Continuous Casting-Rolling Process for Steel Strip Energy Efficiency

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Solution Overview

Problem

The conventional continuous hot rolling process wastes energy due to inefficient utilization of latent heat from cast blanks, and the continuous casting-rolling process based on thin blanks has limitations in yield, flexibility, and product quality, leading to high costs and inflexibility in production.

Innovation Solution

A continuous casting-rolling process that maximizes the utilization of latent heat by direct loading of cast blanks at high temperatures into compact, staggered heating furnaces, allowing for continuous rolling and flexible production, with features like walking beam type short heating furnaces and hot coiling techniques to achieve high-yield, high-strength steel production with reduced energy consumption and floor area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional continuous hot rolling process is used, then good surface quality and high flexibility are achieved, but latent heat of cast blanks cannot be utilized adequately causing fuel waste

Engineering Contradiction:
Improvefuel consumptionVSAvoidproduction flexibility
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent merges continuous casting with rolling operations into an integrated continuous casting-rolling process. Cast blanks are directly loaded into heating furnaces without offline recombination, combining two previously separate processes into one continuous operation that preserves thermal energy while maintaining production flexibility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements preliminary planning of heating and rolling sequences before production begins. Cast blanks are pre-arranged in heating furnaces according to planned orders, allowing latent heat utilization while maintaining the ability to adapt to different customer requirements through advance scheduling.

Inventive Principle:
Principle #10Preliminary action

2Loss of energy

If continuous casting-rolling process based on thin blanks is used, then latent heat utilization is maximized and fuel is saved, but rolling machine yield is severely limited and electric energy is wasted

Engineering Contradiction:
Improvefuel consumptionVSAvoidrolling machine yield
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent introduces dynamic planning and scheduling systems that allow the production process to adapt in real-time. The rolling machine can dynamically adjust its operation based on cast blank availability, product requirements, and market demands, maximizing yield while maintaining high latent heat utilization.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes key process parameters including blank thickness, heating temperature, and rolling speed to optimize both energy utilization and production yield. By adjusting these parameters dynamically, the system achieves high fuel efficiency while preventing rolling machine idling.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If continuous casting-rolling process based on thin blanks is used, then constant-speed finish rolling is achieved, but process line rigidity increases and accident dealing becomes difficult

Engineering Contradiction:
Improveorganizing controlVSAvoidaccident response flexibility
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent segments the continuous casting-rolling process into distinct controllable zones including casting, heating, rough rolling, and finish rolling sections. This segmentation allows independent control and monitoring of each zone, maintaining precision while enabling rapid response to accidents in specific areas without affecting the entire line.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediary systems such as buffer zones and control systems between different process sections. These intermediaries provide decoupling that maintains manufacturing precision while allowing flexible accident response and process adjustment without propagating disruptions throughout the entire line.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If continuous casting-rolling process based on thin blanks is used, then ultrafast cooling is achieved, but product surface quality deteriorates and yield-tensile ratio increases

Engineering Contradiction:
Improvehigh-strength steel productionVSAvoidsurface quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies different cooling rates to different regions of the blank. Ultrafast cooling is applied locally to achieve high-strength properties in critical areas, while other regions receive controlled cooling to maintain good surface quality. This spatial variation in cooling quality optimizes both strength and surface properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements periodic cooling cycles with varying intensities. Alternating between ultrafast cooling periods for strength development and gentler cooling periods for surface quality maintenance, this periodic action achieves both high-strength steel production and acceptable surface finish.

Inventive Principle:
Principle #19Periodic 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

This process achieves a significant reduction in energy consumption, increases yield, and enhances production flexibility and product quality, enabling the production of various steel types with improved surface quality and economic benefits.

Implementation Method 1

heating the cast blank to a high temperature in a heating furnace

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

the latent heat of the continuous cast blanks cannot be utilized adequately

Methodology Applied
Scientific EffectLatent heat: Latent Heat

Data Source

PatentEP2174728B1A high efficient, energy-saving process of continuous casting-rolling of the strip steels
Publication Date: 2011.08.31 BAOSHAN IRON & STEEL CO LTD
  • EP2174728B1 patent drawingFigure 1~2
  • EP2174728B1 patent drawingFigure 3~4
  • EP2174728B1 patent drawingFigure 5~6

AI summary

A high efficient, energy-saving process of continuous casting-rolling of the strip steels includes the following steps: continuous casting the blanks, cutting the casting blanks, transfering the casting blank to a heating furnaces by a roller track, heating the casting blanks, dephosphorizing the casting blanks, rough rolling, cutting the heads and the ends, finishing, cooling and curling. The continuous casting step is provided with at least two casting liquids, and is provided with at least two furnaces for the casting blanks heating. Said furnaces are interlaced arranged in the both sides of the rolling line. The invention realizes four casting liquids entering into a rolling line, and they are continuous rolled at a same high temperature, thus the throughput of CCM and the rolling mill is highly matching.