Bar Conveyor Furnace Beam With Protruding Inserts

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Solution Overview

Problem

Beam conveying stoves in bar production ovens face issues with thermal loading, corrosion, and mechanical damage due to high temperature differences between hot beams and aluminum-silicon-coated steel sheets, leading to production interruptions and increased costs.

Innovation Solution

A beam design featuring a hollow profile with insert parts that protrude to reduce contact area with the heating material, made from ceramic or metallic materials, and optionally coated with fiber material to absorb melted AISI, allowing for easy exchange and reduced heat transfer and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the beam contact area with the heated material is increased, then the support stability is improved, but the heat transfer and thermal stress on the beam increase

Engineering Contradiction:
Improvesupport stabilityVSAvoidheat transfer
Core Design Contradiction:
Stability of the object's compositionVSTemperature

Solution Approach 1:

The beam surface is segmented into multiple discrete support elements (protrusions, ribs, or localized zones) rather than a continuous contact surface. This segmentation allows the beam to provide stable support through multiple discrete points while minimizing the total contact area, thereby reducing heat transfer and thermal stress accumulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The beam structure incorporates localized high-contact-area regions (protrusions or ribs) at specific support points, while the remaining beam surface maintains low contact area. This local quality differentiation ensures adequate support stability at critical locations while minimizing overall heat transfer.

Inventive Principle:
Principle #3Local quality

2Temperature

If the beam material is made from ceramic for high temperature resistance, then the temperature resistance is improved, but the manufacturing complexity and cost increase

Engineering Contradiction:
Improvetemperature resistanceVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The beam employs composite construction combining ceramic materials (for high-temperature resistance in contact zones) with metallic materials (for structural support and ease of manufacturing). This composite approach achieves the required temperature resistance while maintaining manufacturing feasibility and reducing overall complexity compared to full ceramic construction.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The beam design accepts that ceramic components may have limited service life due to thermal cycling and contact corrosion, planning for periodic replacement. This approach uses durable ceramic materials where needed while accepting replacement as part of the operational cycle, balancing performance requirements with manufacturing considerations.

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

3Ease of manufacture

If the beam is made from metallic material for cost reasons, then the manufacturing cost is reduced, but the resistance to contact corrosion from AlSi coating decreases

Engineering Contradiction:
Improvemanufacturing costVSAvoidcorrosion resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The beam design introduces an intermediary protective layer (fiber coating or refractory material) between the metallic beam substrate and the AlSi-coated steel sheets. This intermediary layer prevents direct contact corrosion while allowing the economical metallic material to serve as the structural base, thus maintaining both cost-effectiveness and corrosion resistance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective coating or fiber layer is applied selectively to the beam surfaces that contact the AlSi-coated sheets, while other beam portions remain as bare metallic material. This localized protection strategy provides adequate corrosion resistance where needed while minimizing manufacturing cost.

Inventive Principle:
Principle #3Local quality

4Temperature

If the contact area between beam and material is reduced using protrusions, then the heat transfer is minimized, but the support surface area decreases

Engineering Contradiction:
Improveheat transferVSAvoidsupport surface area
Core Design Contradiction:
TemperatureVSArea of stationary object

Solution Approach 1:

Instead of reducing the beam surface area to minimize contact, the design inverts the approach by creating protrusions that concentrate support functions into localized regions. The protrusions have small contact areas with the material but provide adequate support through their structural configuration and strategic positioning.

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

Solution Approach 2:

The support function is segmented into multiple discrete protrusions distributed across the beam surface. While each protrusion has a small contact area, the collective support capacity of multiple protrusions provides adequate overall support while maintaining minimal total heat transfer.

Inventive Principle:
Principle #1Segmentation

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 design minimizes heat transfer and corrosion, reducing the risk of beam damage, lowering production costs, and minimizing production interruptions by allowing for easier maintenance and replacement of damaged components.

Implementation Method 1

a layer of fibrous material (20) is arranged on the outer surface (6) which can absorb and bind molten AlSi

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

the contact area between the material being heated and the base body (2) can be reduced by means of the inserts (21)

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

differences in the coefficient of expansion between the beam matrix, infiltrated AISi and corrosion-related reaction products lead to thermal stresses and, due to the large temperature difference between the beam and colder sheet metal parts, to spalling on the beam surface

Methodology Applied
Scientific EffectThermal stress: Thermal Expansion

Data Source

PatentEP3884231B1Bar for bar conveyor furnace, method of manufacture and use of the bar
Publication Date: 2022.11.23 SAINT GOBAIN INDUSTRIE KERAMIK RODENTAL GMBH
  • EP3884231B1 patent drawingFigure 1a~1c
  • EP3884231B1 patent drawingFigure 2a~2b
  • EP3884231B1 patent drawingFigure 2c~2d

AI summary

The invention relates to a bar for a bar-type conveyor furnace, for placement of a heat-treatment item, comprising a longitudinal main part with one or more receiving portions, an insert part being received in each of said receiving portions and protruding in relation to the longitudinal main part such that they form, together, a support for said heat-treatment item.