Transport Shell for Induction Heating Without Steel Ingot Scoring

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Solution Overview

Problem

The existing methods for inductive heating of steel blocks in the extrusion process for seamless pipe production result in scoring or grinding marks on the outer surface of steel blocks due to sliding friction, leading to quality defects in the end product.

Innovation Solution

A shell made of non-magnetizable or non-inductive sheet metal is used as a transport shoe for steel blocks, which partially encompasses the contour of the block and features a shoulder that rests against the block to prevent sliding friction, allowing the shell to remain captive and reducing contact with the induction furnace lining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If steel blocks are pushed through the induction furnace on sheet metal strips or round steel rods, then the concrete tube is protected from wear and tear, but scoring or grinding marks form on the outer surface of the steel blocks

Engineering Contradiction:
Improveservice life of concrete tubeVSAvoidsurface quality of steel blocks
Core Design Contradiction:
Duration of action of stationary objectVSManufacturing precision

Solution Approach 1:

A shell made of non-magnetizable or non-inductive sheet metal is introduced as an intermediary transport shoe between the steel block and the concrete tube lining. This shell partially encompasses the steel block contour and features a shoulder that rests against the block, preventing direct contact and sliding friction between the steel block and the concrete tube, thereby eliminating scoring marks while protecting the tube from wear

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful sliding friction contact is extracted by removing the steel block from direct contact with the concrete tube lining. The shell is designed to separate the steel block from the substructure (sheet metal strip or round steel rods), eliminating the source of surface damage while maintaining the protective function for the concrete tube

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If a shell partially encompasses the steel block with a shoulder design, then sliding friction is eliminated and surface quality is improved, but the complexity of the transport device increases

Engineering Contradiction:
Improvesurface quality of steel blocksVSAvoidcomplexity of transport shoe
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The transport shoe is designed as a shell made of thin non-magnetizable or non-inductive sheet metal that partially encompasses the steel block contour. This shell structure provides the necessary protective function while remaining relatively simple in construction, avoiding the need for complex rigid enclosures or multiple components

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

Instead of protecting the steel block surface by using a complex protective coating or cladding on the block itself, the approach is inverted by providing a simple shell structure on the transport device that prevents contact. The protection is achieved through the transport device design rather than modifying the workpiece

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

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 solution eliminates sliding friction and associated surface damage, improving the quality of the steel blocks by maintaining the shell's contact with the block throughout the heating process and simplifying the removal of heated blocks from the base.

Implementation Method 1

inductively preheated to a temperature of approx. 800 °C

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Induction furnaces are used with cylindrical induction coils arranged one behind the other

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Data Source

PatentEP3908797B1Method for inductively heating steel ingots using a shell as transporting shoe and device for carrying out the method
Publication Date: 2023.07.19 SMS GROUP GMBH
  • EP3908797B1 patent drawingFigure 1a~4
  • EP3908797B1 patent drawingFigure 5~6
  • EP3908797B1 patent drawingFigure 7~8

AI summary

The invention relates to a shell (10) as a transporting shoe for steel ingots, which are pushed through a preferably tubular induction furnace for inductive heating for the purpose of producing seamless tubes by the extrusion process, wherein the shell (10) is formed in such a way that it partially reaches around the contour of the steel ingot to be heated, and the shell is provided at one end, leading in the pushing-through direction or transporting direction, with a shoulder (12), which extends at an angle to the transporting direction and against which the steel ingot lies in such a way that the pushed-through steel ingot takes the shell (10) along with it. The invention also relates to a method for inductively heating steel ingots using a shell (10) according to the invention and to a device for carrying out the method.