Correcting for two-phase flow in a digital flowmeter

• US 20040206189A1
• Filed: 04/26/2004
• Published: 10/21/2004
• Est. Priority Date: 03/23/2000
• Status: Active Grant

• Current Assignee: Schneider Electric Systems USA, Inc. (Schneider Electric SE)
• Original Assignee: Invensys Systems Incorporated (Invensys PLC)
• Inventors: Henry, Manus P., De La Fuente, Maria Jesus
• Granted Patent: US 6,981,424 B2
• Time in Patent Office: Days
• US Class Current: 73/861.356
• CPC Class Codes: G01F 1/74 Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid
• CPC Class Codes: G01F 1/8431 electronic circuits
• CPC Class Codes: G01F 1/8436 signal processing
• CPC Class Codes: G01F 1/8486 with multiple measuring conduits
• CPC Class Codes: G01F 15/024 involving digital counting

Abstract

A flowmeter is disclosed. The flowmeter includes a vibratable conduit, and a driver connected to the conduit that is operable to impart motion to the conduit. A sensor is connected to the conduit and is operable to sense the motion of the conduit and generate a sensor signal. A controller is connected to receive the sensor signal. The controller is operable to detect a single-phase flow condition and process the sensor signal using a first process during the single-phase flow condition to generate a validated mass-flow measurement. The controller is also operable to detect a two-phase flow condition and process the sensor signal using a second process during the two-phase flow condition to generate the validated mass-flow measurement.

Claims

1. A flowmeter controller comprising:

an input module operable to receive sensor signals from a sensor connected to a vibratable flowtube, the sensor signals related to a mass flow through the flowtube, wherein the mass flow includes a first material having a first phase and a second material having a second phase;

a signal processing system operable to receive the sensor signal, determine sensor signal characteristics, and output drive signal characteristics for a drive signal applied to the flowtube, the drive signal characteristics including a drive gain necessary to maintain oscillation of the flowtube during the mass flow;

a measurement system operable to determine an actual flow condition of the mass flow, based on an apparent flow condition derived from the sensor signal characteristics; and

an output module operable to output the drive signal.