WO2024132719A1

WO2024132719A1 - Device for cooling and sterilising water for dispensing cold beverages

Info

Publication number: WO2024132719A1
Application number: PCT/EP2023/085409
Authority: WO
Inventors: Eduard PATER; Koen Standaar
Original assignee: Koninklijke Douwe Egberts B.V.
Priority date: 2022-12-19
Filing date: 2023-12-12
Publication date: 2024-06-27
Also published as: GB2625716A; GB202219146D0

Abstract

A beverage preparation device (1) comprising: a cold fluid circuit (2) comprising: a fluid inlet (3), a UV fluid treatment device (4), a chiller (6), and a fluid flow path (7) from the fluid inlet, through the UV fluid treatment device (4), and through the chiller (6). The cold fluid circuit (2) also comprises: a fluid outlet (9), a fluid return flow path (12) configured for connecting to the fluid flow path to return chilled fluid to the fluid flow path and, a valve assembly (11) operable in a first condition to direct the fluid to the fluid outlet (9) and a second condition to recirculate the fluid through the fluid flow path (7).

Description

DEVICE FOR COOLING AND STERILISING WATER FOR DISPENSING COLD BEVERAGES

Technical Field of the Invention

The present invention relates to beverage preparation devices and in particular, but not exclusively, to coffee machines.

Background to the Invention

Beverage preparation devices, and especially beverage preparation devices which are used to prepare cold liquid beverages, suffer from issues maintaining acceptable standards of hygiene. Fluids flowing through piped systems develop growth of undesirable organisms, harmful germs, or infectious agents. Furthermore, stationary fluids in such systems may develop biofilms. As such, it is necessary to reduce the levels of undesirable organisms, harmful germs, and infectious agents before dispensing fluids which are safe to consume.

Existing technologies seek to achieve this effect through use of microfilters and frequent flushing of the cold fluid system to the drain. This solution is undesirable for several reasons; the microfilters are expensive and clog up over time which has a negative impact on the reliability of the system leading to customer dissatisfaction. Furthermore, microfilters require exchanging periodically which must be carried out by a service engineer. This can become expensive over time, as well as having a negative impact on the environment. The need for frequent flushing of the cold fluid system is also a waste of fluid which could otherwise be consumed.

A further issue with such beverage preparation devices is fluid which has been standing for a period is of an insufficiently cool temperature to satisfy customers. There are some technologies currently used to address this issue such as flushing the warm fluid out of the system however, this is a wasteful process which needs to be improved.

Embodiments of the present invention seek to ameliorate these disadvantages and to provide an improved hygienic cold fluid supply for beverage preparation devices.

Summary of the Invention

According to first aspect of the invention there is provided a beverage preparation device comprising: a cold fluid circuit comprising: a) a fluid inlet, b) a UV fluid treatment device, c) a chiller, d) a fluid flow path from the fluid inlet, through the UV fluid treatment device, and through the chiller; e) a fluid outlet, f) a fluid return flow path configured for connecting to the chiller to return chilled fluid from the chiller to the fluid flow path and, g) a valve assembly operable in a first condition to direct the fluid to the fluid outlet and a second condition to recirculate the fluid through the fluid flow path via the fluid return flow path.

The beverage preparation device thus provides a means of reducing the microbial load in the cold fluid, preventing the build-up of biofilms, whilst maintaining the chilled fluid temperature to ensure the outlet fluid is of a consistently chilled temperature. The beverage preparation device does not require a breaker tank for storing fluid and hence, the beverage preparation device can be significantly more compact than other inventions disclosed in the prior art. This is beneficial for uses such as, but not limited to, for example, integrating into hot and/or chilled coffee machines.

In this description, the ‘UV fluid treatment device’ is intended to indicate a fluid treatment device which treats fluid with radiation in the UV wavelengths, in a range of between 100-400 nm and which may be divided into three bands: UVA (315-400 nm) UVB (280-315 nm) UVC (100-280 nm). In one preferred form, UVC light is used.

The valve assembly may include one or more valves. If more than one fluid outlet is provided, then there may be at least one valve associated with each fluid outlet to control fluid flow through each outlet, selectively.

The cold fluid circuit may be provided in a beverage preparation device which also includes a hot or heated fluid circuit.

Both the cold fluid circuit and the hot or heated fluid circuit may be connected to the same fluid outlet. The cold fluid circuit and the hot or heated fluid circuit may be connected to separate fluid outlets. The hot or heated fluid circuit may be connected to the cold fluid circuit. This may allow the use of hot or heated fluid to flush the cold fluid circuit.

In one form, the beverage preparation device may be operable in a chilled fluid dispensing mode. In the chilled fluid dispensing mode, the valve assembly is in the first condition and chilled fluid may leave the beverage preparation device through the fluid outlet. This fluid has already been through the UV fluid treatment device and the chiller. Fresh fluid may enter the fluid flow path of the cold fluid circuit through the fluid inlet, flow through the UV fluid treatment device, the chiller and to the valve assembly, which because the valve assembly is in the first condition, allows the chilled fluid to leave through the fluid outlet.

In one form, the beverage preparation device may be operable in a chilled fluid recirculating mode. When the beverage preparation device is operated in the chilled fluid recirculating mode (not in the chilled fluid dispensing mode or flush modes), the valve assembly is operated in the second condition. Instead of chilled fluid leaving through the fluid outlet, the chilled fluid is recirculated though the fluid return flow path.

The fluid return flow path is preferably connected to the fluid flow path. The fluid return flow path is preferably connected to the fluid flow path at any location. Preferably return flow path is preferably connected to the fluid flow path before the chiller, between the fluid inlet and the UV fluid treatment device, but it could connect after the UV fluid treatment device and before the chiller.

The fluid return flow path may pass through the chiller prior to being connected to the fluid flow path. The fluid return flow path may therefore pass through the chiller toward the valve assembly, for dispensing or recirculation, and may pass through the chiller after the valve assembly prior to connection of the fluid return flow path to the fluid flow path.

The fluid return flow path is preferably connected to the fluid flow path after the fluid inlet and before any process equipment on the fluid flow path. This would allow recirculation through all of the process equipment on the fluid flow path. A non-retum valve may be provided on the fluid return flow path. A non-retum valve may be provided on the fluid flow path after the inlet, and preferably before any process equipment and before the fluid return flow path connection.

In one form, the beverage preparation device may be operable in a flush mode. The flush mode may utilise hot or heated fluid from the hot or heated fluid circuit. The chiller will preferably be deactivated when in the flush mode so as to not cool the hot or heated fluid being used to flush the cold fluid circuit.

A controller may be provided to operate the valve assembly between the first condition and second condition to recirculate fluid through the fluid flow path via the fluid return path, at a chosen interval.

A controller may be provided to operate the second valve assembly to direct hot or heated fluid from the hot fluid circuit into and/or through the cold fluid circuit when in the flush mode. The chiller may be deactivated during the flush mode. A single controller may be provided to control the valve assembly and the second valve assembly.

The fluid may be recirculated through the fluid flow path via the fluid return path at regular time intervals. This may maintain a chilled temperature, a reduced microbial load, and prevent the build-up of a biofilm in the fluid in the fluid flow path. Thus, there may be a reduction in the volume of wasted fluid, as the need for frequent flushing to remove warm water from the fluid flow path is negated. Furthermore, customers experience greater satisfaction as their beverage is at or closer to the desired temperature. Still further, the temperature of the chilled fluid leaving the fluid outlet on demand is more likely to be at or closer to the desired temperature as the chilled fluid in the cold fluid circuit is chilled each time it is recirculated, maintaining chilled fluid in the cold fluid circuit ready to be dispensed.

The time intervals may have any length. For example, the time interval may be approximately 120 minutes, more preferably approximately 60 minutes.

The controller may shorten or lengthen the time interval based on use of the beverage preparation machine. For example, if cold fluid is being dispensed often, then the controller may increase the length of the time interval for recirculation as it less likely that cold fluid will sit for any reasonable length of time in the cold fluid circuit.

The controller may automatically engage the chilled fluid recirculating mode when the beverage preparation machine is in the chilled fluid dispensing mode but has been idle for a period. The controller may utilise a timer which is initialised after an amount of fluid has been dispensed. The timer may reinitialise after each dispensation of fluid, so that the recirculation only commences after the preferred time period has passed and the beverage preparation machine has not operated in the dispensing mode for that time period.

In an embodiment, the controller may operate the beverage preparation machine in the chilled fluid recirculating mode for a period of time prior to switching to the chilled fluid dispensing mode. This may particularly be the case if a period of time has passed between the last recirculation and any request for dispensing fluid. This may assist with dispensing fluid chilled to at or near the desired temperature.

The fluid may be a liquid. The liquid may be water or another liquid such as, but not limited to, for example, milk, and/or coffee and/or tea and/or chocolate.

The fluid flow path may be arranged and configured to drive fluid through the cold fluid circuit or allow the fluid to be driven through the fluid flow path. The fluid may be driven through the fluid flow path via mechanical or electrical means. The fluid may be driven via a pump.

The fluid may be driven through the return fluid flow path when the valve assembly is in the second condition.

Any pump or similar equipment is preferably located in the fluid flow path between the fluid inlet and the UV fluid treatment device. Any pump or similar equipment is preferably located in the fluid flow path after the connection of the return fluid flow path.

The fluid flow path may be defined including one or more fluid flow conduits such as, but not limited to, pipes, channels, or tubes. One or more portions of the fluid flow path may be insulated. One or more portions of the return fluid flow path may be insulated. The insulation may preferably operate to separate the chilled fluid from any heat sources, including any heat from a heated fluid circuit, thereby improving the overall efficiency of the device.

The fluid inlet may be configured to receive a fluid flow from a fluid source. The fluid source may be a fluid dispenser valve. The fluid dispenser valve may be, for example, a tap.

The UV fluid treatment device is arranged to radiate UV light to treat the fluid. The UV fluid treatment device may be located within the chiller. The UV fluid treatment device may be arranged at a position along the fluid flow path prior to the valve assembly. As such, any microbial load in the chilled fluid is significantly reduced. Providing a UV fluid treatment device may eliminate the need for expensive and environmentally unfriendly microfilters and improves device reliability. This is advantageous as microfilters can become blocked, resulting in reduced flow volume and reduced customer satisfaction. Furthermore, filters require a service engineer to fit replacements, which is often costly.

Any suitable UV fluid treatment device may be used according to the present invention. Preferable, the UV treatment device is a flow through device in which the fluid to be treated flows through a housing within which one or more UV lamps or light sources is provided. The UV fluid treatment device is preferably provided in an in-line configuration with a portion of the fluid flow path.

The chiller may reduce the temperature of the fluid in the cold fluid circuit. The chiller may be a heat exchanger or other means of cooling. Providing such a reduction in temperature ensures the fluid is maintained at a constant temperature, guaranteeing the temperature of fluid at the outlet. As such, customer satisfaction is improved.

The valve assembly may be operable in at least two and possibly multiple conditions. The valve assembly may preferably be operable in at least two conditions. In a first condition, the valve assembly is configured to direct fluid to the fluid outlet. In a second condition, the valve is configured to recirculate the fluid through the return fluid flow path and through the fluid flow path. As such, there is no need for two separate circuits for recirculating the chilled fluid and for dispensing the chilled fluid via the fluid outlet. Thus, the device is less complex and more compact.

The fluid outlet is configured to direct fluid out of the fluid flow path and out of the beverage preparation machine. The fluid outlet may be configured to dispense fluid into a receptacle. The receptacle may be a container configured to hold fluids such as, but not limited to, for example, a mug, a glass, or a cup. The fluid outlet may be directed toward a further process device and therefore not be an outlet from the beverage preparation machine. One or more fluid outlets may be provided. Any one or more of the fluid outlets may be connected to the fluid flow path.

The fluid outlet may be configured to be integrated into a larger beverage preparation machine. The beverage preparation machine may be, for example, a coffee machine.

The operation of the beverage preparation unit may be such that the valve assembly operates to maintain an amount of fluid in the fluid return flow path when the valve assembly switches from the first condition to the second condition. This eliminates the need for the provision of a breaker tank or other storage vessel. Instead, an amount of fluid is preferably trapped in the fluid return flow path when the valve assembly switches from the first condition to the second condition.

When in the dispensing mode, the fluid simply flows through the fluid flow path where it is treated with UV, chilled and dispensed. When the dispensing is completed, the valve assembly is preferably switched to the chilled fluid recirculating mode in which the fluid can be recirculated as and when required through the fluid return flow path and the fluid flow path without being dispensed. This may maintain the fluid at a lower temperature ready to be dispensed on demand, as required, whilst reducing the microbial load in the cold fluid, preventing the build-up of biofilms. The fluid is preferably recirculated through the UV fluid treatment device which treats the fluid with each pass and the recirculated fluid is also preferably recirculated through the chiller, maintaining the lowered temperature. According to a second aspect of the invention there is provided a cold fluid circuit unit for retrofitting to existing beverage preparation devices, the cold fluid circuit unit comprising:

A fluid flow path comprising a fluid inlet, a UV fluid treatment device located on the fluid flow path; a fluid outlet connection configured for connecting to a chiller unit, and a fluid return flow path connection configured for connecting to the fluid flow path to return fluid.

The unit may be provided in a housing. The housing may be configured to contain the components in a secure or convenient form for retrofit.

The fluid outlet connection may be configured to connect to a chiller unit. This will preferably allow fluid entering the cold fluid circuit unit to flow through the cold fluid circuit unit, particularly the UV fluid treatment device located on the fluid flow path, and then into the chiller to be chilled.

The fluid return flow path connection may allow connection of a fluid return flow path to the cold fluid circuit unit, which in turn may allow the recirculation of fluid through a cold fluid circuit.

The cold fluid circuit unit may be retrofit to a cold fluid circuit with an appropriate valve assembly provided or utilised to allow chilled fluid to be either dispensed or recirculated about a recirculation loop when not dispensed.

In an embodiment, an optional additional hot circuit may be provided. The hot circuit may comprise a fluid inlet, at least one heater, and a hot fluid flow path.

The hot or heated fluid circuit may be configured to provide hot or heated fluid to a hot fluid outlet. The fluid may be a liquid. In a preferred embodiment the liquid may be water. The fluid may be heated to boiling point. Thus, the fluid flowing out of the heater may be heat treated to above a temperature to inhibit the growth of undesirable organisms, harmful germs, or infectious agents and or to kill undesirable organisms, harmful germs or infectious agents.

The hot fluid circuit may be arranged and configured to connect with the cold fluid circuit. The hot fluid circuit may be configured in an arrangement suitable for flushing through the fluid outlet or the cold fluid circuit. The hot fluid is heat treated so it does not introduce undesirable organisms, harmful germs or infectious agents including, but not limited to, for example, bacteria, viruses, and pathogens and/or can be used to kill undesirable organisms, harmful germs or infectious agents. This is advantageous as it can be used to flush or purge any microbial load in the cold fluid circuit as needed or desired.

Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1 is a fluid flow path diagram showing the beverage preparation device in fluid recirculating mode.

Figure 2 is a fluid flow path diagram showing the beverage preparation device in fluid dispensing mode.

Figure 3 is a fluid flow path diagram showing the beverage preparation device in a flushing mode.

Figure 4 is a fluid flow path diagram showing a beverage preparation device of an alternative embodiment.

With reference to figures 1, 2, and 3 initially, a beverage preparation device 1 in accordance with a first embodiment of the invention comprises a cold fluid circuit 2 (indicated by the block arrows in Figure 2) having means to chill fluids passing through. The cold fluid circuit 2 has a fluid inlet 3, which receives fluid flow from a fluid supply source (not shown), and a UV fluid treatment device 4. The UV fluid treatment device 4 is arranged as a flow through device whereby fluid enters the cold fluid circuit 2 via the fluid inlet 3 and flows through the UV fluid treatment device 4. The UV fluid treatment device 4 is arranged in a housing 5. The housing 5 contains one or more UV light sources (not shown), which irradiate UV rays to treat the fluid passing through the UV fluid treatment device 4.

The cold fluid circuit 2 also comprises a chiller 6 which reduces the temperature of the fluid passing through the cold fluid circuit 2. The chiller 6 is located after the UV fluid treatment device 4 in this embodiment however, in other embodiments, the chiller 6 may be arranged in the same housing 5 as the UV fluid treatment device 4.

The cold fluid circuit 2 also has a fluid flow path 7 which is arranged starting from the fluid inlet 3 and passing through the UV fluid treatment device 4 and through the chiller 6. The fluid flow path 7 is defined by fluid flow conduits (not shown). In these embodiments, the fluid flow conduits are insulated tubes 8 which maintain the chilled temperature of fluid in the cold fluid circuit 2 exiting the chiller 6. The insulated tubes 8 separate the chilled fluid from any heat sources and thus improve the overall efficiency of the beverage preparation device 1.

The cold fluid circuit 2 further comprises a fluid outlet 9. The fluid outlet 9 is arranged to dispense chilled fluid exiting the cold fluid circuit 2.

The cold fluid circuit 2 in these embodiments has a means for driving the fluid through the cold fluid circuit 2 in the form of a pump 10. The pump 10 is located after the fluid inlet 3 but prior to any process equipment. In these embodiments, the pump 10 is also located on the fluid flow path 7 after the connection of the return fluid flow path 12.

The cold fluid circuit 2 also has a valve assembly 11 which is operable in at least two conditions to meet different operational requirements. The valve assembly 11 of the illustrated embodiment includes multiple flow control valves 20, 21, 22. Each of the flow control valves 20, 21, 22 is positioned on one of multiple outlets 9 from the device. This allows the device to output beverages of different types from the same fluid.

In the illustrated embodiment, a second valve assembly 19 is provided to allow hot water from the heater 15 to be utilised as a part of the optional hot flush circuit 27. The hot flush circuit also includes a flush valve 23 which, when opened, allows removal of the flush fluid from the system via the flush outlet 28.

A controller (not shown) is used to operate the require valve 20, 21, 22 of valve assembly 11 between the first and second conditions. In a first condition, an open valve in the valve assembly 11 directs fluid to the respective fluid outlet 9. The valve assembly 11 in the illustrated embodiment is comprised of three valves 20, 21, 22. Each valve is operable in a first and second condition. Each valve 20, 21, 22 controls fluid flow to an individual fluid outlet 9.

With reference to Figure 1, the beverage preparation device 1 is operable in a chilled fluid recirculation mode. The beverage preparation device 1 has a fluid return flow path 12. When the valves in the valve assembly 11 are in the second condition, fluid is recirculated and directed through the fluid flow path 7 and through the fluid return flow path 12. The fluid return flow path 12 is connected to the fluid flow path 7 to enable fluid which has not been dispensed through the fluid outlet 9 to be recirculated, treated by the UV fluid treatment device 4, and have its temperature reduced by the chiller 6. This ensures that fluid is not wasted, and the temperature of all fluid passing through the fluid outlet 9 is of a satisfactorily low temperature for customer use. In the embodiment illustrated, the fluid return flow path 12 connects to the fluid flow path 7 after the fluid inlet 3 and the non-retum valve 13 but before other process equipment including the UV fluid treatment device 4 and the chiller 6.

When in the chilled fluid recirculating mode, fluid is recirculated as required through the fluid return flow path 12 and the fluid flow path 7 without being dispensed, to maintain the fluid at a lower temperature ready to be dispensed on demand, as required, whilst reducing the microbial load in the cold fluid, preventing the build-up of biofilms.

The valve assembly 11 is operated to maintain an amount of fluid trapped in the fluid return flow path 12 when the valves in the valve assembly 11 switch between a first and second condition. This trapped fluid has already been treated by the UV fluid treatment device 4. A flow meter 30 is also provided to ensure stable dosing of the fluid through the system.

The fluid return flow path 12 is defined by fluid flow conduits linking the process equipment. The fluid flow conduits in this embodiment are insulated tubes 8 which maintain the chilled temperature of fluid in the fluid return flow path 12 which has previously passed through the fluid flow path 7 so may be at a reduced temperature. The insulated tubes 8 separate the chilled fluid from any heat sources within the beverage preparation device such as the heater 15, and thus improve the overall efficiency of the beverage preparation device 1.

The beverage preparation device 1 of a preferred embodiment has a controller (not shown) to engage the chilled fluid recirculation mode when the beverage preparation device 1 has been idle for a period. Fluid is directed periodically through the fluid return flow path 12 to maintain the reduced temperature of the fluid, the reduced microbial load of the fluid and to prevent the build-up of biofilms in the system.

A first non-retum valve 13 is located on the fluid flow path after the fluid inlet 3 but prior to the connection of the fluid return flow path 12 to the fluid flow path 7, and before the UV fluid treatment device 4 and the chiller 6 on the fluid flow path 7. The first non-return 13 valve prevents backflow of fluid out of the fluid inlet 3.

With reference to Figure 2, the beverage preparation device 1 is shown in the fluid dispensing mode. In the fluid dispensing mode, one of the valves 20, 21, 22 of the valve assembly 11 is in the first condition and chilled fluid is directed to the respective fluid outlet 9. The fluid outlet 9 usually dispenses fluid into a receptacle.

There are multiple fluid outlets 9 in this embodiment. There are multiple valves 20, 21, 22 in the valve assembly 11 operable in at least a first and second condition. When any one of the valves 20, 21, 22 are operated in a first condition, they direct fluid flow to the respective outlets 9. When all of the valves 20, 21, 22 are operated in the second condition, they direct fluid to the fluid return flow path 12.

With reference to Figure 3, the beverage preparation device 1 is shown in a hot fluid flushing mode. The beverage preparation device 1 has a hot fluid circuit 14 (shown in Figure 3 from the boiler 15 to one of the outlets 9). The hot fluid circuit 14 utilises heated fluid from the heater 15 via a fluid inlet located in the heater 15. The heater 15 heats fluid to boiling point which is above a temperature to either inhibit the growth of or to kill undesirable organisms, harmful germs, or infectious agents.

The beverage preparation device 1 has a hot fluid flow path 16 which is arranged passing through the heater 15. The hot fluid circuit 14 has a flush outlet 28 arranged to allow removal of the flush fluid leaving the hot fluid circuit 14 when flush valve 23 is open.

The hot fluid flow path 16 is defined by fluid flow conduits. In this embodiment, the fluid flow conduits are insulated tubes 8 which assist in maintaining the heated temperature of fluid in the hot fluid circuit 14 exiting the heater 15.

The hot fluid circuit 14 includes a second valve assembly 19. The second valve assembly is operable between a first and a second mode of operation. In a first mode of operation, the valve assembly 19 is in a closed configuration and prevents hot fluid from the hot fluid circuit 14 entering the cold fluid circuit 2. In a second mode of operation, the valve assembly 19 is in an open configuration and directs hot fluid into and/or through the cold fluid circuit 2 in a flush mode when valve 23 is also open.

As shown in Figure 3 (an independent of the hot fluid flush mode), hot fluid can be dispensed through any one of the fluid outlets 9 by opening a respective flow control valve 24, 25, 26 associated with the heater 15.

The hot fluid circuit 14 connects with the cold fluid circuit 2 at a point after the fluid flow path 7 but prior to the valve assembly 11. When one of the valves 20, 21, 22 of valve assembly 11 is in the first condition, the hot fluid from the hot fluid circuit 14 is directed out of the respective fluid outlet 9 and dispensed into a receptacle. When the second valve assembly 19 is in the second condition, the hot fluid is recirculated along the fluid return flow path 12. The hot fluid passes through the UV fluid treatment device 4, and the chiller 6 (which is deactivated in hot fluid flush mode), through the fluid flow conduits to flush out the insulated tubes 8 and is removed through flush outlet 28 by opening flush valve 23.

As illustrated, a second non-retum valve 18 is located on the fluid return flow path 12. The second non-return valve 18 is located prior to the connection point of the fluid flow path 7 and the fluid return flow path 12, to prevent backflow of fluids through the fluid return flow path 12.

An alternative configuration of the beverage preparation device 1 is shown in Figure 4. The major components of this embodiment are as illustrated in Figures 1 to 3. This configuration also allows fluid to flow from the inlet 3, through the non-return valve 13, the flow meter 30, pump 10, the UV fluid treatment device 4 and the chiller 6 on the fluid flow path 7. Valves V12, V22 and V32 are operable to allow the chilled and UV treated fluid to pass to a mixer associated with a coffee outlet, a mixer associated with a milk outlet, or a cold outlet as shown, as desired. These valves can also be operated to recirculate the chilled fluid back to the fluid flow path 7, via the return fluid flow path 12.

Valves VI 1, V21 and V31 are connected to the boiler 15 and are operable to allow heated fluid to pass to the mixer associated with a coffee outlet, the mixer associated with a milk outlet, or a hot outlet (also the cold outlet) as shown, as desired.

One difference between the embodiment shown in Figure 4 is that the return fluid flow path 12 is provided with a two-way valve 41, rather than the non-retum valve illustrated in Figures 1 to 3.

The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.

Claims

1. A beverage preparation device comprising: a cold fluid circuit comprising: a. a fluid inlet, b. a UV fluid treatment device, c. a chiller, d. a fluid flow path from the fluid inlet, through the UV fluid treatment device, and through the chiller; e. a fluid outlet, f. a fluid return flow path configured for connecting to the fluid flow path to return chilled fluid to the fluid flow path and, g. a valve assembly operable in a first condition to direct the fluid to the fluid outlet and a second condition to recirculate the fluid through the fluid flow path.

2. A beverage preparation device as claimed in claim 1 wherein the fluid return flow path is connected to the fluid flow path.

3. A beverage preparation device as claimed in claim 2 wherein the fluid return flow path is connected to the fluid flow path before the chiller, between the fluid inlet and the UV fluid treatment device.

4. A beverage preparation device as claimed in any one of the preceding claims wherein the fluid return flow path passes through the chiller prior to being connected to the fluid flow path.

5. A beverage preparation device as claimed in claim 2 wherein the fluid flow path passes through the chiller toward the valve assembly, for dispensing or recirculation, and the fluid return flow path passes through the chiller after the valve assembly, prior to connection of the fluid return flow path to the fluid flow path.

6. A beverage preparation device as claimed in any one of the preceding claims wherein a controller is provided to recirculate through the fluid flow path via the fluid return path at regular time intervals.

7. A beverage preparation device as claimed in claim 7 wherein the time intervals is approximately 120 minutes, more preferably approximately 60 minutes.

8. A beverage preparation device as claimed in claim 6 or claim 7 wherein the controller adjusts the time interval based on use of the beverage preparation machine.

9. A beverage preparation device as claimed in any one of the preceding claims wherein the UV fluid treatment device is arranged at a condition along the fluid flow path prior to the valve assembly.

10. A beverage preparation device as claimed in any one of the preceding claims wherein the UV fluid treatment device is a flow through device in which the fluid to be treated flows through a housing within which one or more UV lamps or light sources is provided.

11. A beverage preparation device as claimed in any one of the preceding claims wherein the beverage preparation device is operable in a chilled fluid dispensing mode, in which the valve assembly is in the first condition.

12. A beverage preparation device as claimed in claim 11 wherein fresh fluid enters the fluid flow path of the cold fluid circuit through the fluid inlet, flow through the UV fluid treatment device, the chiller and to the valve assembly, which because the valve assembly is in the first condition, allows chilled fluid to leave through the fluid outlet.

13. A beverage preparation device as claimed in any one of the preceding claims wherein the beverage preparation device is operable in a chilled fluid recirculating mode in which the valve assembly is operated in the second condition.

14. A beverage preparation device as claimed in claim 14 wherein fresh fluid enters the fluid flow path of the cold fluid circuit through the fluid inlet, flow through the UV fluid treatment device, the chiller and to the valve assembly, which because the valve assembly is in the second condition, chilled fluid is recirculated though the fluid return flow path.

15. A beverage preparation device as claimed in claim 13 or claim 14 wherein a controller automatically engages the chilled fluid recirculating mode when the beverage preparation device is in the chilled fluid dispensing mode but has been idle for a period.

16. A beverage preparation device as claimed in claim 15 when dependent on either one of clams 11 or 12 wherein the controller utilises a timer which is initialised after an amount of fluid has been dispensed so that the recirculation only commences after a particular time period has passed and the beverage preparation machine has not operated in the dispensing mode for that time period.

17. A beverage preparation device as claimed in claim 16 wherein the controller operates the beverage preparation device in the chilled fluid recirculating mode for a period of time prior to switching to the chilled fluid dispensing mode.

18. A beverage preparation device as claimed in any one of the preceding claims wherein the cold fluid circuit is provided in a beverage preparation device which also includes a hot or heated fluid circuit.

19. A beverage preparation device as claimed in claim 18 wherein the hot or heated fluid circuit is connected to the cold fluid circuit.

20. A beverage preparation device as claimed in claim 19 wherein the beverage preparation device is operable in a flush mode to utilise hot or heated fluid from the hot or heated fluid circuit to flush the cold fluid circuit.

21. A beverage preparation device as claimed in claim 20 wherein a flush mode controller is provided to operate the second valve assembly to direct hot or heated fluid from the hot fluid circuit into and/or through the cold fluid circuit when in the flush mode.

22. A beverage preparation device as claimed in claim 21 wherein a single controller is provided to control the valve assembly and the second valve assembly.

23. A cold fluid circuit unit for retrofitting to existing beverage preparation devices, the cold fluid circuit unit comprising: a. A fluid flow path comprising b. a fluid inlet, c. a UV fluid treatment device located on the fluid flow path; d. a fluid outlet connection configured for connecting to a chiller unit, and e. a fluid return flow path connection configured for connecting to the fluid flow path to return fluid.

24. A cold fluid circuit unit as claimed in claim 23 wherein the fluid outlet connection is configured to connect to a chiller unit.

25. A cold fluid circuit unit as claimed in claim 23 or claim 24 wherein the fluid return flow path connection is configured to connect to a fluid return flow path to the cold fluid circuit unit, which in turn allows the recirculation of fluid through a cold fluid circuit.