Coriolis Flow Meter and Method for Determining Flow Characteristics

• US 20080184813A1
• Filed: 03/29/2005
• Published: 08/07/2008
• Est. Priority Date: 03/29/2005
• Status: Active Grant

• Current Assignee: Micro Motion Incorporated (Emerson Electric Company)
• Original Assignee: Micro Motion Incorporated (Emerson Electric Company)
• Inventors: Duffill, Graeme Ralph, Patten, Andrew T., Henrot, Denis M.
• Granted Patent: US 7,716,995 B2
• Time in Patent Office: Days
• US Class Current: 73/861.355
• CPC Class Codes: G01F 1/8413 means for influencing the flowmeter's motional or vibrational behaviour, e.g., conduit support or fixing means, or conduit attachments
• CPC Class Codes: G01F 1/8436 signal processing
• CPC Class Codes: G01F 1/8477 with multiple measuring conduits
• CPC Class Codes: G01F 15/022 using electrical means
• CPC Class Codes: G01N 11/16 by measuring damping effect upon oscillatory body
• CPC Class Codes: G01N 2009/006 vibrating tube, tuning fork

Abstract

A Coriolis flow meter (5) is provided according to an embodiment of the invention. The meter (5) includes one or more flow conduits (103), at least two pickoff sensors (105, 105′) affixed to the one or more flow conduits (103), a driver (104) configured to vibrate the one or more flow conduits (103), and meter electronics (20) coupled to the at least two pickoff sensors (105, 105′) and to the driver (104). The meter electronics (20) vibrate the one or more flow conduits (103) of the flow meter (5) with a first vibration frequency and in a first out-of-phase bending mode, measure a first vibrational response, with the first vibrational response being generated in response to the first vibration frequency, vibrate the one or more flow conduits (103) with at least a second vibration frequency and in the first out-of-phase bending mode, measure a second vibrational response, and determine at least a mass flow rate and a viscosity using the first and second vibrational responses.

Claims

1. A Coriolis flow meter (5) comprising one or more flow conduits (103), at least two pickoff sensors (105, 105′

) affixed to the one or more flow conduits (103), and a driver (104) configured to vibrate the one or more flow conduits (103), with the Coriolis flow meter (5) being characterized by;

meter electronics (20) coupled to the at least two pickoff sensors (105, 105′

) and to the driver (104), with the meter electronics (20) being configured to vibrate the one or more flow conduits (103) of the flow meter with a first vibration frequency and in a first out-of-phase bending mode, measure a first vibrational response of the one or more flow conduits (103), with the first vibrational response being generated in response to the first vibration frequency, vibrate the one or more flow conduits (103) with at least a second vibration frequency and in the first out-of-phase bending mode, measure a second vibrational response, with the second vibrational response being generated in response to the second vibration frequency, and determine at least a mass flow rate and a viscosity using the first vibrational response and the second vibrational response.

2. The Coriolis flow meter (5) of claim 1, with the determining further comprising determining a density.

3. The Coriolis flow meter (5) of claim 1, with the determining further comprising determining a shear rate.

4. The Coriolis flow meter (5) of claim 1, with the determining further comprising determining a Reynolds number.

5. The Coriolis flow meter (5) of claim 1, with the determining further comprising determining a velocity of sound (VOS).

6. The Coriolis flow meter (5) of claim 1, with the determining further comprising determining a pressure.

7. The Coriolis flow meter (5) of claim 1, with the viscosity comprising a kinematic viscosity.

8. The Coriolis flow meter (5) of claim 1, with the viscosity comprising a dynamic viscosity.

9. The Coriolis flow meter (5) of claim 1, further comprising jumping between the first vibration frequency and the second vibration frequency.

10. The Coriolis flow meter (5) of claim 1, further comprising substantially simultaneously vibrating the one or more flow conduits (103) with the first vibration frequency and the second vibration frequency.

11. The Coriolis flow meter (5) of claim 1, further comprising sweeping between the first vibration frequency and the second vibration frequency over a predetermined sweep time period.

12. The Coriolis flow meter (5) of claim 1, with the first vibration frequency and the second vibration frequency being substantially equally spaced above and below a fundamental frequency of the one or more flow conduits (103).

13. The Coriolis flow meter (5) of claim 1, with the one or more flow conduits (103) comprising two, substantially U-shaped flow conduits.

14. A method for determining flow characteristics in a Coriolis flow meter, comprising vibrating one or more flow conduits of the flow meter with a first vibration frequency and in a first out-of-phase bending mode and measuring a first vibrational response of the one or more flow conduits, with the first vibrational response being generated in response to the first vibration frequency, with the method being characterized by:

vibrating the one or more flow conduits with at least a second vibration frequency and in the first out-of-phase bending mode;

measuring a second vibrational response, with the second vibrational response being generated in response to the second vibration frequency; and

determining at least a mass flow rate and a viscosity of the flow medium using the first vibrational response and the second vibrational response.

15. The method of claim 14, with the determining further comprising determining a density.

16. The method of claim 14, with the determining further comprising determining a shear rate.

17. The method of claim 14, with the determining further comprising determining a Reynolds number.

18. The method of claim 14, with the determining further comprising determining a velocity of sound (VOS).

19. The method of claim 14, with the determining further comprising determining a pressure.

20. The method of claim 14, with the viscosity comprising a kinematic viscosity.

21. The method of claim 14, with the viscosity comprising a dynamic viscosity.

22. The method of claim 14, further comprising jumping between the first vibration frequency and the second vibration frequency.

23. The method of claim 14, further comprising substantially simultaneously vibrating the one or more flow conduits with the first vibration frequency and the second vibration frequency.

24. The method of claim 14, further comprising sweeping between the first vibration frequency and the second vibration frequency over a predetermined sweep time period.

25. The method of claim 14, with the first vibration frequency and the second vibration frequency being substantially equally spaced above and below a fundamental frequency of the one or more flow conduits.

26. A Coriolis flow meter software product for determining flow characteristics in a Coriolis flow meter, comprising a control software configured to direct a processing system to vibrate one or more flow conduits of the flow meter with a first vibration frequency and in a first out-of-phase bending mode, measure a first vibrational response of the one or more flow conduits, with the first vibrational response being generated in response to the first vibration frequency, and a storage system that stores the control software, with the software product being characterized by:

the control software being further configured to direct the processing system to vibrate the one or more flow conduits with at least a second vibration frequency and in the first out-of-phase bending mode, measure a second vibrational response, with the second vibrational response being generated in response to the second vibration frequency, and determine at least a mass flow rate and one or more flow characteristics using the first vibrational response and the second vibrational response.

27. The software product of claim 26, with the determining further comprising determining at least a density and a viscosity of the flow medium.

28. The software product of claim 26, with the determining further comprising determining a shear rate.

29. The software product of claim 26, with the determining further comprising determining a Reynolds number.

30. The software product of claim 26, with the determining further comprising determining a velocity of sound (VOS).

31. The software product of claim 26, with the determining further comprising determining a pressure.

32. The software product of claim 26, with the viscosity comprising a kinematic viscosity.

33. The software product of claim 26, with the viscosity comprising a dynamic viscosity.

34. The software product of claim 26, further comprising jumping between the first vibration frequency and the second vibration frequency.

35. The software product of claim 26, further comprising substantially simultaneously vibrating the one or more flow conduits with the first vibration frequency and the second vibration frequency.

36. The software product of claim 26, further comprising sweeping between the first vibration frequency and the second vibration frequency over a predetermined sweep time period.

37. The software product of claim 26, with the first vibration frequency and the second vibration frequency being substantially equally spaced above and below a fundamental frequency of the one or more flow conduits.