Furnace Flame Rod Current Monitoring for Remaining Life Prediction

Solution Overview

Problem

Flame rods in furnaces degrade over time, affecting their ability to detect flames accurately, and existing systems lack effective methods to monitor and predict this degradation.

Innovation Solution

A system and method that continuously or intermittently monitors the electrical current of the flame rod, using a current degradation data model to predict the remaining life of the flame rod based on average current and burn time, and provides alerts or notifications when degradation exceeds a threshold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flame rod is used to detect flame presence, then flame detection function is achieved, but flame rod degrades over time affecting detection accuracy

Engineering Contradiction:

Improveflame detection accuracyVSAvoidflame rod service life

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system performs preliminary monitoring of flame rod current at regular intervals during furnace operation to detect degradation trends before the flame rod fails completely. By continuously tracking current changes and comparing against baseline values, the system predicts remaining useful life and schedules maintenance proactively, preventing detection failures rather than reacting to them after occurrence.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback loop by continuously measuring flame rod current, comparing it to historical baseline data, and using the deviation to update degradation predictions. This closed-loop feedback mechanism allows the system to adapt to changing conditions and accurately track flame rod health status over time, maintaining reliable detection throughout the service life.

Inventive Principle:

Principle #23Feedback

2Loss of information

If existing monitoring systems are used, then basic operation monitoring is achieved, but no effective prediction of flame rod degradation is provided

Engineering Contradiction:

Improvedegradation prediction capabilityVSAvoidmaintenance timing accuracy

Core Design Contradiction:

Loss of informationVSReliability

Solution Approach 1:

The system performs preliminary monitoring of flame rod current at regular intervals during furnace operation to detect degradation trends before the flame rod fails completely. By continuously tracking current changes and comparing against baseline values, the system predicts remaining useful life and schedules maintenance proactively, preventing detection failures rather than reacting to them after occurrence.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback loop by continuously measuring flame rod current, comparing it to historical baseline data, and using the deviation to update degradation predictions. This closed-loop feedback mechanism allows the system to adapt to changing conditions and accurately track flame rod health status over time, maintaining reliable detection throughout the service life.

Inventive Principle:

Principle #23Feedback

3Reliability

If flame rod degradation is not monitored, then system complexity is reduced, but malfunction risk increases

Engineering Contradiction:

Improveflame detection reliabilityVSAvoidmonitoring system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The monitoring system leverages the existing flame rod electrical connection and controller infrastructure to perform multiple functions: normal flame detection, current measurement for degradation analysis, and predictive maintenance scheduling. By making the existing controller multi-functional, the system avoids adding dedicated monitoring hardware, thereby limiting complexity increase while achieving reliable degradation monitoring.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses the flame rod's own electrical current characteristics as the monitoring signal, eliminating the need for separate sensors or diagnostic components. The existing excitation voltage and current measurement circuitry serve dual purposes: operating the flame rod and monitoring its health, allowing the flame rod system to self-diagnose its condition without external monitoring equipment.

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

Enables proactive maintenance by predicting the remaining life of the flame rod, ensuring reliable flame detection and reducing the risk of malfunction.

Implementation Method 1

Furnaces utilize a flame rod to detect the presence of a flame within the furnace

Methodology Applied

Scientific EffectIonization: Ionisation

Data Source

PatentUS12584629B2System and method to detect flame rod/sensor malfunction

Publication Date: 2026.03.24 FIREYE LLC

AI summary

A method of monitoring a flame rod of a furnace including: detecting an average current of the flame rod during a burn cycle of the furnace; determining a burn time of the burn cycle of the furnace; and determining a remaining life of the flame rod based on at least the average current and the burn time.