Alternating magnetic field flow meters

Patent metadata

Field	Value
Publication number	US-10330511-B2
Application number	US-201715630736-A
Country	US
Kind code	B2
Filing date	Jun 22, 2017
Priority date	Jun 22, 2017
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

Methods, apparatus, and systems for flow measurements by alternating magnetic fields are provided. An example alternating magnetic field flowmeter includes a magnetic token movable within a conduit for guiding a fluid flow (conductive or non-conductive) along a flow path, a magnetic field generator configured to generate alternating magnetic fields within the conduit to move the magnetic token along the flow path with a first flow velocity and opposite to the flow path with a second flow velocity, a detector configured to measure respective first and second electrical signals responsive to the alternating magnetic fields, the first and second electrical signals associated with the first and second flow velocities, and a processor configured to determine a flow rate of the fluid based on the first and second electrical signals. The alternating magnetic field flowmeter can include a calibrator configured to manually or automatically calibrate the flow rate with a correction factor.

First claim

What is claimed is:

1. An alternating magnetic field flow meter comprising:
a magnetic token movable within a conduit operable to guide a fluid flow along a flow path;
a magnetic field generator configured to:
generate a first magnetic field to move the magnetic token along a direction of the flow path, and
generate a second magnetic field to move the magnetic token opposite to the direction of the flow path; and

a detector configured to detect:
a first electrical signal associated with the movement of the magnetic token along the direction of the flow path, and
a second electrical signal associated with the movement of the magnetic token opposite to the direction of the flow path,

wherein a flow rate of the fluid flow is determined based on the detected first electrical signal and the detected second electrical signal.

2. The alternating magnetic field flow meter of claim 1 , wherein the detector comprises a piezoelectric sensor including a first surface coupled to an inlet of the conduit and a second surface coupled to an outlet of the conduit, and
wherein the detector is configured to:
detect a first voltage signal when the magnetic token is moved to deform the second surface along the direction of the flow path, the first electrical signal including the first voltage signal; and
detect a second voltage signal when the magnetic token is moved to deform the first surface opposite to the direction of the flow path, the second electrical signal including the second voltage signal.

3. The alternating magnetic field flow meter of claim 1 , wherein the magnetic field generator comprises an electromagnetic coil and is configured to:
generate the first magnetic field by inputting a current into the electromagnetic coil, and
generate the second magnetic field by reversing a polarity of the current into the electromagnetic coil.

4. The alternating magnetic field flow meter of claim 3 , wherein the detector comprises a current detector with a first electrode coupled to a first end of the electromagnetic coil and a second electrode coupled to a second end of the electromagnetic coil, and
wherein the magnetic field generator is configured to:
generate the first magnetic field to move the magnetic token along the direction of the flow path for a first period of time and then de-energize the first magnetic field, such that the current detector receives a first current signal in response to the magnetic token moving in the electromagnetic coil without the first magnetic field and along the direction of flow path, the first electrical signal including the first current signal, and
generate the second magnetic field to move the magnetic token opposite to the direction of the flow path for a second period of time and then de-energize the second magnetic field, such that the current detector receives a second current signal in response to the magnetic token moving in the electromagnetic coil without the second magnetic field and opposite to the direction of flow path, the second electrical signal including the second voltage signal.

5. The alternating magnetic field flow meter of claim 1 , wherein the magnetic field generator is configured to alternately generate the first magnetic field and the second magnetic field,
wherein the detector is configured to detect a plurality of first electrical signals and corresponding second electrical signals when the magnetic token is moved within the conduit by the alternating first magnetic field and second magnetic field, and
wherein the flow rate of the fluid flow is determined based on respective differences between the first electrical signals and corresponding second electrical signals.

6. The alternating magnetic field flow meter of claim 1 , configured to:
determine a difference between the first electrical signal and the second electrical signal; and
determine the flow rate of the fluid flow based on the determined difference and associations between differences of electrical signals and respective flow rates.

7. The alternating magnetic field flow meter of claim 1 , wherein the fluid flow comprises at least one of a conductive material or a non-conductive material.

8. The alternating magnetic field flow meter of claim 1 , further comprising a calibrator configured to automatically calibrate the flow rate with a correction factor.

9. The alternating magnetic field flow meter of claim 8 , wherein the correction factor is obtained based on a contaminant distribution pattern for the fluid flow and associations between fluid flows with known contaminant distribution patterns and corresponding correction factors.

10. The alternating magnetic field flow meter of claim 8 , wherein the calibrator is configured to generate the correction factor based on a predicted contaminant distribution pattern for the fluid flow and accumulated calibration information including contaminant distribution patterns and associated accuracy variances of flow meters.

11. A method of measuring a flow rate of a fluid flow by an alternating magnetic field flow meter, the method comprising:
generating a first magnetic field to move a magnetic token along a direction of a flow path of a fluid flowing through a conduit;
detecting a first electrical signal based on the movement of the magnetic token along the direction of the flow path;
generating a second magnetic field to move the magnetic token opposite to the direction of the flow path;
detecting a second electrical signal based on the movement of the magnetic token opposite to the direction of the flow path; and
determining the flow rate of the fluid flow based on the detected first electrical signal and the detected second electrical signal.

12. The method of claim 11 , wherein detecting a first electrical signal comprises detecting a first voltage signal when the magnetic token is moved to deform a first surface of a piezoelectric sensor coupled to an outlet of the conduit, and
wherein detecting a second electrical signal comprises detecting a second voltage signal when the magnetic token is moved to deform a second surface of the piezoelectric sensor coupled to an inlet of the conduit.

13. The method of claim 11 , wherein generating the first magnetic field comprises inputting a current into an electromagnetic coil, and generating the second magnetic field comprises reversing a polarity of the current into the electromagnetic coil.

14. The method of claim 13 , further comprising:
after generating the first magnetic field for a first period of time, de-energizing the first magnetic field, such that the magnetic token moves in the electromagnetic coil without the first magnetic field and along the direction of flow path to generate a first current signal, wherein detecting a first electrical signal comprises detecting the first current signal; and
after generating the second magnetic field for a second period of time, de-energizing the second magnetic field, such that the magnetic token moves in the electromagnetic coil without the second magnetic field and opposite to the direction of flow path to generate a second current signal, wherein detecting a second electrical signal comprises detecting the second current signal.

15. The method of claim 11 , wherein determining the flow rate of the fluid flow comprises:
calculating a difference between the first electrical signal and the second electrical signal; and
determining the flow rate based on the calculated difference and associations between differences of electrical signals and respective flow rates.

16. The method of claim 11 , comprising:
alternate

Assignees

• Saudi Arabian Oil Co

Inventors

• Alkhabbaz Fouad M
• Al-Maatoug Maatoug
• Al-Awami Luay H

Classifications

• G01F1/58

  by electromagnetic flowmeters · CPC title

• G01F1/704

  using marked regions or existing inhomogeneities within the fluid stream, e.g. statistically occurring variations in a fluid parameter (G01F1/76, G01F25/00 take precedence) · CPC title

• G01F1/582

  without electrodes · CPC title

• G01F1/586

  constructions of coils, magnetic circuits, accessories therefor (G01F1/582 takes precedence; magnet; inductances; transformers; selection of materials for their magnetic properties per se H01F) · CPC title

• G01F1/24

  with magnetic or electric coupling to the indicating device · CPC title