RU2805594C2 - Induction heating layout with gas-permeable segmented induction heating element - Google Patents

Abstract

FIELD: aerosol generation systems.

SUBSTANCE: induction heating element (10) for an aerosol generation system, an induction heating arrangement for an aerosol generation system, an aerosol generator with an induction heating arrangement, and an aerosol generation system with an aerosol generator containing an induction heating arrangement. The induction heating element (10) contains: a cavity (20) for housing an aerosol-generating substrate to be heated by the induction heating element (10); first pantograph (12); second pantograph (14); and an intermediate element (16) located between the first pantograph (12) and the second pantograph (14), wherein the intermediate element (16) is gas-permeable, wherein the intermediate element (16) contains at least one of: thermal insulating material for thermally insulating the first pantograph (12) from the second pantograph (14); and electrical insulating material for electrically isolating the first pantograph (12) from the second pantograph (14).

EFFECT: effective performance.

14 cl, 9 dwg

Description

The present invention relates to an induction heating element for an aerosol generating system, an induction heating arrangement for an aerosol generating system, an aerosol generating device with an induction heating arrangement, and an aerosol generating system with an aerosol generating device comprising an induction heating arrangement. .

The prior art provides a number of electrical aerosol generating systems in which an aerosol generating device having an electrical heater is used to heat an aerosol generating substrate such as a tobacco rod. One of the goals of such aerosol-generating systems is to reduce the amount of known harmful smoke components produced by combustion and pyrolytic degradation of tobacco in conventional cigarettes. Typically, an aerosol-generating substrate is provided as part of an aerosol-generating article that is inserted into a cavity in the aerosol-generating device. In some known systems for heating an aerosol-forming substrate to a temperature at which it is capable of releasing volatile components that can form an aerosol, a resistive heating element, such as a heating plate, is inserted into or located around the aerosol-forming substrate when the product placed in a device that generates an aerosol. Other aerosol generating systems use an induction heater instead of a resistive heating element. The induction heater typically includes an inductor forming part of the aerosol-generating device, and a current collector positioned such that it is in thermal proximity to the aerosol-generating substrate. The inductor generates a varying magnetic field to generate eddy currents and hysteresis losses in the pantograph, causing the pantograph to heat up, thereby heating the aerosol-forming substrate. Induction heating provides the ability to generate an aerosol without the heater affecting the aerosol-generating product. This may increase the ease with which the heater can be cleaned.

Some known aerosol generating devices contain more than one inductor, with each inductor configured to heat a different portion of the current collector. Such aerosol generating devices may be used to heat different parts of the aerosol generating article at different times or to different temperatures. However, for such aerosol generating devices, it may be difficult to heat one portion of the aerosol generating article without indirectly simultaneously heating an adjacent portion of the aerosol generating article.

It would be desirable to provide an aerosol generating device that would mitigate or eliminate these problems with prior art systems.

According to this invention, an induction heating element is provided for an aerosol generating system.

The induction heating element may include a first current collector. The induction heating element may include a second current collector. The induction heating assembly may include an intermediate element located between the first pantograph and the second pantograph. The intermediate element may be gas permeable.

Specifically, according to this invention, there is provided an induction heating element for an aerosol generating system, the induction heating element comprising: a first current collector; second pantograph; and an intermediate element located between the first pantograph and the second pantograph, the intermediate element being gas-permeable.

Providing a gas-permeable intermediate element between the first pantograph and the second pantograph allows air to be drawn through the induction heating element on the intermediate element.

Drawing air through the induction heating element on the intermediate element may provide cooling to the ends of the first pantograph and the second pantograph adjacent to the intermediate element. Cooling the ends of the first pantograph and the second pantograph adjacent to the intermediate member may help selectively heat the aerosol-forming substrate in the region of the first pantograph and in the region of the second pantograph, which is advantageous. When one of the pantographs is heated to a higher temperature than the other pantograph, the gas-permeable intermediate element can help reduce heat transfer from the higher temperature pantograph to the lower temperature pantograph by cooling the adjacent ends of the pantographs as air is drawn through the intermediate member.

According to this invention, an induction heating arrangement is provided for an aerosol generating system.

The induction heating arrangement may include an induction heating element. The induction heating element may include: a first current collector; second pantograph; and an intermediate element located between the first pantograph and the second pantograph. The intermediate element may be gas permeable. The induction heating arrangement may further comprise a first inductor. The induction heating arrangement may further include a second inductor. The first inductor may be positioned relative to the induction heating element such that a varying electric current supplied to the first inductor generates a varying magnetic field that heats the first current collector of the induction heating element. The second inductor may be positioned relative to the induction heating element such that a varying electric current supplied to the second inductor generates a varying magnetic field that heats the second current collector of the induction heating element.

Specifically, according to this invention, there is provided an induction heating assembly for an aerosol generating system, the induction heating assembly comprising: an induction heating element, a first inductor, and a second inductor. The induction heating element contains: a first current collector; second pantograph; and an intermediate element located between the first pantograph and the second pantograph, wherein the intermediate element is gas-permeable. The first inductor is positioned relative to the induction heating element such that a varying electric current supplied to the first inductor generates a varying magnetic field that heats the first current collector of the induction heating element. The second inductor coil is positioned relative to the induction heating element such that a varying electric current supplied to the second inductor coil generates a varying magnetic field that heats the second current collector of the induction heating element.

Inclusion in the induction heating arrangement of a first inductor coil configured to heat the first pantograph of the induction heating element and a second inductor coil configured to heat the second pantograph of the induction heating element allows selective heating of the first pantograph and the second pantograph. Such selective heating allows the induction heating assembly to heat different portions of the aerosol-forming substrate at different times, and may allow one of the susceptors to be heated to a different temperature than the other susceptor.

This invention provides an aerosol generating device comprising an induction heating unit.

The induction heating arrangement may include an induction heating element. The induction heating element may include: a first current collector; second pantograph; and an intermediate element located between the first pantograph and the second pantograph. The intermediate element may be gas permeable. The induction heating arrangement may further comprise a first inductor. The induction heating arrangement may further include a second inductor. The first inductor may be positioned relative to the induction heating element such that a varying electric current supplied to the first inductor generates a varying magnetic field that heats the first current collector of the induction heating element. The second inductor may be positioned relative to the induction heating element such that a varying electric current supplied to the second inductor generates a varying magnetic field that heats the second current collector of the induction heating element.

In particular, this invention provides an aerosol generating device comprising a device housing defining a device cavity for housing an aerosol generating substrate. The aerosol generating device further comprises an induction heating arrangement comprising an induction heating element comprising: a first current collector located around a first cavity portion of the device; a second current collector located around the second part of the device cavity, and an intermediate element located around the intermediate part of the device cavity, between the first part and the second part of the device cavity, wherein the intermediate element is gas-permeable. The aerosol generating device further comprises: a first inductor located around at least a portion of the first susceptor and a first cavity portion of the device; a second inductor located around at least a portion of the second pantograph and a second portion of the device cavity; and a power supply connected to the induction heating arrangement and configured to supply a varying electric current to the first inductor and the second inductor. When a varying electric current is applied to the first inductor, the first inductor generates a varying magnetic field that heats the first current collector. When a varying electric current is applied to the second inductor, the second inductor generates a varying magnetic field that heats the second current collector.

In addition to allowing efficient selective heating of the first portion of the device cavity and the second portion of the device cavity, the gas-permeable intermediate member also allows air to be drawn into the device cavity between the first portion of the device cavity and the second portion of the device cavity. Accordingly, the gas-permeable intermediate member may allow air to be supplied directly to a first portion of the aerosol-forming substrate located in the first portion of the device cavity without the air first passing through a second portion of the aerosol-forming substrate located in the second portion of the device cavity. Likewise, the gas-permeable intermediate member may allow air to be supplied directly to a second portion of the aerosol-forming substrate located in the second portion of the device cavity without the air first passing through the first portion of the aerosol-forming substrate located in the first portion of the device cavity. Supplying air directly to a portion of the aerosol-forming substrate located in one portion of the cavity of the device may provide improved control of the characteristics of the aerosol generated from the aerosol-forming substrate when the portion of the aerosol-forming substrate is heated by one of the current collectors, which is advantageous.

According to this invention, an aerosol generating system is provided. An aerosol-generating system comprises an aerosol-generating article containing an aerosol-generating substrate, and an aerosol-generating device configured to accommodate at least a portion of the aerosol-generating article. The aerosol-generating article may comprise a first aerosol-generating substrate and a second aerosol-generating substrate. The aerosol generating device may include an induction heating unit. The induction heating arrangement may include an induction heating element. The induction heating element may include: a first current collector; second pantograph; and an intermediate element located between the first pantograph and the second pantograph. The intermediate element may be gas permeable. The induction heating arrangement may further comprise a first inductor. The induction heating arrangement may further include a second inductor. The first inductor may be positioned relative to the induction heating element such that a varying electric current supplied to the first inductor generates a varying magnetic field that heats the first current collector of the induction heating element. The second inductor may be positioned relative to the induction heating element such that a varying electric current supplied to the second inductor generates a varying magnetic field that heats the second current collector of the induction heating element. The induction heating arrangement may be configured such that the first susceptor is arranged to heat the first aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is housed in the aerosol-generating device. The induction heating arrangement may be configured such that the second susceptor is arranged to heat the second aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is housed in the aerosol-generating device.

As used herein, the term “aerosol-forming substrate” means a substrate capable of releasing volatile compounds that can form an aerosol. Such volatile compounds can be released by heating the substrate to form an aerosol. The aerosol generating substrate is typically an aerosol generating article.

As used herein, the term “aerosol-generating article” means an article containing an aerosol-forming substrate capable of releasing volatile compounds that can form an aerosol. For example, an aerosol generating product may be one that generates an aerosol that is directly inhaled by a user inhaling or puffing from a mouthpiece at the proximal or user end of the system. The aerosol-generating product may be disposable. An article containing a substrate forming an aerosol containing tobacco may be referred to herein as a tobacco stick.

As used herein, the term “aerosol generating device” refers to a device that interacts with an aerosol-forming substrate to generate an aerosol.

As used herein, the term “aerosol generating system” refers to the combination of an aerosol generating device and an aerosol generating article. In an aerosol generating system, an aerosol generating article and an aerosol generating device cooperate to generate a respirable aerosol.

As used herein, the term "varying current" includes any type of current that changes over time to generate a varying magnetic field. The term "variable current" is intended to include alternating currents. In case the changing current is alternating current, the alternating current generates an alternating magnetic field.

As used herein, the term “length” means the primary dimension in the longitudinal direction of an aerosol generating device or an aerosol generating article or a component of an aerosol generating device or an aerosol generating article.

As used herein, the term “width” means the major dimension in the transverse direction of an aerosol generating device or aerosol generating article, or a component of an aerosol generating device or an aerosol generating article, at a specific location along its length. The term "thickness" means the dimension in the transverse direction perpendicular to the width.

As used herein, the term "cross-section" is used to describe the cross-section of an aerosol generating device or aerosol generating article, or a component of an aerosol generating device or aerosol generating article, in a direction perpendicular to the longitudinal direction at a particular location along its length.

As used herein, the term “proximal” means the user end or mouth end of the aerosol generating device or aerosol generating article. The proximal end of a component of an aerosol generating device or aerosol generating article is the end of the component closest to the user end or mouthpiece end of the aerosol generating device or aerosol generating article. As used herein, the term "far" refers to the end opposite the near end.

The present invention provides an induction heating element for an aerosol generating system.

In some embodiments, the induction heating element may be an internal heating element. As used herein, the term “internal heating element” refers to a heating element configured to be inserted into an aerosol-generating substrate.

The internal heating element is preferably configured to be inserted into the aerosol-forming substrate. The internal heating element may be in the form of a plate. The internal heating element may be in the form of a pin. The internal heating element may be cone-shaped. In the case where the aerosol generating device includes a device cavity for receiving the aerosol generating substrate, preferably an internal heating element extends into the device cavity.

In some embodiments, the induction heating element may be an external heating element. As used herein, the term “external heating element” refers to a heating element configured to heat the outer surface of the aerosol-forming substrate.

The external heating element is preferably configured to at least partially surround the aerosol-forming substrate when the aerosol-forming substrate is placed in the aerosol-generating device.

In some embodiments, the induction heating arrangement includes at least one internal heating element and at least one external heating element.

The induction heating element may include a cavity for housing an aerosol-forming substrate. In particular, if the induction heating element is an external heating element, the induction heating element may include a cavity for housing an aerosol-forming substrate. The induction heating element may be configured to heat the outer surface of the aerosol-forming substrate when the aerosol-forming substrate is placed in the cavity of the induction heating element.

The induction heating element may include an outer side and an inner side opposite the outer side. The inner side may at least partially define a cavity of the induction heating element for housing the aerosol-forming substrate. The intermediate element may be configured to allow air to pass from the outside to the inside. The intermediate element may include one or more air passages configured to allow air to pass from the outside to the inside. One or more air passages may extend from the outside to the inside of the induction heating element.

In some preferred embodiments, the induction heating element is a tubular induction heating element. The inner surface of the tubular induction heating element may define a cavity of the induction heating element. The first susceptor may be a tubular susceptor defining a portion of the cavity of the induction heating element. The second pantograph may be a tubular pantograph defining a portion of the cavity of the induction heating element. The intermediate element may be a tubular intermediate element defining a portion of the cavity of the induction heating element.

In those embodiments where the aerosol generating device includes a device cavity for housing an aerosol generating substrate, the induction heating element may at least partially surround the device cavity. The cavity of the induction heating element may be aligned with the cavity of the device.

The induction heating element contains a first current collector and a second current collector.

As used herein, the term "susceptor" refers to an element containing a material that is capable of converting electromagnetic energy into heat. When the pantograph is placed in a changing magnetic field, the pantograph heats up. Heating of the pantograph may result from at least one of hysteresis losses and eddy currents induced in the pantograph, depending on the electrical and magnetic properties of the pantograph material.

The current collector may comprise any suitable material. The current collector may be made of any material that can be inductively heated to a temperature sufficient to aerosolize the aerosol-forming substrate. Preferred pantographs can be heated to temperatures in excess of about 250 degrees Celsius. Preferred current collectors may be formed from a conductive material. As used herein, the term "electrically conductive" refers to materials having an electrical resistivity of less than or equal to 1 x10 ^-4 ohm-meter (Ohm-m) at twenty degrees Celsius. Preferred current collectors may be formed from a thermally conductive material. As used herein, the term "thermal conductivity material" is used to describe a material having a volumetric thermal conductivity of at least 10 watts per meter-Kelvin (W/(mK)) at 23 degrees Celsius and 50 percent relative humidity when measured using the modified method. transient planar source (MTPS).

Suitable materials for the current collector include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium and composites of metal materials. Some preferred current collectors contain metal or carbon. Some preferred current collectors may contain ferromagnetic material, such as ferritic iron, a ferromagnetic alloy such as ferromagnetic steel or stainless steel, ferromagnetic particles and ferrite. Some preferred current collectors are composed of ferromagnetic material. A suitable pantograph may contain aluminum. A suitable pantograph may consist of aluminum. The pantograph may contain at least about 5 percent, at least about 20 percent, at least about 50 percent, or at least about 90 percent ferromagnetic or paramagnetic materials.

Preferably, the current collector is formed from a material that is substantially impermeable to gas. In other words, preferably the current collector is made of a material that is not permeable to gas.

The current collector of the induction heating element can take any suitable shape. For example, the pantograph may be oblong. The pantograph may have any suitable cross-section. For example, the pantograph may have a circular, elliptical, square, rectangular, triangular, or other polygonal cross-section. The current collector can be tubular. The tubular current collector contains an annular body defining an internal cavity. The cavity of the current collector can be configured to accommodate a substrate that forms an aerosol. The pantograph cavity may be an open cavity. The pantograph cavity may be open at one end. The pantograph cavity can be open at both ends.

If the pantograph is a tubular pantograph having a cavity for housing the aerosol-forming substrate that is open at one end or both ends, it is preferred that the pantograph is substantially gas-tight from an outer surface to an inner surface defining the inner cavity. In other words, preferably the pantograph is substantially impermeable to gas through the side walls of the pantograph.

In some embodiments, all pantographs are substantially identical. For example, the second pantograph may be substantially identical to the first pantograph. All pantographs can be formed from the same material. All pantographs can have the same shape and size. Making each pantograph identical to the other pantographs can ensure that each pantograph is heated to substantially the same temperature and heated at substantially the same rate when a given varying magnetic field is applied.

In some embodiments, the second pantograph differs from the first pantograph in at least one characteristic. The second pantograph may be formed from a material different from the material of the first pantograph. The shape and dimensions of the second pantograph may be different from the shape and dimensions of the first pantograph. The second pantograph may have a length that is greater than the length of the first pantograph. Making each pantograph different from other pantographs can ensure that each pantograph is adapted to optimally heat different aerosol-forming substrates.

In one example, the first aerosol-forming substrate may require heating to a first temperature to generate a first aerosol with the desired characteristics, and the second aerosol-forming substrate may require heating to a second temperature different from the first temperature to generate a second aerosol with the desired characteristics. In this example, the first susceptor may be formed from a first material suitable for heating the first aerosol-forming substrate to a first temperature, and the second susceptor may be formed from a second material different from the first material suitable for heating the second aerosol-forming substrate to second temperature.

In another example, an aerosol-generating article may comprise a first aerosol-generating substrate having a first length, and a second aerosol-generating substrate having a second length different from the first length, such that heating the second aerosol-generating substrate generates a different amount of aerosol, than heating the first aerosol-forming substrate. In this embodiment, the first pantograph may have a length substantially equal to the first length, and the second pantograph may have a length substantially equal to the second length.

In some preferred embodiments, the first pantograph is an elongated tubular pantograph and the second pantograph is an oblong tubular pantograph. In these preferred embodiments, the first pantograph and the second pantograph may be substantially aligned. In other words, the first pantograph and the second pantograph may be coaxially aligned.

The induction heating element may contain any suitable number of current collectors. The induction heating element contains a plurality of current collectors. The induction heating element contains at least two current collectors. For example, an induction heating element may contain three, four, five or six current collectors. If the induction heating element contains more than two pantographs, an intermediate element may be placed between each adjacent pair of pantographs.

In some preferred embodiments, the pantograph may comprise a pantograph layer provided on the support body. Each of the first pantograph and the second pantograph may be formed from a support body and a pantograph layer. The placement of a pantograph in a changing magnetic field causes eddy currents in the immediate vicinity of the surface of the pantograph, an effect called the skin effect. Accordingly, it is possible to form a susceptor from a relatively thin layer of susceptor material, which at the same time ensures efficient heating of the susceptor in the presence of a changing magnetic field. Constructing the susceptor from a support body and a relatively thin susceptor layer can facilitate the production of an aerosol generating article that is simple, inexpensive and reliable.

The supporting main part can be made of a material that is not subject to induction heating. Advantageously, this can reduce heating of the pantograph surfaces that are not in contact with the aerosol-generating substrate, where the surfaces of the support body form pantograph surfaces that are not in contact with the aerosol-generating substrate.

The support body may contain electrical insulating material. As used herein, the term “electrical insulating” refers to materials having an electrical resistivity of at least 1 x 10 ⁴ ohm-meter (Ohm-m) at twenty degrees Celsius.

The support body may include thermal insulation material for thermally insulating the first pantograph from the second pantograph. As used herein, the term "thermal insulating material" is used to describe a material having a volumetric thermal conductivity of less than or equal to approximately 40 watts per meter-Kelvin (W/(mK)) at a temperature of 23 degrees Celsius and 50 percent relative humidity when measured using Modified Transient Planar Source (MTPS) method.

Forming the thermal insulating material support body can provide a thermal barrier between the current collector layer and other components of the induction heating arrangement, such as an inductor surrounding the induction heating element. This can reduce the heat transfer between the current collector and other components of the induction heating system, which is an advantage.

If the susceptor is a tubular susceptor having a cavity for accommodating an aerosol-forming substrate, the support body may be a tubular support body, and a susceptor layer may be formed on the inner surface of the support body. Providing a susceptor layer on the inner surface of the support body allows the susceptor layer to be positioned adjacent to the aerosol-forming substrate in the cavity of the induction heating element, improving heat transfer between the susceptor layer and the aerosol-forming substrate.

In some preferred embodiments, the first pantograph comprises a tubular support body formed from a thermal insulation material and a pantograph layer on an inner surface of the tubular support body. In some preferred embodiments, the second pantograph comprises a tubular support body formed from a thermal insulation material and a pantograph layer on an inner surface of the tubular support body.

The current collector may be provided with a protective outer layer, for example a protective ceramic layer or a protective glass layer. The protective outer layer can improve the strength of the pantograph and make the pantograph easier to clean. The protective outer layer may substantially surround the current collector. The current collector may contain a protective coating formed from glass, ceramics or inert metal.

The induction heating element contains an intermediate element located between the first pantograph and the second pantograph.

The intermediate element may have any suitable shape. The intermediate element may have any suitable cross-section. For example, the intermediate element may have a circular, elliptical, square, rectangular, triangular or other polygonal cross-section. The intermediate element may be tubular. The tubular intermediate element contains an annular body defining an internal cavity. The intermediate element may be configured to allow gas to penetrate from the outside of the intermediate element into the internal cavity. The cavity of the intermediate element can be configured to accommodate a part of the aerosol-generating product. The cavity of the intermediate element may be an open cavity. The spacer cavity may be open at one end. The cavity of the intermediate element can be open at both ends.

In some preferred embodiments, the first pantograph and the second pantograph are tubular pantographs and the intermediate member is a tubular intermediate member. In these embodiments, the tubular first pantograph, tubular second pantograph, and tubular intermediate member may be substantially aligned. The tubular first pantograph, the tubular intermediate member, and the tubular second pantograph may be arranged end to end in the shape of a tubular rod. The internal cavities of the tubular first pantograph, the tubular intermediate member, and the tubular second pantograph may be substantially aligned. The internal cavities of the tubular first pantograph, the tubular intermediate member, and the tubular second pantograph may define a cavity of the induction heating element.

The intermediate element may be formed from any suitable material.

In some embodiments, the intermediate element is formed from the same material as the first pantograph. In some embodiments, the intermediate element is formed from the same material as the second pantograph. In some embodiments, the first pantograph, the second pantograph, and the intermediate member are formed from the same material.

In some preferred embodiments, the intermediate element is formed from a material different from the material of the first pantograph and the second pantograph.

The intermediate element may include thermal insulating material for thermally insulating the first pantograph from the second pantograph.

The intermediate element may include electrically insulating material to electrically isolate the first pantograph from the second pantograph.

The intermediate element may comprise at least one of: thermal insulating material for thermally insulating the first pantograph from the second pantograph; and an electrical insulating material for electrically insulating the first pantograph from the second pantograph. In some preferred embodiments, the intermediate member comprises thermally insulating material for thermally insulating the first pantograph from the second pantograph and electrically insulating material for electrically insulating the first pantograph from the second pantograph.

Particularly preferred materials for the spacer may include polymeric materials such as polyetheretherketone (PEEK), liquid crystal polymers such as Kevlar®, certain types of cement, glass and ceramic materials such as zirconia (ZrO2), silicon nitride (Si3N4) and oxide aluminum (Al2O3).

The intermediate element is gas-permeable. In other words, the intermediate element is designed in such a way that it allows gas to penetrate through the intermediate element. Typically, the intermediate element is configured to allow gas to pass from one side of the intermediate element to the other side of the intermediate element. The intermediate element may comprise an outer side and an inner side opposite the outer side. The intermediate element may be configured to allow gas to penetrate from the outside to the inside.

In some embodiments, the intermediate member includes an air passage configured to allow air to pass through the intermediate member. In these embodiments, the intermediate element does not necessarily have to be made of a gas-permeable material. Accordingly, in some embodiments, the intermediate element is formed from a gas-impermeable material and includes an air passage configured to allow air to pass through the intermediate element. The intermediate element may include a plurality of air passages. The intermediate element may comprise any suitable number of air passages, for example two, three, four, five or six air passages. In the case where the intermediate element contains a plurality of air passages, the air passages may be evenly spaced from the intermediate element.

If the intermediate element is a tubular intermediate element defining an internal cavity, the intermediate element may include an air passage configured to allow air flow from the outer surface of the intermediate element into the internal cavity. The intermediate element may include an air passage extending from the outer surface to the inner surface. In case the tubular intermediate member contains multiple air passages, the air passages may be evenly spaced around the circumference of the tubular intermediate member.

In some embodiments, the intermediate element may comprise a porous material that is gas permeable. In these embodiments, the porosity of the material may provide gas permeability. In other words, the pores of the porous material may be of sufficient size and communicate with each other sufficiently to allow gas to pass through the porous material. Such porous materials may not require special air passages through the porous material in order for the porous material to be gas permeable. However, it is also contemplated that in some embodiments, the intermediate element may comprise a porous material containing at least one air passage.

The intermediate element may comprise a first porous material and a second porous material. The second porous material may have a higher porosity than the first porous material. In these embodiments, the increased porosity of the second porous material compared to the first porous material may promote air flow toward the second porous material.

The intermediate element may include a distal end adjacent the first pantograph and a proximal end opposite the distal end and adjacent the second pantograph. The first porous material may be located towards the distal end of the intermediate element. The second porous material may be positioned toward the proximal end of the intermediate member. Accordingly, the arrangement of the first porous material and the second porous material may facilitate the flow of air towards the proximal end of the intermediate element, towards the second porous material and the second current collector.

In some preferred embodiments, the porosity of the second porous material, measured by mercury porosimetry in accordance with ISO 15901-1:2005, is at least 1.5 times the porosity of the first porous material. More preferably, the porosity of the second porous material, as measured by mercury porosimetry, is at least twice the porosity of the first porous material.

In some preferred embodiments, the porosity of the second porous material, measured by mercury porosimetry in accordance with ISO 15901-1:2005, may be from about 20% to about 50%, and the porosity of the first porous material, measured by mercury porosimetry in accordance with ISO 15901 -1:2005 may range from about 5% to about 35%.

In some embodiments, the porosity of the second porous material, measured by mercury porosimetry in accordance with ISO 15901-1:2005, can be from about 1.5 times to about 10 times the porosity of the first porous material, preferably from about 1.5 times to approximately 5 times the porosity of the first porous material. In other embodiments, the porosity of the second porous material, measured by mercury porosimetry in accordance with ISO 15901-1:2005, can be from about 2 times to about 10 times the porosity of the first porous material, preferably from about 2 times to about 10 times. 5 times the porosity of the first porous material.

In some embodiments, the intermediate element comprises a third porous material. The third porous material may be located between the first porous material and the second porous material. The third porous material may have a higher porosity than the first porous material. The third porous material may have a lower porosity than the second porous material.

The induction heating element may be included in the induction heating arrangement.

The induction heating arrangement further includes a first inductor and a second inductor.

The first inductor is configured such that a varying electric current supplied to the first inductor generates a varying magnetic field. The first inductor is positioned relative to the induction heating element such that a varying electric current supplied to the first inductor generates a varying magnetic field that heats the first current collector of the induction heating element.

The second inductor is configured such that a varying electric current supplied to the second inductor generates a varying magnetic field. The second inductor coil is positioned relative to the induction heating element such that a varying electric current supplied to the second inductor coil generates a varying magnetic field that heats the second current collector of the induction heating element.

The inductor can be of any suitable shape. For example, the inductor may be a planar inductor. The planar inductor may be wound in a spiral pattern, essentially in a plane. Preferably, the inductor is a tubular inductor defining the internal cavity. Typically, a tubular inductor is wound helically around an axis. The induction coil can be oblong. In particular, preferably the inductor may be an elongated tubular inductor. The inductor can have any suitable cross-section. For example, the inductor may have a circular, elliptical, square, rectangular, triangular, or other polygonal cross-section.

The induction coil may be formed from any suitable material. The induction coil is formed from a conductive material. Preferably, the inductor is formed from a metal or a metal alloy.

In case the inductor is a tubular inductor, preferably, a portion of the induction heating element is located inside the inner cavity of the inductor. Particularly preferably, the first inductor is a tubular inductor, and at least part of the first current collector is located inside the inner cavity of the first inductor. The length of the tubular first inductor may be substantially close to the length of the first current collector. Particularly preferably, the second inductor is a tubular inductor, and at least a portion of the second current collector is located inside the inner cavity of the second inductor. The length of the tubular second inductor may be substantially close to the length of the second current collector.

In some embodiments, the second inductor is substantially identical to the first inductor. In other words, the first inductor and the second inductor have the same shape, size and number of turns. Particularly preferably, the second inductor is substantially identical to the first inductor in those embodiments where the second pantograph is substantially identical to the first pantograph.

In some embodiments, the second inductor is different from the first inductor. For example, the second inductor may have a different length, number of turns, or cross-section than the first inductor. Particularly preferably, the second inductor is different from the first inductor in those embodiments where the second pantograph is different from the first pantograph.

The first inductor and the second inductor may be arranged in any suitable arrangement. In particular, preferably the first inductor and the second inductor are coaxially aligned along the axis. In case the first inductor and the second inductor are elongated tubular inductors, the first inductor and the second inductor may be coaxially aligned along the longitudinal axis so that the internal cavities of the coils are aligned along the longitudinal axis.

The induction heating arrangement may contain any suitable number of inductors. An induction heating element contains several inductors. The induction heating arrangement contains at least two inductors. Preferably, the number of inductors of the induction heating arrangement is equal to the number of current collectors of the induction heating element. The number of inductors of the induction heating arrangement may differ from the number of current collectors of the induction heating element. In case the number of inductors is equal to the number of pantographs, preferably each inductor is placed around a pantograph. Particularly preferably, each inductor extends substantially along the length of the current collector around which it is placed.

The induction heating element may include a flux concentrator. A flux concentrator may be placed around the inductor of the induction heating arrangement. The flux concentrator is configured to deform the changing magnetic field generated by the inductor in the direction of the induction heating element.

By deforming the magnetic field in the direction of the induction heating element, the flux concentrator can concentrate the magnetic field on the induction heating element, which is advantageous. This may increase the efficiency of the induction heating arrangement compared to embodiments in which a flux concentrator is not provided. As used herein, the phrase “concentrate a magnetic field” means to deform a magnetic field such that the magnetic energy density of the magnetic field increases at the location where the magnetic field is “concentrated.”

As used herein, the term “flux concentrator” refers to a component having a high relative magnetic permeability that serves to concentrate and direct the magnetic field or magnetic field lines generated by the inductor. As used herein, the term "relative permeability" refers to the ratio of the magnetic permeability of a material or medium, such as a flux concentrator, to the magnetic permeability of free space, "µ ₀ ", where µ ₀ represents 4 π × 10 ⁻⁷ newtons per ampere squared (Н·A ⁻² ).

As used herein, the term “high relative magnetic permeability” refers to a relative magnetic permeability of at least 5 at 25 degrees Celsius, such as at least 10, at least 20, at least 30, at least 40, at at least 50, at least 60, at least 80 or at least 100 degrees Celsius. These exemplary values preferably refer to relative permeability values for a frequency of 6 to 8 MHz and a temperature of 25 degrees Celsius.

The flow concentrator may be made of any suitable material or combination of materials. Preferably, the flux concentrator comprises a ferromagnetic material, for example a ferrite material, ferrite powder held in a binder, or any other suitable material containing a ferrite material, such as ferritic iron, ferromagnetic steel or stainless steel.

In some embodiments, the induction heating arrangement includes a flux concentrator positioned around the first inductor and the second inductor. In these embodiments, the flux concentrator is configured to deform the varying magnetic field generated by the first inductor toward the first susceptor of the induction heating element and to deform the varying magnetic field generated by the second inductor toward the second susceptor of the induction heating element.

In some of these embodiments, a portion of the flux concentrator extends into an intermediate element between the first pantograph and the second pantograph. Passage of the flux concentrator portion into the intermediate element between the first pantograph and the second pantograph may further deform the magnetic field generated by the first inductor and the magnetic field generated by the second inductor. This additional deformation may result in an additional concentration of the magnetic field generated by the first inductor in the direction of the first pantograph and an additional concentration of the magnetic field generated by the second inductor in the direction of the second pantograph. This can further improve the efficiency of the induction heating arrangement.

In some embodiments, the induction heating arrangement includes multiple flux concentrators. In some preferred embodiments, a separate flux concentrator is placed around each inductor. Providing each inductor with a dedicated flux concentrator may allow the flux concentrator to be optimally configured to deform the magnetic field generated by the inductor. Such an arrangement can also provide the formation of an induction heating arrangement from modular induction heating assemblies. Each induction heating assembly may include an inductor and a flux concentrator. Providing modular induction heating assemblies can speed up the standardized production of induction heating assemblies and provide the ability to remove and replace individual assemblies.

In some preferred embodiments, the induction heating arrangement comprises: a first flux concentrator disposed around a first inductor, the first flux concentrator configured to deform a varying magnetic field generated by the first inductor toward the first susceptor; and a second flux concentrator disposed around the second inductor, the second flux concentrator configured to deform a changing magnetic field generated by the second inductor toward the second current collector.

In these preferred embodiments, a portion of the first flux concentrator may extend into an intermediate element between the first pantograph and the second pantograph. In these preferred embodiments, a portion of the second flux concentrator may extend into an intermediate element between the first pantograph and the second pantograph. The passage of a portion of the flux concentrator into the intermediate element between the pantographs may allow the flux concentrator to further deform the magnetic field generated by the inductor in the direction of the pantograph.

The induction heating arrangement may further comprise an induction heating arrangement housing. The housing can connect together the induction heating element, inductors and flux concentrators. This can help to consolidate the relative arrangements of the components of the induction heating arrangement and improve the interface between the components. Preferably, the casing of the induction heating arrangement is formed of an electrical insulating material.

In the case where the induction heating arrangement includes separate induction heating units comprising an inductor and a flux concentrator, each induction heating unit may include an induction heating unit housing. The induction heating unit casing can assemble the components of the induction heating unit and improve the interface between the components. Preferably, the casing of the induction heating unit is formed from an electrically insulating material.

The induction heating arrangement may be contained within an aerosol generating device.

The aerosol generating device may include a power source. The power source may be any suitable type of power supply. The power source may be a DC power supply. In some preferred embodiments, the power source is a battery, such as a rechargeable lithium-ion battery. The power source may be another type of charge storage device, such as a capacitor. The power supply may need to be recharged. The power source may have a capacity that allows sufficient energy to be stored for one or more uses of the device. For example, the power source may have sufficient capacity to provide continuous aerosol generation for a period of approximately six minutes, which corresponds to the typical time required to smoke a conventional cigarette, or for a period that is a multiple of six minutes. In another example, the power supply may have sufficient capacity to support a predetermined number of device uses or individual activations. In one embodiment, the power supply is a DC power supply having a DC voltage in the range of about 2.5 volts to about 4.5 volts and a DC current in the range of about 1 amp to about 10 amps (corresponding to the power supply wattage ranging from approximately 2.5 watts to approximately 45 watts).

The aerosol generating device may include a controller coupled to an induction heating arrangement and a power source. In particular, the aerosol generating device may include a controller coupled to a first inductor, a second inductor, and a power supply. The controller is configured to control the power supply to the induction heating assembly from a power source. The controller may include a microprocessor, which may be a programmable microprocessor, a microcontroller, or an application specific integrated circuit (ASIC) or other electronic circuit capable of providing control. The controller may contain additional electronic components. The controller may be configured to control the supply of current to the induction heating arrangement. Current may be supplied to the induction heating assembly continuously upon activation of the aerosol generating device, or may be supplied intermittently, such as from puff to puff.

The controller may advantageously comprise a DC/AC converter, which may comprise a Class C, Class D or Class E power amplifier.

The controller may be configured to supply varying current to the induction heating arrangement at any suitable frequency. The controller may be configured to supply varying current to the induction heating assembly at a frequency of from about 5 kilohertz to about 30 megahertz. In some preferred embodiments, the controller is configured to supply varying current to the induction heating assembly from about 5 kilohertz to about 500 kilohertz. In some embodiments, the controller is configured to supply high frequency varying current to the induction heating arrangement. As used herein, the term “high frequency varying current” refers to varying current with a frequency of about 500 kilohertz to about 30 megahertz. The high frequency varying current may have a frequency of from about 1 megahertz to about 30 megahertz, such as from about 1 megahertz to about 10 megahertz, or, for example, from about 5 megahertz to about 8 megahertz.

The aerosol generating device may include a device housing. The device casing may be oblong. The device housing may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics or composite materials containing one or more of such materials, or thermoplastic materials suitable for use in the food or pharmaceutical industries, for example polypropylene, polyetheretherketone (PEEK) and polyethylene. Preferably, the material is light and non-fragile.

The device housing may define a device cavity for housing the aerosol-forming substrate. The cavity of the device may be configured to accommodate at least a portion of the aerosol generating article. The cavity of the device can have any suitable shape and size. The cavity of the device may be substantially cylindrical. The device cavity may have a substantially circular cross-section.

An induction heating element may be placed in the cavity of the device. An induction heating element may be placed around the cavity of the device. If the induction heating element is a tubular induction heating element, the induction heating element may surround a cavity of the device. The inner surface of the induction heating element may form the inner surface of a cavity of the device.

The first inductor and the second inductor may be placed in the cavity of the device. The first inductor and the second inductor may be placed around the cavity of the device. The first inductor and the second inductor may surround the device cavity. The inner surface of the first inductor and the second inductor may define an inner surface of the device cavity.

The device may have a proximal end and a distal end opposite the proximal end. Preferably, the device cavity is located at the proximal end of the device.

The device housing may include an air inlet. The air inlet may be configured to draw ambient air into the device housing. The device housing may include any suitable number of air inlet openings. The device housing may include a plurality of air inlet openings.

The device housing may include an air outlet. The air outlet may be configured to allow air to enter the device cavity from within the device housing. The device housing may include any suitable number of air outlets. The device housing may include a plurality of air outlets.

The aerosol generating device may determine a path for air flow extending from the air inlet to the intermediate element of the induction heating element. Such an air flow path may allow air to be drawn through the aerosol generating device, through the air inlet, and into the device cavity through the intermediate member.

In some embodiments, a portion of the air flow path may be defined between the inductor and the device housing. A portion of the air flow path may be defined between the first inductor and the housing of the device. A portion of the air flow path may be defined between the second inductor and the housing of the device. Providing a path for air flow between the inductor and the device casing can help insulate the device casing from the heated current collector and from the inductor, which may also become hot during use. This may help maintain a comfortable temperature on the outer surface of the device casing for the user to touch during use.

In these embodiments, in which the flux concentrator is located around the inductor, a portion of the air flow path defined between the inductor and the device casing may be defined between the flux concentrator and the device casing. Likewise, in the case where an induction heating arrangement casing is provided, the air flow passage portion defined between the inductor and the device casing may be defined between the induction heating arrangement casing and the device casing.

In some embodiments, a portion of the air flow path is defined between the inductor and the induction heating element. A portion of the air flow path may be defined between the first inductor and the first pantograph. A portion of the air flow path may be defined between the second inductor and the second current collector. Providing a path for air flow between the inductor and the induction heating element can help isolate the inductor from the heated current collector. This can help reduce any increase in inductor resistance during use due to heating from the heated induction heating element, which is an advantage.

In some embodiments, the device cavity includes a proximal end and a distal end opposite the proximal end. In these embodiments, the device cavity may be open at the proximal end to accommodate the aerosol generating article. In these embodiments, the device cavity may be substantially closed at the distal end. The device housing may include an air outlet at a distal end of the device cavity. The aerosol generating device may further comprise an annular seal towards a proximal end of the device cavity. The ring seal may extend into the cavity of the device. The O-ring may provide a substantially airtight seal between the device housing and the outer surface of the aerosol generating article housed in the device cavity. This may reduce the amount of air drawn into the device cavity during use through any gaps between the outer surface of the aerosol generating article and the inner surface of the device cavity. This may increase the volume of air drawn into the aerosol generating article through the permeable intermediate members.

In some embodiments, the device housing includes a mouthpiece. The mouthpiece may include at least one air inlet and at least one air outlet. The mouthpiece may contain more than one air inlet. The one or more air inlets may reduce the temperature of the aerosol before delivery to the user and may reduce the concentration of the aerosol before delivery to the user.

In some embodiments, the mouthpiece is provided as part of the aerosol generating article. As used herein, the term “mouthpiece” refers to a portion of an aerosol generating system placed in the mouth of a user to directly inhale the aerosol generated by the aerosol generating system from an aerosol generating article housed in the aerosol generating device.

The aerosol generating device may include a temperature sensor. The temperature sensor may be configured to sense the temperature of the induction heating element. The aerosol generating device may include a first temperature sensor configured to detect the temperature of the first pantograph. The aerosol generating device may include a second temperature sensor configured to detect the temperature of the second pantograph.

The aerosol generating device may include a user interface for activating the device, such as a button to initiate heating of the aerosol generating article.

The aerosol generating device may include a display for indicating the status of the aerosol generating device or substrate.

The aerosol generating device may include a puff sensor to detect that the user is taking a puff from the aerosol generating system.

Preferably, the aerosol generating device is portable. The aerosol-generating device may be comparable in size to a traditional cigar or cigarette. The aerosol generating device may have an overall length of from about 30 millimeters to about 150 millimeters. The aerosol generating device may have an outer diameter of from about 5 millimeters to about 30 millimeters.

The aerosol generating device may form part of an aerosol generating system.

The aerosol generating system may further comprise an aerosol generating article. The aerosol generating article may comprise a first aerosol generating substrate; and a second aerosol-forming substrate. When an aerosol-generating article is placed in a device cavity, at least a portion of a first aerosol-generating substrate may be placed in a first portion of the device cavity, and at least a portion of a second aerosol-generating substrate may be placed in a second portion of the device cavity.

An induction heating element forming part of an arrangement for induction heating of an aerosol generating device is configured to heat the aerosol generating substrate.

The aerosol-forming substrate may contain nicotine. The nicotine-containing substrate forming the aerosol may be a matrix of nicotine salt.

The aerosol-forming substrate may be liquid. The aerosol-forming substrate may contain solid components and liquid components. Preferably, the aerosol-forming substrate is solid.

The aerosol-forming substrate may contain material of plant origin. The aerosol-forming substrate may contain tobacco. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavor compounds that are released from the aerosol-forming substrate when heated. The aerosol-forming substrate may contain non-tobacco material. The aerosol-forming substrate may contain homogenized material of plant origin. The aerosol-forming substrate may comprise homogenized tobacco material. Homogenized tobacco material can be formed by agglomeration of bulk tobacco. In a particularly preferred embodiment, the aerosol-forming substrate comprises an assembled corrugated sheet of homogenized tobacco material. As used herein, the term “corrugated sheet” means a sheet having a plurality of substantially parallel folds or corrugations.

The aerosol-forming substrate may contain at least one aerosol-forming substance. An aerosol forming agent is any suitable known compound or mixture of compounds which, when used, promotes the formation of a dense and stable aerosol and is substantially resistant to thermal decomposition at the operating temperature of the system. Suitable aerosol-forming agents are well known in the art and include, without limitation: polyhydric alcohols such as triethylene glycol, 1,3-butanediol and glycerol; polyhydric alcohol esters such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers may include polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1,3-butanediol. Preferably, the aerosol-forming agent is glycerol. If present, the homogenized tobacco material may have an aerosol forming agent content equal to or greater than 5 wt. % based on dry weight, for example, from about 5 percent to about 30 weight percent. % based on dry weight. The aerosol-forming substrate may contain other additives and ingredients such as flavoring agents.

The aerosol-generating substrate may be contained in the aerosol-generating article. An aerosol generating device comprising an induction heating assembly may be configured to accommodate at least a portion of the aerosol generating article. The aerosol generating article may have any suitable shape. The aerosol generating article may have a substantially cylindrical shape. The aerosol generating article may be substantially oblong. The aerosol generating article may have a length and a circumference substantially perpendicular to the length.

The aerosol-forming substrate may be provided in the form of an aerosol-generating segment containing the aerosol-forming substrate. The aerosol generating segment may contain multiple units of aerosol generating substrate. The aerosol generating segment may comprise a first aerosol generating substrate and a second aerosol generating substrate. In some embodiments, the second aerosol-forming substrate is substantially the same as the first aerosol-forming substrate. In some embodiments, the second aerosol-forming substrate is different from the first aerosol-forming substrate.

In case the aerosol generating segment contains multiple aerosol generating substrates, the number of aerosol generating substrates may be the same as the number of current collectors in the induction heating element. Likewise, the number of aerosol-forming substrates may be the same as the number of inductors in the induction heating arrangement.

The aerosol generating segment may have a substantially cylindrical shape. The aerosol generating segment may be substantially elongated. The aerosol generating segment may have a length and a circumference substantially perpendicular to the length.

In the case where the aerosol-generating segment contains multiple units of aerosol-forming substrate, the units of aerosol-forming substrate may be arranged end-to-end along the axis of the aerosol-generating segment. In some embodiments, the aerosol generating segment may comprise a partition between adjacent units of aerosol generating substrate.

In some preferred embodiments, the aerosol generating article may have an overall length of from about 30 millimeters to about 100 millimeters. In some embodiments, the aerosol generating article has an overall length of approximately 45 millimeters. The aerosol generating article may have an outer diameter of from about 5 millimeters to about 12 millimeters. In some embodiments, the aerosol generating article may have an outer diameter of approximately 7.2 millimeters.

The aerosol generating segment may have a length of from about 7 millimeters to about 15 millimeters. In some embodiments, the aerosol generating segment may be approximately 10 millimeters or 12 millimeters in length.

The aerosol generating segment preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating article. The outer diameter of the aerosol generating segment can be from about 5 millimeters to about 12 millimeters. In one embodiment, the aerosol generating segment may have an outer diameter of approximately 7.2 millimeters.

The aerosol generating article may include a filter plug. The filter plug may be located at the proximal end of the aerosol generating product. The filter plug may be a cellulose acetate filter plug. In some embodiments, the filter plug may have a length of from about 5 millimeters to about 10 millimeters. In some preferred embodiments, the filter plug may be approximately 7 millimeters in length.

The aerosol generating article may comprise an outer wrapper. The outer wrapper may be formed from paper. The outer wrap may be permeable to gas in the aerosol generating segment. In particular, in embodiments providing multiple aerosol-forming substrates, the outer wrap may include perforations or other air inlets at the interface between adjacent aerosol-forming substrates. In the event that a baffle is provided between adjacent units of aerosol-forming substrate, the outer wrap may include perforations or other air inlet openings on the baffle. This can directly provide the aerosol-forming substrate with air that is not drawn through another aerosol-forming substrate. This can increase the amount of air taken up by each aerosol-forming substrate. This can improve the aerosol generation characteristics of the aerosol-forming substrate.

The aerosol generating article may also include a barrier between the aerosol generating substrate and the filter plug. The septum may have a size of approximately 18 millimeters, but may have a size ranging from about 5 millimeters to about 25 millimeters.

It should also be understood that individual combinations of the various features described above may be implemented, provided and used independently.

Embodiments of the present invention will now be described solely by way of example with reference to the accompanying drawings, in which:

Figure 1 is a schematic illustration of an induction heating element according to one embodiment of the present invention placed between a pair of inductors;

FIG. 2 is an exploded perspective view of an induction heating element according to one embodiment of the present invention; FIG.

FIG. 3 is a perspective view of the induction heating element shown in FIG. 2;

FIG. 4 is a cross-sectional view of an aerosol generating system according to one embodiment of the present invention, wherein the aerosol generating system includes an aerosol generating article and an aerosol generating device having an induction heating arrangement; FIG.

FIG. 5 is a cross-sectional view of the proximal end of the aerosol generating device shown in FIG. 4, including paths for air flow through the device; FIG.

FIG. 6 is a cross-sectional view of the proximal end of the aerosol generating device shown in FIG. 5, with the aerosol generating article housed in the cavity of the device; FIG.

FIG. 7 is a cross-sectional view of a proximal end of an aerosol generating device according to the present invention, with the aerosol generating article housed in a cavity of the device; FIG.

FIG. 8 is an exploded perspective view of an intermediate element of an induction heating element according to one embodiment of the present invention; FIG. And

FIG. 9 is a cross-sectional view of an induction heating arrangement in accordance with one embodiment of the present invention including an induction heating element with an intermediate element according to FIG. 8.

FIG. 1 is a schematic diagram of an induction heating element 10 according to one embodiment of the present invention. The induction heating element 10 is an elongated tubular element with a circular cross section. The induction heating element 10 includes a first pantograph 12, a second pantograph 14, and an intermediate member 16 located between the first pantograph 12 and the second pantograph 14. Both the first pantograph 12 and the second pantograph 14 are elongated tubular members with a circular cross-section. The intermediate element 16 is a tubular element having a circular cross-section. The first pantograph 12, the second pantograph 14 and the intermediate element 16 are coaxially aligned end to end along the longitudinal axis AA.

The induction heating element 10 includes a cylindrical cavity 20, open at both ends, defined by the inner surface of the tubular element 10. The cavity 20 is configured to accommodate a portion of a cylindrical aerosol-generating article (not shown) containing an aerosol-generating substrate such that the outer surface of the article, generating the aerosol may be heated by the first susceptor and the second susceptor, thereby heating the aerosol-generating substrate.

The cavity 20 contains three parts: a first part 22 at the first end defined by the inner surface of the tubular first pantograph 12, a second part 24 at the second end opposite the first end defined by the inner surface of the tubular second pantograph 14, and an intermediate part 26 defined by the inner surface of the tubular intermediate element 16. The first pantograph 12 is configured to heat the first part of the aerosol-generating product located in the first part 22 of the cavity 20, and the second pantograph 14 is configured to heat the second part of the aerosol-generating product located in the second part 24 of the cavity 20.

The first inductor 32 is located around the first pantograph 12 and extends substantially along the length of the first pantograph 12. As such, the first pantograph 12 is surrounded by the first inductor 32 substantially along its length. When a varying electric current is applied to the first inductor 32, the first inductor 32 generates a varying magnetic field concentrated in the first portion 22 of the cavity 20. Such varying magnetic field generated by the first inductor 32 induces eddy currents in the first pantograph 12, causing the first pantograph to heat up. pantograph 12.

The second inductor 34 is located around the second pantograph 14 and extends substantially along the length of the second pantograph 14. As such, the second pantograph 14 is surrounded by the second inductor 34 substantially along its length. When a varying electric current is applied to the second inductor 34, the second inductor 34 generates a varying magnetic field concentrated in the second portion 24 of the cavity 20. Such varying magnetic field generated by the second inductor 34 induces eddy currents in the second pantograph 14, causing the second pantograph to heat up. pantograph 14.

The intermediate element 16 is not a current collector, since it is formed from electrical insulating and thermal insulating material. Accordingly, the intermediate element 16 is not inductively heated by the varying magnetic field generated by either the first inductor 32 or the second inductor 34. In addition, since the intermediate element is made of a heat-insulating material, the rate of heat transfer between the first pantograph 12 and the second pantograph 14 is reduced compared with an induction heating element in which the first pantograph and the second pantograph are placed adjacent to each other in direct thermal contact. As a result, the intermediate element 16 between the first pantograph 12 and the second pantograph 14 provides selective heating of the first part 22 of the cavity 20 by the first pantograph 12 with minimal heating of the second part 24 of the cavity 20 and provides selective heating of the second part 24 of the cavity 20 by the second pantograph 14 with minimal heating of the first part 22 cavities 20.

Because the intermediate member 16 is also gas-permeable and allows air to flow into the intermediate portion 26 of the cavity 20, the flow of air through the intermediate member 16 also cools the intermediate portion 26 of the cavity 20 and the ends of the first pantograph 12 and the second pantograph 14 adjacent to the intermediate member 16. Accordingly, While the first pantograph 12 is heating to generate an aerosol from the aerosol-forming substrate located in the first portion 22 of the cavity 20, the flow of air through the intermediate element 16 further insulates the second pantograph 14 and the second portion 24 of the cavity 20 from heating by the first pantograph 12. Likewise, during During the heating of the second pantograph 14 with the generation of an aerosol from the aerosol-forming substrate located in the second part 24 of the cavity 20, the air flow through the intermediate element 16 additionally isolates the first pantograph 12 and the first part 22 of the cavity 20 from heating by the second pantograph 14.

The first pantograph 12 and the second pantograph 14 can be heated simultaneously by simultaneously supplying a varying electric current to the first inductor 32 and the second inductor 34. Alternatively, the first pantograph 12 and the second pantograph 14 may be heated independently or alternately by applying a varying electric current to the first inductor 32 in the absence of current being supplied to the second inductor 34 and by subsequently applying a varying electric current to the second inductor 34 in the absence of current being supplied to the first one. inductance coil 32. It is also contemplated that a varying electric current may be supplied to the first inductor 32 and the second inductor 34 in sequence.

FIGS. 2-6 show schematic illustrations of an aerosol generating system according to one embodiment of the present invention. The aerosol generating system includes an aerosol generating device 100 and an aerosol generating article 200. The aerosol generating device 100 includes an induction heating arrangement 110 according to the present invention. The induction heating assembly 110 includes an induction heating element 120 according to the present invention.

2 and 3 show schematic diagrams of an induction heating element 120. The induction heating element 120 includes: a first pantograph 122, a second pantograph 124, a third pantograph 126, a first intermediate element 128, a second intermediate element 130, and an end element 132. The first intermediate element 128 is located between the first pantograph 122 and the second pantograph 124. The second intermediate element 130 is located between the second pantograph 124 and the third pantograph 126. The end element 132 is located at the distal end of the induction heating element 120, which is the end of the first pantograph 122 opposite the end adjacent to the first intermediate element 128.

In this embodiment, each of the first pantograph 122, the second pantograph 124, and the third pantograph 126 are the same. Each of the pantographs 122, 124, 126 is an elongated tubular pantograph defining an internal cavity. Each pantograph and its corresponding internal cavity are substantially cylindrical with a circular cross-section that is constant along the length of the pantograph. The internal cavity of the first pantograph 122 defines the first section 134. The internal cavity of the second pantograph 124 defines the second section 136. The internal cavity of the third pantograph defines the third section 138.

Likewise, the first intermediate element 128 and the second intermediate element 130 are identical. The intermediate elements 128, 130 are tubular, defining an internal cavity. Each intermediate element 128, 130 is substantially cylindrical with a circular cross-section that is constant along the length of the intermediate element. The outer diameter of the intermediate members 128, 130 is equal to the outer diameter of the pantographs 122, 124, 126, so that the outer surface of the intermediate members 128, 130 can be flush with the outer surface of the pantographs 122, 124, 126. The inner diameter of the intermediate members 128, 130 is also equal to the inner diameter diameter of pantographs 122, 124, 126 such that the inner surface of the intermediate members 128, 138 can be flush with the inner surface of pantographs 122, 124, 126.

The first pantograph 122, the first intermediate member 128, the second pantograph 124, the second intermediate member 130, and the third pantograph 126 are arranged end to end and coaxially aligned along the B-B axis. In this arrangement, the pantographs 122, 124, 126 and intermediate members 128, 130 form a tubular elongated cylindrical structure. In some embodiments, this structure may form an induction heating element in accordance with the present invention.

The end member 132 is also identical to the intermediate members 128, 130. The end member 132 is located at the distal end of the first pantograph 122 and extends through the tubular elongated cylindrical structure formed from the pantographs 122, 124, 126 and the intermediate members 128, 130 to form an induction heating element 120.

The elongated tubular induction heating element 120 includes an internal cavity 140. The induction heating element cavity 140 is defined by the internal cavities of the current collectors 122, 124, 126 and the internal cavities of the intermediate elements 128, 130 and the end element 132. The induction heating element cavity 140 is configured to accommodate a generating segment aerosol, aerosol generating article 200, as described in more detail below.

The intermediate members 128, 130 and the end member 132 are formed from an electrical and thermal insulating material, which in this embodiment is a ceramic material such as zirconium dioxide (ZrO2). Accordingly, the current collectors 122, 124, 126 are substantially electrically isolated and thermally insulated from each other. The material of the intermediate members 128, 130 and the end member is also substantially gas-tight. However, the intermediate members 128, 130 and the end member 132 are gas permeable. Each of the intermediate member 128, 130 and end member 130 includes a plurality of air passages in the form of elongated slits 142. The slits 142 extend from the outer surface to the inner surface and allow air to flow from the outer surface into the inner cavity.

4, 5 and 6 show schematic cross-sectional views of an aerosol generating device 100 and an aerosol generating article 200.

The aerosol generating device 100 includes a generally cylindrical device housing 102 with a shape and size similar to a traditional cigar. The device housing 102 defines a device cavity 104 at the proximal end. The device cavity 104 is substantially cylindrical, open at the proximal end and substantially closed at the distal end opposite the proximal end. The device cavity 104 is configured to accommodate the aerosol generating segment 210 of the aerosol generating article 200. Accordingly, the length and diameter of the device cavity 104 is substantially similar to the length and diameter of the aerosol generating segment 210 of the aerosol generating article 200.

The aerosol generating device 100 further includes a power source 106 in the form of a rechargeable nickel-cadmium battery, a controller 108 in the form of a printed circuit board containing a microprocessor, an electrical connector 109, and an induction heating arrangement 110. The power supply 106, controller 108, and induction heating assembly 110 are housed within the device housing 102. An arrangement 110 for induction heating of the aerosol generating device 100 is located at the proximal end of the device 100 and is generally located around the cavity 104 of the device. An electrical connector 109 is located at the distal end of the device housing 109, opposite the device cavity 104.

The controller 108 is configured to control the supply of power from the power supply 106 to the induction heating assembly 110. The controller 108 further includes a DC-AC converter including a Class D power amplifier, and is configured to supply varying current to the induction heating arrangement 110. The controller 108 is also configured to control the recharging of the power supply 106 from the electrical connector 109. In addition, the controller 108 includes a puff sensor (not shown) configured to detect that a user is taking a puff on the aerosol generating article housed in the device cavity 104.

The induction heating assembly 110 includes three induction heating units, including a first induction heating unit 112, a second induction heating unit 114, and a third induction heating unit 116. The first induction heating unit 112, the second induction heating unit 114, and the third induction heating unit 116 are substantially identical. .

The first induction heating assembly 112 includes a cylindrical tubular first inductor 150, a cylindrical tubular first flux concentrator 152 disposed around the first inductor 150, and a cylindrical tubular first induction assembly housing 154 disposed around the first flux concentrator 152.

The second induction heating assembly 114 includes a cylindrical tubular second inductor 160, a cylindrical tubular second flux concentrator 162 disposed around the second inductor 160, and a cylindrical tubular second induction assembly housing 164 disposed around the second flux concentrator 162.

The third induction heating assembly 116 includes a cylindrical tubular third inductor 170, a cylindrical tubular third flux concentrator 172 disposed around the third inductor 170, and a cylindrical tubular third induction assembly housing 174 disposed around the third flux concentrator 172.

Accordingly, each induction heating assembly 112, 114, 116 forms a substantially tubular assembly with a circular cross-section. In each induction heating assembly 112, 114, 116, a flux concentrator extends across the proximal and distal ends of the inductor such that the inductor is located within the annular cavity of the flux concentrator. Likewise, the housing of each induction heating assembly extends along the proximal and distal ends of the flux concentrator such that the flux concentrator and inductor are housed within the annular cavity of the induction heating assembly housing. This arrangement allows the flux concentrator to concentrate the magnetic field generated by the inductor into the internal cavity of the inductor. This arrangement also allows the induction housing to contain the flux concentrator and inductor within the induction housing.

The induction heating assembly 110 further includes an induction heating element 120. The induction heating element 120 is positioned around the inner surface of the device cavity 104. In this embodiment, the device housing 102 defines the inner surface of the device cavity 104. However, it is contemplated that in some embodiments, the interior surface of the device cavity is defined by the interior surface of the induction heating element 120.

Induction heating assemblies 112, 114, 116 are located around the induction heating element 120 such that the induction heating element 120 and induction heating assemblies 112, 114, 116 are concentrically located around the cavity 104 of the device. The first induction heating assembly 112 is located around the first susceptor 122 at the distal end of the device cavity 104. A second induction heating assembly 114 is located around a second susceptor 124 in the central portion of the device cavity 104. A third induction heating assembly 116 is located around a third susceptor 126 at the proximal end of the device cavity 104. It is contemplated that in some embodiments, flux concentrators may also extend into intermediate elements of the induction heating element to further deform the magnetic fields generated by the inductors towards the current collectors.

The first inductor 150 is connected to the controller 108 and the power supply 106, and the controller 108 is configured to supply a varying electrical current to the first inductor 150. When the varying electrical current is supplied to the first inductor 150, the first inductor 150 generates a varying magnetic field that heats the first pantograph 122 by induction.

The second inductor 160 is connected to the controller 108 and the power supply 106, and the controller 108 is configured to supply a varying electrical current to the second inductor 160. When the varying electrical current is supplied to the second inductor 160, the second inductor 160 generates a varying magnetic field that heats the second pantograph 124 by induction.

The first inductor 170 is connected to the controller 108 and the power supply 106, and the controller 108 is configured to supply a varying electrical current to the third inductor 170. When the varying electrical current is supplied to the third inductor 170, the third inductor 170 generates a varying magnetic field that heats the third pantograph 126 by induction.

The device housing 102 also defines an air inlet 180 in close proximity to the distal end of the device cavity 106. The air inlet 180 is configured to draw ambient air into the device housing 102. Air flow paths are defined through the device to allow air to be drawn from the air inlet 180 into the device cavity 104. A first air flow path 181 is between the air inlet 180 and the air outlet at the distal end of the device cavity 104. The second air flow path 182 is defined between the air inlet 180 and the slots 142 of the end element 132 of the induction heating element 120. The third air flow path 184 is defined between the air inlet 180 and the slots 142 of the first intermediate element 128 of the induction heating element 120, with herein, a third air flow passage extends between the first induction heating unit housing 154 and the device housing 202. A fourth air flow path 186 is formed between the air inlet 180 and the slots 142 of the second intermediate member 130, and the fourth air flow path 186 extends between the second induction heating assembly housing 174 and the device housing 102.

The aerosol generating article 200 is generally provided in the form of a cylindrical rod having a diameter similar to the inner diameter of the device cavity 104. The aerosol generating article 200 includes a cylindrical cellulose acetate filter plug 204 and a cylindrical aerosol generating segment 210 wrapped together with an outer cigarette paper wrapper 220.

The filter plug 204 is located at the proximal end of the aerosol generating article 200 and forms the mouthpiece of the aerosol generating system upon which the user takes a puff to receive the aerosol generated by the system.

The aerosol generating segment 210 is located at the distal end of the aerosol generating article 200 and has a length substantially equal to the length of the device cavity 104. The aerosol generating segment 210 contains multiple aerosol generating substrates, including: a first aerosol generating substrate 212 at the distal end of the aerosol generating article 200, a second aerosol generating substrate 214 adjacent the first aerosol generating substrate 212, and a third substrate 216, which forms an aerosol, at the proximal end of the segment 210, which generates an aerosol, adjacent to the second substrate 216, which forms an aerosol. It should be understood that in some embodiments, two or more aerosol-forming substrate units may be formed from the same materials. However, in this embodiment, each of the aerosol-forming substrates 212, 214, 216 is different. The first aerosol-forming substrate 212 comprises a collected and corrugated sheet of homogenized tobacco material, without additional flavoring agents. The second aerosol-forming substrate 214 comprises an assembled and corrugated sheet of homogenized tobacco material containing a flavoring agent in the form of menthol. The third aerosol-forming substrate contains a flavoring agent in the form of menthol and does not contain tobacco material or any other source of nicotine. Each of the aerosol-forming substrates 212, 214, 216 also contains additional components, for example, one or more aerosol-forming agents and water, such that heating the aerosol-forming substrate generates an aerosol with the desired organoleptic properties.

The proximal end of the first aerosol-generating substrate 212 is exposed because it is not covered by the outer wrap 220. The outer wrap 220 includes a first line of perforations 222 surrounding the aerosol-generating article 200 at the interface between the first aerosol-generating substrate 212 and the second substrate. 224, forming an aerosol. The outer wrap 220 also includes a second line of perforations 224 surrounding the aerosol generating article 200 at the interface between the second aerosol generating substrate 214 and the third aerosol generating substrate 226. Perforations 222, 224 allow air to be drawn into the aerosol generating segment 210.

In this embodiment, the first aerosol-forming substrate 212, the second aerosol-forming substrate 214, and the third aerosol-forming substrate 216 are arranged end to end. However, it is contemplated that in other embodiments, a gap may be provided between the first aerosol-forming substrate and the second aerosol-forming substrate, and a gap may be provided between the second aerosol-forming substrate and the third aerosol-forming substrate.

As shown in FIG. 6, the length of the first aerosol-forming substrate 212 is such that the first aerosol-forming substrate 212 extends from the distal end of the device cavity 104, through the first region 134 of the first pantograph 122, and to the slots 142 of the first intermediate member 128. The length of the second aerosol-forming substrate 214 is such that the second aerosol-forming substrate 214 extends from the slots 142 of the first intermediate member 128 through the second region 136 of the second pantograph 124 and to the slots 142 of the second intermediate member 130. Length of the third aerosol-forming substrate 216 , is such that the third aerosol-forming substrate 216 extends from the slots 142 of the second intermediate member 130 to the proximal end of the device cavity 104.

In use, when the aerosol generating article 200 is placed in the device cavity 104, the user can puff on the proximal end of the aerosol generating article 200 to inhale the aerosol generated by the aerosol generating system. When a user puffs at the proximal end of the aerosol generating article 200, air is drawn into the device housing 102 at the air inlet 180 and is drawn along paths 181, 182, 184, 186 into the aerosol generating segment 210 of the aerosol generating article 200. Air is drawn into the proximal end of the first aerosol-forming substrate 212 through slots 142 in end member 132 and an outlet at the distal end of device cavity 104. Air is drawn into the proximal end of the second aerosol-forming substrate 214 through slits 142 in the first intermediate member 128 and first perforations 218 in the outer wrap 202 of the article 200. Air is drawn into the proximal end of the third aerosol-forming substrate 216 through slits 142 in the second intermediate member element 130 and second perforations 220 in the outer wrap 202 of the article 200. Thus, each of the aerosol-forming substrates 212, 214, 216 directly receives ambient air.

In this embodiment, the controller 108 of the aerosol generating device 100 is configured to supply power to the inductors of the induction heating arrangement 110 in a predetermined sequence. The predetermined sequence involves applying a varying electrical current to the first inductor 150 during the first puff from the user, then applying a varying electrical current to the second inductor 160 during the second puff from the user after the first puff has been completed, and then applying a varying electrical current to the first inductor 150. current to the third inductor 170 during the third puff from the user after the second puff has been completed. On the fourth puff, the sequence begins again at the first inductor 150. This sequence results in heating of the first aerosol-forming substrate 212 on the first puff, heating of the second aerosol-forming substrate 214 on the second puff, and heating of the third aerosol-forming substrate 216 on the third puff. Since the aerosol generating substrates 212, 214, 216 of the article 100 are all different, this sequence results in a different user experience with each puff of the aerosol generating system.

It should be understood that the controller 108 may be configured to energize the inductors in different sequences or simultaneously, depending on the desired delivery of the aerosol to the user. In some embodiments, the user may be able to control the aerosol generating device to change the sequence.

FIG. 7 shows a schematic cross-section of an aerosol generating system substantially similar to the aerosol generating system shown in FIGS. 2-6, with like reference numerals referring to like features. In the embodiment shown in FIG. 7, air flow paths are provided in the aerosol generating device 100 between the inductors and current collectors rather than between the induction heating elements and the device casing. The arrows shown in Figure 7 illustrate the paths for air flow through the system.

FIGS. 8 and 9 show schematic diagrams of an intermediate member 300 in accordance with another embodiment of the present invention. In this embodiment, the intermediate elements between adjacent current collectors of the induction heating element and any end elements provided comprise porous material. The porous material is gas permeable and accordingly the intermediate member 300 does not require the presence of air passages such as the slots 142 of the intermediate members 128, 130 described above.

Specifically, the intermediate member 300 includes three porous materials: a first porous material 302, a second porous material 304, and a third porous material 306. Each of the first porous material 302, the second porous material 304, and the third porous material 306 has a different porosity, which results in different gas permeability. for each of the materials. The difference in porosity and gas permeability of the porous materials allows the intermediate member 300 to be configured to promote air flow in a particular direction, as shown in FIG. 9.

The first porous material 302, the second porous material 304, and the third porous material 306 are each formed from a tubular porous material portion defining an internal cavity. The outer diameter and inner diameter of the porous materials 302, 304, 306 are substantially identical such that the porous materials 302, 304, 306 can be joined to form a tubular intermediate member having a substantially constant outer diameter and inner diameter, as shown in FIG. 8. The first porous material 302 and the third porous material 306 have substantially the same thickness and are relatively thin compared to the thickness of the second porous material 304.

Specifically, in this embodiment, the second porous material 304 is located above the first porous material 302, and the third porous material 306 is located above the second porous material 304. The second porous material 304 has a higher porosity than the first porous material 302 and the third porous material 306 has a higher porosity than the second porous material 304.

FIG. 9 shows an intermediate member 300 located between the first pantograph 122 and the second pantograph 124 according to the embodiment shown in FIGS. 2-6. The intermediate member 300 is positioned such that the first porous material 302 is disposed adjacent the first pantograph 122 and the third porous material 306 is disposed adjacent the second pantograph 124. Thus, the porosity of the intermediate member 300 increases toward the proximal end, away from the first pantograph 122. second pantograph 124. This may cause air to flow toward the proximal end toward the interior of the second pantograph 124 as shown in FIG. 9 rather than toward the interior of the first pantograph 122, which is advantageous.

It should be understood that the embodiments described above are specific examples only, and other embodiments are contemplated in accordance with the present invention.

Claims (46)

1. An induction heating element for an aerosol generating system, comprising: a cavity for housing an aerosol-forming substrate to be heated by an induction heating element; first pantograph; second pantograph; And an intermediate element located between the first pantograph and the second pantograph, wherein the intermediate element is gas-permeable, wherein the intermediate element comprises at least one of: heat-insulating material for thermally insulating the first pantograph from the second pantograph; And electrical insulating material for electrically isolating the first pantograph from the second pantograph. 2. Induction heating element according to claim 1, in which: the first pantograph is a tubular pantograph defining a cavity portion of the induction heating element; the second pantograph is a tubular pantograph defining a cavity portion of the induction heating element; And The intermediate element is a tubular intermediate element defining a portion of the cavity of the induction heating element. 3. The induction heating element of claim 1 or 2, wherein the induction heating element comprises an outer side and an inner side opposite the outer side, wherein the inner side at least partially defines a cavity for housing the aerosol-forming substrate, and wherein the intermediate element comprises one or more air passages configured to allow air to flow from the outside to the inside. 4. An induction heating element according to any one of claims 1 to 3, wherein the intermediate element comprises a porous material. 5. The induction heating element of claim 4, wherein the intermediate element comprises a first porous material and a second porous material, wherein the second porous material has a higher porosity than the first porous material. 6. The induction heating element of claim 5, wherein the intermediate element comprises a distal end adjacent the first pantograph and a proximal end opposite the distal end and adjacent the second pantograph, and wherein the first porous material is disposed toward the distal end of the intermediate member, and the second porous material is located towards the proximal end of the intermediate element. 7. The induction heating element of claim 5 or 6, wherein the intermediate element comprises a third porous material disposed between the first and second porous materials, wherein the third porous material has a higher porosity than the first porous material, and the third porous material has more lower porosity than the second porous material. 8. An induction heating arrangement comprising: induction heating element according to any one of claims 1 to 7; a first inductor; And the second inductor, and: the first inductor coil is positioned relative to the induction heating element such that a varying electric current supplied to the first inductor coil generates a varying magnetic field that heats the first current collector of the induction heating element; And the second inductor is positioned relative to the induction heating element such that a varying electric current supplied to the second inductor generates a varying magnetic field that heats the second current collector of the induction heating element. 9. Arrangement for induction heating according to claim 8, in which: the first inductor is a tubular coil having an internal cavity, wherein the first current collector is located in the internal cavity of the first inductor; And the second inductor is a tubular coil having an internal cavity, wherein the second current collector is located in the internal cavity of the second inductor. 10. An aerosol generating device comprising an induction heating arrangement according to claim 8 or 9. 11. An aerosol generating device containing: a device housing defining a device cavity for housing the aerosol-forming substrate; an induction heating assembly comprising: - an induction heating element containing: -- a cavity for placing a substrate that forms an aerosol to be heated by an induction heating element; -- a first current collector located around the first part of the device cavity; -- a second current collector located around the second part of the device cavity; And -- an intermediate element located around the intermediate part of the device cavity, between the first part and the second part of the device cavity, wherein the intermediate element is gas-permeable, wherein the intermediate element contains at least one of: --- thermal insulation material for thermal insulation of the first pantograph from the second pantograph; And --- electrical insulating material for electrically isolating the first pantograph from the second pantograph; - a first inductor located around at least a part of the first pantograph and a first part of the device cavity; And - a second inductor located around at least a part of the second pantograph and a second part of the device cavity; and a power supply coupled to the induction heating arrangement and configured to supply a varying electric current to the first inductor and the second inductor, wherein: when a varying electric current is supplied to the first inductor, the first inductor generates a varying magnetic field that heats the first susceptor; And when a varying electric current is applied to the second inductor, the second inductor generates a varying magnetic field that heats the second current collector. 12. The aerosol generating device according to claim 11, wherein the device housing further comprises an air inlet hole, and wherein the aerosol generating device defines an air flow path extending from the air inlet hole to the intermediate element of the induction heating element, with the ability to draw air through the aerosol generating device from the air inlet and into the cavity of the device through the intermediate element. 13. The aerosol generating device according to claim 12, wherein a portion of the air flow path is defined between the first inductor and the device casing, and a portion of the air flow path is defined between the second inductor and the device casing. 14. The aerosol generating device according to claim 12 or 13, wherein a portion of the air flow path is defined between the first inductor and the first susceptor, and a portion of the air flow path is defined between the second inductor and the second susceptor.