Coriolis Flow Meter Sensor Array for Pressure-Insensitive Mass Flow

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing Coriolis mass flow measuring systems face challenges in achieving high precision for mass flow and pressure measurements, especially when pressure fluctuations occur, often requiring additional sensors and modified exciter arrangements, which increase complexity and calibration efforts.

Innovation Solution

A compact Coriolis mass flow rate measuring system with a curved measuring tube that includes multiple vibration sensors spaced apart from the exciter, allowing for the generation of primary signals that are less influenced by static pressure, and an evaluation circuit that processes these signals to calculate accurate mass flow and pressure values using phase differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional sensors and modified exciter arrangements are used to achieve high precision mass flow and pressure measurements, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvemass flow measurement precisionVSAvoidsensor arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the existing vibration sensors serve dual functions: they continue to detect mass flow information while simultaneously providing pressure measurement capability. By evaluating the vibration signals at different phases (particularly using the vibration amplitude at the excitation frequency and its harmonics), the system extracts both mass flow and pressure information from the same sensor signals, eliminating the need for separate pressure sensors and reducing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If additional sensors and modified exciter arrangements are used to achieve high precision mass flow and pressure measurements, then measurement precision is improved, but calibration efforts increase

Engineering Contradiction:
Improvepressure measurement precisionVSAvoidcalibration effort
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The system performs self-calibration by utilizing the existing vibration sensor signals for both mass flow and pressure measurements. The evaluation circuit processes the vibration signals to simultaneously determine both parameters, and the system can automatically compensate for pressure effects on mass flow measurements using the same sensor data, reducing the need for external calibration equipment and procedures.

Inventive Principle:
Principle #25Self-service

3Reliability

If vibration sensors are placed close to the exciter, then signal strength is improved, but sensitivity to pressure fluctuations increases

Engineering Contradiction:
Improvesignal detection reliabilityVSAvoidpressure fluctuation sensitivity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the evaluation parameters of the vibration signals by analyzing them at different phases and frequencies. Instead of simply measuring vibration amplitude near the exciter, the system evaluates the vibration signals at the excitation frequency and its harmonics, and uses phase information to distinguish between mass flow effects and pressure effects. This parameter transformation allows the system to maintain signal strength while reducing sensitivity to pressure fluctuations.

Inventive Principle:
Principle #35Parameter changes

4Volume of moving object

If a compact design with integrated measuring transducer is used, then device size is reduced, but measurement precision may deteriorate

Engineering Contradiction:
Improvemeasuring device volumeVSAvoidmass flow measurement precision
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The patent merges the mass flow measurement and pressure measurement functions into a single integrated transducer unit. The vibration sensors that were originally designed for mass flow measurement are now used for both purposes, and the evaluation circuit integrates both measurement functions in one processing unit. This merging maintains compact device size while achieving high precision for both measurements through sophisticated signal evaluation.

Inventive Principle:
Principle #5Merging (Combining)

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

The system provides precise measurement of mass flow and pressure with reduced sensitivity to pressure fluctuations, utilizing existing vibration sensors and evaluation circuits, thereby simplifying the setup and improving measurement accuracy.

Implementation Method 1

an electrodynamic vibration exciter (41) acting on the measuring tube (10) for causing the at least one measuring tube (10) to vibrate

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

electrodynamic, first vibration sensor (51), which delivers a first primary signal (s1) of the measuring transducer representing vibrations of the measuring tube (10)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

which induce reaction forces, for example Coriolis forces, in the flowing medium by means of a vibration-type measuring transducer

Methodology Applied
Scientific EffectCoriolis force: Coriolis Force

Data Source

PatentEP2406592B1Measuring system with vibrational type transducer
Publication Date: 2021.06.23 ENDRESS HAUSER FLOWTEC AG
  • EP2406592B1 patent drawingFigure 1a~1b
  • EP2406592B1 patent drawingFigure 2
  • EP2406592B1 patent drawingFigure 3

AI summary

Disclosed is a measuring system that is particularly designed as a compact measuring instrument and/or a Coriolis mass flow meter and comprises a transducer, through which a medium flows at least temporarily during operation and which generates primary signals influenced by at least one measured variable characterizing the flowing medium, and an evaluation circuit which is electrically coupled to the transducer and processes primary signals supplied by the transducer into measured values. The transducer includes at least one measuring tube (10) for conducting medium to be measured, said measuring tube (10) at least temporarily vibrating during operation, an exciter arrangement (40) for making the at least one measuring tube (10) vibrate, said exciter arrangement (40) including at least one vibrator that acts on the measuring tube, and a sensor array (50) which senses vibrations of the measuring tube (10). The sensor array generates a first primary transducer signal representing vibrations of the measuring tube (10) by means of a first vibration sensor (51) that is disposed on the measuring tube (10) at a distance from the at least one vibrator, a second primary transducer signal representing vibrations of the measuring tube (10) by means of a second vibration sensor (52) that is disposed on the measuring tube (10) at a distance from the first vibration sensor (51), and a third primary transducer signal representing vibrations of the measuring tube (10) by means of a third vibration sensor (53) that is disposed on the measuring tube (10) at a distance from the first vibration sensor (51) and from the second vibration sensor (52). Using the first primary signal (s1), the second primary signal (s2), and the third primary signal (s3), the evaluation circuit of the measuring system of the invention at least temporarily generates a measured mass flow value (Xm) currently representing a mass flow rate (m) of the medium flowing through the transducer.