INDUSTRIAL PROCESS DEVICE UTILIZING PIEZOELECTRIC TRANSDUCER

• US 20090260438A1
• Filed: 04/22/2008
• Published: 10/22/2009
• Est. Priority Date: 04/22/2008
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Hedtke, Robert C.
• Granted Patent: US 8,250,924 B2
• Time in Patent Office: Days
• US Class Current: 73/579
• CPC Class Codes: G01H 11/08 using piezoelectric devices
• CPC Class Codes: G01L 9/00 Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements G01L11/004 takes precedence; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means measuring differences of two or more pressure values G01L13/00; measuring two or more pressure values simultaneously G01L15/00
• CPC Class Codes: G01L 9/0008 using vibrations
• CPC Class Codes: G01L 9/0022 of a piezoelectric element
• CPC Class Codes: G05B 11/01 electric

Abstract

A process device for coupling to an industrial process for use in monitoring or controlling the process includes a device housing configured to physically couple to the industrial process. A process variable sensor is configured to measure a process variable and measurement circuitry coupled to the process variable sensor provides an output related to the sensed process variable. A piezoelectric transducer provides an electrical output related to pressure pulsations in the industrial process. Electrical circuitry in the housing includes an input configured to receive the electrical output from the piezoelectric sensor.

Claims

1. A process device for coupling to an industrial process for use in monitoring or controlling the process, comprising:

a device housing configured to physically couple to the industrial process;

a process variable sensor configured to measure a process variable;

measurement circuitry coupled to the process variable sensor having an output related to the sensed process variable;

a piezoelectric transducer having an electrical output related to pressure pulsations in the industrial process; and

electrical circuitry in the housing having an input configured to receive the electrical output from the piezoelectric sensor, the electrical output used to provide power to the process device.

2. The apparatus of claim 1 wherein the electrical circuitry is configured to diagnose operation of the industrial process based upon the electrical output.

3. The apparatus of claim 2 including an analog to digital converter having a digital output related to digitize the electrical output.

4. The apparatus of claim 2 including a microcontroller configured to perform diagnostics.

5. The apparatus of claim 2 wherein the diagnostics are based upon an amplitude of pulsations in the industrial process.

6. The apparatus of claim 2 wherein the diagnostics are based upon a frequency of pulsations in the industrial process,

7. The apparatus of claim 2 wherein the diagnostics are based upon a signature in the pulsations in the industrial process.

8. The apparatus of claim 2 wherein the electrical circuitry provides a diagnostic output based upon the pulsations and data stored in a memory.

9. The apparatus of claim 1 wherein the piezoelectric transducer is configured to receive a control signal which causes movement of the piezoelectric transducer.

10. The apparatus of claim 1 wherein movement of the piezoelectric transducer induces pressure pulsations in the process fluid which are sensed by the process variable sensor, the electrical circuitry further configured to diagnose transmitter operation based upon the sensed pressure pulsations.

11. The apparatus of claim 1 wherein the electrical circuitry includes power storage circuitry configured to store power from the piezoelectric transducer.

12. The apparatus of claim 11 wherein the power storage circuitry comprises a capacitor.

13. The apparatus of claim 12 wherein the capacitor comprises a supercapacitor.

14. The apparatus of claim 1 wherein the piezoelectric transducer is mounted in the housing of the process device.

15. The apparatus of claim 1 wherein the piezoelectric transducer is mounted in a sensor module of the process device.

16. The apparatus of claim 1 wherein the piezoelectric transducer is carried on a mounting flange used to couple the process device to the industrial process.

17. The apparatus of claim 1 wherein the piezoelectric transducer is positioned at a location which is spaced apart from the device housing.

18. The apparatus of claim 1 wherein the piezoelectric transducer couples to the process fluid through a resonant pipe.

19. The apparatus of claim 1 wherein the piezoelectric transducer couples to process fluid through a diaphragm.

20. A method for sensing pulsations in a process device coupled to an industrial process of the type used in monitoring a process variable of industrial process, the method comprising:

physically coupling a piezoelectric transducer to the industrial process;

receiving pressure pulsations from the industrial process through the physical coupling;

sensing a process variable with a process variable sensor;

providing a process variable output based upon the sensed process variable;

coupling the pressure pulsations to the piezoelectric transducer and providing an electrical output from the piezoelectric transducer in response to the pressure pulsations; and

providing the electrical output to electrical circuitry of the process device, the electrical output for providing power to the electrical circuitry.

21. The method of claim 20 including diagnosing operation of the industrial process based upon the electrical output.

22. The method of claim 20 including digitizing the electrical output.

23. The method of claim 21 wherein the diagnosing is based upon an amplitude of pulsations in the industrial process.

24. The method of claim 21 wherein the diagnosing is based upon a frequency of pulsations in the industrial process.

25. The method of claim 21 wherein the diagnosing is based upon a signature in the pulsations in the industrial process.

26. The method of claim 21 including providing a diagnostic output based upon the pulsations and data stored in a memory.

27. The method of claim 20 including providing a control signal to the piezoelectric transducer which causes movement of the piezoelectric transducer.

28. The method of claim 27 wherein the movement of the piezoelectric transducer induces pressure pulsations in the process fluid and sensing the pressure pulsations with the process variable sensor, the method further including diagnosing transmitter operation based upon the sensed pressure pulsations.

29. The method of claim 20 wherein the piezoelectric transducer is mounted in the housing of the process device.

30. The method of claim 20 wherein the piezoelectric transducer is mounted in a sensor module of the process device.

31. The method of claim 20 wherein the piezoelectric transducer is carried on a mounting flange used to couple the process device to the industrial process.

32. The method of claim 20 wherein the piezoelectric transducer is positioned at a location which is spaced apart from the device housing.

33. The method of claim 20 wherein the piezoelectric transducer couples to process fluid through a resonant pipe.

34. The method of claim 20 wherein the piezoelectric transducer couples to process fluid through a diaphragm.