GB2336004A - Automatic vent chamber for a foaming liquid - Google Patents

Abstract

A system for delivering foaming liquids, typically drinks such as beer, comprises electronic means to monitor the condition of the liquid/foam/gas mixture in a chamber 14. The chamber is supplied with the drink from a keg 3, propelled by a gas 1. In the chamber 14, a float 5 varies its position with varying liquid level, and has means - such as a magnet or a mirror - of activating two or more level sensors 6, 7, 8. If there is excess foaming in the chamber then the ratio of liquid to gas reduces, the float is sensed to be moving downwards and an electronic circuit 12 controls a solenoid valve 10 in order to vent gas from the upper part of the chamber. Once the liquid is at its optimum height again, liquid is permitted to flow from the chamber 14 via solenoid valve 9 to the point-of-service 11. Furthermore, the system detects when the liquid supply is exhausted, and stops the flow from the chamber, thereby preventing the discharge of large amounts of compressed gas. Alternatively, the system can switch to another liquid source, such as further kegs (figure 2).

Description

2336004 FOAMING LIQUID AUTOMATIC VENT CHAMBER

Technical field of the invention

The present invention relates generally to the field of leisure and will find uses in bars, restaurants, clubs and other places where carbonated drinks are served. The invention is more particularly related to drinks dispensing equipment that is commonly found in bars, restaurants and clubs.

Background of the invention

Proprietors of bars, restaurants, clubs and other similar leisure businesses often find it difficult to control the level of foaming of "keg" drinks, These drinks (beer, lager, cider etc) include dissolved gas, often carbon-dioxide but sometimes nitrogen, other gases or a mixture of gases. As the product is transferred from the keg to the point-of- service a foam forms on the surface, this process often being called "fobbing". The foam varies in quality and amount, depending on a number of factors including the temperature of the keg, fines and glass. The layout and shape of the pipework between the keg and the point-ofservice also afrect the quality and amount of foam.

In most cases, a specialist technician will set up the pipework and will include in it some means of controlling the amount of foam. A "fob-meter" will often be part of this installation. This is simply a chamber acting as a reservoir of product, in which some foam can form. A "vent" point is usually provided at the top of the fob-meter, to allow a member of staff to release any excess gas. This is a manual process that is at best done at arbitrary intervals, and more often forgotten altogether. In many cases, inspection of a pipework installation will show that the fob-meter has been neglected and is dry (full of gas). This will lead to excess foaming at the point of service. This will cause problems in the quality of product dispensed and, importantly, wastage of product as serving staffpour away foam.

The invention provides a fully automatic "fob-meter" with a electronically controlled vent process. It will be of significant use to proprietors of bars, restaurants and clubs. It will also find use in automatic vending equipment, which hitherto has not been commonly introduced for use with keg drinks, primarily due to problems with foam. The invention applies modem electronic techniques to a process that has traditionally been limited to simple "plumbing" technology.

Page 1 Disclosure of the invention

Accordingly the present invention provides a component suitable for use as part of a system for 0 delivery of foaming liquids (typically drinks for human consumption). The said component uses electronic means to monitor the condition of the liquid/foaralgas mixture in a chamber. When an excess of gas is detected, the electronic circuit opens a vent to release a quantity of said gas.

When the keg of product is exhausted, the chamber will become empty. The electronic circuit detects this and stops the flow out of the chamber to avoid the discharge of a large amount of the compressed gas.

In larger installations, where a number of kegs of product may be served in a few hours, a variant of the invention provides the opportunity to change to a second keg, third keg etc.

The electronic circuit monitors two or more static sensors near to the chamber. The sensors can detect the presence of a float which is located inside the chamber. The float contains an object that activates the sensors, for example a magnet or a mirror. The electronic circuit contains a Finite State-Machine (ISM) which provides sequential logic. This FSM then controls the opening and closing of two or more electromechanical solenoid-valves that control the flow of product and the venting process.

A number of preferred embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings.

Brief description of the invention

Figure 1 shows a cross-sectional view of one potential implementation of the invention, suitable for use with a single keg.

Figure 2 shows a second potential implementation for two or more kegs.

Figure 3 is a bubble-diagram describing an implementation of the FSM.

Page 2 Detailed des.ription of the invention Figure 1 is a diagram showing how the product flows from the keg (3) through pipework to a chamber (14) which is shown as a cross-section. The product is propelled by the pressure of the gas in the container (1). The gas flows into the keg (3) via a keg-connector (2). The product, with some gas dissolved in it, exits the keg (3) through another part of the same keg-connector (2) and through pipework to the chamber (14).

The product enters the chamber through an input port (4) which is approximately at the midpoint of the height of the chamber. The exact positioning of the input port (4) will be varied according to the needs of the particular product and gas in the installation. For clarity in this example implementation, the input port is shown at the midpoint of the chamber.

A float (5) contains a means of activating two or more sensors (6, 7, 8). In the example in figure 1, three sensors (6, 7, 8) are shown. The float may contain a magnet (16) (when using Hall-effect or reed-relay sensors), a mirror (when using optical/infra-red sensors) or may contain part of another similar electronic sensing system. A number of these sensor systems are in common use and will be familiar to those skilled in the art. The sensors (6, 7, 8) and float are chosen such that if the vertical position of the float (5) is close to that of a sensor, the sensor is activated and sends a signal to the electronic circuit (12). This signal will typically be low-impedance when the float is close to a given sensor and a high impedance when the float is some distance from that sensor.

Note that the height of liquid may be detected either by two or more individual sensors on or near the chamber, or by a continuous sensor system employing an analogue float-height transducer. The implementation illustrated in figure 1 uses three discrete sensors (6, 7, 8).

The vertical position of the float will vary according to the amount of liquid in the chamber. The position of the middle sensor (6) is chosen to be at the optimum height for liquid in the chamber. In a typical implementation this might represent approximately 0.3 litres of liquid. If the liquid is at the optimum height then the electronic circuit is in its normal mode where liquid is permitted to flow out of the chamber through the open output solenoid-valve (9) and the vent solenoid-valve (10) is closed. The product is then available at the point-of-service (11).

If there is excess foaming in the chamber, then the ratio of liquid to gas will reduce and the float will move downwards. If the float loses contact with the middle sensor (6) then the electronic circuit will detect the change in state of the middle sensor (6) and will open the vent solenoid-valve (10). This will release the gas from the upper part of the chamber to a waste area (13). As the gas is removed it will be replaced by more liquid from the input port (4). The float will rise until it returns to the optimum point. When it reaches the optimum point it will be in line with the middle sensor (6) and will therefore trigger the electronic circuit (12) to close the vent solenoid-valve (10). By this method, the float (5) is kept at or below the optimum point.

If the ratio of liquid to gas varies the other way the float will rise up and will lose contact with the nuiddle sensor (6). This will cause the same response in the electronic circuit so that the vent solenoid-valve (10) is opened. The float will continue to rise until is in line with the upper sensor (7). This triaCers the electronic circuit to close the vent solenoid-valve (10). By this method the float is maintained in a position between the middle sensor (6) and the upper sensor Page 3 (7). In this implementation the upper sensor (7) is quite close to the middle sensor (6), thereby ensuring that th float never moves very far fTom the optimum position.

Eventually the keg will become empty when the product is exhausted. This will cause gas to flow from the container (1) through the keg (3) and to the chamber input port (4). The last of the liquid will exit the chamber through the exit solenoid-valve (9). This will cause the float to fall below the middle sensor (6). The vent solenoid-valve (10) will open briefly but this cannot cause the float to rise because the liquid is exhausted. The float will continue to fall until it is in line with the lower sensor (8). This will trigger the electronic-circuit to close the output solenoid valve (9). This is desirable in order to stop the potential rapid and wasteful flow of gas out to the point-of-service (11). Optionally, the electronic-circuit can issue a warning to the staff by means of an audible tone, flashing fight, or other similar means.

In the single-keg implementation described above, and shown in figure 1, manual intervention is now required to change the keg. Insertion of the keg-connector (2) into the new keg (3) will cause an inrush of gas and movement of liquid through the chamber input port (4). In most cases this will be sufficient to raise the float away from the lower sensor (8) thereby returning the electronic-circuit to normal operation. If the inrush of liquid is insufficient to raise the float away from the lower sensor then a vent switch (15) is provided to manually override the electronic circuit. Pressing the vent switch (15) causes the vent solenoid-valve (10) to open, thereby raising the float away from the lower sensor (9).

To aid in understanding the description above, figure 3 is a bubblediagram of the logic of the Finite State Machine (FSM). This shows how the signals from the three sensors (6, 7, 8 in figure 1) are used as inputs to the FSM. The FSM has two outputs, which drive the output solenoid-valve (9) and the vent solenoid-valve (10). The FSM is part of the electronic circuit which may also contain some simple power circuits and optional status indicator lights. The FSM can be implemented in a number of ways, familiar to those skilled in the art, including a microprocessor, Progranimable-Array-Logic (PAL), Transistor-Transistor Logic (TTL) or similar.

A further refinement of the invention is now described.This refinement simplifies the keg-change procedure and reduces the amount of manual intervention..

0 In figure 2, an implementation of the invention is shown where a plurality of kegs is connected to the chamber. For clarity, figure 2 shows 2 kegs only, but the invention is readily scaleable to three, four or any required quantity of kegs. The the input port (4) previously described in figure 1 is replaced in figure 2 by two extra solenoid- valves (23) and (24) similar to those used for the output (9) and vent (10). Product is supplied from one of the two attached kegs. When the electronic circuit detects that the product in that keg is exhausted, it closes the solenoid-valve for that input port and opens the other. Only when the second keg is exhausted will the electronic-circuit need to close the output solenoid-valve (9). A small extension to the logic of figure 3 is required to drive the enhanced configuration shown in figure 2.

0 One other refinement of the invention is to use the output solenoidvalve (9) to control the flow of liquid at the point-of- service (11). Instead of a conventional manually-operated valve at the point-of-service (11), a switch can be provided to allow staff to open and close the output solenoid-valve when liquid needs to be dispensed. This will also have use in self-service applications.

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Claims (1)

1. Claims

   1. A system for controlling the foaming behaviour of liquids for human consumption, said system containing a chamber with means for electronic detection of the height of liquid in the chamber. A system as claimed in claim 1, that releases liquid and gas by electronically opening and closing valves at lower and upper positions respectively.

   3. A system as claimed in claims 1 and 2 that detects when the supply of liquid is exhausted and closes both upper and lower valves.

   4. A system as claimed in claims 1 and 2 that detects when the supply of liquid is exhausted and switches to another source of liquid.

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