TECHNICAL FIELD

The present invention relates to the control of pressurising and de-gassing of beverage storage containers. BACKGROUND ART

It is well known in the field of beverage dispensing to use carbon dioxide under pressure to force the beverage out of -its storage container and through the dispensing system. It has been found, however, with such systems that if the beverage is maintained under pressure during periods of non-use, such as overnight, then the head-gas tends to be absorbed into the beverage liquid resulting in poor dispensing of the beverage and possible distortion of the beverage taste characteristics. To overcome this problem, de-gassing of the system is undertaken. This is a time-consuming and delicate process requiring disconnecting of gas

supplies, venting of containers and reconnection when the system is required for normal use. The process is even more complicated with multiple dispensing systems.

The present invention seeks to overcome or at least ameliorate the disadvantages associated with the prior art de-gassing methods by provision of an apparatus which enables simple quick and effective de-gassing of a beverage dispensing system. DISCLOSURE OF THE INVENTION

According to the invention there is provided a control system for controlling the pressurising and de-gassing of one or more beverage storage containers comprising: a three-way valve having a first, second and third port, and operable in response to a control signal to provided selective communication between said first port and either said second or third port; said first port being connected to said beverage container; said second port being connected to a source of pressurised fluid and said third port having means to provide a vent to atmosphere.

Preferably, the third port is provided with a pressure-controlled valve such that the third port is vented to atmosphere until a predetermined minimum pressure is reached within the beverage container. The valve then closes the third port to maintain the pressure within the beverage container at the predetermined value.

BRIEF DESCRIPTION OF DRAWINGS

A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a pictorial representation of the control system according to the invention;

Figure 2 is a pictorial representation of the cylinder supply lead assembly;

Figure 3 is a pictorial representation of the manifold header assembly according to the invention;

Figure 4 is a pictorial representation of the electrical control unit used with the control system of Figure 1;

Figure 5 is a schematic circuit diagram of the electrical control circuit of Figure 4; and

Figure 6 is a diagrammatical representation of the gas circuit according to the invention. BEST MODE OF CARRYING OUT THE INVENTION

Referring to the drawings, the gas control unit assembly comprises a three-way solenoid valve 5, having a coil 6 which operates the solenoid. The valve 5 has three ports 7, 8 and 9, with port 7 being selectively coupled to port 8 or 9 dependent on the activation of the solenoid coil 6. Port 8 is coupled via a pressure- controlled valve 10 to atmosphere, while port 9 is coupled to a pressurized source of CO via a non-return valve 11 and pressure reducing valve 12. The pressure reducing valve 12 is further provided with a

pressure gauge 13 and safety relief valve 14. The non-return valve 11 prevents reverse flow of gas from the beverage container (and in specific circumstances the beverage themselves) . The pressure reducing valve 12 reduces the inlet pressure to a desirable working range while the safety relief valve 14 protects the beverage containers from over pressure. The pressure reducing valve 12 is connected to the source of pressurised CO via a quick-connect self-sealing coupling 39. Port 7 is coupled to a beverage container 36 via a quick-connect coupling 40 and a conventional hose coupling 41.

The pressure-controlled valve 10 comprises a pressure sensing switch 44 which is coupled to the port 8 by a transfer tube 45 which connects to the inlet 46 of a tee-piece 47. The outlet 48 of the tee-piece is coupled to a solenoid operated valve 49 which in turn is vented to atmosphere via restrictor valve 50.

Referring to Figure 2, the cylinder supply lead assembly for connecting the CO pressurised source to the manifold header assembly 20 is shown pictorially. This assembly comprises a 240 VAC heater 15 coupled to the CO gas cylinder via a conventional gas coupling 16. The gas then passes through a pressure reducing valve 17 and to a coupling 18 and quick connector self-sealing adapter 19 to the manifold header assembly. The pressure reducing valve 17 is provided with pressure gauge 43 for monitoring

pressure supply. The heater 15, heats the gas prior to entry into the pressure reducing valve 17 to prevent freezing of this valve during high flow conditions.

Referring to Figure 3, the manifold header assembly 20 comprises a number of header blocks 21 interconnected by manifold pipes 22. Each header block 21 is provided with a quick-connect self-sealing coupling 23 for connection to a respective gas control unit 4. One end of the header assembly 20 is provided with a non-return valve 24 communicating with the header blocks 21. This non-return valve 24 is coupled, in use, to a bulk source of CO 2, as will be described later. The other end of the header assembly is provided with a further inlet port 25 coupled to a non-return valve 26 which is connected to supply lead assembly via a quick connect self-sealing coupling 27. The non-return valves 24 and 26 serve to prevent reverse flow conditions occurring when either of the main or back-up gas supplies becomes depleted. The header assembly is further provided with a safety relief valve 28 and pressure gauge 29 to ensure the working pressure is not exceeded.

The electrical control unit (ECU), as shown in Figure 4, comprises a component box 30 and a number of SPST switches 31 corresponding to the number of gas control units 4 to be controlled. A wiring harness 32 carries control wires to each of the solenoid control coils 6 associated with each gas control unit 4. The control wires are connected to each control coil 6 by a

sealed coil connector 33. Each coil connector 33 is also provided with a lamp 35 to indicate whether it is in an operative condition. As shown in Figure 5, the mains voltage to the control unit 4 is reduced to a safe 24 VAC operating voltage.

The operation of the system will now be described with reference to Figure 6 of the drawings which shows a diagrammatic representation of the gas circuit. Each gas control unit 4 is connected to a respective outlet 23 of the manifold header assembly 20 and in turn connects to a respective beverage container 36. The header assembly 20 is connected to a bulk CO supply 37 and a back-up CO cylinder supply 38. In normal use the header assembly 20 feeds CO to the beverage container 36 via the gas control unit 4 which has its three-way valves switched so that ports 7 and 9 are in communication. When the system is to be de-gassed, the appropriate switch of the ECU is operated and the solenoid coil 6 of the associated control unit 4 is energized causing the gas supply to be isolated from the beverage container 36 and the port 8 to be in communication with port 7 resulting in the beverage container 36 being vented to atmosphere via pressure- controlled valve 10.

This results in release of head-gas and adsorbed gas from the container until a preset blanket pressure is reached. Once the blanket pressure is reached the pressure switch 44 is activated causing solenoid valve

49 to close and stop further venting to atmosphere via restrictor valve 50. This serves to maintain a blanket of CO over the beverage and prevents outside contaminants entering the beverage container. The blanket pressure is preferably selected to correspond to the normal storage pressure used by the beverage manufacturer. In the case of beer this is typically 160 kpa.

The three-way valves 5 are normally in a position of connecting ports 7 and 9, so that in the event of a power failure, gas will be provided to the beverage containers and the dispensing system will be operable. The restrictor valve 50 regulates the venting to prevent discharge under pressure of the beverage.

It will be appreciated that further embodiments of the invention are possible without departing from the spirit or scope of the invention described.