Induction Aerosol Heating with Opposing Field Leakage Suppression

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Solution Overview

Problem

Induction heating systems for aerosol generating devices face electromagnetic field leakage, which necessitates a solution to reduce user exposure and improve heating control without complex shielding structures.

Innovation Solution

An aerosol generating system incorporating a primary susceptor heated by a primary electromagnetic field and a secondary susceptor that generates a secondary electromagnetic field opposing the primary field, reducing leakage by confining the net field boundary within the device, with the secondary susceptor having lower electrical resistivity to prevent heating and the primary susceptor having higher resistivity for efficient heating, along with an optional electromagnetic shield for enhanced energy transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an induction heating system is used to heat the aerosol generating substrate, then heating control is improved, but electromagnetic field leakage occurs

Engineering Contradiction:
Improveheating controlVSAvoidelectromagnetic field leakage
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A secondary susceptor is introduced as an intermediary component between the inductor and the external environment. This secondary susceptor generates a secondary electromagnetic field that opposes the primary field, acting as a mediator to cancel out field leakage while allowing the primary susceptor to maintain efficient heating control through the primary field.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful electromagnetic field leakage into a beneficial effect by using the same primary electromagnetic field that causes leakage to induce a secondary field in the secondary susceptor. This secondary field, generated under the influence of the primary field, opposes and cancels the leakage, transforming the harmful radiation into a useful shielding mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If a complex electromagnetic shield structure is added to reduce electromagnetic leakage, then electromagnetic field leakage is reduced, but device complexity increases

Engineering Contradiction:
Improveelectromagnetic field leakageVSAvoidshield structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The secondary susceptor is designed to automatically generate the opposing electromagnetic field through the influence of the primary electromagnetic field itself. This self-service mechanism eliminates the need for external power sources, control circuits, or complex active shielding structures, reducing device complexity while maintaining effective leakage reduction.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the electrical resistivity parameter of the secondary susceptor to be lower than that of the primary susceptor. This parameter change enables the secondary susceptor to efficiently conduct the induced currents necessary for generating the opposing field, achieving effective shielding through a simple passive component rather than a complex structure.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If the secondary susceptor has lower electrical resistivity to prevent heating, then electromagnetic field leakage is reduced, but heating efficiency of the primary susceptor must be maintained

Engineering Contradiction:
Improveelectromagnetic field leakageVSAvoidheating efficiency
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent applies different electrical resistivity qualities to different components: the primary susceptor has higher electrical resistivity optimized for efficient heating through electromagnetic induction, while the secondary susceptor has lower electrical resistivity optimized for generating the opposing field without excessive heating. This local differentiation of material properties allows each component to perform its specific function optimally.

Inventive Principle:
Principle #3Local quality

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 reduces electromagnetic leakage, enhances heating control, and minimizes user exposure to electromagnetic fields while maintaining efficient energy transfer to the aerosol generating substrate, ensuring safe and controlled aerosol production.

Implementation Method 1

the primary susceptor is heated by the primary electromagnetic field due to eddy currents and/or magnetic hysteresis losses resulting in a conversion of energy from electromagnetic to heat

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Implementation Method 2

the primary susceptor is heated by the primary electromagnetic field due to eddy currents and/or magnetic hysteresis losses resulting in a conversion of energy from electromagnetic to heat

Methodology Applied
Scientific EffectMagnetic hysteresis: Magnetic Hysteresis

Implementation Method 3

an induction coil (also referred to as an inductor) is provided with the device and a susceptor is provided, for example with the aerosol generating substrate. Electrical energy is provided to the inductor when a user activates the device which in turn generates an alternating electromagnetic field. The susceptor couples with the electromagnetic field and generates heat

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 4

a secondary susceptor configured to solely generate a secondary electromagnetic field acting in opposition to the primary electromagnetic field, wherein the secondary electromagnetic field is generated under the influence of the primary electromagnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 5

heat the aerosol generating substrate, without burning the aerosol generating substrate, to volatise at least one component of the aerosol generating substrate and thereby generate a vapour

Methodology Applied
Scientific EffectVapourisation: Evaporation

Implementation Method 6

generate a vapour which cools and condenses to form an aerosol for inhalation by a user of the device

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP4064912B1Aerosol generating system
Publication Date: 2024.01.03 JT INTERNATIONAL SA
  • EP4064912B1 patent drawingFigure 1
  • EP4064912B1 patent drawingFigure 2a~2c
  • EP4064912B1 patent drawingFigure 3

AI summary

An aerosol generating system (1, 2, 3) comprises an aerosol generating substrate (26), an inductor (29) for generating a primary electromagnetic field (42), a primary susceptor (28) configured to be inductively heated by the primary electromagnetic field (42) and to solely heat the aerosol generating substrate (26), and a secondary susceptor (40) configured to solely generate a secondary electromagnetic field (44). The secondary electromagnetic field (44) is generated under the influence of the primary electromagnetic field (42) and acts in opposition to the primary electromagnetic field (42).