GB2145249A - Liquid supply line control circuitry - Google Patents

Abstract

A beer supply circuit comprising beer kegs 1,2 pressurised from a CO2 cylinder 12 incorporates control circuitry for maintaining the pressure in the kegs. This circuitry comprises a pressure switch 16 which controls solenoid operated valve 13. When the pressure in the kegs 1,2 falls, the switch 16 operates to open the valve 13 to permit CO2 flow from cylinder 12 to kegs 1,2 but to prevent further flow when the pressure has once again reached a satisfactory level. A timer may be provided operative to cause a control signal to issue should the solenoid be on for too long a time thus indicating either an empty cylinder or a fault such as a leak. <IMAGE>

Description

SPECIFICATION Liquid supply line control circuitry The present invention relates to control circuitry, particularly, but not exclusively, for pressurised beverage lines.

At the present time many beverage lines, such as beer lines, are pressurised usually by a source of carbon dioxide. This source of carbon dioxide is connected by pressure fluid lines through appropriate pressure fluid valve means to one or more beer kegs. These lines are generally connected to the upper parts of the kegs and outlet beverage lines lead, generally from the lower parts of the keg to respective taps situated at appropriate locations on the bar. If pressurisation is uncontrolled, the beer becomes over pressurised with the carbon dioxide and absorbs too much carbon dioxide.

When the beer is subsequently dispensed, this over absorption of the carbon dioxide is released from solution causing unacceptable frothing which interferes with delivery.

According to the present invention, there is provided control circuitry for maintaining the pressure in a liquid container above a certain level comprising indicator means for giving an indication of the pressure in the containers, and means for controlling the flow of gas from a supply to the container in response to a signal from the indicator means.

In a preferred form of the invention in which beer kegs are pressurised from a CO2 cylinder, the indicator means comprises a pressure operated switch and the means for controlling the flow of gas comprises a solenoid operated valve. When the pressure in the line from the cylinder to the kegs falls below a certain threshold value, the pressure operated switch energises the solenoid to open the valve and then deenergises the solenoid to close the valve when a certain upper threshold value is obtained. If desired, a timer can be provided to issue a control signal should the solenoid be energised for longer than a certain predetermined period thus indicating the presence of a fault such as a leak or an empty carbon dioxide cylinder. The current operating mode is advantageously indicated by illuminating one or more indicator lights. These may be light emitting diodes or neons.

In order that the invention may be more clearly understood, one embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a fluid circuit diagram for a beer supply installation, Figure 2 is an electrical circuit diagram for the installation of Figure 1, and Figure 3 is a diagram corresponding to Figure 2 and showing the relative locations of the main elements of the electrical circuit.

Referring to Figure 1, the installations comprises two beer kegs 1 and 2. Connected to the lower parts of the kegs are respective beer lines 3 and 4 supplying respective taps 5 and 6 which are fixed at appropriate positions on the bar. Two carbon dioxide (CO2) supply lines 7 and 8 lead from the upper parts of respective kegs 1 and 2 via respective line pressure indicator devices 9 and 10 and a common carbon dioxide supply line 11 to a carbon dioxide supply cyliner 12. A solenoid operated fluid control valve 13 is disposed in the common supply line 11. A further line pressure indicating device 17 is connected to the common line. A pressure switch 16 is connected to the common line 11. Devices 9 and 10 are capable of measuring pressures up to 30 psi and device 17 up to what ever pressure is required.

However, recommended maximum pressures for 9, 10 and 17 are 15 psi, 15psi and 30 psi respectively. All of this equipment except for the taps 5 and 6 and a section of the lines 3 and 4 running to the taps would generally be disposed in the cellar.

The electrical equipment for operating the circuit of Figure 1 comprises a transformer 20, for transforming down from the mains 19, feeding an electrical control circuit comprising a timer 21 with associated timer reset button 21A, pressure switch 22, a solenoid 23 for operating solenoid valve 13 and indicator means 24. The indicator means 24 comprises green, red and amber light emitting diodes 25, 26 and 27 to indicate the particular operational mode of the equipment and a further green light emitting diode 28 to indicate when the prime button, referenced 29 in Figure 3 is operated. A fuse 30 is disposed in the live line from the mains supply. An ON/OFF switch 31 is provided. Of this electrical equipment that contained within the box A in Figure 3 is disposed at the bar whereas that contained within the box B in Figure 3 is disposed in the cellar.The equipment of both boxes A and B is connected by means of a four core cable C. Boxes shown in dotted outline 32 and 33 represent connector strips.

The above described equipment effectively has four modes of operation, two off modes and two on modes. In the first off mode, the power is off.

All of the indicator LED's 25 to 27 are off and the solenoid operated valve 13 is closed, the solenoid 23 being de-energised. In the second off mode the power is on,that is the ON/OFF switch is closed LED 25 is on and LEDs 26 to 27 are off, but the solenoid operated valve 13 is closed. The solenoid 23 again being de-energised. In both these modes with valve 13 closed, no carbon dioxide flows from the cylinder 12 to the kegs 1 and 2.

In the first on mode, if the pressure downstream of the solenoid valve 13 falls to a certain threshold level (say 25 psi) necessary to operate the pressure switch 16, the pressure switch 16 closes to complete the circuit to the solenoid 23, energise the solenoid and open the valve 13 to permit carbon dioxide to flow from the cylinder 12 to the kegs 1 and 2 to restore the pressure in them. In this mode LEDs 25 and 26 are on, but LED's 27 and 28 are off.

Carbon dioxide continues to flow until the pressure in line 11 reaches the threshold value (say 30 psi) necessary to switch the pressure switch off deenergise the solenoid 23 and close valve 13. This on mode is the normal operating mode necessary to maintain pressure in the kegs 1 and 2.

The second on mode is provided to cater for a fault in the system. Under normal circumstances opening the valve 13 for a predetermined time will be sufficient to restore pressure in the kegs. If this period is timed by the timer 21 and valve 13 is still open a fault is indicated. This may be a leak in the system or a empty cylinder. Under those circumstances after the timed period has elapsed, the timer produces a control signal to operate the solenoid to close valve 13 and to light LED 27 in addition to LED's 25 and 26. To reset to the first mode press reset button 21A The prime button 29 may be operated to open the solenoid valve directly to connect the CO2 cylinder to the kegs. When operated, LED 28 (green) will light up.

It will be appreciated that with the above described embodiment pressure inthe beer lines may be maintained without undue absorption and therefore loss of carbon dioxide and leaks or the requirement for a replacement carbon dioxide cylinder may be reliably and simply indicated. Other advantages are the indication of an accidentally closed CO2 cylinder, of faulty reducing valves, and of faulty cylinder connections. Pressure in the system is continuously monitored and pressure to the kegs is restricted. Individual product lines may be separately regulated. By providing the CO2 supply control switch at the bar, the need for the bar operator to go to the cellar to switch on or off the CO2 is obviated. These advantages provide for more reliable operation reduced maintenance and lower costs. Although carbon dioxide has been referred to in the above embodiment other gases such as air and nitrogen may equally well be used.

Claims (11)

1. Control circuitry for maintaining the pressure in a liquid container above a certain level comprising indicator means for giving an indication of the pressure in the containers, and means for controlling the flow of gas from a supply to the container in response to a signal from the indicator means.

2. Control circuitry as claimed in claim 1, in which the indicator means comprises a pressure operated switch.

3. Control circuitry as claimed in claim 1 or 2, in which the means for controlling the flow of gas comprises a solenoid operated valve.

4. Control circuitry as claimed in claim 3, when appendant to claim 2, in which when the pressure in the supply line to the container falls below a certain threshold value, the pressure operated switch energises the solenoid to open the valve and then de-energises the solenoid to close the valve when a certain upper threshold valve is obtained.

5. Control circuitry as claimed in claim 3 or 4, in which a timer is provided to issue a control signal should the solenoid be energised for longer than a certain predetermined period.

6. Control circuitry as claimed in any preceding claim, in which means are provided for indicating the current operating mode of the circuitry.

7. Control circuitry as claimed in claim 6, in which the means for indicating the current operating mode are visual.

8. Control circuitry as claimed in claim 7, in which the visual means for indicating the current operating comprises one or more indicator lights.

9. Control circuitry as claimed in claim 8, in which the indicator lights are light emitting diodes or neons.

10. Control circuitry for maintaining the pressure in a liquid container substantially as hereinbefore described with reference to the accompanying drawings.

11. A beverage supply circuit comprising control circuitry as claimed in any preceding claim.