Segmented Electromagnetic Coils for Uniform Heating

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Solution Overview

Problem

Existing electromagnetic heating devices in cooking appliances suffer from inadequate effective heating area and heating over-concentration due to eddy-current concentration of the magnetic field, leading to inefficient cooking experiences.

Innovation Solution

The arrangement of multiple first electromagnetic coils on a coil disk, with a second coil between and a third coil surrounding them, enhances magnetic field strength and coverage, forming multiple heating centers and increasing the effective heating area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a circular magnetic field heating coil is used, then the heating appliance has a circular heating area, but the heating area cannot cover the projection area of the appliance and the heating area is smaller than the effective area of the coil surface

Engineering Contradiction:
Improveheating areaVSAvoidheating efficiency
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The patent divides the single circular heating coil into multiple segmented coil units arranged in a matrix pattern. This segmentation allows the magnetic field to be distributed across multiple discrete heating zones, enabling the heating area to cover the entire projection area of the appliance while maintaining efficient heat generation through each coil segment.

Inventive Principle:
Principle #1Segmentation

2Shape

If the heating coil is wound in circle, then the cooking appliance has a circular heating area, but eddy-current concentration occurs leading to heating over-concentration

Engineering Contradiction:
Improvecircular heating areaVSAvoidheating over-concentration
Core Design Contradiction:
ShapeVSObject-generated harmful factors

Solution Approach 1:

By segmenting the continuous circular coil into discrete coil units arranged in a matrix, the patent eliminates the continuous circular path that causes eddy-current concentration. Each segmented coil generates its own localized magnetic field, distributing eddy currents across multiple independent zones and preventing harmful concentration effects while maintaining the overall circular heating area shape.

Inventive Principle:
Principle #1Segmentation

3Stability of the object's composition

If multiple first electromagnetic coils are distributed and spaced apart, then heating uniformity is improved, but the effective heating area may be reduced

Engineering Contradiction:
Improveheating uniformityVSAvoideffective heating area
Core Design Contradiction:
Stability of the object's compositionVSArea of stationary object

Solution Approach 1:

The patent combines multiple spaced-apart first electromagnetic coils with second electromagnetic coils positioned in the gaps between them. This merging of coil systems creates a continuous magnetic field coverage across the entire heating area, ensuring both heating uniformity through distributed coils and sufficient effective heating area through the complementary second coils that fill the spaces between first coils.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration improves heating uniformity and power by increasing the coupling coefficient between the magnetic field and the cooking appliance, resulting in a larger effective heating area and enhanced cooking performance.

Implementation Method 1

magnetic field heating coil widely used

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

eddy-current concentration of the magnetic field

Methodology Applied
Scientific EffectEddy current: Eddy Currents

Implementation Method 3

heating over-concentration

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3796756B1Electromagnetic heating device and cooking appliance
Publication Date: 2024.01.10 FOSHAN SHUNDE MIDEA ELECTRICAL HEATING APPLIANCES MFG CO LTD
  • EP3796756B1 patent drawingFigure 1
  • EP3796756B1 patent drawingFigure 2
  • EP3796756B1 patent drawingFigure 3

AI summary

Disclosed are an electromagnetic heating device and a cooking appliance. The electromagnetic heating device includes a coil disk and electromagnetic coils arranged on the coil disk. The electromagnetic coils includes first electromagnetic coils distributed and spaced on the coil disk to correspondingly form multiple magnetic field centers. The problem of heating over-concentration can be solved. And the electromagnetic coils further includes a second electromagnetic coil and/or a third electromagnetic coil. The second electromagnetic coil is arranged in a space area between the first electromagnetic coils, and the third electromagnetic coil is wound around at least two of the first electromagnetic coils. Heating power can be further increased by arranging the second electromagnetic coil and/or the third electromagnetic coil.