Furnace Control for Real-Time End-of-Melt Detection

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Solution Overview

Problem

The variability in scrap metal composition and furnace conditions in secondary metal recycling processes leads to inconsistent operational efficiency and productivity in melting furnaces, with existing methods lacking a consistent and accurate method for determining the end of melt, resulting in potential under-heating or over-heating of metals, which affects recovery and energy consumption.

Innovation Solution

A controller system that utilizes real-time and historical data to model performance and adjust furnace operations through a regression analysis, allowing for real-time corrections to operational parameters, such as burner firing rate and furnace rotation speed, to optimize melting processes and reduce aluminum oxidation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If operators manually handle multiple melt furnaces based on conventional methods, then operational flexibility is maintained, but process variability increases and productivity decreases

Engineering Contradiction:
Improvemelting productivityVSAvoidprocess consistency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system implements feedback control by continuously monitoring furnace temperature, charge material composition, and operational parameters, then automatically adjusting burner firing rates and other controls to maintain optimal melting conditions. This closed-loop feedback mechanism eliminates manual variability and ensures consistent productivity across multiple furnaces.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The furnace control system operates autonomously by self-adjusting operational parameters based on real-time sensor data and pre-programmed optimization algorithms. The system automatically determines when charge material is ready for tapping without operator intervention, enabling furnaces to self-optimize their melting processes and eliminate human-induced variability.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If conventional temperature monitoring methods are used to determine end of melt, then operational simplicity is maintained, but measurement precision decreases leading to under-heating or over-heating

Engineering Contradiction:
Improveend of melt detection accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system replaces conventional mechanical temperature monitoring and manual assessment methods with automated electronic sensors, data acquisition systems, and computer-based control algorithms. This substitution of mechanical/manual systems with electronic automation enables precise real-time measurement of temperature and material state, accurately determining end of melt conditions without human error.

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

Solution Approach 2:

The control system integrates multiple functions including temperature monitoring, composition analysis, predictive modeling, and automatic control adjustment into a single unified platform. This multi-functional system handles diverse measurement tasks (temperature, composition, timing) through integrated sensors and algorithms, providing comprehensive end-of-melt detection without requiring separate complex specialized devices.

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

3Productivity

If high burner firing rates are used to accelerate melting, then productivity increases, but energy consumption increases and aluminum oxidation worsens

Engineering Contradiction:
Improvemelting rateVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The system dynamically adjusts burner firing rates based on real-time feedback from temperature sensors and predictive models. Rather than maintaining constant high firing rates, the system optimizes power input at each stage of the melting process, applying high power only when needed to accelerate melting, then reducing power as the material approaches completion. This dynamic control maintains high productivity while minimizing unnecessary energy consumption and aluminum oxidation.

Inventive Principle:
Principle #15Dynamics

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 system improves the consistency and efficiency of metal melting by accurately determining the end of melt, reducing energy consumption, and enhancing productivity while minimizing aluminum oxidation and carbon emissions.

Implementation Method 1

determining x-variables for the one or more cycles of operation of the furnace and feeding the x-variables into a regression model to determine a relationship between at least one of the x-variables with at least one y-variable

Methodology Applied
Scientific EffectRegression analysis:

Implementation Method 2

a furnace to melt a material that comprises metal

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

melting of metal scrap from varied sources and upstream processes

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3943854A1Furnace controller and method of operating a furnace
Publication Date: 2022.01.26 AIR PROD & CHEM INC
  • EP3943854A1 patent drawingFigure 1
  • EP3943854A1 patent drawingFigure 2
  • EP3943854A1 patent drawingFigure 3

AI summary

A control scheme for a furnace can use real-time and historical data to model performance and determine relationships between different data and performance parameters for use in correcting suboptimal performance of the furnace in real-time. Operational parameters can be logged throughout the cycle for all cycles for a period of time in order to establish a baseline. This data can then be used to calculate the performance of the process. A regression analysis can be carried out in order to determine which parameters affect different aspects of performance. These relationships can then be used to predict performance during a single cycle in real-time and provide closed or open loop feedback to control furnace operation to result in enhanced performance.