Cold Crucible Cooling Manifold with Offset Cavities

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Solution Overview

Problem

Existing cold crucibles for induction heating devices face issues with limited service life due to solder deterioration, contamination, and leaks, which complicates maintenance and hinders the production of high-purity materials.

Innovation Solution

A cold crucible design featuring a one-piece structure with longitudinal coolant channels and a connection ring that eliminates the need for brazing, allowing for easier assembly and disassembly, and a cooling manifold with offset collector cavities to prevent leaks and facilitate maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If brazing is used to connect cooling tubes to the crucible, then the crucible can be assembled, but the brazings deteriorate over time causing contamination, sealing defects, and limited lifespan

Engineering Contradiction:
Improveassembly of cooling tubesVSAvoidsealing and contamination resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The crucible is divided into multiple sector-shaped sections that are electrically isolated from each other. Each section can be independently assembled and removed, allowing the cooling manifold to be detached without damaging brazed joints. This segmentation eliminates the need for permanent brazing while maintaining structural integrity and sealing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The crucible design transitions from a static brazed structure to a dynamic, reconfigurable system where sectors can be independently positioned and assembled. This allows for easy disassembly and reassembly of the cooling manifold without compromising the sealing or causing contamination, thereby improving reliability and extendable service life.

Inventive Principle:
Principle #15Dynamics

2Power

If the crucible is made of continuous material to prevent magnetic field screening, then magnetic field penetration is improved, but the crucible cannot be electrically isolated into sectors for induction heating

Engineering Contradiction:
Improvemagnetic field penetrationVSAvoidelectrical isolation structure
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The crucible is segmented into multiple electrically isolated sectors that are arranged circumferentially. Each sector is made of electrically conductive material and is separated from adjacent sectors by non-conductive gaps or insulators. This segmentation allows the magnetic field to penetrate through the gaps while each sector can be independently heated by induced eddy currents, resolving the contradiction between magnetic field penetration and electrical isolation.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the crucible is sectored to induce eddy currents and prevent magnetic field shielding, then induction heating efficiency is improved, but the number of brazing joints increases leading to more leaks and maintenance complexity

Engineering Contradiction:
Improveheating efficiencyVSAvoidnumber of brazing joints
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The crucible is divided into multiple sector-shaped sections with air gaps between them, allowing each sector to be independently heated by eddy currents while preventing magnetic field shielding. The sectors are connected to the cooling manifold through a simplified interface that reduces the number of brazing joints required, thereby maintaining heating efficiency while reducing leakage risks and maintenance complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of brazing all cooling tubes to the entire crucible structure, the invention applies brazing only at specific strategic locations where cooling channels intersect with the crucible body. This partial brazing approach maintains the necessary thermal connection while minimizing the number of joints, thus reducing the risk of leaks and simplifying maintenance.

Inventive Principle:
Principle #16Partial or excessive action

4Ease of repair

If the crucible is designed for easy disassembly to simplify maintenance, then maintenance time is reduced, but sealing defects and contamination risks increase

Engineering Contradiction:
Improvemaintenance accessibilityVSAvoidsealing integrity
Core Design Contradiction:
Ease of repairVSReliability

Solution Approach 1:

The crucible is segmented into removable sectors that can be easily detached from the cooling manifold without requiring destruction of brazed joints. Each sector is designed with integrated cooling channels that connect to the manifold through simple mechanical interfaces, allowing for quick disassembly and reassembly while maintaining sealing integrity through precision-machined mating surfaces and gasket systems.

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 solution extends the service life of the crucible, reduces contamination risks, and simplifies maintenance, enabling the production of high-purity materials by maintaining a stable and homogeneous heating process.

Implementation Method 1

The device includes an inductor coil surrounding the crucible to generate a magnetic field inside the crucible and thus heat the load by induction

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The crucible is cooled to dissipate the heat from the load and the Joule effect due to the induced current within it

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

Each section contains a cooling channel through which a coolant circulates to cool the crucible during operation

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

The crucible is cooled to dissipate the heat from the load and the Joule effect due to the induced current within it

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3737901B1Cold crucible and associated cooling manifold for an induction heating device
Publication Date: 2022.02.09 CENT NAT DE LA RECH SCI (C N R S)
  • EP3737901B1 patent drawingFigure 1a~1d
  • EP3737901B1 patent drawingFigure 2a~4
  • EP3737901B1 patent drawingFigure 6a~12

AI summary

The present invention relates to a cold crucible for an induction heating device for heating and melting materials such as metals. The crucible comprises a crucible body that is in the general shape of a tube or of a test piece, the peripheral partition of which comprises a plurality of sections in the shape of arcs of a circle separated from each other by an air space. Each section contains a cooling pipe circulating a coolant in order to cool the crucible during operation. The present invention also relates to a cooling manifold, which, during operation, is connected to the crucible body and which allows the coolant to be distributed through the various pipes. The invention also relates to a method for manufacturing the crucible. The field of the invention is particularly that of metallurgy and foundries.