GB2622283A

GB2622283A - Self-unblocking valve apparatus

Info

Publication number: GB2622283A
Application number: GB2213314.4A
Authority: GB
Inventors: Mohammed Nabi Magdi; Vaghela Anish
Original assignee: Rhames Ltd
Current assignee: Rhames Ltd
Priority date: 2022-09-12
Filing date: 2022-09-12
Publication date: 2024-03-13
Also published as: GB202213314D0

Abstract

The control system 300 comprises means (302, 304, 306 fig 3) for obtaining a signal detected by a sensor 214, wherein the signal is indicative of whether a valve member 202 of the valve apparatus 200 is away from a closed position to seal an end of a branch (15 fig 1) of the vacuum sewer system (1 fig 1) from a vacuum station (10 fig 1). The valve member is movable between the closed position and an open position, wherein the open position of the valve member is to enable a wastewater-air mix to pass from the end of the branch to the vacuum station. The control system further comprises means for determining whether the valve member is in a blocked state preventing the valve member from reaching the closed position, in dependence on the signal from the sensor. The control system further comprises means for causing initiation of an unblocking attempt, in dependence on the determination being that the valve member is in the blocked state. The unblocking attempt includes controlling an active valve actuator 212 of the valve apparatus to cause movement of the valve member. Later embodiments relate to, a system (1 fig 1), a method (500 fig 5), and a computer program (306 fig 3).

Description

SELF-UNBLOCKING VALVE APPARATUS

FIELD OF THE INVENTION

Embodiments of the present invention relate to a self-unblocking valve apparatus. In particular, they relate to a self-unblocking valve apparatus in a vacuum sewer system.

BACKGROUND TO THE INVENTION

A vacuum sewer system is an alternative type of sewer system to a gravity sewer system. Vacuum sewer systems are beneficial in sites where deep trenching is not practical due to geological constraints, topography constraints, space constraints, or investment constraints.

A vacuum sewer system comprises a central vacuum station, providing an air vacuum for multiple branches extending therefrom, the end of each branch being connected to a respective branch wastewater tank.

The central vacuum station comprises a vacuum pump and a central collection tank. The vacuum pump generates a vacuum in the central collection tank.

Each branch comprises a pipe arrangement leading to a bottom portion of a branch wastewater tank. The branch wastewater tank is at atmospheric pressure and fills with wastewater. Each branch also comprises a valve apparatus, defining a pressure seal between the central vacuum station and the branch wastewater tank to maintain the vacuum and regulate the flow of wastewater to the central vacuum station.

In use, when a certain fill level is reached in the branch wastewater tank, the valve apparatus will open automatically. This enables the central vacuum station to suck a wastewater-air mix from the branch wastewater tank to the central collection tank.

The valve apparatus closes automatically when the fill level drops to a suitable level. Any vacuum loss is minimal, so the vacuum pump of the central vacuum station only needs to consume a small amount of electrical power to keep the vacuum 'topped up'.

The valve apparatus can open and close passively via pneumatic means, without any electrical actuators or any requirement for an electrical power source.

A problem arises when the valve apparatus becomes stuck open as a result of a blockage, and therefore unable to return to its closed position. This will cause a vacuum leak, rendering the system ineffective until the blockage has been cleared. The system may then take an entire day to recharge the vacuum, which consumes a large quantity of electricity and may affect the durability of the vacuum pump.

In case of a blockage, the valve apparatus is provided with a push button to enable a user to actuate the pneumatic actuator manually. The user can press the push button to open the valve in an attempt to dislodge the blockage.

BRIEF DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

According to an aspect of the invention, there is provided a control system to control a valve apparatus of a vacuum sewer system, the control system comprising means for: obtaining a signal detected by a sensor, wherein the signal is indicative 30 of whether a valve member of the valve apparatus is away from a closed position, wherein the closed position is to seal an end of a branch of the vacuum sewer system from a vacuum station of the vacuum sewer system, wherein the valve member is movable between the closed position and an open position, and wherein the open position of the valve member is to enable a wastewater-air mix to pass from the end of the branch to the vacuum station of the vacuum sewer system; determining whether the valve member is in a blocked state preventing the valve member from reaching the closed position, in dependence on the signal from the sensor; and causing initiation of an unblocking attempt, in dependence on the determination being that the valve member is in the blocked state, and wherein the unblocking attempt includes controlling an active valve actuator of the valve apparatus to cause movement of the valve member.

An advantage is a more convenient vacuum sewer system because the valve blockage can be sensed and cleared automatically without user intervention.

This feature may not be possible via a passive valve actuator so an active valve actuator and sensor are included.

In some examples, the control system is configured to output an alert signal to a communication interface in dependence on the unblocking attempt being unsuccessful. In some examples, the control system is configured to output the alert signal in dependence on a number of a plurality of unsuccessful unblocking attempts initiated by the control system.

An advantage is further improved convenience because multiple automatic attempts can be made to clear the blockage before a user is alerted.

In some examples, the means comprises at least one processor, and at least one memory coupled to the processor and having instructions stored therein, the at least one memory and the instructions configured to, with the processor, 30 cause the above steps to be performed According to a further aspect of the invention, there is provided a valve apparatus comprising the control system, the valve member, and the active valve actuator.

According to a further aspect of the invention, there is provided a system comprising the valve apparatus, and a branch wastewater tank, wherein the valve apparatus is provided within or proximally to the branch wastewater tank.

According to a further aspect of the invention, there is provided a method of 10 operating a valve apparatus in a vacuum sewer system, the method comprising: obtaining a signal detected by a sensor, wherein the signal is indicative of whether a valve member of the valve apparatus is away from a closed position, wherein the closed position is to seal an end of a branch of the vacuum sewer system from a vacuum station of the vacuum sewer system, wherein the valve member is movable between the closed position and an open position, and wherein the open position is to enable a wastewater-air mix to pass from the end of the branch to the vacuum station; determining whether the valve member is in a blocked state preventing the valve member from reaching the closed position, in dependence on the signal from the sensor; and causing initiation of an unblocking attempt, in dependence on the determination being that the valve member is in the blocked state, and wherein the unblocking attempt includes controlling an active valve actuator of the valve apparatus to cause movement of the valve member.

According to a further aspect of the invention, there is provided a computer program that, when run on a control system for a valve apparatus in a vacuum sewer system, causes: obtaining a signal detected by a sensor, wherein the signal is indicative 30 of whether a valve member of the valve apparatus is away from a closed position, wherein the closed position is to seal an end of a branch of the vacuum sewer system from a vacuum station of the vacuum sewer system, wherein the valve member is movable between the closed position and an open position, and wherein the open position is to enable a wastewater-air mix to pass from the end of the branch to the vacuum station; determining whether the valve member is in a blocked state preventing 5 the valve member from reaching the closed position, in dependence on the signal from the sensor; and causing initiation of an unblocking attempt, in dependence on the determination being that the valve member is in the blocked state, and wherein the unblocking attempt includes controlling an active valve actuator of the valve 10 apparatus to cause movement of the valve member.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of various examples of embodiments of the present invention reference will now be made by way of example only to the accompanying drawings in which: FIG. 1 illustrates an example of a vacuum sewer system; FIGS. 2A-2C illustrate examples of a valve apparatus; FIG. 3 illustrates an example of electrical components of a valve apparatus; FIG. 4 illustrates an example of a non-transitory computer-readable storage medium; and FIG. 5 illustrates an example of a method.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE 25 INVENTION FIG. 1 illustrates a vacuum sewer system 1 ('system'). The vacuum sewer system 1 comprises a vacuum station 10, a branch 15, and a branch wastewater tank 22 at an end 20 of the branch 15. In other examples, more branches 15 may be connected to the same vacuum station 10, such that the vacuum station 10 is a central vacuum station.

The branch 15 comprises a pipe arrangement 16 of one or more wastewater pipes extending from the central vacuum station 10 for metres, tens of metres, or more, to the branch waste water tank 22.

The central vacuum station 10 comprises a central collection tank 12, and a vacuum pump 14 for maintaining a vacuum in the central collection tank 12 and each branch 15. Once wastewater has arrived at the central collection tank 12, it can be pumped to a discharge point such as a gravity sewer, treatment station, or a tanker.

The branch 15 comprises a valve apparatus 200. The valve apparatus 200 is provided within or proximally to the branch wastewater tank 22. The term 'proximally' means it is closer to the branch wastewater tank 22 than to the central vacuum station 10. The term 'within' means that the valve apparatus 200 is within a volume of the branch wastewater tank 22, above a maximum fill level of the branch wastewater tank 22. Each valve apparatus 200 is associated with one branch 15 or a subset of one or more branches 15.

In FIG. 1, the pipe arrangement 16 comprises a sewage pipe section 18 extending from one side of the valve apparatus 200 towards the central vacuum station 10, and further comprises a suction pipe section 24 extending from the valve apparatus 200 towards a bottom of the branch wastewater tank 22 to provide a pickup for wastewater in the branch wastewater tank 22.

An example of the valve apparatus 200 is illustrated schematically in FIG. 2A.

The valve apparatus 200 comprises a housing 210 containing a valve member 202.

The valve apparatus 200 of FIG. 2A also comprises a valve pipe section 216.

The valve pipe section 216 has a fluid inlet 218 fluidly connected to the suction pipe section 24, a fluid outlet 220 fluidly connected to the sewage pipe section 18, and a valve seat 222 therebetween.

The valve pipe section 216, the suction pipe section 24, and the sewage pipe section 18, may be integral or separate parts of the pipe arrangement 16.

The illustrated valve member 202 comprises a valve head 204 and a valve stem 206. The illustrated valve member 202 is movable linearly. The illustrated valve member 202 is movable at an oblique angle relative to an axis of the valve pipe section 216. In a closed position (fully closed) of the valve member 202, the valve head 204 is seated against the valve seat 222. The oblique angle enables a seal to be formed.

The valve head 204 and the valve seat 222 are configured to provide an airtight seal in the closed position, to prevent vacuum leakage. In an example, the valve head 204 comprises a material with the hardness of rubber, such as rubber.

When closing the valve apparatus 200, the valve head 204 moves away from the housing 210 and towards the valve seat 222. When opening the valve apparatus 200, the valve head 204 retracts from the valve seat 222 towards the housing 210.

The illustrated valve head 204 is in the form of a conical plunger. This helps to prevent solids in the waste water from getting caught around the valve head 204.

The valve apparatus 200 of FIG. 2A is further provided with a sensor 214, an active valve actuator 212, and a control system 300 to control the active valve actuator 212 in dependence on a signal detected by the sensor 214.

The active valve actuator 212 illustrated in FIG. 2A is an electromechanical valve actuator 212A in the form of a solenoid, to directly control the movement of the valve member 202.

In another example illustrated in FIG. 2C, the valve apparatus 200 is provided with both a passive valve actuator 228 operable without electrical power, and an active valve actuator 212.

In some examples, the active valve actuator 212 may be a type of actuator 212B that is operable to control the passive valve actuator 228 to actuate the valve member 202. The actuator 212B is operable automatically by the control system 300, without user intervention.

Alternatively, the active valve actuator 212 may be operable to actuate the valve member 202 separately from the passive valve actuator 228, without controlling the passive valve actuator 228.

In an implementation, the passive valve actuator 228 is a pneumatic actuator, comprising a diaphragm separating chambers of different pressures. One side of the diaphragm is pressurized in dependence on a wastewater fill level of the branch wastewater tank 22. The other side is pressurized at the vacuum. When a certain fill level is reached, a resulting deflection of the diaphragm is converted to actuation force to cause the valve member 202 to move to its (fully) open position.

In some examples, the valve actuator 212 is outside the housing 210 of the valve, and is configured to control the passive valve actuator 228 by controlling airflow through a small air hose connected to the valve actuator 212.

A suitable active valve actuator 212B for controlling the pneumatic passive valve actuator 228 is an air pump operated by an electric motor. The active valve actuator 212B is operable to direct a jet of air against the diaphragm to control a position of the diaphragm and therefore a position of the valve member 202.

Therefore, the passive valve actuator 228 can be operated using both active and passive methods.

As shown in FIG. 2C, the valve apparatus 200 may further comprise a manual actuator 230 such as a push button, to enable the user to move the valve member 202. In an example, the manual actuator 230 may act on the passive valve actuator 228 (if provided). The manual actuator 230 enables the user to try manually clearing the blockage before they try dismantling the valve apparatus 200.

Referring to FIGS. 2A-2C, the sensor 214 is configured to detect a signal indicative of whether the valve member 202 is away from its closed position.

The signal may indicate when there is a blockage, causing the valve member 202 to be stuck between its closed position and its open position.

A first example of the sensor 214 is a position sensor in the form of an optical time of flight sensor 214A as shown in FIG. 2A. The optical time of flight sensor 214A can comprise a LIDAR (light detection and ranging) sensor, for example. The optical time of flight sensor 214A is secured to the housing 210 of the valve apparatus 200. The optical time of flight sensor 214A is configured to detect a position of part 208 of the valve member 202, in the form of a distance of the part 208 from the optical time of flight sensor 214A. Therefore, if the valve member 202 is not at its closed position, the signal will indicate this.

In FIG. 2A, the optical time of flight sensor 214A is inside the housing 210 and pointing at the part 208 of the valve member 202. The illustrated part 208 of the 25 valve member 202 is at the end of the valve stem 206. The illustrated part 208 of the valve member 202 has an enlarged area relative to at least the valve stem 206, when viewed from the perspective of the optical time of flight sensor 214A. A sensed surface of the part 208 comprises any suitable optically reflective material for being detected by the optical time of flight sensor 214A. 30 In other implementations, another type of time of flight sensor may be used such as an ultrasonic time of flight sensor. However, an optical time of flight sensor 214A has been found to be more precise, lacks linearity problems and double imaging problems, and is more accurate in humid environments suitable for a vacuum sewer system 1.

A second example of the sensor 214 is shown in FIG. 2B, in which the sensor 214 is a pressure sensor 214B. The pressure sensor 214B is connected to the pipe arrangement 16 along the branch 15, to measure a pressure of the vacuum in the branch 15. The pressure sensor 214B is mounted to the vacuum side of the valve apparatus 200. As shown in FIG. 2B, the pressure sensor 214B may be connected to a pipe wall of the pipe arrangement 16. In order to be near the valve member 202, the mounting location of the pressure sensor 214B may be located no more than one metre or no more than 50 centimetres from the valve member 202, along the pipe arrangement 16.

In a third example (not shown), the sensor 214 is a force sensor (not shown) such as a load cell. The force sensor is configured to detect a compression force of a return spring (also not shown) of the valve apparatus 200. The return spring is any appropriate spring configured to urge the valve member 202 to the closed position.

Any combination of the above-described actuators 212, 228 may be used with any combination of the above-described sensors 214.

FIGS. 2A-2B further illustrate a control system 300 secured to the housing 210.

The control system 300 may be mounted elsewhere if required. The control system 300 is operably connected to the sensor 214 and to the active valve actuator 212. Each valve apparatus 200 may comprise its own control system 300. Alternatively, the control system 300 may be shared by multiple valve apparatuses.

FIG. 3 schematically illustrates the electrical components of the valve apparatus 200.

The electrical components firstly include the control system 300. The control system 300 comprises at least one controller 301. The or each controller 301 comprises at least one processor 302, and at least one memory 304 coupled to the processor 302 and having instructions (for example a computer program 306) stored therein, the at least one memory 304 and the instructions configured to, with the processor 302, cause any one or more of the methods described herein to be performed.

The control system 300 may comprise an onboard controller 301 local to the valve apparatus 200 or to the vacuum sewer system 1. The control system 300 may further comprise an offboard controller 301 remote from the valve apparatus 200 or vacuum sewer system 1. The methods described herein may be performed exclusively by an onboard controller 301, or its functions may be distributed between onboard and offboard controllers 301.

The electrical components further include the sensor 214, the active valve actuator 212, a communication interface 224, and a battery 226. The battery 226 provides an onboard power source for the electrical components, for use cases in which an external electricity source is not available. The battery 226 may be mounted on or in the housing 210 or a separate housing.

The communication interface 224 can comprise a wireless interface so that a user does not need to be present to receive and/or transmit communications 25 with the valve apparatus 200. The communication interface 224 may be mounted on or in the housing 210 or a separate housing.

The communication interface 224 can comprise a radio transceiver, transmitter, or receiver. The communication interface 224 can comprise a real or digital subscriber identity module (SIM) enabling connection to a cellular network. The communication interface 224 can comprise an Internet connection. The communication interface 224 can be configured to transmit and/or receive telemetry. The communication interface 224 can be configured to transmit notifications such as alert signals. Telemetry can include any one or more of: the signal from the sensor 214; information dependent on said signal; battery status; location; blockage count number, etc. FIG. 4 illustrates an example of a non-transitory computer-readable storage medium 400 comprising the instructions 306 for loading into the control system 300, such as an optical storage medium (e.g., compact disc), read only memory (ROM), random access memory (RAM), or the like.

In some implementations, the control system 300 is configurable remotely. The control system 300 is configured to receive over-the-air (OTA) programming such as OTA software updates. In an implementation, the condition defined in block 504 may be updateable via an OTA software update. The OTA programming may be received via the communication interface 224.

FIG. 5 illustrates an example of a computer-implemented method 500, which may be executed by the control system 300.

At block 502, the method 500 comprises obtaining the signal detected by the sensor 214. The control system 300 may obtain the signal. The signal may be measured continuously or intermittently, as required.

At decision block 504, the method 500 comprises determining whether the 25 valve member 202 is in a blocked state preventing the valve member 202 from reaching the closed position, in dependence on the signal from the sensor 214. The 'blocked state' is a condition within the control system 300, to be satisfied.

If the sensor 214 is a position sensor (e.g., 214A), the signal can indicate that the valve member 202 is in a blocked state by indicating the position of the sensed part 208 of the valve member 202. The control system 300 can determine whether the valve member 202 is in a blocked state in dependence on obtaining or calculating the distance of the valve member 202 from the position sensor, based on the signal. Satisfaction of the condition may depend on the distance of the sensed part 208 of the valve member 202 being less than a threshold, or greater than a threshold if the position sensor is mounted at an opposite mounting location than shown in FIG. 2A.

If the sensor 214 is a pressure sensor 214B, the signal indicates the valve member 202 being in a blocked state by measuring the pressure of the vacuum in the pipe arrangement 16 between the valve apparatus 200 and the central vacuum station 10. Satisfaction of the condition may depend on the pressure being different than a setpoint, indicating a potential vacuum leak. By using a pressure sensor with known ambient pressure and the ideal pressure for the tank/ or the pipe connected to the valve, then a setpoint can be used. If the pressure is above or below this setpoint then it is possible to infer that the valve is open or closed. For example, if the ideal pressure is 14.5 pounds per square inch and the sensor reads above or below that, the controller can determine that there is something wrong with the valve (e.g., losing pressure).

If the sensor 214 is a force sensor, the signal indicates that the valve member 202 is in a blocked state by indicating the compression force of the return spring. Satisfaction of the condition may depend on the compression force being greater than a threshold, which implies that the return spring is being compressed more than it should be for the closed position of the valve member 202 To prevent false positives, the control system 300 may be configured to require that the signal needs to indicate the blocked state continuously or intermittently for a set duration of time, such as a predetermined duration of time stored in the control system 300. The value of the set duration may be at least three seconds, or at least five seconds, or at least ten seconds. To prevent excessive vacuum leakage in a 'true positive' situation, the value of the set duration may be less than five minutes, or less than one minute, or less than 30 seconds, or less than 20 seconds. In an implementation, the set duration is approximately 14 seconds If the condition of block 504 is satisfied such that the valve member is 5 determined to be in the blocked state, the method 500 progresses towards attempting to automatically unblock the valve apparatus 200.

This comprises proceeding to block 506 which increments an attempt number rn of the unblocking attempt. Then, decision block 508 determines whether the 10 attempt number n exceeds a maximum number N. If n is not greater than N, the method 500 can proceed to block 510, which comprises causing initiation of an unblocking attempt, attempting to unblock the valve member 202.

The unblocking attempt comprises controlling the active valve actuator 212 to cause movement of the valve member 202. The unblocking attempt can comprise temporarily opening the valve member 202, and then closing the valve member 202. The control system 300 may be configured to cause the active valve actuator 212 to temporarily hold the valve member 202 at its open position for a set duration (e.g., predetermined duration) of no more than 20 seconds or no more than 30 seconds or no more than one minute.

After this unblocking attempt, the method 500 then loops back to block 502 to read (obtain) the signal resulting from measurements by the sensor 214 after the unblocking attempt, to determine whether the unblocking attempt was successful.

Then, decision block 504 is repeated. If block 504 determines that the valve 30 member 202 is now not in a blocked state, then the method 500 can either terminate, or loop back to block 502 to continue monitoring for future blockages.

If block 504 determines that the valve member 202 is in the blocked state, then the unblocking attempt has been unsuccessful. In that case, the method 500 proceeds to block 506 which increments the attempt number 'n', then block 508 which determines whether n>N, and then block 510 which attempts to clear the blockage again.

The control system 300 may be configured to execute repeated unblocking attempts at a constrained frequency. For example, after block 510 the control system 300 may wait for a set time (e.g., predetermined duration in the order of at least 3 seconds or at least 5 seconds) before measuring the signal at block 502 to determine whether the condition is satisfied. This is useful for ensuring that the signal, such as pressure, reaches a steady state after the previous unblocking attempt. To minimize cumulative vacuum leakage, the value of the set time may be no greater than 20 seconds or no greater than 30 seconds or no greater than one minute or no greater than two minutes.

The maximum number of attempts N may have any appropriate value, such as five attempts. Tests identified that the first attempt was most likely to clear the blockage, so N=2 may provide a high degree of certainty that the blockage cannot be cleared automatically and manual intervention is required. If the maximum number is N=5, the degree of certainty would be even higher. It would be desirable for N not to be higher than 6 or 10 or 20, to minimise cumulative vacuum leakage from each failed attempt.

If decision block 508 determines that the attempt number n exceeds the maximum number N, the method 500 may instead progress from block 508 to block 512, instead of to block 510. At block 512, the method 500 comprises outputting an alert signal to the communication interface 224, in dependence on the unblocking attempt being unsuccessful. The alert signal may be in the form of a server notification, an email, a text message, an app notification for a software application, or any other appropriate electronic notification. The alert signal may be addressed to a server or a specific device.

The alert signal may include a unique identifier of the valve apparatus 200, to help a user to identify which valve apparatus is blocked.

The alert signal therefore prompts a user or engineer to visit the valve apparatus to attempt to manually clear it.

The blocks illustrated in FIG. 5 may represent steps in a method 500 and/or sections of code in the computer program 306. The illustration of a particular order to the blocks does not necessarily imply that there is a required or preferred order for the blocks and the order and arrangement of the block may be varied. Furthermore, it may be possible for some steps to be omitted, such as the alert-related steps (blocks 506, 508, 512).

In some implementations, the valve apparatus 200 can be connected to one or more further sensors. The branch wastewater tank 22 may be provided with a fill sensor (not shown) connected to the control system 300, to enable a determination of whether the branch wastewater tank 22 has overfilled. The control system 300 may be configured to output an alert signal similar to that described above, if the control system 300 determines that an overfill condition has been satisfied, based on information from the fill sensor.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed.

Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

I/we claim:

Claims

CLAIMS1. A control system to control a valve apparatus of a vacuum sewer system, the control system comprising means for: obtaining a signal detected by a sensor, wherein the signal is indicative of whether a valve member of the valve apparatus is away from a closed position, wherein the closed position is to seal an end of a branch of the vacuum sewer system from a vacuum station of the vacuum sewer system, wherein the valve member is movable between the closed position and an open position, and wherein the open position of the valve member is to enable a wastewater-air mix to pass from the end of the branch to the vacuum station of the vacuum sewer system; determining whether the valve member is in a blocked state preventing the valve member from reaching the closed position, in dependence on the signal from the sensor; and causing initiation of an unblocking attempt, in dependence on the determination being that the valve member is in the blocked state, and wherein the unblocking attempt includes controlling an active valve actuator of the valve apparatus to cause movement of the valve member.
2. The control system of claim 1, wherein in the unblocking attempt, the control system is configured to control the active valve actuator to cause temporary opening of the valve member.
3. The control system of claim 1 or 2, configured to output an alert signal to a communication interface in dependence on the unblocking attempt being unsuccessful.
4. The control system of claim 3, wherein the communication interface comprises a wireless interface.
5. The control system of claim 3 or 4, wherein the control system is configured to output the alert signal in dependence on a number of a plurality of unsuccessful unblocking attempts initiated by the control system.
6. The control system of any preceding claim, configured to determine whether the unblocking attempt is unsuccessful, wherein determining whether the unblocking attempt is unsuccessful comprises reading the signal after the unblocking attempt, and determining whether the valve member is in the blocked state in dependence on the reading of the signal after the unblocking attempt
7. The control system of any preceding claim, wherein the determination of whether the valve member is in a blocked state is further dependent on for how long the signal from the sensor indicates that the valve member is in the blocked 15 state.
8. The control system of any preceding claim, wherein the control system is configured to receive a condition for determining that the valve member is in the blocked state, via over-the-air programming.
9. The control system of any preceding claim, wherein the active valve actuator includes an electromechanical valve actuator to control the movement of the valve member.
10. The control system of any one of claims 1 to 8, wherein the active valve actuator includes an indirect valve actuator configured to control a passive valve actuator to control the movement of the valve member.
11. The control system of claim 10, wherein the passive valve actuator is actuatable passively in dependence on a fill level of a tank of the vacuum sewer system, and is separately actuatable by operation of the active valve actuator.
12. The control system of any preceding claim, wherein the signal from the sensor indicates pressure, wherein the sensor is a pressure sensor, wherein the pressure sensor is configured to measure the pressure in the branch of the vacuum sewer system, the pressure being dependent on a position of the valve 5 member.
13. The control system of any one of claims 1 to 11, wherein the signal from the sensor indicates a position of part of the valve member, and wherein the sensor is a position sensor.
14. The control system of claim 13, wherein the position sensor comprises an optical time of flight sensor.
15. The control system of any one of claims 1 to 11, wherein the signal from the sensor indicates return spring force associated with a return spring for biasing the valve member towards the closed position, and wherein the sensor is a force sensor.
16. A valve apparatus comprising the control system, the valve member, and the active valve actuator, as defined in any one of the preceding claims.
17. The valve apparatus of claim 16, further comprising the sensor.
18. The valve apparatus of claim 16 or 17, further comprising a manual 25 actuator to enable a user to move the valve member.
19. The valve apparatus of claim 16, 17, or 18, further comprising a battery to power at least the active valve actuator.
20. A system comprising the valve apparatus of any one of claims 16 to 19, and a branch wastewater tank, wherein the valve apparatus is provided within or proximally to the branch wastewater tank.
21. The system of claim 20, further comprising a vacuum station including a vacuum pump for maintaining a vacuum in the branch, wherein the valve member in the closed position provides an airtight seal to prevent vacuum leakage, and wherein the valve member in the open position enables the vacuum to suck the wastewater-air mix from the branch wastewater tank towards the vacuum station.
22. A method of operating a valve apparatus in a vacuum sewer system, the method comprising: obtaining a signal detected by a sensor, wherein the signal is indicative of whether a valve member of the valve apparatus is away from a closed position, wherein the closed position is to seal an end of a branch of the vacuum sewer system from a vacuum station of the vacuum sewer system, wherein the valve member is movable between the closed position and an open position, and wherein the open position is to enable a wastewater-air mix to pass from the end of the branch to the vacuum station; determining whether the valve member is in a blocked state preventing the valve member from reaching the closed position, in dependence on the signal from the sensor; and causing initiation of an unblocking attempt, in dependence on the determination being that the valve member is in the blocked state, and wherein the unblocking attempt includes controlling an active valve actuator of the valve apparatus to cause movement of the valve member.
23. A computer program that, when run on a control system for a valve apparatus in a vacuum sewer system, causes: obtaining a signal detected by a sensor, wherein the signal is indicative of whether a valve member of the valve apparatus is away from a closed position, wherein the closed position is to seal an end of a branch of the vacuum sewer system from a vacuum station of the vacuum sewer system, wherein the valve member is movable between the closed position and an open position, and wherein the open position is to enable a wastewater-air mix to pass from the end of the branch to the vacuum station; determining whether the valve member is in a blocked state preventing the valve member from reaching the closed position, in dependence on the signal from the sensor; and causing initiation of an unblocking attempt, in dependence on the determination being that the valve member is in the blocked state, and wherein the unblocking attempt includes controlling an active valve actuator of the valve apparatus to cause movement of the valve member.