Coriolis Mass Flow Meter Node Stiffening for Spurious Vibration Control

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Solution Overview

Problem

Existing Coriolis mass flowmeters face challenges in effectively separating unwanted parasitic vibrations, which affect measurement accuracy.

Innovation Solution

The integration of stiffening elements into node elements, designed to increase the stiffness of the measuring tube with respect to oscillations orthogonal to the excitation and Coriolis modes, allowing for the effective suppression and filtration of these vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If node plates or node rings are arranged on the inlet and outlet sides of the measuring tube to define the vibration range, then the vibration nodes are fixed at the ends, but spurious vibrations deviating from the Coriolis mode cannot be effectively suppressed

Engineering Contradiction:
Improveflow rate measurement accuracyVSAvoidspurious vibrations
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by integrating stiffening elements directly into the node elements at specific locations where spurious vibrations occur. The stiffening elements are positioned locally at the node elements (inlet and outlet sides) to provide targeted suppression of parasitic vibrations without affecting the overall vibration mode definition. This localized reinforcement increases the stiffness of the measuring tube at critical points, effectively suppressing spurious vibrations while maintaining the necessary vibration characteristics for flow measurement.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by combining the node element structure with integrated stiffening elements. The node element serves dual functionality: defining vibration nodes and providing structural reinforcement through the integrated stiffening elements. This composite structure merges the vibrational control function with the mechanical reinforcement function, creating a unified component that addresses both measurement requirements and spurious vibration suppression.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If stiffening elements are added to suppress spurious vibrations, then measurement accuracy improves, but device complexity increases

Engineering Contradiction:
Improvevibration mode separationVSAvoidnumber of components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies merging by integrating the stiffening elements directly into the node elements, creating a unified component structure. Instead of adding separate stiffening elements as independent components, the design combines the vibrational node definition function with the structural reinforcement function in a single integrated element. This reduces the total number of discrete parts while achieving the dual objectives of defining vibration nodes and suppressing spurious vibrations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements multi-functionality by designing the node elements to perform multiple functions simultaneously: defining vibration nodes, providing structural support, and suppressing spurious vibrations through the integrated stiffening elements. This universal design approach allows a single component to fulfill multiple requirements, reducing overall device complexity while maintaining measurement precision.

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

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

Enhances measurement accuracy by distinguishing and filtering out disruptive vibrations, thereby improving the overall performance of the Coriolis mass flowmeter.

Implementation Method 1

a vibration generator (8) that excites the measuring tube (6) to vibrate during operation

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

The flowing medium causes the tube to form a Coriolis mode, which typically corresponds to the first harmonic of the excitation mode

Methodology Applied
Scientific EffectCoriolis force: Coriolis Force

Implementation Method 3

the stiffening element increases the stiffness of the measuring tube with respect to oscillations orthogonal to the excitation mode and to the Coriolis mode, so that during operation the oscillation frequency of the oscillation orthogonal to the excitation mode and to the Coriolis mode is higher than the oscillation frequency of the excitation mode

Methodology Applied
Scientific EffectStiffness:

Data Source

PatentEP3819601B1Coriolis mass flow meter and node element
Publication Date: 2025.08.20 KROHNE AG
  • EP3819601B1 patent drawingFigure 1~2
  • EP3819601B1 patent drawingFigure 3~5
  • EP3819601B1 patent drawingFigure 6

AI summary

A Coriolis mass flow meter (1) with at least one measuring tube (6), with at least one vibration generator (8) and at least two vibration sensors (9) and with at least two node elements (2) is described and illustrated, wherein the at least one vibration generator (8) excites the measuring tube (6) to a vibration during operation, wherein the at least two node elements define the vibration range and wherein at least one node element (2) has at least one stiffening element (3).The problem of specifying a Coriolis mass flow meter that ensures a particularly effective separation of unwanted disturbance vibrations of the measuring tube is solved by the fact that the at least one node element (2) is designed and arranged in such a way that the stiffening element (3) increases the stiffness of the measuring tube (6) with respect to vibrations orthogonal to the excitation mode and the Coriolis mode, so that in operation the vibration frequency of the vibration orthogonal to the excitation mode and the Coriolis mode is higher than the vibration frequency of the excitation mode, preferably higher than the frequency of the Coriolis mode.