Inductive heating arrangement with segmented inductive heating element

Abstract

To provide an inductive heating element for an aerosol-generating system, an inductive heating arrangement for an aerosol-generating system, an aerosol-generating device with an inductive heating arrangement, and an aerosol-generating system with an aerosol-generating device having an inductive heating arrangement.SOLUTION: An inductive heating element (10) comprises: a first susceptor (12), the first susceptor being a tubular susceptor defining an inner cavity for receiving aerosol-forming substrate; a second susceptor (14), the second susceptor being a tubular susceptor defining an inner cavity for receiving aerosol-forming substrate; and a separation (15) between the first susceptor and the second susceptor, the separation thermally insulating the first susceptor from the second susceptor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an induction heating element for an aerosol generation system, an induction heating arrangement for an aerosol generation system, an aerosol generation device having the induction heating arrangement, and an aerosol generation system having the aerosol generation device having the induction heating arrangement.

Background Art

[0002] Numerous electrically operated aerosol generation systems have been proposed in the art that use an aerosol generation device having an electric heater to heat an aerosol-forming substrate such as a tobacco plug. One objective of such aerosol generation systems is to reduce well-known harmful smoke components of the type produced by the combustion and pyrolysis of tobacco in conventional cigarettes. Typically, the aerosol generation substrate is provided as part of an aerosol-generating article that is inserted into the cavity of the aerosol generation device. In some well-known systems, a resistive heating element such as a heating blade is inserted into or around the aerosol-forming substrate when the article is received within the aerosol generation device to heat the aerosol-forming substrate to a temperature at which volatile constituents capable of forming an aerosol can be released. In other aerosol generation systems, an induction heater rather than a resistive heating element is used. An induction heater typically comprises an inductor coil forming part of the aerosol generation device and a susceptor arranged in thermal proximity to the aerosol-forming substrate. The inductor generates a varying magnetic field that induces eddy currents and hysteresis losses in the susceptor, heating the susceptor and thereby heating the aerosol-forming substrate. Induction heating enables the generation of an aerosol without exposing the heater to the aerosol-generating article. This can improve the ease of cleaning of the heater.

[0003] Some well-known aerosol generating devices include two or more induction coils, and each induction coil is arranged to heat different parts of the susceptor. Such aerosol generating devices may be used to heat different parts of the aerosol generating article at different times or at different temperatures. However, for such aerosol generating devices, it may be difficult to heat one part of the aerosol generating article without indirectly heating adjacent parts of the aerosol generating article.

Summary of the Invention

Problems to be Solved by the Invention

[0004] It would be desirable to provide an aerosol generating device that reduces or overcomes these problems associated with well-known systems.

Means for Solving the Problems

[0005] According to the present disclosure, an induction heating element for an aerosol generating system is provided. The induction heating element may include a first susceptor. The first susceptor may be a tubular susceptor defining an inner cavity for receiving an aerosol forming substrate. The induction heating element may include a second susceptor. The second susceptor may be a tubular susceptor defining an inner cavity for receiving an aerosol forming substrate. The induction heating element may further include a separation portion between the first susceptor and the second susceptor. The separation portion may thermally insulate the first susceptor from the second susceptor.

[0006] According to the present disclosure, an induction heating element for an aerosol generating system is provided, the induction heating element including a first susceptor that is a tubular susceptor defining an inner cavity for receiving an aerosol forming substrate, a second susceptor that is a tubular susceptor defining an inner cavity for receiving an aerosol forming substrate, and a separation portion between the first susceptor and the second susceptor that thermally insulates the first susceptor from the second susceptor.

[0007] Providing an induction heating element having a separation portion between a first susceptor and a second susceptor may reduce heat transfer through conduction between the first susceptor and the second susceptor as compared to an induction heating element comprising a single susceptor of the same length. This may improve the ability of the induction heating element to selectively heat individual portions of the aerosol-forming substrate.

[0008] According to the present disclosure, an induction heating arrangement for an aerosol generation system is provided.

[0009] The induction heating arrangement may comprise an induction heating element. The induction heating element may comprise a first susceptor. The first susceptor may be a tubular susceptor defining an inner cavity for receiving an aerosol-forming substrate. The induction heating element may comprise a second susceptor. The second susceptor may be a tubular susceptor defining an inner cavity for receiving an aerosol-forming substrate. The induction heating element may further comprise a separation portion between the first susceptor and the second susceptor. The separation portion may thermally insulate the first susceptor from the second susceptor.

[0010] The induction heating arrangement may further comprise a first inductor coil. The induction heating arrangement may further comprise a second inductor coil. The first inductor coil may be arranged relative to the induction heating element such that a changing current supplied to the first inductor coil generates a varying magnetic field that heats the first susceptor of the induction heating element. The second inductor coil may be arranged relative to the induction heating element such that a changing current supplied to the second inductor coil generates a varying magnetic field that heats the second susceptor of the induction heating element.

[0011] In particular, according to the present disclosure, an induction heating arrangement for an aerosol generation system is provided, the induction heating arrangement including an induction heating element, a first induction coil, and a second induction coil. The induction heating element includes a first susceptor, which is a tubular susceptor defining an inner cavity for receiving an aerosol-forming substrate, a second susceptor, which is a tubular susceptor defining an inner cavity for receiving an aerosol-forming substrate, and a separation portion between the first susceptor and the second susceptor, the separation portion thermally insulating the first susceptor from the second susceptor. The first induction coil is arranged relative to the induction heating element such that a changing current supplied to the first induction coil generates a varying magnetic field that heats the first susceptor of the induction heating element. The second induction coil is arranged relative to the induction heating element such that a changing current supplied to the second induction coil generates a varying magnetic field that heats the second susceptor of the induction heating element.

[0012] Providing an induction heating arrangement having a first induction coil arranged to heat the first susceptor of the induction heating element and a second induction coil arranged to heat the second susceptor of the induction heating element enables selective heating of the first susceptor and the second susceptor. Such selective heating can enable the induction heating arrangement to heat different portions of the aerosol-forming substrate at different times and may enable one of the susceptors to be heated to a different temperature than the other susceptor.

[0013] According to the present disclosure, an aerosol generation device comprising an induction heating arrangement is provided.

[0014] The induction heating arrangement may comprise an induction heating element. The induction heating element may comprise a first susceptor. The first susceptor may be a tubular susceptor defining an inner cavity for receiving an aerosol-forming substrate. The induction heating element may comprise a second susceptor. The second susceptor may be a tubular susceptor defining an inner cavity for receiving an aerosol-forming substrate. The induction heating element may further comprise a separation part between the first susceptor and the second susceptor. The separation part may thermally insulate the first susceptor from the second susceptor.

[0015] The induction heating arrangement may further comprise a first inductor coil. The induction heating arrangement may further comprise a second inductor coil. The first inductor coil may be arranged relative to the induction heating element such that a changing current supplied to the first inductor coil generates a varying magnetic field that heats the first susceptor of the induction heating element. The second inductor coil may be arranged relative to the induction heating element such that a changing current supplied to the second inductor coil generates a varying magnetic field that heats the second susceptor of the induction heating element.

[0016] In particular, according to the present disclosure, there is provided an aerosol generating device comprising a device housing defining a device cavity for receiving an aerosol-forming substrate. The aerosol generating device further comprises an induction heating arrangement including an induction heating element, a first inductor coil, and a second inductor coil. The induction heating element comprises a first susceptor disposed around a first portion of the device cavity, a second susceptor disposed around a second portion of the device cavity, and a separation portion between the first susceptor and the second susceptor, the separation portion thermally insulating the first susceptor from the second susceptor. The aerosol generating device further comprises a first inductor coil disposed around at least a portion of the first susceptor and around the first portion of the device cavity, a second inductor coil disposed around at least a portion of the second susceptor and around the second portion of the device cavity, and a power supply connected to the induction heating arrangement and configured to provide a changing current to the first inductor coil and the second inductor coil. When the changing current is supplied to the first inductor coil, the first inductor coil generates a varying magnetic field, which heats the first susceptor. When the changing current is supplied to the second inductor coil, the second inductor coil generates a varying magnetic field, which heats the second susceptor.

[0017] Providing an aerosol generating device having an induction heating arrangement having a first susceptor disposed around a first portion of the device cavity and a second susceptor disposed around a second portion of the device cavity may allow selectively heating the first portion of the device cavity by the first susceptor and the second portion of the device cavity by the second susceptor. Providing a first inductor coil arranged to heat the first susceptor and a second inductor coil arranged to heat the second susceptor may allow selectively heating the first susceptor and the second susceptor. Such selective heating allows the induction heating arrangement to heat different portions of the aerosol-forming substrate received within the device cavity to different temperatures at different times. This advantageously may allow the aerosol generating device to generate aerosols having different characteristics and increase the functionality and flexibility of the aerosol generating device.

[0018] According to the present disclosure, an aerosol generation system is provided. The aerosol generation system further includes an aerosol generating article including an aerosol forming substrate, and an aerosol generating device configured to receive at least a portion of the aerosol generating article. The aerosol generating article may include a first aerosol forming substrate and a second aerosol forming substrate. The aerosol generating device may include an induction heating arrangement. The induction heating arrangement may include an induction heating element. The induction heating element may include a first susceptor. The first susceptor may be a tubular susceptor defining an inner cavity for receiving the aerosol forming substrate. The induction heating element may include a second susceptor. The second susceptor may be a tubular susceptor defining an inner cavity for receiving the aerosol forming substrate. The induction heating element may further include a separation portion between the first susceptor and the second susceptor. The separation portion may thermally insulate the first susceptor from the second susceptor. The induction heating arrangement may further include a first inductor coil. The induction heating arrangement may further include a second inductor coil. The first inductor coil may be arranged relative to the induction heating element such that a changing current supplied to the first inductor coil generates a varying magnetic field that heats the first susceptor of the induction heating element. The second inductor coil may be arranged relative to the induction heating element such that a changing current supplied to the second inductor coil generates a varying magnetic field that heats the second susceptor of the induction heating element. The induction heating arrangement may be arranged such that the first susceptor is positioned to heat the first aerosol forming substrate of the aerosol generating article when the aerosol generating article is received within the aerosol generating device. The induction heating arrangement may be arranged such that the second susceptor is positioned to heat the second aerosol forming substrate of the aerosol generating article when the aerosol generating article is received within the aerosol generating device.

[0019] Advantageously, such an aerosol generation system may be configured to selectively heat a first aerosol-forming substrate and a second aerosol-forming substrate of an aerosol-generating article. The second aerosol-forming substrate may be heated at a different time than the first aerosol-forming substrate. The second aerosol-forming substrate may be heated to a different temperature than the first aerosol-forming substrate. This may enable the aerosol generation system to generate an aerosol having particularly desirable characteristics and may also enable the aerosol generation system to generate aerosols having different characteristics.

[0020] As used herein, the term "aerosol-forming substrate" relates to a substrate having the ability to release a volatile compound capable of forming an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. An aerosol-forming substrate is typically part of an aerosol-generating article.

[0021] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate having the ability to release a volatile compound capable of forming an aerosol. For example, the aerosol-generating article may be an article that generates an aerosol that can be directly inhaled by a user who inhales or smokes on a mouthpiece at the proximal end or user side of the system. The aerosol-generating article may be disposable. An article comprising an aerosol-forming substrate comprising tobacco may be referred to herein as a tobacco stick.

[0022] As used herein, the term "aerosol generation device" refers to a device that interacts with an aerosol-forming substrate to generate an aerosol.

[0023] As used herein, the term "aerosol generation system" refers to a combination of an aerosol generation device and an aerosol-generating article. In an aerosol generation system, the aerosol-generating article and the aerosol generation device cooperate to generate an inhalable aerosol.

[0024] As used herein, the term "changing current" includes any current that changes over time to generate a varying magnetic field. The term "changing current" is intended to include alternating current. When the changing current is an alternating current, the alternating current generates an alternating magnetic field.

[0025] As used herein, the term "length" refers to the major dimension in the longitudinal direction of the aerosol generating device or aerosol generating article, or the major dimension in the longitudinal direction of a component of the aerosol generating device or aerosol generating article.

[0026] As used herein, the term "width" refers to the major dimension in the transverse direction at a particular location along the length of the aerosol generating device or aerosol generating article, or the major dimension in the transverse direction at a particular location along the length of a component of the aerosol generating device or aerosol generating article. The term "thickness" refers to the dimension in the transverse direction perpendicular to the width.

[0027] As used herein, the term "cross-sectional plane" is used to describe the cross-section of the aerosol generating device or aerosol generating article in a direction perpendicular to the longitudinal axis at a particular location along the length of the aerosol generating device or aerosol generating article, or the cross-section of a component of the aerosol generating device or aerosol generating article in a direction perpendicular to the longitudinal axis at a particular location along the length of the aerosol generating device or aerosol generating article.

[0028] As used herein, the term "proximal" refers to the user end or mouth-side end of the aerosol generating device or aerosol generating article. The proximal end of a component of the aerosol generating device or aerosol generating article is the end of the component closest to the user end, or the mouth-side end of the aerosol generating device or aerosol generating article. As used herein, the term "distal" refers to the end opposite the proximal end.

[0029] According to the present disclosure, an inductive heating element for an aerosol generating system is provided.

[0030] The heating element may be an externally inductive 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.

[0031] The external heating element is preferably configured to at least partially surround the aerosol-forming substrate when the aerosol-forming substrate is received by the aerosol-generating device. The inductive heating element may be configured to heat the outer surface of the aerosol-forming substrate when the aerosol-forming substrate is received within the inductive heating element cavity.

[0032] The inductive heating element comprises a cavity for receiving the aerosol-forming substrate. The inductive heating element may comprise an outer side and an inner side opposite the outer side. The inner side may at least partially define an inductive heating element cavity for receiving the aerosol-forming substrate. The first susceptor is a tubular susceptor that defines a portion of the inductive heating element cavity. The second susceptor is a tubular susceptor that defines a portion of the inductive heating element cavity.

[0033] In some embodiments, the inductive heating element comprises a plurality of inner cavities for receiving the aerosol-forming substrate. The inner cavity of the first susceptor may form a first cavity of the inductive heating element, and the inner cavity of the second susceptor may form a second cavity of the inductive heating element.

[0034] In some preferred embodiments, the inductive heating element comprises a single inner cavity for receiving the aerosol-forming substrate. In these embodiments, the inner cavity of the first susceptor defines a portion of the single inner cavity of the inductive heating element, and the inner cavity of the second susceptor defines a second portion of the single inner cavity of the inductive heating element. In some preferred embodiments, the inductive heating element is a tubular inductive heating element. The inner surface of the tubular inductive heating element may define the inductive heating element cavity.

[0035] In an embodiment where the aerosol generating device comprises a device cavity for receiving an aerosol forming substrate, the induction heating element may at least partially surround the device cavity. The induction heating element cavity may be aligned with the device cavity.

[0036] The induction heating element comprises a first susceptor and a second susceptor.

[0037] As used herein, the term "susceptor" refers to an element that includes a material having the ability to convert electromagnetic energy into heat. When the susceptor is positioned within a varying magnetic field, the susceptor is heated. The heating of the susceptor may be the result of at least one of hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0038] The susceptor may comprise any suitable material. The susceptor may be formed from any material that can be inductively heated to a temperature sufficient to aerosolize the aerosol forming substrate. Preferred susceptors may be heated to a temperature in excess of about 250 degrees Celsius. Preferred susceptors may be formed from a conductive material. As used herein, "conductive" refers to a material having an electrical resistivity of 1 × 10 -4 Ohm - meters (Ω·m) or less at 20 degrees Celsius. Preferred susceptors may be formed from a thermally conductive material. As used herein, the term "thermally conductive material" is used to describe a material having a thermal conductivity of at least about 10 watts per meter per kelvin (W / (m·K)) at 23 degrees Celsius and 50 percent relative humidity when measured using the modified transient plane source (MTPS) method.

[0039] Suitable materials for the susceptor include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composite materials of metallic materials. Some preferred susceptors contain metal or carbon. Some preferred susceptors contain ferromagnetic alloys such as, for example, ferromagnetic iron, ferromagnetic steel or stainless steel, ferromagnetic particles, and ferromagnetic materials such as ferrite. Some preferred susceptors are made of ferromagnetic materials. Suitable susceptors may contain aluminum. Suitable susceptors may be made of aluminum. The susceptor may contain at least about 5 percent, at least about 20 percent, at least about 50 percent, or at least about 90 percent of ferromagnetic or paramagnetic materials.

[0040] The susceptor is preferably formed of a material that is substantially impermeable to gases. In other words, the susceptor is preferably formed of a material that is not gas permeable.

[0041] The first susceptor is a tubular susceptor. The second susceptor is a tubular susceptor. The tubular susceptor comprises an annular body defining an inner cavity. The susceptor cavity is configured to receive an aerosol-forming substrate. The susceptor cavity may be an open cavity. The susceptor cavity may be open at one end. The susceptor cavity may be open at both ends.

[0042] When the susceptor is a tubular susceptor having a cavity for receiving an aerosol-forming substrate that is open at one or both ends, the susceptor is preferably substantially impermeable to gases from the outer surface to the inner surface defining the inner cavity. In other words, the susceptor is preferably substantially impermeable to gases passing through the side walls of the susceptor.

[0043] The susceptor of the induction heating element may have any suitable form. For example, the susceptor may be elongated. The susceptor may have any suitable cross-section. For example, the susceptor may have a circular, elliptical, square, rectangular, triangular, or other polygonal cross-section.

[0044] In some embodiments, each susceptor is substantially identical. For example, the second susceptor may be substantially identical to the first susceptor. Each susceptor may be formed from the same material. Each susceptor may have substantially the same shape and dimensions. Making each susceptor substantially identical to the other susceptors may enable each susceptor to be heated to substantially the same temperature and at substantially the same rate when exposed to a given varying magnetic field.

[0045] In some embodiments, the second susceptor is different from the first susceptor in at least one characteristic. The second susceptor may be formed from a material different from that of the first susceptor. The second susceptor may have a shape and dimensions different from those of the first susceptor. The second susceptor may have a length longer than that of the first susceptor. Making each susceptor different from the other susceptors may enable each susceptor to be adapted to provide optimal heat for different aerosol-forming substrates.

[0046] In one example, the first aerosol-forming substrate may need to be heated to a first temperature to generate a first aerosol having desired characteristics, and the second aerosol-forming substrate may need to be heated to a second temperature different from the first temperature to generate a second aerosol having desired characteristics. In this example, the first susceptor may be formed from a first material suitable for heating the first aerosol-forming substrate to the 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 the second temperature.

[0047] In another embodiment, the aerosol-generating article may comprise a first aerosol-forming substrate having a first length and a second aerosol-forming substrate having a second length different from the first length, whereby heating the second aerosol-forming substrate generates a different amount of aerosol than heating the first aerosol-forming substrate. In this embodiment, the first susceptor may have a length substantially equal to the first length, and the second susceptor may have a length substantially equal to the second length.

[0048] In some preferred embodiments, the first susceptor is an elongate tubular susceptor and the second susceptor is an elongate tubular susceptor. In these preferred embodiments, the first susceptor and the second susceptor may be substantially aligned. In other words, the first susceptor and the second susceptor may be coaxially aligned.

[0049] The induction heating element may comprise any suitable number of susceptors. The induction heating element may comprise a plurality of susceptors. The induction heating element comprises at least two susceptors. For example, the induction heating element may comprise three, four, five, or six susceptors. When the induction heating element comprises more than two susceptors, intermediate elements may be disposed between each of the pairs of adjacent susceptors.

[0050] In some preferred embodiments, the susceptor may comprise a susceptor layer provided on a support body. Each of the first susceptor and the second susceptor may be formed from the support body and the susceptor layer. Disposing the susceptor in a varying magnetic field induces eddy currents in close proximity to the susceptor surface, an effect known as the skin effect. As a result, it is possible to form the susceptor from a relatively thin layer of susceptor material while ensuring that the susceptor is effectively heated in the presence of a varying magnetic field. Fabricating the susceptor from a support body and a relatively thin susceptor layer may facilitate the manufacture of a simple, inexpensive, and robust aerosol-generating article.

[0051] The support body may be formed from a material that is not susceptible to the effects of induction heating. This may advantageously reduce the heating of the surface of the susceptor that is not in contact with the aerosol-forming substrate, where the surface of the support body forms the surface of the susceptor that is not in contact with the aerosol-forming substrate.

[0052] The support body may include an electrically insulating material. As used herein, "electrically insulating" refers to a material having an electrical resistivity of at least 1 × 10 4 ohm meters (Ω·m) at 20 degrees Celsius.

[0053] The support body may comprise a heat insulating material for thermally insulating the first susceptor from the second susceptor. As used herein, the term "heat insulating material" is used to describe a material having a bulk thermal conductivity of about 40 watts per meter per kelvin (W / (m·K)) or less at 23 degrees Celsius and 50 percent relative humidity when measured using the modified transient plane source (MTPS) method.

[0054] Forming the support body from a heat insulating material may provide a thermal barrier between the susceptor layer and other components of the induction heating arrangement (such as the inductor coil surrounding the induction heater). This may advantageously reduce the heat transfer between the susceptor and other components of the induction heating system.

[0055] The support body may be a tubular support body, and the susceptor layer may be provided on the inner surface of the tubular support body. Providing the susceptor layer on the inner surface of the support body may position the susceptor layer adjacent to the aerosol-forming substrate within the cavity of the induction heater, improving the heat transfer between the susceptor layer and the aerosol-forming substrate.

[0056] In some preferred embodiments, the first susceptor comprises a tubular support body formed from a heat insulating material and a susceptor layer on the inner surface of the tubular support body. In some preferred embodiments, the second susceptor comprises a tubular support body formed from a heat insulating material and a susceptor layer on the inner surface of the tubular support body.

[0057] The susceptor may be provided with a protective outer layer, such as a protective ceramic layer or a protective glass layer. The protective outer layer may improve the durability of the susceptor and may facilitate cleaning of the susceptor. The protective outer layer may substantially surround the susceptor. The susceptor may comprise a protective coating formed from glass, ceramic, or an inert metal.

[0058] The induction heating element further comprises a separation portion between the first susceptor and the second susceptor.

[0059] The separation portion may be of any suitable size to thermally insulate the first susceptor from the second susceptor.

[0060] The induction heating element may comprise an intermediate element disposed between the first susceptor and the second susceptor. The intermediate element may be disposed within the separation portion between the first susceptor and the second susceptor. The intermediate element may extend between the first susceptor and the second susceptor. The intermediate element may contact the end of the first susceptor. The intermediate element may contact the end of the second susceptor. The intermediate element may be fixed to the end of the first susceptor. The intermediate element may be fixed to the end of the second susceptor. The intermediate element may connect the second susceptor to the first susceptor. When the intermediate element connects the second susceptor to the first susceptor, the intermediate element may provide structural support to the induction heating element. The intermediate element may advantageously enable the induction heating arrangement to be provided as a single non-disassemblable element that can be simply removed from and replaced in the induction heating arrangement.

[0061] The intermediate element may have any suitable form. 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 comprises an annular body defining an inner cavity. The intermediate element may be configured to allow gas to permeate from the outside of the intermediate element into the inner cavity. The intermediate element cavity may be configured to receive a portion of the aerosol-generating article. The intermediate element cavity may be an open cavity. The intermediate element cavity may be open at one end. The intermediate element cavity may be open at both ends.

[0062] In some preferred embodiments, the first susceptor and the second susceptor are tubular susceptors, and the intermediate element is a tubular intermediate element. In these embodiments, the tubular first susceptor, the tubular second susceptor, and the tubular intermediate element may be substantially aligned. The tubular first susceptor, the tubular intermediate element, and the tubular second susceptor may be arranged end-to-end in the form of a tubular rod. The inner cavities of the tubular first susceptor, the tubular intermediate element, and the tubular second susceptor may be substantially aligned. The inner cavities of the tubular first susceptor, the tubular intermediate element, and the tubular second susceptor may define an induction heating element cavity.

[0063] The intermediate element may be formed from any suitable material.

[0064] In a preferred embodiment, the intermediate element is formed from a material different from that of the first susceptor and the second susceptor.

[0065] The intermediate element may include a thermal insulation material for thermally insulating the first susceptor from the second susceptor. The intermediate element may include a material having a bulk thermal conductivity of about 100 milliwatts per meter per Kelvin (mW / (m·K)) or less at 23 degrees Celsius and 50 percent relative humidity when measured using the modified transient plane heat source (MTPS) method. Providing an intermediate element formed from a thermal insulation material at the separation between the first susceptor and the second susceptor may further reduce heat transfer between the first susceptor and the second susceptor. This may advantageously improve the ability of the induction heater to selectively heat individual portions of the aerosol-forming substrate. This may also make it possible to reduce the size of the separation between the first susceptor and the second susceptor and, as a result, reduce the size of the induction heater.

[0066] The intermediate element may include an electrical insulation material for electrically insulating the first susceptor from the second susceptor. The susceptor may include a material having an electrical resistivity of at least 1×10 4 ohm meters (Ωm) at 20 degrees Celsius.

[0067] The intermediate element may include at least one of a thermal insulation material for thermally insulating the first susceptor from the second susceptor and an electrical insulation material for electrically insulating the first susceptor from the second susceptor. In some preferred embodiments, the intermediate element includes a thermal insulation material for thermally insulating the first susceptor from the second susceptor and an electrical insulation material for electrically insulating the first susceptor from the second susceptor.

[0068] Particularly suitable materials for the intermediate element may include polymeric materials such as polyetheretherketone (PEEK), liquid crystal polymers such as Kevlar®, certain cements, glass, and ceramic materials such as zirconium dioxide (ZrO2), silicon nitride (Si3N4), and aluminum oxide (Al2O3).

[0069] The intermediate element may be gas permeable. In other words, the intermediate element is configured to allow gas to permeate through the intermediate element. The intermediate element is typically configured to allow gas to permeate from one side of the intermediate element to the other side of the intermediate element. The intermediate element may include an outer side and an inner side opposite the outer side. The intermediate element may be configured to allow gas to permeate from the outer side to the inner side.

[0070] In some embodiments, the intermediate element includes an air passage configured to allow passage of air through the intermediate element. In these embodiments, the intermediate element need not be formed from a gas permeable material. As a result, in some embodiments, the intermediate element is formed from a material that is not permeable to gas and includes an air passage configured to allow passage of air through the intermediate element. The intermediate element may include a plurality of air passages. The intermediate element may include any suitable number of air passages, such as two, three, four, five, or six air passages. When the intermediate element includes a plurality of air passages, the air passages may be regularly spaced on the intermediate element.

[0071] When the intermediate element is a tubular intermediate element that defines an inner cavity, the intermediate element may include an air passage configured to allow air to flow from the outer surface of the intermediate element into the inner cavity. The intermediate element may include an air passage extending from the outer surface to the inner surface. When the tubular intermediate element includes a plurality of air passages, the air passages may be regularly spaced around the perimeter of the tubular intermediate element.

[0072] The induction heating element may be provided within the induction heating arrangement.

[0073] The induction heating arrangement further includes an inductor coil. The induction heating arrangement preferably includes a first inductor coil and a second inductor coil.

[0074] The first inductor coil is configured such that a changing current supplied to the first inductor coil generates a fluctuating magnetic field. The first inductor coil is disposed with respect to the induction heating element such that a changing current supplied to the first inductor coil generates a fluctuating magnetic field that heats the first susceptor of the induction heating element.

[0075] The second inductor coil is configured such that a changing current supplied to the second inductor coil generates a fluctuating magnetic field. The second inductor coil is disposed with respect to the induction heating element such that a changing current supplied to the second inductor coil generates a fluctuating magnetic field that heats the second susceptor of the induction heating element.

[0076] The inductor coil may have any suitable form. For example, the inductor coil may be a flat inductor coil. The flat inductor coil may be wound in a spiral and substantially planar. The inductor coil is preferably a tubular inductor coil that defines an inner cavity. Typically, the tubular inductor coil is wound helically about an axis. The inductor coil may be elongated. It is particularly preferred that the inductor coil is an elongated tubular inductor coil. The inductor coil may have any suitable cross-section. For example, the inductor coil may have a circular, elliptical, square, rectangular, triangular, or other polygonal cross-section.

[0077] The inductor coil may be formed from any suitable material. The inductor coil is formed from a conductive material. The inductor coil is preferably formed from a metal or an alloy.

[0078] When the inductor coil is a tubular inductor coil, it is preferable that a part of the induction heating element is disposed inside the inner cavity of the inductor coil. It is particularly preferable that the first inductor coil is a tubular inductor coil and at least a part of the first susceptor is disposed inside the inner cavity of the first inductor coil. The length of the tubular first inductor coil may be substantially similar to the length of the first susceptor. It is particularly preferable that the second inductor coil is a tubular inductor coil and at least a part of the second susceptor is disposed inside the inner cavity of the second inductor coil. The length of the tubular second inductor coil may be substantially similar to the length of the second susceptor.

[0079] In some embodiments, the second inductor coil is substantially identical to the first inductor coil. In other words, the first inductor coil and the second inductor coil have the same shape, dimensions, and number of turns. In embodiments where the second susceptor is substantially identical to the first susceptor, it is particularly preferable that the second inductor coil is substantially identical to the first inductor coil.

[0080] In some embodiments, the second inductor coil is different from the first inductor coil. For example, the second inductor coil may have a different length, number of turns, or cross-sectional area from the first inductor coil. In embodiments where the second susceptor is different from the first susceptor, it is particularly preferable that the second inductor coil is different from the first inductor coil.

[0081] The first inductor coil and the second inductor coil may be arranged in any suitable arrangement. It is particularly preferable that the first inductor coil and the second inductor coil are coaxially aligned along the axis. When the first inductor coil and the second inductor coil are elongated tubular inductor coils, the first inductor coil and the second inductor coil may be coaxially aligned along the major axis such that the inner cavities of the coils are aligned along the major axis direction.

[0082] The induction heating arrangement may comprise any suitable number of induction coils. The induction heating element comprises a plurality of induction coils. The induction heating arrangement comprises at least two induction coils. Preferably, the number of induction coils in the induction heating arrangement is the same as the number of susceptors of the induction heating element. The number of induction coils in the induction heating arrangement may be different from the number of susceptors of the induction heating element. When the number of induction coils is the same as the number of susceptors, each induction coil is preferably arranged around a susceptor. It is particularly preferred that each induction coil extends substantially for the length of the susceptor around which the induction coil is arranged.

[0083] The induction heating element may comprise a magnetic flux concentrator. The magnetic flux concentrator may be arranged around the induction coil of the induction heating arrangement. The magnetic flux concentrator is configured to distort the alternating magnetic field generated by the induction coil towards the induction heating element.

[0084] Advantageously, by distorting the magnetic field towards the induction heating element, the magnetic flux concentrator can concentrate the magnetic field on the induction heating element. This may increase the efficiency of the induction heating arrangement compared to embodiments in which no magnetic flux concentrator is provided. As used herein, the phrase "concentrating the magnetic field" means distorting the magnetic field such that the magnetic energy density of the magnetic field increases at the location where the magnetic field "concentrates".

[0085] As used herein, the term "magnetic flux concentrator" refers to a component having a high relative permeability that acts to concentrate and guide the magnetic field or magnetic lines of force generated by the induction coil. As used herein, the term "relative permeability" refers to the ratio of the permeability of a material or medium (such as a magnetic flux concentrator) to the permeability of free space ("μ 0 "), where μ 0 is 4π × 10 -7 Newtons per square ampere (N·A -2 ).

[0086] As used herein, the term "high relative permeability" refers to a relative permeability of at least 5, for example at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 80, or at least 100 at 25 degrees Celsius. These exemplary values preferably refer to the relative permeability values at a frequency of 6 to 8 megahertz (MHz) and a temperature of 25 degrees Celsius.

[0087] The flux concentrator may be formed from any suitable material or combination of materials. The flux concentrator preferably includes a ferromagnetic material (such as a ferrite material), ferrite powder held in a binder, or any other suitable material including a ferrite material (such as ferrite iron, ferromagnetic steel, or stainless steel).

[0088] In some embodiments, the induction heating arrangement includes a flux concentrator disposed around a first induction coil and a second induction coil. In these embodiments, the flux concentrator is configured to distort the alternating magnetic field generated by the first induction coil towards the first susceptor of the induction heater and to distort the alternating magnetic field generated by the second induction coil towards the second susceptor of the induction heater.

[0089] In some of these embodiments, a portion of the flux concentrator extends into an intermediate element between the first susceptor and the second susceptor. The extension of a portion of the flux concentrator into the intermediate element between the first susceptor and the second susceptor may further distort the magnetic field generated by the first induction coil and the magnetic field generated by the second induction coil. This further distortion may result in the magnetic field generated by the first induction coil being further concentrated towards the first susceptor and the magnetic field generated by the second induction coil being further concentrated towards the second susceptor. This may further improve the efficiency of the induction heating arrangement.

[0090] In some embodiments, the induction heating arrangement comprises a plurality of magnetic flux concentrators. In some preferred embodiments, individual magnetic flux concentrators are disposed around each inductor coil. Providing a dedicated magnetic flux concentrator for each inductor coil may enable the magnetic flux concentrator to be optimally configured to optimally distort the magnetic field generated by the inductor coil. Such an arrangement may also enable the induction heating arrangement to be formed from modular induction heating units. Each induction heating unit may comprise an inductor coil and a magnetic flux concentrator. Providing modular induction heating units may facilitate the standardized manufacture of the induction heating arrangement and may enable the removal and replacement of individual units.

[0091] In some preferred embodiments, the induction heating arrangement comprises a first magnetic flux concentrator disposed around a first inductor coil and configured to distort a varying magnetic field generated by the first inductor coil towards a first susceptor, and a second magnetic flux concentrator disposed around a second inductor coil and configured to distort a varying magnetic field generated by the second inductor coil towards a second susceptor.

[0092] In these preferred embodiments, a portion of the first magnetic flux concentrator may extend into an intermediate element between the first susceptor and the second susceptor. In these preferred embodiments, a portion of the second magnetic flux concentrator may extend into an intermediate element between the first susceptor and the second susceptor. Extending a portion of the magnetic flux concentrator into the intermediate element between the susceptors may enable the magnetic flux concentrator to further distort the magnetic field generated by the inductor coil towards the susceptor.

[0093] The induction heating arrangement may further include an induction heating arrangement housing. The housing may hold together the induction heating element, the inductor coil, and the magnetic flux concentrator. This may serve to fix the relative arrangement of the components of the induction heating arrangement and to improve the connection between the components. The induction heating arrangement housing is preferably formed from an electrically insulating material.

[0094] When the induction heating arrangement comprises individual induction heating units including an inductor coil and a magnetic flux concentrator, each induction heating unit may comprise an induction heating unit housing. The induction heating unit housing may hold together the components of the induction heating unit and may improve the connection between the components. The induction heating unit housing is preferably formed from an electrically insulating material.

[0095] The induction heating arrangement may be provided within an aerosol generating device.

[0096] The aerosol generating device may comprise a power source. The power source may be any suitable type of power source. The power source may be a DC power source. In some preferred embodiments, the power source is a battery such as a rechargeable lithium-ion battery. The power source may be another form of charge storage device such as a capacitor. The power source may need to be recharged. The power source may have a capacity that allows for the accumulation of sufficient energy for one or more uses of the device. For example, the power source may have a capacity sufficient to allow for the continuous generation of aerosol for a period of about 6 minutes, or a multiple of 6 minutes, corresponding to the typical time taken to smoke one conventional cigarette. In another example, the power source may have a capacity sufficient to allow for a predetermined number of uses of the device, or for discontinuous activation. In one embodiment, the power source is a DC power source having a DC supply voltage in the range of about 2.5 volts to about 4.5 volts and a DC supply current in the range of about 1 ampere to about 10 amperes (corresponding to a DC power source in the range of about 2.5 watts to about 45 watts).

[0097] The aerosol generating device may comprise an induction heating arrangement and a controller connected to a power source. Specifically, the aerosol generating device may comprise a first inductor coil, a controller connected to a second inductor coil, and a power source. The controller is configured to control the supply of power from the power source to the induction heating arrangement. The controller may comprise a microprocessor, which may be a programmable microprocessor, a microcontroller, or an application specific integrated circuit chip (ASIC), or other electronic circuitry having the ability to provide control. The controller may further comprise additional electronic components. The controller may be configured to regulate the supply of current to the induction heating arrangement. The current may be continuously supplied to the induction heating arrangement after activation of the aerosol generating device, or may be supplied intermittently (e.g., for each puff).

[0098] Advantageously, the controller may comprise a DC / AC inverter, which may comprise a class C, class D, or class E power amplifier.

[0099] The controller may be configured to supply a varying current to an induction heating arrangement having any suitable frequency. The controller may be configured to supply a varying current to an induction heating arrangement having a frequency of from about 5 kilohertz to about 30 megahertz. In some preferred embodiments, the controller is configured to supply a varying current to an induction heating arrangement having a frequency of from about 5 kilohertz to about 500 kilohertz. In some embodiments, the controller is configured to supply a high-frequency varying current to the induction heating arrangement. As used herein, the term "high-frequency varying current" means a varying current having a frequency of from 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 from about 5 megahertz to about 8 megahertz).

[0100] The aerosol generating device may comprise a device housing. The device housing may be elongated. 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 these materials, or thermoplastic resins suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK), and polyethylene. The material is preferably light and not brittle.

[0101] The device housing may define a device cavity for receiving the aerosol forming substrate. The device cavity may be configured to receive at least a portion of the aerosol generating article. The device cavity may have any suitable shape and size. The device cavity may be substantially cylindrical. The device cavity may have a substantially circular cross-section.

[0102] The induction heating element may be disposed within the device cavity. The induction heating element may be disposed around the device cavity. If the induction heating element is a tubular induction heating element, the induction heating element may surround the device cavity. The inner surface of the induction heating element may form the inner surface of the device cavity.

[0103] The first induction coil and the second induction coil may be disposed within the device cavity. The first induction coil and the second induction coil may be disposed around the device cavity. The first induction coil and the second induction coil may surround the device cavity. The inner surfaces of the first induction coil and the second induction coil may form the inner surface of the device cavity.

[0104] The device may have a proximal end and a distal end opposite the proximal end. The device cavity is preferably disposed at the proximal end of the device.

[0105] The device housing may include an air inlet. The air inlet may be configured to allow ambient air to enter the device housing. The device housing may include any suitable number of air inlets. The device housing may include a plurality of air inlets.

[0106] 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.

[0107] When the intermediate element of the inductive heating element is gas permeable, the aerosol generating device may define an air flow path extending from the air inlet to the intermediate element of the inductive heating element. Such an air flow path may allow air to pass through the aerosol generating device from the air inlet, through the intermediate element, and into the device cavity.

[0108] 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 for receiving an 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 the distal end of the device cavity. The aerosol generating device may further include an annular seal facing towards the proximal end of the device cavity. The annular seal may extend into the device cavity. The annular seal may provide a substantially airtight seal between the device housing and the outer surface of the aerosol generating article received within the device cavity. This may reduce the volume of air drawn into the device cavity through any gap present between the outer surface of the aerosol generating article and the inner surface of the device cavity during use. This may increase the volume of air drawn into the aerosol generating article through the permeable intermediate element.

[0109] In some embodiments, the device housing comprises a mouthpiece. The mouthpiece may comprise at least one air inlet and at least one air outlet. The mouthpiece may comprise two or more air inlets. One or more of the air inlets may reduce the temperature of the aerosol before it is delivered to the user, and may also reduce the concentration of the aerosol before it is delivered to the user.

[0110] In some embodiments, the mouthpiece is provided as part of an aerosol-generating article. As used herein, the term "mouthpiece" refers to a part of an aerosol-generating system that is positioned in the user's mouth to directly inhale the aerosol generated by the aerosol-generating system from the aerosol-generating article received by the aerosol-generating device.

[0111] The aerosol-generating device may comprise a temperature sensor. The temperature sensor may be arranged to sense the temperature of the inductive heating element. The aerosol-generating device may comprise a first temperature sensor arranged to sense the temperature of the first susceptor. The aerosol-generating device may comprise a second temperature sensor arranged to sense the temperature of the second susceptor.

[0112] The aerosol-generating device may include a user interface for activating the device, such as a button to start heating the aerosol-generating article.

[0113] The aerosol-generating device may comprise a display indicating the state of the device or the aerosol-forming substrate.

[0114] The aerosol-generating device may comprise a smoking sensor for sensing when the user inhales the aerosol-generating system.

[0115] The aerosol generating device is preferably portable. The aerosol generating device may have a size comparable to that of a conventional cigar or cigarette. The aerosol generating device may have an overall length of about 30 millimeters to about 150 millimeters. The aerosol generating device may have an outer diameter of about 5 millimeters to about 30 millimeters.

[0116] The aerosol generating device may form part of an aerosol generating system.

[0117] The aerosol generating system may further comprise an aerosol generating article. The aerosol generating article may include a first aerosol-forming substrate and a second aerosol-forming substrate. When the aerosol generating article is received within the device cavity, at least a portion of the first aerosol-forming substrate may be received within the first portion of the device cavity, and at least a portion of the second aerosol-forming substrate may be received within the second portion of the device cavity.

[0118] The induction heating element that forms part of the induction heating arrangement of the aerosol generating device is configured to heat the aerosol-forming substrate.

[0119] The aerosol-forming substrate may contain nicotine. The nicotine-containing aerosol-forming substrate may be a nicotine salt matrix.

[0120] The aerosol-forming substrate may be a liquid. The aerosol-forming substrate may include solid and liquid components. The aerosol-forming substrate is preferably solid.

[0121] The aerosol-forming substrate may contain plant-derived materials. The aerosol-forming substrate may contain tobacco. The aerosol-forming substrate may contain a tobacco-containing material that includes volatile tobacco flavor compounds released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may contain non-tobacco materials. The aerosol-forming substrate may contain homogenized plant-derived materials. The aerosol-forming substrate may contain homogenized tobacco materials. The homogenized tobacco material may be formed by aggregating particulate tobacco. In a particularly preferred embodiment, the aerosol-forming substrate includes an assembly of crimped sheets of homogenized tobacco material. As used herein, the term "crimped sheet" means a sheet having a plurality of substantially parallel ridges or undulations.

[0122] The aerosol-forming substrate may contain at least one aerosol-forming agent. The aerosol-forming agent is any suitable well-known compound or mixture of compounds that facilitates the formation of a high-density stable aerosol during use 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 polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate, etc.), and aliphatic esters of monocarboxylic acids, dicarboxylic acids, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.), but are not limited thereto. Preferred aerosol-forming agents may include polyhydric alcohols or mixtures thereof (such as triethylene glycol, 1,3-butanediol, etc.). The aerosol-forming agent is preferably glycerin. When present, the homogenized tobacco material may have an aerosol-forming agent content of 5 weight percent or more on a dry weight basis (such as about 5 weight percent to about 30 weight percent on a dry weight basis). The aerosol-forming substrate may contain other additives and components (such as flavorants, etc.).

[0123] The aerosol-forming substrate may be included within the aerosol-generating article. The aerosol-generating device comprising the inductive heating arrangement may be configured to receive at least a portion of the aerosol-generating article. The aerosol-generating article may have any suitable form. The aerosol-generating article may have a substantially cylindrical shape. The aerosol-generating article may be substantially elongated. The aerosol-generating article may have a length and a circumference that is substantially perpendicular to that length.

[0124] The aerosol-forming substrate may be provided as an aerosol-generating segment containing the aerosol-forming substrate. The aerosol-generating segment may include a plurality of aerosol-forming substrates. The aerosol-generating segment may include a first aerosol-forming substrate and a second aerosol-forming substrate. In some embodiments, the second aerosol-forming substrate is substantially identical to the first aerosol-forming substrate. In some embodiments, the second aerosol-forming substrate is different from the first aerosol-forming substrate.

[0125] When the aerosol-generating segment includes a plurality of aerosol-forming substrates, the number of aerosol-forming substrates may be the same as the number of susceptors within the inductive heating body. Similarly, the number of aerosol-forming substrates may be the same as the number of inductor coils within the inductive heating arrangement.

[0126] The aerosol-generating segment may have a substantially cylindrical shape. The aerosol-generating segment may be substantially elongated. The aerosol-generating segment may also have a length and a circumference that is substantially perpendicular to that length.

[0127] When the aerosol-generating segment includes a plurality of aerosol-forming substrates, the aerosol-forming substrates may be arranged end-to-end along the axis of the aerosol-generating segment. In some embodiments, the aerosol-generating segment may include a separation between adjacent aerosol-forming substrates.

[0128] 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 about 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 about 7.2 millimeters.

[0129] 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 have a length of about 10 millimeters, or 12 millimeters.

[0130] The aerosol-generating segment preferably has an outer diameter that is substantially equal to the outer diameter of the aerosol-generating article. The outer diameter of the aerosol-generating segment may be from about 5 millimeters to about 12 millimeters. In one embodiment, the aerosol-generating segment may have an outer diameter of about 7.2 millimeters.

[0131] The aerosol-generating article may comprise a filter plug. The filter plug may be located at the proximal end of the aerosol-generating article. 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 have a length of about 7 millimeters.

[0132] The aerosol-generating article may comprise an outer wrapper. The outer wrapper may be formed from paper. The outer wrapper may be gas-permeable at the aerosol-generating segment. Specifically, in embodiments comprising a plurality of aerosol-forming substrates, the outer wrapper may comprise perforations or other air inlets at the interface between adjacent aerosol-forming substrates. Where a separation is provided between adjacent aerosol-forming substrates, the outer wrapper may comprise perforations or other air inlets at the separation. This may enable air that has not been drawn through another aerosol-forming substrate to be provided directly to the aerosol-forming substrate. This may increase the amount of air received by each aerosol-forming substrate. This may improve the characteristics of the aerosol generated from the aerosol-forming substrate.

[0133] The aerosol-generating article may also include a separation between the aerosol-forming substrate and the filter plug. The separation may be about 18 millimeters, but may range from about 5 millimeters to about 25 millimeters.

[0134] Also, of course, certain combinations of the various features described above may be implemented, supplied, and used independently.

[0135] Embodiments of the present disclosure will now be described by way of illustration only with reference to the accompanying drawings.

Brief Description of the Drawings

[0136]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0137] FIG. 1 shows a schematic view of an induction heating element 10 according to an embodiment of the present disclosure. The induction heating element 10 is an elongated tubular element having a circular cross-section. The induction heating element 10 comprises a first susceptor 12, a second susceptor 14, and a separation portion 15 between the first susceptor 12 and the second susceptor 14. The first susceptor 12 and the second susceptor 14 are each an elongated tubular element having a circular cross-section. The first susceptor 12 and the second susceptor 14 are coaxially aligned along the longitudinal axis A-A with ends in contact.

[0138] The induction heating element 10 comprises a cylindrical cavity 20 defined by the inner surfaces of the first susceptor 12 and the second susceptor 14 and open at both ends. The cavity 20 is configured to receive a portion of a cylindrical aerosol generating article (not shown) comprising an aerosol forming substrate, whereby the outer surface of the aerosol generating article is heated by the first susceptor and the second susceptor, thereby heating the aerosol forming substrate.

[0139] The cavity 20 includes three portions: a first portion 22 at a first end defined by the inner surface of the tubular first susceptor 12, a second portion 24 at a second end opposite the first end defined by the inner surface of the tubular second susceptor 14, and an intermediate portion 26 bounded by a separation portion 15 between the first susceptor 12 and the second susceptor 14. The first susceptor 12 is arranged to heat a first portion of the aerosol-generating article received within the first portion 22 of the cavity 20, and the second susceptor 14 is arranged to heat a second portion of the aerosol-generating article received within the second portion 24 of the cavity 20.

[0140] The first induction coil 32 is disposed around the first susceptor 12 and extends substantially the length of the first susceptor 12. Thus, the first susceptor 12 is substantially surrounded by the first induction coil 32 along its length. When a changing current is supplied to the first induction coil 32, the first induction coil 32 generates a fluctuating magnetic field that concentrates in the first portion 22 of the cavity 20. Such a fluctuating magnetic field generated by the first induction coil 32 induces eddy currents within the first susceptor 12, heating the first susceptor 12.

[0141] The second induction coil 34 is disposed around the second susceptor 14 and extends substantially the length of the second susceptor 14. Thus, the second susceptor 14 is substantially surrounded by the second induction coil 34 along its length. When a changing current is supplied to the second induction coil 34, the second induction coil 34 generates a fluctuating magnetic field that concentrates in the second portion 24 of the cavity 20. Such a fluctuating magnetic field generated by the second induction coil 34 induces eddy currents within the second susceptor 14, heating the second susceptor 14.

[0142] The separation part 15 between the first susceptor 12 and the second susceptor 14 provides a space that is not heated by induction when exposed to the alternating magnetic field generated by either the first inductor coil 32 or the second inductor coil 34 between the first susceptor 12 and the second susceptor 14. Further, the separation part 15 thermally insulates the second susceptor 14 from the first susceptor 12, thereby reducing the heat transfer rate between the first susceptor 12 and the second susceptor 14 as compared with induction heating elements in which the first susceptor and the second susceptor are arranged adjacent to each other and are in direct thermal contact. As a result, providing the separation part 15 between the first susceptor 12 and the second susceptor 14 enables selective heating of the first part 22 of the cavity 20 by the first susceptor 12 with minimal heating of the second part 24 of the cavity 20, and also enables selective heating of the second part 24 of the cavity 20 by the second susceptor 14 with minimal heating of the first part 22 of the cavity 20.

[0143] The first susceptor 12 and the second susceptor 14 may be heated simultaneously by simultaneously supplying a changing current to the first inductor coil 32 and the second inductor coil 34. Alternatively, the first susceptor 12 and the second susceptor 14 may be heated independently or alternately by supplying a changing current to the first inductor coil 32 without supplying current to the second inductor coil 34, and then supplying a changing current to the second inductor coil 34 without supplying current to the first inductor coil 32. It is also envisioned that the changing current may be supplied to the first inductor coil 32 and the second inductor coil 34 in sequence.

[0144] FIG. 2 shows a schematic diagram of an induction heating element according to another embodiment of the present disclosure. The induction heating element shown in FIG. 2 is substantially the same as the induction heating element shown in FIG. 1, and the same reference numerals are used to describe similar features.

[0145] The induction heating element 10 of FIG. 2 is an elongated tubular element having a circular cross-section. The induction heating element 10 includes a first susceptor 12 and a second susceptor 14. The difference between the induction heating element 10 of FIG. 1 and the induction heating element 10 of FIG. 2 is that the induction heating element 10 of FIG. 2 includes an intermediate element 16 disposed between the first susceptor 12 and the second susceptor 14. In the embodiment of FIG. 2, the separation between the first susceptor 12 and the second susceptor 14 still exists, but the separation is filled by the intermediate element 16. In this embodiment, the intermediate element 16 is fixed to the end of the first susceptor 12 and also fixed to the end of the second susceptor 14. Fixing the intermediate element 16 to the end of the first susceptor 12 and fixing the intermediate element 16 to the end of the second susceptor 14 indirectly connect the first susceptor 12 to the second susceptor 14. Advantageously, indirectly fixing the first susceptor 12 to the second susceptor 14 enables the formation of a single structure in which the induction heating element cannot be disassembled.

[0146] The intermediate element 16 includes a heat insulating material. Further, the heat insulating material is electrically insulating. In this embodiment, the intermediate element 16 is formed of a polymer material such as PEEK. Thus, the intermediate element 16 between the first susceptor 12 and the second susceptor 14 provides a space between the first susceptor 12 and the second susceptor 14 that is not inductively heated when exposed to the varying magnetic field generated by either the first inductor coil 32 or the second inductor coil 34. Further, the intermediate element 16 insulates the second susceptor 14 from the first susceptor 12 such that the heat transfer rate between the first susceptor 12 and the second susceptor 14 is reduced as compared to an inductive heating element in which the first susceptor and the second susceptor are disposed adjacent to each other and in direct thermal contact. The intermediate element 16 may also further reduce the heat transfer rate between the first susceptor 12 and the second susceptor 14 as compared to the separation portion 15 of the inductive heating element 10 of FIG. 1. As a result, providing the intermediate element 16 between the first susceptor 12 and the second susceptor 14 enables selective heating of the first portion 22 of the cavity 20 by the first susceptor 12 with minimal heating of the second portion 24 of the cavity 20, and also enables selective heating of the second portion 24 of the cavity 20 by the second susceptor 14 with minimal heating of the first portion 22 of the cavity 20.

[0147] Figures 3-7 show schematic views of an aerosol generation system according to an embodiment of the present disclosure. The aerosol generation system includes an aerosol generator 100 and an aerosol article 200. The aerosol generator 100 includes an inductive heating arrangement 110 according to the present disclosure. The inductive heating arrangement 110 includes an inductive heating element 120 according to the present disclosure.

[0148] Figures 3 and 4 show schematic views of the inductive heating element 120. The inductive heating element 120 includes a first susceptor 122, a second susceptor 124, a third susceptor 126, a first intermediate element 128, and a second intermediate element 130. The first intermediate element 128 is disposed between the first susceptor 122 and the second susceptor 124. The second intermediate element 130 is disposed between the second susceptor 124 and the third susceptor 126.

[0149] In this embodiment, each of the first susceptor 122, the second susceptor 124, and the third susceptor 126 is the same. Each susceptor 122, 124, 126 is an elongated tubular susceptor that defines an inner cavity. Each susceptor and its corresponding inner cavity are substantially cylindrical and have a circular cross-section that is constant along the length of the susceptor. The inner cavity of the first susceptor 122 defines a first region 134. The inner cavity of the second susceptor 124 defines a second region 136. The inner cavity of the third susceptor defines a third region 138.

[0150] Similarly, the first intermediate element 128 and the second intermediate element 130 are the same. The intermediate elements 128, 130 are tubular and define an inner cavity. Each intermediate element 128, 130 is substantially cylindrical and has a circular cross-section that is constant along the length of the intermediate element. The outer diameter of the intermediate elements 128, 130 is the same as the outer diameter of the susceptors 122, 124, 126 so that the outer surfaces of the intermediate elements 128, 130 may be aligned in the same plane as the outer surfaces of the susceptors 122, 124, 126. Also, the inner diameter of the intermediate elements 128, 138 is the same as the inner diameter of the susceptors 122, 124, 126 so that the inner surfaces of the intermediate elements 128, 130 may be aligned in the same plane as the inner surfaces of the susceptors 122, 124, 126.

[0151] The first susceptor 122, the first intermediate element 128, the second susceptor 124, the second intermediate element 130, and the third susceptor 126 are arranged coaxially and in contact end-to-end on the axis B-B. In this arrangement, the susceptors 122, 124, 126, and the intermediate elements 128, 130 form an elongated tubular cylindrical structure. This structure forms an induction heating element 120 according to one embodiment of the present disclosure.

[0152] The elongated tubular induction heating element 120 includes an inner cavity 140. The induction heating element cavity 140 is defined by the inner cavities of susceptors 122, 124, 126 and the inner cavities of intermediate elements 128, 130. The induction heating element cavity 140 is configured to receive the aerosol generating segment of the aerosol generating article 200, as will be described in more detail below.

[0153] The intermediate elements 128, 130 are formed from an electrically insulating heat insulating material. In this way, the susceptors 122, 124, 126 are substantially electrically insulated and thermally insulated from each other. Also, the material of the intermediate elements 128, 130 is substantially impermeable to gases. In this embodiment, the tubular induction heating element 120 is substantially impermeable to gases from the outer surface to the inner surface that define the induction heating element cavity 140.

[0154] Figures 5, 6, and 7 show schematic cross-sectional views of the aerosol generating device 100 and the aerosol generating article 200.

[0155] The aerosol generating device 100 includes a substantially cylindrical device housing 102 having a shape and size similar to that of a conventional cigarette. The device housing 102 defines a device cavity 104 at its 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 receive the aerosol generating segment 210 of the aerosol generating article 200. As a result, the length and diameter of the device cavity 104 are substantially similar to the length and diameter of the aerosol generating segment 210 of the aerosol generating article 200.

[0156] The aerosol generating device 100 further comprises a power source 106 in the form of a rechargeable nickel-cadmium battery, a controller 108 in the form of a printed circuit board including a microprocessor, an electrical connector 109, and an induction heating arrangement 110. The power source 106, the controller 108, and the induction heating arrangement 110 are all housed within the device housing 102. The induction heating arrangement 110 of the aerosol generating device 100 is disposed at the proximal end of the device 100 and is generally disposed around the device cavity 104. The electrical connector 109 is disposed at the distal end of the device housing 109 on the opposite side of the device cavity 104.

[0157] The controller 108 is configured to control the supply of power from the power source 106 to the induction heating arrangement 110. The controller 108 further comprises a DC / AC inverter including a class D power amplifier and is configured to supply a varying current to the induction heating arrangement 110. The controller 108 is also configured to control the recharge of the power source 106 from the electrical connector 109. In addition, the controller 108 comprises a smoking sensor (not shown) configured to sense when a user is sucking on an aerosol generating article received within the device cavity 104.

[0158] The induction heating arrangement 110 comprises 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.

[0159] The first induction heating unit 112 comprises a cylindrical tubular first inductor coil 150, a cylindrical tubular first magnetic flux concentrator 152 disposed around the first inductor coil 150, and a cylindrical tubular first inductor unit housing 154 disposed around the first magnetic flux concentrator 152.

[0160] The second induction heating unit 114 includes a cylindrical tubular second inductor coil 160, a cylindrical tubular second magnetic flux concentrator 162 disposed around the second inductor coil 160, and a cylindrical tubular second inductor unit housing 164 disposed around the second magnetic flux concentrator 162.

[0161] The third induction heating unit 116 includes a cylindrical tubular third inductor coil 170, a cylindrical tubular third magnetic flux concentrator 172 disposed around the third inductor coil 170, and a cylindrical tubular third inductor unit housing 174 disposed around the third magnetic flux concentrator 172.

[0162] As a result, each of the induction heating units 112, 114, 116 forms a substantially tubular unit having a circular cross-section. In each of the induction heating units 112, 114, 116, the magnetic flux concentrator extends across the proximal and distal ends of the inductor coil, whereby the inductor coil is disposed within the annular cavity of the magnetic flux concentrator. Similarly, each inductor unit housing extends across the proximal and distal ends of the magnetic flux concentrator, whereby the magnetic flux concentrator and the inductor coil are disposed within the annular cavity of the inductor unit housing. This arrangement enables the magnetic flux concentrator to concentrate the magnetic field generated by the inductor coil within the inner cavity of the inductor coil. This arrangement also enables the inductor unit housing to hold the magnetic flux concentrator and the inductor coil within the inductor unit housing.

[0163] The induction heating arrangement 110 further includes an induction heating element 120. The induction heating element 120 is disposed around the inner surface of the apparatus cavity 104. In this embodiment, the apparatus housing 102 defines the inner surface of the apparatus cavity 104. However, in some embodiments, it is envisioned that the inner surface of the apparatus cavity is defined by the inner surface of the induction heating element 120.

[0164] The induction heating units 112, 114, 116 are arranged around the induction heating element 120, whereby the induction heating element 120 and the induction heating units 112, 114, 116 are arranged concentrically around the device cavity 104. The first induction heating unit 112 is arranged around the first susceptor 122 at the distal end of the device cavity 104. The second induction heating unit 114 is arranged around the second susceptor 124 at the central portion of the device cavity 104. The third induction heating unit 116 is arranged around the third susceptor 126 at the proximal end of the device cavity 104. In some embodiments, it is envisioned that the magnetic flux concentrator may also extend into the intermediate element of the induction heating element to further distort the magnetic field generated by the inductor coil towards the susceptor.

[0165] The first inductor coil 150 is connected to the controller 108 and the power supply 106, and the controller 108 is configured to supply a varying current to the first inductor coil 150. When the varying current is supplied to the first inductor coil 150, the first inductor coil 150 generates a fluctuating magnetic field, which inductively heats the first susceptor 122.

[0166] The second inductor coil 160 is connected to the controller 108 and the power supply 106, and the controller 108 is configured to supply a varying current to the second inductor coil 160. When the varying current is supplied to the second inductor coil 160, the second inductor coil 160 generates a fluctuating magnetic field, which inductively heats the second susceptor 124.

[0167] The first inductor coil 170 is connected to the controller 108 and the power supply 106, and the controller 108 is configured to supply a varying current to the third inductor coil 170. When the varying current is supplied to the third inductor coil 170, the third inductor coil 170 generates a fluctuating magnetic field, which inductively heats the third susceptor 126.

[0168] The device housing 102 also defines an air inlet 180 that is in close proximity to the distal end of the device cavity 106. The air inlet 180 is configured to allow ambient air to be drawn into the device housing 102. An air flow path 181 is defined through the device between the air inlet 180 and an air outlet at the distal end of the device cavity 104 to allow air to be drawn from the air inlet 180 into the device cavity 104.

[0169] The aerosol generating article 200 is generally 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 comprises a cylindrical cellulose acetate filter plug 204 and a cylindrical aerosol generating segment 210 that are wrapped together by an outer wrapper 220 of cigarette paper.

[0170] The filter plug 204 is disposed at the proximal end of the aerosol generating article 200 and forms a mouthpiece of the aerosol generating system for the user to inhale the aerosol generated by the system.

[0171] The aerosol generation segment 210 is disposed at the distal end of the aerosol generating article 200 and has a length that is substantially equal to the length of the device cavity 104. The aerosol generation segment 210 includes a plurality of aerosol forming substrates including a first aerosol forming substrate 212 at the distal end of the aerosol generating article 200, a second aerosol forming substrate 214 adjacent to the first aerosol forming substrate 212, and a third aerosol forming substrate 216 adjacent to the second aerosol forming substrate 216 at the proximal end of the aerosol generation segment 210. Of course, in some embodiments, two or more of the aerosol forming substrates may be formed from the same material. However, in this embodiment, each of the aerosol forming substrates 212, 214, and 216 is different. The first aerosol forming substrate 212 comprises a collection of homogenized tobacco material without additional flavorants and a crimped sheet. The second aerosol forming substrate 214 includes a collection of homogenized tobacco material and a crimped sheet containing a flavorant in the form of menthol. The third aerosol forming substrate includes a flavorant in the form of menthol and does not include any other source of tobacco material or nicotine. Each of the aerosol forming substrates 212, 214, 216 also includes one or more aerosol forming bodies and additional components such as water, whereby heating of the aerosol forming substrate generates an aerosol having desirable sensory stimulating properties.

[0172] The proximal end of the first aerosol forming substrate 212 is exposed because it is not covered by the outer wrapper 220. In this embodiment, air can be drawn into the aerosol generation segment 210 at the proximal end of the article 200 through the proximal end of the first aerosol forming substrate 212.

[0173] In this embodiment, the first aerosol-forming substrate 212, the second aerosol-forming substrate 214, and the third aerosol-forming substrate 216 are arranged in end-to-end contact. However, in other embodiments, it is envisioned that a separation portion may be provided between the first aerosol-forming substrate and the second aerosol-forming substrate, and also a separation portion may be provided between the second aerosol-forming substrate and the third aerosol-forming substrate.

[0174] As shown in FIG. 7, when the aerosol-generating segment 210 of the aerosol-generating article 200 is received within the device cavity 104, 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 susceptor 122, to 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 first intermediate member 128, through the second region 136 of the second susceptor 124, to the second intermediate member 130. The length of the third aerosol-forming substrate 216 is such that the third aerosol-forming substrate 216 extends from the second intermediate member 130 to the proximal end of the device cavity 104.

[0175] In use, when the aerosol-generating article 200 is received within the device cavity 104, the user may draw on the proximal end of the aerosol-generating article 200 to inhale the aerosol generated by the aerosol-generating system. When the user draws on the proximal end of the aerosol-generating article 200, air is drawn into the device housing 102 at the air inlet 180 and drawn into the device cavity 104 along the airflow path 181. The air is drawn into the aerosol-generating article 200 at the proximal end of the first aerosol-forming substrate 212 through the outlet at the distal end of the device cavity 104.

[0176] In this embodiment, the controller 108 of the aerosol generating device 100 is configured to supply power to the inductor coils of the induction heating arrangement 110 in a predetermined order. The predetermined order is to supply a varying current to the first inductor coil 150 during a first inhalation from the user, and then, after the first inhalation is completed, to supply a varying current to the second inductor coil 160 during a second inhalation from the user, and then, after the second inhalation is completed, to supply a varying current to the third inductor coil 170 during a third inhalation from the user. The order restarts with the first inductor coil 150 at the fourth inhalation. This order results in the heating of the first aerosol-forming substrate 212 during the first puff, the heating of the second aerosol-forming substrate 214 during the second puff, and the heating of the third aerosol-forming substrate 216 during the third puff. Since all of the aerosol-forming substrates 212, 214, 216 of the article 100 are different, this order provides a different experience for the user with each puff in the aerosol generating system.

[0177] Of course, the controller 108 may be configured to supply power to the inductor coils in different orders or simultaneously, depending on the desired delivery of aerosol to the user. In some embodiments, the aerosol generating device may be controllable by the user to change the order.

[0178] FIG. 8 shows an induction heating arrangement according to another embodiment of the present invention. The induction heating arrangement 300 includes two modular induction heating units, namely a first induction heating unit 310 and a second induction heating unit 360. The modular induction heating units 310, 360 are identical independent units that are individually removable and replaceable within the induction heating arrangement 300. Providing such modular induction heating units makes it possible to manufacture the induction heating arrangement relatively inexpensively and simply. This is because it may be easier to standardize the manufacture of the separate modular induction heating units rather than the induction heating arrangement as a whole. Providing such modular induction heating units may also make it possible to easily customize the induction heating assembly.

[0179] The first induction heating unit 310 generally includes a tubular first susceptor 312, a tubular first inductor coil 314, a tubular first magnetic flux concentrator 316, and a tubular first induction heating unit housing 318.

[0180] The first susceptor 312 includes a tubular support body 320 formed from an electrically insulating heat insulating material such as alumina, and a susceptor layer 322 on the inner surface of the tubular support body 320. Intermediate elements 324 are provided at each end of the tubular support body 320 and overlap the ends of the susceptor layer 322. The intermediate elements 324 are also formed from an electrically insulating heat insulating material such as alumina.

[0181] The first inductor coil 314 is disposed around the outer surface of the first susceptor 312 and extends substantially the length of the first susceptor 312. Each end 326 of the first inductor coil 312 extends through the first magnetic flux concentrator 316 and the housing 318 to the outer surface of the first induction heating unit 310, whereby the first inductor coil 314 may be connected to a power source and supplied with a changing current.

[0182] The first flux concentrator 316 is disposed around the outer surface of the tubular first inductor coil 314 and extends outside the ends of the first inductor coil 314 and the first susceptor 312, but does not extend beyond the inner surface of the first susceptor 312. The intermediate element 324 is disposed between the first susceptor 312 and the first flux concentrator 316 and electrically insulates the susceptor layer of the first susceptor 312 from the first flux concentrator 316.

[0183] The first induction heating unit housing 318 extends around the outer surface of the first flux concentrator 316, outside the ends of the flux concentrator 316, and outside the inner surface of the first flux concentrator 316. The first induction heating unit housing 318 also extends outside the intermediate element 324 of the first susceptor 312, whereby the first susceptor 312, the first inductor coil 314, and the first flux concentrator 316 are held together. In this way, the first susceptor 312, the first inductor coil 314, the first flux concentrator 316, and the first induction heating unit housing 318 form a tubular unit having an inner cavity capable of receiving an aerosol-forming substrate. The first induction heating unit housing 318 is formed from an electrically insulating heat insulating material. In this embodiment, the first induction unit housing 318 is formed from a polymer such as PEEK that is injection molded outside the first susceptor 312, the first inductor coil 314, and the first flux concentrator 316.

[0184] The second induction heating unit 360 generally comprises a tubular second susceptor 362, a tubular second inductor coil 364, a tubular second flux concentrator 366, and a tubular second induction heating unit housing 368.

[0185] The second susceptor 362 includes a tubular support body 370 formed from an electrically insulating heat insulating material such as PEEK, and a susceptor layer 372 on the inner surface of the tubular support body 370. Intermediate elements 374 are provided at each end of the tubular support body 370 and overlap the ends of the susceptor layer 372. The intermediate elements 374 are also formed from an electrically insulating heat insulating material, which in this embodiment is a ceramic material such as zirconium dioxide (ZrO2).

[0186] The second inductor coil 364 is disposed around the outer surface of the second susceptor 362 and extends substantially the length of the second susceptor 362. Each end 376 of the second inductor coil 362 extends through the second magnetic flux concentrator 366 and the housing 368 to the outer surface of the second induction heating unit 360, whereby the second inductor coil 364 may be connected to a power source and supplied with a changing current.

[0187] The second magnetic flux concentrator 366 is disposed around the outer surface of the tubular second inductor coil 364 and extends outside the ends of the second inductor coil 364 and the ends of the second susceptor 362, but does not extend beyond the inner surface of the second susceptor 362. The intermediate element 374 is disposed between the second susceptor 362 and the second magnetic flux concentrator 366 and electrically insulates the susceptor layer of the second susceptor 362 from the second magnetic flux concentrator 366.

[0188] The second induction heating unit housing 368 extends around the outer surface of the second magnetic flux concentrator 366, outside the ends of the magnetic flux concentrator 366, and outside the inner surface of the second magnetic flux concentrator 366. The second induction heating unit housing 368 also extends outside the intermediate element 374 of the second susceptor 362, whereby the second susceptor 362, the second inductor coil 364, and the second magnetic flux concentrator 366 are held together. In this way, the second susceptor 362, the second inductor coil 364, the second magnetic flux concentrator 366, and the second induction heating unit housing 368 form a tubular unit having an inner cavity capable of receiving an aerosol-forming substrate. The second induction heating unit housing 368 is formed from an electrically insulating heat insulating material. In this embodiment, the second induction unit housing 368 is formed from a polymer such as PEEK that is injection molded outside the second susceptor 362, the second inductor coil 364, and the second magnetic flux concentrator 366.

[0189] The second induction heating unit 360 is stacked on top of the first induction heating unit 310 and forms an induction heating arrangement 300. The induction heating arrangement 300 generally forms a tubular unit that defines an inner cavity 380 for receiving an aerosol-forming substrate.

[0190] When the second induction heating unit 360 is stacked on top of the first induction heating unit 310, there is a separation between the first susceptor 312 and the second susceptor 362. The separation includes the intermediate elements 324, 374 from each of the first induction heating unit 310 and the second induction heating unit 360, and the end portions of the magnetic flux concentrators 316, 366 and the induction heating unit housings 318, 368 from each of the first induction heating unit 310 and the second induction heating unit 360. Such a separation provides effective heat insulation and electrical insulation between the susceptor layer 322 of the first susceptor 312 and the susceptor layer 372 of the second susceptor 362.

[0191] Of course, the above-described embodiments are merely specific examples, and other embodiments are contemplated in accordance with the present disclosure.

Claims

1. 1. An induction heating element for an aerosol generating system, comprising: a first susceptor, the first susceptor being a tubular susceptor defining an interior cavity for receiving an aerosol-forming substrate; a second susceptor, the second susceptor being a tubular susceptor defining an interior cavity for receiving the aerosol-forming substrate; a separator between the first susceptor and the second susceptor, the separator insulating the first susceptor from the second susceptor.

2. 2. The induction heating element of claim 1, further comprising an intermediate element disposed between the first susceptor and the second susceptor, the intermediate element including a thermal insulating material for insulating the first susceptor from the second susceptor.

3. The induction heating element of claim 2 , wherein the intermediate element comprises an electrically insulating material for electrically insulating the first susceptor from the second susceptor.

4. 4. The induction heating element of claim 2 or claim 3, wherein the intermediate element is a tubular intermediate element defining an inner cavity.

5. The induction heating element according to any one of claims 2 to 4, wherein the intermediate element is fixed to an end of the first susceptor.

6. The induction heating element of claim 5 , wherein the intermediate element is secured to an end of the second susceptor.

7. the first susceptor comprises a tubular support body formed from a thermally insulating material and a susceptor layer on an inner surface of the tubular support body; The induction heating element of any one of claims 1 to 6, wherein the second susceptor comprises a tubular support body formed from a thermal insulating material and a susceptor layer on an inner surface of the tubular support body.

8. 1. An induction heating arrangement comprising: The induction heating element according to any one of claims 1 to 7, A first inductor coil; a second inductor coil; a first inductor coil disposed relative to the induction heating element such that a varying current supplied to the first inductor coil generates a varying magnetic field that heats the first susceptor of the induction heating element; An induction heating arrangement, wherein the second inductor coil is disposed relative to the induction heating element such that a changing current supplied to the second inductor coil generates a varying magnetic field that heats the second susceptor of the induction heating element.

9. the first inductor coil is a tubular coil having an inner cavity, the first susceptor is disposed within the inner cavity of the first inductor coil, 9. The induction heating arrangement of claim 8, wherein the second inductor coil is a tubular coil having an inner cavity, and the second susceptor is disposed within the inner cavity of the second inductor coil.

10. 10. The induction heating arrangement of claim 9, further comprising a magnetic flux concentrator disposed about the first inductor coil and the second inductor coil, the magnetic flux concentrator configured to distort a varying magnetic field generated by the first inductor coil toward the first susceptor and to distort a varying magnetic field generated by the second inductor coil toward the second susceptor.

11. The induction heating arrangement of claim 10 , wherein a portion of the magnetic flux concentrator extends into the intermediate element between the first susceptor and the second susceptor.

12. a first magnetic flux concentrator disposed about the first inductor coil, the first magnetic flux concentrator configured to distort a varying magnetic field generated by the first inductor coil toward the first susceptor; 10. The induction heating arrangement of claim 9, further comprising: a second magnetic flux concentrator disposed about the second inductor coil, the second magnetic flux concentrator configured to distort a changing magnetic field generated by the second inductor coil toward the second susceptor.

13. an induction heating arrangement, a portion of the first magnetic flux concentrator extending into the intermediate element between the first susceptor and the second susceptor; The induction heating arrangement of claim 12 , wherein a portion of the second magnetic flux concentrator is at least one of an induction heating arrangement extending into the intermediate element between the first susceptor and the second susceptor.

14. An aerosol generating device comprising an induction heating arrangement according to any one of claims 8 to 13.

15. An aerosol generating device, comprising: a device housing defining a device cavity for receiving an aerosol-forming substrate; 1. An induction heating arrangement comprising: An induction heating element, a first susceptor disposed about a first portion of the device cavity; a second susceptor disposed about a second portion of the device cavity; an induction heating element including a separator between the first susceptor and the second susceptor, the separator insulating the first susceptor from the second susceptor; a first inductor coil disposed about at least a portion of the first susceptor and about the first portion of the device cavity; an induction heating arrangement including: a second inductor coil disposed about at least a portion of the second susceptor and the second portion of the device cavity; a power source connected to the induction heating arrangement and configured to provide a varying current to the first inductor coil and the second inductor coil; when the varying current is supplied to the first inductor coil, the first inductor coil generates a varying magnetic field which heats the first susceptor; When the varying current is supplied to the second inductor coil, the second inductor coil generates a varying magnetic field that heats the second susceptor.

16. 1. An aerosol generation system comprising:

1. An aerosol-generating article comprising: a first aerosol-forming substrate; a second aerosol-forming substrate; and The aerosol generating device according to claim 15, an aerosol generating system, wherein when the aerosol-generating article is received in the device cavity, at least a portion of the first aerosol-forming substrate is received in the first portion of the device cavity, and at least a portion of the second aerosol-forming substrate is received in the second portion of the device cavity.

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