GB2247920A

GB2247920A - A pump controller

Info

Publication number: GB2247920A
Application number: GB9018786A
Authority: GB
Inventors: Sammy James Engineer; Stephen Charles Lord
Original assignee: Whitbread and Co Ltd
Current assignee: Whitbread and Co Ltd
Priority date: 1990-08-28
Filing date: 1990-08-28
Publication date: 1992-03-18
Anticipated expiration: 2010-08-28
Also published as: GB9018786D0; GB2247920B

Abstract

A fluid pump controller, more particularly for dispensing beer from a store to a bar, comprising a pump (1) with an impeller (2), an inlet (3) for the fluid which flows via tube (4) to an outlet (5) and a magnetic float (9) which closes a seating (7) between the inlet (3) and the outlet (5). A flow sensing means (SW1) cooperates with the magnetic float (9) to control the fluid flow from the pump to the outlet (5) with minimum pressure drop in the fluid being pumped. <IMAGE>

Description

A PUMP CONTROLLER This invention relates to a pump controller more particularly, but not exclusively to a pump for dispensing beer from a store to a bar.

It is known to sense the presence of flow in a pump using a float incorporating a magnet via a reed switch.

An aim of the present invention is to incorporate a flow sensor in the pump with minimum pressure drop in the supply line.

According to the present invention there is provided a fluid pump controller comprising a pump with an inlet and an outlet, a magnetic float incorporating a non-return valve to close a seating between the inlet and outlet and a flow sensing means co-operating with the magnetic float to control fluid flow from the pump to the outlet with minimum pressure drop in the fluid being pumped.

Preferably, the flow sensing means and pressure sensing means utilise a power supply providing a regulated 5 volt d.c. from a series connection to a live wire of a motor. In the preferred configuration this is achieved by utilising the forward voltage characteristics of diodes.

Conveniently, the power supply to the sensing means is suitable for use with CMOS logic at all motor speeds.

In a preferred construction the power supply drives an electronic circuit with a microcontroller to reduce component count.

The microcontroller conveniently incorporates inputs and outputs to read a pressure sensor and pressure set potentiometer. The flow switch is preferably in the form of a reed switch which is read by the microprocessor via a digital input.

An embodiment of the pump controller according to the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic view of a pump controller; and Figure 2 is a circuit diagram of an electronic control layout.

Figure 3 is an enlarged fragmentary detail of the float in its non-flow position.

The electric pump controller comprises a pump head 1 with a pump impeller 2. Fluid flows in an inlet 3 via a tube 4 to an outlet 5. The tube 4 is flanged at one end 6 and connected to a seating 7 by a screwthreaded collar 8 which secures the tube flange to the pump head 1.

Slidably located in the tube 4 is a float 9 which is integral with a valve member 10 and incorporates a magnet 11. A reed switch SW1 is located near the lower end of the tube 4 while a pressure switch 12 incorporating a magnet 13 is mounted near the upper end of tube 4. A pressure sensitive diaphragm operates a Hall effect I.C. 14 forming a pressure sensor VSI, connected to an electronic circuit illustrated in Figure 2 which comprises a motor 15 connected via triac 16 to a (PSU) power supply unit 17 which is fed with current at 110 volts AC. The output from the PSU provides a regulated 5 volt d.c. to a microcontroller 18 incorporating A/D input. An output from the microcontroller is used to drive the opto-triac 19 which in turn drives the motor control triac 16. AC phase information is provided to the microcontroller via wire 20.By this means the microcontroller may control the power delivered to the motor.

The microcontroller 18 operates the pressure sensor VSI the pressure set VS2 and the flow switch SW1.

The microcontroller 18 offers the option of an enhanced specification enabling the pump controller to be in communication with monitoring equipment and allows for simple programming, via a single control.

In operation a tap (not shown) to dispense a beverage, for example, beer is opened the motor 15 runs normally, i.e., the motor speed is varied to maintain a constant pressure in the tube 4. As the pressure in tube 4 decreases and the float 9 rises the motor 15 is started and a lower seal 20 seats against the lower end of seating 7, allowing the flow of beverage in tube 4. When the tap is closed the pressure in tube 4 increases and the float 9 falls seating against the ring 21 to seal the valve and preventing flow of beverage in the tube 4. A 1 second pulse at the full running speed of the motor 15 is applied to repressurise the tube 4 and the motor is then stopped. In the event of the beer line emptying the pressure decreases and the float 9 falls, the motor is disabled after a pre determined time. To prime the line with the beverage to be pumped a button is pushed to operate the motor, once the line is primed the pressure increases, float full and the pump is stopped.

It will be apparent that the beverage e.g. beer being pumped is controlled by the flow sensing means pressure sensing means co-operating with the magnetic float 9 to control the beverage flow from the pump to the outlet (tap) with a minimum pressure drop in the beverage being pumped.

Claims

CLAIMS:

1. A fluid pump controller comprising a pump with an inlet and an outlet, a magnetic float incorporating a non-return valve to close a seating between the inlet and outlet and a flow sensing means co-operating with the magnetic float to control fluid flow from the pump to the outlet with minimum pressure drop in the fluid being pumped.

2. A fluid pump controller, as claimed in Claim 1, wherein the flow sensing means and pressure sensing means utilise a power supply providing a regulated 5 volt d.c.

from a series connection to a live wire of an AC motor.

3. A fluid pump controller as claimed in Claim 1 or 2, wherein the sensing means is suitable for use with CMOS logic at all motor speeds.

4. A fluid pump controller as claimed in Claim 2 or 3, wherein the power supply drives an electronic circuit with a microcontroller to reduce component count.

5. A fluid pump controller as claimed in Claim 4, wherein the microcontroller incorporates inputs and outputs to read a pressure sensor, a pressure set and a flow switch.

6. A fluid pump controller as claimed in Claim 5, wherein the pressure sensor uses a Hall effect I.C.

7. A fluid pump controller as claimed in Claim 5 or 6, wherein the flow switch is in the form of a reed switch.

8. A fluid pump controller as claimed in any preceding claim, wherein the non-return valve seats in a seating connected adjacent the head of the pump.

9. A fluid pump controller substantially as herein described, with reference to the accompanying drawings.