GB2566028A

GB2566028A - Improvements in water control systems

Info

Publication number: GB2566028A
Application number: GB1713873.6A
Authority: GB
Inventors: Mollinari Maurizio; Meacock David
Original assignee: Cistermiser Ltd
Current assignee: Cistermiser Ltd
Priority date: 2017-08-30
Filing date: 2017-08-30
Publication date: 2019-03-06
Anticipated expiration: 2037-08-30
Also published as: GB2566028B; GB201713873D0

Abstract

A control system is provided for a water storage tank 10. Water is supplied to the tank 10 from a mains supply line 11 via an inlet valve assembly 12. The inlet valve assembly 12 is controlled by a control unit 14 in response to signals received from a sensor 13. The inlet valve assembly 12 is in the form of a motor driven valve mechanism. The control unit 14 is designed to operate the inlet valve assembly 12 to control the flow of water into the tank whilst receiving feedback from operation of the motor drive mechanism. The control means may be arranged to be operable to compare the current profile derived from the feedback with an expected current profile in order to determine the performance of the inlet valve assembly. If the derived current profile from the feedback does not match the expected current profile, the control means may be arranged to issue a warning indicating a fault.

Description

Improvements in water control systems

This invention relates to water control systems.

The invention provides a water control system for a storage tank, the system comprising an inlet valve assembly for connection to a water supply, in use, and means for controlling the inlet valve assembly, wherein the inlet valve assembly is motor driven and is operable to control the flow of water into the tank, in use, and wherein the system is arranged to receive feedback from operation of the motor drive.

By way of example, various embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is a schematic illustration of a water control system according to the invention,

Figure 2 is an exploded view showing the components of a motorised inlet valve assembly for the system of Figure 1, and

Figures 3a and 3b show the valve assembly of Figure 2 in its open and closed positions.

Traditionally, inlet valve assemblies in water supply systems have taken the form of a float-operated valve. These are mechanical devices in which the buoyancy of a float is used to open or close the valve. The devices operate automatically in dependence upon the water level, in the manner of a ballcock in a cistern. Maintenance of valve assemblies of this nature is often difficult due to their relative inaccessibility and can be neglected. In the present invention, it is proposed to replace the traditional float operation of the inlet valve assembly with a motorised operation.

A water control system using such a motorised valve actuation device for this purpose is seen in Figure 1. The system is seen in use on a tank 10 for storing water, which may typically be for a commercial or apartment building. The tank 10 will typically be situated on the roof of the building. Water is supplied to the tank 10, e.g. from a mains water supply 11, via an inlet valve assembly 12. A sensor assembly 13 is located in the tank 10 to monitor the depth of the water. The sensor assembly 13 can also be designed to monitor other parameters, such as water temperature.

The sensor assembly 13 communicates with a control unit 14, via a vent box 15 located on a lid 16 of the tank 10. The control unit 14 is linked to the valve assembly 12 and governs its operation in response to signals from the sensor assembly 13. A conventional manually operated isolation valve 17 may be provided between the valve assembly 12 and the mains water supply 11, to allow the water supply to be cut-off.

The control unit 14 can conveniently be sited remotely from the tank 10 for ease of use, eg by maintenance engineers.

Figure 2 shows the inlet valve assembly 12 in more detail. The assembly 12 comprises an electric servo motor 20 which is coupled via a gear train 21 to a disc valve mechanism 22. The mechanism 22 comprises a pair of interengageable ceramic discs 23, 24. The discs 23, 24 have respective apertures 25, 26 and are rotatable with respect to each other between respective end positions where the apertures are in line (Figure 3a), allowing flow through the valve, or occluded (Figure 3b), preventing flow. The discs are therefore able to control the flow of water into the tank 10.

The motor 20 drives the disc valve mechanism 22 to its open and closed positions via the gear train 21. The motor 20 can automatically selfcalibrate the closed position by driving the mechanism 22 to its physical endstop, and can set the open position as a fixed angle from the closed position. Alternatively, the open and closed positions can be manually set, or determined by any other suitable means (e.g. by micro-switches at the two extremes).

Operation of the motor 20 is electronically controlled by a printed circuit board (PCB) 27. The PCB 27 is connected to the control unit 14 via the vent box 15. An advantage of using this kind of motor is that it provides feedback to the PCB 27. The feedback will be in the form of a current profile and this can be used to determine the position and movement of the motor 20 and hence, via the gear train 21, of the disc valve mechanism 22 itself.

The feedback current profile is a measure of the current drawn by the motor 20 through its operating cycle, e.g. a sweep of the gear train. This feedback can be used to compare the actual performance of the motor 20 with a normal or expected current profile. This will then give an indication of the extent of any deviation from the norm. Thus, if for any reason it takes longer than usual to fully open the disc valve mechanism 22 or perhaps more torque than usual to fully close it, this will be detectable in the feedback as an increase in the current profile at a particular point in the cycle. The control unit 14 can be set to trigger various signals in response to this feedback, e.g. to warn of a disc valve mechanism 22 that is not fully closed or that it is slightly sticky (e.g. stiff) in operation. This allows the possibility of a detailed monitoring of the mechanism 22 performance and operation to take place on a continuous basis, and remotely.

A change in current profile with respect to the normal/expected current profile can be used to detect the nature of a fault in the inlet valve 12 assembly. The change in current profile can indicate a stuck or stiff disc valve mechanism 22, failure in the gear train 21, and/or failure of the motor 20. For example, if the measured current profile is too low, this may indicate a problem with the servo motor or non-engagement of the gear train. If any fault is detected, the control unit 14 may give an indication/warning. Such an indication/warning could be given by LED's, or any other form of display or signal. For serious faults, for example where the disc valve mechanism 22 is stuck in the open position, an audible, as well as a visual, alarm could be given to indicate immediate action is necessary to avoid water overflow from the tank 10.

The control unit 14 can be programmed to take various different actions based on the magnitude of the detected change in the current profile. For example, if the change in the current profile is low to medium, a message or indication could be given to schedule maintenance. If the change in current profile is particularly large, indicating a more serious problem with the disc valve mechanism 22, the control unit 14 could close it to avoid water overflow, and alert the failure of the mechanism by showing a warning light and/or some other form of alarm.

The control unit 14 can also be programmed to initiate remedial action in certain circumstances. For example, if the disc valve mechanism 22 operation is becoming slightly sticky and/or stiff, the feedback would indicate this by an increase in the current profile at a particular point where the stickiness, or stiffness, occurs. Based on this, the control unit 14 could operate the mechanism 22 through several opening and closing cycles in order to free it up and fix the fault. Such sticky/stiff operation can result when the mechanism 22 is used only sporadically.

In some cases, particularly where the disc valve mechanism 22 has a low usage, the control unit 14 could be programmed to perform a periodic operation of the mechanism to ensure that stickiness/stiffness, due to inactivity, does not occur.

The control unit 14, using the sensor assembly 13, can also be programmed to provide a warning indication/alarm if other parameters, such as the temperature of the water, move outside their normal operating range, or when the water level becomes too low.

Although a disc valve mechanism 22 comprising a pair of apertured ceramic discs has been disclosed, and is preferred, any suitable valve mechanism could be used. Furthermore, the sensor assembly 13 has been shown connected to the control unit 14 via vent box 15. In some arrangements, the sensor assembly 13 may be connected directly to the control unit 14.

By providing the inlet valve assembly 12 with motor drive using a servo motor, the arrangement provides the advantage that the operation of the assembly is constantly monitored, and any faults can be immediately indicated. Furthermore, more minor faults can be automatically corrected, and/or routine periodic operation can be performed to reduce potential faults.

It will be appreciated that the arrangement described above is suitable for use in other applications, including for example applications where two tanks (twin tanks) are provided. In that case, an inlet valve assembly may be located in each tank, or a single inlet valve assembly could 5 be used for both tanks.

Claims

1. A water control system for a storage tank, the system comprising an inlet valve assembly for connection to a water supply, in use, and means for controlling the inlet valve assembly, wherein the inlet valve assembly is motor driven and is operable to control the flow of water into the tank, in use, and wherein the system is arranged to receive feedback from operation of the motor drive.

2. A system as claimed in claim 1 and further comprising a sensor assembly for monitoring the depth of the water in the tank, in use, the control means being arranged to control the inlet valve assembly in response to signals from the sensor assembly.

3. A system as claimed in any preceding claim, wherein the inlet valve assembly is driven by an electric motor and the control means is arranged to derive feedback in the form of a current profile from the motor, which is used in the operation of the inlet valve assembly.

4. A system as claimed in claim 3, wherein the control means is arranged to be operable to compare the current profile derived from the feedback with an expected current profile in order to determine the performance of the inlet valve assembly.

5. A system as claimed in claim 4, wherein when the current profile derived from the feedback does not match the expected current profile, the control means is arranged to issue a warning indicating a fault.

6. A system as claimed in claim 5, wherein when the current profile derived from the feedback does not match the expected current profile, the control means is arranged to operate the inlet valve assembly through several opening and closing cycles in order fix a fault.

7. A system as claimed in any preceding claim wherein the control means is operable to periodically operate the inlet valve assembly in order to reduce the possibility of a fault.

8. A system as claimed in any one of claims 2 to 7, wherein the sensor assembly is further operable to measure the temperature of the water in the tank, in use.

9. A system as claimed in any preceding claim wherein the control means comprises a control unit which is operable to determine the position and movement of the inlet valve assembly based on feedback from its motor drive.

10. A system as claimed in any preceding claim wherein the inlet valve assembly comprises a valve mechanism having a pair of interengagable apertured discs.