Fluid condition monitoring and controlling system for a metalworking fluid central system

• US 5,224,051 A
• Filed: 05/19/1989
• Issued: 06/29/1993
• Est. Priority Date: 05/19/1989
• Status: Expired due to Fees

• Current Assignee: Milacron Industrial Products Inc. (Milacron Holdings Corp.)
• Original Assignee: Cincinnati Machines Incorporated (Fives SA)
• Inventors: Johnson, Jerry T.
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): GORDON, PAUL P
• Application Number:
  US07/354,485
• Time in Patent Office: 1,502 Days
• Field of Search: 364/474.19, 364/474.06, 364/138, 364/148, 364/183, 364/500, 364/509, 364/510, 364/551.02, 364/474.15, 364/474.16, 364/474.11, 210/706, 210/739, 210/742, 210/743, 210/746, 184/6.0, 184/6.1, 184/6.14, 184/6.24, 184/7.4, 184/108, 29/DIG. 50, 29/DIG. 54, 29/DIG. 63, 252/49.5, 340/825.22, 340/825.23, 340/825.06, 137/1, 137/2, 137/4, 137/5, 137/92, 137/392, 408/56, 409/139, 83/169, 51/356
• US Class Current: 700/169
• CPC Class Codes: B23Q 11/1061 using cutting liquids with specially selected composition or state of aggregation
• CPC Class Codes: G01N 33/2894 for metal working or machining
• CPC Class Codes: G05D 21/02 characterised by the use of electric means

Abstract

A metalworking fluid central system through which aqueous cutting fluid recirculates through a plurality of machine tools is provided with an in-line fluid condition monitor which produces real-time fluid composition data for use in controlling the condition of the fluid. Four sensors simultaneously measure temperature, pH, dissolved oxygen and conductivity at hourly intervals and the data is stored in a computer module linked to the monitor. A plurality of diversely located plants are similarly equipped. A computer at a remotely located central monitoring facility selectively connects to the computer modules at the various plants through modems and a telephone system to collect the data daily. The data is analyzed at the central facility and dimensions are made manually and automatically to add components to the fluid at the respective plants or to take other corrective action. Commands and recommendations are communicated to the computer modules at the respective plants where they are manually and automatically implemented by the operation of valves, pumps or other devices or methods to modify the make-up of the fluid in the central system.

Claims

1. A method of maintaining the condition of an aqueous metalworking fluid at a metal working location having located thereat a plurality of metalworking machines, a central reservoir containing a volume of the aqueous metalworking fluid sufficient to service the plurality of machines, and means connected to the machines and the reservoir for circulating fluid through the machines and the reservoir, the fluid being made up of components that include a lubricant and water and being used under conditions that will support contaminating biological activity within it, the method comprising the steps of:

monitoring, in-line with the fluid circulating means, a plurality of different components of the fluid and producing in real time for each monitored component a measurement signal responsive thereto, including an oxygen measurement signal responsive to the dissolved oxygen content of the fluid and a pH measurement signal responsive to the hydrogen ion content of the fluid;

generating, in response to the oxygen measurement signal and the pH measurement signal, at least one monitoring signal carrying information of the pH and oxygen content of the fluid;

analyzing the pH and oxygen content information carried by the monitoring signal; and

modifying, in real time, the content of a third component of the monitored fluid in response to the analysis to control the biological activity therein.

2. The method of claim 1 wherein:

the monitoring step includes the steps of monitoring the dissolved oxygen and pH for time varying changes in the content thereof in the fluid; and

the analyzing step includes the step of analyzing information derived from the measurement signals for time varying changes in the content of the monitored components in the fluid.

3. The method of claim 1 wherein:

the modifying step includes the step of adding the third component to the fluid different from the monitored dissolved oxygen and pH parameters to control biological activity within the monitored fluid in response to the analysis.

4. The method of claim 1 wherein:

the third component content modifying step includes the addition of a biocidal agent to directly affect biologically active components in the fluid.

5. The method of claim 1 further comprising the steps of:

establishing a communication link between the metal working location and a remote monitoring facility;

transmitting the monitoring signal through the communication link to the remote monitoring facility;

the analyzing step including the step of analyzing at the remote location the information carried by the monitoring signal and deriving therefrom information relating to the biological activity of the fluid; and

comparing the derived information with predetermined criteria and generating in response to a result of the comparison an output signal carrying information relating to the maintenance of the composition of the fluid to control biological activity therein.

6. The method of claim 5 for monitoring aqueous metalworking fluid at plurality of metal working locations for biological activity, the method comprising the steps of:

sensing at each metal working location, in real time and in-line with the circulating fluid, at least two components of the metalworking fluid that have a tendency to vary in response to the biological activity within the fluid;

producing at each metal working location at least one monitoring signal carrying data responsive to the content of the sensed component in the fluid thereat;

selectively establishing the communications link between a selected one of the metal working locations and the central monitoring facility located remote from the metalworking locations;

transmitting data from the selected metalworking location to the central monitoring facility over the communications link; and

communicating to the selected metalworking location, in response to the determination, information relating to the addition of the third component to the fluid at the selected metalworking location to control the biological activity in the fluid; and

the modifying step includes the step of adding a quantity of the third component to the fluid in response to the information communicated from the central monitoring facility.

7. The method of claim 1 further comprising the steps of:

monitoring, in-line with the fluid circulating means, a plurality of different parameters of the fluid and producing in real time for each parameter a measurement signal responsive thereto, including, in addition to the first component and second component measurement signals, a fluid temperature measurement signal responsive to the temperature of the fluid and a conductivity measurement signal responsive to the electrical conductivity of the fluid;

generating, in response to the temperature measurement signal and the conductivity signal, at least one monitoring signal carrying information of the temperature and conductivity of the fluid;

analyzing the temperature and conductivity information carried by the monitoring signal; and

initiating, in real time, action to control the concentration and pH of the fluid in response to the analysis.

8. A method of controlling the biological contamination of an aqueous metalworking fluid at a metal working location having located thereat a plurality of metalworking machines, a central reservoir containing a volume of the aqueous metalworking fluid sufficient to service the plurality of machines, and means connected to the machines and the reservoir for circulating fluid through the machines and the reservoir, the fluid being made up of components that include a lubricant and water and being used under conditions that will support contaminating biological activity within it, the method comprising the steps of:

monitoring the fluid in real time by sensing in-line with the circulating fluid at least two of a plurality of different parameters of the fluid, which have a tendency to vary differently in response to biological activity within the fluid;

producing, in real time, measurement signals responsive to each monitored parameter;

analyzing, in real time, information derived from the measurement signals for time varying changes in the sensed parameters caused by biological activity within the fluid; and

modifying the fluid, in real time, to reduce the biological activity within the fluid in response to the analysis.

9. The method of claim 8 wherein:

the monitored parameters that vary in response to biological activity include pH and dissolved oxygen; and

the fluid modifying step includes the step of adding a biocidal agent to the fluid to directly reduce biological activity in the fluid.

10. The method of claim 8 wherein:

the modifying step includes the step of initiating action to modify a third parameter of the fluid different from the at least two monitored parameters to control biological activity within the monitored fluid in response to the analysis and to thereby prevent further variation in the monitored parameters caused by the biological activity.

11. The method of claim 10 wherein:

the action to modify the third parameter includes the addition of a biocidal agent to directly affect biologically active components in the fluid.

12. The method of claim 8 further comprising the steps of:

establishing a communication link between the metal working location and a remote monitoring facility;

transmitting the monitoring signal through the communication link to the remote monitoring facility;

the analyzing step including the step of analyzing at the remote location the information carried by the monitoring signal and deriving therefrom information relating to the biological activity of the fluid; and

comparing the derived information with predetermined criteria and generating in response to a result of the comparison an output signal carrying information relating maintenance of the composition of the fluid to control biological activity therein.

13. The method of claim 12 for monitoring aqueous metalworking fluid at plurality of metal working locations for biological activity, the method comprising the steps of:

sensing at each metal working location, in real time and in-line with the circulating fluid, at least two parameters of the metalworking fluid that have a tendency to vary in response to the biological activity within the fluid;

producing at each metal working location at least one monitoring signal carrying data responsive to variations in the sensed parameters;

selectively establishing the communications link between a selected one of the metal working locations and the central monitoring facility located remote from the metalworking locations;

transmitting data from the selected metalworking location to the central monitoring facility over the communications link; and

communicating to the selected metalworking location, in response to the determination, information relating to biological activity in the fluid at the selected metalworking location that may require corrective action.

14. The method of claim 8 further comprising the steps of:

monitoring, in-line with the fluid circulating means, a plurality of different parameters of the fluid and producing in real time for each parameter a measurement signal responsive thereto, including, in addition to the first and second measurement signals, an fluid temperature measurement signal responsive to the temperature of the fluid and conductivity signal responsive to the electrical conductivity of the fluid;

generating, in response to the temperature measurement signal and the conductivity signal, at least one monitoring signal carrying information of the temperature and conductivity of the fluid;

analyzing the temperature and conductivity information carried by the monitoring signal; and

initiating, in real time, action to control the concentration and pH of the fluid in response to the analysis.

15. A method of controlling the biological activity in an aqueous metalworking fluid at a metal working location having located thereat a plurality of metalworking machines, a central reservoir containing a volume of the aqueous metalworking fluid sufficient to service the plurality of machines, and means connected to the machines and the reservoir for circulating fluid through the machines and the reservoir, the method comprising the steps of:

sensing, in real time and in-line with the circulating fluid at the metal working location, the amount of oxygen dissolved in the fluid;

producing, in real time, a monitoring signal carrying information responsive to the amount of dissolved oxygen sensed;

establishing a communication link between the metal working location and a remote monitoring facility;

transmitting the monitoring signal through the communication link to the remote monitoring facility;

analyzing at the remote location the information carried by the monitoring signal and deriving therefrom information relating to the biological activity of the fluid;

comparing the derived information with predetermined criteria and generating in response to a result of the comparison an output signal carrying information relating maintenance of the composition of the fluid to control biological activity therein;

transmitting the output signal from the remote facility to the metalworking location; and

modifying the composition of the monitored fluid in response to the output signal to reduce the biological activity therein.

16. The method of claim 15 wherein the transmission step is performed over a telephone communication link between the remote location and the system.

17. The method of claim 15 further comprising the step of initiating the transmission in response to an interrogation signal from the remote facility.

18. The method of claim 15 further comprising the step of initiating the transmission in accordance with a predetermined schedule.

19. The method of claim 15 further comprising the step of initiating from the site of central system the transmission in response to information derived in the monitoring step.

20. The method of claim 15 further comprising the steps of:

storing data derived in the monitoring step and subsequently generating the signal from the stored data representative of the history of the monitored parameter of the fluid.

21. The method of claim 15 wherein the transmission step is initiated at programmed intervals to transmit the plurality of signals for analysis to the remote location, and is initiated at more frequent intervals to test the information for specific characteristics.

22. A method of controlling the biological activity in aqueous metalworking fluids at each of a plurality of different metal working locations, wherein each metal working location has located thereat a plurality of metalworking machines, a central reservoir containing a volume of the aqueous metalworking fluid sufficient to service the plurality of machines at the location, and means connected to the machines and the reservoir for circulating fluid through the machines at the location and the reservoir, the method comprising the steps of:

sensing at each metal working location, in real time and in-line with the circulating fluid, at least two parameters of the metalworking fluid that have a tendency to vary in response to the activity within the fluid at the respective location;

producing at each metal working location a monitoring signal carrying data responsive to variations in the sensed parameter;

selectively establishing a communications link between a selected one of the metal working locations and a central monitoring facility located remote from the metalworking locations, the facility having means thereat for analyzing data received from the locations and for generating output signals containing information for the control of the compositions of metalworking fluids in response to the analyses;

transmitting data from the selected metalworking location to the central monitoring facility over the communications link;

analyzing the transmitted data at the monitoring facility to determine whether corrective action is needed at the selected metalworking location to control biological activity in the fluid thereat, and producing an output signal in response to a determination that corrective action is needed;

communicating from the monitoring facility to the selected metalworking location, in response to the determination, the output signal carrying information relating to corrective action to be taken; and

initiating corrective action to control biological activity in the fluid at the selected metalworking location in response to the output signal communicated from the monitoring facility.

23. The method of claim 22 wherein:

the output signal transmitting and communicating steps include the step of transmitting a control signal from the remote facility to the selected metalworking location in response to the determination and automatically controlling equipment at the metalworking location in response thereto to perform the needed corrective action on the fluid thereat to control the biological activity therein.

24. The method of claim 22 wherein the communicating step further comprises the step of:

communicating to an operator at the fluid site information in response to the signal from the remote location.

25. The method of claim 24 further comprising the step of:

modifying the fluid at the fluid site in response to the information communicated to the operator.

26. The method of claim 22 further comprising the step of:

controlling in real-time the condition of the fluid in response to the information communicated from the remote facility.

27. The method of claim 26 further comprising the step of:

adding a fluid component to the fluid in response to the signal from the remote location.

28. The method of claim 27 further comprising the step of:

controlling a flow control device connected with the central system and a supply of the fluid component to add the component to the monitored fluid.

29. A system for maintaining the condition of an aqueous metalworking fluid at a metal working location having located thereat a plurality of metalworking machines, a central reservoir containing a volume of the aqueous metalworking fluid sufficient to service the plurality of machines, and means connected to the machines and the reservoir for circulating fluid through the machines and the reservoir, the fluid being made up of components that include a lubricant and water and being used under conditions that will support contaminating biological activity within it, the system comprising:

an oxygen sensor in contact with the circulating fluid operable to generate an oxygen measurement signal responsive to the dissolved oxygen content of the fluid;

a pH sensor in contact with the circulating fluid for generating a pH measurement signal responsive to the hydrogen ion content of the fluid;

a programmed digital computer responsive to the measurement signals and programmed to analyze pH and oxygen content information carried by the measurement signals and to generate an output signal in real time carrying information indicating action to control biological activity within the fluid in response to the analysis; and

means connected in the system and responsive to the output signal for carrying out the indicated action by controlling a parameter of the fluid, different from the sensed pH and oxygen, to control biological activity within the fluid.

30. The system of claim 29 wherein:

the controlling means includes biocidal agent supply means connected to the reservoir or circulating means for adding a biocidal agent to the fluid in response to the output signal.

31. A system for controlling the biological contamination of an aqueous metalworking fluid at a metal working location having located thereat a plurality of metalworking machines, a central reservoir containing a volume of the aqueous metalworking fluid sufficient to service the plurality of machines, and means connected to the machines and the reservoir for circulating fluid through the machines and the reservoir, the fluid being made up of components that include a lubricant and water and being used under conditions that will support contaminating biological activity within it, the system comprising:

means connected in-line with the recirculating fluid for monitoring in real time at least two components of the fluid which have a tendency to vary differently in response to biological activity within the fluid and for producing, in real time, measurement signals responsive to the monitored components;

a programmed computer including means responsive to the measurement signals for analyzing, in real time, information derived from the measurement signals for time varying changes in the monitored components, and for generating in response to the analysis an output signal carrying information representative of the biological activity within the fluid and indicative of the addition of a third component, different from the monitored components, that is effective to directly control the biological activity within the fluid; and

means connected to the system for automatically adding the third component to the fluid in response to the output signal to control the biological activity of the fluid.

32. The system of claim 31 wherein:

the third component is a biocidal agent; and

the third component adding means includes a supply of biocidal agent and means connected to the reservoir or circulating means for adding a biocidal agent from the supply to the fluid in response to the output signal.

33. A system for monitoring and controlling microbiological activity in an aqueous metalworking fluid at a metalworking location having located thereat a plurality of metalworking machines, a central reservoir containing a volume of the aqueous metalworking fluid sufficient to service the plurality of machines, and means connected to the machines and the reservoir for circulating fluid through the machines and the reservoir, the system comprising:

means connected in-line with the circulating fluid at the metal working location for sensing at least two parameters of the fluid thereat including the amount of oxygen dissolved in the fluid;

means connected to the sensing means for producing, in real time, a monitoring signal carrying information responsive to the sensed parameters including amount of dissolved oxygen sensed;

a monitoring facility remote from the metalworking location having located thereat programmed computer means for analyzing information carried by a monitoring signal communicated thereto and for deriving therefrom information relating to the biological activity of a monitored fluid;

a communication link connected between the metal working location and the remote monitoring facility;

means at the metalworking location for transmitting the monitoring signal through the communication link to the remote monitoring facility;

the computer means at the monitoring facility being programmed to generate, in response to the information relating to the biological activity within the fluid, an output signal carrying information relating maintenance of the fluid at the metalworking location to control biological activity therein and

means at the monitoring facility for transmitting the output signal to the metalworking location over the communication link.

34. The system of claim 33 further comprising:

means at the metalworking location for automatically modifying the composition of the monitored fluid in response to the information carried by the output signal.

35. The system of claim 34 wherein the fluid composition modifying means comprises a fluid component source connected to the central system and a fluid flow control device operable in response to the information carried by the output signal to control the introduction of the component from the source into the fluid.

36. The system of claim 33 wherein:

the computer means at the monitoring facility includes means for comparing the monitor signals with stored fluid condition criteria and for generating a predetermined response to an anticipated result of the comparison; and

the transmitting means at the monitoring facility includes means for generating the output signal carrying information for controlling the composition of the fluid in accordance with the predetermined response.

37. A system for monitoring the condition of an aqueous metalworking fluid at plurality of metal working locations for biological activity and for providing information to the locations for the maintenance of the fluid thereat, wherein each metal working location has located thereat a plurality of metalworking machines, a central reservoir containing a volume of the aqueous metalworking fluid sufficient to service the plurality of machines at the location, and means connected to the machines and the reservoir for circulating fluid through the machines at the location and the reservoir, the system comprising:

means at each metalworking location, for sensing in real time and in-line with the circulating fluid, at least two parameters of the metalworking fluid that have a tendency to vary in response to the biological activity within the fluid;

means at each metalworking location for generating a monitoring signal carrying data responsive to variations in the sensed parameters;

a monitoring facility located remote from the metalworking locations and having programmed computer means thereat for analyzing data received from the locations and for generating output signals containing information for the control of the compositions of metalworking fluids in response to the analyses;

means for selectively establishing telephone communications links between each metalworking location and the monitoring facility;

means at each of the metalworking locations for transmitting data from the selected metalworking location to the central monitoring facility over the established communications link; and

means at the monitoring facility for receiving over an established communications link the transmitted data from the selected metalworking location for transmitting over an established communications link the output signal to the selected location containing information for the control of the biological activity of metalworking fluid thereat.