Tandem Rolling Mill Reduction Shifting for Temperature Uniformity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Tandem rolling mills face challenges in maintaining consistent material temperature across the length of the material during the rolling process, affecting mechanical properties and efficiency.

Innovation Solution

A closed loop temperature control system that uses dynamic information to adjust thickness reduction between rolling stands, employing sensors, controllers, and actuators to regulate temperature through acceleration, steady state, and deceleration stages, with optional heat extraction media for precise temperature control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If thickness reduction is increased in early stands to improve productivity, then rolling speed can be increased, but temperature becomes non-uniform across the material length

Engineering Contradiction:
Improverolling speedVSAvoidtemperature uniformity
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent implements dynamic adjustment of thickness reduction at each stand based on real-time temperature measurements. The reduction percentage is not fixed but varies dynamically during the rolling process to maintain temperature uniformity while achieving high rolling speeds. This is achieved through a control system that continuously monitors temperature and adjusts reduction accordingly.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs a feedback control system where temperature sensors continuously measure the material temperature after each stand, and this information is fed back to adjust the thickness reduction at subsequent stands. This closed-loop control ensures that temperature uniformity is maintained while allowing high productivity, as the system automatically compensates for temperature variations caused by high-speed rolling.

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If temperature control is tightly maintained throughout the process, then mechanical properties become uniform, but system complexity increases due to multiple sensors and control mechanisms

Engineering Contradiction:
Improvemechanical properties uniformityVSAvoidcontrol system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent divides the rolling process into discrete segments (stands), with temperature measurement and control at each segment. This segmentation allows for localized temperature control without requiring complex system-wide control, as each stand can be independently monitored and adjusted. The modular approach simplifies the overall control architecture while achieving uniform mechanical properties.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control system uses the natural heat generation from the rolling process itself to maintain temperature uniformity, rather than requiring external heating or cooling systems. By adjusting thickness reduction, the process self-regulates temperature, eliminating the need for complex thermal management equipment while ensuring uniform mechanical properties.

Inventive Principle:
Principle #25Self-service

3Temperature

If thickness reduction is adjusted dynamically to control temperature, then temperature uniformity improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improvetemperature uniformityVSAvoidthickness control precision
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent calculates and sets the inter-stand thickness based on the target final thickness and expected reduction at each stand before rolling begins. This preliminary planning allows the dynamic adjustment of thickness reduction to occur within predetermined boundaries, maintaining temperature uniformity while ensuring that final thickness specifications are met with high precision.

Inventive Principle:
Principle #10Preliminary action

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 ensures consistent yield strength and mechanical properties across the material length by dynamically shifting thickness reduction to maintain uniform temperature, improving process efficiency and reducing costs.

Implementation Method 1

the material generally has a temperature that is greater than room temperature due to heat generated during the rolling process

Methodology Applied
Scientific EffectMechanical deformation heating: Viscous Heating

Data Source

PatentEP3089833B2Dynamic shifting of reduction (DSR) to control temperature in tandem rolling mills
Publication Date: 2022.08.10 NOVELIS DO BRASIL
  • EP3089833B2 patent drawingFigure 1
  • EP3089833B2 patent drawingFigure 2
  • EP3089833B2 patent drawingFigure 3

AI summary

A closed loop temperature control system for use in tandem rolling mills 100. The closed loop temperature control system uses dynamic information about the temperature of the material 108 moving through the mill 100 to adjust the work rolls 118, 120, 130, 132 to adjust the amount of thickness reduction between the stands 102, 104 to control the temperature of the material 108 as it moves through the mill 100. In one embodiment, the control system is configured to eliminate or reduce temperature differences across the length of the material as the material moves through acceleration, steady state, and deceleration stages of the rolling process.