GB2614933A

GB2614933A - Foam detection device

Info

Publication number: GB2614933A
Application number: GB2206201.2A
Authority: GB
Inventors: Wyn-Davies Alan; Hopewell Simon
Original assignee: Dfx Tech Ltd
Current assignee: Dfx Tech Ltd
Priority date: 2022-04-28
Filing date: 2022-04-28
Publication date: 2023-07-26
Anticipated expiration: 2042-04-28
Also published as: GB2614933B; GB202206201D0

Abstract

A FOB detector 100 has two level sensors 116,120. The bottom (top) sensor 116 (120) detects whether beverage is present at a lower (upper) level of the chamber. When beverage is not detected at the lower level, beverage outlet valve 108 closes. When beverage is detected at the upper level, waste outlet valve 112 closes. The waste outlet may open when beverage is not detected at the lower level. The beverage outlet may open when beverage is detected at the upper level. A temperature sensor may inform sensor 116,120 detection thresholds. The sensors 116,120 may detect cleaning fluids. The sensors may extend into the FOB detector vertically or horizontally (Fig. 2). The level sensors 116,120 may be electrical, optical or acoustic. A single level sensor may be used instead of two.

Description

FOAM DETECTION DEVICE

Technical Field

The present invention relates to foam detection in beverage dispense systems. In particular, but not exclusively, the present invention relates to devices for detecting the foam on beer (fob) that is produced when a beer supply, such as a keg or barrel, is exhausted.

Backciround A beverage dispense system is used to deliver a beverage from a beverage supply to a dispensing site through a beverage line. By creating a pressure difference between the dispensing site and the beverage supply, the beverage is drawn through the beverage line from the beverage supply to the dispensing site. For example, beer from a keg or cask located in a pub cellar is typically drawn through a beverage line to a tap in the pub's bar using a mechanical pump or a pressurised gas system. Once beverage has been delivered to the dispensing site, the beverage line remains substantially full of beverage so long as there is sufficient beverage remaining in the beverage supply to replace any beverage that has been dispensed. When the beverage supply is exhausted, gas from the beverage supply may be drawn into the beverage line together with residual beverage to fill the beverage line with a foam, commonly referred to as "foam on beer" or "fob" (and this term may be used for beverages other than beer). After the beverage supply has been replaced, the beverage line must then be refilled with beverage and the fob flushed out before dispensing can recommence, which results in some of the beverage being wasted.

To prevent foam or gas from filling the beverage line fully, a fob detector (i.e. foam detector) is often installed in the beverage line close to the beverage supply. When fob enters the detector, the beverage line is automatically closed to interrupt the passage of the foam along the beverage line towards the dispensing site. A traditional mechanical fob detector comprises a small chamber, typically cylindrical in shape, into which beverage is introduced through an inlet in the base of the chamber. Within the chamber is a "float" that can move up and down depending on the level of beer within the chamber. When the beverage supply is exhausted, foam begins to form at the top of the chamber (as the foam is less dense than the beverage it replaces) and the float moves under gravity towards the base of the chamber to seal a beverage outlet through which the beverage (or foam) would otherwise leave the chamber. A manually operated waste valve is provided at the top of the chamber to allow fob and gas to be discharged from the fob detector after the beverage supply has been replaced. A mechanical actuator is also provided to manipulate the float so as to re-open the outlet and allow the float to be displaced upwards by fresh beverage entering the chamber through the inlet.

In order to reset the fob detector, manual intervention is typically required to carry out the following steps: (i) the exhausted beverage supply is disconnected from the beverage line; (ii) a new beverage supply is connected to the beverage line; (iii) the manual waste valve at the top of the fob detector is opened to release fob from the top of the chamber until the chamber is once again filled with beverage; (iv) the mechanical actuator is then activated to break the seal between the beverage outlet and the float, so that the float moves back to the top of the chamber; and (v) once the float has been released, the mechanical actuator is then returned to its normal position for dispensing.

Other fob detectors are also known in which an electrical or optical sensor is used to close a solenoid valve in response to fob being detected.

Summary

According to a first aspect of the present invention there is provided a foam detection device for a beverage dispense system. The device comprises a chamber having an inlet through which to receive beverage, a beverage outlet through which to expel beverage and a waste outlet through which to expel gas and/or foam. The device also comprises a first sensor for detecting whether beverage is present at a lower level of the chamber and a beverage outlet valve operable to close the beverage outlet in response to a signal from the first sensor indicative of beverage not being detected at the lower level of the chamber. The device further comprises a second sensor for detecting whether beverage is present at an upper level of the chamber and a waste outlet valve operable to close the waste outlet in response to a signal from the second sensor indicative of beverage being detected at the upper level of the chamber.

The device is oriented in use such that the upper level and the waste outlet are above the lower level and the beverage outlet. During dispensing of the beverage, the chamber is generally filled with beverage. However, over time, some foam/gas may collect in the upper region of the chamber such that the presence of beverage in the upper region is no longer detected by the second sensor. However, dispensing may continue until the presence of beverage in the lower region of the chamber is no longer detected by the first sensor and the beverage outlet valve is closed. Conversely, when the device is being refilled with beverage, the presence of beverage in the lower region will be first detected by the first sensor. Then the presence of beverage in the upper region will be detected by the second sensor and the waste outlet valve then closed. Thus, the use of the first and second sensors allows the device to respond appropriately to the chamber being emptied of beverage and refilled with beverage. By contrast, for foam detection devices having only one sensor for controlling both valves, there is a trade-off between closing the beverage outlet in response to only relatively small amounts of foam/gas collecting in the upper region of the device or closing the waste outlet whilst a relatively large amount of foam/gas remains in the chamber when it is being refilled with beverage.

The waste outlet valve may be operable to open the waste outlet upon receipt of a signal from the first sensor indicative of beverage being not detected at the lower level of the chamber.

The beverage outlet valve may be operable to open the beverage outlet in response to a signal from the second sensor indicative of beverage being detected at the upper level of the chamber.

The sensors may be configured to detect beverage based on one a more electrical parameters of the beverage, such as a dielectric constant or a conductivity of the beverage. Each of the sensors may comprise a respective electrode. Each sensor may be configured to detect a change in a voltage on the electrode caused by beverage contacting or not contacting the electrode. Each sensor may be configured to apply an AC voltage to the electrode. The device may further comprise one or more reference electrodes and each sensor may be configured to measure the voltage (or a change in voltage) on the corresponding electrode relative to a voltage on one of the reference electrodes. The one or more reference electrodes may be located between the respective electrodes of the sensors. For example, the device may comprise a reference electrode provided between the respective electrodes of the sensors that serves as the reference electrode for each sensor. Such an arrangement with a common reference electrode may help ensure that the magnitude of the voltage (or voltage change) measured by each sensor is similar. Alternatively, the electrode of the first sensor may be located between the electrode of the second sensor and the one or more reference electrodes. Each sensor may detect whether a voltage (or a voltage change) corresponding to when beverage spans or does not span the sensor electrode and the reference electrode. Each of the electrodes may extend into the chamber through a side wall of the chamber. The electrodes may be parallel to one another and/or extend horizontally into the chamber. Preferably, the electrodes may be pins arranged along and extending perpendicularly to a vertical line.

The foam detection device may further comprise a temperature sensor configured to measure a temperature of the beverage in the chamber, wherein the first sensor and/or the second sensor is configured to detect the presence of beverage based on a parameter measured by the sensor exceeding a threshold value, the threshold value being determined at least in part from the temperature measured by the temperature sensor.

The first sensor may be configured to detect whether cleaning fluid is present at the lower level. The beverage outlet valve may be operable to close the beverage outlet in response to a signal indicative of cleaning fluid being detected by the first sensor.

Alternatively or additionally, the waste outlet valve may be operable to open the waste outlet in response to a signal from the second sensor indicative of cleaning fluid being detected at the upper level of the chamber.

The second sensor may be configured to detect whether cleaning fluid is present at the upper level. The waste outlet valve may be operable to open the waste outlet in response to a signal indicative of cleaning fluid being detected by the second sensor.

The inlet may be configured to deliver beverage into the chamber at a location that is above the lower level and the beverage outlet. The inlet may comprise a pipe extending into the chamber and configured to direct beverage away from the lower level and the beverage outlet. The pipe may, for example, extend upwards passed the lower level and/or the upper level to deliver beverage to an upper region of the chamber.

The beverage outlet valve and the waste outlet valve may be solenoid valves. The beverage outlet valve may be a latching valve. The latching valve may be configured to remain open without requiring power to be supplied to it, thus avoiding heat being generated by the beverage outlet valve during normal dispensing operation. External walls of the chamber may be thermally insulated (e.g. with an insulating foam, such as polystyrene or polyurethane foam) to (further) prevent warming of beverage as it passes through the device.

The waste outlet valve may be a non-return valve. This reduces the risk of the chamber being contaminated.

The foam detection device may further comprise a communication device for transmitting a signal to a remote location, the signal comprising data indicative of one or more of: whether the beverage outlet valve and/or the waste valve is open, an identity of a beverage in the chamber, the presence of a cleaning fluid, and a temperature of beverage in the chamber.

According to a second aspect of the present invention, there is provided a beverage dispense system comprising the foam detection device of the first aspect. The system further comprises a beverage supply connected to the inlet of the foam detection device and a beverage dispense device connected to the beverage outlet of the foam detection device.

According to a third aspect of the present invention, there is provided a method of replacing an exhausted beverage supply of a beverage dispense system according to the second aspect. The method comprises: closing the beverage outlet valve in response to the beverage not being detected at the lower level of the chamber by the first sensor; replacing the exhausted beverage supply with a non-exhausted beverage supply; providing beverage from the non-exhausted beverage supply to the chamber through the inlet whilst the waste outlet valve is open and the beverage outlet valve is closed; closing the waste outlet valve in response to beverage being detected in the upper region of the chamber by the second sensor; and opening the beverage outlet valve.

Replacing the exhausted beverage supply with a non-exhausted beverage supply may in some cases be accomplished using an additional valve provided between the exhausted beverage supply and the inlet of the chamber. The additional valve is operable to connect the non-exhausted beverage supply to the inlet whilst simultaneously disconnecting the exhausted beverage supply from the inlet. The additional valve may be a three-way valve, for example, although it will be appreciated that more than two beverage supplies may be used, in which case the additional valve may be operable to connect one of each of the beverage supplies to the inlet in turn.

The additional valve is preferably operated automatically (i.e. without manual intervention) in response to a signal received from the first and/or second sensors. For example, the additional valve may be operable to, in response to a signal from the first sensor indicative of beverage not being detected at the lower level of the chamber: disconnect the exhausted beverage supply from the inlet and connect the non-exhausted beverage supply to the inlet. Such operation may allow rapid, automatic, switching between beverage supplies (e.g. keg replacement), in combination with automatic venting of the foam detection device. Interruptions to dispensing caused by beverage supply replacement and venting may therefore be minimised.

A beverage supply may be said to be exhausted when there is a large increase (e.g. more than 10% or more 50%) in the amount of foam (fob) that has entered the chamber of the foam detection device compared with beverage.

Brief Description of the Drawinqs

Figure 1 is a vertical cross section view of a foam detection device according to an embodiment of the present invention; and Figure 2 is a schematic vertical cross section view of a foam detection device according to another embodiment of the present invention.

Detailed Description

The present disclosure addresses or at least alleviates some of the issues with known foam detectors.

Figure 1 shows a foam detection device 100 comprising a chamber 102 having an inlet 104 in the form of an upstanding pipe that extends into the chamber 102 through its base, and a beverage outlet 106 provided in a sidewall of the chamber 102 and positioned towards the base of the chamber 102 (although the beverage outlet 106 could be provided in the base instead in some implementations). The inlet 104 is connectable to a beverage supply, such as a keg, barrel or cask (not shown), whilst the beverage outlet is connectable to a beverage line that delivers the beverage to a dispense site (not shown). The beverage outlet 106 comprises a solenoid valve 108 that can be operated to selectively open or close the outlet 106. The valve 108 is preferably a latching valve that can be maintained in an open state without requiring power (or at least less power than is required to open or close the valve), so that the beverage in the chamber 102 and the beverage outlet 106 is not heated by the valve 108. The arrows within Figure 1 depict the flow of beverage during normal dispensing operation.

The device 100 further comprises a waste outlet 110 provided towards the top (i.e. in an upper region) of the chamber 102 and though which gas, foam and/or beverage can be expelled. In this case, the waste outlet 110 extends through the top (i.e. the "ceiling") of the chamber 102, although it could instead extend through a sidewall of the chamber 102 in other implementations. The waste outlet 110 comprises a solenoid valve 112 that allows the outlet 110 to be selectively opened or closed as required. The valve 112 may be a latching valve, but as it is typically opened relatively infrequently (e.g. when the beverage supply is exhausted or during cleaning cycles) a non-latching valve can be used instead.

The device 100 also comprises a first fluid level sensor 116 for detecting whether the beverage reaches a predetermined lower level (height) within the chamber 102 and a second fluid level sensor 120 for detecting whether the beverage reaches a predetermined upper level (height) within the chamber 102. The sensors 116, 120 and the valves 108, 112 are typically controlled by a processor (not shown) attached to or embedded within the device 100.

The second fluid level sensor 116 comprises (in this example) a pair of stainless steel electrodes 116A, 116B that extend into the chamber 102, in this case through the top of the chamber 102, and which are spaced apart by a small distance, e.g. around 0.5-3 cm. The second sensor 116 further comprises circuitry (not shown) configured to apply an alternating (AC) voltage having a frequency of around 32 kHz to one of the electrodes (the sensor electrode 116A), and to ground the other electrode (the reference electrode 116B). The circuity is configured to measure the voltage on the sensor electrode 116A relative to the reference electrode 116B. The sensor electrode 116A is capacitively coupled to the reference electrode 116B such that the voltage measured on the sensor electrode 116A depends on the dielectric constant of the medium between the electrodes, with different voltages being produced depending on whether the medium is beverage (such as beer or lager) or foam/gas. Thus, when the fluid level of the beverage remains below the bottom of the electrodes 116A, 116B, such that the headspace of the chamber 102 is filled with gas or foam, a different voltage is measured compared to when the beverage level extends above the bottom of the electrodes 116A, 116B. The electrodes 116A, 116B may be configured to detect when the beverage fills more than 50%, more than 80%, or substantially the whole of the chamber 102, for example. An integrated circuit suitable for use in sensor 116 is the LM1830 Fluid Detector available from National Semiconductor.

The first fluid level sensor 120 is similar to the second sensor 116, and comprises circuitry configured to measure the AC voltage on a sensor electrode 120A relative to the reference electrode 116B. The reference electrode 116B is therefore common to both sensors 116, 120, in this example (although separate reference electrodes for each sensor 116, 120 can also be used). As the sensor electrode 120A of the second sensor 120 extends less far into the chamber 102 through the top of the chamber 102 than the sensor electrode 116A of the first sensor 116, the predetermined lower level for beverage detected by the second sensor 120 is less than the predetermined upper level for beverage detected by the first sensor 116. The second sensor 120 is preferably configured so that the predetermined lower level of beverage that it detects is greater than a height of the beverage outlet 106 above the base of the chamber 102. In some cases, the electrodes 116A, 116B may be configured to detect when the beverage fills more than 20%, or more than 40% of the chamber 102, for example.

In normal use (i.e. during dispensing of beverage), beverage flows from the beverage supply through a beverage line (not shown) connected to the pipe of the inlet 104 and upwards through the pipe to fill the chamber 102 with beverage. The solenoid valve 108 of the beverage outlet 106 is kept open, so that the beverage flows out of the chamber 102 through the beverage outlet 106 and onwards to the dispense site through a further beverage line (not shown). The solenoid valve 112 of the waste outlet 110 is kept closed to prevent beverage leaving the chamber 102 through the waste outlet 110. As the beverage travels through the device 100, small amounts of gas entrained in or desorbed from the beverage inevitably collect at the top of the chamber 102, e.g. as a foam 102G in the headspace above the fluid level 118 of the beverage. The gas/foam 102G may in some cases be detected by the second sensor 120, but provided the beverage supply does not become exhausted, this gas/foam generally remains trapped at the top of the chamber 102 and does not affect the beverage being dispensed.

When the beverage supply is exhausted, the fluid level 118 of the beverage drops and the top of the chamber 102 fills with gas/foam. The change in fluid level 118 is detected by the first sensor 116, which sends a corresponding signal to cause the beverage outlet valve 108 to close, thereby preventing the gas/foam from entering the beverage line downstream of the device 100. Thus, the beverage remaining in the beverage line downstream of the device 100 may be retained for dispensing once the beverage supply has been replaced, which may avoid quantities (e.g. several pints) of beverage being wasted. The device 100 may further comprise an indicator, such as a light emitting diode, to provide a visual indication to users that the beverage supply has been exhausted.

After the beverage supply has been replaced (or otherwise replenished), the device 100 needs to be reset. In the present example, this is achieved by a user operating a reset switch (not shown) located on or adjacent to a connector used to connect the beverage supply to a beverage line attached to the inlet 104 of the device 100, or alternatively, on or adjacent to the device 100 itself. When the reset switch is operated, a signal is sent to the processor, which responds by opening the waste valve 112 so that the foam can be flushed out of the chamber 102 by the incoming beverage. As the chamber 102 fills with beverage, the fluid level 118 rises, causing the second sensor 120 to detect beverage between the sensor electrode 120A and the reference electrode 116B, and to send a signal to the processor to close the waste valve 112. In some cases, the processor may delay closing the valve for a short time after the signal is received from the second sensor 120 in order to allow the fluid level 118 to rise further, thereby reducing the amount of gas that remains trapped in the chamber 102 (although in other cases the valve may be closed almost instantaneously). Alternatively or additionally, the waste valve 112 may be closed and then re-opened briefly and closed again in one or more bursts to vent the last of the gas in the chamber 102. Such pulsed operation may promote or accelerate the separation of foam/bubbles from the beverage (e.g. the "settling" of the beverage) within the chamber 102, e.g. by generating vibrations within the chamber 102 to cause bubbles to aggregate with one another and/or become dislodged from the chamber walls. After the waste valve 112 is closed (and any further venting completed), the processor opens the beverage outlet valve 108 so that beverage can be expelled from the device 100 through the beverage outlet 106 and along the beverage line to the dispense site.

Figure 2 shows a vertical cross section view of a foam detection device 200 that is similar to the foam detection device 100 of Figure 1. The foam detection device 200 is generally cylindrical in shape and comprises a chamber 202, an inlet 204 and a beverage outlet 206. The solenoid valves shown in Figure 1 are not shown in Figure 2, but may be fitted to the inlet 204 and the beverage outlet 206, which extend from the body of the device, and the inlet204 and beverage outlet 206 may be threaded to allow them to be screwed into corresponding tapped holes on the valves to form a fluid-tight connection (although other types of fitting, such as push-fit fittings, may be used for this purpose instead).

Alternatively, the valves may be spaced apart from the device 200 and connected to the inlet 204 or beverage outlet 204 by a length of pipe or tubing.

The foam detection device 200 comprises a removable cap 222 that is fitted to the top of the chamber 202 and fixed in position by bolts spaced around the circumference of the cap 222 and extending through the cap 222 into threaded holes in the top of the chamber 202. When fixed in position, the cap 222 compresses an 0-ring 224 to form a seal between the cap 222 and the top of the chamber 202 in order to maintain pressure within the chamber 202 when the waste outlet 212 is closed. A non-return valve 226 is provided in the outlet 212 to prevent potential contaminants from entering the chamber through the waste outlet 212.

The device 200 comprises a circuit board 228 (e.g. a printed circuit board, PCB) attached to a sidewall of the chamber 202. The circuit board 228 comprises a processor (not shown) for controlling the valves as described above, a first fluid level sensor 216 comprising a sensor electrode 216A and a reference electrode 216B, and a second fluid level sensor 220 comprising a sensor electrode 220A and the reference electrode 216B. The sensors 216 and 220 and associated circuitry function in the same way as the sensors 116, 120 of the foam detection device 100 of Figure 1. The electrodes 216A, 216B, 220A extend horizontally into the chamber 202 through the sidewall of the chamber 202, rather than through the top of the device 200. Such an arrangement results in a more compact (i.e. narrower) device and allows the cap 222 to be removed and replaced without damaging the electrodes and/or the processor. Having the electrodes 216A, 2168, 220A extend through the sidewall allows shorter electrodes to be used and also allows the electrodes to be spaced apart from one another to a greater extent, which may for example reduce interference between the two sensors 216, 220 in some cases. The heights of the devices 100, 200 are preferably greater than their widths (e.g. diameters) as this allows the difference in heights of beverage within the chamber 102 measured by the sensors 216, 220 to be greater.

Although the reference electrode 216B is shown in Figure 2 as being located between the sensor electrodes 216A, 220A, other arrangements may alternatively be used (i.e. arrangements in which the height of the reference electrode 216B relative to the beverage outlet 106 is not intermediate the heights of the sensor electrodes 216A, 220B). For example, the sensor electrode 216A of the first fluid level sensor 216 may alternatively be located between the sensor electrode 220A of the second fluid level sensor 220 and the reference electrode 216B, with the reference electrode 216B located below the sensor electrodes 216A, 220A. Such an arrangement allows the height of the sensor electrode 216A of the first fluid level sensor 216 relative to the beverage outlet 106 to be increased, so that the sensor electrode becomes isolated from surrounding beverage more quickly as the fluid level decreases, thereby allowing more time for the valve 108 to be closed before gas/foam enters the beverage line downstream of the foam detection device 200. By contrast, when the sensor electrode 216A of the first fluid level sensor 216 is above the reference electrode 216B, even after the fluid level has below the level of the reference electrode 2168, beverage surrounding the sensor electrode 216 may provide sufficient capacitive coupling to the walls of the chamber 202 and inlet 204 to prevent a signal being generated to close the valve 108 until after the fluid level has fallen further.

Whilst the description above has focussed on the use of fluid level sensors that determine the capacitance of a medium between electrodes, many other types of fluid level sensor can be used, such as optical sensors or acoustic sensors, for example.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It would be apparent to one skilled in the relevant art(s) that various changes in form and detail could be made therein without departing from the spirit and scope of the invention. For example, in some implementations the first sensor and second sensor may be provided by a single sensor that is configured to determine whether beverage is present at an upper level of the chamber and whether beverage is present at a different, lower level of the chamber.

Claims

CLAIMS: 1. A foam detection device for a beverage dispense system, the device comprising: a chamber having an inlet through which to receive beverage, a beverage outlet through which to expel beverage and a waste outlet through which to expel gas and/or foam; a first sensor for detecting whether beverage is present at a lower level of the chamber; a beverage outlet valve operable to close the beverage outlet in response to a signal from the first sensor indicative of beverage not being detected at the lower level of the chamber; a second sensor for detecting whether beverage is present at an upper level of the chamber; and a waste outlet valve operable to close the waste outlet in response to a signal from the second sensor indicative of beverage being detected at the upper level of the chamber.
2. A foam detection device according to claim 1, wherein the waste outlet valve is operable to open the waste outlet upon receipt of a signal from the first sensor indicative of beverage not being detected at the lower level of the chamber.
3. A foam detection device according to claim 1 or 2, wherein the beverage outlet valve is operable to open the beverage outlet in response to a signal from the second sensor indicative of beverage being detected at the upper level of the chamber.
4. A foam detection device according to any one of the preceding claims, wherein the sensors are configured to detect beverage based on one or more electrical parameters of the beverage, such as a dielectric constant or a conductivity of the beverage.
5. A foam detection device according to claim 4, wherein each of the sensors comprises a respective electrode, each sensor being configured to detect a change in a voltage on the electrode caused by the beverage contacting or not contacting the electrode.
6. A foam detection device according to claim 5, wherein each sensor is configured to apply an AC voltage to the electrode.
7. A foam detection device according to claim 5 or 6, wherein the device comprises one or more reference electrodes and each sensor is configured to measure the voltage on the corresponding electrode relative to a voltage on one of the reference electrodes.
8. A foam detection device according to claim 7, wherein the one or more reference electrodes are located between the respective electrodes of the sensors.
9. A foam detection device according to claim 7, wherein the electrode of the first sensor is located between the electrode of the second sensor and the one or more reference electrodes.
10. A foam detection device according to any one of claims 7 to 9, wherein each of the electrodes extends into the chamber through a side wall of the chamber.
11. A foam detection device according to any one of the preceding claims, further comprising a temperature sensor configured to measure a temperature of the beverage in the chamber, wherein the first sensor and/or the second sensor is configured to detect the presence of beverage based on a parameter measured by the sensor exceeding a threshold value, the threshold value being determined at least in part from the temperature measured by the temperature sensor.
12. A foam detection device according to any one of the preceding claims, wherein the first sensor is configured to detect whether cleaning fluid is present at the lower level and the beverage outlet valve is operable to close the beverage outlet in response to a signal indicative of cleaning fluid being detected by the first sensor.
13. A foam detection device according to any one of the preceding claims, wherein the second sensor is configured to detect whether cleaning fluid is present at the upper level and the waste outlet valve is operable to open the waste outlet in response to a signal indicative of cleaning fluid being detected by the second sensor.
14. A foam detection device according to any one of the preceding claims, wherein the inlet is configured to deliver beverage into the chamber at a location that is above the lower level and the beverage outlet.
15. A foam detection device according to claim 14, wherein the inlet comprises a pipe extending into the chamber and configured to direct beverage away from the lower level and the beverage outlet.
16. A foam detection device according to any one of the preceding claims, wherein the beverage outlet valve is a latching valve.
17. A foam detection device according to any one of the preceding claims, wherein external walls of the chamber are thermally insulated.
18. A foam detection device according to any one of the preceding claims, wherein the waste outlet valve is a non-return valve.
19. A foam detection device according to any one of the preceding claims, further comprising a communication device for transmitting a signal to a remote location, the signal comprising data indicative of one or more of: whether the beverage outlet valve and/or the waste valve is open, an identity of a beverage in the chamber, the presence of a cleaning fluid, and a temperature of beverage in the chamber.
20. A beverage dispense system comprising the foam detection device of any one of the preceding claims, the system further comprising a beverage supply connected to the inlet of the foam detection device and a beverage dispense device connected to the beverage outlet of the foam detection device.
21. A method of replacing an exhausted beverage supply of a beverage dispense system according to claim 19, the method comprising: closing the beverage outlet valve in response to the beverage not being detected at the lower level of the chamber by the first sensor; replacing the exhausted beverage supply with a non-exhausted beverage supply; providing beverage from the non-exhausted beverage supply to the chamber through the inlet whilst the waste outlet valve is open and the beverage outlet valve is closed; closing the waste outlet valve in response to beverage being detected in the upper region of the chamber by the second sensor; and opening the beverage outlet valve.