Acoustic transducer assembly for a pressure vessel

• US 8,800,373 B2
• Filed: 02/14/2011
• Issued: 08/12/2014
• Est. Priority Date: 02/14/2011
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Kleven, Lowell A.
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Shah, Samir M
• Application Number:
  US13/026,790
• Publication Number:
  US 20120204650A1
• Time in Patent Office: 1,275 Days
• Field of Search: 735/87, 735/92, 736/22, 736/38, 736/44, 73/46
• US Class Current: 73/644
• CPC Class Codes: F16T 1/48 Monitoring arrangements for inspecting, e.g. flow of steam and steam condensate
• CPC Class Codes: G01N 2291/0234 Metals, e.g. steel
• CPC Class Codes: G01N 2291/0289 Internal structure, e.g. defects, grain size, texture
• CPC Class Codes: G01N 2291/2695 Bottles, containers
• CPC Class Codes: G01N 29/04 Analysing solids using acoustic emission techniques G01N29/14
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: G01N 29/228 related to high temperature conditions
• CPC Class Codes: G01N 29/2462 Probes with waveguides, e.g. SAW devices
• CPC Class Codes: G01N 29/28 providing acoustic coupling , e.g. water impedance matching G10K11/02
• CPC Class Codes: G01N 29/326 compensating for temperature variations

Abstract

A transducer assembly includes an acoustic sensor element and an acoustic waveguide. The acoustic waveguide includes a rotatable acoustic coupler, a tube, and a foot. The foot has a mounting surface that is mountable on a fluid conduit. A circuit assembly couples to acoustic sensor element and provides a diagnostic output.

Claims

1. A transducer assembly for diagnosing acoustic noise from a pressure vessel, comprising:

an acoustic sensor element;

an acoustic waveguide including a rotatable acoustic coupler coupled to the acoustic sensor element, a tube having a first tube end coupled to the rotatable acoustic coupler and a second tube end coupled to a foot portion which extends parallel with a sealed fluid conduit acoustically couplable to the sealed fluid conduit, wherein the foot portion extends parallel with the sealed fluid conduit along an exterior of the sealed fluid conduit; and

a temperature sensor in the foot portion configured to sense a temperature of the conduit;

a circuit assembly coupled to the acoustic sensor element and the temperature sensor, the circuit providing a diagnostic output responsive to an acoustic vibration delivered to the acoustic sensor element through the rotatable acoustic coupler and a temperature output from the temperature sensor, wherein the circuit assembly is rotatable about the rotatable acoustic coupler with respect to the foot portion.

2. The transducer assembly of claim 1 wherein the second tube end has an internal thermowell cavity adjacent the fluid conduit, and the temperature sensor is carried in the internal thermowell cavity and has an output cable that extends through the tube and the first tube end to the circuit assembly.

3. The transducer assembly of claim 2 wherein the temperature sensor is selected from the group of a thermistor and a thermocouple junction.

4. The transducer assembly of claim 1 wherein the circuit assembly provides static temperature compensation.

5. The transducer assembly of claim 1 wherein the circuit assembly provides dynamic temperature compensation.

6. The transducer assembly of claim 1 and further comprising:

an electronic housing that is rotatable relative to the acoustic waveguide; and

an electronic data display that is disposed on the electronic housing and that is aimable by rotation of the electronic housing.

7. The transducer assembly of claim 6 and further comprising frustoconical surfaces on the electronic housing and on the acoustic waveguide, the frustoconical surfaces being rotatable relative to one another.

8. The transducer assembly of claim 7 and further comprising a spring washer that compresses the frustoconical surfaces to control torque as the frustoconical surfaces are rotated relative to one another.

9. The transducer assembly of claim 1 wherein the acoustic sensor element is selected from the group of a piezoelectric force sensor, a capacitive force sensor and a magnetic force sensor.

10. The transducer assembly of claim 1, wherein the acoustic waveguide couples an acoustic vibration from a mounting surface of the foot portion to the acoustic sensor element through the rotatable acoustic coupler.

11. The transducer assembly of claim 10 wherein the acoustic vibration is in the range of 30 kHz to 50 kHz.

12. The transducer assembly of claim 10 further comprising an insulating cap that couples the acoustic vibration from the rotatable acoustic coupler to the acoustic sensor element, the insulating cap providing a rotatable joint between the rotatable acoustic coupler and the acoustic sensor element.

13. The transducer assembly of claim 12, wherein the rotatable acoustic coupler exerts a force on the acoustic sensor element through the insulating cap.

14. The transducer assembly of claim 13, wherein the acoustic sensor element comprises a spring, and compression of the spring presses the insulating cap against the acoustic sensor element.

15. The transducer assembly of claim 10, wherein the second tube end includes a bend that forms the foot portion, and the foot portion is configured to be mounted to the fluid conduit and extend parallel with the fluid conduit.

16. The transducer assembly of claim 1 and further comprising an electronic housing mounting flange that is mounted to the tube and that includes a threaded flange portion adjacent the first tube end.

17. The transducer assembly of claim 16 and further comprising an acoustic sensor support adapter that supports the acoustic sensor element and that includes a threaded support end that engages the threaded flange portion.

18. The transducer assembly of claim 1 wherein the tube comprises a metal tube having an external diameter of less than 11 millimeters.

19. The transducer assembly of claim 18 wherein the tube comprises a tube wall thickness of less than 2.0 millimeter.

20. A method of sensing acoustic energy at a fluid conduit, comprising:

providing an acoustic sensor element;

coupling a first end of a rotatable acoustic coupler to the acoustic sensor element;

coupling a first end of a tube to a second end of the rotatable acoustic coupler;

mounting a foot portion coupled to a second end of the tube to the fluid conduit;

the foot portion extending parallel with the fluid conduit, wherein the foot portion extends parallel with the sealed fluid conduit along an exterior of the sealed fluid conduit;

delivering an acoustic vibration from a mounting surface of the foot portion to the acoustic sensor element through the foot portion, the tube, and the rotatable acoustic coupler;

sensing a temperature of the fluid conduit with a temperature sensor in the foot portion configured to thermally couple to the conduit;

providing a first electrical output representative of the acoustic vibration using the acoustic sensor element

diagnosing a condition of the fluid conduit based upon the first electrical output and the sensed temperature with an electrical circuit; and

rotating the electrical circuitry about the rotatable acoustic coupler to a desired position with respect to the foot portion.

21. The method of claim 20, and further comprising:

shaping the foot to include an internal thermowell cavity adjacent the mounting surface; and

sensing a temperature in the internal thermowell cavity and providing a second electrical output representative of temperature.

22. The method of claim 20 and sensing the acoustic vibration with the acoustic sensor element in the range of 30 kHz to 50 kHz.

23. The method of claim 20 and coupling the rotatable acoustic coupler to the acoustic sensor element through an insulating cap that forms a rotatable joint between the rotatable acoustic coupler and the acoustic sensor element.

24. The method of claim 23 and exerting a force on the acoustic sensor element through the insulating cap using the rotatable acoustic coupler.

25. The method of claim 24, wherein the acoustic sensor element comprises a spring, and exerting a force on the acoustic sensor element through the insulating cap using the rotatable acoustic coupler comprises compressing the spring against the insulating cap.

26. The method of claim 20 and mounting the acoustic sensor element to an acoustic mounting flange and threading the mounting flange.

27. The method of claim 26 and mounting an electronics housing support adapter that includes a threaded end that engages the threading of the mounting flange.

28. The method of claim 20 and forming the tube of metal.

29. The method of claim 20 and bending a second end of the tube to form the foot portion.