Metallurgical Furnace Stave Protection With Offset Inserts

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Solution Overview

Problem

Conventional stave protection systems in metallurgical furnaces face challenges with abrasive wear, leading to premature replacement and increased downtime due to insufficient wear resistance, despite existing solutions like refractory/ceramic linings and claddings which may compromise thermal performance and accretion layer formation.

Innovation Solution

A stave protection system featuring rows of grooves with offset inserts and inclined flow guiding surfaces that distribute and trap burden material, extending the service life by promoting a protective accretion layer formation while maintaining thermal efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a refractory/ceramic wear lining is installed in or in front of the stave, then wear resistance is improved, but thermal performance deteriorates due to lower thermal conductivity of refractory materials compared to copper

Engineering Contradiction:
Improvewear resistanceVSAvoidthermal performance
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The stave front face is segmented into multiple grooves containing discrete inserts rather than using a continuous refractory lining. This segmentation allows the copper base material to remain exposed between inserts, maintaining thermal pathways while providing wear protection only where mechanically needed for burden material retention.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Harder insert materials are applied locally within grooves at specific positions on the stave front face, rather than covering the entire surface. This localized approach provides wear resistance precisely where burden material accumulation is needed, while preserving the thermal conductivity of copper in the intervening areas.

Inventive Principle:
Principle #3Local quality

2Strength

If metal inserts are provided in the grooves to protect ribs from erosion, then wear resistance is improved, but thermal performance deteriorates because the inserts are made of less conductive material than the copper stave body

Engineering Contradiction:
Improvewear resistanceVSAvoidthermal performance
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

Metal inserts are placed only in specific grooves rather than all grooves, and not every insert needs to extend to the full depth or width. This partial application provides sufficient wear protection in high-wear zones while minimizing thermal interference. The spacing and dimensions are optimized to provide just enough protection without excessive material that would impede heat transfer.

Inventive Principle:
Principle #16Partial or excessive action

3Duration of action of stationary object

If the stave service life is extended by improving wear resistance, then productivity is improved, but device complexity increases due to additional components like inserts, grooves, and cladding

Engineering Contradiction:
Improvestave service lifeVSAvoidstructure complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The protection system is segmented into standardized groove features and interchangeable inserts that can be manufactured separately and assembled. This modularity simplifies manufacturing and maintenance compared to monolithic refractory linings, as inserts can be replaced independently without replacing the entire stave.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of adding complex external protective structures, the solution inverts the approach by machining grooves directly into the stave face and using simple inserts that fit within these grooves. This integrated design reduces overall complexity compared to separate cladding systems or refractory brickwork.

Inventive Principle:
Principle #13The other way round (Inversion)

4Strength

If burden material is trapped between inserts to protect the stave, then wear resistance is improved, but the inserts may be prone to distortion and buckling under the weight and pressure of the burden material

Engineering Contradiction:
Improvewear resistanceVSAvoidinsert structural stability
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The inserts are nested within grooves that are machined into the stave body, providing mechanical support and constraint. The groove walls act as reinforcing structures that prevent insert distortion and buckling under burden material weight, while the insert protrudes slightly to provide the necessary wear protection surface.

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

The system effectively distributes and traps burden material, reducing wear and extending stave service life by promoting a protective accretion layer, while maintaining thermal performance and preventing premature wear.

Implementation Method 1

cause a flow of furnace burden material, under gravity, to flow in a direction having a component in each of the X and Y directions

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

wear of the staves is reduced by forming a frozen accretion layer on the front face of the stave during operation

Methodology Applied
Scientific EffectFreezing: Freezing

Data Source

PatentEP3765641B1Stave protection system
Publication Date: 2022.07.13 PRIMETALS TECH
  • EP3765641B1 patent drawingFigure 1
  • EP3765641B1 patent drawingFigure 2
  • EP3765641B1 patent drawingFigure 3

AI summary

A stave protection system for a metallurgical furnace comprises: a stave comprising a front face having an X direction and a Y direction which is perpendicular to the X direction such as to define an X-Y plane, the front face comprising rows of grooves which extend in the X direction; and inserts which are slidingly received by the grooves, the inserts so received by each respective groove being spaced apart from each other along the groove, the centres of the inserts which are received by one of the grooves being offset in each of the X and Y directions from the centres of the inserts which are received by an adjacent groove, each of the inserts projecting from the front face of the stave and comprising flow guiding surfaces which are inclined with respect to each of the X and Y directions in the X-Y plane, such that in use the offsets of the inserts in each of the X and Y directions and the inclined flow guiding surfaces cause a flow of furnace burden material, under gravity, to flow in a direction having a component in each of the X and Y directions, so as to distribute the burden material between the inserts over the front face of the stave and/or trap the burden material between the inserts.