Steel Preheating Fluidized Bed Energy Reduction

Solution Overview

Problem

The high energy consumption and subsequent greenhouse gas emissions associated with reheating semi-finished steel products before forming or heat treatment pose a significant environmental concern in steel production.

Innovation Solution

A method involving a pre-heating step using a fluidized bed chamber with solid particles and a heat exchanger, where a gas is injected to form a fluidized bed, and the semi-finished steel product is heated to 200-1000°C, followed by a furnace heating to 1100-1400°C, utilizing renewable energy and waste heat to reduce energy requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If semi-finished steel products are reheated in a furnace from room temperature to above 1000°C, then the steel product reaches the required temperature for forming processes, but a great amount of energy is consumed leading to greenhouse gas emissions

Engineering Contradiction:

Improvesteel product temperatureVSAvoidenergy consumption

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The steel product is pre-heated in a fluidized bed before entering the furnace for final heating. This preliminary heating action reduces the temperature differential that the furnace must overcome, thereby reducing the energy consumption and greenhouse gas emissions associated with reheating the steel product to the required forming temperature

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention changes the heating parameters by introducing a two-stage heating process: first heating the steel product to 200-1000°C in a fluidized bed using relatively low-energy inputs, then completing the heating to above 1000°C in the furnace. This parameter change in heating approach significantly reduces the overall energy consumption compared to direct furnace heating from room temperature

Inventive Principle:

Principle #35Parameter changes

2Temperature

If semi-finished steel products are reheated in a furnace from room temperature to above 1000°C, then the steel product reaches the required temperature for forming processes, but greenhouse gas emissions increase

Engineering Contradiction:

Improvesteel product temperatureVSAvoidgreenhouse gas emissions

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The steel product is pre-heated in a fluidized bed before entering the furnace for final heating. This preliminary heating action reduces the temperature differential that the furnace must overcome, thereby reducing the energy consumption and greenhouse gas emissions associated with reheating the steel product to the required forming temperature

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention changes the heating parameters by introducing a two-stage heating process: first heating the steel product to 200-1000°C in a fluidized bed using relatively low-energy inputs, then completing the heating to above 1000°C in the furnace. This parameter change in heating approach significantly reduces the overall energy consumption and associated greenhouse gas emissions compared to direct furnace heating from room temperature

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

This method significantly reduces energy consumption and greenhouse gas emissions by efficiently pre-heating semi-finished steel products using renewable energy sources and waste heat, preparing them for hot rolling while minimizing environmental impact.

Implementation Method 1

injecting a gas into said first chamber so as to form a first fluidized bed

Methodology Applied

Scientific EffectFluidized bed: Fluidisation

Implementation Method 2

said fluidized bed is able to transfer heat to said semi-finished steel product

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

heating said fluidized bed by means of said heat exchanger

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 4

heating said semi-finished steel product to a temperature from 1100 to 1400°C

Methodology Applied

Scientific EffectThermal heating: Heating

Data Source

PatentUS20250019784A1Heating method of a metallic product

Publication Date: 2025.01.16 ARCELORMITTAL SA

AI summary

A method for heating a semi-finished steel product, including a pre-heating step, performed in a pre-heating device including a chamber containing solid particles, a heat exchanger, a support able to support the semi-finished steel product, a gas injector, and a heating step, performed in a furnace, wherein, the pre-heating step includes the steps of i. injecting a gas into the first chamber so as to form a first fluidized bed, ii. heating the fluidized bed by the heat exchanger, iii. putting the semi-finished steel product, into the fluidized bed and onto the support such the fluidized bed is able to transfer heat to the semi-finished steel product, iv. taking out the semi-finished steel product when its temperature is from 200° C. to 1000° C., and the heating step includes the step heating the semi-finished product to a temperature from 1100 to 1400° C.