Water-Cooled Fuel Feed Support Sealing for Electric Arc Furnaces

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Solution Overview

Problem

Electric arc furnaces face issues with smoke emission and bearing damage due to heat and slag spatter, which can lead to blockages and lining failure, necessitating effective protection of the furnace lining and environment during operation.

Innovation Solution

A water-cooled fuel supply support with a drive unit and sealing elements made of metallic bristles, positioned in the movement joint between the frame box and the fuel supply support, adjusts based on mass-specific energy and arc stability to prevent smoke emission and protect the lining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a movable fuel supply support is used to adjust fuel supply during different operating phases, then fuel supply adaptability is improved, but sealing at the movement joint becomes difficult and smoke emission increases

Engineering Contradiction:
Improvefuel supply adaptabilityVSAvoidsmoke emission
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent uses flexible sealing bristles made of metallic material (stainless steel or Inconel) that can bend and deform to seal the movement joint between the frame box and fuel supply support. These bristles form a flexible barrier that prevents smoke leakage while allowing the fuel supply support to move between different operating positions for adapting fuel supply during charging, melting, and refining phases.

Inventive Principle:
Principle #30Flexible shells and thin films

2Productivity

If the fuel supply support is positioned close to the furnace lining for effective fuel supply, then fuel supply efficiency is improved, but the lining becomes vulnerable to heat and slag spatter damage

Engineering Contradiction:
Improvefuel supply efficiencyVSAvoidheat and slag spatter damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a water-cooled frame box as an intermediary between the fuel supply support and the furnace lining. This frame box acts as a thermal barrier that protects the lining from heat and slag spatter while still allowing effective fuel supply to the charge material. The cooling water circulating through the frame box absorbs heat, preventing damage to the lining and extending its service life.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If the sealing joint is made robust to prevent smoke emission, then sealing effectiveness is improved, but the movement joint becomes complex and maintenance difficult

Engineering Contradiction:
Improvesmoke emission preventionVSAvoidmovement joint complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses relatively simple, replaceable sealing bristles made of inexpensive metallic material that can be easily installed and replaced. Instead of creating a complex permanent sealing mechanism, the design employs simple brush-style seals that can be quickly swapped during maintenance, reducing both the complexity of the movement joint and the time required for maintenance operations.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 solution effectively prevents smoke emission and bearing damage by sealing the movement joint with metallic bristles, ensuring continuous operation and reducing maintenance downtime by minimizing wear on the furnace lining.

Implementation Method 1

At least one sealing element (121) is arranged in the movement joint (91) between the frame box (61) and the fuel supply support (81). The sealing element (121) comprises bristles (125) made of a metallic material.

Methodology Applied
Scientific EffectSealing:

Implementation Method 2

a water-cooled fuel supply support (81) that is movably mounted relative to this, with a drive unit (101) for the fuel supply support (81)

Methodology Applied
Scientific EffectWater cooling: Cooling

Data Source

PatentEP2839043B1Insert assembly having a frame box and fuel feed support, electric arc furnace equipped with said assembly and method for operating an electric arc furnace of this type
Publication Date: 2016.03.23 BADISCHE STAHL ENG GMBH
  • EP2839043B1 patent drawingFigure 1~2
  • EP2839043B1 patent drawingFigure 3~4
  • EP2839043B1 patent drawingFigure 5~6

AI summary

The invention relates to an insert assembly for an electric arc furnace, which has a cooled frame box and a water-cooled fuel feed support movably mounted relative to the frame box. The invention also relates to an electric arc furnace having an assembly of this type and to a method for operating an electric arc furnace. The frame box has a drive unit for the fuel feed support. The sealing element comprises brushes made of a metal material. The length of the individual brushes corresponds to at least three times the width of the expansion joint. In addition, the sealing brushes are oriented toward the interior of the furnace. During the operation of the electric arc furnace, the fuel feed support is adjusted on the basis of the mass-specific introduced energy and the degree of stability of the arc. Upon the introduction of additional fuels through the lateral wall, the present invention provides permanent and effective protection for the lining of the furnace vessel and the environment.