Entrained fluid detection diagnostic

Patent metadata

Field	Value
Publication number	US-2017089743-A1
Application number	US-201514863734-A
Country	US
Kind code	A1
Filing date	Sep 24, 2015
Priority date	Sep 24, 2015
Publication date	Mar 30, 2017
Grant date	—

Abstract

A magnetic flowmeter includes at least one coil configured to generate a magnetic field within a process fluid flow. A pair of electrodes is configured to detect an electromotive force within the flowing process fluid in response to the magnetic field. Measurement circuitry is coupled to the pair of electrodes and is configured to provide an indication of the detected electromotive force. A processor is coupled to the measurement circuitry and configured to receive the indication of the detected electromotive force and determine a flow-related output based on the detected electromotive force. A diagnostics component is configured to analyze a number of successive parameters of the magnetic flowmeter in order to provide an indication of a detected entrained fluid.

First claim

What is claimed is:

1 . A magnetic flowmeter, comprising:
at least one coil configured to generate a magnetic field within a process fluid flow; a pair of electrodes configured to detect an electromotive force within the flowing process fluid in response to the magnetic field; measurement circuitry coupled to the pair of electrodes and configured to provide an indication of the detected electromotive force; a processor coupled to the measurement circuitry and configured to receive the indication of the detected electromotive force and determine a flow-related output based on the detected electromotive force; and a diagnostics component configured to analyze a number of successive parameters of the magnetic flowmeter in order to provide an indication of a detected entrained fluid.

2 . The magnetic flowmeter of claim 1 , further comprising a communications module configured to couple to a wireless process communication loop.

3 . The magnetic flowmeter of claim 1 , wherein the successive parameters include at least one of:
a flow value; a differential electrode voltage; a common mode electrode voltage; an empty pipe value; a signal to noise ratio; an empty pipe phase angle; and an empty pipe magnitude.

4 . The magnetic flowmeter of claim 1 , wherein the diagnostic component is configured to calculate a standard deviation of the successive parameters.

5 . The magnetic flowmeter of claim 1 , wherein the diagnostic component is configured to calculate a coefficient of variation of the successive parameters.

6 . The magnetic flowmeter of claim 1 , wherein the provided indication is an alert.

7 . The magnetic flowmeter of claim 1 , wherein the provided indication includes an identification of the entrained fluid.

8 . A method of detecting an entrained fluid with a magnetic flowmeter, the method comprising:
obtaining a plurality of process variable signal measurements; calculating a statistic based, at least in part, on the plurality of process variable signal measurements; comparing the calculated statistic to a pre-determined threshold; determining, based on the comparison, whether an entrained fluid is present; and providing an indication that an entrained fluid is present.

9 . The method of claim 8 , and further comprising:
detecting, based on the comparison, that the entrained fluid comprises entrained gas, and providing an indication that entrained gas is present.

10 . The method of claim 8 , and further comprising:
detecting, based on the comparison, that the entrained fluid comprises entrained oil, and providing an indication that entrained oil is present.

11 . The method of claim 8 , wherein the pre-determined threshold is based at least in part on a previously-measured value stored within a memory component of the magnetic flowmeter.

12 . The method of claim 8 , and further comprising:
displaying at least one of the process variable signal measurement and the calculated statistic on an external display.

13 . The method of claim 8 , wherein the provided indication comprises a visual alert.

14 . The method of claim 8 , wherein the provided indication comprises an audible alert. audible alert

15 . The method of claim 8 , wherein the process variable signal measurement includes measurement of at least one of:
a flow value; a differential electrode voltage; a common mode electrode voltage; an empty pipe value; a signal to noise ratio; an empty pipe phase angle; and an empty pipe magnitude.

16 . The method of claim 8 , wherein the calculated statistic is standard deviation.

17 . The method of claim 8 , wherein the calculated statistic is a coefficient of variation.

18 . A device for detecting an entrained fluid within a process stream, comprising:
a signal receiving component configured to receive a sensor signal indicative of a characteristic of a process stream, wherein the sensor signal is generated by a sensor associated with a magnetic flowmeter coupled to the process stream; a diagnostics component configured to analyze the received sensor signal and calculate a statistic based at least in part on the received sensor signal; and a processor component configured to determine, based at least in part on the calculated statistic, that an entrained fluid is present within the process stream and provide an indication of a detected entrained fluid.

19 . The method of claim 18 , wherein the device is a diagnostic component within the magnetic flowmeter.

20 . The method of claim 18 , wherein the device is communicably coupled to the magnetic flowmeter over a process communication loop.

Assignees

• Rosemount Inc

Inventors

• Machuca Michael P
• Smith Joseph A
• Ball Trever J
• Foss Scot R

Classifications

• G01F1/74

  Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid · CPC title

• G01F1/58 Primary

  by electromagnetic flowmeters · CPC title

• G01F15/08

  Air or gas separators in combination with liquid meters; Liquid separators in combination with gas-meters · CPC title

• G01F1/588 Primary

  combined constructions of electrodes, coils or magnetic circuits, accessories therefor · CPC title

• G01F1/60 Primary

  Circuits therefor · CPC title