Aerosol generator with thermally conductive elements

Abstract

An aerosol generator (10) is provided, comprising a thermally conductive element (28) that at least partially defines a chamber (16) for receiving at least a portion of an aerosol-generating article (102). The aerosol generator (10) also comprises an inductor coil (24) extending around at least a portion of the thermally conductive element (28). The aerosol generator (10) also comprises a power supply (42) and a control circuit (40) connected to the inductor coil (24) and configured to supply an alternating current to the inductor coil (24), thereby causing the inductor coil (24) to generate an alternating magnetic field when in use. An aerosol generation system (100) comprising the aerosol generator (10) is also provided.

Description

Technical Field

[0001] The present disclosure relates to an aerosol generating device for receiving an aerosol generating article, and an aerosol generating system including the aerosol generating device.

Background Art

[0002] It is known to release an aerosol from an aerosol forming substrate of an aerosol generating article by applying heat to a substrate, either burning the substrate or without combustion of the substrate. The aerosol generating article may be cylindrical such as a cigarette, and the aerosol forming substrate may contain tobacco material. It is known to apply heat to such an aerosol generating article and use a heat source outside the aerosol generating article to heat the aerosol forming substrate of the article.

[0003] However, external heat sources tend to heat the aerosol forming substrate non-uniformly. The aerosol forming substrate closest to the heat source is at the center of the aerosol generating article and is heated more than the aerosol forming substrate farther from the heat source.

[0004] It is also known to use a heat source located inside the aerosol forming substrate to heat the aerosol forming substrate of such articles. In some aerosol generating systems, the internal heat source is inductively heated using an induction coil positioned outside the aerosol generating article and a susceptor material positioned within the central region of the aerosol generating article. Heating the aerosol forming substrate internally avoids the heat that has to cross through the wrapper to reach the aerosol forming substrate. However, heating the aerosol forming substrate internally also results in heating of the substrate that is greatest at or closest to the internal heat source and decreases as the distance from the internal heat source into the substrate increases, resulting in the aerosol forming substrate being heated in a non-uniform manner.

[0005] Uneven heating of an aerosol-forming substrate can mean that not all available volatile materials are released from the aerosol-forming substrate. This is because increasing the level of heat applied to the substrate to completely extract volatile materials from it, whether using external or internal heating, can lead to unintended and undesirable combustion of the substrate near the heat source, which can result in the generation of undesirable compounds and flavors.

[0006] Therefore, it is desirable to provide an aerosol generator that facilitates efficient and uniform heating of an aerosol-forming substrate without requiring a complex heating arrangement. [Overview of the project]

[0007] According to a first aspect of the present disclosure, an aerosol generator is provided comprising a thermally conductive element that at least partially defines a chamber for receiving at least a portion of an aerosol-generating article. The aerosol generator also comprises an inductor coil extending around at least a portion of the thermally conductive element. The aerosol generator also comprises a power supply and control circuit connected to the inductor coil and configured to supply an alternating current to the inductor coil, thereby causing the inductor coil to generate an alternating magnetic field when in use.

[0008] As used herein, the term “aerosol generator” is used to describe a device that interacts with an aerosol-forming substrate to generate an aerosol. Preferably, the aerosol generator is a smoking device that interacts with an aerosol-forming substrate to generate an aerosol that can be directly inhaled into the user's lungs through the user’s mouth.

[0009] As used herein, the term “thermal conductive element” is used to describe an element comprising one or more thermal conductive materials having a bulk thermal conductivity of about 10 watts per meter Kelvin to about 500 watts per meter Kelvin, preferably about 15 watts per meter Kelvin to about 400 watts per meter Kelvin, when measured using the improved transient planar heat source (MTPS) method at 23 degrees Celsius and 50 percent relative humidity.

[0010] The inventors have recognized that when alternating current flows through the inductor coil during use, the inductor coil may exhibit heat loss in the form of resistive heating of the inductor coil. Advantageously, positioning a thermally conductive element may facilitate the resistive transfer of heat generated from the inductor coil to the aerosol-forming substrate of the aerosol-generating article received in the chamber. In embodiments in which the inductor coil is used to inductively heat a susceptor material or element positioned inside the aerosol-forming substrate, advantageously, the inductive heating of the susceptor element and the resistive heating of the inductor coil may provide simultaneous internal and external heating of the aerosol-forming substrate. Advantageously, simultaneous internal and external heating of the aerosol-forming substrate may facilitate more uniform heating of the aerosol-forming substrate.

[0011] Preferably, the inductor coil is positioned in direct contact with the outer surface of the thermal conductive element. Advantageously, direct contact between the inductor coil and the thermal conductive element may increase or maximize the resistive conduction of heat from the inductor coil to the thermal conductive element.

[0012] Preferably, the thermal conductive element is positioned so that it is in direct contact with the aerosol-generating article when the article is inserted into the chamber. Advantageously, direct contact between the thermal conductive element and the aerosol-generating article may increase or maximize heat conduction from the thermal conductive element to the aerosol-generating article.

[0013] Preferably, at least one of the control circuit and the thermal conductive element is configured to prevent inductive coupling between the thermal conductive element and the inductor coil during use.

[0014] As used herein, the term “inductive coupling” refers to the heating of a material when it is penetrated by an alternating magnetic field. Heating may be caused by the generation of eddy currents within the material. Heating may also be caused by magnetic hysteresis losses.

[0015] The control circuit may be configured to provide alternating current in the form of alternating current having a frequency selected to reduce or prevent inductive coupling between the thermal conductive element and the inductor coil during use. Preferably, the alternating current is provided at a frequency that reduces or prevents inductive coupling between the inductor coil and the thermal conductive element, and increases or maximizes inductive coupling between the inductor coil and the susceptor element. The frequency at which inductive coupling occurs varies depending on the materials, physical properties, and configuration of the inductor coil, thermal conductive element, and susceptor element, such as the inductance of the inductor coil, and the permeability of the materials from which each of the thermal conductive element and susceptor element is formed.

[0016] The thermally conductive element may be formed from a material that reduces or prevents inductive coupling between the inductor coil and the thermally conductive element.

[0017] The thermally conductive element may be formed from a non-conductive material. The non-conductive material may include at least one of glass, ceramic, silicone, polymer materials, and composite materials comprising two or more non-conductive materials.

[0018] In this specification, the term "conductive" means at least 0.8 × 10⁻⁶ 6 This term is used to refer to materials having an electrical conductivity of Siemens per meter. In this specification, the terms "non-conductive" and "electrically insulating" are used in relation to 0.8 × 10⁻⁶. 4 It is used to refer to materials with an electrical conductivity of less than Siemens per meter.

[0019] The thermally conductive element may be formed from a non-inductively heatable material. The non-inductively heatable material may include any of the non-conductive materials described above. The non-inductively heatable material may include a conductive material that exhibits insufficient or no inductive coupling with the inductor coil. The non-inductively heatable material may include a metal. The metal may include at least one of aluminum and paramagnetic steel. The paramagnetic steel may include austenitic steel. The thermally conductive element may be formed from 316 stainless steel.

[0020] The thermal conductive element may have any suitable shape. Preferably, the thermal conductive element has a tubular shape. Preferably, the thermal conductive element has a circular cross-sectional shape. The thermal conductive element may have a cylindrical shape with a certain cross-sectional size. The thermal conductive element may have a cylindrical shape, and at least a portion of the cylindrical shape has a tapered cross-sectional size. The tapered cross-sectional size may facilitate the insertion of an aerosol-generating article into the thermal conductive element.

[0021] The thermally conductive element may be formed from a cylindrical wall of a thermally conductive material. The cylindrical wall may have a wall thickness that extends radially. Preferably, the cylindrical wall has a number average thickness of at least 0.5 mm, or at least 1 mm, or at least 1.5 mm, or at least 2 mm in the radial direction. Preferably, the cylindrical wall has a number average thickness of less than 5 mm, or less than 4 mm, or less than 3 mm, or less than 2 mm in the radial direction.

[0022] The thermal conductive element may be a passive thermal conductive element. In other words, the thermal conductive element does not need to have the ability to generate heat itself. A passive thermal conductive element is arranged solely to conduct the heat resistively generated by the inductor coil.

[0023] The heat-conductive element may be an active heat-conductive element. In other words, the aerosol generating device may be configured to generate heat by resistive heating of the heat-conductive element.

[0024] In embodiments where the heat-conductive element is an active heat-conductive element, preferably, the control circuit is configured to supply a current from a power source to the heat-conductive element to resistively heat the heat-conductive element.

[0025] The heat-conductive element may comprise an electrically insulated substrate, for example, a substantially tubular electrically insulated substrate, and an electrically resistive track on the electrically insulated substrate. The electrical circuit may be configured to provide electricity from a power source to the electrically resistive track in use.

[0026] Suitable electrically insulating materials may include one or more of glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may include mica, alumina, or zirconia.

[0027] Suitable electrically resistive materials may include one or more of semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide, etc.), carbon, graphite, metals, alloys, and composite materials made of ceramic materials and metal materials. Such composite materials may include doped ceramics or may include undoped ceramics. An example of a suitable doped ceramic is doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal (registered trademark), and iron-manganese-aluminum-based alloys. The electrically resistive track may include a heating wire or filament, e.g., a Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire or filament.

[0028] The thermally conductive element may include a polymer material and at least one of graphite, graphite-derived materials, and hexagonal boron nitride dispersed in the polymer material. The polymer material may be referred to as a polymer matrix. At least one of graphite, graphite-derived materials, and hexagonal boron nitride may be present as filler particles within the polymer matrix.

[0029] The polymer material may be at least one of polyetheretherketone (PEEK) and liquid crystal polymer (LCP) or may include it. The thermally conductive element may include the polymer material in an amount of 22 weight percent to 33 weight percent of the thermally conductive element.

[0030] Examples of graphite-derived materials include at least one of expanded graphite and graphite nanoplatelets. The thermal conductive element may contain at least one of graphite, graphite-derived material, and hexagonal boron nitride in an amount of 62 to 69 weight percent of the thermal conductive element.

[0031] The thermal conductive element may further contain at least one additive dispersed within the polymer material. The at least one additive may include carbon black. The thermal conductive element may contain at least one additive in an amount of 5% to 9% by weight of the thermal conductive element. Advantageously, such actively heated thermal conductive elements may be easier to manufacture compared to other external heaters. More specifically, the inventors have observed that the thermoplastic properties of the polymer matrix may allow the composite polymer to be conveniently malleable, thereby allowing the composite polymer to take on a precise and controlled shape. Simultaneously, by controlling and adjusting the concentration and distribution of conductive filler particles dispersed within the polymer matrix, it is advantageous to provide an actively heated thermal conductive element capable of generating sufficient heat by the Joule effect to efficiently heat the aerosol-forming substrate of an aerosol-generating article thermally coupled to the thermal conductive element.

[0032] While not wishing to be constrained by theory, the inventors have found that by adjusting the formulation of the polymer matrix and the degree of dispersion of conductive filler particles within the polymer matrix, the conductivity and, consequently, the amount of heat resistively generated by the thermal conductive element when a voltage is applied to it can be controlled. Specifically, by adjusting the relative ratio of conductive filler to polymer in the polymer composite, it may be advantageously possible to ensure that the thermal conductive element made of the polymer composite exhibits a highly desirable level of resistivity. Other parameters such as the length and cross-sectional area of ​​the thermal conductive element may also be adjusted to fine-tune the resistive behavior of the thermal conductive element as a whole.

[0033] Preferably, the chamber comprises a first open end through which at least a portion of an aerosol-generating article may be inserted into the chamber, and a second closed end opposite the first open end.

[0034] Preferably, the aerosol generator includes at least one projection extending into the chamber from a closed second end of the chamber. Advantageously, at least one projection may abut the upstream end of an aerosol generating article received in the chamber, separating the upstream end of the aerosol generating article from the closed end of the chamber. Advantageously, separating the upstream end of the aerosol generating article from the closed end of the chamber may facilitate airflow into the aerosol generating article during use.

[0035] The aerosol generator may include a housing, in which the inductor coil, thermal conductive elements, power supply, and control circuit are located. Preferably, the housing includes an end wall defining a closed second end of the chamber, with at least one projection extending from the end wall into the chamber. Preferably, at least one projection is formed integrally with the end wall.

[0036] Preferably, at least one projection comprises at least three projections. Advantageously, providing at least three projections may facilitate the secure and correct positioning of the aerosol-generating article within the chamber. Preferably, the chamber has a longitudinal axis defining a first direction along which at least a portion of the aerosol-generating article may be inserted into the chamber, and the at least three projections are equidistant from each other in the circumferential direction around the longitudinal axis.

[0037] The aerosol generator may include a susceptor element. Advantageously, providing the susceptor element as part of the aerosol generator may eliminate the need to provide a susceptor element for each aerosol generating article. Advantageously, this may reduce the cost of each aerosol generating article.

[0038] As used herein, the term “susceptor element” refers to an element containing a material capable of converting magnetic field energy into heat. When a susceptor element is located in an alternating magnetic field, the susceptor is inductively 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.

[0039] Preferably, the susceptor element is an elongated susceptor element. Preferably, the elongated susceptor element extends into the chamber from the closed second end of the chamber. Preferably, at least a portion of the elongated susceptor element is positioned inside the inductor coil.

[0040] The susceptor element may be formed from any material that can be inductively heated to a temperature sufficient to aerosolize the aerosol-forming substrate. Suitable materials for the susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, and aluminum. Preferred susceptor elements contain metal or carbon. Preferably, the susceptor element contains or consists of ferromagnetic materials, such as ferrite iron, ferromagnetic steel, or stainless steel ferromagnetic alloys, ferromagnetic particles, and ferrite. Suitable susceptor elements may be aluminum or contain aluminum. The susceptor element preferably contains more than about 5 percent, preferably more than about 20 percent, more preferably more than about 50 percent or more than 90 percent of ferromagnetic or paramagnetic material. Preferred susceptor elements may be heated to a temperature above about 250 degrees Celsius.

[0041] The susceptor element may comprise a nonmetallic core having a metal layer disposed on top of the nonmetallic core. For example, the susceptor element may include one or more metal tracks formed on the outer surface of a ceramic core or substrate.

[0042] The susceptor element may have a protective outer layer, such as a protective ceramic layer or a protective glass layer. The protective outer layer may encase the susceptor element. The susceptor element may have a protective coating formed of glass, ceramic, or an inert metal on the outside of the core of the susceptor material.

[0043] The susceptor element may have any suitable cross-section. For example, the susceptor element may have a square, oval, rectangular, triangular, pentagonal, hexagonal, or similar cross-sectional shape. The susceptor element may have a planar or flat cross-sectional shape.

[0044] The susceptor element may be solid, hollow, or porous. Preferably, the susceptor element is solid.

[0045] In embodiments where the susceptor element has a planar or flat cross-sectional shape, the susceptor element preferably has a thickness of about 1 mm to about 8 mm, more preferably about 3 mm to about 5 mm. The thickness of the susceptor element is measured along the long axis of the aerosol generator. Preferably, the susceptor element has a width or diameter of about 3 mm to about 12 mm, more preferably about 4 mm to about 10 mm, and more preferably about 5 mm to about 8 mm. The width or diameter of the susceptor element is perpendicular to its thickness.

[0046] In embodiments where the susceptor element is an elongated susceptor element, the elongated susceptor element is preferably in the form of a pin, rod, blade, or plate. Preferably, the elongated susceptor element has a length of about 5 mm to about 15 mm, for example, about 6 mm to about 12 mm, or about 8 mm to about 10 mm. Preferably, the elongated susceptor element has a width of about 1 mm to about 8 mm, more preferably about 3 mm to about 5 mm. The elongated susceptor element may have a thickness of about 0.01 mm to about 2 mm. If the elongated susceptor element has a certain cross-section, for example, a circular cross-section, it has a preferred width or diameter of about 1 mm to about 5 mm.

[0047] Preferably, the thermal conductive element is formed from a first material and the susceptor element is formed from a second material, the first material being different from the second material. Advantageously, forming the thermal conductive element and the susceptor element from different materials may facilitate reduced or minimized inductive coupling between the inductor coil and the thermal conductive element, and increased or maximized inductive coupling between the inductor coil and the susceptor element.

[0048] Preferably, the inductor coil is arranged such that at least a portion of the aerosol-generating article is received within the inductor coil when the aerosol-generating article is inserted into the chamber.

[0049] An inductor coil may be formed from a coiled wire. The wire may comprise a conductive core and a coating on the conductive core. Preferably, the coating is electrically insulating. Advantageously, an electrically insulating coating may prevent electrical short circuits between adjacent windings of the inductor coil. Advantageously, an electrically insulating coating may electrically insulate the inductor coil from thermally conductive elements. The coating may contain at least one of polymers, ceramics, and glass. The coating may contain parylene.

[0050] The inductor coil may be formed from any suitable conductive material. Preferably, the inductor coil is formed from a metal or alloy. The inductor coil may be formed from at least one of copper, copper alloys, copper-nickel alloys, tungsten, aluminum, aluminum alloys, and steel. Suitable steels include stainless steel such as 316 stainless steel. In embodiments in which the inductor coil has a conductive core, the metal or metal alloy may form the conductive core.

[0051] The power supply may be a DC power supply. In one embodiment, the power supply is a DC power supply having a DC supply voltage in the range of approximately 2.5 volts to approximately 4.5 volts and a DC supply current in the range of approximately 1 ampere to approximately 10 amperes (corresponding to a DC power supply in the range of approximately 2.5 watts to approximately 45 watts).

[0052] The power supply may be configured to operate at high frequencies. As used herein, the term “high-frequency oscillating current” means an oscillating current having a frequency of about 500 kilohertz to about 30 megahertz. The high-frequency oscillating current may have a frequency of about 1 megahertz to about 30 megahertz, preferably about 1 megahertz to about 10 megahertz, and more preferably about 5 megahertz to about 8 megahertz.

[0053] The aerosol generator comprises a control circuit connected to an inductor coil and a power supply. The control circuit is configured to control the power supply from the power supply to the inductor coil. The control circuit may include a microprocessor, which may be a programmable microprocessor, a microcontroller, an application-specific integrated circuit chip (ASIC), or other electronic circuit capable of providing control. The control circuit may include further electronic components. The control circuit may be configured to regulate the supply of current to the inductor coil. The current may be supplied to the inductor coil continuously after the aerosol generator is started, or intermittently, such as with each smoke extraction. The control circuit may advantageously include a DC / AC inverter, which may include a Class D or Class E power amplifier.

[0054] The control circuit may be configured to supply electrical energy from the power source to the inductor coil as alternating current, thereby enabling the inductor coil to generate heat through one or a combination of i) resistive heating of the inductor coil and ii) heating of the susceptor element through inductive coupling with the susceptor of the inductor coil. The control circuit may be configured to adjust at least one parameter of the alternating current to change the inductive coupling with the susceptor element of the inductor coil, thereby adjusting the balance between the heat generated through resistive heating of the inductor coil and the heat generated through inductive coupling with the susceptor element of the inductor coil.

[0055] Preferably, at least one parameter includes the frequency of the alternating current. The inductive coupling between the inductor coil and the susceptor element changes with the frequency of the alternating current. The frequency is a value f associated with the alternating current that provides optimal coupling with the susceptor element, enabling nearly the entire energy transfer from the inductor coil to the susceptor element, and consequently creating an alternating magnetic field that yields most of the heat generated by the inductive heating of the susceptor element. サセプタThe frequency may be adjusted to have a frequency of f. The frequency is a value associated with an alternating current that provides little or no coupling with the susceptor element and allows the transfer of almost all of the energy remaining in the inductor coil, resulting in an alternating magnetic field that produces most of the heat generated by the resistive heating of the inductor coil. インダクタコイル The frequency may also be adjusted to have a value f associated with the alternating current, which results in a combination of inductive heating of the susceptor element and resistive heating of the inductor coil. 合計 These frequencies may be adjusted to have the following characteristics. Each of these frequencies varies depending on the materials, physical properties, and configuration of the inductor coil and susceptor element, such as the inductance of the inductor coil and the permeability of the material from which the susceptor element is formed.

[0056] The control circuit may be configured to supply alternating current to an inductor coil, thereby causing the inductor coil to generate an alternating magnetic field that inductively heats the susceptor element within the aerosol-generating article, and also to supply direct current to the inductor coil, resistively heating the inductor coil, thereby conductively heating the aerosol-generating article through a thermally conductive element. Advantageously, using a single coil to supply both heating power to the internal susceptor and to provide resistive heating of the coil itself provides two different heat sources at different locations for an aerosol-forming substrate having a structure that is less complex than a typical induction heating arrangement.

[0057] The control circuit may be configured to adjust the amount of heating provided by induction heating by adjusting the alternating current supplied to the inductor coil during the operation of the aerosol generator.

[0058] The control circuit may be configured to adjust the amount of heating provided by resistive heating by adjusting the DC current supplied to the inductor coil during the operation of the aerosol generator.

[0059] The control circuit may be configured to supply alternating current and direct current to the inductor coil at different times. For example, after the aerosol generator is started, the control circuit may be configured to initially supply alternating current to the inductor coil, and then supply direct current to the inductor coil. This may provide rapid aerosol generation at the start of a usage session, but may also provide complete and efficient heating of the entire aerosol-forming substrate throughout the entire usage session. At the beginning of a usage session, the susceptor may be in closer contact with the aerosol-forming substrate, so inductive heating of the internal susceptor may provide aerosol more quickly than external resistance heating. The internal susceptor may also heat up more quickly than the external inductor coil if the susceptor has a lower thermal mass than the inductor coil.

[0060] The control circuit may be configured to supply alternating current and direct current to the inductor coil in an alternating sequence. Alternating external and internal heating may be beneficial to avoid overheating of any part of the aerosol-forming substrate.

[0061] The control circuit may be configured to simultaneously supply both alternating current and direct current to the inductor coil. In this way, a larger amount of thermal energy can be transferred to the aerosol-forming substrate, generating a larger volume of aerosol, without either the susceptor or the inductor coil reaching a temperature at which any part of the aerosol-generating article may burn.

[0062] An aerosol generator comprising a control circuit configured to change at least one parameter of the alternating current, or configured to supply both alternating and direct current to an inductor coil, can change the mode of heat application to the aerosol-forming substrate by any one of the following heating regimes: a) Through the resistive heating of the inductor coil only, or primarily through it, b) By heating the susceptor element solely through inductive coupling with the susceptor element of the inductor coil, or primarily through that, c) A combination of resistive heating of the inductor coil and heating of the susceptor element through inductive coupling between the inductor coil and the susceptor element.

[0063] Preferably, the aerosol generator is portable. The aerosol generator may be about the size of a conventional cigar or cigarette. The aerosol generator may have an overall length of approximately 30 mm to approximately 150 mm. The aerosol generator may have an outer diameter of approximately 5 mm to approximately 30 mm.

[0064] The aerosol generator housing may be elongated. The housing may be made of 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 lightweight and not brittle.

[0065] The housing may include a mouthpiece. The mouthpiece may include at least one air intake and at least one air outlet. The mouthpiece may include two or more air intakes. One or more of the air intakes may reduce the temperature of the aerosol and reduce the concentration of the aerosol before it is delivered to the user.

[0066] Alternatively, the mouthpiece may be provided as part of the aerosol-generating article.

[0067] As used herein, the term “mouthpiece” refers to a portion of an aerosol generator that is positioned in the user’s mouth to allow direct inhalation of aerosols generated by the aerosol generator from an aerosol generating article received within the housing’s chamber.

[0068] The aerosol generator may include a user interface for activating the device, such as a button for starting the heating of the device, or a display for showing the status of the device or the aerosol-forming substrate.

[0069] A second aspect of this disclosure provides an aerosol generating system. The aerosol generating system comprises an aerosol generating device according to the first aspect of this disclosure, according to any of the embodiments described herein. The aerosol generating system also comprises an aerosol generating article comprising an aerosol-forming substrate.

[0070] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate having the ability to release volatile compounds capable of forming aerosols. Aerosol-generating articles may be disposable.

[0071] As used herein, the term "aerosol-forming substrate" refers to a substrate consisting of, or containing, an aerosol-forming material having the ability to release volatile compounds upon heating in order to generate aerosols.

[0072] The aerosol-generating article may include an article susceptor element. Preferably, the article susceptor element is positioned in direct contact with the aerosol-forming substrate. Preferably, the article susceptor element is an internal susceptor element positioned within the aerosol-forming substrate.

[0073] Preferably, the aerosol generating article is configured such that at least a portion of the article susceptor element is positioned within the inductor coil when the aerosol generating article is inserted into the chamber of the aerosol generating device.

[0074] The article susceptor element may have any of the optional or preferred features described above with respect to a susceptor element that forms part of an aerosol generator.

[0075] Preferably, the thermal conductive element is formed from a first material and the article susceptor element is formed from a second material, the first material being different from the second material. Advantageously, forming the thermal conductive element and the article susceptor element from different materials may facilitate reduced or minimized inductive coupling between the inductor coil and the thermal conductive element, and increased or maximized inductive coupling between the inductor coil and the article susceptor element.

[0076] The aerosol-forming substrate is preferably a solid aerosol-forming substrate. However, the aerosol-forming substrate may contain both solid and liquid components. Alternatively, the aerosol-forming substrate may be a liquid aerosol-forming substrate.

[0077] The aerosol-forming substrate preferably contains nicotine. More preferably, the aerosol-forming substrate contains tobacco. Alternatively, or additionally, the aerosol-forming substrate may contain a non-tobacco-containing aerosol-forming material.

[0078] When the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may contain one or more of the following: herb leaves, tobacco leaves, tobacco stems, puffed tobacco, and homogenized tobacco, for example, one or more of the following: powder, granules, pellets, fragments, twisted yarn, splinters, or sheets.

[0079] Optionally, the solid aerosol-forming substrate may contain tobacco or non-tobacco volatile flavor compounds, which are released upon heating of the solid aerosol-forming substrate. The solid aerosol-forming substrate may also contain, for example, one or more capsules containing additional tobacco volatile flavor compounds or non-tobacco volatile flavor compounds, which may melt during heating of the solid aerosol-forming substrate.

[0080] Optionally, the solid aerosol-forming substrate may be provided on or embedded within a thermally stable carrier. The carrier may take the form of a powder, granules, pellets, fragments, yarn, strips, or sheets. The solid aerosol-forming substrate may be deposited on the surface of the carrier, for example, in the form of a sheet, foam, gel, or slurry. The solid aerosol-forming substrate may be deposited over the entire surface of the carrier, or alternatively, in a pattern to provide non-uniform flavor delivery during use.

[0081] In preferred embodiments, the aerosol-forming substrate comprises homogenized tobacco material. As used herein, the term “homogenized tobacco material” refers to material formed by agglomerating particulate tobacco.

[0082] The aerosol-forming substrate preferably comprises an aggregate of homogenized tobacco material sheets. As used herein, the term “sheet” refers to a layered element having a width and length substantially greater than its thickness. As used herein, the term “aggregated” is used to describe a sheet that is wrapped, folded, or otherwise compressed or clamped substantially transversely to the longitudinal axis of the aerosol-generating article. Preferably, the aerosol-forming substrate comprises an aerosol-forming compound. As used herein, the term “aerosol-forming compound” is used to describe any suitable known compound or mixture of compounds that facilitates aerosol formation during use and is substantially resistant to thermal decomposition at the operating temperature of the aerosol-generating article.

[0083] Suitable aerosol-forming materials are known in the art and include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin); esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate); and aliphatic esters of monocarboxylic acids, dicarboxylic acids, or polycarboxylic acids (such as dimethyl dodecanediate and dimethyl tetradecanediate). Preferred aerosol-forming materials are polyhydric alcohols or mixtures thereof (such as propylene glycol, triethylene glycol, and 1,3-butanediol), and most preferably glycerin.

[0084] The aerosol-forming substrate may comprise a single aerosol-forming body. Alternatively, the aerosol-forming substrate may comprise a combination of two or more aerosol-forming bodies.

[0085] The present invention is defined in the claims. However, a non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with one or more features of any of the features described above, for example, one or more features of other embodiments, forms, or aspects described herein.

[0086] Example Ex1: Aerosol generator, A thermally conductive element that at least partially defines a chamber for receiving at least a portion of an aerosol-generating article, An inductor coil extending around at least a portion of the thermally conductive element, An aerosol generator comprising a power supply and control circuit, which are connected to an inductor coil and configured to supply alternating current to the inductor coil, thereby causing the inductor coil to generate an alternating magnetic field when in use.

[0087] Example Ex2: An aerosol generator according to Example 1, wherein the inductor coil is positioned in direct contact with the outer surface of the thermally conductive element.

[0088] Example Ex3: An aerosol generator according to Example 1 or 2, wherein the heat conductive element is arranged so as to be in direct contact with the aerosol generating article when the aerosol generating article is inserted into the chamber.

[0089] Example Ex4: An aerosol generator according to Example 1, 2, or 3, wherein at least one of the control circuit and the thermal conductive element is configured to prevent inductive coupling between the thermal conductive element and the inductor coil during use.

[0090] Example Ex5: An aerosol generator according to any of the preceding embodiments, wherein the control circuit is configured to provide an alternating current in the form of an alternating current having a frequency selected to prevent inductive coupling between a thermally conductive element and an inductor coil during use.

[0091] Example Ex6: An aerosol generator according to any of the preceding examples, wherein the thermally conductive element is formed from a non-conductive material.

[0092] Example Ex7: An aerosol generator according to any of the preceding examples, wherein the thermally conductive element is formed from a non-inductively heatable material.

[0093] Example Ex8: An aerosol generator according to any of the preceding examples, wherein the thermal conductive element includes at least one of a polymer material and a metal.

[0094] Example Ex9: An aerosol generator according to any of the preceding embodiments, wherein the thermal conductive element includes at least one of aluminum and paramagnetic steel.

[0095] Example Ex10: Aerosol generator according to Example 9, wherein the paramagnetic steel includes austenitic steel.

[0096] Example Ex11: An aerosol generator according to any of the preceding examples, wherein the thermal conductive element comprises a polymer material and at least one of graphite, graphite-derived material, and hexagonal boron nitride dispersed within the polymer material.

[0097] Example Ex12: An aerosol generator according to Example 11, wherein the polymer material comprises at least one of polyetheretherketone (PEEK) and liquid crystal polymer (LCP).

[0098] Example Ex13: An aerosol generator according to Example 11 or 12, wherein the thermal conductive element contains a polymer material in an amount of 22 to 33 weight percent of the thermal conductive element.

[0099] Example Ex14: An aerosol generator according to Example 11, 12, or 13, wherein the graphite-derived material comprises at least one of expanded graphite and graphite nanoplatelets.

[0100] Example Ex15: According to any of Examples 11 to 14, the thermal conductive element comprises at least one of graphite, graphite-derived material, and hexagonal boron nitride in an amount of 62 to 69 weight percent of the thermal conductive element.

[0101] Example Ex16: An aerosol generator according to any of Examples 11 to 15, wherein the thermally conductive element further comprises at least one additive dispersed within a polymer material.

[0102] Example Ex17: An aerosol generator according to Example 16, wherein at least one additive contains carbon black.

[0103] Example Ex18: An aerosol generator according to Example 16 or 17, wherein the thermal conductive element contains at least one additive in an amount of 5 to 9 weight percent of the thermal conductive element.

[0104] Example Ex19: An aerosol generator according to any of the preceding embodiments, wherein the power supply and control circuit are connected to a thermal conductive element and configured to provide current to the thermal conductive element during use, thereby resistively heating the thermal conductive element.

[0105] Example Ex20: An aerosol generator according to any of the preceding embodiments, wherein the chamber comprises an open first end through which at least a portion of an aerosol-generating article may be inserted into the chamber, and a closed second end opposite to the open first end.

[0106] Example Ex21: Aerosol generator according to Example 20, further comprising at least one projection extending into the chamber from a closed second end of the chamber.

[0107] Example Ex22: An aerosol generator according to Example 21, wherein at least one projection comprises at least three projections.

[0108] Example Ex23: An aerosol generator according to Example 22, wherein the chamber has a longitudinal axis defining a first direction along which at least a portion of an aerosol generating article may be inserted into the chamber, and at least three projections are equidistant from each other in the circumferential direction around the longitudinal axis.

[0109] Example Ex24: An aerosol generator according to any of the preceding embodiments, further comprising a housing, wherein an inductor coil, a thermal conductive element, a power supply, and a control circuit are located within the housing.

[0110] Example Ex25: An aerosol generator, a combination of Example 24 and any of Examples 20-23, wherein the housing comprises an end wall defining a closed second end of the chamber, and at least one projection extending from the end wall into the chamber.

[0111] Example Ex26: An aerosol generator according to Example 25, wherein at least one protrusion is integrally formed with the end wall.

[0112] Example Ex27: An aerosol generator according to any of Examples 20-26, further comprising an elongated susceptor element extending into the chamber from a closed second end of the chamber.

[0113] Example Ex28: An aerosol generator according to Example 27, wherein at least a portion of the elongated susceptor element is positioned inside the inductor coil.

[0114] Example Ex29: An aerosol generator according to Example 27 or 28, wherein the thermally conductive element is formed from a first material, the elongated susceptor element is formed from a second material, and the first material is different from the second material.

[0115] Example Ex30: An aerosol generator according to any of the preceding embodiments, wherein the inductor coil is arranged such that at least a portion of the aerosol-generating article is received within the inductor coil when the aerosol-generating article is inserted into the chamber.

[0116] Example Ex31: Aerosol generating system, Aerosol generator according to any of the preceding embodiments, An aerosol generating system comprising an aerosol generating article having an aerosol-forming substrate.

[0117] Example Ex32: An aerosol generating system according to Example 31, wherein the aerosol generating article is configured such that at least a portion of the aerosol forming substrate is positioned within the thermally conductive element when the aerosol generating article is inserted into the chamber.

[0118] Example Ex33: An aerosol generating system according to Example 31 or 32, wherein the aerosol generating article further comprises an article susceptor element.

[0119] Example Ex34: An aerosol generating system according to Example 33, wherein the aerosol generating article is configured such that at least a portion of the article susceptor element is positioned within the inductor coil when the aerosol generating article is inserted into the chamber.

[0120] Example Ex35: An aerosol generating system according to Example 33 or 34, wherein the thermal conductive element is formed from a first material and the article susceptor element is formed from a second material, and the first material is different from the second material.

[0121] The present invention will be further described with reference to the attached drawings, for illustrative purposes only. [Brief explanation of the drawing]

[0122] [Figure 1] Figure 1 shows a side cross-sectional view of an aerosol generator according to the first embodiment of the present invention. [Figure 2] Figure 2 shows an axial cross-sectional view of the aerosol generator shown in Figure 1 along line 1-1. [Figure 3] Figure 3 shows a side cross-sectional view of an aerosol generation system equipped with the aerosol generator shown in Figure 1. [Figure 4] Figure 4 shows a side cross-sectional view of an aerosol generator according to a second embodiment of the present invention. [Figure 5] Figure 5 shows a side cross-sectional view of an aerosol generation system equipped with the aerosol generator shown in Figure 4. [Modes for carrying out the invention]

[0123] Figures 1 and 2 show an aerosol generator 10 according to a first embodiment of the present invention. The aerosol generator 10 comprises a housing 12 that partially defines a chamber 16 for receiving a portion of an aerosol generating article. The chamber 16 comprises an open end 18 through which the aerosol generating article may be inserted into the chamber 16, and a closed end 20 opposite the open end 18.

[0124] The aerosol generator also includes a thermal conductive element 28 in the form of an austenitic steel tube. The thermal conductive element 28 partially defines the cylindrical wall 22 of the chamber 16 extending between an open end 18 and a closed end 20. The thermal conductive element 28 is positioned so that when the aerosol generating article is inserted into the chamber 16, the aerosol generating article is received within the thermal conductive element 28 and is in direct contact with the thermal conductive element 28. Advantageously, the direct contact between the thermal conductive element 28 and the aerosol generating article facilitates the transfer of heat from the thermal conductive element 28 to the aerosol generating article.

[0125] An inductor coil 24, comprising multiple windings 26, extends around the outer surface of a thermal conductive element 28. The inductor coil 24 is positioned so that its multiple windings are in direct contact with the outer surface of the thermal conductive element 28. Advantageously, positioning the inductor coil 24 in direct contact with the outer surface of the thermal conductive element 28 facilitates the transfer of heat generated by the resistive heating of the inductor coil 24 to the thermal conductive element 28. The inductor coil 24 and the thermal conductive element 28 are arranged concentrically around the central axis 36 of the aerosol generator 10.

[0126] As shown in Figure 2, the thermal conductive element 28 defines a plurality of channels 30 within its inner surface. Advantageously, the channels 30 facilitate airflow through the chamber 16 when the aerosol generating article is received in the chamber 16. In the embodiments shown in Figures 1 and 2, the thermal conductive element 28 defines three channels 30 equidistant from the central axis 36 of the aerosol generator 10. Those skilled in the art will understand that the thermal conductive element 28 may define more or fewer channels 30, and that the arrangement of the projections 38 around the central axis 36 may vary.

[0127] The housing 12 also defines a number of projections 38 extending into the chamber 16 from the closed end 20 of the chamber 16. As will be further described below, the projections 38 function to maintain a gap between the end of the aerosol generating article and the closed end 20 of the chamber 16 when the aerosol generating article is fully inserted into the chamber 16. In the embodiments shown in Figures 1 and 2, the housing 12 defines three projections 38 that are equidistant from the central axis 36 of the aerosol generator 10. Those skilled in the art will understand that the housing 12 may define more or fewer projections 38, and that the arrangement of the projections 38 at the closed end 20 of the chamber 16 may vary.

[0128] The aerosol generator 10 also includes a control circuit 40 and a power supply 42 connected to an inductor coil 24. The control circuit 40 is configured to supply alternating current from the power supply 42 to the inductor coil 24 in order to generate an alternating magnetic field.

[0129] Figure 3 shows a cross-sectional view of an aerosol generating system 100 comprising the aerosol generating device 10 and the aerosol generating article 102 shown in Figure 1.

[0130] The aerosol generating article 102 comprises an aerosol-forming substrate 104 in the form of a cigarette plug, a first hollow acetate tube 106, a second hollow acetate tube 108, a mouthpiece 110, and an outer wrapper 112. The aerosol generating article 102 may also include a susceptor element 114 disposed within the aerosol-forming substrate 104. During use, a portion of the aerosol generating article 102 is inserted into the chamber 16 such that the aerosol-forming substrate 104 and the susceptor element 114 are located inside the thermal conductive element 28 and the inductor coil 24. The control circuit 40 provides alternating current from the power supply 42 to the inductor coil 24, generating an alternating magnetic field that inductively heats the susceptor element 114, which heats the aerosol-forming substrate 104 and generates an aerosol. In addition, the heat generated in the inductor coil 24 due to resistance loss in the inductor coil 24 is conducted from the inductor coil 24 to the aerosol-forming substrate 104 by the thermal conductive element 28.

[0131] The airflow through the aerosol generating system 100 during use is illustrated by the dashed line 116 in Figure 3. When the user inhales the mouthpiece 110 of the aerosol generating article 102, negative pressure is generated in the chamber 16. The negative pressure draws air into the chamber 16 at the open end 18 of the chamber. The air entering the chamber 16 then flows along a plurality of channels 30 defined by the thermal conductive element 28. When the airflow reaches the closed end 20 of the chamber 16, the air enters the aerosol generating article 102 through the aerosol forming substrate 104. The airflow into the aerosol generating article 102 is facilitated by a gap maintained between the upstream end of the aerosol generating article 102 and the closed end 20 of the chamber 16 by a plurality of protrusions 38. As the airflow passes through the aerosol forming substrate 104, the aerosol generated by the heating of the aerosol forming substrate 104 is entrained in the airflow. Next, the aerosol flows along the length of the aerosol generating article 102 and through the mouthpiece 110 to the user.

[0132] Figure 4 shows a cross-sectional view of an aerosol generator 150 according to a second embodiment of the present invention. The aerosol generator 150 is similar to the aerosol generator 10 described with respect to Figures 1 and 2, and similar reference numerals are used to specify similar parts.

[0133] The aerosol generator 150 differs from the aerosol generator 10 only in the addition of a susceptor element 164. The susceptor element 164 has an elongated shape and extends into the chamber 16 from the closed end 20 of the chamber 16. The susceptor element 164 extends along the central axis 36 of the aerosol generator 150 such that the inductor coil 24 and the thermal conductive element 28 extend concentrically around the susceptor element 164.

[0134] Figure 5 shows a cross-sectional view of an aerosol generating system 170 comprising the aerosol generating device 150 and aerosol generating article 172 shown in Figure 4. The aerosol generating system 170 is similar to the aerosol generating system 100 described with respect to Figure 3, and similar reference numerals are used to specify similar parts.

[0135] The aerosol generating system 170 differs only in the absence of a susceptor element in the aerosol generating article 172. When the aerosol generating article 172 is inserted into the chamber 16, the susceptor element 164 of the aerosol generating device 150 is received into the aerosol forming substrate 104 of the aerosol generating article 172. With the aerosol generating article 172 inserted into the chamber 16, the operation of the aerosol generating system 170 is identical to the operation of the aerosol generating system 100 described with respect to Figure 3.

Claims

1. Aerosol generator, A thermally conductive element that at least partially defines a chamber for receiving at least a portion of an aerosol-generating article, the thermally conductive element being formed from at least one of a non-conductive material and a non-inductively heatable material, An inductor coil extending around at least a portion of the aforementioned heat-conducting element, A power supply and control circuit are connected to the aforementioned inductor coil and configured to supply alternating current to the inductor coil, thereby causing the inductor coil to generate an alternating magnetic field when in use. An aerosol generator equipped with the following features.

2. The aerosol generator according to claim 1, wherein the power supply and the control circuit are connected to the thermal conductive element and configured to supply current to the thermal conductive element during use to resistively heat the thermal conductive element.

3. Aerosol generator, A thermally conductive element that at least partially defines a chamber for receiving at least a portion of an aerosol-generating article, An inductor coil extending around at least a portion of the aforementioned heat-conducting element, A power supply and control circuit, wherein the power supply and control circuit are connected to an inductor coil and configured to supply alternating current to the inductor coil, thereby causing the inductor coil to generate an alternating magnetic field during use, and the power supply and control circuit are connected to a thermal conductive element and configured to supply current to the thermal conductive element during use to resistively heat the thermal conductive element, An aerosol generator equipped with the following features.

4. The aerosol generator according to claim 3, wherein the thermally conductive element is formed from at least one of a non-conductive material and a non-inductively heatable material.

5. The aerosol generating apparatus according to any one of claims 1 to 4, wherein the inductor coil is positioned in direct contact with the outer surface of the thermal conductive element.

6. The aerosol generating apparatus according to any one of claims 1 to 5, wherein the heat conductive element is arranged so as to be in direct contact with the aerosol generating article when the aerosol generating article is inserted into the chamber.

7. The aerosol generator according to any one of claims 1 to 6, wherein at least one of the control circuit and the thermal conductive element is configured to prevent inductive coupling between the thermal conductive element and the inductor coil during use.

8. The aerosol generator according to any one of claims 1 to 7, wherein the control circuit is configured to provide the alternating current in the form of an alternating current having a frequency selected to prevent inductive coupling between the thermal conductive element and the inductor coil during use.

9. The aerosol generating apparatus according to any one of claims 1 to 8, wherein the thermal conductive element includes at least one of a polymer material and a metal.

10. The aerosol generating apparatus according to any one of claims 1 to 9, wherein the thermal conductive element comprises at least one of aluminum and paramagnetic steel, and optionally the paramagnetic steel comprises austenitic steel.

11. The aerosol generator according to any one of claims 1 to 10, wherein the chamber comprises an open first end through which at least a portion of an aerosol generating article may be inserted into the chamber, and a closed second end opposite the open first end, and optionally the aerosol generator comprises at least one projection extending from the closed second end of the chamber into the chamber.

12. The aerosol generating device according to any one of claims 1 to 11, further comprising a susceptor element.

13. The aerosol generator according to claim 12, wherein the thermal conductive element is formed from a first material, the susceptor element is formed from a second material, and the first material is different from the second material.

14. an aerosol generation system, an aerosol generator according to any one of claims 1 to 13, an aerosol generating article comprising an aerosol-forming substrate, An aerosol generation system equipped with the following features.

15. The aerosol generating system according to claim 14, wherein the aerosol generating article further comprises an article susceptor element.

16. The aerosol generating system according to claim 15, wherein the thermal conductive element is formed from a first material, the article susceptor element is formed from a second material, and the first material is different from the second material.

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