Non-Contact Apparent Density Measurement for Mixed Powder Production

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Solution Overview

Problem

Existing methods for measuring the apparent density of metal powders in powder metallurgy are limited by the need for offline sampling and are not precise enough to maintain consistent density in production lines, especially due to environmental factors like temperature and humidity, which can affect the quality of finished products.

Innovation Solution

A non-contact method using an alternating magnetic flux to measure the apparent density of metal powders by applying a magnetic field with an exciting coil and detecting the flux with a search coil, allowing for continuous online monitoring without disrupting the production process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sampling measurement is performed according to JIS Z 2504:2000, then measurement precision is improved, but productivity deteriorates due to stopping the mixing or compacting operation

Engineering Contradiction:
Improveapparent density measurement precisionVSAvoidproduction continuity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical sampling system with an electromagnetic measurement system. Instead of physically removing powder samples and stopping production, the invention uses electromagnetic fields to measure apparent density continuously through the hopper and feeder walls, enabling non-contact measurement without interrupting the mixing or compacting operations

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces electromagnetic fields as an intermediary measurement medium. The measurement coils generate electromagnetic fields that penetrate the hopper and feeder structures to detect powder density characteristics without direct contact with the powder, allowing continuous monitoring while maintaining production flow

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If environmental factors are not controlled, then ease of operation is improved, but manufacturing precision deteriorates due to variations in powder density

Engineering Contradiction:
Improveoperation simplicityVSAvoidpowder compact density consistency
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements a feedback control system where electromagnetic measurement coils continuously monitor apparent density in real-time during mixing and compacting operations. The measured density values are fed back to control systems that automatically adjust process parameters to maintain consistent powder compact quality, compensating for environmental variations without adding operational complexity

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary measurement and adjustment of powder density before compaction. By measuring apparent density in advance during the mixing and feeding stages, the system can predict and compensate for density variations that would otherwise affect final compact quality, ensuring consistent manufacturing results

Inventive Principle:
Principle #10Preliminary action

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 method enables high-precision, continuous measurement of apparent density, ensuring consistent powder compacts and improving the quality of finished products by adjusting mixing and compaction conditions in real-time.

Implementation Method 1

applying an alternating magnetic flux to the mixed powder using an exciting coil which is disposed outside the mixer

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

detecting an alternating magnetic flux passed through the mixed powder using a search coil disposed outside the mixer

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2772754B1Production method and production device for mixed powder
Publication Date: 2019.11.13 JFE STEEL CORP
  • EP2772754B1 patent drawingFigure 1~2
  • EP2772754B1 patent drawingFigure 3~5
  • EP2772754B1 patent drawingFigure 6~7

AI summary

A method for measuring an apparent density of a metal powder includes holding a metal powder in a vessel, applying an alternating magnetic flux to the metal powder using an exciting coil disposed outside the vessel, detecting the alternating magnetic flux passed through the metal powder using a search coil disposed outside the vessel, and determining an apparent density of the metal powder from an amplitude of the detected alternating magnetic flux using a calibration curve representing a correlation between the apparent density of the metal powder and the amplitude of an alternating magnetic flux prepared in advance. The method enables to measure the apparent density of a metal powder with a high precision in an on-line and non-contact manner without stopping a process of producing a mixed powder or a process of producing a powder compact.