Water treatment control system

A water filter system comprising a control system, communication means, piping, actuators, sensors and valves. The control system utilizes a communication bus for controlling and monitoring water flow through the piping via control of the actuators and valves. The communication bus comprises a two-wire network in a loop configuration coupling the various actuators and valves to the control system. The control system includes a display and programmable control logic for monitoring and controlling the actuators and valves. In one embodiment, the communication bus adheres to a Actuator Sensor-Interface (AS-I) standard. The control system is further coupled to other control systems in a water treatment plant and a Supervisory Control and Data Acquisition (SCADA) network.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to water treatment systems, and particularly to a control and communication system for controlling and monitoring components within a water filter system.

2. Description of the Related Art

Surface water such as lake or river water, or subterranean water, is generally treated in a water treatment plant for use as potable or drinkable water. This pre-treated water often contains materials that can cause a bad taste or odor, or is otherwise harmful. For example, the water may contain organic substances from decaying vegetation, or chemicals from various agricultural or industrial applications, such as pesticides and herbicides.

Water treatment plants include a water treatment system consisting of filter beds, pipes, fittings and various actuators, sensors and valves to control the flow of water through the treatment system. Prior art systems include a control system with various discrete control and status lines to various actuators, sensors and valves. Typical prior art water treatment systems may include hundreds of discrete control lines snaking their way in a water treatment plant between the control system and the actuators, sensors and valves. Besides the physical space taken by the discrete control lines, maintainability, testability and reliability of the system may be hampered as a result of the hundreds of lines.

BRIEF SUMMARY OF THE INVENTION

A water treatment system including water filters, a control system, a communications bus, piping, fittings and various devices including actuators (e.g., a vane type actuator, manufactured by K-Tork International, Inc. of Dallas, Tex.), sensors and valves is disclosed. Generally, the flow of water through the system is controlled by various pipes and valves. The valves can be opened and closed either manually (i.e., human intervention) or through an actuator. The control system controls the flow of water through the system by opening and closing the valves via the actuators. A communication bus couples the control system to the various devices of the system.

In one embodiment, the communication bus adheres to the Actuator Sensor-Interface (AS-I) standard. The standard includes a two (2) wire cable configured in a loop configuration. This configuration provides additional reliability to the system should the loop experience a fault somewhere in the line. The cable carries data and power to the various devices.

In one embodiment, the control system comprises a menu driven step-by-step methodology which facilitates the control including regeneration of the filter system by operators with little or no prior training. The control system includes various man-machine and electrical interfaces and programmable logic control for transmitting/receiving control and status data over the communication bus. The man-machine interface allows users to monitor various parameters of the water treatment system through a display and enter commands via a keypad or dedicated computer system. In addition, the control system can control the devices either automatically or through manual human intervention. The control system can be linked to other control systems, including a Supervisory Control and Data Acquisition (SCADA) system or filter panel for the control and monitoring of various devices in a water treatment plant. The link could be based on any communication network standard, but preferably the link is based on Institute of Electrical and Electronic Engineer (IEEE) standard 802.3 (Ethernet).

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows a prior art automated valve system. The system A consists of a control subsystem interface100for a control subsystem (not shown), discrete control lines DL-all and combination valve-actuator-solenoid units102,104,106,108and110. The figure illustrates twenty-five (25) discrete control lines DL-all coupled to the control subsystem interface100. The discrete control lines DL-all are capable of carrying both power and control signals. The discrete control lines DL-all are coupled to the various valve-actuator-solenoid units102,104,106,108and110in bundles of five (5) discrete control lines DL-5. The bundles of five (5) discrete control lines DL-5are wired to a particular interface card in the control subsystem interface100. The control subsystem generally provides a man-machine interface (not shown) for allowing users to manually operate the valves within the system.

For example, the discrete control lines DL-5A are coupled to the interface card100aand the valve-actuator-solenoid102. The interface card100aprovides power and control signals to the valve-actuator-solenoid102. The control signals could include signals to change the states of the valve102, from an open state to a closed state and vice versa.

Power can also be carried over the discrete control lines DL all from the control interface subsystem100to the valves102,104,106,108and110. The power can be used by the valves to energize/de-energize its solenoid for opening and closing the valves and for powering electronics, if any, within the valves.

For instance, a user may desire to close valve102. The user would initiate an action (perhaps the pushing of a button to close a circuit) from the control subsystem to change the state of valve102from open to close. The control subsystem would direct the control subsystem interface to supply the necessary power to the solenoid of the valve102to close said valve.

The above description of the prior art automated valve system demonstrates the shortcomings of discrete control lines system. AlthoughFIG. 1shows five (5) valves and twenty-five (25) discrete control lines, typical applications of such systems can utilize tens of valves and hundreds of discrete control line over distances of hundreds of meters. Maintainability, reliability and testability of the system may be difficult due the number of wires over a particular distance.

FIG. 2illustrates a prior art water treatment system with discrete control lines. The process for treating water includes pre-treated water from a source WATER SOURCE first flowing through an influent valve202prior to entry into a filter bed206. The source WATER SOURCE typically comprises a reservoir, lake, river, or other source of unfiltered water. The filter bed206can include various media to eliminate certain undesirable elements from the pre-treated water. For instance, the filter bed206may utilize a granulated activated carbon bed as an adsorption unit for removing undesirable elements from the pre-treated water. The influent valve202controls the flow of water from the WATER SOURCE to the filter bed206. The level of water in the filter bed206can be ascertained by a level sensor208. The method for ascertaining the water level can be made by various methods known in the art, such as a liquid detector or a sonic sensor.

If the FILTERED water from the filter bed206is determined to be acceptable (method for determining acceptability will be discussed below), a DRAIN valve214, a FILTER TO WASTE valve216and a BACKWASH valve210, a AIRWASH valve212, are all closed to allow the FILTERED water to exit the system via an opened EFFLUENT valve208.

A turbidmeter218is used to determine the turbidity of the FILTERED WATER. Turbidity is one parameter used to determine the quality of water. The quality of potable or drinking water is generally determined by federal, state or community authorities. In addition, a HEAD LOSS device222may provide some indication on whether the filter bed206needs to undergo a backwash process. Consequently, whether the filtered water is acceptable or not is typically ascertained by the turbidity of the FILTERED water and head loss.

Should the turbidity of the filtered water or the pressure differential indicated on the head loss device reach unacceptable levels, more than likely, the filter bed206is no longer capable of removing the undesirable elements from the pre-treated water. Thus, the filter bed206is cleaned by a backwash system including the BACKWASH valve210and a pump220.

During a backwash cycle, the INFLUENT valve202, the EFFLUENT valve208, the AIRWASH valve212, and the FILTER TO WASTE valve216are all closed. First, the water level in the filter bed206is reduced by opening the DRAIN valve214. After the water level is dropped to a certain level (as detected by the level sensor208), the DRAIN valve216is closed and the AIRWASH valve212is opened. The flow of air generated by the blower228initially loosens any undesirable particulate from the media.

The AIRWASH valve212is closed, the BACKWASH valve210is opened and a pump226pumps the FILTERED water back into the filter bed206. The amount of FILTERED water pumped by the pump220may vary in time, so as to create a backwash effect in the filter bed206to remove the undesirable elements from the media. Once the backwash process is completed, the BACKWASH valve210is closed and the FILTER TO WASTE valve216is opened to allow the backwash water to exit the system. The FILTER TO WASTE valve216is then closed and the INFLUENT valve202is opened to allow water from the WATER SOURCE to enter into the filter system.

All of the valves, pumps and sensors (cumulatively, the “devices”) can be controlled or monitored by a control panel200. The devices are coupled to the control panel200via discrete control lines (represented in the figure by dashed lines) in a linear configuration topology. The control panel200can provide the appropriate signal to change the state (open or close) of a valve via the discrete control lines. The control panel200can also typically receive information from a device, such as the level sensor208, the turbidmeter218and various flowmeters220and224. Thus, the operator (not shown) of the control panel200can monitor the turbidity of the FILTERED water or pressure differential from the HEAD LOSS device222and can initiate a backwash process should the turbidity or pressure differential of the FILTERED water reach an unacceptable level.

The number of wires in a discrete control line to a particular device may vary. For example, the discrete control lines from the control panel200to the INFLUENT valve202may require five (5) separate wires, over a distance of one-hundred (100) meters. Therefore, it is possible that the number of wires from the control panel200may exceed a hundred (100) or more wires.

FIG. 3is a block diagram of a water filter system according to the present invention. Each step shown inFIGS. 3-5and described herein below is displayable on the control panel200and controllable by an operator via the control panel. In one embodiment, each step in the control of the water filter is displayed for an operator to initiate manual or automatic control of the filter system. The flow of water through the water filter system is controlled by valves and piping. The process for treating water includes pre-treated water from a source WATER SOURCE first flowing through an influent valve314prior to entry into a filter bed320. The filter bed320can include various media to eliminate certain undesirable elements from the pre-treated water. For instance, the filter bed320may utilize a granulated activated carbon bed media as an adsorption unit for removing undesirable elements from the pre-treated water.

The influent valve314controls the flow of water from the WATER SOURCE to the filter bed320. It is noted that the valves described herein may include an actuator for opening or closing the valve. The actuator may be a vane-type actuator, such as one manufactured by K-Tork International, Inc. of Dallas, Tex. and disclosed in U.S. Pat. No. 6,289,787, said patent incorporated by reference in its entirety. The level of water in the filter bed320can be ascertained by a level sensor322. The sensor322may utilize various known methods for ascertaining the water level, such as a liquid detector or a sonic sensor.

If the FILTERED water from the filter bed320is determined to be acceptable, a DRAIN valve316, a FILTER TO WASTE valve330, an AIRWASH valve328and a BACKWASH valve324are all closed to allow the FILTERED water to exit the system via an opened EFFLUENT valve336.

Various sensors can ascertain various operating parameters of the water treatment system. For example, the state of a valve may be ascertained by a sensor monitoring an actuator coupled to a valve. In addition,FIG. 3illustrates a turbidmeter332used to determine the turbidity of the FILTERED WATER and a HEAD LOSS device360used to measure a pressure differential in the FILTERED water. Thus whether the filtered water is deemed acceptable or not is typically ascertained by the turbidity and pressure differential of the FILTERED water.

Should the turbidity or pressure differential of the filtered water reach unacceptable levels, more than likely, the filter bed320is no longer capable of removing the undesirable elements from the pre-treated water. Thus, the filter bed320is cleaned by a backwash system including the AIRWASH valve328, a AIRWASH blower362, the BACKWASH valve324and a BACKWASH pump364.

During an initial backwash cycle, the level of the water is lowed by closing the INFLUENT valve314, the EFFLUENT valve336, the BACKWASH valve324, the AIRWASH valve328and the FILTER TO WASTE valve330and opening the DRAIN valve316. The level drop can be detected by the level sensor322. Once the level of water in the filter bed320reaches an acceptable level, the INFLUENT valve314, the EFFLUENT valve336, the DRAIN valve316, the BACKWASH valve324and the FILTER TO WASTE valve330remain closed. The AIRWASH valve328is opened and the blower362is turned on. The blower362generates a flow to loosen particulates from the media of the filter bed320.

Next, the AIRWASH valve328is closed, the BACKWASH valve324is opened and the pump364pumps the FILTERED water back into the filter bed320. The amount of FILTERED water pumped by the pump326may vary in time, so as to create a backwash effect in the filter bed320to remove the undesirable elements from the media. Once the backwash process is completed, the FILTER TO WASTE valve330is opened to allow the backwash water to exit the system. The FILTER TO WASTE valve330is then closed and the INFLUENT valve314is opened to allow water from the WATER SOURCE to enter into the filter system and the EFFLUENT valve336is opened to allow the filtered water to exit from the filter system.

All of the valves, pumps and sensors (cumulatively, the “devices”) can be controlled or monitored by a control subsystem300. The devices are generally coupled to the control panel300via a bus312.

In one embodiment, communication and control of the control subsystem300and the devices adhere to the Actuator Sensor-Interface (AS-I) standard. The specification of the AS-I standard is described in Werner R. Kriesel & Otto W. Madelung, AS-I Interface The Actuator-Sensor-Interface for Automation (2nd ed. 1999) and discussed in the following patents (all said patents are incorporated by reference in their entirety): U.S. Pat. No. 6,294,889 for a Process and a Control Device for a Motor Output Suitable for being Controlled through a Communication Bus, U.S. Pat. No. 6,378,574 for a Rotary Type Continuous Filling Apparatus, U.S. Pat. No. 6,332,327 for a Distributed Intelligence Control for Commercial Refrigeration, U.S. Pat. No. 6,127,748 for an Installation for Making Electrical Connection Between an Equipment Assembly and a Command and Control System, U.S. Pat. No. 6,173,731 for an Electrofluidic Modular System, U.S. Pat. No. 6,222,441 for a Process and Circuit for Connecting an Actuator to a Line, U.S. Pat. No. 5,978,193 for a Switchgear Unit Capable of Communication and U.S. Pat. No. 5,955,859 for an Interface Module Between a Field Bus and Electrical Equipment Controlling and Protecting an Electric Motor.

The AS-I bus312is comprised of two (2) wires, preferably fourteen (14) gauge wires, capable of carrying digital data and power to the various devices. The power to the bus312is provided by the control subsystems' power supplies PS1and PS2(such power supplies may include StoneL Corporation, Fergus Falls, Minn., Model No. 459002-FM102). The AS-I standard specifies that the power supply generally provide a low voltage twenty-four (24) volts over the bus312.

The control logic of the control subsystem300is a programmable logic controller (PLC)306. The controller306provides the necessary processors to transmit and receive data over the bus312.

Should the PLC be non-AS-I compliant a gateway304provides the necessary interface for the control subsystem300to transmit and receive digital data and power over the bus312. A display302generally provides status information of the water treatment system. In addition, a man machine interface370provides the necessary interface for a user to initiate various control and monitoring functions of the devices, such as initiating a backwash process. For security, the control subsystem300may include hardware (such as a key lock) or software (password) to prevent unauthorized personnel from using the system.

The AS-I standard generally specifies a master/slave bus configuration. The control subsystem (master) and the devices (slave) are designed to operate on an AS-I bus312. For example, a device may be a valve, such as the INFLUENT valve314. The INFLUENT valve includes a valve, an actuator and an AS-I interface (such interface includes StoneL Corporation of Fergus Falls, Minn., Model No. QZP96C2R-FM105) (the valve combination will be discussed in detail below). The INFLUENT VALVE314is coupled to the AS-I bus312via a switch356. The switch may be a switch such as a StoneL Corporation of Fergus Falls, Minn., Model No. 461002 or Stonel Model No. 461034. The switches generally provide the interface between the bus and the slave devices. In addition, the Model 461034 switch provides a disconnect switch offering a convenient method to remove, replace or repair a slave device while the remainder of the bus devices remain on line.

FIG. 4is a block diagram of a water filter system with a combination interface, actuator and valve assembly, according to the present invention. For example, during normal operations of the water treatment system, an INFLUENT valve400is opened. An actuator402is coupled to the valve400and an AS-I interface404. The AS-I interface404is coupled to an AS-I bus408via a switch406. An exemplary AS-I interface is a StoneL Corporation of Fergus Falls, Minn., Model No. QZP96C2R-FM105. The actuator can be of any type, including a vane-type actuator (such as a K-Tork International, Inc. of Dallas, Tex., vane-type actuator). The state of the valve400can be ascertained by the AS-I interface404. The AS-I interface404may include positioning sensors to ascertain the state (e.g. the position of a disc of a butterfly type valve) of the valve400. In addition, the AS-I interface404includes processing capabilities to communicate digital data and provide power from a bus408.

Referring toFIG. 3, each AS-I Interface includes a processor (not shown) for sending and receiving data from the bus312. The AS-I interfaces are configured in a serial fashion on the bus312and each interface (i.e., each slave) has its own identification number. Furthermore, the AS-I interfaces also provide power from the bus312to energize/de-energize the solenoids of the actuators of the various valves. Consequently, should the filter system operate in the normal mode (i.e., pre-treated water flowing through the filter bed and out of the system), the control subsystem300would provide the necessary power and command to open the INFLUENT valve314and the EFFLUENT valve336, while closing the DRAIN VALVE316, the BACKWASH valve324, the AIRWASH valve328and the FILTER TO WASTE valve330. In addition, should it be necessary to enter a backwash process, the control subsystem300would provide the necessary power and command to the appropriate valves to perform such process (as previously described). Furthermore, the various sensors322,332and360are also coupled to the AS-I bus312via AS-I interfaces358,346and350, respectively. Thus, operating parameters of the water treatment system may be monitored by the control subsystem300via the AS-I bus312.

Although the topology of the various AS-I interfaces and devices can be in a number of configurations, such as a linear configuration or a tree configuration, the preferred topology is a loop configuration (as shown inFIG. 3). The loop configuration provides for better fault tolerance. For example, should the bus312experience a break360, power and data and still be carried over the bus312in either directions A or B, away from the break.

Furthermore, a test sequence may be initiated by the control subsystem300to test the various devices. Upon receipt of a test command, the processor within the AS-I interfaces performs a self-test to determine the status of the device. The results of the self-test are transmitted to the control subsystem300via the bus312.

Next, the control subsystem300is capable of interfacing to a Supervisory Control and Data Acquisition (SCADA) system or other control subsystems via a communication link363. In one embodiment, the communication link363is an Institute of Electrical and Electronic Engineer (IEEE) standard 802.3 bus (ETHERNET). Typically, a water treatment plant includes a number of water filter systems. Therefore, from a single location, the SCADA system can monitor and control the various water filter systems from one location via the communication link363. One skilled in the art could recognize that the various commands from the control subsystem may be manually initiated by a user or be automatically initiated by a software routine.

In a manual mode, a user may initiate a backwash process, e.g., after observing the head loss from the sensor360. The user may initiate the backwash process by pressing appropriate controls in the man machine interface370of the control subsystem300. Thus, the user may view various operating parameters of the water filter system and then take appropriate actions to successfully perform the backwash process based on system prompts received from the control subsystem300.

Also, status from the various devices may be monitored by a user or a software routine for further action. For example, the water treatment system may be damaged should one of the valves in the system malfunction. For instance, should valve400not close upon a command to close, the valve's AS-I interface404could sense the malfunction and trigger an alarm. Since each AS-I device has its own identification device number, the AS-I interface404would transmit the alarm status to the control subsystem410via the bus408, whereby the control subsystem410would identify the malfunctioned valve.

In addition, the devices and control subsystem of the present invention may be pre-packaged in a kit form. The devices and control subsystem may be pre-tested for installation. Consequently, the kit can be used to retrofit existing and new water treatment systems.

FIG. 5is a flow chart of an exemplary method of processing water in a water treatment system, according to the present invention. The method starts at step500. The water treatment system is operating in a normal mode at step502. At step504, a control subsystem transmits power and commands to open an influent and an effluent valves, close all other valves and operate an effluent pump. The commands are typically Actuator Sensor-Interface (AS-I) commands. Next, the turbidity of the water is tested at step506. If the turbidity is good, the method proceeds to step502.

At step506, if the turbidity of the water is not good, the method proceeds to step508, wherein the system enters a backwash mode. At step510, the control subsystem transmits power and commands to open a backwash valve, operate a backwash pump and close all other valves. The method ends at step512.

FIG. 6is a flow chart of another exemplary method of processing water in a water treatment system, according to the present invention. The method starts at step600. At step602, the system is in a manual mode. A user determines whether a backwash process is needed by viewing operating parameters of the system at step604. The operating parameters could be turbidity, head loss or water flow characteristics. At step606, the user, after viewing the operating parameters, determines whether a backwash process is needed to clean the system. If a backwash process is not needed, the method ends at step608. If at step606, the user determines that a backwash is needed, the method proceeds to step610. At step610, the user follows prompts on a display in the control subsystem to initiate and control a backwash process via bus commands. The bus commands could be Actuator Sensor-Interface (AS-I) commands. The method then ends at step608.

InFIG. 7, a flow chart of an exemplary method of identifying faulty devices in a water treatment system, according to the present invention, is disclosed. The method starts at step700. A control subsystem monitors the states of devices that are coupled to a bus, at step702. The devices may include electronic interfaces, actuators, valves and sensors coupled to an Actuator Sensor-Interface (AS-I) bus. The states may be whether a valve is in an open state or a closed state or whether the device is faulty. At step704, if a device has malfunctioned or is faulty, the control subsystem identifies the device by sending a test command and receiving a response via the bus. The response includes the device's identification number. The response is displayed on a display of the control subsystem. After viewing the display of the control subsystem, a user may then have test personnel examine the faulty device for repair or replacement. Consequently, the method ends at step706.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the details of the illustrated apparatus and construction and method of operation may be made without departing from the spirit of the invention. For example, the valves of the system may not necessarily be AS-I compliant valves. Nonetheless, the valves may include AS-I compliant actuators/interface for inclusion of the non-compliant valves on an AS-I complaint bus.