Integrated Annealing and Galvanizing Line for Flexible Steel Production

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Solution Overview

Problem

Existing continuous annealing and galvanizing lines are not adaptable to the evolving market demand for a variety of steel grades and lower tonnages, leading to unprofitable operations and the need for flexible production capabilities without increasing complexity or cost.

Innovation Solution

A combined annealing and galvanizing line is designed where the galvanizing installation is incorporated within the annealing installation, between the overaging and cooling sections, allowing for selective guidance of the strip for either galvanizing or direct cooling, and the line is adapted to maintain profitability by reducing the length of the overaging section and optimizing the running speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate continuous annealing and galvanizing lines are used, then each process can be optimized independently, but the equipment complexity and cost increase significantly

Engineering Contradiction:
Improveprocess optimizationVSAvoidequipment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the continuous annealing line and continuous galvanizing line into a single integrated system. The annealing furnace and galvanizing bath are arranged in sequence within the same production line, allowing both processes to be performed continuously on the steel strip without separate equipment installations. This merging reduces overall equipment complexity while maintaining process optimization capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated line is designed to handle multiple product types and process requirements within a single system. The same production line can process different steel grades, perform both annealing and galvanizing operations, and adjust parameters for various product specifications. This multi-functionality eliminates the need for separate specialized lines while maintaining process quality.

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

2Productivity

If the line is designed for large tonnages with fixed parameters, then profitability is maintained, but adaptability to market changes and product variety is reduced

Engineering Contradiction:
ImprovetonnageVSAvoidproduct variety
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The integrated line incorporates dynamic adjustment capabilities for processing parameters including temperature, line speed, and immersion depth. These parameters can be modified during operation to accommodate different steel grades and product requirements. The system transitions from fixed-parameter design to dynamically adjustable parameters, enabling both high productivity and market adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements the ability to change key process parameters such as annealing temperature, galvanizing temperature, and strip speed without stopping the line. This parameter flexibility allows the system to respond to market demands for product variety while maintaining continuous operation and high productivity levels.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the line is stopped for parameter adjustments, then product quality is maintained, but productivity and profitability decrease

Engineering Contradiction:
Improveproduct qualityVSAvoidproduction continuity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The system allows dynamic parameter adjustments during continuous operation. Temperature controls, speed variations, and process parameter modifications can be implemented without stopping the line, maintaining both product quality and production continuity. This eliminates the need for shutdowns during parameter changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The integrated line is designed to maintain continuous production flow while adapting to different product requirements. The system performs annealing and galvanizing in continuous sequence without interruption, and parameter changes can be made during operation rather than requiring line stoppages, thus preserving both quality and productivity.

Inventive Principle:
Principle #20Continuity of useful action

4Length of stationary object

If a compact integrated line is used, then the overall length is reduced, but the space for each individual process is limited

Engineering Contradiction:
Improveline lengthVSAvoidprocess space
Core Design Contradiction:
Length of stationary objectVSVolume of stationary object

Solution Approach 1:

The patent utilizes three-dimensional space arrangement within the integrated line. The galvanizing bath is positioned to overlap vertically with portions of the annealing furnace, and process sections are arranged in compact configurations that maximize space utilization. This dimensional optimization reduces the overall footprint while providing adequate process space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The design incorporates nested arrangements where certain process components are positioned within or alongside other process sections. The compact integration allows the galvanizing section to be embedded within the overall line structure, optimizing space usage and reducing total line length while maintaining sufficient process volume.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 configuration enables the production of a wide variety of products, maintains profitability of existing lines, and allows for rapid changes in production parameters without increasing the overall length of the line, ensuring efficient annealing and galvanizing processes.

Implementation Method 1

a section (22) for heating and maintaining the annealing temperature

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

in which the strip circulates following a zig-zag path defined by a plurality of deflecting rollers and which successively ensures the heating of the strip

Methodology Applied
Scientific EffectThermal convection: Convection

Implementation Method 3

a rapid cooling section (23), an overaging section (24) and a second slow cooling section (25)

Methodology Applied
Scientific EffectForced convection cooling: Forced Convection

Implementation Method 4

the surface to be galvanized can also be activated by surface chemical migration

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 5

the strip is passed over a roller immersed in a bath of liquid metal

Methodology Applied
Scientific EffectElectroplating: Electroplating

Implementation Method 6

a slow cooling in section (25) which ends, usually, by quenching the strip in a final cooling liquid bath to room temperature

Methodology Applied
Scientific EffectThermal conduction cooling: Conduction (thermal)

Data Source

PatentEP2176438B1Combined annealing and galvanisation line and method for converting a continuous annealing line into such combined line
Publication Date: 2011.01.12 SIEMENS VAI METALS TECHNOLOGIES SAS
  • EP2176438B1 patent drawingFigure 1~5
  • EP2176438B1 patent drawingFigure 3~8
  • EP2176438B1 patent drawingFigure 6~10

AI summary

The invention relates to a combined annealing and galvanisation line of a metal strip (1), that successively comprises an annealing station (2) with an annealing section (22), a quenching section (23), an over-ageing section (26) and a second slow-cooling section (25), and a galvanisation station (4) ending in a tempering bath. According to the invention, the galvanisation station (4) is integrated inside the annealing station (2) between the over-ageing section (26) and the second cooling section (25) and, at the output of the over-ageing section (26), the strip is directed by selective guiding means (80) either to the galvanisation station (4) and directly to the line output device (3), or directly to the second cooling section (25) and the line output device (3). The invention also relates to a particularly simple and economical method for converting an existing continuous annealing line into a combined annealing and/or galvanisation line.