Flow Meter Impeller Titanium Modulator Segment Corrosion

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Solution Overview

Problem

Existing flow meters face challenges in achieving high measurement accuracy over time, sensitivity to chemically aggressive fluids, and cost-effectiveness due to corrosion issues with conductive materials and balancing problems caused by their weight differences.

Innovation Solution

The use of titanium for the modulator segment, which offers high corrosion resistance, conductivity, and mechanical strength, allowing for a lightweight and cost-effective design that maintains measurement accuracy and balances the impeller without significant weight imbalances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a highly conductive metal modulator segment is used, then measurement sensitivity is improved, but corrosion resistance deteriorates

Engineering Contradiction:
Improvemeasurement sensitivityVSAvoidcorrosion resistance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies a composite material structure consisting of a plastic impeller body combined with a metal modulator segment. The plastic provides corrosion resistance while the metal segment provides electrical conductivity for measurement. This composite approach resolves the contradiction by combining materials with complementary properties - the plastic matrix protects against corrosion while the embedded metal foil (5-20 μm thick) maintains the necessary electrical conductivity for generating eddy currents in the sensing coil.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If a highly conductive metal modulator segment is used, then measurement sensitivity is improved, but weight increases causing imbalance

Engineering Contradiction:
Improvemeasurement sensitivityVSAvoidimpeller balance
Core Design Contradiction:
Measurement precisionVSWeight of moving object

Solution Approach 1:

The patent uses a thin metal foil layer (5-20 μm thickness) as the modulator segment instead of a bulky metal component. This thin film approach provides sufficient electrical conductivity for measurement while minimizing the added weight. The metal foil is embedded within the plastic impeller structure, which helps distribute and balance the weight distribution, reducing rotational imbalance while maintaining the necessary conductivity for generating eddy currents.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If the modulator segment is encapsulated to prevent corrosion, then corrosion resistance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the modulator segment manufacturing with the impeller manufacturing process. The metal foil is positioned on the impeller and then the entire assembly is injection-molded as a single integrated component. This combining of steps eliminates the need for separate encapsulation processes, reducing manufacturing complexity while providing inherent corrosion protection through the plastic material that forms part of the impeller structure itself.

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 titanium modulator segment provides enhanced corrosion resistance, improved measurement sensitivity, and balanced weight distribution, enabling precise and long-lasting flow meter operation while reducing production costs.

Implementation Method 1

The sensing coil is part of an electrical oscillating circuit, whose oscillation is periodically damped by the modulator segment mounted on the impeller. This occurs when the modulator segment, made of a highly electrically conductive material, passes through the magnetic field of the sensing coil, inducing eddy currents in the modulator segment.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

This occurs when the modulator segment, made of a highly electrically conductive material, passes through the magnetic field of the sensing coil, inducing eddy currents in the modulator segment.

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Data Source

PatentEP3477265B2Flow meter
Publication Date: 2024.11.27 ENGELMANN SENSOR
  • EP3477265B2 patent drawingFigure 1a~1b
  • EP3477265B2 patent drawingFigure 2a~2b
  • EP3477265B2 patent drawingFigure 3

AI summary

A flow meter for measuring the volumetric flow rate of a fluid such as heating water has a measuring chamber (3) through which the fluid flows, an impeller (4) rotatably mounted in the measuring chamber (3), a sensor device with an electrical resonant circuit containing at least one scanning coil, and at least one modulator segment arranged on the impeller (4) which induces damping of the resonant circuit depending on the angle of rotation. The modulator segment is a piece of flat, bare sheet metal made of pure titanium.