WO2024120673A1 - Device for automatic rinse and clean of milk froth system - Google Patents

Abstract

Liquid food dispensing system with at least one supply of milk (6), at least one element (10) for the treatment of milk and at least one outlet head (13) for dispensing the liquid food, wherein the system further comprises at least one cleaning container (14) for at least one cleaning liquid, with at least one cleaning line (3a) connecting the cleaning container (14) with a line (6a) connecting the supply of milk (6) with said element (10) for the treatment of milk, at least one supply of water (1), wherein the outlet head (13) can be connected to the cleaning container (14) with at least one circulation line (14c) allowing for circulation of cleaning liquid and/or water in a circulation path through the cleaning container (14), by way of the cleaning line (3a), through the element (10) for the treatment of milk, the outlet head (13) and back to the cleaning container (14).

Description

TITLE

DEVICE FOR AUTOMATIC RINSE AND CLEAN OF MILK FROTH SYSTEM

TECHNICAL FIELD

The present invention relates to a device for the production of milk froth with self-cleaning functionality as well as to methods for operating such devices.

PRIOR ART

Devices for frothing liquids, such as milk, are well known in the art, for example from EP-A- 485350, which discloses a device for homogenizing, mixing and emulsifying liquid products, such as milk. The device comprises a container and a pump connected by an inlet conduit. The device additionally comprises an air inlet valve that emanates in the inlet conduit. The pump is connected to an outlet conduit that emanates in a jet breaker spout. The outlet conduit is provided with a heating element. In use, an amount of liquid from the container and a predetermined amount of air from the air inlet are provided to form an air/liquid- mixture that is supplied to the pump. In the pump the air/liquid- mixture is frothed by mechanical whipping. When required by the user, the frothed liquid is heated using the heating element. To clean the known device, partial disassembly of the known device is necessary.

WO-A-2017046230 discloses an apparatus for dispensing liquid foodstuffs, in particular milk products, with an integrated cleaning system which is straightforward and reliable to handle. Provision is made for a foodstuff-supply line to be provided with a connection, on which can be fitted an intake line which leads to a storage tank containing the liquid foodstuff, and for a connecting element to be provided, it being possible for said connecting element, when the intake line has been removed, to be fitted onto the connection in order for the foodstuffsupply line to be connected fluidly to the integrated cleaning system.

EP-A-3345518 proposes a method for cleaning a milk system with dispensing device, which is assigned to a beverage maker, comprising a control unit and a cleaning module. The method comprises the following steps, replacement of a milk container of the milk system by the cleaning module, comprising at least two zones wherein in a first zone and in a second zone cleaning fluid and in a chamber a cleaning agent is filled. Connecting the first zone and the second zone with docking stations of the milk system for suction of cleaning fluid, conveying the cleaning fluid through the milk system and at least partially returning the cleaning fluid to the cleaning module rinsing the milk system with cleaning fluid, wherein cleaning fluid from the first zone and / or from the second zone of the cleaning module is conveyed and discharged by the milk system. Circulatory flushing of the milk system, wherein cleaning fluid is taken from the second zone, heated by means of a heating device and returned to the chamber, it entering the second zone via the fluid-conducting connection. Ending the circuit flushing, with cleaning fluid being discharged and a valve device of the second zone closing when the level of cleaning fluid in the second zone has fallen below a certain level; and final rinsing of the milk system with cleaning fluid from the first zone.

WO-A-2021074038 relates to a cooling device with a coolable storage room for storing several storage containers with liquid foods, which are to be provided at a beverage dispensing device connected to the cooling device for dispensing, two or more receiving bays are provided, which are used to each accommodate a pump module with which liquid food of a type of food assigned to the pump module in question can be conveyed to a beverage dispensing device connected to the cooling device.

US-A-2019069713 discloses an assembly for frothing a fluid having an air channel with a controllable air valve and having a fluid channel with an air inlet emanation point in which the air channel emanates, a pump, a fluid restriction, a heater, and a valve assembly having a first state in which fluid is channeled to a fluid outlet of the fluid channel and a second state in which the fluid is diverted from the fluid channel to a second fluid outlet. A water supply channel is connected to the fluid channel. The assembly also includes a cleaning reservoir and a return channel that is connected to the second fluid outlet of the valve assembly and that emanates in the cleaning reservoir. An electronic controller assembly is configured to control at least the pump, the heater, and the valve assembly, and to operate the assembly in a production mode and a cleaning mode.

US-A-2014116475 relates to a cleaning system for coffee machines and similar devices, in the cleaning circuit of which a cleaning key having a storage chamber is installed for receiving appropriately configured cleaning tablets. The cleaning key can be turned in a sleeve-like housing into two operating positions at defined angles of rotation, wherein in one operating position the storage chamber is fixed in the housing, whilst in the other operating position the storage chamber is released and can be removed from the housing to be filled or refilled with suitably packaged cleaning tablets.

US-A-2005233043 discloses methods i.e. a device for producing of milk foam or warm milk drinks, whereby milk is suctioned from a container by means of a pump and conveyed to an outlet. The milk is routed through a continuous-flow heater during suctioning and heated, whereafter the same is conveyed to an outlet via a throttle point. In this way an extremely digestible milk foam can be produced in a simple way when air or a gas is added to the milk. DE-A-102012200280 discloses a vending machine which has a fresh water tank, a pipe leading from the fresh water tank to an output unit, and a reservoir, particularly a milk container. An outlet end of a supply pipe is connected with the output unit and the inlet end is connected with the reservoir. The Venturi geometry is provided in the output unit, by which a suction of liquid from the reservoir by low pressure takes place. A branch line is provided, which branches off between the fresh water tank and the output unit from the pipe. An independent claim is included for a method for cleaning a supply pipe, particularly a milk supply pipe and an output unit, particularly a milk frothing unit of a vending machine.

DE-A-102020119975 discloses a method for cleaning a device for adding beverage additives, in particular flavorings, to a beverage machine, in particular a coffee machine, which is characterized by at least the following method steps: a) providing the beverage machine, in particular a coffee machine, wherein the Beverage machine has at least one water pump and a boiler connected to the water pump via a line and a beverage dispenser, as well as a device for adding beverage additives to each drinks prepared with the beverage machine, the device for adding beverage additives having a housing into which a plurality of beverage additive containers can be adjusted, each of which is filled with a beverage additive, each beverage additive container is connected to a beverage dispenser via a respective hose and a respective pump directly or via further flow-through elements; b) removing the beverage additional container, c) inserting a container, in particular a container that is open at the top, in place of the beverage additive containers, so that the free ends of the hoses protrude into the container; d) fill the container with hot water from the boiler via the open valve and the line until the hoses are completely or partially in the water immerse in the container ; and e) put the pumps into operation and convey the hot water from the container into and through the beverage dispenser so that the hot water emerges from it.

SUMMARY OF THE INVENTION

For hygienic reasons, milk-cleaning must carried out regularly per day or several times a day in machines handling milk. Depending on the system, this process requires manual steps until the cleaning process starts. Furthermore, the handling of aggressive cleaning solutions is not without problems and incorrect manipulations often occur. Especially in the vending area, the systems are often not cleaned every day and the operating only happens 1-2 times a week.

The present invention addresses this gap and realizes a fully automatic cleaning for a liquid food dispensing system with at least one supply of milk without manual intervention.

A multifunction outlet head allows operating the system with at least four possible process modes: (1) In a dispense mode for dispensing the liquid food product;

(2) In a drain mode for redirecting the content in the lines to waste;

(3) In a circulation mode towards a cleaning container to clean the system in a circular mode;

(4) In a closed mode to close the system to avoid contact by hand especially when using the system with cold drinks to avoid any recontamination.

A main further advantage of the system is a safe operation cleaning compared to the other systems, as there is no restrictor/nozzle in the hydraulic. There is no risk of any blockage by milk residue.

More generally speaking, the present invention relates to a liquid food dispensing system (liquid food meaning a liquid suitable and adapted to be consumed by a human) with at least one supply of milk (to be part of or to constitute the liquid food), at least one element for the treatment of milk and at least one outlet head for dispensing the liquid food.

According to the invention, the system further comprises: at least one cleaning container for at least one cleaning liquid, with at least one cleaning line connecting the cleaning container with a line connecting the supply of milk with said element for the treatment of milk, at least one supply of water.

According to the invention, the outlet head can be connected to the cleaning container with at least one circulation line allowing for circulation of cleaning liquid and/or water in a circulation path, wherein the circulation takes place through the cleaning container, by way of the cleaning line, through the element for the treatment of milk, through the outlet head and back to the cleaning container.

Contrary to what is disclosed in the prior art, e.g. in US-A-2019069713, which does not disclose an outlet head as described above, but only a three way valve, which is connected to an outlet pipe, which outlet pipe 20 cannot be cleaned, however the cleaning is interpreted according to this document. Further the document does not disclose circulation during cleaning.

The advantages of the proposed approach compared with what is what is disclosed in the prior art correspondingly are the allowing of full circulation cleaning directly including the very outlet head of the liquid, i.e. involving the outlet head and thereby allowing for avoiding an outlet pipe which would have to be cleaned separately. Also the outlet head for cleaning according to the invention does not have to be disassembled but is automatically cleaned. According to a first preferred embodiment, the outlet head is provided with means to switch at least between a dispense mode, in which liquid food is dispensed, and a circulation mode, in which the output of a line from the element for the treatment of milk is redirected to said circulation line.

The outlet head can further be provided with means to switch in addition to a drain mode, in which the output of said line from the element for the treatment of milk is redirected to waste.

Preferably or alternatively it is further provided with means to switch to a closed mode, in which said line from the element for the treatment of milk is blocked, the circulation line is blocked and the line redirecting to waste is blocked.

The outlet head preferably takes the form of a multifunction outlet head which comprises at least two elements, which are mechanically movable relative to each other to switch between dispense mode, circulation mode, if present drain mode and if present closed mode, wherein preferably the at least two elements take the form of at least one plate or element which can be shifted and/or rotated relative to another plate or element.

Alternatively, the outlet head can be provided with means to allow for manual attachment or automatic engagement of an outlet head cup, which closes the outlet opening of the outlet head and provides for a return cavity, such that in circulation mode, output from said line from the element for the treatment of milk is redirected to said circulation line by way of said return cavity.

In this case, preferably the outlet opening of the outlet head is provided with a circumferential inner skirt and a circumferential outer skirt with a contiguous circumferential interspace between these skirts, and this contiguous circumferential interspace is connected to the circulation line.

According to yet another preferred embodiment the outlet head cup is provided with at least one magnetic element allowing for self-engaging attachment of the outlet head cup, to the, preferably metallic, outlet head.

In the tip portion, the outlet head can be provided with a widening terminal outlet area, and at the transition from said line from the element for the treatment of milk to this widening terminal outlet area, there can be provided at least one, preferably central, flow guiding element.

According to yet another preferred embodiment, the system further comprises a cleaner container, which is connected to the circle, preferably by way of a pump for introducing cleaner into the cleaning container. The cleaner container may contain a cleaning liquid, but may also contain a cleaner powder or granules, or even tablets of cleaning agent.

The system may further comprise at least two different milk containers or at least one milk container and at least one further liquid food container (e.g. flavorings or the like), and wherein said cleaning line connects the supplies of milk an/or the supply of milk and at least one further liquid food container by way of a milk cleaning manifold, with at least two inlets for liquid food, at least two outlets for liquid food, at least one inlet for the cleaning line, and an inlet for a water line, the cleaning and water lines being fluidly connected to each of the liquid food lines. Preferably at the inlet side for the liquid food of such a milk cleaning manifold elements for preventing backflow are provided.

Preferably, the proposed system is a system for providing milk froth, either exclusively or in combination with providing liquid coffee or other liquids such as liquid chocolate and combinations of milk froth and liquid coffee.

Preferably the element for the treatment of milk comprises at least one pump (e.g. an impeller pump) and at least one homogenizer.

In the circulation path there is further preferably provided at least one conductivity sensor for measuring the conductivity of circulating or stationary cleaning liquid to control the cleaning process.

In addition, the present invention relates to a method for operating a system as detailed above.

According to this method, for the cleaning of the system the outlet head is connected to the cleaning container and cleaning liquid is circulated through the cleaning container, by way of the cleaning line through the element for the treatment of milk, the outlet head and back to the cleaning container.

According to a preferred embodiment of the proposed method, before circulation, by way of the supply of water the circulating path is filled with water replacing milk in the circulating path while dispensing the milk in the circulating path to a waste container, and wherein while keeping the supply of water and stopping dispensing liquid in the circulating path to a waste container the circulation is established until a sufficient amount of cleaning liquid is circulating and contained in the cleaning container, followed by circulation and/or soaking and/or heating, preferably until a conductivity sensor detects appropriate conductivity values in the circulation liquid.

Circulation is preferably followed by further supply of water and accompanied or followed by emptying the circulating path to a waste container by corresponding automatic switching of a multifunction outlet head.

For the proposed method further preferably there is further provided a cleaner container, and wherein before circulation cleaner (liquid or powder or tablets) is introduced into the circulating path, preferably into the cleaning container from that cleaner container.

Preferably, the method comprises at least one soaking phase, in which the circulating path is filled with cleaning liquid above room temperature, typically at a temperature in the range of 50-80°C, and wherein in that soaking phase the cleaning liquid is not or only very slowly circulated.

Last but not least, the present invention relates to the use of a method as detailed above for cleaning of system for the generation of milk froth.

Further embodiments of the invention are laid down in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings, Fig. 1 shows a schematic for a semi-automatic cleaning process;

Fig. 2 shows a schematic for a fully automatic cleaning process;

Fig. 3 shows a detail of a fridge configuration;

Fig. 4 shows a milk cleaning manifold in the fridge, wherein a) shows a perspective view in transparent mode and b) a front view;

Fig. 5 shows the function and 3 positions of the movable outlet head, wherein a) shows the position with the open outlet, b) the position to drain, c) the position of recirculation to the cleaner container and d) the closed position;

Fig. 6 shows an outlet head with clean head cup in particular for a set-up according to Fig. 1 , wherein in a) an axial cut is shown, in b) a side view, in c) a perspective view from the top, wherein the outlet head and the uppermost portion of the clean head cup are cut axially as in a), and in d) a perspective view from the top.

DESCRIPTION OF PREFERRED EMBODIMENTS

Fig. 1-6 show different representations of a homogenizer or more generally speaking a device for the production of milk froth with different cleaning and rinse processes as well as elements thereof.

More specifically, Fig. 1 shows a schematic for an automatic cleaning process, Fig. 2 shows a schematic for a fully automatic cleaning process, Fig. 3 shows a detail of the fridge configuration, Fig. 4 shows a the milk cleaning manifold in the fridge, Fig. 5 shows the movable outlet head with 4 positions.

Fig. 1 shows a flow diagram a device, which can be operated for the production of milk froth in foam dispensing mode in a rinse-cleaning mode.

For the actual foam production, milk (including plant-based milk) can be provided from containers 6 to a milk inlet of an extractor system 10 from a cooling unit or fridge 5, in which several milk containers 6 (for example containing different types of milk or other liquids as cold brew coffee, chocolate, flavors) are provided.

To control the corresponding milk source, a manifold valve block 4 is provided on top of or in the fridge, and a clean manifold block can be attached to that manifold 4 controlled by a flowmeter 17 and if needed, supplied by a separate water supply 1 or pump if the water supply is not under sufficient pressure. In that manifold 4, there is an inlet valve 2, as well as a clean return valve 3, to control the cleaning process as will be detailed further below. In the fridge there is provided a milk cleaning manifold 4a, the details of which will be provided further below.

Milk is then channeled to the actual extractor system 10 for the production of the milk froth, said extractor system 10 comprising a pump, for example an impeller pump 8, and a homogenizer 9. There is provided a conductivity sensor 7 upstream of the device 10, and the impeller pump is illustrated by reference numeral 8 schematically, and so is the homogenizer 9. An air pump typically provides for pressurized air, which is entering the system by way of a check valve.

The milk froth exiting the homogenizing device 10 in this case is heated downstream of that device in corresponding heating elements, which can be a thick film heating system 11 . Downstream thereof there is a three way valve 12 for cleaning purposes, and downstream of that valve there is the outlet head 13 for supply to a drink cup, or in case of the cleaning process to a clean head cup 13a. The clean head cup 13a allows recirculation of the output of the line 10a from the homogenizer to a cleaning container 14 via line 14c.

A possible and preferred outlet head for use in a process as illustrated in this figure is illustrated in Fig. 5 and will be detailed further below.

In a cleaning process, valve 12 can be used to redirect the output of the line 10a from the homogenizer by way of wastewater line 16 to a corresponding waste container 16a. Also for cleaning, a cleaning liquid container 14 is provided which is also connected to the manifold 4 via valve 3.

In cleaning mode, the liquid from the container 14 is channeled by way of the manifold 4 to pass through the extractor 10, in corresponding suitable and adapted combination with water supplied from source 1. Water exiting the extractor 10 is then channeled by way of valve 12 to the wastewater drain channel 16 and to a corresponding drainage container 16a or, if the outlet head 13 is to be cleaned, to the outlet head 13 to end up in outlet head cup 13a and being circulated to the cleaning container 14.

Cleaning of the outlet head 13 is either possible by way of the manifold valve block 4 and exit via line 16, but it is also directly possible as illustrated by the corresponding direct line 14c connecting the cleaning container 14 with the outlet head 13 or by way of circulation through the outlet head 13 via line 14c. The cleaning process can be fully automated without manual interaction. Especially for vending applications, this can be a big advantage. The cleaning can be done also easily during the day when there is a downtime. The cleaning especially with fresh milk and bigger drinks and milk volumes >40 liters (long run time with max temperature) tend to contaminate the tubes and heater and there is a risk of blockage.

Several cleaning processes can be applied during the day with activating the cleaning process as following:

Flash after each drink: (Process steps: to avoid any milk residues outside the fridge during rest period of the machine the flash already starts before the end of a drink cycle. The flash water rinses the entire milk channels and is flashed out via the 3/2 valve into the drain.

Flash in between two types of drink: This is a settable procedure especially when dairy and none-dairy products are applied. Based on tests there is more contamination when switch from non-dairy to a dairy product (as versa) longer rinse time is a settable parameter as well.

Cleaning procedure during the day settable by volume of used milk or at the end of a shift. A pre-warning of the cleaning process will be come up for internal cleaning and flash out in front into the drip tray. A cleaning process has to be done otherwise the system will be blocked. For high volume stores a multiple cleaning procedure can be most efficient. Normally these outlets have 3 rush hours times. In between there is enough time to clean and the cleaning process time of multiple cleaning can be reduced.

(Daily) Cleaning Process steps: (all time parameters settable)

Flash with cold or hot water approx. 8s

Fill cleaning container 14 with water approx. 360ml

Recirculate water in clean container 14 and heat up water till 65-75°C or 80°C. or

Fill up system with Cleaner from micro dosing pump or automated tablet dispenser (e.g. Volume in total system - Diameter inner 4mm, length approx. 2m- = 25ml) e.g. approx. 3-4 s via direct outlet and via drain.

Soak time 1 min.

Flash with hot or cold water out via outlet head and via drain 16 (3s each total 6s).

Repeat step previous steps 3 times.

Post rinse: Empty cleaner container 14 via outlet head 16

Flash with hot or cold water out via outlet head 16 (15s) and via drain (5s).

The cleaner can be provided by way of a cleaning liquid container having a controlled outlet (for example a tube connecting to the cleaning container 14) for dispensing cleaner liquid when needed into the cleaning container 14. Alternatively, an automated tablet dispenser can be provided sits directly above the cleaner container 14 as illustrated with 43. The cleaner container 43 can be a turret system where approx. 1 weeks' worth of tablets are stored, and if the scheme is to go through a cleaning process as described above once a day, this means 7-10 tablets in the respective storage disk of the tablet dispenser 43. Each time cleaning is required, the disc rotates of the tablet dispenser 43 and dispenses a cleaner tablet into the cleaning container 14.

The above-mentioned description relates to the daily cleaning procedure, i.e. the machine is programmed to go through this cleaning routine once a day, for example automatically at a time when there is no or little customers.

There can be provided in addition to that a more thorough weekly cleaning, during which typically the milk container 6 is removed and an (empty and clean) replacement cleaning container 14 (or the existing cleaning container is removed cleaned, and put back) is connected to the machine, if need be directly including a cleaning tablet or liquid cleaner and optionally even water. Also in such a weekly cleaning routine, if the system is provided with a liquid cleaner system and this is empty, the corresponding container is refilled or replaced by a full one, and if the system is provided with the above-mentioned automated tablets dispenser system for cleaning tablets, the process includes filling up that automated tablets dispenser with cleaner tablets, for example by way of replacement of a corresponding disc with cleaner tablets, or filling up of the disk in the system. The rest of the procedure is analogously the same as for daily cleaning. This also cleans the milk residues from the inside and outside of the intake hoses.

Fig. 2 shows a further modification of the cleaning scheme.

In this case there is an additional cleaner bottle 14b in parallel to the cleaning container 14, which allows, by way of a corresponding dosing pump 14a, to supply the required cleaning liquid to the cleaning container 14. Another solution is, if a cleaner tablet is preferred to add a tablet with a tablet dispenser.

Furthermore, and importantly, the outlet head is provided with a multifunction outlet head 13b allowing for automatic different operational modes for cyclic cleaning as will be detailed further below.

Fig. 3 shows a more detailed view of the situation in the fridge including the manifold valve block 4. As one can see, the line 2c coming from the water inlet valve 2 and the line 3a coming from the clean return valve 3 are directly channeled into the lines connecting the milk containers 6 with the manifold valve block 4 in a milk cleaning manifold 4a. Upstream of the entry into the corresponding line there can be provided a corresponding backflow prevention element 2b in each of these lines from the milk containers, these are also located in the milk cleaning manifold 4a. Also corresponding backflow prevention elements 2a can be provided upstream of the entry points of the respective lines 2c and 3a, again also these can be located in the milk cleaning manifold 4a.

It is noted that in this case separate lines with cleaning liquid are connected to separate lines from different milk containers 6, but, as illustrated in Fig. 1 and 2, it is also possible that the water line 2c and the cleaning liquid line 3a are connected to each of the lines 6a connecting the milk containers 6 with the manifold valve block 4, or it is also possible that the lines 2c and 3a are combined into one line before being connected to the lines 6a connecting the milk containers 6 with the manifold valve block 4.

Fig. 4 shows a preferred embodiment of a milk cleaning manifold block 4a. It is one suitable and adapted for four milk containers, so there are four entries for lines 6a from the corresponding milk containers 6 entering the milk cleaning manifold 4a. Right downstream of the corresponding respective entry opening into the milk cleaning manifold block, there is, for each line, provided a check valve 2b preventing backflow in the direction back into the corresponding milk container 6. For each of these lines then corresponding lines are branching off orthogonally to be connected to the lines 6b, which then individually enter the manifold valve 4.

Further there is provided a connecting line 24, running perpendicular to the entry lines 6a as well as to the output lines 6b, connected with each of the lines for the milk, and which connecting line 24 at one end is connected to line 3a for the circulating liquid, and at the opposite end are connected to line 2c to the water supply. At the outlet points for the milk to line 6b there can be provided further check valves to prevent back flow and also at the inlet positions there can be check valves 2a to prevent back flow to lines 2c and 3a.

This way an exceptionally compact construction is provided to provide for optimum cleaning possibilities in the direct vicinity of the milk containers in the fridge, which in turn can be controlled to cooperate optimally by way of the manifold valve block.

Fig. 5 shows the above-mentioned multifunction outlet head 13b in more detail.

The multifunction head 13b comprises an upper portion, which is guiding the line 14c to and from the cleaning container, the actual line 10a for the milk froth, as well as the line 16 to the wastewater container.

It furthermore comprises means to control the flow in the multifunction outlet head and out of the multifunction outlet head.

Specifically, there are provided an upper control plate 20 and a lower control plate 19. These control plates can be moved relative to each other (typically they can be rotated relative to each other) automatically by way of a motor and are provided with channels and openings such that at least four different operational modes can be implemented.

Specifically so in the form of a first position Xa, in which the multifunctional outlet head 13b is adapted to dispense milk froth by way of the outlet 21 for example into a cup or another container (dispense mode).

Furthermore, there is a position Xb, in which the outlet of the line 10a is connected with the wastewater drain line 16 by way of shortcut 22, so any fluid entering the multifunctional outlet head 13b by way of line 10a is guided to the wastewater container 16a (drain mode). Further, there is position Xc, in which there is a shortcut 23 between the line 10a and the line 14c to the cleaning container (circulation mode). This position allows circulation of cleaning fluid through the homogenizer, through the multifunction outlet head 13b and by way of the cleaning container 14 to the milk cleaning manifold 4a and to the manifold valve block 4.

Also, there is a closed position as illustrated as Xd, where all the lines 10a, 14c as well as 16 are blocked in the multifunction outlet head 13b (closed mode).

Several cleaning processes can be applied during the day or night with activating the cleaning process as following:

Flash after each drink: (Process steps: to avoid any milk residues outside the fridge during rest period of the machine the flash already starts before the end of a drink cycle. The flash water rinses the entire milk channels and is flashed out via the 3/2 valve into the drain.

A special control procedure with different components (ON/OFF) can be implemented to avoid any air bubbles at the end of the drink supply.

A further advantage is that the thick film heater 11 can be pre-heated with rinse water and the milk temperature heat up curve will be much faster.

Flash in between two types of drink: This is a settable procedure especially when dairy and none-dairy products are applied. Based on tests there is more contamination when switch from non-dairy to a dairy product (as versa) longer rinse time is a settable parameter as well.

Cleaning procedure during the day settable by volume of used milk or at the end of a shift. A pre-warning of the cleaning process will become up for internal cleaning and flash out in front into the drip tray. A cleaning process has to be done otherwise the system will be blocked. For high volume stores a multiple cleaning procedure can be most efficient. Normally these outlets have 3 rush hours times. In between there is enough time to clean and the cleaning process time of multiple cleaning can be reduced. Specific process steps: (time parameters settable):

Rinse/Flash:

Rinse with cold-water approx. 3-5 s depending on the hose length configuration.

Before the dispense cycle of the drink is finished, optionally the impeller pump 8 stops, optionally followed by the heater 11 being stopped, via mode Xa, the water valve 17 is opened and the entire line including extractor 10 and heater 11 is flushed with water just before the outlet head 13. At this moment either the valve 12 is opened or the multifunctional outlet head 13 is set to mode Xb and the final rinse water will go into the drain via line 16a.

Automated cleaning process:

Add a clean return cup 13a in order to clean the process in a cycle cleaning. This step can be automated by closing the outlet head and open the return hose towards the cleaning container in position Xc.

The advantage compared to the multifunction outlet head 13b is the compact design as in most cases there is limited space to integrate such a device.

However the big advantage with the multifunctional outlet 13b head is to completely empty the milk line. After the rinse cycle, the hose between valve 12 and the outlet head 13 is still contaminated with milk. Another disadvantage is also a dripping of milk after the dispense.

Fully-automated cleaning process:

Pre-Rinse:

Pump 8 and Heater 11 switched OFF;

Multifunctional head 13b in position drain Xb

Water valve 2 ON and rinse 8s

Fill cleaner container 14 and heat up:

Multifunctional head 13b in position cycle Xc

Water valve 2 ON (Volume approx. 360ml) approx.. 30s

Pump 8 ON Fill cleaner container with water

Liquid pump 14a or tablet dispenser ON (Dose approx. 40-50ml liquid cleaner) approx.. 30s

As soon as volume approx. 360ml reached:

Water valve 2 OFF and clean return valve 3 ON

Pump 8 ON, Speed 100% (10ml/s) and run cleaning cycle 90s

Heater 11 ON (control Temperature around 75-80°C) Recirculation and heat up water with Heater 11 ON (control Temperature around 75-80°C) (optional) Check with conductivity sensor 7 if cleaner liquid OK

Drain/Soak/Drain/Cyle

Pump 8 ON 100%

Heater 11 ON (control Temperature around 75-80°C)

Multifunctional head 13b in position drain Xb for 5 s and return to cycle Xc 5s

Soak time (Pump 8 and heater 11 OFF) 90s

Multifunctional head 13b in position drain Xb for 5 s and return to cycle Xc 5s

Pump 8 and Heater 11 ON and run cleaning cycle 40s

Drain/Soak/Drain/Cyle/drain

Multifunctional head 13b in position drain Xb for 5 s and return to cycle Xc 5s

Soak time (Pump 8 and heater 11 OFF) 90s

Multifunctional head 13b in position drain Xb for 5 s and return to cycle Xc 5s

Pump 8 and Heater 11 ON and run cleaning cycle 40s

Multifunctional head 13b in position drain Xb

Empty the cleaning container (remains approx. 320ml in Container) 32s

Post rinse

Clean return valve 3 and heater 11 OFF

Water valve 2 ON and rinse towards cleaning container 14 10s

Pump 8 and Heater 11 OFF

Clean return valve 3 ON and water valve 2 OFF

Pump 8 ON and empty remaining water in 14 by emptying via line 16a (Xb) 10s

Pump 8 OFF

Multifunctional head 13b remains in position drain Xb

Clean return valve 3 OFF and water valve 2 ON

Post rinse with cold water 30s

Check with conductivity sensor 7 the water value if OK

Total cleaning cycle 520s

(approx. 9 min)

The daily cleaning process can be done without decoupling the milk container to the milkcleaning manifold which is located in the fridge. The milk container and milk container hose and coupling will not be cleaned with the daily clean process. However, they are located in the fridge and have to be cleaned with the weekly clean process (see above) when they change or fill up the milk container.

The cleaning container can be placed besides the fridge under the counter.

Fig. 6 shows the above-mentioned multifunction outlet head 13b for use in a scheme according to Fig. 1 in more detail.

The outlet head 13 according to this embodiment comprises attachments to the above- mentioned line 10a, which is right downstream of the above-mentioned valve 12; in this representation the inlet from that line into the outlet head is designated with 10a.

Also, the outlet head according to this embodiment comprises attachments to the above- mentioned circulation line 14c, which connects to the above-mentioned cleaning container 14, and this representation the outlet to that line from the outlet head is designated with 14c. For the circulating cleaning process, the outlet head 13, which is illustrated in the top portion of the figure, is closed manually by attaching the clean head cup 13a.

The clean head cup 13 a comprises a grip portion 25 on the bottom, in this case with circumferential grooves for ease of handling. There is an upper circumferential portion 26 with a larger diameter, and with an inner diameter to engage with the outer tip portion of the outlet head 13.

For ease of handling and attachment, this clean head cup 13a in the upper circumferential portion 26, is provided with one or several magnetic elements 28, which are held in a groove 29, which is provided in the inner surface of the upper circumferential portion 26. Since the tip portion of the outlet head 13 is made of metal, by way of these magnetic elements 28, the clean head cup 13a can be very easily attached to that portion by simply approaching from the bottom and then by way of magnetic forces the clean head cup 13a will automatically engage and attach to the tip portion of the outlet head 13.

Also different attachment mechanisms like snap-in mechanisms are possible, however the magnetic attachment has the advantage of easy self-engagement attachment and also ease of removal without additional manipulations being necessary to for example a release a snap-in mechanism.

The clean head cup 13a provides for a return cavity 27, which is closed to the bottom at the bottom end of the upper circumferential portion 26, and the function of which will be detailed further below. In a radial direction this return cavity 27 extends well beyond a circumferential tip portion 39 of an inner skirt 31 of the outlet head, preferably even beyond the tip portion of an outer skirt 30 of the outlet head.

The outlet head has the above-mentioned inlet 10a into the outlet head, and the above- mentioned outlet 14c from the outlet head to the cleaning container 14. Both, for ease of assembly, are provided in the top portion with attachment portions 40 for connection elements 42, which connection elements 42 are suitable and adapted for directly being connected with tubes of the device.

For example, the inlet 10a will be connected by way of a short tube to the above-mentioned valve 12. However, the connection element 42 on that inlet 10a may also be directly part of the valve 12 to avoid additional tubing between the outlet head 13 and the valve 12. Typically, the connection elements 42 are sealed with respect to the wall of the outlet head by way of circumferential sealing rings 41 .

Liquid/foam to be dispensed in the dispense mode entering by way of the inlet 10a into the outlet head flows downward in the corresponding channel bordered by wall 38, which in the bottom portion widens to a larger diameter terminal outlet area 33.

In the transition region between the upper, more narrow channel 10a and this larger diameter terminal outlet area 33, there is provided a central flow guiding element 34, which is located in that transition region in the axial center thereof, and which is held in place in that region by way of small radial connection elements 35. In in this case there are provided three radial connection elements 35 at 120° spacing connecting the central flow guiding element 34 with the wall 38.

The central flow guiding element 34 has an upper spherical region 36 towards the inlet 10a, and a lower converging region 37 towards the actual outlet opening. The function of this flow guiding element 34 is to provide for a controlled flow of liquid/foam depending on its flow speed, density and air content. If there is only little liquid with a high density, it will be guided by the central flow guiding element 34, and will flow/dripple off at the very tip of the lower converging region 37. Like that it can be avoided that an uncontrolled flow takes place for example along the circumferential walls of the terminal outlet area 33 on the inner skirt 31 forming that circumferential wall. If on the other hand there is a high flow and/or foam, the full volume of the inlet 10 a as well as of the terminal outlet area 33 will be filled, and liquid/foam will exit as a wide diameter stream having essentially an outer diameter of the terminal outlet area 33, i.e. there will be stall of the flow at the edge of the inner skirt 31 , or rather more specifically, at the tip 39 thereof.

A problem associated with such a configuration, in particular if milk is involved, is that residual milk deposits will result at and around tip portion 39, even also at an outer periphery of the inner skirt 31.

To allow for cleaning also of these outer portions of the outlet head, it is provided with an additional outer skirt 30, which is circumferential and concentrical to the inner skirt 31 but has a larger diameter, so that a contiguous circumferential interspace 32 forms between the two skirts. It is this interspace 32 which is connected to the outlet 14c mentioned above, such that in the mode to cleaner container, if the outlet head cup 13a is attached , cleaning liquid entering by way of 10a flows across the central flow guiding element 34 and into the terminal outlet area 33, along the inner wall of the inner skirt 31 , enters the above-mentioned return cavity 27 provided by the clean head cup 13a, and travels around the tip 39 of the inner skirt 31 into the circumferential contiguous interspace 32. It then travels upwards and into the above-mentioned outlet 14c, so that the inner skirt 31 is cleaned on the radial inner side as well as outer side thoroughly. The return cavity 27 can also be structured sufficiently wide that also the tip portion of the outer skirt 30 or even beyond is subjected to cleaning liquid in that mode.

LIST OF REFERENCE SIGNS

1 water 12 valve (3/2 or 2x 2/2) for water

2 water inlet valve flash or dispensing

2a backflow prevention element 13 outlet head

2b backflow prevention element 13a clean head cup

2c line from water inlet valve to 13b multifunction outlet head milk supply line 14 cleaning container

3 clean return valve 14a dosing pump cleaner

3a cleaning line from clean 14b cleaner bottle return valve 3 to milk supply 14c circulation line between 13 line and 14, outlet from outlet

4 manifold valve block (1+n) head

4a milk cleaning manifold 15 drink cup

5 cooling unit, fridge 16 waste water drain line

6 liquid (milk) container (1+n) 16a wastewater container

6a line from milk container to 4a 17 flow meter fresh water control

6b line from 4a to 4 18 check valve air line

7 conductivity sensor 19 lower control plate

8 impeller pump 20 upper control plate

9 homogeniser 21 outlet for milk froth

10 extractor system 22 shortcut between 10a and

10a line between 10 and 13, inlet 16a into outlet head 23 shortcut between 10a and

11 heating elements, thickfilm 14c heating system 24 connecting line grip portion of 13a 37 lower converging region of 34 upper circumferential portion 38 wall of 10a channel in 13 of 13 a 39 circumferential tip portion of return cavity in 13 a 31 magnetic element 40 attachment portion for groove for magnetic element connection element outer skirt of 13 41 sealing ring inner skirt of 13 42 connection element contiguous circumferential 43 automatic tablet dispenser interspace between 30 and Xa to outlet position 31 Xb to drain position terminal outlet area of 13 Xc circulation position central flow guiding element Xd closed position connection element upper spherical region of 34

Claims

1. Liquid food dispensing system with at least one supply of milk (6), at least one element (10) for the treatment of milk and at least one outlet head (13) for dispensing the liquid food, wherein the system further comprises at least one cleaning container (14) for at least one cleaning liquid, with at least one cleaning line (3a) connecting the cleaning container (14) with a line (6a) connecting the supply of milk (6) with said element (10) for the treatment of milk, at least one supply of water (1), wherein the outlet head (13) can be connected to the cleaning container (14) with at least one circulation line (14c) allowing for circulation of cleaning liquid and/or water in a circulation path through the cleaning container (14), by way of the cleaning line (3a), through the element (10) for the treatment of milk, the outlet head (13) and back to the cleaning container (14).

2. System according to claim 1 , wherein the outlet head (13) is provided with means to switch at least between a dispense mode (Xa), in which liquid food is dispensed, and a circulation mode (Xc), in which the output of a line (10a) from the element (10) for the treatment of milk is redirected to said circulation line (14c).

3. System according to claim 2, wherein the outlet head (13) is either further provided with means to switch in addition to a drain mode (Xb), in which the output of said line (10a) from the element (10) for the treatment of milk is redirected to waste (16), and wherein preferably it is further provided with means to switch to a closed mode (Xd), in which said line (10a) from the element (10) for the treatment of milk is blocked, the circulation line (14c) is blocked and the line (16) redirecting to waste is blocked or wherein the outlet head (13) is provided with means to allow for manual attachment or automatic engagement of an outlet head cup (13a), which closes the outlet opening of the outlet head (13) and provides for a return cavity (27), such that in circulation mode, output from said line (10a) from the element (10) for the treatment of milk is redirected to said circulation line (14c) by way of said return cavity (27), wherein preferably the outlet opening of the outlet head (13) is provided with a circumferential inner skirt (31) and a circumferential outer skirt (30) with a contiguous circumferential interspace (32) between these skirts (30, 31), and wherein this contiguous circumferential interspace (32) is connected to the circulation line (14c), and/or wherein further preferably the outlet head cup (13a) is provided with at least one magnetic element (28) allowing for self-engaging attachment of the outlet head cup (13a), to the, preferably metallic, outlet head (13), and/or wherein further preferably in the tip portion the outlet head (13) is provided with a widening terminal outlet area (33), and wherein at the transition from said line (10a) from the element (10) for the treatment of milk to this widening terminal outlet area (33), there is provided at least one, preferably central, flow guiding element (34).

4. System according to claim 3, wherein the outlet head takes the form of a multifunction outlet head (13b) which comprises at least two elements (19, 20), which are mechanically movable relative to each other to switch between dispense mode, circulation mode, drain mode and closed mode, wherein preferably the least two take the form of at least one plate (19) which can be rotated relative to another plate (20).

5. System according to any of the preceding claims, wherein it further comprises a cleaner container (14b), which is connected to the circle, preferably by way of a pump (14a) for introducing cleaner into the cleaning container (14).

6. System according to any of the preceding claims, wherein the system comprises at least two different milk containers (6) or at least one milk container and at least one further liquid food container, and wherein said cleaning line (3a) connects the supplies of milk (6) an/or the supply of milk and at least one further liquid food container by way of a milk cleaning manifold (4a), with at least two inlets for liquid food (6a), at least two outlets for liquid food (6b), at least one inlet for the cleaning line (3a), and an inlet for a water line (2a), the cleaning and water lines being fluidly connected to each of the liquid food lines, wherein preferably at the inlet side for the liquid food (6a) elements (2a) for preventing backflow are provided.

7. System according to any of the preceding claims, wherein it is a system for providing milk froth, either exclusively or in combination with providing liquid coffee and combinations of milk froth and liquid coffee.

8. System according to claim 7, wherein the element (10) for the treatment of milk comprises at least one pump (8) and at least one homogeniser (9).

9. System according to any of the preceding claims, wherein in the circulation path there is provided at least one conductivity sensor (7) for measuring the conductivity of circulating or stationary cleaning liquid.

10. Method for operating a system according to any of the preceding claims, wherein for the cleaning of the system the outlet head (13) is connected to the cleaning container (14) and cleaning liquid is circulated through the cleaning container (14), by way of the cleaning line (3a) through the element (10) for the treatment of milk, the outlet head (13) and back to the cleaning container.

11. Method according to claim 10, wherein before circulation by way of the supply of water (1) the circulating path is filled with water replacing milk in the circulating path and dispensing the milk in the circulating path to waste container (16a), and wherein while keeping the supply of water (1) the circulation is established until a sufficient amount of cleaning liquid is circulating and contained in the cleaning container (14), followed by circulation and/or soaking and/or heating, preferably until a conductivity sensor (7) detects appropriate conductivity values in the circulation liquid.

12. Method according to claim 11 , wherein circulation is followed by further supply of water (1) and accompanied or followed by emptying the circulating path to a waste container (16a) by corresponding automatic switching of a multifunction outlet head (13b).

13. Method according to any of the preceding claims 10-12, wherein there is further provided a cleaner container (14b), and wherein before circulation cleaner is introduced into the circulating path, preferably into the cleaning container (14) from that cleaner container (14b).

14. Method according to any of the preceding claims 10-13, wherein it comprises at least one soaking phase, in which the circulating path is filled with cleaning liquid above room temperature, and wherein the cleaning liquid is not circulated.

15. Use of a method according to any of the preceding claims 10-14 for cleaning of system for the generation of milk froth.