Electromagnetic Flowmeter Coil Segmentation for Magnetic Field Homogeneity

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Solution Overview

Problem

Existing electromagnetic flowmeters for large pipes face challenges in constructing and maintaining large coils that generate a uniform magnetic field, leading to high costs and potential measurement inaccuracies due to improper installation or degradation.

Innovation Solution

The use of multiple pairs of coils, where primary pairs generate the main magnetic field and secondary pairs can be independently excited to enhance magnetic field homogeneity and strength, allowing for even distribution across the pipe cross-section and compensating for field degradation or installation issues without additional elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If large diamond-shaped or rhombus-shaped coils are used to cover half of the circumference of a measuring section, then the magnetic field is distributed across the cross section of the flowmeter, but the coils become difficult to construct and require substantial costs

Engineering Contradiction:
Improvemagnetic field distribution uniformityVSAvoidcoil construction difficulty
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent divides the single large coil into multiple smaller coils (first coil, second coil, third coil, fourth coil) arranged around the measuring section. Each coil covers a portion of the circumference, and together they generate the magnetic field across the entire cross-section. This segmentation reduces the complexity of constructing each individual coil while maintaining the overall magnetic field distribution uniformity.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If large diamond-shaped or rhombus-shaped coils are used to cover half of the circumference of a measuring section, then the magnetic field is distributed across the cross section of the flowmeter, but the installation becomes complex and requires special care

Engineering Contradiction:
Improvemagnetic field distribution uniformityVSAvoidcoil installation complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

By segmenting the large coil into multiple smaller coils positioned at different locations around the measuring section, the installation process becomes simpler. Each smaller coil can be installed and positioned more easily compared to a single large coil, reducing the special care and precision required during installation while still achieving uniform magnetic field distribution.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If single plane electrode arrangement is used in electromagnetic flowmeter, then the structure is simple, but the magnetic field generation for large diameter pipes becomes challenging

Engineering Contradiction:
Improveelectrode arrangement simplicityVSAvoidmagnetic field generation capability
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the magnetic field generation task into multiple smaller coils distributed around the measuring section. This allows the system to effectively generate magnetic fields for large diameter pipes by combining the contributions of multiple smaller coils, each contributing to the overall magnetic field distribution across the pipe cross-section.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-plane electrode arrangement to a multi-dimensional coil configuration where coils are arranged around the circumference of the measuring section. This dimensional change enables effective magnetic field generation for large diameter pipes by utilizing the circumferential arrangement of multiple coils.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 configuration reduces construction costs, improves measurement accuracy by ensuring even magnetic field distribution, and minimizes the need for frequent calibration and maintenance by dynamically adjusting the magnetic fields in response to operational conditions.

Implementation Method 1

A magnetic field is generated perpendicular to the flow direction, and accordingly due to the interaction between the magnetic field and the conductive fluid flowing, a voltage perpendicular to the magnetic field and to the flow direction is generated

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the secondary pairs of coils are capable of being excited independently in relation the one or more primary pairs of coils. Upon the detection of a predefined event, the transmitter is configured to excite the secondary pairs of coils. Upon excitation, the one or more secondary pairs of coils generate at least one secondary magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

due to the interaction between the magnetic field and the conductive fluid flowing, a voltage perpendicular to the magnetic field and to the flow direction is generated and which is then measured by means of electrodes

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4275018B1An electromagnetic flowmeter with primary and secondary pairs of coils
Publication Date: 2024.09.11 SIEMENS AG
  • EP4275018B1 patent drawingFigure 1
  • EP4275018B1 patent drawingFigure 2
  • EP4275018B1 patent drawingFigure 3

AI summary

The current disclosure describes an electromagnetic flowmeter comprising one or more primary pairs of coils and one or more secondary pairs of coils, and a transmitter. The one or more primary pairs of coils generate one or more magnetic fields within the measuring section, for measuring the volumetric flow of fluid. The secondary pairs of coils are capable of being excited independently in relation the primary pairs of coils. Upon detection of a predefined event, the transmitter is configured to excite the secondary pairs of coils, to generate at least one secondary magnetic field. The generated least one secondary magnetic field interacts with at least one magnetic field from the one or more magnetic fields generated by the primary pairs of coils, for improving at least one of a magnetic field homogeneity or magnetic field strength in a measuring of the flowmeter.