Diagnostics of impulse piping in an industrial process

• US 7,523,667 B2
• Filed: 12/23/2003
• Issued: 04/28/2009
• Est. Priority Date: 12/23/2003
• Status: Expired due to Term

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Schumacher, Mark S., Brown, Gregory C.
• Primary Examiner(s): Williams; Hezron E.
• Assistant Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US10/744,809
• Publication Number:
  US 20050132808A1
• Time in Patent Office: 1,953 Days
• Field of Search: 735/92, 736/44, 738/612.3, 73/11.6, 738/613.55, 738/613.56, 738/613.57, 738/612.2, 73/405.A, 73/405.R, 73/405, 736/11, 702104-105, 702/45, 702/183, 702/55, 702/69, 702/191, 702/195, 340/606
• US Class Current: 73/592
• CPC Class Codes: G01F 25/10 of flowmeters
• CPC Class Codes: G01L 19/0015 using switching means
• CPC Class Codes: G01N 2291/2634 cylindrical from outside
• CPC Class Codes: G01N 29/12 by measuring frequency or resonance of acoustic waves measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00

Abstract

Diagnosing operation of an impulse piping line in an industrial process is provided. A vibration source transmits a vibration signal through the piping and a vibration signal receiver receives the vibration signal. The operation of the impulse piping line is diagnosed, such as failure or impending failures, based upon the received vibration signal.

Claims

1. A process variable transmitter for sensing a process variable of an industrial process, comprising:

a process variable sensor configured to sense the process variable;

an impulse piping line configured to couple the process variable sensor to a process fluid of an industrial process;

a vibration signal source configured to transmit an acoustic vibration signal into the industrial process and through the impulse piping line, the acoustic vibration signal having an acoustic signature, the vibration signal source providing the acoustic vibration signal in response to an input;

a vibration signal receiver acoustically coupled to the impulse piping configured to receive the vibration signal from the impulse piping line wherein the vibration signal is generated by the vibration signal source; and

diagnostic circuitry configured to provide the input to the vibration signal source and responsively diagnose condition of the impulse piping line based upon the received vibration signal.

2. The apparatus of claim 1 wherein the diagnostic circuitry is further configured to monitor background noise.

3. The apparatus of claim 1 wherein the diagnostic circuitry compares monitored background noise with a stored reference noise signature to identify failure or pending failure of process equipment.

4. The apparatus of claim 1 wherein a frequency of the vibration signal is adjusted to change a signal to noise ratio.

5. The apparatus of claim 1 wherein the diagnostic circuitry is configured to diagnose variations in impulse piping which forms a filled capillary leg of a level measurement device.

6. The apparatus of claim 1 wherein the diagnostic circuitry includes a memory containing a spectral profile of a received vibration signal.

7. The apparatus of claim 1 wherein the diagnostic circuitry comprises comparing the received vibration signal to a reference.

8. The apparatus of claim 1 wherein the vibration signal source and signal receiver are formed by a transducer.

9. The apparatus of claim 1 wherein the vibration signal comprises a noise signal.

10. The apparatus of claim 1 wherein the vibration signal has a frequency of less than about 20 Hz.

11. The apparatus of claim 1 wherein the vibration signal source and vibration signal receiver are coupled to a process coupling.

12. The apparatus of claim 11 wherein the process coupling comprises a flange.

13. The apparatus of claim 12 wherein the vibration signal source and vibration signal receiver are inserted through and disposed within an opening in the flange.

14. The apparatus of claim 1 wherein the vibration signal source is configured to direct the transmitted vibration signal along a length of the impulse piping line.

15. The apparatus of claim 1 wherein the sensed process variable comprises flow of process fluid.

16. The apparatus of claim 1 wherein the sensed process variable comprises pressure of process fluid.

17. The apparatus of claim 1 wherein the sensed process variable comprises level of process fluid.

18. The apparatus of claim 1 includes a transmitter housing and the vibration signal source and vibration signal receiver couple to the diagnostic circuitry through an opening in the transmitter housing.

19. The apparatus of claim 1 wherein including output circuitry configured to couple to a two-wire process control loop.

20. The apparatus of claim 19 wherein circuitry is configured to be completely powered with power received from the process control loop.

21. The apparatus of claim 1 wherein the diagnostic circuitry is configured to diagnose plugging of the impulse piping line.

22. The apparatus of claim 1 wherein the diagnostic circuitry is configured to diagnose loss of fill fluid in the impulse piping line.

23. The apparatus of claim 1 wherein the diagnostic circuitry is configured to diagnose variations in impulse piping line forming a wet leg of a level measurement device.

24. The apparatus of claim 1 wherein the diagnostic circuitry is configured to diagnose variations in impulse piping line forming a dry leg of a level measurement device.

25. The apparatus of claim 1 wherein the diagnostic circuitry performs a self diagnostic based upon the received vibration signal.

26. The apparatus of claim 1 wherein the vibration signal source and vibration signal receiver comprise a piezoelectric transducer.

27. A method of sensing a process variable in an industrial process, comprising:

coupling a process variable sensor to the process fluid of the industrial process using impulse piping;

sensing a process variable of the process fluid using the process variable sensor;

controlling a vibration signal source with an input to the vibration signal source to generate a desired acoustic vibration signal having an acoustic signature response to the input and sending the vibration signal along the impulse piping;

receiving the vibration signal from the impulse piping line with a sensor acoustically coupled to the impulse piping; and

diagnosing condition of the impulse piping based upon the received vibration signal.

28. The method of claim 27 wherein the diagnosing includes retrieving a spectral profile of a received vibration signal.

29. The method of claim 27 wherein the diagnosing comprises comparing the received vibration signal to a reference.

30. The method of claim 27 wherein the vibration signal comprises a noise signal.

31. The method of claim 27 wherein the vibration signal has a frequency of less than about 20 Hz.

32. The method of claim 27 including coupling the vibration signal to a process coupling.

33. The method of claim 32 wherein the process coupling comprises providing a flange.

34. The method of claim 27 wherein process variable sensor comprises a pressure sensor.

35. The method of claim 27 including directing the vibration signal along a length of the impulse piping.

36. The method of claim 27 including transmitting diagnostic data on a two-wire process control loop.

37. The method of claim 27 including diagnosing plugging of the impulse piping.

38. The method of claim 27 including diagnosing loss of fill fluid in the impulse piping.

39. The method of claim 27 including diagnosing variations in impulse piping forming a wet leg of a level measurement device.

40. The method of claim 27 including diagnosing variations in impulse piping forming a dry leg of a level measurement device.

41. The method of claim 27 including performing a self diagnostic based upon the received vibration signal.