Process diagnostics

• US 7,290,450 B2
• Filed: 07/16/2004
• Issued: 11/06/2007
• Est. Priority Date: 07/18/2003
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Brown, Gregory C., Karschnia, Robert J., Peluso, Marcos
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US10/893,144
• Publication Number:
  US 20050011278A1
• Time in Patent Office: 1,208 Days
• Field of Search: 735/79, 735/92, 735/97, 736/02, 738/612.3, 738/612.2, 732/041.3, 738/614.2, 732/041.8
• US Class Current: 73/579
• CPC Class Codes: G01F 1/666 by detecting noise and sounds generated by the flowing fluid
• CPC Class Codes: G01F 1/7082 using acoustic detecting arrangements
• CPC Class Codes: G01N 2291/014 Resonance or resonant frequency
• CPC Class Codes: G01N 2291/02836 Flow rate, liquid level
• CPC Class Codes: G01N 2291/02872 Pressure
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• 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 29/449 Statistical methods not provided for in G01N29/4409, e.g. averaging, smoothing and interpolation

Abstract

A diagnostic device for use in a industrial process includes monitoring electronics or diagnostic circuitry configured to diagnose or identify a condition or other occurrence in the industrial process. The system can be implemented in a process device such as a flowmeter, and in one example an acoustic flowmeter. A transducer can also be used and a frequency response, such as resonant frequency, can be observed.

Claims

1. A diagnostic device for detecting fouling and corrosion in process equipment comprising:

at least one detector for measuring a frequency response coupled to the process equipment wherein the frequency response is related to fouling or corrosion of the process equipment;

a transducer coupled to a process element and adapted to excite the process element into resonance; and

a diagnostic circuit coupled to the at least one detector and the transducer, the diagnostic circuit adapted to trigger the process element into resonance via a command sent to the transducer and to process the measured frequency response from the at least one detector, the diagnostic circuit adapted to compare the measured frequency response to a stored reference frequency response and to produce a diagnostic signal indicative of health of the process equipment indicative of fouling or corrosion of the process equipment based on a deviation of the measured frequency response from the stored frequency response.

2. The diagnostic device of claim 1 wherein the diagnostic circuitry comprises:

a transformation block adapted to transform the measured frequency response into a process signature; and

a comparator adapted to compare the process signature to a stored reference signature to identify a change.

3. The diagnostic device of claim 1 wherein the transducer comprises:

an acoustic generator coupled to the process equipment and adapted to generate an acoustic signal within the process equipment.

4. The diagnostic device of claim 3 wherein the acoustic generator is coupled to the diagnostic circuit, wherein the diagnostic circuit is adapted to initiate generation of an acoustic signal at a particular frequency by the acoustic generator.

5. The diagnostic device of claim 1 and further comprising:

fixed equipment coupled to a pipe section, the fixed equipment generating process noise as process fluid flows through the fixed equipment;

wherein the change is indicative of corrosion or fouling of the fixed equipment.

6. The diagnostic device of claim 1 and further comprising:

a non-volatile memory buffer adapted to store the stored frequency response, the stored frequency response comprising a transformed process noise signal of process fluid flowing through an industrial process when components of the industrial process are functioning properly.

7. The diagnostic device of claim 1 wherein the frequency response comprises:

a signal composed of a plurality of frequencies.

8. The diagnostic device of claim 1 wherein the diagnostic circuitry comprises:

a neural network.

9. The diagnostic device of claim 1 and further comprising:

an external input or local operator interface for configuring the diagnostic circuit.

10. The diagnostic device of claim 1 wherein the process equipment is configured to couple to a heat exchanger.

11. The diagnostic device of claim 1 including a temperature sensor.

12. The diagnostic device of claim 1 including a structure to introduce vortexes in a process fluid.

13. The diagnostic device of claim 1 wherein the deviation of the measured frequency response is indicative of a mass change of the process equipment.

14. The diagnostic device of claim 13 wherein the mass change is a loss of mass indicative of corrosion.

15. The diagnostic device of claim 13 wherein the mass change is a gain of mass indicative of build up.

16. The diagnostic device of claim 1 wherein the process equipment comprises:

a thermowell with a temperature sensor for measuring a process temperature of a process fluid.

17. The diagnostic device of claim 1 wherein the process equipment comprises:

a pipe section.

18. The diagnostic device of claim 1 wherein the process equipment comprises:

an obstruction extending into a fluid flow.