Inductive Heating Circuit for Compact Aerosol Substrate Warm-Up
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for an induction heating device capable of heating aerosol-forming substrates, including a susceptor, without an external power supply, and that is compact, easy to use, and can rapidly generate heat for on-demand aerosol production.
Innovation Solution
The inductive heating device includes a DC power source, power supply electronics with a DC/AC inverter and Class-E power amplifier, and a cavity for inductive coupling with the susceptor, allowing for efficient heat transfer and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a conventional combustion process is used to heat the aerosol-forming substrate, then the substrate can be heated to high temperatures, but the device size becomes large and requires external power supply connection
Solution Approach 1:
The patent replaces the conventional mechanical combustion heating system with an electromagnetic induction heating system. The induction heating device uses a magnetic field generated by a coil to induce eddy currents in a susceptor, which generates heat through resistive heating. This substitution eliminates the need for external power supply connections and reduces device size while achieving the required heating temperatures for aerosol formation.
Solution Approach 2:
The induction heating system uses periodic alternating current through the heating coil to generate a time-varying magnetic field. This periodic action induces eddy currents in the susceptor, which continuously generate heat as long as the alternating current is applied. The periodic nature of the AC power allows for rapid heating while maintaining compact device dimensions.
2Ease of operation
If the device is made compact and portable, then ease of use improves, but the ability to rapidly generate sufficient heat for aerosol production deteriorates
Solution Approach 1:
The patent uses a susceptor with specific material parameters (high electrical conductivity and high magnetic permeability) to enhance the efficiency of electromagnetic energy conversion to heat. The susceptor geometry and composition are optimized to maximize eddy current generation and minimize heat losses, enabling rapid temperature rise in a compact device. The LC resonant circuit is tuned to operate at an optimal frequency that maximizes power transfer to the susceptor.
Solution Approach 2:
The heating system employs a composite structure consisting of the induction coil, LC resonant circuit, and specially designed susceptor. The susceptor itself may be a composite material combining conductive and magnetically permeable properties. This composite approach allows the compact device to achieve rapid heating by synergistically combining multiple functional materials and structures.
3Volume of moving object
If the power supply electronics operate at high frequency, then the device size is reduced, but the complexity of the power conversion circuitry increases
Solution Approach 1:
The LC circuit serves multiple functions: it acts as a resonant circuit to generate the alternating magnetic field, functions as an impedance matching network to maximize power transfer to the susceptor, and provides frequency selection to operate at the optimal heating frequency. This multi-functionality reduces the need for separate components, thereby reducing overall device volume while managing complexity.
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 device efficiently heats the susceptor to temperatures of 350-400 degrees Celsius in under five seconds, achieving rapid and effective aerosol production while maintaining a small, user-friendly size.
Implementation Method 1
the inductor of the LC load network is inductively coupled to the susceptor of the aerosol-forming substrate during operation
Implementation Method 2
an alternating magnetic field is induced in the susceptor. This induced alternating magnetic field generates heat in the susceptor
Implementation Method 3
at least some of this heat generated in the susceptor is transferred from the susceptor to the aerosol-forming substrate arranged in thermal proximity to the susceptor
Data Source
AI summary
An inductive heating device (1) comprisesa device housing (10)a DC power source (11),a power supply electronics (13) comprising a DC/AC inverter (132) including a Class-E power amplifier with a transistor switch (1320), a transistor switch driver circuit (1322), and an LC load network (1323) configured to operate at low ohmic load (1324), the LC load network (1323) comprising a shunt capacitor (C1) and a series connection of a capacitor (C2) and an inductor (L2), anda cavity (14) arranged in the device housing (10), the cavity (14) having an internal surface shaped to accommodate at least a portion of the aerosol-forming substrate (20), wherein the cavity (14) is arranged such that the inductor (L2) is inductively coupled to the susceptor (21) of the aerosol-forming substrate (20) during operation.