

[0037] These and other advantages and features of the invention emerge from the examples of embodiments described below with reference to the drawings, in which: FIG. [Brief description of the drawings]

[0038] [Figure 1] 1 is a schematic view of a first embodiment of a cleaning device according to the invention in a base position; [Diagram 2] 2(a) is a schematic diagram of the cleaning apparatus of FIG. 1 in various positions during the initiation and execution of a cleaning cycle; FIG. 2(b) shows the cleaning apparatus in an operating position where water is supplied and the cleaning agent is dissolved in the water to form a cleaning agent solution; FIG. 2(c) shows the cleaning apparatus in an operating position where the cleaning agent solution is discharged; and FIG. 2(d) shows the cleaning apparatus again in the base position ready to receive solid cleaning agent. [Diagram 3]FIG. 2 is a schematic view of a second embodiment of a cleaning device according to the invention in a base position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] The cleaning device shown in FIG. 1 comprises a first chamber 4 in which a first piston 6 is movably arranged and a second chamber 3 in which a second piston 5 is movably arranged. The first chamber 4 and the second chamber 3 are of hollow cylindrical design and each have a cylindrical wall. The first chamber 4 extends vertically from an open upper end to a lower end, the lower end being funnel-shaped and opening into a drain line 13 connected to the first chamber 4. The first piston 6 can be inserted into the first chamber 4 through the open upper end. The second chamber 3 is arranged above the first chamber 4 and also extends between the upper and lower ends, the lower end having a bottom with a central opening. At the upper end of the second chamber 3 a water inlet port is arranged, to which a water line 1 is connected. The water line 1 is part of the fluid line system of the cleaning device, which includes the water line 1 and the drain line 13. The water line 1 is connected to a water connection 20, which in particular provides heated water, preferably having a temperature of at least 40° C., in particular in the range of 60° C. to 100° C. A shut-off valve 10 is arranged in the water line 1, which serves to open and close the water line 1. Instead of or in addition to the shut-off valve, a control valve and / or a pressure reducing valve can also be arranged in the water line 1.

[0040] A stopper 21 is arranged in the region of the upper end of the second chamber 3, which can for example be formed by an annular flange protruding from the wall of the second chamber 3 into the chamber interior. A second piston 5 is arranged movably in the second chamber 3 and can move in the second chamber 3 between a base position a and an operating position b, the upper side of the second piston 5 in the base position a shown in Fig. 1 abutting against the stopper 21 and the lower side of the second piston 5 in the operating position b shown in Fig. 2b abutting against or at least arranged close to the bottom of the second chamber 3.

[0041] 1, the second chamber 3 has a larger cross section, in particular a larger diameter, than the first chamber 4. The second piston 5 therefore also has a larger cross section, in particular a larger diameter, than the first piston 6.

[0042] The first piston 6 and the second piston 5 are each cylindrical or disk-shaped and are connected to each other via a connecting line 18, which extends through the first piston 6 and the second piston 5 and passes through a central opening in the bottom of the second chamber 3. The connecting line 18 thereby provides fluid communication between the first chamber 4 and the second chamber 3. The nozzle 11 is preferably arranged in the connecting line 18.

[0043] A spring element 7, e.g. a spiral spring, is arranged in the second chamber 3, which extends between the underside of the second piston 5 and the bottom of the second chamber 3. As can be seen in FIG. 1, the spring element 7 is arranged in particular around the connecting line 18. The bottom of the second chamber forms a support 19 on which the spring element 7 is supported. The second piston 5 in the second chamber 3 is preloaded in an (upper) base position a by the spring element 7. The first piston 6, which is connected to the second piston 5 via the connecting line 18, is therefore also in an (upper) base position a, in which the first piston 6 is withdrawn from the first chamber 4.

[0044] The first piston 6 and the second piston 5 each have at least one peripheral sealing ring 17, 17' on their outer periphery, and when the second piston 5 is moved from an (upper) base position a to a (lower) working position b in the second chamber 3 and the first piston 6 simultaneously moves into the first chamber 4, the sealing ring 17 of the first piston 6 abuts against the inner side of the wall of the first chamber 4 and the sealing ring 17' of the second piston 5 abuts against the inner side of the wall of the second chamber 3.

[0045] The first piston 6, the second piston 5 as well as the connecting line 18 and the spring element 7 form a piston unit, which is preloaded in a base position a by the spring element 7 and can be moved from the base position a to an operating position b by applying an external force.

[0046] A detergent access 12 is arranged in the region of the upper end of the first chamber 4. The detergent access 12 comprises a lateral opening in the wall of the first chamber 4, not shown here, through which the solid detergent 8, for example in tablet or sphere form, can be introduced into the first chamber 4. To dispense the solid detergent 8 in a predetermined amount into the first chamber 4, the detergent access 12 is connected to a detergent dispenser or dosing device which dispenses the solid detergent 8 into the first chamber 4 through the detergent access 12. Preferably, the solid detergent 8 is in the form of tablets or spheres, which are dispensed individually into the first chamber 4 by the detergent dispenser or dosing device. Several tablets or spheres of solid detergent 8 can also be introduced into the first chamber 4 through the detergent access 12, as shown in FIG. 1 by two detergent spheres 8 arranged at the lower funnel-shaped end of the first chamber 4.

[0047] In the region of the upper end, the compressed gas line 2 opens into the second chamber 3. The compressed gas line 2 comprises a non-return valve 9 and is connected upstream of the non-return valve 9 to a compressed gas source 16 providing a compressed gas, for example compressed air. Instead of compressed air, other food-grade gases can also be provided under pressure by the compressed gas source 16. For this purpose, for example, compressed nitrogen gas or compressed carbon dioxide can be used instead of compressed air. The compressed gas source 16 can for example be formed by a compressor, which draws in ambient air and compresses it to a given pressure.

[0048] A discharge line 13 connected to the lower end of the second chamber 4 is coupled to the beverage maker 15, in particular to the fluid line system of the beverage maker 15, in order to feed the aqueous cleaning agent solution produced in the cleaning device into the fluid line system of the beverage maker 15, in particular into the components of the beverage maker 15 which come into contact with the beverage produced therein and / or the beverage ingredients used therefor. At least one valve is arranged in the discharge line 13 in order to open and close the discharge line 13. Preferably, the discharge line 13 comprises a control valve 14 with an adjustable water flow cross-section.

[0049] The cleaning device shown in Fig. 1 is expediently arranged in the housing of the beverage production machine 15. Preferably, the cleaning device is inserted as an exchangeable module in the housing of the beverage production machine 15. Thereby, the water connection 20 and the compressed gas source 16 are preferably components of the beverage production machine 15 and can be used in the production of a beverage in the beverage production machine for the provision of hot water and compressed gas on the one hand and can supply the cleaning device with hot water via the water line 1 and compressed gas via the compressed gas line 2 on the other hand. In this connection, the water connection 20 can in particular be formed by a boiler or a flow-through water heater of the beverage production machine 15.

[0050] A control device is provided for controlling the cleaning device, which in particular controls the valves 10 and 14 in the water line 1 and the discharge line 13, as well as the supply of compressed gas from a compressed gas source 16 through the compressed gas line 2 and the introduction of solid cleaning agent 8 through the cleaning agent access 12 into the first chamber 4. Thereby, the control device can conveniently be part of the control device of the beverage production machine 15 and is particularly configured such that a cleaning process is initiated by the cleaning device after or at a predetermined time or event depending on the production of a beverage in the beverage production machine 15.

[0051] In Figure 2 the individual steps of a cleaning process which can be carried out by the cleaning apparatus of Figure 1 are shown by different positions of the cleaning apparatus, the steps shown in Figure 2 being carried out successively in the cleaning process in order to supply the cleaning agent solution produced in the cleaning apparatus to the beverage producing machine in continuous or batch operation.

[0052] FIG. 2a shows the cleaning device in a base position a corresponding to the depiction in FIG. 1. To start the cleaning process, with the compressed gas source 16 shut off or the compressed gas line 2 closed and with the valves 10 and 14 closed, a predefined amount of cleaning agent 8, for example a predefined amount of cleaning agent tablets or spheres, is first fed into the first chamber 4 through the cleaning agent access 12. Then, as shown in FIG. 2b, the valve 10 in the water line 1 is opened. Furthermore, the control valve 14 in the discharge line 13 is at least partially opened and, in particular, set to a predefined water cross section. As a result, preferably hot water, for example with a temperature of 40° C. to 80° C. and a predefined pressure, preferably higher than 0.3 MPa (3 bar), in particular 0.4 MPa to 4 MPa (4 bar to 10 bar), in particular depending on the water pressure provided by the public water supply, flows from the water line 1 into the upper region of the second chamber 3. Thereby, the water pressure can be set to a specific value, if necessary, by a pressure regulating or reducing valve in the water line 1. As a result of the pressure of the incoming water acting on the upper end face of the second piston 5, the second piston 5 in the second chamber 3 is moved from the base position a shown in FIG. 2a to the working position b shown in FIG. 2b, in which the second piston 5 in the second chamber 3 is located near the bottom. Since the second piston 5 is connected to the first piston 6 via the connecting line 18, this also moves the first piston 6 from the base position a shown in FIG. 2a, in which the first piston 6 is withdrawn from the first chamber 4, to the working position b shown in FIG. 2b, in which the first piston 6 is located in the first chamber 4 at a predetermined height. This causes the first piston 6 to be located above a sphere of cleaning agent 8 located in the first chamber 4, as shown in FIG. 2b. By moving the first piston 6 to the operating position b shown in FIG. 2b, the cleaning agent access 12, in particular the opening in the wall of the first chamber 4, is closed and cleaning agent can no longer enter the first chamber 4 in the area below the first piston 6.

[0053] The water flowing into the second chamber 3 via the water line 1 flows through the nozzle 11 in the connecting line 18 into the first chamber 4 which is connected in a fluid-guiding manner to the second chamber 3 via the connecting line 18. Due to the larger cross-section of the first piston 6 compared to the cross-section of the second piston 5, the reaction force exerted on the first piston 6 by the water introduced into the first chamber 4 is smaller than the force exerted on the second piston 5 by the water pressure, so that the first piston 6 and the second piston 5, respectively, are held in their working position b as long as water is introduced via the water line 1. The nozzle 11 thereby ensures a sufficiently high pressure upstream of the nozzle 11 to maintain the piston unit in its working position b.

[0054] When water flows into the first chamber 4 in the area under the first piston 6, the spheres of detergent 8 in the first chamber 4 dissolve and form an aqueous detergent solution. The concentration of detergent 8 in the detergent solution is determined by the amount of detergent in the first chamber 4 and the volumetric flow rate of the passing water, which is determined by the set water cross section in the discharge line 13.

[0055] The closed detergent access 12 ensures that no further detergent can be added to the detergent solution in the first chamber 4 while the detergent 8 is being dissolved.

[0056] Thus, for a given water flow cross section in the discharge line 13 and a given amount of cleaning agent 8 in the first chamber 4, a given cleaning agent concentration is established in the cleaning agent solution, which flows continuously into the discharge line 13 and is thereby conveyed into the beverage maker 15, in particular into the fluid line system of the beverage maker 15. There, in particular the components of the beverage maker 15 which come into contact with the beverage and / or beverage ingredients (e.g. coffee powder, milk or milk foam, etc.) during the production of the beverage, are cleaned by the aqueous cleaning agent solution.

[0057] The temperature and pressure of the water introduced into the first chamber 4 ensure complete dissolution of the solid detergent 8 in the detergent solution. After the transfer of a sufficient amount of aqueous detergent solution for the cleaning process, the valve 10 of the water line 1 is closed, thereby stopping the water supply. Then, as shown in FIG. 2c, compressed gas, in particular compressed air, is introduced into the upper area of ​​the second chamber 3 via the compressed gas line 2, the pressure of the compressed gas being preferably higher than 0.1 MPa (1 bar), in particular between 0.15 MPa and 0.3 MPa (1.5 bar and 3 bar). The pressure of the introduced compressed gas, flowing from the second chamber 3 into the first chamber 4 via the connecting line 18, pushes the remaining amount of detergent solution still in the first chamber 4 into the discharge line 13.

[0058] Instead of the continuous operation described above, the cleaning device can also be operated in a batch mode, in which a predetermined dose of a cleaning agent solution having a predetermined concentration of the cleaning agent is first produced in the first chamber and then fed to the beverage maker 15 through the discharge line 13. In this batch operation, the volume of the dose of cleaning agent solution produced is determined by the position of the first piston 6 in the first chamber 4 in the working position b, since this position determines the volume of the first chamber 4 under the first piston 6 in which the solid cleaning agent 8 is located. In this regard, the position of the first piston 6 in the first chamber 4 in the working position can be adjusted by the pressure of the water introduced through the water line 1 when the discharge line 13 is closed. Thus, the volume of the dose of aqueous cleaning agent solution in the first chamber 4 can be varied by the water pressure. Thus, when the solid cleaning agent 8 is dissolved, a predetermined concentration of cleaning agent 8 is produced in the aqueous cleaning agent solution, which concentration is determined by the predetermined amount of cleaning agent 8 in the first chamber 4 and the volume of the first chamber 4 below the piston 6.

[0059] After dissolution of the cleaning agent 8 in the cleaning solution, with the valve 10 in the water line 1 closed, the produced dose of cleaning agent solution is fed via the discharge line 13 to the beverage maker 15 by opening the discharge line 13, in particular the valve 14, and compressed gas is introduced by the compressed gas line 2 into the first chamber 4. The dose of aqueous cleaning agent solution has a predefined concentration of the cleaning agent in the cleaning agent solution, whereby the concentration can be varied by the amount of cleaning agent 8 fed into the first chamber 4 and by the water pressure during production of the cleaning agent solution. A control valve 14 arranged in the discharge line 13 advantageously allows the setting of a predefined volumetric flow rate of the aqueous cleaning agent solution from the first chamber 4 to the discharge line 13 when the cleaning agent solution is discharged.

[0060] After the transfer of the cleaning agent solution from the first chamber 4 to the fluid line system of the beverage maker 15 in a continuous or batch operation of the cleaning device, the cleaning process is completed and the cleaning device is returned to its base position a by stopping the supply of compressed gas via the compressed gas line 2 with the valve 10 closed (by switching off the compressed gas source 16 or by closing the compressed gas line 2 by a valve). This causes the piston unit, including the first piston 6, the second piston 5 and the connecting line 18, to move again to the base position a shown in Fig. 2d. In this case, the piston unit is automatically brought to the base position a by the restoring force of the spring element 7, in which base position a the second piston 5 abuts against the stopper 21 of the second chamber 3 and the first piston 6 is withdrawn from the first chamber 4 at least to such an extent that the first piston 6 is located above the cleaning agent access 12, in particular above the opening in the wall of the first chamber 4, as shown in Fig. 2d. In this base position a of the cleaning device, the first chamber 4 is again available for receiving a predetermined amount of solid cleaning agent 8, in particular for receiving a predetermined number of spheres or tablets of cleaning agent 8, and the cleaning device can be used for a next cleaning process.

[0061] Figure 3 shows a second embodiment of the cleaning device according to the invention in the base position. This embodiment corresponds to the cleaning device of Figure 1 except for the arrangement of the compressed gas line 2, which in the embodiment of Figure 3 does not open into the second chamber 3 but into the water line 1. In this case, an additional non-return valve 9' is arranged in the water line 1 in order to prevent the compressed gas from exiting the compressed gas line 2 in the direction of the water connection 20. In this embodiment, compressed gas from a compressed gas source 16 is pumped through the compressed gas line 2 into the water line 1 in order to push the cleaning agent solution arranged in the first chamber 4 into the discharge line 13 when the valve 10 in the water line 1 is open, after the cleaning agent has been completely dissolved or mixed in the cleaning agent solution. The embodiment of Figure 3 is distinguished from the embodiment of Figure 1 by a simpler construction of the second chamber 3.

[0062] The cleaning device according to the invention allows for a fast and complete dissolution of the solid cleaning agent in the aqueous cleaning solution, in particular by the pressure and temperature of the water supplied via the water line 1. Furthermore, an accurate dosage of the amount of solid cleaning agent 8 and maintenance of a predefined concentration of the cleaning agent in the aqueous cleaning solution are guaranteed, the exact concentration of the cleaning agent being controllable in particular by the water pressure of the water supplied through the water line 1. The cleaning device has a simple and compact design and does not require a motor control for moving the cleaning device from the base position b to the working position b and vice versa.

Claims

1. A cleaning device for a beverage maker (15), in particular a coffee machine, comprising a first chamber (4) for receiving a cleaning agent (8), a liquid line system (1, 13) with a water line (1) connectable to a water connection (20) for supplying water, and a drain line (13) connected to the first chamber (4) and connectable to the beverage maker (15), characterized by a first piston (6) insertable into the first chamber (4).

2. 2. The cleaning device according to claim 1, characterized in that the first piston (6) is movable between a base position (a) in which the first piston (6) is withdrawn from the first chamber (4) and an operating position (b) in which the first piston (6) is located within the first chamber (4).

3. 3. The cleaning device according to claim 1 or 2, characterized in that the first piston (6) is part of a piston unit (5, 6, 18) including the first piston (6), a second piston (5) and a connecting line (18) arranged between the first piston (6) and the second piston (5), and the movement of the second piston (5) is transmitted to the first piston (6) via the connecting line (18).

4. 4. The cleaning device according to claim 3, characterized in that the second piston (5) is movably arranged in a second chamber (3), the second chamber (3) being arranged upstream of the first chamber (4) and in fluid communication with the first chamber (4) via the connecting line (18), and a nozzle (11) is preferably arranged in the connecting line (18).

5. 4. The cleaning device according to claim 3, characterized in that the piston unit (5, 6, 18) comprises a spring element (7) arranged between the first piston (6) and the second piston (5), the spring element (7) in an unloaded state applying a pretension to the first piston (6) that maintains the first piston (6) in a base position (a) in which the first piston (6) is withdrawn from the first chamber (4).

6. 5. A cleaning device according to claim 4, characterized in that the second chamber (3) has a larger cross section than the first chamber (4) and / or the second piston (5) has a larger cross section than the first piston (6).

7. 2. The cleaning device according to claim 1, characterized in that the first chamber (4) comprises a cleaning agent access (12) comprising an opening in the wall of the first chamber (4).

8. 8. The cleaning device according to claim 7, wherein the first piston (6) in the operating position (b) is arranged in the first chamber (4) to such an extent that the cleaning agent access (12) is blocked.

9. 8. The cleaning device according to claim 7, characterized in that the cleaning agent access (12) is connected to a cleaning agent dispenser or dosing device which dispenses the cleaning agent through the cleaning agent access (12) into the first chamber (4).

10. 4. The cleaning device according to claim 3, characterized in that the second chamber (3) is connected to a compressed gas line (2), which can be coupled to a compressed gas source (16), and which opens into the second chamber (3) in an upper section or at the upper side or into the water line (1).

11. A beverage producing machine (15), in particular a coffee machine and / or a machine for producing powdered beverages, comprising a cleaning device according to claim 1.

12. 12. A method for cleaning a beverage maker (15) by means of a cleaning device, in particular a cleaning device according to any one of claims 1 to 11, comprising a first chamber (4) and a first piston (6) which can be introduced into said first chamber, wherein a specific amount of a preferably solid cleaning agent (8) is metered into said first chamber (4), and then water is supplied into said first chamber (4) via a water line (1) which can be connected to a water connection (20) while said piston (6) is inserted into an operating position in said first chamber (4), whereby said cleaning agent (8) is dissolved and / or mixed in a cleaning agent solution, and said cleaning agent solution is supplied to said beverage maker (15) via a discharge line (13) connected to said first chamber (4).

13. 13. The method according to claim 12, wherein the water supplied to the first chamber (4) has a temperature of at least 40°C, preferably higher than 60°C, in particular between 60°C and 100°C.

14. 13. The method according to claim 12, characterized in that the first chamber (4) is fluidly connected to the second chamber (3), the water conduit (1) is connected to the second chamber (3) for delivering water to the second chamber (3) and to the first chamber (4), and after dispensing the cleaning agent into the first chamber (4), the first piston (6) is introduced into the first chamber (4) in an operating position, and after the first piston (6) has been introduced into the first chamber (4), the water is introduced into the first chamber (4) through a connecting line (18).

15. 15. The method according to claim 14, characterized in that the first piston (6) is coupled to the second piston (5) via the connecting line (18), the second piston (5) is movably arranged in the first chamber (3), the first chamber (4) is fluidly coupled to the second chamber (3) via the connecting line (18), the water line (1) is connected to the second chamber (3), the first piston (6) is pushed into the first chamber (4) by a pressure generated by the water introduced when water is supplied through the water line (1), and the pressure generated by the introduced water acts on the second piston (5) and is transmitted to the first piston (6) by the second piston (5).

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