A method and system for cleaning beverage dispensing systems

Abstract

A cleaning system for a beverage dispensing system, comprising: a mixing tank 13 for mixing powder detergent with a liquid, the tank having an upper section (50, fig. 3) and a lower section (52, fig.

Description

Field of the Application. The present application relates generally to beverage dispensing systems and more particularly to methods of cleaning them. Background Systems for dispense of beverages can be considered to consist of three main parts. The first part is a storage container or reservoir for storing the beverage. These storage containers when used in the context of alcoholic drinks, for example beer, are often referred to as a keg. These kegs are typically located in a storage area, cold room or cellar. Secondly a beverage transport system is used to convey the beverage to a dispense location, for example a bar, through pipes or lines. Thirdly, a dispenser, commonly referred to as a tap, delivers beverage from the pipesMines into a container, e.g. a glass, for consumption. Although usage varies, pipes are generally rigid whereas lines are taken to be flexible. In practise, a system may employ a combination of both. In the present application, the term conduit is employed and may be taken to include both rigid pipework and flexible lines or hoses. A beverage dispensing system may also have additional components for example to cool the beverage and provide insulation of the cooled beverage in the dispense lines as the beverage is conveyed to the dispenser. Installations of beverage dispensing systems vary but a common installation might typically position the beverage storage containers in a chilled storage area or cellar. The beverage may then be additionally cooled in proximity to the storage area before being transported to the dispense location. Alternative installations may provide the additional cooling of the beverage in proximity to the dispense location. Another possibility is to not use a chilled storage area but to transport the beverage from the storage container at ambient temperature before cooling the beverage in proximity to the dispense location. Figure 1 shows an exemplary beverage dispense system. The beverage dispense system comprises beverage storage containers 1, located in a beverage storage area, cold room or cellar 2. The beverage transport system typically comprises a number of beverage conduits 5 which may be a combination of pipes or hoses, FOB detectors 3 and one or more beverage chillers 7. Each beverage conduit 5 is connected to a corresponding storage container by a connector 14, commonly referred to as a “dispense head” for carbonated beverage products. Other components may be included as required by the application or specific installation. The beverage lines\pipes may be insulated in regions 6 in order to maintain the temperature of the beverage during its time in the transport system. Beverage is served from a beverage tap 8 in a remote location, i.e. a bar area 4. A single beverage dispense path containing the components mentioned previously from dispense head 14 through to the tap 8 is typically referred to as a dispense line. Beverages are typically dispensed from the storage container by means of gas pressure which pushes the beverage out of the container and into the beverage dispense lines. The beverage containers are configured so that liquid is dispensed from the bottom of the container so the addition of pressurised gas above the level of the liquid forces the beverage out of the container. Gas enters the storage container through the dispense head 14 and is supplied from a source of pressurised gas 15 through a gas delivery conduit 16. Additionally pumps may be used to pump the beverage through the beverage dispense lines. Some beverages which do not use gas pressure may only use pumps to draw beer from the container to the beverage tap. As storage containers empty, gas can enter the beverage dispense line and potentially travel up the line to the dispenser. For beverages which are carbonated i.e. contain dissolved gas, this can result in loss of beer due to the formation of foam or FOB (foam on beer) when beverage is reintroduced into the dispense line. FOB is unsuitable for consumption and is therefore wasted. To stop this occurring beverage lines are typically fitted with a device to stop gas ingression into the beverage dispense lines. These devices are commonly referred to as FOB detectors and typical examples include UK patents GB1.357.953 or Porter Lancastrian, GB2,286,581 of Francisco Moreno Barbosa and US 5,564,459. They are typically configured as a liquid filled chamber that is positioned near the start of the beverage dispense line. Beverage enters the chamber near the top and exits near the bottom of the fob detector. A buoyant float in the chamber rises to the top when the chamber is filled with liquid and lowers as the liquid level drops when gas is introduced. As the liquid level drops the float drops into and seals a valve of the chamber preventing further gas ingress into the beverage dispense lines. Other fob detectors are known which operate indirectly. These indirect fob detectors use a sensor to determine the position of the float in the chamber and actuate a separate valve, to control the flow of beverage when the position of the float has been detected as having fallen to a particular level. UK patent GB2,404651 is an example of this system. In some arrangements the beverage conduit splits to connect multiple taps to the same dispense head. Typically this is done downstream of the FOB detector. In this way one beverage storage container can supply a plurality of taps in different dispense areas. It will be appreciated that in operation at any one time, the transport system for delivering beverages from the beverage storage container to the tap will contain a volume of beverage liquid. The volume of liquid incorporates the beverage resident in the beverage lines, the beverage cooler and the FOB. This liquid is in contact with the internal surfaces of the transport system. Typically volumes of beverage in a single dispense conduit are in the range 1-2I. This volume may vary depending on the distance between the beverage storage location and dispense point. Additionally beverages storage at warmer temperatures will need to be cooled from a greater temperature differential to the dispense temperature, this typically requires the beverage to pass through longer cooling coils in the beverage chiller 7. These factors affect the volume of beverage in a beverage dispense line and in some examples such as sports or music venues and airports the volume of a single dispense line may be in excess of 51. Some beverages are shipped in storage containers as a sterile product to increase their storage life. Others are “live” (i.e. un-pasteurized or not sterile filtered) and contain yeasts from the brewing process. The beverage transport system is generally open (i.e. not sealed from its external environment) and there is the potential for ingress of yeasts and bacteria through the inlet where it is connected to the beverage storage container and at the outlet through the beverage tap. Additionally the flow of liquid through the transport system can distribute contaminating organisms throughout the rest of the transport system. While some of these are suspended in the liquid, others settle and grow on the surfaces of the transport system to form bio-film. The rate of growth of yeasts and bacteria is dependant on a number of factors including temperature, material type, surface roughness and the nutrient content of the beverage etc. If the growth of yeasts and bacteria is sufficiently large it can produce unsavoury and off flavours in the dispense product, making it unsuitable for consumption. Therefore the transport system and beverage tap require regular cleaning to remove the biofilm growth and ensure the quality of the dispense product. During such cleaning processes, detergent fluids are typically flushed through the transport system and tap and then any residual detergent is rinsed away with potable water. Cleaning of the transport system does not produce sterile standards of contamination given the open nature of the dispense system. Instead, the aim is to remove and reduce the biological growth to levels where re-growth does not impact dispensed product quality between cleaning cycles. There are a number of approaches taken to cleaning the beverage transport system. Typically detergent solution is introduced and dispensed through the transport system in a similar manner to beverage dispense. This is subsequently removed from the system by rinsing with water. There are numerous processes used for cleaning the transport system with varying parameters such as time, detergent type and concentration, flowing or static detergent exposure, the use of rinse water before as well as after detergent introduction. However the majority of processes include a process of filling the transport system with detergent, a static or “soak” period and its subsequent removal by flushing with rinse water. Introduction of the detergent may be performed sequentially into the transport system beverage conduits or in parallel, i.e. one conduit may be done after another or they may be done at the same time. Alternative approaches to cleaning also include the recirculation of detergent though the dispense systems to increase the mechanical effect of the cleaning fluid in removing contaminating material. Still alternative methods also introduce heating of the recirculating liquid to further enhance the cleaning action. The minimum volume of detergent cleaning solution used to clean the beverage lines is typically greater than the total liquid volume of the dispense system that is being cleaned. This allows for filling the complete volume of the dispense systems as well as any additional conduits required to deliver the detergent. Depending on the type of cleaning process used it may be required to use multiples of the dispense system liquid volume of detergent cleaning solution. For efficiency and ease of use the detergent solutions used for cleaning beverage lines are typically produced in one of two different ways. Firstly by using a concentrated liquid form of the cleaning detergent containing the cleaning chemicals in the appropriate proportions. This is then diluted by adding it to a larger volume of water (typically in a range of 1-5% volume to volume). Secondly by use of a solid powder comprising the constituent cleaning chemicals. This is then dissolved in water to create the detergent cleaning solution in the required chemical concentration. Concentrated liquid detergents have the advantage of the being simple to use as they mix readily with water. However they have two main disadvantages in that the concentrated liquid represents a safety hazard for handling or shipping. In addition there may be limitations on the solubility of some chemicals that limit the concentration they can effectively be contained in a concentrated solution. Solid or powder form detergent poses less of a safety risk for handling or shipping but has the main disadvantage that the chemicals must be dissolved completely in water. This later disadvantage is greater when larger volumes of liquid are required as it becomes impractical to agitate the liquid volume to accelerate the dissolving of the chemical powder. Figure 1 includes an exemplary automated cleaning system 10. The system is connected to a water supply 12. The cleaning system in this example provides dilute detergent solution and rinse water to a common manifold 11 commonly referred to as a “cleaning ring main”. On the cleaning ring main there are outlet connectors 9 commonly referred to as “cleaning sockets”. The cleaning ring main may take a number of configurations including a single line with one inlet, equally it may be configured to form a loop so that detergent solution and rinse water is provided from either end. For cleaning, the dispense head is removed from the storage container and connected to a cleaning socket. Detergent solution and rinse water may then enter the beverage conduit 5. The configuration shown in Figure 1 is exemplary and one that is used commonly in practice to somewhat automate the supply of mixed detergent and rinse water. Other configurations are possible and are used in practice. Further components may be used to additionally automate the cleaning process (e.g. a drainage system from the beverage tap). Still further features may be included to ensure process conformance by monitoring time, sensor data etc and this may be recorded for future use. The process may also be performed manually by mixing the detergent solution and providing a pump to deliver it to the beverage conduits. Different configurations are possible, thus in Figure 2, the dispense conduits are connected to a source of line cleaning solution 18 through a common inlet manifold or “cleaning ring main” 11. The taps are connected by drainage lines 26 to a wastewater drain 17. The taps may be located in one or more areas and at one or more levels. In Figure 2 they are shown exemplary at a ground floor area 4g and a first floor dispense area 4i. Methods to improve and automate the cleaning process have taken a number of approaches. Examples of automation include US10,392,238, US2,098,525, US2,016,926 and US4,572,230. Some alternatives use a mechanical device or “squeegee” reciprocally moving up and down the beverage conduits (e.g. US2,827,070, US2,413,626 and US2.331,460). Still other methods pulse the flow of the detergent solution in the transport system to help remove the biofilm growth from the surfaces (e.g. US8,069,866 and GB2,414,284A). To date automatic beverage cleaning systems have typically used concentrated liquid detergents that are diluted with water to the required chemical solution concentration to clean the beverage lines. This dilution to the required concentration is typically done in a number of different ways including: 1. Adding a measured quantity of the concentrated liquid detergent to a tank of water that is then pumped to the cleaning ring-main. 2. Directly injecting a controlled amount of the concentrated liquid detergent with an electrically driven pump into the water supply directed to the cleaning ringmain. 3. mixing the concentrated liquid detergent through a mechanical proportional mixing device into the water supply directed to the cleaning ringmain. 4. The use of vortex injection where the passage of the water flow through a restricting orifice produces a negative ambient pressure downstream of the orifice and draws a proportionate supply of concentrated detergent into the water supply directed to the cleaning ring-main. There may also be alternative means of obtaining the required dilution of the concentrated liquid form of the cleaning detergent. The ease with which concentrated liquid detergent can be mixed with water to form the diluted detergent concentration for cleaning beverage lines has made it the most used form for automatic beverage line cleaning devices. Beverage line cleaning using solid powder detergent mixtures have typically only been used in manual processes. In these manual processes a measured amount of powdered detergent is added to a volume of water contained in a tank. A lid is used to seal the tank and then the tank is manually shaken in order to distribute and dissolve the powdered detergent in the volume of water. Manual mixing places practical limits on the size of the tank that can be handled by a person, in addition there may be health and safety legislative limits on the weight and size of any container that person may use to manually mix and dissolve the powder detergent. These limitations on the volumes of chemical cleaning solution that can be produced at any one time means that typical beverage dispense systems may require multiple containers of chemical cleaning solution to be mixed in order to clean the dispense system. Automated mixing of larger volumes of water and detergent has typically not been used for beverage line cleaning processes. In industrial environments dissolving larger volumes of powdered chemical typically use motor driven mechanical agitators to move the body of water in a mixing tank to keep chemical powders in suspension while they dissolve. The present application is directed at providing a solution for the efficient and effective dissolving of powdered beverage line cleaning chemicals in a tank. Summary Accordingly, the present application provides a mixing tank for dissolving powdered chemical detergent. The dissolved chemical detergent is for use with an automatic beverage line cleaning system for cleaning a beverage dispense system as might be found is a bar, hotel or restaurant. The tank is configured so to be primarily cylindrical, positioned with its rotationally symmetric axis in a vertical direction. The lower section of the tank is primarily conical in form. A water outlet and inlet are configured so that the water outlet is positioned at the bottom of the tank at or in proximity to the symmetrical rotational axis of the cylinder. The water inlet is positioned above the water outlet and is directed so that the inlet water flow is tangential and substantially horizontal with respect to the inner wall of the tank. When a liquid is drawn into a water intake, liquid flow transitions from uniform flow to non-uniform flow where there are gradients in the fluid velocity. This can cause the formation of vortices often referred to as “intake vortices”. In the current invention, to mix the tank, water is recirculated from the water outlet back to the water inlet by a pump. The position of the water outlet substantially at the centre of the bottom of the tank, the use of a cylindrical tank with a conical shape to the lower part and the direction of the water inlet above the water outlet and substantially tangentially to the side wall of the tank enhances the effect of vortex formation. This has the effect of the complete volume of liquid in the tank to be in motion without any additional mechanical means for stirring or agitation. In order to dissolve the powdered chemical detergent and to not draw undissolved powdered chemical into the water outlet, a filter screen is positioned upstream of the water outlet in order to stop large undissolved particulates from entering the water outlet directly. By recirculation of the water in the tank, the formation of a liquid vortex and the velocity of the liquid flow in the vortex allows the powdered chemical detergent to be held in suspension and to dissolve more rapidly. During recirculation the complete liquid volume in the tank is in motion. Any undissolved powder detergent that has settled to the bottom of the tank after being introduced is subject to sheer forces from the rapid liquid motion that brings it into suspension and it is subsequently dissolved. Once dissolved the dilute detergent is used by the automatic beverage line cleaning system to clean one or more beverage lines. The mixing tank forms part of an automatic beverage line cleaning system. This beverage line cleaning system controls the liquid flow and volume, in and out of the tank by use of valves, sensors and a pump. The production of the detergent solution for cleaning the beverage lines, from the powdered chemical detergent, forms part of the process or cycle which involves other process steps or stages. This may include first flushing, with water, any residual beverage from the dispense system, introducing the detergent solution into the beverage dispense one or more times, each introduction followed by a wait period to allow the detergent solution chemicals to react with any contamination in the systems, a final rinse of the detergent solution from the beverage dispense system with water. Further embodiments are set out specifically in the claims, which follow. Additional embodiments, features and advantages will become apparent from the detailed description and the drawings which follow, in which: Description of Drawings Figure 1 is an exemplary beverage dispense system known in the art. Figure 2 is an exemplary beverage dispense system known in the art for supplying beverage from a storage area below two separate bar areas on different levels; Figure 3 is an exemplary mixing tank according to a first aspect of the present application; Figure 4 is an exemplary beverage cleaning system with the mixing tank of Figure 3; Figure 5 is a flowchart for the operation of a exemplary line cleaning process using a mixing tank for powdered chemical detergent, as the flowchart is large, Figure 5 has been split over two sheets labelled Figure 5(A) and Figure 5(B); Figure 6 A Piping and Instrumentation Diagram (P&ID) of an exemplary automatic beverage line cleaning system. For convenience, the same reference numerals are used with like features between the figures in the drawings. Detailed Description: The inventor of the present invention has realised that a practical impediment to using solid powder forms of the chemicals for cleaning beverage dispense systems is the availability of an efficient and effective means of mixing and dissolving the cleaning chemicals in water to produce sufficient quantities of chemical cleaning solution to clean typical beverage dispense systems that are used in typical hospitality venues. In addition any means must be suitable for installation and use in a hospitality environment (bar, restaurant, hotel etc) where beverage dispense systems are typically found. As stated previously a single beverage dispense line typically contains 1-21 of liquid. Typically dispense installations have a plurality of dispense lines. The number depends on the installation but can typically from 2 to 20 dispense lines. Typical detergent chemical cleaning cycles clean all lines at one time or with installations containing a larger number of dispense lines these are grouped into manageable number of dispense lines. Typical processes used in the industry require the dispense lines to be completely filled at least twice with new chemical detergent cleaning solution. When filling the line with an automatic line cleaner 18 liquid is pumped into the lines in parallel. Individual differences in dispense line conduction of liquid requires that an excess of liquid is required to be pumped in order to completely fill all the dispense lines as some lines will fill more slowly than others. These requirements give rise to the need for typical tank capacities in the range 10-1001. In reality different tank sizes will be used for different installations to avoid excessively large installations where they are not required. The recent increase in low and no alcohol beverages forms of typically alcoholic beverages has given rise to a new requirement for cleaning. The absence of alcohol in these beverages makes them more susceptible to spoilage and a requirement for more frequent cleaning to preserve their dispense quality as well as their low or no alcohol level as spoilage organisms can form alcohol when they grow in the beverage and on the beverage line surfaces. For this reason there has developed an industry requirement for an application where a single or low number of lines are cleaned. This application would typically require a smaller tank in the range 5-101. Accordingly, in general terms, the tank capacity is likely to be in the range of 5 to 1001 for most practical use in cleaning beverage dispensing systems. Realising this the present inventor provides a solution for this by inventing a means to mix and dissolve powder chemical detergent in a tank based on recirculated flow of the liquid in the tank. This allows larger volumes of liquid detergent cleaning solutions to be produced than could be made practically my manual means and also eliminates the need for more costly and complex additional mechanical mixer devices such as paddles that are typically used in industrial applications to dissolve chemical powders in water. The invention uses the geometry of the mixing tank, the position and direction of the tank liquid inlet and tank liquid outlet, and by recirculatory pumping of the liquid from the tank outlet to the tanks inlet to form an “intake vortex” in the tank. This “intake vortex” substantially allows the volume of liquid in the tank to be in motion at liquid flow rates from the outlet to inlet that are substantially less than the volume of liquid in the tank. This provides a more efficient and effective process for dissolving the powder chemical in the water. The process of mixing and dissolving the powder chemical detergent forms part of the beverage systems cleaning process. Figure 3 shows an exemplary mixing tank 13. The tank suitably has an upper section 50 and a lower section 52. The upper and lower sections are arranged along a central vertical axis with the lower section extending downward from the cylindrical upper section. The tank is shaped to assist in the formation of a vortex in liquid present in the tank. As will be explained below, the vortex is formed as liquid is recirculated out of and back into the tank. The lower section is substantially rotationally symmetric about the central vertical axis. Similarly, the upper section may be substantially rotationally symmetric about the central vertical axis. The lower section 52 is suitably conical or frusto-conical shaped in nature. The upper section may be cylindrical as shown in Figure 3 or may be an extension of the conical shape of the lower section. The conical angle is generally at most 45 degrees from the vertical axis and more typically 30 degrees from the vertical. The conical section typically encompasses between 30% and 60% of the overall tank height. The conical nature of the lower section enhances the formation of a mixing vortex for a liquid present in the tank. The vertical proportion of the tank that is conical shaped may extend to include the majority of the tank height or as shown less than 50% of the tank depending. An orifice 23 is provided where powdered chemical detergent may be introduced to the tank. This is suitably provided in a top surface of the tank closing the top of the upper section. A lid 19 may be provided to close the orifice. The lid may be hinged. When in operation, mixing and dispensing detergent the lid is preferably closed (Figure 4). To ensure the lid is closed during operation, a sensor 24, suitably a contact switch, may be provided as an interlock to halt the operation of the system if the lid is opened while the process is in operation. The tank has an inlet 20. The inlet is suitably positioned at the side of the tank. The inlet is suitably positioned at a position close to the border between the upper and lower sections. The inlet may be angled so that incoming liquid is directed tangentially to the inside wall of the tank. This positioning and direction is such that it enhances the effect of vortex formation. The Earth’s Coriolis effect will have beneficial effect on the formation of the vortex. Preferably in the northern hemisphere the liquid inlet direction would be in a clockwise direction then viewed from the top of the tank and in an anticlockwise direction for the southern hemisphere. The tank has an outlet 19 positioned at the bottom. For reasons of vortex efficiency, the outlet is positioned substantially in the centre of the tank. A filter mesh screen 25 may be positioned in the lower section to cover the opening of the outlet. The screen is suitably selected to have a mesh size that prevents powdered detergent entering the outlet 19. Powder sizes that dissolve easily are typically in the range or 0.5mm to 1 mm in size. A filter mesh screen with open mesh dimensions typically less than 50% of this particulate size is used to ensure particulates of the chemical detergent powder mixture only pass through once they have started to dissolve. The tank may have a number of measurement sensors such as level sensors 21, 22 to provide information on the liquid level in the tank. Such level sensors can form part of a control arrangement for the mixing and cleaning process. It will be appreciated by those skilled in the art, that there are several different methods of measuring / estimating the liquid level in the tank including simple switched sensors at fixed levels attached to the side of the tank, or sensors that use other methods such as ultrasonic reflection to measure liquid level including the liquid level from the bottom of the tank or the distance to the liquid level from the top of the tank. It will equally be appreciated that there are a number of other methods by which the liquid level may be inferred for the purposes of control of the powder mixing and cleaning process, for example a flowmeter 32 may be used to provide a measure for the volume of liquid in the tank. Equally, the flowmeter may be used for the purposes of control of the powder mixing and cleaning process. Figure 4 shows and exemplary beverage cleaning system using the tank shown in Figure 3. Water ingress into the tank is controlled by a tank inlet valve 28 connected by a conduit or piping to the tank inlet 20. Water from the tank outlet 19 passes through an outlet conduit to a tank outlet valve 27. This outlet conduit is also fitted with a check valve 35 to stop backflow of liquid. The inlet water supply 12 may pass through a number of stages. For example, a pressure regulator 20 may be provided to control water pressure or a strainer / filter 34 may be provided to prevent ingress of physical contaminants. The inlet supply may also be provided with one or more check valves 35 to ensure that contamination does not back flow into the water supply, for example in the case of a component failure. The supply of water into the system is suitably controlled by a water inlet valve 33. A pump 30 pumps liquid to tank inlet. This liquid may be water from the water inlet 12 if the inlet water valve 33 is open or water, potentially mixed with detergent, from tank outlet 19 if the tank outlet valve 27 is opened. Liquid from the tank may be pumped either to the tank inlet 20 if the tank inlet valve 28 is open or to a “cleaning ring main” 11 if the outlet valve 29 is open. A flowmeter 32 may measure the volume of liquid and the liquid flow rate into the pump 30, suitably through the pump inlet manifold 38. A conductivity sensor or switch measures the conductivity of the liquid passing though the pump inlet manifold 38 and indicates the presence of dissolved detergent in the liquid. An exemplary mode of operation will now be described with reference to four main modes of operation. A first mode is for flushing or rinsing residual beer or detergent from the beverage dispense system. In this first mode, the water inlet valve 33 and the cleaning outlet valve 29 are open. The pump is on. As a result, water is pumped directly through the beverage dispense system of cleaning ring main 11, cleaning sockets 9, beverage conduits 5 to the taps 8 and finally into a drain 17. The volume of water being pumped and its flow rate can be monitored by the flowmeter 32. A second mode is for filling the tank. In this second mode, the water inlet valve 33 is open and the tank inlet valve 28 is open. The pump is on and water flows into the tank. The volume of liquid entering the tanks can be controlled by either the flowmeter 32 or the level sensor 22. A third mode recirculates the liquid in the tank. In this third mode, the tank inlet valve 28 and tank outlet valve 27 are open. With the pump on, liquid flows from the tank outlet 19 to the tank inlet 20. The flowmeter 32 measures the liquid volume and flow rate and the conductivity sensor 31 detects the presence of dissolved detergent. In this third mode of operation the flow of liquid into and out of the tank along with the position and orientation of the inlet and outlet co-operate to form a vortex within the tank. The formed vortex incorporates substantially the whole volume of liquid within the tank. The action of the vortex helps to disperse and dissolve any powdered detergent placed in the tank. During operation, undissolved powder is concentrated by the vortex action towards the centre in proximity to the tank outlet on the filter screen 24 where it may be dissolved. Advantageously, relatively low liquid flow rates from the pump, of the order or 5 l / min can produce a vortex within a 50I tank. This method of mixing and dissolving the detergent offers advantages as it can be implemented without the complexity of separate mechanical mixing or agitation device and utilises the pump already required for pumping dissolved detergent as part of the cleaning process. A fourth mode of operation pumps liquid from the tank. In this fourth mode, the tank outlet valve 27 and cleaning outlet valve 29 are open. The pump 30 is on and liquid flows from the tank outlet 19 to the cleaning ring main 11. The flowmeter 32 measures the volume and flow rate of liquid. Using the system above and the modes of operation described, the system can clean beverage lines by completing a number of process steps. An exemplary process for performing a line cleaning operation is now described utilising a sequence of steps. The automatic line cleaning system 18 employs a controller 37 to control the sequence of steps. The controller receives signals from the various sensors indicating a status or measurement depending on the sensor. In response to the signals, the controller operates the pump and valves to complete the sequence of steps in the process. In practicality the number of these steps and their duration may vary to provide a reliable process. In addition the order or inclusion of some of the steps may vary depending on the complete process implemented. For example in the current description the first process step involves operating in the previously described first mode to flush or rinse any residual beverage from the beverage dispense system before switching to the second mode and filing the tank and mixing / dissolving the detergent. In some implementations this may done after the dissolved detergent preparation, in yet other implementations it may not be carried out and detergent introduced directly into the beverage dispense systems while residual beverage is still present. An operator would typically introduce the powdered chemical detergent into the tank 13 through the lid orifice 23 at the start of the process. Typically the tank would already contain a prefilled quantity of water. This prefilled quantity of water fulfils two purposes. Firstly to help the introduced powdered detergent to disperse and not agglomerate into clumps or solidify on the filter screen 24 and secondly as dissolving of most cleaning chemicals is an exothermic process it limits the danger of excessive heat production where large amount of detergent may contact a small amount of water. Typically, the first process step involves flushing or rinsing residual beverage from beverage dispense system. This utilises the first mode of operation described previously. This is followed by a second process step of filling water into the mixing tank 13 using the second mode of operation. In a third process step, the previously introduced detergent is mixed and dissolved in the tank. Mixing and dissolving the detergent involves the recirculation of the liquid in the tank as described in the third mode of operation. These filling and mixing steps may involve more then one repetition. For example, an implementation may involve initially dissolving the detergent with a lower volume of water in the tank such that it is only partially filled. This facilitates mixing and dissolving with higher liquid vortex flows as the proportionate pumped turnover of the liquid in the tank is higher than with a full tank. Subsequently the tank is filled further and recirculating again to dilute the dissolved concentrated detergent to the final solution for cleaning the beverage dispense system. A conductivity meter 31 measures that the correct amount of detergent is present in the dissolved detergent. Once the tank of dissolved powder detergent is prepared it is pumped into the beverage dispense system as described in forth mode of operation. The volume of liquid pumped into the dispense system is measured by the flowmeter 32 or limited by the level sensor 21 located in proximity to the bottom of the tank to ensure the tank is not emptied and air is pumped through the system. Typically, after filling the beverage dispense system the detergent mix is left to reside in the beverage dispense system for a fixed period of time, (commonly referred to as soaking), before pumping further detergent or flushing the detergent from the beverage dispense system. In the exemplary cleaning system described here, and before rinsing detergent from the beverage dispense system, the tank is suitably first rinsed of residual detergent. This involves a sequence of steps of emptying the tank, part filling the tank with water, recirculating the water though the tank, tank inlet and outlet valves, pump and flowmeter. This rinsed liquid is then pumped through the beverage dispense system until the tank is emptied. The final rinse of the beverage dispense system uses the first mode of operation described at the start of the process. The flowmeter 12 measures the volume of liquid and flowrate. The controller ensures that sufficient volume of rinse water is provided to the beverage dispense systems to ensure all dilute detergent is rinsed from the systems. Finally, the tank 13 is part filled with a measured volume water so that it is ready for its next cleaning cycle and the introduction of powdered detergent. It will be appreciated that several modifications may be made to the system. For example, in the exemplary arrangement described above, it is assumed that an operator will manually add detergent powder to the tank through opening 23. However, equally this step may be performed by mechanical means. For example, a hopper may be provided above the tank pre-filled with detergent powder and an auger may be provided to cause the detergent to move from the hopper into the tank. It will be appreciated that where detergent is introduced manually, it is simpler to have a single step for this. Accordingly, the tank would be sized to be at least the volume of the beverage dispensing system. In contrast, where powder detergent is added automatically, it is possible to reduce the size of the tank by repeating the detergent mixing step, and pumping the mixed liquid detergent after each mixing step into the beverage dispensing system. The advantage of the system of the present application is that it is extremely compact and uses a minimum of additional components to a conventional cleaning system for a beverage dispensing system. In the drawings of the application, the reference signs correspond to the following features: 1. Beverage Storage Containers 2. Cold Room or Cellar 3. FOB detectors 4. Bar area 5. Beverage Conduits 6. Insulated Conduits 7. Beverage Chiller 8. Beverage Tap 9. Cleaning Sockets 10. Automatic Cleaning System 11. Cleaning Ring Main 12. Water Supply 13. Tank 14. Beverage Storage connector 15. Pressurised Gas Supply 16. Gas deliver conduit 17. Wastewater drain 18. Exemplary Automatic Line Cleaner 19. Tank Lid 20. Pressure Regulator 21. Lower Level Sensor 22. Upper Level Sensor 23. Lid orifice 24. Interlock 25. Filter Screen 26. Drainage Conduit 27. Tank Outlet Valve 28. Tank Inlet Valve 29. Cleaning Outlet Valve 30. Pump 31. Conductivity Sensor 32. Flowmeter 33. Water Inlet valve 34. Inlet Filter 35. Check Valves 36. Pump Control 37. Controller 38. Pump inlet manifold 39. Mixing vortex 50. Upper section of tank 52. Lower section of tank

Claims

1. A cleaning system for a beverage dispensing system, comprising: a mixing tank for mixing powder detergent with a liquid, the tank having an upper section and a lower section arranged along a central vertical axis with an inlet positioned in the upper section and an outlet provided in the lower section, the mixing tank being shaped to assist in the formation of a vortex in the liquid in the tank;an arrangement of valves and conduits;a first pump;wherein the arrangement of valves and conduits may be configured in one mode of operation to fluidly connect the outlet to the inlet through the first pump, such that when the pump is operated, pumped liquid flows from the outlet to the inlet and the motion of the pumped liquid in the tank causes a vortex to form assisting the mixing of powder detergent with the liquid.

2. A cleaning system according to claim 1, wherein the lower section has a conical orfrusto conical shape.

3. A cleaning system according to claim 2, wherein the conical angle is less than 45 degrees from the vertical axis.

4. A cleaning system according to claim 3, wherein the conical angle is about 30 degrees from the vertical.

5. A cleaning system according to any preceding claim, wherein the height of the lower section is between 30% and 60% of the overall tank height comprising that of the upper and lower sections.

6. A cleaning system according to any preceding, wherein the upper section has a cylindrical shape.

7. A cleaning system for a beverage dispensing system, according to any preceding claim, wherein in another mode of operation, the arrangement ofvalves and conduits allows for the liquid detergent mix to be pumped into the beverage dispensing system.

8. A cleaning system according to claim 7, wherein the first pump is operable to cause the pumping of the liquid detergent mix into the beverage dispensing system.

9. A cleaning system according to any preceding claim, wherein the volumetric capacity of the mixing tank is less than 1001.

10. A cleaning system according to any preceding claim, wherein the volumetric capacity of the mixing tank is greater than 5I.

11. A cleaning system according to any preceding claim, further comprising a mesh filter positioned in the lower section above the outlet.

12. A cleaning system according to claim 11, wherein the mesh size is selected to be half the diameter of the diameter of the particles of detergent powder used.

13. A cleaning system according to claim 11, wherein the mesh size of the mesh filter is selected to have a diameter less than .5mm suitably less than ,25mm.

14. A cleaning system wherein the inlet is configured to direct liquid from the inlet in a direction tangentially to the inside wall of the tank.Application No: GB2412827.4 Examiner: Evie WaltonClaims searched: 1-14Date of search: 23 January 2025Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X 1-8 and 10-14 US 2010 / 0229899 Al (ANDERSEN) Paragraph [0066] and fig. 2 X 1 and 3- 14 JP 2018138161 A (CUP&CINO KAFFEESYSTEM VERTRIEB GMBH &CO KG) Paragraph [0017] X 1, 3-6 and 10-14 CN 115815241 A (CHINA WANBAO ENG CO LTD) Fig. 7 X 1, 3-6 and 10-14 CN 107297350 A (SHANGHAI ELECTRICAL GAS TURBINE CO LTD) Fig. 1 X 1, 3-6 and 10-14 CN 213223617 U (CHINA PETROLEUM &CHEM CORP) Fig. 1Categories:X Document indicating lack of novelty or inventive step A Document indicating technological background and / or state of the art. Y Document indicating lack of inventive step if P Document published on or after the declared priority date but combined with one or more other documents of before the filing date of this invention. same category. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:www.gov.uk / ipoInternational Classification:Subclass Subgroup Valid From B08B 0009 / 027 01 / 01 / 2006 B08B 0009 / 032 01 / 01 / 2006www.gov.uk / ipo

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