Coriolis Flow Meter Connecting Device Stiffening

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Coriolis mass flowmeters with two measuring tubes face significant interference from orthogonal vibrations, which distort the measurement signal due to insufficient frequency separation between excitation and orthogonal oscillations.

Innovation Solution

The connecting device is enhanced with a stiffening plate and fin arrangement, where the stiffening fin is perpendicular to the stiffening plate, increasing flexural rigidity in the common plane while reducing torsional rigidity, thereby separating excitation and orthogonal vibrations effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the measuring tubes are excited to vibrate in their common plane for mass flow measurement, then the measurement function is achieved, but orthogonal vibrations interfere with the measurement signal due to insufficient frequency separation

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidorthogonal vibration interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the structural parameters of the connecting device by adding a stiffening fin perpendicular to the stiffening plate, which selectively modifies the flexural rigidity in the common plane while maintaining lower torsional rigidity for orthogonal vibrations. This parameter change creates greater frequency separation between excitation and orthogonal vibrations, reducing measurement interference

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The stiffening fin is arranged asymmetrically perpendicular to the stiffening plate, creating different rigidity characteristics for different vibration directions. This asymmetry ensures that flexural vibrations in the common plane are restrained more than torsional vibrations perpendicular to it, achieving better frequency separation and reducing harmful orthogonal vibration interference

Inventive Principle:
Principle #4Asymmetry

2Reliability

If the connecting device is made stiffer to reduce vibration interference, then frequency separation improves, but the device complexity increases

Engineering Contradiction:
Improvevibration isolationVSAvoidconnecting device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of making the entire connecting device uniformly stiffer, the patent applies local stiffening only where needed by adding a stiffening fin perpendicular to the stiffening plate. This localized modification selectively increases flexural rigidity in the common plane while keeping torsional rigidity相对较低, achieving vibration isolation without excessive complexity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The connecting device is segmented into functional components: a stiffening plate for basic structural support and a stiffening fin for selective rigidity enhancement. This segmentation allows each component to perform its specific function efficiently, achieving reliable vibration isolation with minimal added complexity

Inventive Principle:
Principle #1Segmentation

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

This design significantly reduces the influence of orthogonal vibrations on the measurement signal, enhancing measurement accuracy by achieving better frequency separation and minimizing signal disturbance.

Implementation Method 1

a mass flow meter which works according to the Coriolis principle

Methodology Applied
Scientific EffectCoriolis force: Coriolis Force

Data Source

PatentEP1881303B1Coriolis Mass flow measuring device
Publication Date: 2018.11.28 KROHNE AG
  • EP1881303B1 patent drawingFigure 1~2
  • EP1881303B1 patent drawingFigure 3~4
  • EP1881303B1 patent drawingFigure 5

AI summary

The invention relates to a mass flow meter operating according to the Coriolis principle, comprising two measuring tubes (1) running in a common plane at least in one section, and a connecting device (2) by means of which the two measuring tubes (1) are connected to each other in the section where they run in the common plane. According to the invention, the connecting device (2) has a stiffening plate (3) attached to both measuring tubes (1) and arranged parallel to the common plane of the measuring tubes, and a stiffening fin (5) is provided on the stiffening plate (3). In this way, the bending stiffness of the connecting device (2) for bends in the common plane of the measuring tubes (1), in which the excitation vibrations of the measuring tubes (1) generally also occur, can be made greater than the torsional stiffness of the connecting device (2) for torsional vibrations.As a result, the measurement accuracy of the Coriolis mass flow meter is improved.