Metal Strip Coiling Temperature Control with Predictive Furnace Adjustment

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Solution Overview

Problem

Existing methods for coiling metal strips in a warm state lack sufficient temperature control accuracy, with deviations of ±10°C due to sluggish reaction times in furnaces, which can impact material properties.

Innovation Solution

A predictive model is used to calculate future outlet speed and heat losses, allowing for automatic control of furnace parameters to maintain the metal strip at a specified temperature within ±5°C, employing techniques such as hot air, radiation, or electromagnetic heating to ensure precise temperature control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pre-aging furnace is controlled based on measured strip temperature, then the strip temperature can be maintained relatively stably, but the temperature control accuracy is insufficient with deviations of ±10°C

Engineering Contradiction:
Improvetemperature stabilityVSAvoidtemperature control accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The predictive model calculates the required furnace temperature in advance based on the measured strip temperature, outlet speed, and heat loss characteristics. This preliminary calculation allows the furnace to be adjusted proactively before temperature deviations occur, rather than reactively after measurement, thereby achieving both stability and precision with ±2°C or better accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements a closed-loop feedback mechanism where the measured strip temperature is continuously fed back to the predictive model. The model uses this feedback along with outlet speed data to dynamically adjust the furnace temperature setpoint, ensuring accurate temperature control despite variations in operating conditions.

Inventive Principle:
Principle #23Feedback

2Productivity

If the outlet speed of the metal strip changes, then the productivity and response to coil changes are improved, but the dwell time in the furnace changes causing temperature deviations

Engineering Contradiction:
Improveoutlet speedVSAvoidtemperature control accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The predictive model incorporates outlet speed as a key input parameter and calculates the required furnace temperature adjustment in advance. When outlet speed changes occur, the model proactively adjusts the furnace temperature setpoint to compensate for the resulting dwell time changes, maintaining temperature accuracy despite productivity variations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically changes the furnace temperature parameter based on outlet speed variations. The predictive model establishes a relationship between outlet speed and required furnace temperature, automatically adjusting the temperature parameter to maintain constant strip temperature at the coiler regardless of speed changes.

Inventive Principle:
Principle #35Parameter changes

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 method achieves precise temperature control, maintaining the metal strip at the desired coiling temperature with a deviation of less than ±2°C, optimizing material properties and process efficiency.

Implementation Method 1

the metal strip is heated in the furnace using hot air that is blown onto the metal strip by fans

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

the furnace to transfer heat to the metal strip by radiation (e.g. infra-red radiator)

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

electromagnetic effects (e.g. eddy currents, induction)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS10961612B2Method for controlling the coiling temperature of a metal strip
Publication Date: 2021.03.30 ANDRITZ AG
  • US10961612B2 patent drawing

AI summary

A method for coiling a metal strip that is heat-treated in a furnace immediately before coiling and fed to a coiler at an outlet speed, and then coiled at the coiler at an elevated temperature. The future outlet speed of the metal strip and the heat losses from the metal strip between the furnace and the coiler are calculated via a predictive model and the furnace is controlled by the predictive model such that the metal strip is coiled at a pre-defined temperature within a maximum deviation of +/−5° C.