Furnace Control for Aluminum Sheet Annealing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Continuous heat treating and annealing processes for aluminum alloy sheets face challenges in maintaining consistent peak metal temperature during variations in line speed, leading to non-conforming product characteristics and reduced mechanical properties.

Innovation Solution

A method that adjusts fan speeds and furnace air temperature in a continuous convection floating furnace to maintain the peak metal temperature within +/- 5°C of the target temperature by measuring and controlling line speed, fan speeds, and furnace air temperature, using equations to compensate for changes in line speed and ensure consistent heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If line speed is varied to accommodate production requirements, then productivity is improved, but peak metal temperature consistency deteriorates

Engineering Contradiction:

Improveline speedVSAvoidpeak metal temperature consistency

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by making the fan speeds and furnace air temperature adjustable in response to line speed variations. The system continuously measures actual line speed and dynamically modifies heating parameters (fan speeds in zones, air temperature) to compensate for speed changes, ensuring consistent peak metal temperature despite variable production rates

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by continuously measuring the actual line speed of the aluminum alloy sheet and using this information to adjust fan speeds and furnace air temperature. The control system compares actual speed with set point speed and modifies heating parameters accordingly, creating a closed-loop control system that maintains temperature consistency

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If fan speeds are increased to maintain temperature during acceleration, then energy consumption increases, but temperature control precision is improved

Engineering Contradiction:

Improvetemperature control precisionVSAvoidfan energy consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by adjusting fan speeds and furnace air temperature based on the direction and magnitude of line speed changes. The system increases fan speeds during acceleration to maintain temperature, and reduces fan speeds during deceleration, optimizing energy consumption while maintaining temperature control precision through dynamic parameter modification

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If furnace air temperature is increased to compensate for deceleration, then risk of overheating increases, but temperature consistency is improved

Engineering Contradiction:

Improvetemperature consistencyVSAvoidoverheating risk

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the furnace air temperature adjustable in response to line speed variations. The system continuously measures actual line speed and dynamically modifies heating parameters (fan speeds in zones, air temperature) to compensate for speed changes, ensuring consistent peak metal temperature despite variable production rates

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies local quality by implementing zone-specific fan speed control within the furnace. Different zones (heating zone, peak metal temperature zone, cooling zone) have independently controllable fans that can be adjusted according to local requirements and actual line speed conditions, allowing precise temperature management in each section

Inventive Principle:

Principle #3Local quality

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 effectively maintains peak metal temperature control during decelerations or accelerations, ensuring consistent product properties and reducing scrap by maintaining temperature within +/- 2°C of the target, even during extended line speed reductions.

Implementation Method 1

independently controllable fans blowing above and below the aluminum alloy sheet along the path for guiding the aluminum alloy sheet along the path

Methodology Applied

Scientific EffectAir cushion / Floating: Air Lubrication

Implementation Method 2

contiguous heat treatment zones have independently controllable convection heaters along the path for heating the aluminum alloy sheet

Methodology Applied

Scientific EffectConvection heating: Convection

Implementation Method 3

arranged to heat the moving aluminum sheet to a set peak metal temperature (T PMT)

Methodology Applied

Scientific EffectHeat transfer: Convection

Data Source

PatentEP3959346B1Line speed dependent control of a furnace for heat treating aluminum alloy sheet

Publication Date: 2023.04.12 COMMONWEALTH ROLLED PROD INC

Figure 1~2
Figure 3~5
Figure 6

AI summary

A method for controlling continuous heat treating and annealing of heat-treatable and non-heat-treatable aluminum alloy sheet at final thickness continuously moving in a floating state horizontally through a continuous convection floating furnace arranged to heat the moving aluminum sheet to a set peak metal temperature. The controlling including controlling fan speeds and furnace air temperature to accommodate variations in line speed of the aluminum alloy sheet continuously moving in the floating state horizontally through the continuous convection floating furnace