Controlling chemical dispense operations based on conductivity offset

• US 6,892,143 B2
• Filed: 05/22/2003
• Issued: 05/10/2005
• Est. Priority Date: 05/22/2003
• Status: Active Grant

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Ecolab, Inc.
• Inventors: May, Robert Eugene, Peterson, Jeff W., Howes, Ronald Bruce Jr.
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): VO, HIEN XUAN
• Application Number:
  US10/444,823
• Publication Number:
  US 20040236522A1
• Time in Patent Office: 719 Days
• Field of Search: 702/31, 702/25, 702/30, 702 22- 23, 700/9, 700/80, 700/239, 700/265, 700/283, 340/853.3, 340/853.2, 340/870.07, 705/1
• US Class Current: 702/31
• CPC Class Codes: A47L 15/0055 Metering or indication of used products, e.g. type or quantity of detergent, rinse aid or salt; for measuring or controlling the product concentration
• CPC Class Codes: A47L 15/0063 using remote monitoring or controlling of the dishwasher operation, e.g. networking systems
• CPC Class Codes: A47L 15/241 the dishes moving in a horizontal plane
• CPC Class Codes: A47L 15/4418 in the form of liquids A47L15/4409, A47L15/4436, A47L15/4445 take precedence
• CPC Class Codes: A47L 15/4436 in the form of a detergent solution made by gradually dissolving a powder detergent cake or a solid detergent block
• CPC Class Codes: A47L 15/46 Devices for the automatic control of the different phases of cleaning ; Controlling devices A47L15/449 takes precedence
• CPC Class Codes: A47L 2401/023 Quantity or concentration of the consumable product
• CPC Class Codes: A47L 2401/30 Variation of electrical, magnetical or optical quantities
• CPC Class Codes: A47L 2501/07 Consumable products, e.g. detergent, rinse aids or salt
• CPC Class Codes: A47L 2501/26 Indication or alarm to the controlling device or to the user
• CPC Class Codes: D06F 2101/12 Washing temperature
• CPC Class Codes: D06F 2101/14 Time settings
• CPC Class Codes: D06F 2105/58 Indications or alarms to the control system or to the user
• CPC Class Codes: D06F 34/22 Condition of the washing liquid, e.g. turbidity
• CPC Class Codes: G01N 27/06 of a liquid involving electrolysis G01N27/26
• CPC Class Codes: G05D 11/138 by sensing the concentration of the mixture, e.g. measuring pH value

Abstract

A system and method is disclosed for controlling chemical dispense operations based on a conductivity offset determined for a chemical solution. The chemical dispense operations are performed by or in conjunction with operation of a utility device, such as a warewashing machine. The chemical solution is formed in a solution tank device by combining water with at least one component chemical product. The conductivity offset, which is the conductivity of the water, is used to normalize the conductivity estimated for the chemical solution relative to the component chemical product in the solution. During various points in time during operation of the utility device, the normalized conductivity is compared to a conductivity setpoint, and if the normalized conductivity falls below the conductivity setpoint, a specified volume of the component chemical product is supplied to the solution tank.

Claims

1. In a computer system, a method for controlling conductivity of a chemical solution situated in a solution storage tank, the chemical solution being formed by combining at least one component chemical product with water in the solution storage tank, the method comprising:

determining a conductivity measurement associated with the water;

after the chemical solution is formed in the solution storage tank, calculating a conductivity measurement for the chemical solution, wherein the conductivity measurement indicates a percent concentration of the component chemical product relative to water in the chemical solution; and

analyzing the conductivity measurement associated with the water, the conductivity measurement of the chemical solution and a conductivity setpoint specified for the chemical solution to determine whether the component chemical product should be supplied to the solution storage tank, wherein the conductivity setpoint indicates a desired percent concentration of the component chemical product relative to water in the chemical solution.

2. A method as defined in claim 1, wherein the act of determining a conductivity measurement associated with the water comprises:

prior to supplying the component chemical product to the solution storage tank, filling the solution storage tank with the water and analyzing one or more samples of the water to generate information related to the conductivity of the water.

3. A method as defined in claim 2, wherein the act of determining a conductivity measurement associated with the water further comprises:

analyzing the information related to the conductivity of the water to render the conductivity measurement associated with the water.

4. A method as defined in claim 3, further comprising:

following the act of determining the conductivity measurement associated with the water, supplying the component chemical product to the solution storage tank to begin formation of the chemical solution therein.

5. A method as defined in claim 4, wherein the act of calculating a conductivity measurement of the chemical solution comprises:

analyzing one or more samples of the chemical solution to generate information related to conductivity of the chemical solution; and

analyzing the information related to the conductivity of the chemical solution to render the conductivity measurement for the chemical solution.

6. A method as defined in claim 1, wherein the analyzing act comprises:

subtracting the conductivity measurement associated with the water from the conductivity measurement of the chemical solution to render an actual conductivity reading for the chemical solution; and

comparing the actual conductivity reading of the chemical solution to the conductivity setpoint.

7. A method as defined in claim 6, further comprising:

if the actual conductivity reading for the chemical solution is less than the conductivity setpoint, requesting that a specified volume of component chemical product be supplied to the solution storage tank.

8. A method as defined in claim 7, wherein the specified volume is defined based on a relative discrepancy between the actual conductivity reading and the conductivity setpoint.

9. A method as defined in claim 7, wherein the specified volume is a predetermined volume that is to be supplied to the solution storage tank each time the actual conductivity reading of the chemical solution is less than the conductivity setpoint.

10. A method as defined in claim 7, further comprising:

if the actual conductivity reading for the chemical solution is greater than the conductivity setpoint, requesting that a specified volume of water be supplied to the solution storage tank.

11. A method as defined in claim 10, wherein the specified volume of water is defined based on a relative discrepancy between the conductivity measurement and the normalized conductivity setpoint.

12. A method as defined in claim 1, wherein the analyzing act comprises:

adding the conductivity measurement associated with the water to the conductivity setpoint to render an normalized conductivity setpoint for the chemical solution; and

comparing the conductivity measurement of the chemical solution to the normalized conductivity setpoint.

13. A method as defined in claim 12, further comprising:

if the conductivity measurement of the chemical solution is less than the normalized conductivity setpoint, requesting that a specified volume of component chemical product be supplied to the solution storage tank.

14. A method as defined in claim 13, wherein the specified volume is defined based on a relative discrepancy between the conductivity measurement and the normalized conductivity setpoint.

15. A method as defined in claim 13, wherein the specified volume is a predetermined volume that is to be supplied to the solution storage tank each time the conductivity measurement of the chemical solution is less than the normalized conductivity setpoint.

16. A method as defined in claim 13, further comprising:

if the conductivity measurement of the chemical solution is greater than the normalized conductivity setpoint, requesting that a specified volume of water be supplied to the solution storage tank.

17. A method as defined in claim 16, wherein the specified volume of water is defined based on a relative discrepancy between the conductivity measurement and the normalized conductivity setpoint.

18. A method as defined in claim 1, wherein the chemical solution in the solution storage tank is used by a warewashing machine for application to articles placed therein during one or more wash processes performed in the warewashing machine.

19. A method as defined in claim 18, wherein the act of determining conductivity measurement associated with the water is performed prior to any of the one or more wash processes being performed in the warewashing machine.

20. A method as defined in claim 19, further comprising:

repeating the calculating and analyzing acts during each of the one or more wash processes performed in the warewashing machine.

21. A method as defined in claim 20, further comprising:

requesting supply of the component chemical product to the solution storage tank if the sum of the conductivity measurement associated with the water and the conductivity setpoint is greater than the conductivity measurement of the chemical solution.

22. A method as defined in claim 21, wherein the requesting act is repeated for each of the one or more wash processes performed in the warewashing machine.

23. A method as defined in claim 20, further comprising:

requesting supply of the component chemical product to the solution storage tank if the conductivity setpoint is greater than a relative difference between the conductivity measurement associated with the water and the conductivity measurement of the chemical solution.

24. A method as defined in claim 23, wherein the requesting act is repeated for each of the one or more wash processes performed in the warewashing machine.

25. A method as defined in claim 1, further comprising:

transmitting at least one of the conductivity measurement for the chemical solution and the conductivity measurement associated with the water to a remote computer over a network connection.

26. A method as defined in claim 1, further comprising:

transmitting results rendered by the analyzing act to a remote computer over a network connection.

27. A system for controlling conductivity of a chemical solution situated in a solution storage tank, the chemical solution being formed by combining at least one component chemical product with water in the solution storage tank, the system comprising:

a sensor sensing first information related to inherent conductivity of the water and second information related to conductivity of the chemical solution, wherein the conductivity of the chemical solution indicates percent concentration of the component chemical product relative to water in the chemical solution; and

a controller communicatively coupled to the sensor for receiving the first and second information and analyzing the first information to render a conductivity reading for the water and the second information to render a conductivity reading for the chemical solution, wherein the controller analyzes the conductivity reading for the water, the conductivity reading for the chemical solution and a conductivity setpoint specified for the chemical solution to determine whether the component chemical product should be supplied to the solution storage tank, wherein the conductivity setpoint indicates a desired percent concentration of the component chemical product relative to water in the chemical solution.

28. A system as defined in claim 27, wherein the sensor comprises an inductive probe.

29. A system as defined in claim 27, wherein the sensor comprises a conductive cell.

30. A system as defined in claim 27, wherein the controller comprises a solid state, non-volatile memory device.

31. A system as defined in claim 27, wherein the chemical solution in the solution storage tank is used by a utility device to perform a task comprising one or more wash processes, wherein the chemical solution is applied to one or more objects during the one or more wash processes.

32. A system as defined in claim 31, wherein the sensor senses the first information and the controller analyzes the first information to render the conductivity reading for the water prior to any of the one or more wash processes being performed.

33. A system as defined in claim 32, wherein the sensor senses the second information, the controller analyzes the second information to render the conductivity reading for the chemical solution, and the controller analyzes the conductivity reading for the water, the conductivity reading for the chemical solution and the conductivity setpoint specified for the chemical solution to determine whether the component chemical product should be supplied to the solution storage tank during each of the one or more wash processes.

34. A system as defined in claim 33, wherein the utility device is a warewashing machine that applies the chemical solution to articles placed therein during the one or more wash processes.

35. A system as defined in claim 27, wherein the controller determines that the component chemical product should be supplied to the solution storage tank if the conductivity setpoint is greater than a relative difference between the conductivity reading for the water and the conductivity reading for the chemical solution.

36. A system as defined in claim 27, wherein the controller determines that the component chemical product should be supplied to the solution storage tank if the sum of the conductivity reading for the water and the conductivity setpoint is greater than the conductivity reading for the chemical solution.

37. A system as defined in claim 27, wherein the controller is connected by a network interface to a communication network, wherein data generated from analyses performed by the controller is transmitted by the network interface to a server computer over the communication network.

38. A system as defined in claim 27, wherein the controller is connected by a network interface to a communication network, wherein the first information and the second information are transmitted by the network interface to a server computer over the communication network.

39. A computer program storage device accessible to a computing system and encoding a computer program for executing a computer process for controlling conductivity of a chemical solution situated in a solution storage tank, the chemical solution being formed by combining at least one component chemical product with water in the solution storage tank, the computer process comprising acts of:

determining a conductivity measurement associated with the water;

after the chemical solution is formed in the solution storage tank, calculating a conductivity measurement for the chemical solution, wherein the conductivity measurement indicates a percent concentration of the component chemical product relative to water in the chemical solution; and

analyzing the conductivity measurement associated with the water, the conductivity measurement of the chemical solution and a conductivity setpoint specified for the chemical solution to determine whether the component chemical product should be supplied to the solution storage tank, wherein the conductivity setpoint indicates a desired percent concentration of the component chemical product relative to water in the chemical solution.

40. A computer program storage device as defined in claim 39, wherein the act of determining a conductivity measurement associated with the water comprises:

prior to supplying the component chemical product to the solution storage tank, filling the solution storage tank with the water and analyzing one or more samples of the water to generate information related to the conductivity of the water.

41. A computer program storage device as defined in claim 40, wherein the act of determining a conductivity measurement associated with the water further comprises:

analyzing the information related to the conductivity of the water to render the conductivity measurement associated with the water.

42. A computer program storage device as defined in claim 41, the computer process further comprising:

following the act of determining the conductivity measurement associated with the water, supplying the component chemical product to the solution storage tank to begin formation of the chemical solution therein.

43. A computer program storage device as defined in claim 42, wherein the act of calculating a conductivity measurement of the chemical solution comprises:

analyzing one or more samples of the chemical solution to generate information related to conductivity of the chemical solution; and

analyzing the information related to the conductivity of the chemical solution to render the conductivity measurement for the chemical solution.

44. A computer program storage device as defined in claim 39, wherein the analyzing act comprises:

subtracting the conductivity measurement associated with the water from the conductivity measurement of the chemical solution to render an actual conductivity reading for the chemical solution; and

comparing the actual conductivity reading of the chemical solution to the conductivity setpoint.

45. A computer program storage device as defined in claim 44, the computer process comprising:

if the actual conductivity reading for the chemical solution is less than the conductivity setpoint, requesting that a specified volume of component chemical product be supplied to the solution storage tank.

46. A computer program storage device as defined in claim 45, wherein the specified volume is defined based on a relative discrepancy between the actual conductivity reading and the conductivity setpoint.

47. A computer program storage device as defined in claim 45, wherein the specified volume is a predetermined volume that is to be supplied to the solution storage tank each time the actual conductivity reading of the chemical solution is less than the conductivity setpoint.

48. A computer program storage device as defined in claim 39, wherein the analyzing act comprises:

adding the conductivity measurement associated with the water to the conductivity setpoint to render an normalized conductivity setpoint for the chemical solution; and

comparing the conductivity measurement of the chemical solution to the normalized conductivity setpoint.

49. A computer program storage device as defined in claim 48, the computer process further comprising:

if the conductivity measurement of the chemical solution is less than the normalized conductivity setpoint, requesting that a specified volume of component chemical product be supplied to the solution storage tank.

50. A computer program storage device as defined in claim 49, wherein the specified volume is defined based on a relative discrepancy between the conductivity measurement and the normalized conductivity setpoint.

51. A computer program storage device as defined in claim 49, wherein the specified volume is a predetermined volume that is to be supplied to the solution storage tank each time the conductivity measurement of the chemical solution is less than the normalized conductivity setpoint.

52. A computer program storage device as defined in claim 39, wherein the chemical solution in the solution storage tank is used by a utility device to perform a task comprising one or more wash processes, wherein the chemical solution is applied to one or more objects during the one or more wash processes.

53. A computer program storage device as defined in claim 52, wherein the act of determining conductivity measurement associated with the water is performed prior to any of the one or more wash processes being performed.

54. A computer program storage device as defined in claim 53, the computer process further comprising:

repeating the calculating and analyzing acts during each of the one or more wash processes.

55. A computer program storage device as defined in claim 54, the computer process further comprising:

requesting supply of the component chemical product to the solution storage tank if the sum of the conductivity measurement associated with the water and the conductivity setpoint is greater than the conductivity measurement of the chemical solution.

56. A computer program storage device as defined in claim 55, wherein the requesting act is repeated for each of the one or more wash processes.

57. A computer program storage device as defined in claim 54, the computer process further comprising:

requesting supply of the component chemical product to the solution storage tank if the conductivity setpoint is greater than a relative difference between the conductivity measurement associated with the water and the conductivity measurement of the chemical solution.

58. A computer program storage device as defined in claim 57, wherein the requesting act is repeated for each of the one or more wash processes.

59. A computer program storage device as defined in claim 39, the computer process further comprising:

transmitting at least one of the conductivity measurement for the chemical solution and the conductivity measurement associated with the water to a remote computer over a network connection.

60. A computer program storage device as defined in claim 39, the computer process further comprising:

transmitting results rendered by the analyzing act to a remote computer over a network connection.