Aerosol generator equipped with suspended inductor coils

Abstract

An aerosol generator (10) is provided, comprising a housing (12) defining 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) suspended within the chamber (16), as well as a power supply (42) and a control circuit (40) connected to the inductor coil (42). The inductor coil (42) is a helical coil including a first end (30) and a second end (32). The housing (12) is in contact with the inductor coil (42) only at the first end (30) and the second end (32). The power supply (42) and control circuit (40) are configured to supply alternating current to the inductor coil (24) so ​​that the inductor coil (24) generates an alternating magnetic field when in use. An aerosol generating 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 generate an aerosol from an aerosol generating substrate of an aerosol generating article by applying heat to the substrate without combustion or burning 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 heat the aerosol forming substrate of the article using a heat source outside the aerosol generating 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 heat the aerosol forming substrate of such articles using a heat source located inside the aerosol forming substrate. In some aerosol generating systems, the internal heat source is inductively heated using an induction coil located outside the aerosol generating article and a susceptor material located within the central region of the aerosol generating article. Heating the aerosol forming substrate internally avoids heat that has to cross through a 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 housing defining a chamber for receiving at least a portion of an aerosol-generating article. The aerosol generator also comprises an inductor coil suspended within the chamber, as well as a power supply and control circuit connected to the inductor coil. The power supply and control circuit are configured to supply an alternating current to the inductor coil such that the inductor coil generates 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 “suspended” refers to an arrangement in which less than 50% of the outer surface of the inductor coil is in contact with the inner surface of the chamber. The inventors have recognized that when alternating current flows through the inductor coil during use, the inductor coil may exhibit thermal losses in the form of resistive heating of the inductor coil.

[0010] Advantageously, positioning the inductor coil within the chamber can facilitate the transfer of heat generated by the resistance of the aerosol-generating article received within the chamber to the aerosol-forming substrate. In embodiments where 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] Advantageously, suspending the inductor coil within the chamber may reduce or minimize heat transfer from the inductor coil to the housing due to resistance. Advantageously, reducing or minimizing heat transfer from the inductor coil to the housing due to resistance heating may increase or maximize heat transfer from the inductor coil to the aerosol-forming substrate due to resistance.

[0012] Preferably, less than 40 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber. Preferably, less than 30 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber. Preferably, less than 20 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber. Preferably, less than 10 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber. Preferably, less than 5 percent of the outer surface of the inductor coil is in contact with the inner surface of the chamber.

[0013] Preferably, the inductor coil is a helical coil having a first end and a second end. Preferably, the housing contacts the inductor coil only at the first and second ends. Advantageously, by positioning the housing so that it contacts the inductor coil only at the first and second ends, conductive heat transfer from the inductor coil to the housing can be minimized.

[0014] The housing may include an inner surface that defines the chamber at least partially.

[0015] The first end and the second end of the inductor coil may abut against the inner surface of the housing. The inner surface of the housing may define a first recess and a second recess, with the first end of the inductor coil positioned in the first recess and the second end of the inductor coil positioned in the second recess. Alternatively, the inner surface of the housing may define a first slot and a second slot, with the first end of the inductor coil extending through the first slot and the second end of the inductor coil extending through the second slot. Advantageously, the first and second recesses, or the first and second slots, may facilitate the holding and correct positioning of the inductor coil within the chamber.

[0016] The inner surface of the housing may be overmolded over the first and second ends of the inductor coil to hold and position the inductor coil within the chamber.

[0017] 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.

[0018] Preferably, the outer surface of the inductor coil is spaced apart from the inner surface of the housing. Advantageously, the space between the outer surface of the inductor coil and the inner surface of the housing reduces or minimizes conductive heat transfer from the inductor coil to the housing. Preferably, the aerosol generator further comprises an airflow channel defined between the inner surface of the housing and the outer surface of the inductor coil, the airflow channel providing fluid communication between a first end of the chamber and a second end of the chamber.

[0019] Advantageously, by using the space between the inner surface of the housing and the outer surface of the inductor coil as an airflow channel, it may be possible to eliminate the need for a complex airflow arrangement within the chamber. For example, the inner surface of the housing can form the cylindrical wall of the chamber, which has a substantially smooth and continuous surface.

[0020] Advantageously, by using the space between the inner surface of the housing and the outer surface of the inductor coil as an airflow channel, heat transfer from the inductor coil to the housing can be further reduced or minimized. Advantageously, heat loss from the outer surface of the inductor coil can be absorbed by the airflow through the airflow channel, and the heated airflow can be absorbed by an aerosol-forming substrate received within the chamber.

[0021] Preferably, the annular gap has a radial number average width of at least 0.5 mm, or at least 1 mm, or at least 1.5 mm, or at least 2 mm. Preferably, the annular gap has a radial number average width of less than 5 mm, or less than 4 mm, or less than 3 mm, or less than 2 mm.

[0022] Preferably, the aerosol generator comprises a pressure sensor in fluid communication with an airflow channel defined by an annular gap. Advantageously, the relatively narrow airflow channel defined by the annular gap can amplify the pressure drop that occurs when a user inhales the aerosol generating system, including the aerosol generator. Advantageously, the amplified pressure drop can increase the sensitivity of the pressure sensor to user inhalation.

[0023] Preferably, the pressure sensor is configured to provide a signal to the control circuit indicating that a user has inhaled into an aerosol generating system, including an aerosol generator.

[0024] Preferably, the aerosol generating device comprises at least one projection extending into the chamber from a closed second end of the chamber. Advantageously, the at least one projection may abut against an upstream end of the aerosol generating article received within the chamber and be spaced apart so as to move the upstream end of the aerosol generating article away from the closed end of the chamber. Advantageously, moving the upstream end of the aerosol generating article away from the closed end of the chamber may promote airflow into the aerosol generating article during use.

[0025] Preferably, the housing comprises an end wall defining the closed second end of the chamber, and the at least one projection extends into the chamber from the end wall. Preferably, the at least one projection is formed integrally with the end wall.

[0026] Preferably, the at least one projection comprises at least three projections. Advantageously, providing at least three projections may facilitate 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 equidistantly spaced from each other in a circumferential direction around the longitudinal axis.

[0027] The aerosol generating device may comprise a susceptor element. Advantageously, providing a susceptor element as part of the aerosol generating device 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.

[0028] As used herein, the term "susceptor element" refers to an element comprising a material having the ability to convert the energy of a magnetic field into heat. When the susceptor element is located within 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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, formed on the outside of the core of the susceptor material.

[0033] 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.

[0034] The susceptor element may be solid, hollow, or porous. Preferably, the susceptor element is solid.

[0035] 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.

[0036] 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 preferably has a width or diameter of 1 mm to 5 mm.

[0037] Preferably, the inductor coil is positioned 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. Preferably, the inductor coil is positioned such that it is in direct contact with the aerosol-generating article when the aerosol-generating article is inserted into the chamber. Advantageously, direct contact between the inductor coil and the aerosol-generating article facilitates the conduction of heat generated by the resistance from the inductor coil to the aerosol-generating article.

[0038] 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, the electrically insulating coating can prevent electrical short circuits between adjacent windings of the inductor coil. Advantageously, the electrically insulating coating can electrically insulate the inductor coil from aerosol-generating articles received within the inductor coil. The coating may contain at least one of polymers, ceramics, and glass. The coating may contain parylene.

[0039] The coiled wire may have a square, rectangular, or flat cross-sectional shape. Advantageously, by forming the inductor coil from a coiled wire having a square, rectangular, or flat cross-sectional shape, the surface area of ​​the inductor coil in contact with the aerosol-generating article can be increased or maximized in embodiments where the inductor coil is arranged to be in direct contact with the aerosol-generating article.

[0040] In this specification, the term "conductive" means at least 0.8 × 10⁻⁶ 6 The term "electrical insulation" is used to refer to materials having an electrical conductivity of siemens per meter. In this specification, the term "electrical insulation" refers to materials with an electrical conductivity of 0.8 × 10⁻⁶. 4 It is used to refer to materials with an electrical conductivity of less than Siemens per meter.

[0041] An inductor coil can be formed from any suitable conductive material. Preferably, the inductor coil is formed from a metal or alloy. The inductor coil can 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.

[0042] 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).

[0043] 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.

[0044] 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.

[0045] 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.

[0046] As used herein, the term “inductive coupling” refers to the heating of a susceptor element when it is penetrated by an alternating magnetic field. Heating is caused by the generation of eddy currents in the susceptor element. Heating can also be caused by magnetic hysteresis losses.

[0047] 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. susceptor 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. inductor coil 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.total 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.

[0048] The control circuit may be configured to supply an alternating current to the inductor coil to resistively heat the inductor coil, thereby conducting the aerosol-generating article, by supplying an alternating current to the inductor coil so that the inductor coil generates an alternating magnetic field and induces heating of the susceptor element of the aerosol-generating article. Advantageously, using a single coil to provide both heating power to the internal susceptor and 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.

[0049] 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.

[0050] 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.

[0051] 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 to 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.

[0052] 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.

[0053] 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.

[0054] 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:

[0055] a) Through the resistive heating of the inductor coil only, or primarily through it,

[0056] b) By heating the susceptor element solely through inductive coupling with the susceptor element of the inductor coil, or primarily through that,

[0057] 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.

[0058] Preferably, the aerosol generator is portable. The aerosol generator may be comparable in size to 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.

[0059] 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 light and not brittle.

[0060] 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.

[0061] Alternatively, the mouthpiece may be provided as part of the aerosol-generating article.

[0062] 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.

[0063] The aerosol generator may include a user interface for activating the device, such as a button to start heating the device, or a display that shows the status of the device or the aerosol-forming substrate.

[0064] A second aspect of the present disclosure provides an aerosol generator comprising a housing defining a chamber for receiving at least a portion of an aerosol-generating article. The aerosol generator also comprises an inductor coil positioned within the chamber, the inductor coil being a helical coil having a first end and a second end, and the housing being in contact with the inductor coil only at the first and second ends of the inductor coil. The aerosol generator also includes a power supply and control circuit connected to the inductor coil and configured to supply an alternating current to the inductor coil so that the inductor coil generates an alternating magnetic field when in use.

[0065] Advantageously, positioning the inductor coil within the chamber can facilitate the transfer of heat generated by the resistance of the aerosol-generating article received within the chamber to the aerosol-forming substrate. In embodiments where 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.

[0066] Advantageously, by positioning the inductor coil within the chamber such that only the first and second ends of the inductor coil contact the housing, heat transfer due to resistance from the inductor coil to the housing can be reduced or minimized. Advantageously, reducing or minimizing heat transfer due to resistance heating from the inductor coil to the housing can increase or maximize heat transfer due to resistance from the inductor coil to the aerosol-forming substrate.

[0067] The aerosol generator may include any of the above-described selective or preferred features relating to the first aspect of the present disclosure.

[0068] A third aspect of this disclosure provides an aerosol generating system. The aerosol generating system comprises an aerosol generating device according to the first or second aspect of this disclosure, in any of the embodiments described herein. The aerosol generating system also comprises an aerosol generating article comprising an aerosol-forming substrate.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] Preferably, the aerosol-forming substrate is 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.

[0075] 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.

[0076] 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.

[0077] 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 or non-tobacco volatile flavor compounds, which may melt during heating of the solid aerosol-forming substrate.

[0078] 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, yarns, 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.

[0079] 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.

[0080] 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.

[0081] 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, 1,3-butanediol, and most preferably glycerin).

[0082] 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. [Examples]

[0083] 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 any one or more features of other embodiments, forms, or aspects described herein.

[0084] Example 1: Aerosol generator, A housing that defines a chamber for receiving at least a portion of an aerosol-generating article, An inductor coil suspended inside the chamber, An aerosol generator comprising a power supply and control circuit connected to an inductor coil, configured to supply alternating current to the inductor coil so that the inductor coil generates an alternating magnetic field when in use. Example 2: The aerosol generator according to Example 1, wherein the inductor coil is a helical coil including a first end and a second end. Example 3: The aerosol generator according to Embodiment 2, wherein the housing contacts the inductor coil only at the first and second ends of the inductor coil. Example 4: The aerosol generator according to Example 1, 2, or 3, wherein the housing includes an inner surface that at least partially defines the chamber. Example 5: An aerosol generator, a combination of Example 4 and Example 2 or Example 3, wherein the first end and the second end of the inductor coil each abut the inner surface of the housing. Example 6: The aerosol generator according to Embodiment 5, wherein the inner surface of the housing defines a first recess and a second recess, the first end of the inductor coil is positioned in the first recess, and the second end of the inductor coil is positioned in the second recess. Example 7: The aerosol generator according to Embodiment 5, wherein the inner surface of the housing defines a first slot and a second slot, the first end of the inductor coil extends through the first slot, and the second end of the inductor coil extends through the second slot. Example 8: An aerosol generator according to any one of Examples 4 to 7, wherein the outer surface of the inductor coil is spaced apart from the inner surface of the housing. Example 9: An aerosol generator according to any one of Examples 1 to 8, wherein the chamber includes 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. Example 10: An aerosol generator according to a combination of Examples 8 and 9, further comprising an airflow channel defined between the inner surface of the housing and the outer surface of the inductor coil, wherein the airflow channel provides fluid communication between the first end of the chamber and the second end of the chamber. Example 11: The aerosol generator according to Example 9 or 10, further comprising at least one projection extending into the chamber from a closed second end of the chamber. Example 12: The aerosol generator according to Example 11, wherein the housing includes an end wall defining a closed second end of the chamber, and at least one projection extends from the end wall into the chamber. Example 13: The aerosol generator according to Example 12, wherein at least one projection is integrally formed with the end wall. Example 14: The aerosol generator according to Example 11, 12, or 13, wherein at least one projection comprises at least three projections. Example 15: The aerosol generator according to Example 14, 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 spaced equidistant from each other in the circumferential direction around the longitudinal axis. Example 16: An aerosol generator according to any one of Examples 9 to 15, further comprising an elongated susceptor element extending into the chamber from a closed second end of the chamber. Example 17: The aerosol generator according to Example 16, wherein at least a portion of the elongated susceptor element is positioned inside the inductor coil. Example 18: An aerosol generator according to any one of Examples 1 to 17, 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. Example 19: An aerosol generator according to any one of Examples 1 to 18, wherein the inductor coil is arranged to be in direct contact with the aerosol generating article when the aerosol generating article is inserted into the chamber. Example 20: An aerosol generator according to any one of Examples 1 to 19, wherein the inductor coil is formed from coil wires, and the wires include a conductive core and a coating on the conductive core. Example 21: An aerosol generator according to any of Examples 1 to 20, wherein the coating is electrically insulating. Example 22: The aerosol generator according to Example 20 or 21, wherein the coating comprises at least one of polymer, ceramic, and glass. Example 23: The aerosol generator according to Example 22, wherein the coating contains parylene. Example 24: An aerosol generator according to any one of Examples 1 to 23, wherein the inductor coil contains metal. Example 25: The aerosol generator according to Example 24, wherein the metal comprises at least one of copper, copper alloys, copper-nickel alloys, tungsten, aluminum, aluminum alloys, and steel. Example 26: An aerosol generator comprising a combination of Example 24 or 25 and any of Examples 20-23, wherein a metal forms a conductive core. Example 27: Aerosol generation system, an aerosol generator according to any of Examples 1 to 26, An aerosol generating system comprising an aerosol generating article having an aerosol-forming substrate. Example 28: The aerosol generating system according to Example 27, wherein the aerosol generating article further comprises an article susceptor element. Example 29: The aerosol generating system according to Example 28, 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. Example 30: Aerosol generator, A housing that defines a chamber for receiving at least a portion of an aerosol-generating article, An inductor coil positioned within a chamber, wherein the inductor coil is a helical coil including a first end and a second end, and the housing is in contact with the inductor coil only at the first and second ends of the inductor coil, An aerosol generator comprising a power supply and a control circuit connected to the inductor coil and configured to supply an alternating current to the inductor coil so that the inductor coil generates an alternating magnetic field when in use. Example 31: The aerosol generator according to Example 30, further comprising at least one of the features of Examples 4 to 26. Example 32: Aerosol generation system, The aerosol generator described in Example 30 or 31, An aerosol generating system comprising an aerosol generating article having an aerosol-forming substrate. Example 33: The aerosol generating system according to Example 32, wherein the aerosol generating article further comprises an article susceptor element. Example 34: The aerosol generating system according to Embodiment 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.

[0085] The present invention will be further described, for illustrative purposes only, with reference to the attached drawings. [Brief explanation of the drawing]

[0086] [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]

[0087] 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 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. The cylindrical wall 22 of the chamber 16 extends between the open end 18 and the closed end 20.

[0088] The aerosol generator 10 also includes an inductor coil 24 with a plurality of windings 26 positioned within a chamber 16. The plurality of windings 26 of the inductor coil 24 define a lumen 28 into which a portion of the aerosol generating article is received when the aerosol generating article is inserted into the chamber 16. Advantageously, positioning the inductor coil 24 in direct contact with the aerosol generating article received within the chamber 16 facilitates the transfer of heat generated by the resistive heating of the inductor coil 24 to the aerosol generating article.

[0089] The inductor coil 24 comprises a first end 30 positioned toward the open end 18 of the chamber 16 and a second end 32 positioned toward the closed end 20 of the chamber 16. Each of the first end 30 and the second end 32 is received within a portion of the cylindrical wall 22 of the chamber 16, thereby holding the inductor coil 24 within the chamber 16. The cylindrical wall 22 of the chamber 16 may define a first recess and a second recess, slot, or opening into which the first end 30 and the second end 32 of the inductor coil 24 are respectively received. Alternatively, the first and second ends 30, 32 of the inductor coil 24 may be fixed to the cylindrical wall 22 of the chamber 16 by overmolding the housing 12 over the first and second ends 30, 32 of the inductor coil 24 during the manufacturing of the housing 12.

[0090] The inductor coil 24 is suspended within the chamber 16 by its first and second ends 30, 32 such that the windings 26 of the inductor coil 24 are spaced apart from the cylindrical wall 22 of the chamber 16. Thus, the inductor coil 24 contacts the housing 12 only at its first and second ends 30, 32. Separating the windings 26 of the inductor coil 24 from the cylindrical wall 22 of the chamber 16 defines an annular gap 34 between the cylindrical wall 22 of the chamber 16 and the windings 26 of the inductor coil 24. Advantageously, the annular gap 34 reduces or minimizes the transfer of heat generated by the resistive heating of the inductor coil 24 to the housing 12. Advantageously, the annular gap 34 facilitates airflow through the chamber 16 when an aerosol-generating article is received inside the chamber 16.

[0091] To facilitate the insertion of an aerosol-generating article into the chamber 16, the inductor coil 24 is arranged concentrically around the central axis 36 of the aerosol generator 10. To ensure secure positioning of the inductor coil 24 within the chamber 16, the first end 30 and the second end 32 of the inductor coil 24 are held by opposite portions of the cylindrical wall 22 of the chamber 16.

[0092] 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 further described below, the number of projections 38 functions 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.

[0093] 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.

[0094] 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.

[0095] 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 also comprises 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 and the inductor coil 24 such that the aerosol-forming substrate 104 and the susceptor element 114 are located inside the inductor coil 24. The control circuit 40 supplies 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.

[0096] 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. This negative pressure draws air into the chamber 16 at the open end 18 of the chamber. The air entering the chamber 16 then flows through the annular gap 34 between the inductor coil 24 and the cylindrical wall 22 of the chamber 16. 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 carried into the airflow. Next, the aerosol flows along the length of the aerosol generating article 102 and through the mouthpiece 110 to the user.

[0097] 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.

[0098] 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 from the closed end 20 of the chamber 16 into the chamber 16. The susceptor element 164 extends along the central axis 36 of the aerosol generator 150 such that the inductor coil 24 extends concentrically around the susceptor element 164.

[0099] Figure 5 shows a cross-sectional view of an aerosol generating system 170 comprising the aerosol generating device 150 and the aerosol generating article 172 shown in Figure 4. The aerosol generating system 170 is similar to the aerosol generating system 100 described with reference to Figure 3, and the same reference numerals are used to specify similar parts.

[0100] 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 housing that defines a chamber for receiving at least a portion of an aerosol-generating article, An inductor coil suspended within the chamber, wherein the inductor coil is a helical coil including a first end and a second end, and the housing contacts the inductor coil only at the first end and the second end of the inductor coil, An aerosol generator comprising a power supply and a control circuit connected to the inductor coil and configured to supply an alternating current to the inductor coil so that the inductor coil generates an alternating magnetic field when in use.

2. The aerosol generating apparatus according to claim 1, wherein the inner surface of the housing forms the cylindrical wall of the chamber.

3. The aerosol generating apparatus according to claim 2, wherein the cylindrical wall of the chamber has a smooth and continuous surface.

4. The aerosol generating apparatus according to claim 1, wherein the housing includes an inner surface that at least partially defines the chamber.

5. The aerosol generating apparatus according to claim 2 or 4, wherein each of the first end and the second end of the inductor coil abuts against the inner surface of the housing.

6. The aerosol generating apparatus according to claim 5, wherein the inner surface of the housing defines a first recess and a second recess, the first end of the inductor coil is positioned in the first recess, and the second end of the inductor coil is positioned in the second recess.

7. The aerosol generating apparatus according to claim 5, wherein the inner surface of the housing defines a first slot and a second slot, the first end of the inductor coil extends through the first slot, and the second end of the inductor coil extends through the second slot.

8. The aerosol generating apparatus according to any one of claims 2 to 7, wherein the outer surface of the inductor coil is spaced apart from the inner surface of the housing.

9. The aerosol generator according to any one of claims 1 to 8, wherein the chamber comprises an open first end through which at least a portion of the aerosol generating article can be inserted into the chamber, and a closed second end opposite to the open first end.

10. The aerosol generator according to a combination of claims 8 and 9, further comprising an airflow channel defined between the inner surface of the housing and the outer surface of the inductor coil, wherein the airflow channel provides fluid communication between a first end of the chamber and a second end of the chamber.

11. The aerosol generator according to claim 9 or 10, further comprising at least one projection extending into the chamber from the closed second end of the chamber.

12. The aerosol generator according to any one of claims 1 to 11, further comprising an elongated susceptor element extending into the chamber, wherein at least a portion of the elongated susceptor element is optionally positioned within the inductor coil.

13. The aerosol generator according to any one of claims 1 to 12, wherein the inductor coil is formed from a coil wire, the wire includes a conductive core and a coating on the conductive core, and optionally the coating is electrically insulating.

14. Aerosol generation system, an aerosol generator according to any one of claims 1 to 13, An aerosol generating system comprising an aerosol generating article having an aerosol-forming substrate.

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

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