Magnetic Chip Detector Sizing by Joule Heating in Engine Fluid

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing chip detection systems in aircraft engines struggle to differentiate between harmless 'fuzz' and potentially problematic metal chips, leading to nuisance alarms and inaccurate health assessments.

Innovation Solution

A method and system that uses Joule heating to burn detected chips, measuring the energy consumed during this process to determine their size, thereby distinguishing between harmless debris and potentially problematic chips.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional chip detection systems are used to detect all metal particles, then sensitivity to detect chips is improved, but false alarms increase due to inability to differentiate between harmless fuzz and problematic chips

Engineering Contradiction:
Improvechip detection accuracyVSAvoidalarm reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies parameter changes by measuring the energy consumption during chip burning process. Different chip sizes consume different amounts of energy, allowing the system to distinguish between harmless fuzz (low energy) and problematic chips (high energy). This transforms the detection parameter from simple presence/absence to quantitative energy measurement, resolving the contradiction between detection sensitivity and alarm reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the traditional mechanical/electrical continuity-based detection system with a thermal-energy based system. Instead of relying on electrical continuity alone, the system uses Joule heating to burn chips and measures the energy consumed. This substitution enables differentiation between particle types based on their thermal response, improving both detection accuracy and alarm reliability.

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

2Difficulty of detecting and measuring

If chip detection sensitivity is increased to detect smaller particles, then detection capability is improved, but nuisance alarms from harmless debris increase

Engineering Contradiction:
Improvechip detection capabilityVSAvoidnuisance alarms
Core Design Contradiction:
Difficulty of detecting and measuringVSObject-generated harmful factors

Solution Approach 1:

The system changes the detection parameter from binary electrical continuity to continuous energy measurement. By measuring the exact energy consumed during burning, the system can detect smaller particles while filtering out harmless debris through energy threshold analysis. This parameter transformation enables sensitive detection without proportionally increasing nuisance alarms.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces energy measurement as an intermediary between chip detection and alarm generation. The energy consumption data serves as a mediating parameter that allows the system to evaluate detected particles before triggering alarms. This intermediary layer enables discrimination between significant chips and insignificant debris, reducing nuisance alarms while maintaining detection capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If energy measurement is used to determine chip size, then measurement precision is improved, but system complexity increases

Engineering Contradiction:
Improvechip size measurement accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by using the same electrical circuit and power source for both chip detection and energy measurement functions. The existing electrical continuity detection infrastructure is extended to also measure energy consumption during burning. This multi-functionality approach enables precise chip size measurement without proportionally increasing system complexity, as the same hardware serves dual purposes.

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

Solution Approach 2:

The system uses the chip itself as the heating element during the burning process. The electrical current passes through the chip, utilizing its own electrical resistance to generate heat for burning. This self-service approach eliminates the need for external heating mechanisms, simplifying the system while enabling energy measurement for chip size determination.

Inventive Principle:
Principle #25Self-service

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

Accurately sizes chips to provide reliable health assessments, reducing nuisance alarms and improving the accuracy of maintenance scheduling.

Implementation Method 1

burning the chip by Joule heating by continuously driving electric current through the chip

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4137805B1Method and system for sizing a chip in engine fluid
Publication Date: 2025.09.24 PRATT & WHITNEY CANADA CORP
  • EP4137805B1 patent drawingFigure 1
  • EP4137805B1 patent drawingFigure 2
  • EP4137805B1 patent drawingFigure 3

AI summary

Methods and systems of estimating a size of a chip (37) in engine fluid (26) of an engine (10) are provided. One method comprises detecting the chip (37) at a magnetic chip detector (28) immersed in the engine fluid (26), burning the chip (37) by Joule heating using a single delivery of electric current (I) through the chip (37) via the first and second terminals (36A, 36B) of the magnetic chip detector (28), determining an amount of energy consumed to burn the chip (37), and estimating the size of the chip (37) based on the amount of energy consumed to burn the chip (37).