Cleaning device for a beverage preparation machine and method for cleaning a beverage preparation machine

Description

[0001] The invention relates to a cleaning device for a beverage preparation machine according to claim 1 and to a method for cleaning a beverage preparation machine according to claim 10.

[0002] For cleaning beverage preparation machines, such as semi- or fully automatic coffee machines, cleaning devices integrated into the beverage preparation machine are known from the prior art. The cleaning device is used in predefined cleaning cycles both during operation and after the beverage preparation machine has been switched off. For example, it can clean the coffee and milk-carrying components of coffee and milk residues and contaminants, thus keeping the beverage preparation machine under perfect hygienic conditions at all times. The cleaning cycles can either be started manually by an operator or initiated automatically by a control system of the beverage preparation machine.

[0003] For the automatic cleaning of beverage preparation machines, cleaning devices are known from the prior art, in which a cartridge with a cleaning agent inserted therein is used. 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 preparation in the beverage preparation machine in order to direct a liquid, in particular water, into the cartridge and dissolve the solid cleaning agent contained in the cartridge. This ensures that an operator of the beverage preparation machine does not come into contact with the aggressive cleaning agent, as it is stored in a sealed manner in the cartridge.However, the dissolution of the cleaning agent contained in the cartridge in the liquid supplied to the cartridge is often incomplete because the water flowing through the cartridge cannot completely convert the solid cleaning agent into a liquid cleaning solution. This makes it difficult to accurately dose the amount of cleaning agent required to complete a cleaning cycle or to achieve the required concentration of the cleaning agent in a cleaning solution created by dissolving the cleaning agent in the liquid. Furthermore, cleaning devices with cleaning agent cartridges have disadvantages from the point of view of waste prevention. This is because the emptied cartridges, which usually have a plastic housing, are intended for single use and must be disposed of.

[0004] US 5,551,988 discloses a method for cleaning a brewing device, in particular a coffee machine, wherein, for the cleaning process, water is supplied from a water container or from an external water connection via a supply line to the water connection of a brewing cylinder, and in at least one cleaning phase, water is conducted from the brewing cylinder to areas outside the brewing cylinder. In a further cleaning phase, chemical and / or biological cleaning can be carried out. For this purpose, the brewing cylinder is pivoted beneath a funnel, wherein a cleaning agent in tablet, powder, or liquid form is introduced into the brewing cylinder through a powder chute. The brewing cylinder is then pivoted back into a rinsing position. After the pump has pumped water into the brewing cylinder, the cleaning agent is allowed to act for some time.

[0005] CH 709 738 A1 shows an application device for a descaling agent, with which a descaling agent can be supplied to a drinks machine, in particular a coffee machine, wherein the liquid descaling agent is pressed out of a container into an outlet line connected to the drinks machine by means of a pre-tensioned piston.

[0006] Another descaling device is known from US 2014 / 0060338 A1, wherein the descaling device comprises a storage container with a housing containing a water inlet fed by a water source to a storage chamber with a water-soluble descaling agent accommodated therein, and the storage container has a bottom chamber connected to the storage chamber in a fluid-conducting manner for collecting the descaling agent dissolved by the water, into which a capillary line for discharging the solution opens.

[0007] Another device for cleaning a coffee machine with a water tank, a heating device, a brewing unit and a water pipe system with a feed pump for conveying water from the water tank through the water pipe system is known from DE 10 2011 054 601 A1, wherein the cleaning device comprises a chamber for a descaling and / or cleaning agent, which can be connected or switched on to the water pipe system, so that the water from the water tank can be conveyed through the chamber into the water pipe system of the coffee machine by means of the feed pump of the coffee machine.This cleaning device is intended to enable complete dissolution and mixing of the descaling and / or cleaning agent by dissolving the agent contained in the chamber into an aqueous solution by introducing and transporting water through the chamber, and then conveying the aqueous solution from the chamber into the coffee machine's water supply system, in particular to clean the brewing unit and / or the heating device with the cleaning solution. However, even with this device, it is difficult to precisely measure the amount of cleaning agent required for a cleaning process or the concentration of the cleaning agent in the cleaning solution.

[0008] For the precise dosing of a specific amount of a cleaning agent required for carrying out a cleaning process in a beverage preparation machine, cleaning devices with a dosing device for the cleaning agent are known from the prior art, wherein a solid cleaning agent, for example in powder, granulate, solid, or tablet form, is fed to the dosing device. EP 1 210 894 B1, for example, discloses a beverage machine, in particular a coffee machine, with an inlet device for solid cleaning agent, in particular in pressed body form, in which an automatically dosing, self-contained dosing 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 predetermined amount of the cleaning agent can be conveyed from the storage container into an outlet.

[0009] Another cleaning system for a beverage vending machine, in particular a coffee machine, is known from EP 2 584 946 B1. The cleaning system includes a cleaning device for periodically cleaning the components that come into contact with the beverages using a cleaning fluid. To produce the cleaning fluid, a solid cleaning agent, which may in particular be in the form of a ball or tablet, is dissolved in the cleaning fluid in the cleaning device. The cleaning device comprises a controlled dosing device with a dosing gate that releases the cleaning balls or tablets, which are stored in a storage container, into a dispensing chute with a dosing opening. Two counter-rotating dosing screws are arranged between the storage container and the dispensing chute, through which the cleaning balls or tablets can be conveyed individually into the dispensing chute.

[0010] The cleaning devices known from the prior art with a dosing device for the dosed supply of a solid cleaning agent enable, on the one hand, simple and safe handling of the cleaning agent as well as precise dosing of the amount of cleaning agent required for a cleaning process and a precisely dosed active ingredient concentration of the cleaning agent in a cleaning liquid which is produced by dissolving the solid cleaning agent.

[0011] Based on this, there is a need for a cleaning device for cleaning beverage preparation machines that enables complete dissolution of a cleaning agent, which is supplied, for example, in powder or tablet form by means of a dosing device, in a cleaning agent solution, in particular an aqueous solution of the cleaning agent, in order to create an optimal concentration of the cleaning agent in the cleaning agent solution with a homogeneous concentration distribution over the volume of a dose of the cleaning agent solution. In particular, complete dissolution or homogeneous mixing of the cleaning agent in the cleaning agent solution should be achieved. Furthermore, the consumption of cleaning agent should be minimized.The cleaning device should be fully automatically controllable by a control device of the beverage preparation machines in order, for example, to be able to carry out pre-programmed cleaning cycles fully automatically with an exact dosage of the amount of cleaning agent required for the cleaning cycle and an optimal concentration of the cleaning agent in a dose of a cleaning agent solution required for the cleaning cycle.

[0012] These objects are achieved with the device for cleaning a beverage preparation machine having the features of claim 1 and with the method for cleaning a beverage preparation machine having the features of claim 10. Preferred embodiments of the cleaning device and the method can be found in the dependent claims.

[0013] The cleaning device according to the invention comprises a first chamber for receiving a cleaning agent, in particular a solid one, and a liquid line system coupled to the first chamber with a water line connectable to a water connection for supplying water and a drain line connected to the first chamber, which can be connected to the beverage preparation machine, wherein a first piston insertable into the first chamber is provided.

[0014] Water can be fed into the first chamber through the water line in order to dissolve a predetermined amount of cleaning agent contained therein in an aqueous cleaning solution. The first piston, which can be inserted into the first chamber, enables good and homogeneous mixing of the cleaning agent in the aqueous cleaning solution and the piston also closes off a cleaning agent access into the first chamber through which the cleaning agent is supplied when the piston is inserted into the first chamber in an operating position. When the first piston is in its operating position in the first chamber, water can be fed into the first chamber via the water line in order to dissolve the amount of cleaning agent contained in the chamber in the cleaning solution.For this purpose, the first piston is arranged in the first chamber, movable between an upper basic position, in which the first piston is extended from the first chamber, and the lower operating position, in which the first piston is located in the first chamber. This enables, on the one hand, complete dissolution and homogeneous mixing of the cleaning agent in the cleaning solution, as well as a homogeneous concentration of the cleaning agent in a predetermined dose of the cleaning solution. On the other hand, it ensures that no further cleaning agent can enter the chamber during dissolution or mixing of the cleaning agent, because the cleaning agent access to the chamber is closed by the inserted piston.

[0015] In a preferred embodiment of the cleaning device, the first piston is a component of a piston unit which comprises the first piston, a second piston, and a connecting line which is arranged between the first piston and the second piston and connects the two pistons. The second piston is preferably arranged such that it can move in a second chamber, the second chamber being arranged upstream of the first chamber as seen in the flow direction of the water supplied via the water line, and being in fluid communication with the first chamber via the connecting line. A movement of the second piston in the second chamber is transmitted to the first piston via the connecting line. The water line is preferably connected to a water inlet nozzle of the second chamber. This arrangement enables automatic movement of the first piston and the second piston connected to it via the connecting line in the first and second chambers.the second chamber 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 basic position to an operating position, in particular from top to bottom. The first piston also moves into its operating position, while the water can flow through the connecting line from the second chamber into the first chamber to fill the first chamber with water and dissolve the amount of cleaning agent contained therein.

[0016] To preload the piston unit, it preferably comprises a spring element which preloads the second piston in the second chamber in its basic position. When water is introduced into the second chamber, the spring element is compressed by the water pressure against its restoring force, whereby the second piston and the first piston are brought into their respective operating positions. The spring element is expediently arranged between the first piston and the second piston and 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 on a base of the second chamber, wherein the spring element extends between the support and an end face, in particular the lower end face, of the second piston.By this arrangement, the spring element in an unloaded state exerts a preload on the first and the second piston, which holds the first and the second piston in their respective home positions, wherein the first piston in its home position is pulled out of the first chamber and the second piston in its home position within the second chamber in an (upper) limit position in which the second piston rests against an (upper) stop of the second chamber.

[0017] In order to ensure a secure movement of the first piston into its operating position when water is introduced through the water line and to hold the first piston in this operating position during the introduction of water, the second chamber preferably has a larger cross-section and in particular a larger diameter than the first chamber and accordingly the second piston preferably also has a larger cross-section and 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 counterforce exerted by the water introduced into the first chamber on the first piston, in particular on its lower end face, is smaller than the force exerted by the water pressure on the second piston, in particular on its upper end face, whereby the first and second pistons are each held in their operating position as long as water is introduced via the water line.

[0018] 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 reducer, is arranged in the water line. The provision of a shut-off valve enables the water line to be opened and closed, thereby introducing water into the cleaning device and stopping the water supply. The provision of a pressure control valve and / or a pressure reducer in the water line enables the setting of a predetermined water pressure, which is preferably in the range of 3 to 10 bar.

[0019] To seal the first and the second chamber, the first piston and the second piston preferably each have at least one sealing element, wherein the sealing element of the first piston sealingly abuts an inner wall of the first chamber and the sealing element of the second piston sealingly abuts an inner wall of the second chamber.

[0020] To supply a predetermined amount of cleaning agent, the first chamber has at least one cleaning agent inlet, wherein the cleaning agent inlet is expediently located in an upper region or at an upper end of the first chamber. The or each cleaning agent inlet comprises an opening in a wall of the first chamber through which the cleaning agent, which may be in the form of tablets or spheres, or also as granules, powder, or liquid, can be introduced into the first chamber.

[0021] According to the invention, the first piston, in its operating position, is located far enough in the first chamber that access from the opening of the cleaning agent inlet into the first chamber is blocked. This ensures that no additional cleaning agent can be introduced into the first chamber while water is being introduced into the first chamber, thereby ensuring precise dosing of the cleaning agent quantity in the first chamber and precise concentration of the cleaning agent in the cleaning solution.

[0022] According to the invention, the cleaning agent inlet is coupled to a cleaning agent dispenser or a dosing device in order to dose a predetermined amount of cleaning agent through the cleaning agent inlet into the first chamber. The cleaning agent dispenser or dosing device is preferably a dispenser with which balls or tablets of the cleaning agent, which are stored in a reservoir, can be individually fed to the cleaning agent inlet. Such a dosing device is known, for example, from EP 2 584 946 B1. This ensures precise dosing of the amount of cleaning agent introduced into the first chamber via the cleaning agent inlet.It is possible to introduce a predefined number of cleaning agent balls or tablets into the first chamber, so that different concentrations of the cleaning agent can be produced in a dose of the cleaning agent solution determined by the available volume of the first chamber using the number of balls or tablets.

[0023] In order to discharge the cleaning agent solution produced in the first chamber into a drain line connected to the line system of the beverage preparation machine, the cleaning device preferably comprises a compressed gas line which can be coupled to a compressed gas source. For this purpose, the second chamber is preferably connected to the compressed gas line, wherein the compressed gas line expediently opens into the second chamber in an upper section or at an upper side. Alternatively, the compressed gas line can also open into the water line. After the water supply has ended and preferably after the cleaning agent has completely dissolved in the cleaning agent solution, a compressed gas (compressed gas), e.g.Compressed air is introduced into the cleaning device and in particular into the second chamber and via the connecting line into the first chamber in order to press the cleaning solution produced in the first chamber into the drain line connected to the first chamber.

[0024] A shut-off valve and / or a control valve is preferably arranged in the drain line to open and close the drain line or to adjust a specific flow cross-section in the drain line. A control valve arranged in the drain line can be used to adjust the volume flow of the discharged cleaning solution and / or the pressure in the first chamber.

[0025] The cleaning device can be operated in continuous or batch mode, depending on the position of the shut-off or control valve in the drain line. During continuous operation, the shut-off or control valve in the drain line is at least partially open, while water is continuously passed through the first chamber, dissolving or mixing the cleaning agent in the first chamber into a cleaning solution, and the cleaning solution is discharged directly and continuously through the open drain line to the beverage preparation machine. The use of a control valve in the drain line is advantageous because the flow cross-section in the drain line can be adjusted by adjusting the position of the control valve.By changing the flow cross-section in the drain line, the volume flow of the cleaning solution and the concentration of the cleaning agent in the solution can be adjusted. A nozzle arranged in the connecting line ensures that the piston unit, and in particular the first piston, is held in a predetermined operating position, regardless of the position of the control valve in the drain line.

[0026] During batch operation, the shut-off or control valve in the drain line is closed, while water at a predetermined pressure is fed through the water line into the first chamber. To set a specific water pressure, a pressure control valve and / or a pressure reducer is preferably arranged in the water line. During batch operation of the cleaning device, with the drain line closed in the operating position, the exact position of the first piston in the first chamber can be set using the water pressure. The position of the first piston in the operating position determines the volume in the first chamber in which the cleaning solution is generated by dissolving or mixing the cleaning agent. The position of the first piston in the operating position therefore determines the volume of a dose of the cleaning solution that is made available by the cleaning device to carry out a cleaning process.Once the cleaning agent has been dissolved or mixed in the cleaning solution, the water supply is stopped by closing the shut-off or control valve in the drain line. The dose of cleaning solution contained in the first chamber is directed to the beverage preparation machine by introducing a compressed gas, e.g., compressed air, into the first chamber with the valve in the drain line open. The volume flow of the cleaning solution supplied to the beverage preparation machine can be adjusted by adjusting the position of a control valve located in the drain line.

[0027] To control a cleaning process for cleaning the beverage preparation machine, the cleaning device is preferably coupled to a control device of the beverage preparation machine, which automatically initiates a cleaning process at predetermined times and / or events, e.g., switching the beverage preparation machine on or off or after a predetermined number of beverages have been dispensed. Various cleaning processes can also be programmed in the control device, with a specific dosage and / or concentration of the cleaning agent solution preferably being assigned to each cleaning process. The control device is preferably programmable, so that an operator can set specific cleaning processes and cleaning cycles individually according to their needs or depending on the beverages produced with the beverage preparation machine.

[0028] To control the cleaning device, the valves arranged in the water line and in the drain line are coupled to the control device. This allows the water line and the drain line to be opened and closed, or the control device can set a specific water pressure in the water line and / or a specific volume flow of the cleaning agent solution when feeding it to the beverage preparation machine. Furthermore, the control device is preferably also coupled to the compressed gas source and / or a valve in the compressed gas line to control the supply of the compressed gas. If the cleaning agent inlet is coupled to a dispenser or a dosing device, the dispenser or dosing device is expediently also controlled by the control device.

[0029] A particularly rapid and complete dissolution of solid cleaning agent in the cleaning agent solution can be achieved if warm or hot water, in which the solid cleaning agent dissolves, is supplied to the first chamber. Therefore, the water line is preferably coupled to a water connection that provides hot water, in particular at a temperature between 40°C and 100°C. The water connection is expediently coupled to a boiler or a continuous-flow heater of the beverage preparation machine, which generates hot water for beverage preparation. In a preferred embodiment, the second chamber is connected via the water line to the boiler or the continuous-flow heater, which provides hot water at a temperature of at least 60°C.

[0030] In the method for cleaning a beverage preparation machine with a cleaning device, which is in particular a cleaning device according to the invention and which comprises at least a first chamber, a specific amount of a cleaning agent is metered into the first chamber and water is then fed into the first chamber via a water line connectable to a water connection, whereby the cleaning agent dissolves in a cleaning agent solution. Afterward or during the water supply, the cleaning agent solution is fed to the beverage preparation machine via a drain line connected to the first chamber. It is provided that the water fed into the first chamber has a temperature of at least 40°C, preferably more than 60°C and in particular between 60°C and 100°C.Furthermore, the water fed into the first chamber preferably has a pressure of at least 3 bar, preferably between 3 bar and 10 bar and in particular between 4 bar and 6 bar.

[0031] In one embodiment of the cleaning device, the first chamber is preferably fluidically coupled to a second chamber, wherein the water line which carries the warm water is connected to the second chamber in order to conduct the warm water into the second chamber and into the first chamber. The warm water is introduced into the first chamber after a certain amount of cleaning agent has been dosed. During the water supply, the first piston is inserted into its operating position in the first chamber and held there. After the first piston has been inserted, the warm water flows into the first chamber through the connecting line which connects the first and second pistons. The connecting line, which is in particular tubular, preferably extends through the first and second pistons in order to establish a fluidic connection between the first chamber and the second chamber.

[0032] When water is supplied through the water line, the pressure generated by the introduced water pushes the first piston into the first chamber. The pressure generated by the introduced water initially acts on the second piston, in particular its upper end face, and is transferred from there to the first piston. The cross-section of the second piston, upon which the pressure of the water acts, is preferably larger than the cross-section of the first piston, upon which a counterpressure acts, generated by the water flowing into the first chamber via the connecting line.

[0033] After the cleaning solution is generated by dissolving the cleaning agent in the warm water supplied to the first chamber, the water supply is first stopped. Then, by introducing a pressurized gas, in particular compressed air, into the first chamber, the cleaning solution is forced from the first chamber into the drain line, thereby feeding it to the beverage preparation machine. In continuous operation, the cleaning solution generated in the first chamber can also be fed into the drain line while the water supply is still running.

[0034] As soon as the cleaning solution has been completely transferred into the drain line, the introduction of the compressed gas into the first chamber is stopped, whereby the second piston moves automatically out of the first chamber into its home position due to the restoring force of the spring element.

[0035] When the first piston is in its home position outside the first chamber, the detergent access through which the detergent is introduced into the first chamber is open. The detergent access is blocked when the first piston is in an operating position inside the first chamber. This prevents detergent from entering the first chamber during the generation of the detergent solution.

[0036] The cleaning device is preferably controlled automatically by a control device which, in particular, controls a valve in the water line and / or a water connection connected thereto, a dispenser or a dosing device for dispensing the specific amount of cleaning agent, a compressed gas source for introducing a compressed gas into the first chamber and a valve in the drain line in order to carry out the above-described steps for preparing a cleaning agent solution and for carrying out a cleaning process.

[0037] The control device is preferably configured or programmable such that, after predetermined events, which are in particular dependent on operation of the beverage preparation device, and / or after or at predetermined times, a cleaning process is automatically carried out by the cleaning device, wherein, in the cleaning process, in particular those components of the beverage preparation device which come into contact with liquids for producing a beverage and / or with a beverage produced in the beverage preparation device are cleaned with the cleaning agent solution.

[0038] The invention further relates to a beverage preparation machine, in particular a coffee machine and / or a machine for producing a powdered beverage, in which hot milk and warm or cold milk foam can also be prepared, preferably via an integrated milk module, wherein the beverage preparation machine is equipped with a cleaning device according to the invention. A cleaning device according to the invention is preferably integrated into the beverage preparation machine or can be introduced as an exchangeable cleaning module. The beverage preparation machine comprises, in particular, a brewing device for brewing a hot beverage, e.g.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 brewing device and for discharging the brewed beverage and / or the heated or frothed milk to an outlet, wherein the cleaning device is expediently coupled to the brewing device and / or to the milk module via the line system of the beverage preparation machine in order to be able to clean the brewing device and / or the milk module as well as the lines of the line system in which the beverages and beverage ingredients are transported with the cleaning agent solution generated in the cleaning device during a cleaning process.

[0039] These and other advantages and features of the invention will become apparent from the embodiment described below with reference to the drawings, in which: Fig. 1:a schematic representation of a first embodiment of a cleaning device according to the invention in a basic position; Fig. 2: schematic representations of the cleaning device of Figure 1 in different positions during the initiation and execution of a cleaning cycle, whereby Figure 2(a) shows the cleaning device in the basic position in which a solid cleaning agent is supplied, Figure 2(b) shows the cleaning device in an operating position in which water is supplied and the cleaning agent is dissolved therein to form a cleaning solution, Figure 2(c) shows the cleaning device in the operating position in which the cleaning solution is discharged and Figure 2(d) the cleaning device is again in the basic position in which it is ready to receive the solid cleaning agent; Fig. 3:a schematic representation of a second embodiment of a cleaning device according to the invention in a basic position.

[0040] The Figure 1The cleaning device shown comprises a first chamber 4 with a first piston 6 movably arranged therein, and a second chamber 3 with a second piston 5 movably arranged therein. The first chamber 4 and the second chamber 3 are hollow cylindrical and each have a cylindrical wall. The first chamber 4 extends vertically from an open upper end to a lower end, which is funnel-shaped and opens into a discharge line 13 connected to the first chamber 4. The first piston 6 can be inserted into the first chamber 4 through the upper end which is open. The second chamber 3 is arranged above the first chamber 4 and also extends between an upper end and a lower end, wherein the lower end has a base with a central opening. At the upper end of the second chamber 3, a water inlet nozzle is arranged, to which a water line 1 is connected.The water line 1 is part of a fluid line system of the cleaning device, which comprises 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 at a temperature of at least 40°C and in particular in the range between 60°C and 100°C. A shut-off valve 10 is arranged in the water line 1 and serves to open and close the water line 1. Instead of a shut-off valve, or in addition thereto, a control valve and / or a pressure reducer can also be arranged in the water line 1.

[0041] In the area of ​​the upper end of the second chamber 3, a stop 21 is arranged, which can be formed, for example, by an annular flange projecting from the wall of the second chamber 3 into the chamber interior. The second piston 5, which is movably arranged in the second chamber 3, can move in the second chamber 3 between a basic position a and an operating position b, wherein an upper side of the second piston 5 in the Figure 1 shown basic position a rests against the stop 21 and a bottom side of the second piston 5 in the position shown in Figure 2b shown operating position b rests on the bottom of the second chamber 3 or is at least close to the bottom.

[0042] As from Figure 1As can be seen, the second chamber 3 has a larger cross-section and, in particular, a larger diameter than the first chamber 4. Accordingly, the second piston 5 also has a larger cross-section and, in particular, a larger diameter than the first piston 6.

[0043] The first piston 6 and the second piston 5 are each cylindrical or disc-shaped and connected to one another via a connecting line 18, wherein the connecting line 18 extends through both the first piston 6 and the second piston 5 and runs through the central opening in the bottom of the second chamber 3. The connecting line 18 thus establishes a fluid connection between the first chamber 4 and the second chamber 3. A nozzle 11 is preferably arranged in the connecting line 18.

[0044] In the second chamber 3, a spring element 7 is arranged, for example a spiral spring, which extends between the underside of the second piston 5 and the bottom of the second chamber 3. The spring element 7 is arranged in particular around the connecting line 18, as can be seen from Figure 1 The bottom of the second chamber forms a support 19 against which the spring element 7 rests. The spring element 7 preloads the second piston 5 in the second chamber 3 in its (upper) basic position a. Accordingly, the first piston 6, connected to the second piston 5 via the connecting line 18, is also in an (upper) basic position a, in which the first piston 6 is pulled out of the first chamber 4.

[0045] The first piston 6 and the second piston 5 each have at least one circumferential sealing ring 17, 17' on their outer circumference, the sealing ring 17 of the first piston 6 resting on the inside of the wall of the first chamber 4 and the sealing ring 17' of the second piston 5 resting on the inside of the wall of the second chamber 3 when the second piston 5 is moved in the second chamber 3 from its (upper) basic position a into its (lower) operating position b and the first piston 6 simultaneously moves into the first chamber 4.

[0046] The first piston 6 and 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 basic position a by the spring element 7 and can be moved from the basic position a into an operating position b by introducing an external force.

[0047] A cleaning agent inlet 12 is arranged in the region of the upper end of the first chamber 4. The cleaning agent inlet 12 comprises a lateral opening (not shown in the drawing here) in the wall of the first chamber 4, through which opening a solid cleaning agent 8, for example in tablet or spherical form, can be introduced into the first chamber 4. In order to dose the solid cleaning agent 8 in a predetermined amount into the first chamber 4, the cleaning agent inlet 12 is connected to a cleaning agent dispenser or a dosing device which doses the solid cleaning agent 8 through the cleaning agent inlet 12 into the first chamber 4. The solid cleaning agent 8 is preferably in the form of tablets or spheres, which are dosed individually into the first chamber 4 by means of the cleaning agent dispenser or the dosing device.In this case, several tablets or balls of the solid cleaning agent 8 can also be introduced into the first chamber 4 via the cleaning agent inlet 12, as in . Figure 1 indicated by the two cleaning agent balls 8, which are located at the lower, funnel-shaped end of the first chamber 4.

[0048] In the area of ​​the upper end, a compressed gas line 2 opens into the second chamber 3. The compressed gas line 2 contains a check valve 9 and is connected upstream of the check valve 9 to a compressed gas source 16, which provides a compressed gas, for example, compressed air. Instead of compressed air, other food-compatible gases can also be provided under pressure by the compressed gas source 16. For this purpose, compressed nitrogen gas or compressed carbon dioxide, for example, can also be used instead of compressed air. The compressed gas source 16 can, for example, be formed by a compressor that draws in ambient air and compresses it to a predetermined pressure.

[0049] The drain line 13 connected to the lower end of the second chamber 4 is coupled to a beverage preparation machine 15 and, in particular, to a fluid line system of the beverage preparation machine 15 in order to direct an aqueous cleaning agent solution, which is generated in the cleaning device, into the fluid line system of the beverage preparation machine 15 and, in particular, into the components of the beverage preparation machine 15 that come into contact with the beverages prepared therein and / or the beverage ingredients used therefor. At least one valve is arranged in the drain line 13 to open and close the drain line 13. The drain line 13 preferably contains a control valve 14 having an adjustable flow cross-section.

[0050] The Figure 1The cleaning device shown is expediently arranged in a housing of the beverage preparation machine 15. The cleaning device is preferably inserted as an exchangeable module in the housing of the beverage preparation machine 15. The water connection 20 and the compressed gas source 16 are preferably components of the beverage preparation machine 15, which, on the one hand, can be used in the beverage preparation machine to provide hot water and compressed gas during the production of beverages and, on the other hand, supply the cleaning device with warm water via the water line 1 and with a compressed gas via the compressed gas line 2. The water connection 20 can, in particular, be formed by a boiler or a continuous-flow heater of the beverage preparation machine 15.

[0051] To control the cleaning device, a control device is provided, which in particular controls the valves 10 and 14 in the water line 1 and the drain line 13, as well as the supply of a compressed gas from the compressed gas source 16 through the compressed gas line 2 and the introduction of solid cleaning agent 8 through the cleaning agent inlet 12 into the first chamber 4. The control device can expediently be a component of the control device of the beverage preparation machine 15, which is configured such that a cleaning process is initiated by the cleaning device after or at specific times or events that depend in particular on the production of beverages in the beverage preparation machine 15.

[0052] In Figure 2 are individual phases of a cleaning process that is carried out with the cleaning device of Figure 1 can be carried out, represented by different positions of the cleaning device, whereby the Figure 2 The phases shown in the cleaning process are carried out one after the other in order to convey a cleaning agent solution produced in the cleaning device to a beverage preparation machine in a continuous operation or in a batch operation.

[0053] In Figure 2a The cleaning device is shown in its basic position a, which corresponds to the representation of Figure 1 To initiate a cleaning process, with the compressed gas source 16 or the compressed gas line 2 closed and the valves 10 and 14 closed, a predetermined amount of cleaning agent 8, for example a certain number of cleaning agent tablets or balls, is first introduced into the first chamber 4 through the cleaning agent inlet 12. Thereafter, as in Figure 2bshown, the valve 10 in the water pipe 1 is opened. Furthermore, the control valve 14 in the drain pipe 13 is at least partially opened and in particular set to a predetermined flow cross-section. As a result, preferably warm water, for example with a temperature of 40 °C to 80 °C, and with a predetermined pressure, which is preferably more than 3 bar and in particular between 4 bar and 10 bar and depends specifically on the water pressure provided by the public water supply, flows from the water pipe 1 into the upper area of ​​the second chamber 3. The water pressure can, if necessary, be set to a specific value by a pressure control valve or a pressure reducer in the water pipe 1. Due to the pressure of the inflowing water acting on the upper end face of the second piston 5, the second piston 5 in the second chamber 3 is moved from its Figure 2a shown basic position a into the Figure 2bshown operating position b, in which the second piston 5 is located in the second chamber 3 near the bottom. Since the second piston 5 is coupled to the first piston 6 via the connecting line 18, the first piston 6 also moves from its Figure 2a shown basic position a, in which the first piston 6 is pulled out of the first chamber 4, into the position shown in Figure 2b shown operating position b, in which the first piston 6 is located at a certain height within the first chamber 4. The first piston 6 is arranged above the balls of the cleaning agent 8 located in the first chamber 4, as in Figure 2b shown. By the movement of the first piston 6 into its Figure 2bIn the operating position b shown, the cleaning agent access 12 and in particular the opening in the wall of the first chamber 4 is closed, so that no cleaning agent can reach an area below the first piston 6 in the first chamber 4.

[0054] The water flowing via the water line 1 into the second chamber 3 flows through the nozzle 11 in the connecting line 18 into the first chamber 4, which is fluidly connected 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 counterforce exerted on the first piston 6 by the water introduced into the first chamber 4 is smaller than the force exerted by the water pressure on the second piston 5, whereby the first piston 6 and the second piston 5 are each held in their operating position b as long as water is introduced via the water line 1. The nozzle 11 ensures a sufficiently high pressure upstream of the nozzle 11 to hold the piston unit in its operating position b.

[0055] As water flows into the first chamber 4 in the area below the first piston 6, the balls of cleaning agent 8 located in the first chamber 4 are dissolved into an aqueous cleaning solution. The concentration of cleaning agent 8 in the cleaning solution is determined by the amount of cleaning agent in the first chamber 4 and the volume flow of the water flowing through, which is determined by the set flow cross-section in the drain line 13.

[0056] The closed cleaning agent access 12 ensures that no further cleaning agent can be added to the first chamber 4 during the dissolution of the cleaning agent 8 into the cleaning agent solution.

[0057] Thus, with a predetermined flow cross-section in the drain line 13 and a specific amount of cleaning agent 8 in the first chamber 4, a specific cleaning agent concentration is established in the cleaning agent solution, which continuously flows into the drain line 13 and is thereby conveyed to the beverage preparation machine 15, in particular into the fluid line system of the beverage preparation machine 15. There, in particular, the components of the beverage preparation machine 15 that come into contact with the beverage and / or the beverage ingredients (such as coffee powder, milk, or milk foam) during the production of beverages are cleaned by the aqueous cleaning agent solution.

[0058] The temperature and pressure of the water introduced into the first chamber 4 ensure complete dissolution of the solid cleaning agent 8 in the cleaning solution. After transferring a sufficient amount of the aqueous cleaning solution for the cleaning process, the valve 10 of the water line 1 is closed, thereby stopping the water supply. Afterward, as shown in Figure 2c As shown, a compressed gas, in particular compressed air, is introduced via the compressed gas line 2 into the upper region of the second chamber 3, wherein the pressure of the compressed gas is preferably more than 1 bar and in particular between 1.5 bar and 3 bar. Due to the pressure of the introduced compressed gas, which flows from the second chamber 3 via the connecting line 18 into the first chamber 4, any residual amount of cleaning agent solution still present in the first chamber 4 is pressed into the drain line 13.

[0059] Instead of the continuous operation described above, the cleaning device can also be operated in batch mode, in which a specific dose of a cleaning agent solution with a specific concentration of the cleaning agent is first generated in the first chamber and then fed to the beverage preparation machine 15 via the drain line 13. In this batch mode, the volume of a dose of the cleaning agent solution generated is determined by the position of the first piston 6 in the first clamp 4 in its operating position b, because this position determines the volume of the first chamber 4 below the first piston 6, in which the solid cleaning agent 8 is located. The position of the first piston 6 in the first chamber 4 in its operating position can be adjusted with the drain line 13 closed by the pressure of the water introduced via the water line 1.Thus, the volume of the dose of the aqueous cleaning agent solution in the first chamber 4 can be varied by the water pressure. When the solid cleaning agent 8 dissolves, a specific concentration of the cleaning agent 8 in the aqueous cleaning agent solution results, which is determined by the predetermined amount of the cleaning agent 8 in the first chamber 4 and the volume of the first chamber 4 below the first piston 6.

[0060] After the cleaning agent 8 has dissolved in the cleaning solution, the generated dose of cleaning solution is supplied to the beverage preparation machine 15 via the drain line 13. This is achieved by opening the drain line 13, in particular the valve 14, with the valve 10 in the water line 1 closed, and introducing a pressurized gas into the first chamber 4 via the pressurized gas line 2. The dose of the aqueous cleaning solution has a specific concentration of the cleaning agent in the cleaning solution, whereby the concentration can be varied by the amount of cleaning agent 8 supplied to the first chamber 4 and the water pressure during the preparation of the cleaning solution. A control valve 14 arranged in the drain line 13 advantageously enables the setting of a specific volume flow of the aqueous cleaning solution from the first chamber 4 into the drain line 13 when draining the cleaning solution.

[0061] After transferring the cleaning solution from the first chamber 4 into the fluid line system of the beverage preparation machine 15 in continuous operation or in batch operation of the cleaning device, the cleaning process is completed and the cleaning device is returned to its home 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 with a valve). As a result, the piston unit, which comprises the first piston 6, the second piston 5 and the connecting line 18, moves back to its home position a, which is Figure 2dis shown. In this case, the piston unit is automatically brought into the basic position a due to the restoring force of the spring element 7, in which the second piston 5 rests against the stop 21 of the second chamber 3 and the first piston 6 is pulled out of the first chamber 4 at least so far that the first piston 6 is located above the cleaning agent inlet 12 and in particular above the opening in the wall of the first chamber 4, as in Figure 2d shown. In this basic position a of the cleaning device, the first chamber 4 is again available to hold a predetermined amount of the solid cleaning agent 8 and in particular to hold a certain number of balls or tablets of the cleaning agent 8, and the cleaning device can be used for a subsequent cleaning process.

[0062] In Fig. 3A second embodiment of a cleaning device according to the invention is shown in the basic position. This embodiment corresponds to the cleaning device of Fig. 1 except for the arrangement of the pressure gas line 2, which in the embodiment of the Fig. 3 not into the second chamber 3 but into the water line 1. In the water line 1, a further check valve 9' is arranged to prevent compressed gas from flowing from the compressed gas line 2 towards the water connection 20. In this embodiment, the compressed gas from the compressed gas source 16 is guided via the compressed gas line 2 into the water line 1 in order to press the cleaning agent solution located in the first chamber 4 into the drain 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 Fig. 3is distinguished from the design of the Fig. 1 by a simpler structure of the second chamber 3.

[0063] The cleaning device according to the invention enables rapid and complete dissolution of the solid cleaning agent in the aqueous cleaning agent solution, in particular due to the pressure and temperature of the water supplied via the water line 1. Furthermore, precise dosing of a quantity of the solid cleaning agent 8 and maintenance of a specific concentration of the cleaning agent in the aqueous cleaning agent solution are ensured, wherein the precise cleaning agent concentration can be controlled in particular via the water pressure of the water supplied via the water line 1. The cleaning device has a simple and compact design and does not require any motor control to transfer the cleaning device from its home position a to its operating position b and back.

Claims

1. Cleaning device for a beverage preparation machine (15), in particular for a coffee machine, comprising a first chamber (4) for receiving a cleaning agent (8) and a liquid pipe system (1, 13) coupled to the first chamber (4) and having a water pipe (1) for supplying water which can be connected to a water connection (20), and a discharge line (13) which is connected to the first chamber (4) and which can be connected to the beverage preparation machine (15), wherein the first chamber (4) has a cleaning agent access (12) and a first piston (6) can be inserted into the first chamber (4) and moved between a base position (a), in which the first piston (6) is pulled out of the first chamber (4), and an operating position (b), in which the first piston (6) is located in the first chamber (4), characterised in that the cleaning agent access (12) has an opening in the first chamber (4) and is connected to a cleaning agent dispenser or a dosing device, which doses the cleaning agent through the cleaning agent access (12) into the first chamber (4), wherein the first piston (6) in its operating position (b) is located in the first chamber (4) to such an extent that the cleaning agent access (12) is blocked.

2. Cleaning device according to claim 1, characterised in that the first piston (6) is part of a piston unit (5, 6, 18) which comprises the first piston (6), a second piston (5) arranged movably in a second chamber (3) and a connecting line (18) arranged between the first piston (6) and the second piston (5), wherein the second chamber (3) is arranged upstream of the first chamber (4) and is in fluid-conducting connection with the first chamber (4) via the connecting line (18) and a movement of the second piston (5) is transmitted to the first piston (6) via the connecting line (18), wherein a nozzle (11) is preferably arranged in the connecting line (18).

3. Cleaning device according to claim 2, characterised in that the piston unit (5, 6, 18) comprises a spring element (7) located in particular between the first piston (6) and the second piston (5) and in particular around the connecting line (18), and the spring element (7) is preferably supported on a support (19) in the second chamber (3) and extends in particular between the support (19) and the second piston (5), the support (19) preferably is arranged in an end region of the second chamber (3), in particular on a base of the second chamber (3), wherein in an unloaded state, the spring element (7) exerts a preload on the first piston (6), which holds the first piston (6) in its base position (a), and / or the first piston (6), when water is supplied through the water pipe (1), can be moved from its base position (a) to its operating position (b) against a preload generated by the spring element (7).

4. Cleaning device according to any one of claims 2 or 3, characterised in that the second chamber (3) has a stop (21), which is arranged in particular in the region of the upper end of the second chamber (3), wherein the second piston (5) in an unloaded base position (a) is contacting the stop (21).

5. Cleaning device according to any one of claims 2 to 4, characterised in that the second chamber (3) has a larger cross-section, and in particular a larger diameter, than the first chamber (4) and / or that the second piston (5) has a larger cross-section, and in particular a larger diameter, than the first piston (6).

6. Cleaning device according to any one of the preceding claims, characterised in that the cleaning agent access (12) is in an upper region or at an upper end of the first chamber (4), wherein the first piston (6) in its operating position (b) is located in the first chamber (4) to such an extent that access from the opening into the first chamber (4) is blocked.

7. Cleaning device according to any one of claims 2 to 6, characterised in that the second chamber (3) is connected to a compressed gas line (2), wherein the compressed gas line (2) can be coupled to a compressed gas source (16) and preferably opens into the second chamber (3) or into the water pipe (1) in an upper section or at an upper side.

8. Cleaning device according to any one of the preceding claims, characterised in that a shut-off valve (10) and / or a control valve, in particular a pressure control valve, and / or a pressure reducer is arranged in the water pipe (1) and / or that a shut-off valve and / or a control valve (14) is arranged in the discharge line (13).

9. Beverage preparation machine (15), in particular coffee machine and / or machine for preparing a powdered beverage, with a cleaning device according to any one of the preceding claims, wherein the beverage preparation machine (15) preferably comprises a brewing device for brewing of a hot beverage and / or a device for heating and / or frothing of milk, and the cleaning device is coupled in particular to the brewing device and / or to the device for heating and / or frothing of milk.

10. Method for cleaning a beverage preparation machine (15) having a cleaning device comprising a first chamber (4) and a first piston (6) insertable therein as well as a cleaning agent access (12) which has an opening in a wall of the first chamber (4) and is connected to a cleaning agent dispenser or a dosing device, wherein by means of the cleaning agent dispenser or the dosing device a defined amount of a preferably solid cleaning agent (8) is dosed through the cleaning agent access (12) into the first chamber (4) and then water is fed into the first chamber (4) via a water pipe (1) that can be connected to a water connection (20),while the first piston (6) is inserted in an operating position in the first chamber (4), whereby the cleaning agent (8) is dissolved or / and mixed in a cleaning agent solution, and the cleaning agent solution is fed to the beverage preparation machine (15) via a discharge line (13) connected to the first chamber (4), wherein the first piston (6) is movable between a base position (a), in which the first piston (6) is pulled out of the first chamber (4), and an operating position (b), in which the first piston (6) is inside the first chamber (4), and the first piston (6) is located in its operating position (b) in the first chamber (4) to such an extent that the cleaning agent access (12) is blocked.

11. Method according to claim 10, wherein the water fed into the first chamber (4) has a temperature of at least 40°C, preferably more than 60°C and in particular from 60°C to 100°C.

12. Method according to any one of claims 10 or 11, characterised in that the first chamber (4) is fluidly coupled to a second chamber (3) and the water pipe (1) is connected to the second chamber (3) to supply water into the second chamber (3) and the first chamber (4), wherein, after the dosing of the cleaning agent into the first chamber (4), the first piston (6) is introduced into the first chamber (4) in its operating position and after introduction of the first piston (6) into the first chamber (4) the water is introduced into the first chamber (4) through a connecting line (18), with the connecting line (18) preferably running through the first piston (6).

13. Method according to claim 12, characterised in that the first piston (6) is coupled to a second piston (5) via the connecting line (18) and the second piston (5) is arranged movably in the second chamber (3), wherein the first chamber (4) is connected via the connecting line (18) to the second chamber (3) in a fluid-conducting manner, and the water pipe (1) is connected to the second chamber (3) and, when water is supplied through the water pipe (1), the first piston (6) is pressed into the first chamber (4) by a pressure generated by the introduced water, wherein the pressure generated by the introduced water is applied to the second piston (5) and is transferred from this to the first piston (6).

14. Method according to any one of claims 10 to 13, characterised in that, after the cleaning solution has been produced by dissolving or mixing the cleaning agent (8) in the water that has been supplied to the first chamber (4), the supply of water is stopped and then the cleaning agent solution is removed from the first chamber (4) and pressed into the discharge line (13) by introducing a pressurised gas into the first chamber (4), and that preferably the introduction of the pressurised gas into the first chamber (4) is stopped when the cleaning solution has been completely transferred into the discharge line (13), whereby the first piston (6) preferably moves out of the first chamber (4) into its base position (a) automatically due to a restoring force after the pressurised gas has been introduced.

15. Method according to any one of claims 10 to 14, characterised in that a shut-off valve and / or a control valve (14) for opening and closing the discharge line (13) is arranged in the discharge line (13), whereby either when the discharge line (13) is at least partially open or when the discharge line (13) is closed, water is passed through the first chamber (4), whereby the cleaning agent (8) is dissolved or mixed into a cleaning solution and the cleaning solution is discharged to the beverage preparation machine (15) through the at least partially opened discharge line (13) or after opening the initially closed discharge line (13).