WATER TREATMENT CONTROL SYSTEMS AND METHODS OF USE

• US 20080237148A1
• Filed: 03/28/2008
• Published: 10/02/2008
• Est. Priority Date: 12/21/2004
• Status: Active Grant

• Current Assignee: Evoqua Water Technologies LLC
• Original Assignee: Siemens Industry Incorporated (Siemens AG)
• Inventors: Marcukaitis, James, Thomas, Edward, Dennis, Richard, Rhodes, Jeffery
• Granted Patent: US 7,867,401 B2
• Time in Patent Office: Days
• US Class Current: 210/759
• CPC Class Codes: C02F 1/008 Control or steering systems not provided for elsewhere in subclass C02F
• CPC Class Codes: C02F 2209/006 comprising a software program or a logic diagram
• CPC Class Codes: C02F 2209/04 Oxidation reduction potential [ORP]
• CPC Class Codes: C02F 2209/29 Chlorine compounds
• CPC Class Codes: C02F 2209/40 Liquid flow rate
• CPC Class Codes: C02F 2303/185 The treatment agent being halogen or a halogenated compound

Abstract

The control systems and technique can regulate or control operations of a water treatment system in a primary control mode and, when appropriate, in a secondary or an alternate control mode. The primary control can represent a normal control mode during which the water treatment system is intended to operate. The alternate control mode can represent a second control or mode of operation. The systems can be operated to control or facilitate regulation, monitoring, and performance of one or more operating parameters of one or more water systems between, or to and from, a first mode, a second or alternate mode, and, in some cases, a third or even a fourth control mode. The change in control mode can be triggered by identifying one or more predetermined, pre-selected, and/or programmed conditions.

Claims

1. A method of controlling addition of an oxidizing compound to a water treatment system comprising:

measuring a value of a process parameter of the water treatment system;

generating a first control signal in a first control mode when the value of the process parameter is within a first range; and

generating a second control signal in a second control mode when the value of the process parameter is within a second range.

2. The method of claim 1, wherein the process parameter corresponds to an oxidation reduction potential of water in the water treatment system.

3. The method of claim 1, wherein the first control signal is based on a difference between the value of the process parameter and a set point.

4. The method of claim 3, wherein the first control signal is further based on a rate of change of the value of the process parameter.

5. The method of claim 1, wherein the second control signal is based on a difference between the value of the process parameter and an alarm limit.

6. The method of claim 5, wherein the second control signal is further based on a rate of change of the value of the process parameter.

7. The method of claim 1, further comprising measuring a second process parameter of the water treatment system.

8. The method of claim 7, further comprising generating a third control signal when a magnitude of a difference of a value of the second process parameter and a second set point is less than a tolerance.

9. The method of claim 8, further comprising generating a fourth control signal in a fourth control mode when the magnitude of the difference of the value of the second process parameter and the second set point is greater than the tolerance.

10. The method of claim 2, further comprising actuating a valve to regulate the addition of the oxidizing compound based on at least one of the first and second control signals.

11. A method of controlling addition of an oxidizing compound to a water treatment system comprising:

specifying a first set point representing a first desired operating condition of the water treatment system;

specifying a second set point and a tolerance representing a second desired operating condition of the water treatment system;

generating a first input signal corresponding to a first operating parameter of the water treatment system;

generating a second input signal corresponding to a second operating parameter of the water treatment system;

generating a first output signal based on a difference between the first input signal and the first set point when a difference between the second input signal and the second set point is less than the tolerance; and

generating a second output signal based on the first input signal and a second set point when the difference between the second input signal and the second set point is greater than the tolerance.

12. The method of claim 11, wherein the first operating parameter is an oxidation reduction potential.

13. The method of claim 12, wherein the second operating parameter is a concentration of the oxidizing compound in the water treatment system.

14. The method of claim 13, wherein generating the first output signal is based on a lag time of water flowing in the water treatment system.

15. The method of claim 14, wherein generating the first output signal is further based on a rate of change of the first input signal.

16. The method of claim 14, wherein generating at least one of the first and second output signals utilizes at least one of adaptive, proportional, proportional-integral, proportional-derivative, and proportional-integral-derivative control algorithms.

17. A method of controlling addition of a compound to a water treatment system comprising:

specifying a primary set point representing an operating condition of the water treatment system;

measuring a primary operating parameter and a secondary operating parameter of the water treatment system;

generating a first output signal based on the primary operating parameter and the primary set point;

identifying an alternate control mode when at least one condition selected from the group consisting of a low first operating parameter, a high first operating parameter, a low second operating parameter, and a high second operating parameter is present; and

generating an alternate output signal based on at least one of the primary operating parameter and the secondary operating parameter when the alternate control mode is identified.

18. The method of claim 17, wherein the first operating parameter corresponds to an oxidation reduction potential of water in the water treatment system and the second operating parameter corresponds to a concentration of an oxidizing species in the water treatment system.

19. The method of claim 18, wherein the alternate output signal is based on the primary operating parameter and an alternate set point.

20. The method of claim 18, wherein the alternate output signal is based on the secondary operating parameter and an alternate set point.

21. The method of claim 17, wherein the first operating parameter corresponds to a concentration of an oxidizing species in the water treatment system and the second operating parameter corresponds to an oxidation reduction potential of water in the water treatment system.

22-27. -27. (canceled)

28. A computer-readable medium having computer-readable signals stored thereon that define instructions that, as a result of being executed by a computer, instruct the computer to perform a method of controlling addition of an oxidizer compound to a water treatment system comprising acts of:

generating a first control signal in a first control mode when a value of a process parameter of the water treatment system is within a first range; and

generating a second control signal in a second control mode when the value of the process parameter is within a second range.

29. The computer-readable medium of claim 28, wherein the act of generating the first control signal is based on a difference between the value of the process parameter and a set point.

30. The computer-readable medium of claim 29, wherein the act of generating the first control signal is further based on a rate of change of the value of the process parameter.

31. The computer-readable medium of claim 28, wherein the process parameter corresponds to an oxidation reduction potential of water in the water treatment system.

32. A computer-readable medium having computer-readable signals stored thereon that define instructions that, as a result of being executed by a computer, instruct the computer to perform a method of controlling addition of an oxidizer compound to a water treatment system comprising acts of:

receiving a first input signal from a first input device disposed to measure a first operating parameter of the water treatment system;

receiving a second input signal from a second input device disposed to measure a second operating parameter of the water treatment system;

generating a first output signal based on the first input signal and a first set point when a difference between the second input signal and the second set point value is less than a tolerance; and

generating a second output signal based on the first input signal and a second set point when the difference between the second input signal and the second set point value is greater than the tolerance.

33. A method of modifying a water treatment system comprising:

installing a controller that generates a first output signal based in a first control mode to regulate a first control parameter, and a second output signal in a second control mode to regulate a second control parameter; and

connecting the controller to a sensing device disposed in the water treatment system to provide a measure of one or more operating parameters of the water treatment system.

34. The method of claim 33, further comprising uploading a computer program to implement a treatment process for the water.

35. The method of claim 33, wherein in the first and second output signals are received by an output device.