Viscosity Measurement Correction for Flow Rate Cross-Sensitivity

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Solution Overview

Problem

Existing methods for determining viscosity using Coriolis mass flowmeters or density measuring devices with vibrating measuring tubes face challenges at high flow rates, where damping fluctuations increase and become sensitive to flow rate rather than viscosity alone.

Innovation Solution

A method that corrects for cross-sensitivity by calculating adjusted damping values based on preliminary measurements, using a correction term derived from the standard deviation of damping fluctuations or flow parameter differences, to isolate viscosity-dependent measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If damping measurements are used to determine viscosity at high flow rates, then viscosity measurement is enabled, but measurement precision deteriorates due to increasing damping fluctuations and cross-sensitivity to flow velocity

Engineering Contradiction:
Improveviscosity measurement precisionVSAvoidmeasurement reliability at high flow rates
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent implements feedback by continuously monitoring the damping behavior at different flow rates and using this information to dynamically adjust and correct viscosity measurements. The system measures damping at multiple flow rates, compares the actual damping behavior against expected patterns, and applies corrections based on the observed deviations, thereby maintaining measurement reliability across the full flow rate range.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies parameter changes by measuring damping at multiple flow rates rather than a single fixed flow rate. By varying the flow rate parameter and observing how damping changes, the system can distinguish between damping caused by viscosity and damping caused by flow velocity effects, enabling accurate viscosity determination even at high flow rates where cross-sensitivity occurs.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If flow velocity increases above critical velocity, then throughput increases, but damping fluctuations increase causing measurement errors

Engineering Contradiction:
Improveflow rateVSAvoiddamping measurement precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing measurements at multiple flow rates before final viscosity determination. The system first measures damping behavior across a range of flow rates, identifies the critical velocity threshold and damping patterns, and uses this preliminary information to correct subsequent viscosity measurements, ensuring accuracy even when operating at high productivities above critical velocity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamics by making the measurement process adaptive to changing flow conditions. Rather than using a fixed measurement approach, the system dynamically adjusts measurement parameters and applies flow-rate-dependent corrections based on real-time observations of damping behavior, allowing accurate viscosity measurement across varying productivity levels.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables reliable viscosity measurement at high flow rates by minimizing the influence of flow rate on damping measurements, ensuring accurate viscosity determination.

Implementation Method 1

damping of the measuring tube oscillations of a Coriolis mass flowmeter or a density meter with an oscillating measuring tube

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

the damping depends on the viscosity of the medium

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Implementation Method 3

Coriolis mass flowmeter

Methodology Applied
Scientific EffectCoriolis force: Coriolis Force

Data Source

PatentEP4022262B1Method and measuring device for determining the viscosity of a medium
Publication Date: 2024.07.10 ENDRESS HAUSER FLOWTEC AG
  • EP4022262B1 patent drawingFigure 1~2
  • EP4022262B1 patent drawingFigure 3~4
  • EP4022262B1 patent drawing

AI summary

A method for determining a target measurement value (X), which comprises a viscosity of a medium or a viscosity-dependent variable based on provisional damping measurement values of an oscillation mode of a measurement tube, comprises: Exciting oscillations of an oscillation mode; detecting a sequence of provisional damping measurement values (110; 210) for the measurement tube oscillation mode; and calculating target measurement values (X) (140; 240); wherein the influence of the cross-sensitivity of the damping for the flow rate of the medium is corrected by determining rectified damping measurement values (130; 230) on the basis of the provisional damping measurement values, which rectified values correspond to damping when the medium is at rest, and determining the target measurement values on the basis of the rectified damping measurement values, or correcting the influence of the cross-sensitivity of the damping for the flow rate of the medium by determining, on the basis of the provisional damping measurement values, provisional intermediate values of a damping-dependent variable (112; 114), determining rectified intermediate values (132; 134) that correspond to the intermediate values when the medium is at rest, and determining the target measurement values (142) on the basis of the rectified intermediate values.