GB2367128A

GB2367128A - Drinks dispenser with fluid resistance sensor

Info

Publication number: GB2367128A
Application number: GB0014364A
Authority: GB
Inventors: John Rodgers
Original assignee: Booth Dispensers Ltd
Current assignee: Booth Dispensers Ltd
Priority date: 2000-06-14
Filing date: 2000-06-14
Publication date: 2002-03-27
Anticipated expiration: 2020-06-14
Also published as: GB2367128B; GB0014364D0

Abstract

Syrup from supply (12) passes through valve (16) past electrical resistance sensor (20). Two separated electrodes penetrate the pipe walls and a differential is applied across them. A steady fluid flow is measured as a constant resistance between the electrodes. If bubbles are present in the fluid indicating the fluid is running out, then the resistance monitored rises and an alarm may be given or valve (14) may be activated to provide syrup from second supply (10). The resistance of the syrup supply is monitored until it is substantially constant when a full satisfactory flow is established. A control circuit then adds a small value to that resistance to set a trigger value for switching supplies.

Description

Drinks Dispenser The present invention relates to a method of monitoring fluid and fluid control apparatus and is particularly, although not exclusively, related to monitoring syrup in a drink.

In a known apparatus for dispensing syrup for inclusion in a drink, an electrical resistance bridge is placed along the fluid flow path. Whilst the syrup flows past, or remains across the bridge a low resistance is detected.

When the syrup runs out, there is a large increase in the resistance of the bridge and a signal can be given. That signal may comprise switching to a new supply source or giving an alarm that a new source is required.

The bridges that are provided cover a range of syrups each of which has a different resistance. Accordingly the level of resistance at which an alarm is to be given must be set for when air is present in the most resistive syrup. Furthermore, the resistance of a particular type of syrup can vary from batch to batch. Consequently the alarm level is set for the highest resistance syrup and indeed the highest likely batch in that syrup.

Consequently the alarm will not be triggered for most syrups passing the bridge until there is a considerable volume of air across the bridge. By that time many substandard drinks each containing successively less syrup will have been dispensed.

In known syrup dispense systems when syrup from one supply runs out the pump conveying syrup to the dispense pulls a vacuum and it is this pressure that causes valves to open

and close to alter the supply source. This system though ensures that considerable dumping or the dispensing of a great many substandard drinks takes place before a satisfactory drink containing syrup from the new supply is dispensed.

According to one aspect of the present invention a method of monitoring fluid comprises monitoring an electrical value of the fluid and noting when there is a change in that value beyond a set value with the method including changing the set value.

The method may comprise changing the set value

automatically or, alternatively or additionally, manually.

I The method may comprise monitoring fluid in a supply tube and the method may comprise monitoring that fluid either when it is stationary or when it flows or both.

The method may comprise continually or repeatedly monitoring the fluid.

The method may comprise resetting the set value when a supply source of the fluid is changed.

The method may comprise permitting the set value to move in one direction and noting when there has been a relatively small move in the value in the other direction.

The method may comprise the fluid supply source being altered upon noting the change in value, for instance by actuation of at least one valve such as electronically

controlled valve and the method may comprise causing one valve to close and another to open.

The method may comprise fluid being dumped upon noting when there has been a change in the value beyond the set value.

The method may comprise monitoring the resistance of the fluid and the method may comprise noting when there has been an increase in the resistance.

The method may comprise separately monitoring two fluid supplies each of which is capable of supplying a common flow region.

The method may comprise monitoring the electrical value of the fluid along a length of supply of the fluid and that length may be less than 100 mm or less than 60 mm and is preferably in the region of 40 mm and the length may be more than 10 mm or more than 25 mm.

The cross sectional area of the fluid flow that is monitored may be less than 50 mm2, or less than 40 mm2 and

in the region of 28 mm2 and the area being monitored may be more than 10 mm2 or more than 20 mm2 The method may comprise monitoring at least part of the fluid to be supplied to a drink. The method may comprise monitoring at least part of a drink for use in a vending machine or in a staffed area.

The method may comprise giving an alarm or other signal

when there has been a change in the value beyond a set value. According to another aspect of the present invention fluid control apparatus comprises electrical monitoring means arranged to monitor an electrical value of a fluid and means for noting a change in the value being monitored beyond a set value and means for altering the set value.

The present invention also includes fluid control apparatus including means to effect any aspect of the method of monitoring the fluid as herein referred to.

The present invention includes any combination of the herein referred to features or limitations.

The present invention can be carried into practice in various ways but several embodiments will now be described, by way of example, and with reference to the accompanying drawings, in which: Figure 1 is a schematic view showing the flow diagram of a syrup supply station, and Figure 2 is a graph illustrating the operation of a resistance bridge shown in Figure 1.

As shown in Figure 1, two alternative supplies 10 and 12 of the same syrup to be used in a drink are shown. In the position shown a solenoid valve 14 that controls flow from the supply 10 is closed and a solenoid valve 16 for the other supply 12 is open thus ensuring syrup from the supply 12 is dispensed. A pump 18 pulls the syrup from

the relevant supply with that syrup passing a resistance sensor bridge 20. An indicator 22 which may, for instance comprise a light, shows that the reserve supply 12 is in use and that the supply will need topping up or replacing.

The bridge 20 measures the resistance of fluid in a 6 mm internal diameter plastic pipe. The monitoring may be continuous or at short intervals. Two electrodes penetrate the pipe walls at a distance of 40 mm apart and a differential is applied across the electrodes and the resistance-between the electrodes is monitored by a control circuit 24 that includes a pcb.

When the resistance between the electrodes rises above a

I predetermined value such as when air is present in the syrup across the bridge an alarm will be given or the supply will be changed over.

With the present invention though the level of resistance required to give the alarm or cause the changeover can be varied.

In one embodiment, when a new syrup supply of the same syrup as previously dispensed is connected, or when a different syrup is connected, the resistance of the bridge will be monitored until it is substantially constant.

This is when full satisfactory flow has been established.

Then the control circuit will add a small value to that resistance to set a trigger or alarm value. The resistance across the bridge will then be monitored until that trigger value is reached or exceeded.

Figure 2 illustrates the different trigger values 26 and 28 that have been set for slightly different batches of the same syrup. The values 26A and 28A show the normal resistance that is detected when full flow of the syrup occurs. The value 30 is the trigger set for another type of syrup with the value 30A being the normal operating resistance for that syrup during full flow.

It can be seen from Figure 2 that, for each syrup, an extremely small increase in resistance activates the trigger. Such a small increase may be occasioned by a small bubble of air being detected in the pipe across the bridge.

When a trigger is activated a signal may be set to close the valve 14 and open the valve 16, for instance. In a vending operation upon activation of the trigger, the machine may automatically dump the next five drinks, for instance, if that is what it takes to ensure syrup from the new supply is satisfactory at the dispense region.

Alternatively dumping may continue until the bridge senses that the new syrup flow is at a satisfactory or minimum resistance value, with perhaps dumping continuing for a short time afterwards. The same mode of operation may be used in a staffed bar by manual dumping or, alternatively or additionally an alarm may be given by the trigger to alert the operator to the fact that syrup supply is no longer satisfactory (in which case manual dumping can occur) or, alternatively or additionally to alert the operator that a new supply requires to be connected or switched.

As the present bridge can be made so sensitive it may be that syrup can continue to be dispensed without any significant fall in the quality of the drink being discharged and without any dumping. That is because the syrup does not tend to flow fully and then completely stop. Rather small bubbles that reduce the resistance slightly are supplied the resistance gradually increasing as the bubbles increase as the syrup runs out.

It is possible that the control circuit can have a manual or automatic switch that is activated each time a new syrup is supplied. Alternatively or additionally the resistance can be monitored after a trigger has been activated to watch for the resistance reducing and reaching a steady state with the new syrup supply with a new trigger value being set. Alternatively or additionally the resistance can be monitored with the control circuit watching for any relatively small increase in resistance but with that effective trigger value changing and reducing.

Figure 1 shows, in chain lines, possible alternative mountings for sensor bridges 20A and 2 OB. Monitoring at these locations allows the valves to be switched without substandard syrup from that supply being able to reach the dispense. Thus the valve 14 would be closed when the resistance in the bridge 20A rose above the trigger value before the fluid section that activated the trigger reached the valve 14. In this embodiment the trigger may cause the valve 16 to open and the bridge 20B and the associated control circuitry to be activated.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so-disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s). The invention extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS 1. A method of monitoring fluid comprising monitoring an electrical value of the fluid and noting when there is a change in that value beyond a set value, the method also including changing the set value.
2. A method as claimed in Claim 1 comprising changing the set value automatically.
3. A method as claimed in Claim 1 or 2 comprising changing the set value manually.
4. A method as claimed in any preceding claim comprising monitoring fluid in a supply tube.
5. A method as claimed in Claim 4 comprising monitoring the fluid in the supply tube when it is stationary.
6. A method as claimed in Claim 4 or 5 comprising monitoring the fluid in the supply tube when the fluid is flowing.
7. A method as claimed in any preceding claim comprising continually monitoring the fluid.
8. A method as claimed in any preceding claim comprising repeatedly monitoring the fluid.
9. A method as claimed in any preceding claim comprising resetting the set value when the supply source of the fluid is changed.
10. A method as claimed in any preceding claim comprising permitting the set value to move in one direction and noting when there has been a relatively small move in the value in the other direction.
11. A method as claimed in any preceding claim comprising the fluid supply source being altered upon noting the change in value.
12. A method as claimed in Claim 11 comprising altering the fluid supply source by actuation of at least one valve.
13. A method as claimed in any preceding claim comprising fluid being dumped upon noting when there has been a change in the value beyond the set value.
14. A method as claimed in any preceding claim comprising monitoring the electrical resistance of the fluid.
15. A method as claimed in Claim 14 comprising noting when there has been an increase in the electrical resistance of the fluid.
16. A method as claimed in any preceding claim comprising separately monitoring two fluid supplies each of which is capable of supplying a common flow region.
17. A method as claimed in any preceding claim comprising monitoring the electrical value of the fluid along a length of supply of the fluid.
18. A method as claimed in Claim 17 comprising monitoring the electrical value of the fluid along a length in the region of 40 mm of supply of the fluid.
19. A method as claimed in any preceding claim comprising the cross sectional area of the fluid flow that is monitored being in the region of 28 mm2.
20. A method as claimed in any preceding claim comprising monitoring at least part of fluid to be supplied to a drink.
21. A method as claimed in any preceding claim comprising giving a signal when there has been a change in the value beyond a set value.
22. A method of monitoring fluid substantially as herein described with reference to, and as shown in any of Figures 1 or 2.
23. Control apparatus comprising electrical monitoring means arranged to monitor an electrical value of a fluid and means for noting a change in the value being monitored beyond a set value and means for altering the set value.
24. Fluid control apparatus substantially as herein described with reference to, and as shown in any of the accompanying drawings.
25. Apparatus as claimed in Claim 22 or 23 when used in the method of any of Claims 1 to 22.