Aerosol generator having a heater and a heat-conducting element

Abstract

An aerosol generating device (110) is provided. The aerosol generating device (110) comprises a tubular heat-conducting element (28) comprising a cylindrical inner surface (22) forming a curved surface, the cylindrical inner surface (22) at least partially defines a chamber (16) for receiving at least a portion of an aerosol generating article, so that the aerosol generating article received within the chamber (16) is in direct contact with the cylindrical inner surface (22). The aerosol generating device (110) also comprises a resistance heating element (133) and an inductor coil (124) formed separately from the tubular heat-conducting element (28). The inductor coil (124) extends around at least a portion of the heat-conducting element (28). The aerosol generating device (110) also comprises a power supply unit (42) and a control circuit (40). The power supply unit (42) and the control circuit (40) are connected to the resistance heating element (133) and configured to provide current to the resistance heating element (133) so that when used, the resistance heating element (133) heats the tubular heat conduction element (22). The power supply unit (42) and the control circuit (40) are connected to the inductor coil (124) and configured to provide alternating current to the inductor coil (124) so ​​that when used, the inductor coil (124) generates an alternating magnetic field.

Description

Technology Field

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

[0002] It is known that an aerosol is developed from an aerosol-forming substrate of an aerosol generating article without burning or combusting the substrate by applying heat to the substrate. The aerosol generating article may be cylindrical, and the aerosol-forming substrate may contain tobacco material. It is known that the aerosol-forming substrate of the article is heated by applying heat to such an aerosol generating article and using a heat source located outside the aerosol generating article.

[0003] However, the external heat source will tend to heat the aerosol-forming substrate unevenly. The aerosol-forming substrate closest to the heat source heats up more than the aerosol-forming substrate at the center of the aerosol-generating article located further away from the heat source.

[0004] In addition, it is 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 placed within the central region of the aerosol-generating article. Heating the aerosol-forming substrate internally avoids the heat that must be traversed through a wrapper to reach the aerosol-generating substrate. However, heating the aerosol-forming substrate internally also results in the aerosol-forming substrate being heated in a non-uniform manner, and the heating of the substrate is greatest at or closest to the internal heat source and decreases as the distance from the internal heat source into the substrate increases.

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

[0006] Therefore, it is desirable to provide an aerosol generating device that facilitates efficient and uniform heating of an aerosol-forming substrate without requiring a complex heating device.

[0007] According to the present disclosure, an aerosol generating device is provided. The aerosol generating device may include a tubular heat-conducting element. The tubular heat-conducting element may include a cylindrical inner surface forming a curved surface. The cylindrical inner surface may at least partially define a chamber for receiving at least a portion of an aerosol generating article. The aerosol generating article received within the chamber may be in direct contact with the cylindrical inner surface. The aerosol generating device may include a resistance heating element. The aerosol generating device may include an inductor coil. The inductor coil may extend around at least a portion of the heat-conducting element. The aerosol generating device may include a power supply and a control circuit. The power supply and the control circuit may be connected to the resistance heating element. The power supply and the control circuit are configured to provide current to the resistance heating element so that, in use, the resistance heating element may heat the tubular heat-conducting element. The power supply and the control circuit may be connected to the inductor coil. The power supply and control circuit can be configured to supply alternating current to the inductor coil, causing the inductor coil to generate an alternating magnetic field when in use.

[0008] According to the present disclosure, an aerosol generating device is also provided. The aerosol generating device comprises a tubular heat-conducting element comprising a cylindrical inner surface forming a curved surface, wherein the cylindrical inner surface at least partially defines a chamber for receiving at least a portion of an aerosol generating article, so that the aerosol generating article received within the chamber is in direct contact with the cylindrical inner surface. The aerosol generating device also comprises a resistance heating element and an inductor coil. The inductor coil extends around at least a portion of the heat-conducting element. The aerosol generating device comprises a power supply and a control circuit. The power supply and the control circuit are connected to the resistance heating element and configured to provide current to the resistance heating element so that the resistance heating element heats the tubular heat-conducting element when in use. The power supply and the control circuit may be connected to the inductor coil and configured to provide alternating current to the inductor coil so that the inductor coil generates an alternating magnetic field when in use.

[0009] As used herein, the term "aerosol generating device" is used to describe a device that generates an aerosol by interacting with an aerosol-forming substrate. Preferably, the aerosol generating device is a smoking device that generates an aerosol that can be inhaled directly into the user's lungs through the user's mouth by interacting with an aerosol-forming substrate.

[0010] As used herein, the term “thermal conductive element” is used to describe an element comprising one or more thermally conductive materials having a volumetric thermal conductivity of about 0.1 W / (m·K) (W per meter Kelvin) to about 500 W / (m·K), preferably about 1 W / (m·K) to about 400 W / (m·K), at 23°C and 50% relative humidity when measured using the modified transient plane source (MTPS) method.

[0011] As used herein, the term "curved surface" is used to describe a curved surface that is uniform and free of grooves, channels, and other discontinuities.

[0012] Advantageously, an aerosol generating device according to the present disclosure comprises both a resistance heating element and an inductor coil. Advantageously, this arrangement can facilitate both internal and external heating of an aerosol forming substrate of an aerosol generating article housed within a chamber. For example, the resistance heating element may be positioned to generate heat around the outside of the aerosol generating article, and the inductor coil may inductively heat a susceptor element positioned inside the aerosol forming substrate. Advantageously, providing both internal and external heating of the aerosol forming substrate can facilitate uniform heating of the aerosol forming substrate.

[0013] Advantageously, using separate inductor coils and resistance heating elements to provide induction heating and resistance heating, respectively, implies that the characteristics, shapes, and materials of the inductor coils and resistance heating elements can be individually adapted and optimized to heat the aerosol-forming substrate more efficiently. For example, the inductor coil can be optimized for induction heating, and the resistance heating element can be optimized for resistance heating.

[0014] Advantageously, a tubular thermal conductive element can facilitate uniform heat transfer from a resistance heating element to an aerosol generating article. Furthermore, the inventors recognized that when an alternating current flows through an inductor coil during use, the inductor coil may exhibit heat loss in the form of resistance heating of the inductor coil. Advantageously, the thermal conductive element can facilitate the transfer of heat generated by resistance heating from the inductor coil to an aerosol generating article housed in a chamber.

[0015] Advantageously, the uniform surface formed by the curved surface of the cylindrical inner surface of the tubular heat-conducting element can maximize the contact area between the tubular heat-conducting element and the aerosol-generating article, which can maximize heat transfer from the tubular heat-conducting element to the aerosol-generating article. This contrasts with other devices having a chamber for receiving the aerosol-generating article, the chamber defining one or more grooves or channels that define an airflow channel along the outer surface of the aerosol-generating article.

[0016] The tubular thermal conductive element may also be a resistance heating element. Advantageously, providing a single component that functions as both a tubular thermal conductive element and a resistance heater can simplify the design and configuration of the aerosol generator. For example, the tubular thermal conductive element may be formed from a material capable of resistance heating. In an embodiment where the tubular thermal conductive element is a resistance heating element, the power supply and control circuit are preferably configured to provide current to the tubular thermal conductive element so that the tubular thermal conductive element is resistance heated during use.

[0017] A resistance heating element may extend around at least a portion of a tubular thermal conductive element. Advantageously, a resistance heating element extending around at least a portion of a tubular thermal conductive element can facilitate heat transfer from the resistance heating element to the aerosol-forming substrate by the tubular thermal conductive element. Advantageously, using a tubular thermal conductive element to transfer heat from the resistance heating element to the aerosol-forming substrate can facilitate more uniform heating of the aerosol-forming substrate. The resistance heating element may surround the tubular thermal conductive element.

[0018] A resistance heating element may be positioned in direct contact with a tubular heat conduction element. Advantageously, in an embodiment where the resistance heating element is formed separately from the tubular heat conduction element, direct contact between the resistance heating element and the tubular heat conduction element can increase or maximize heat transfer from the resistance heating element to the tubular heat conduction element.

[0019] The resistance heating element may come into direct contact with the outer surface of the tubular heat-conducting element. For example, the resistance heating element may be a resistance heating coil extending around at least a portion of the tubular heat-conducting element.

[0020] A resistance heating element may be embedded at least partially within a tubular thermal conductor. Advantageously, embedding the resistance heating element at least partially within the tubular thermal conductor may increase or maximize heat transfer from the resistance heating element to the tubular thermal conductor. The resistance heating element may be a resistance heating coil embedded within the tubular thermal conductor such that the resistance heating coil extends around at least a portion of the chamber.

[0021] The resistance heating element may be a resistance heating coil extending around at least a portion of a tubular heat-conducting element.

[0022] The inductor coil can be positioned to be in direct contact with the outer surface of a tubular thermal conductive element. Advantageously, direct contact between the inductor coil and the thermal conductive element can increase or maximize the conduction of heat generated by resistance heating from the inductor coil to the thermal conductive element.

[0023] The inductor coil can be spaced apart from the tubular thermal conductive element so that the inductor coil does not come into direct contact with the tubular thermal conductive element. Advantageously, spaced apart from the tubular thermal conductive element makes it easier to form an airflow path between the inductor coil and the tubular thermal conductive element.

[0024] Preferably, the chamber comprises a first end defining an opening for receiving an aerosol generating article and a second end located opposite the first end. Preferably, the aerosol generating device comprises at least one air inlet and a housing defining at least one airflow passage extending between the at least one air inlet and the second end of the chamber, wherein the at least one airflow passage is disposed outside the chamber.

[0025] Advantageously, by positioning at least one airflow passage outside the chamber, it is facilitated that the cylindrical inner surface of the tubular heat-conducting element forms a uniform curved surface without grooves, channels, and other discontinuities.

[0026] At least one air inlet may be positioned adjacent to the opening. Preferably, at least one airflow passage extends between the outer surface of the tubular heat-conducting element and the inner surface of the housing. Advantageously, positioning at least one airflow passage between the outer surface of the tubular heat-conducting element and the inner surface of the housing can facilitate heating the airflow through the at least one airflow passage by heat generated by resistance heating from at least one of the resistance heating element and the inductor coil. Advantageously, heating the airflow passing through the at least one airflow passage can cause the airflow to be preheated before reaching the aerosol generating article contained within the chamber. At least a portion of the heating element may be positioned within the at least one airflow passage. At least a portion of the inductor coil may be positioned within the at least one airflow passage.

[0027] The chamber may define a longitudinal direction extending between the first end of the chamber and the second end of the chamber. At least one air inlet may extend through the side wall of the housing, and at least a portion of at least one airflow passage extends perpendicular to the longitudinal direction. Advantageously, by positioning at least one air inlet on the side wall of the housing, the risk of the user's lips accidentally blocking at least one air inlet during the use of the aerosol-generating article can be eliminated.

[0028] At least one air inlet may include a plurality of air inlets. Advantageously, by providing a plurality of air inlets, the risk of a user accidentally blocking all air inlets when using the aerosol generator can be reduced. Preferably, the air inlets are spaced at equal intervals from one another. Preferably, the air inlets are spaced symmetrically around a portion of the housing. The plurality of air inlets may include at least two, three, four, five, six, seven, eight, nine, or ten air inlets. The plurality of air inlets may include twelve, eleven, ten, nine, eight, seven, six, five, four, or fewer than three air inlets. Preferably, at least one airflow passage includes a plurality of airflow passages. Preferably, the plurality of airflow passages include a single airflow passage extending from each air inlet toward a second end of the chamber. The airflow passages extending from the air inlet can be combined into a single common airflow passage, and the single common airflow passage is fluidly connected to the second end of the chamber.

[0029] Preferably, the chamber has a circular cross-sectional shape. Advantageously, the circular cross-sectional shape can increase or maximize the contact area between the tubular heat-conducting element and the aerosol-generating article.

[0030] Preferably, the curved surface defines the circular cross-sectional shape of the chamber.

[0031] Preferably, the tubular thermal conductive element extends in the longitudinal direction, and the curved surface extends circumferentially with respect to the longitudinal direction. Preferably, the tubular thermal conductive element is positioned so that an aerosol generating article can be inserted into the chamber along the longitudinal direction.

[0032] Preferably, the circular cross-sectional shape of the chamber has a constant diameter in all directions perpendicular to the longitudinal direction. Advantageously, by providing a circular cross-sectional shape of the chamber having a constant diameter in all directions perpendicular to the longitudinal direction, the contact area between the tubular heat-conducting element and the aerosol-generating article can be increased or maximized.

[0033] Preferably, the circular cross-sectional shape of the chamber has a roundness of at least 0.999. As used herein, the term “roundness” of the shape is the ratio of the radius of the inscribed circle to the radius of the circumscribed circle of the shape. Advantageously, by providing a circular cross-sectional shape of the chamber having a roundness of at least 0.999, the contact area between the tubular heat-conducting element and the aerosol-generating article can be increased or maximized.

[0034] Preferably, the control circuit and the power supply are configured to provide direct current to the resistance heating element to resistively heat the resistance heating element.

[0035] The control circuit may be configured to provide a direct current to the resistance heating element so that the resistance heating element is heated to at least 80 degrees Celsius. Advantageously, by heating the resistance heating element to at least 80 degrees Celsius, it is ensured that the resistance heating element properly heats the aerosol-forming substrate so that steam can be generated. The control circuit may be configured to provide a direct current to the resistance heating element so that the resistance heating element is heated to 210 degrees Celsius or lower. Advantageously, by heating the resistance heating element to 210 degrees Celsius or lower, it is ensured that the resistance heating element does not burn or char the aerosol-forming substrate, because otherwise, undesirable compounds may be generated, which may produce an aerosol with a burnt taste for the user.

[0036] The control circuit can be configured to provide alternating current to the inductor coil and direct current to the resistance heating element at different times.

[0037] For example, the control circuit may be configured to provide alternating current to the inductor coil and then provide direct current to the resistance heating element. The control circuit may be configured to provide alternating current to the inductor coil during a first period. The control circuit may be configured to provide a second current to the resistance heating element during a second period after the first period. Advantageously, the aerosol-forming substrate may be non-uniform, and heating the aerosol-forming substrate via induction heating and then subsequently by resistance heating may heat different parts of the aerosol-forming substrate at different times. Because the aerosol-forming substrate may be non-uniform, this may result in aerosols with different aerosol characteristics being generated at different times.

[0038] The control circuit may be configured to provide a direct current to the resistance heating element and then provide an alternating current to the inductor coil. The control circuit may be configured to provide a direct current to the resistance heating element during a first period. The control circuit may be configured to provide an alternating current to the inductor coil during a second period after the first period. Advantageously, the aerosol forming substrate may be non-uniform, and different parts of the aerosol forming substrate may be heated at different times by heating the aerosol forming substrate through resistance heating and then through induction heating. Because the aerosol forming substrate may be non-uniform, this may result in aerosols with different aerosol characteristics being generated at different times.

[0039] The control circuit may be configured to detect when a user puffs the system. For example, the control circuit may be coupled to a pressure sensor, which is configured to detect a pressure drop when the user puffs the system. The control circuit may be configured to supply power to an inductor coil or a resistance heating element, or both the inductor coil and the resistance heating element, when the pressure sensor detects a pressure drop while the user puffs the system. For example, the control circuit may be configured to initiate a first period in response to the user puffing the system.

[0040] The control circuit may include a user-activable trigger. For example, the user-activable trigger may include a button or a switch. The control circuit may be configured to start a first period in response to the user-activable trigger being activated.

[0041] The control circuit is,

[0042] A predetermined number of puffs in the system being taken; or

[0043] A predetermined time from the first puff on the passing system; or

[0044] User-activable triggers that are activated; or

[0045] It may be configured to terminate the first period and start the second period in response to any one or more combinations of the above.

[0046] The control circuit can be configured to provide alternating current to the inductor coil and direct current to the resistance heating element in an alternating sequential manner. Advantageously, it may be beneficial to alternate induction and resistance heating to avoid overheating of any part of the aerosol-forming substrate.

[0047] The control circuit can be configured to simultaneously provide alternating current to the inductor coil and direct current to the resistance heating element. Advantageously, in this way, a larger amount of thermal energy can be transferred to the aerosol-forming substrate to generate a larger volume of aerosol, without the need for a susceptor or resistance heating element to reach a temperature at which any part of the aerosol-generating article can burn. This can be particularly beneficial, for example, after starting the aerosol-generating system or after using the aerosol-generating system in a low-temperature environment.

[0048] There are many possible ways to combine the induction heating of the susceptor with the heating of the resistance heating element. For example, the induction heating of the susceptor can be controlled to follow a specific profile throughout the course of a usage session, and the resistance heating of the resistance heating element can be controlled to follow a different profile throughout the course of a usage session. The profile can be selected to provide not only consistent aerosol delivery throughout the course of a usage session but also heating of substantially all aerosol-forming substrates.

[0049] The control circuit can be configured to adjust the alternating current supplied to the inductor coil to maintain the susceptor temperature at a target temperature or to follow a target temperature profile.

[0050] The control circuit can be configured to maintain the temperature of the resistance heating element at a target temperature or to adjust the direct current supplied to the resistance heating element to follow a target temperature profile.

[0051] The control circuit can be configured to adjust the amount of heat generated in the susceptor by the inductor coil as a result of the alternating current by changing the magnitude of the alternating current during device operation.

[0052] The control circuit can be configured to adjust the frequency of the alternating current during device operation to adjust the amount of heat generated in the susceptor by the inductor coil as a result of the alternating current.

[0053] The inductor coil may be a helical coil. In an embodiment where the resistance heating element includes a resistance heating coil, the resistance heating coil may be a helical coil. The resistance heating coil and the inductor coil may be co-wound. Advantageously, this enables a space-efficient arrangement in which two separate heating systems can both be positioned to be in direct contact with the outer surface of the tubular heat-conducting element.

[0054] A resistance heating coil can be wound around a winding axis. An inductor coil can be wound around the same winding axis as the resistance heating coil.

[0055] 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.

[0056] As used herein, the term “inductive coupling” refers to the heating of a material when 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.

[0057] The control circuit may be configured to supply alternating current in the form of an 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 supplied 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 depends on the material, physical properties, and composition of the inductor coil, the thermal conductive element, and the susceptor element, such as the inductance of the inductor coil and the permeability of the material or materials constituting the thermal conductive element and the susceptor element, respectively.

[0058] The inductor coil may extend between the first end and the second end. The electrical resistance between the first end and the second end of the inductor coil may be less than 250 milliohms, preferably less than 150 milliohms, and more preferably about 100 milliohms. A relatively low electrical resistance can ensure that power dissipated as heat in the inductor coil is minimized. This may be particularly advantageous in an embodiment where the aerosol generator also includes a resistance heating coil.

[0059] The resistance heating coil may extend between a first end and a second end. The electrical resistance between the first end and the second end of the resistance heating coil may be 100 milliohms to 2000 milliohms, preferably 150 milliohms to 1500 milliohms, more preferably 200 milliohms to 1000 milliohms. Advantageously, since the resistance heating coil may be configured to resistively heat an aerosol-forming substrate, a relatively high electrical resistance ensures that maximum power in the resistance heating coil is dissipated as heat.

[0060] Preferably, the electrical resistance of the resistance heating coil is greater than the electrical resistance of the inductor coil. The electrical resistance of the resistance heating coil may be at least twice as large as the electrical resistance of the inductor coil. The electrical resistance of the resistance heating coil may be at least five times larger than the electrical resistance of the inductor coil. The electrical resistance of the resistance heating coil may be at least ten times larger than the electrical resistance of the inductor coil.

[0061] The thermal conductive element can be formed of a material that reduces or prevents inductive coupling between the inductor coil and the thermal conductive element.

[0062] The thermal conductive element may be formed from an electrically nonconductive material. The electrically nonconductive material may include at least one of glass, ceramic, silicon, polymeric material, and a composite material comprising two or more electrically nonconductive materials. Suitable ceramics may include at least one of alumina, aluminum nitrate, and zirconia. Advantageously, alumina, aluminum nitrate, and zirconia have been found to possess suitable thermal properties that ensure efficient transfer of heat to an aerosol-forming substrate.

[0063] The term "electrical conductivity" is at least 0.8 x 10 per meter 6 Used herein to refer to Siemens' electrically conductive materials. The terms "electrically non-conductive" and "electrically insulating" refer to 0.8 x 10⁻⁶ per meter 4 It is used herein to refer to materials having electrical conductivity less than Siemens.

[0064] The thermal conductive element may be formed from a non-conductive heating material. The non-conductive heating material may include any of the aforementioned electrically nonconductive materials. The non-conductive heating material may include an electrically conductive material having weak or no inductive coupling with the inductor coil. The non-conductive heating 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 thermal conductive element may be formed from 316 stainless steel.

[0065] The heat-conducting element is tubular in shape. Preferably, the heat-conducting element has a circular cross-sectional shape. The heat-conducting element may be cylindrical in shape having a constant cross-sectional size along the length of the heat-conducting element. The heat-conducting element may be cylindrical, and at least a portion of the cylindrical shape has a tapered cross-sectional size. The tapered cross-sectional size can facilitate the insertion of an aerosol-generating article into the heat-conducting element.

[0066] The thermal conductive element may be formed by a cylindrical wall of a thermally conductive material. The cylindrical wall may have a wall thickness extending in the radial direction. Preferably, the cylindrical wall has a number average thickness of at least 0.5 millimeters, or at least 1 millimeter, or at least 1.5 millimeters, or at least 2 millimeters in the radial direction. Preferably, the cylindrical wall has a number average thickness of less than 5 millimeters, or less than 4 millimeters, or less than 3 millimeters, or less than 2 millimeters in the radial direction.

[0067] In an embodiment where the tubular thermal conductive element is a resistance heating element, the thermal conductive element may include an electrical insulating substrate, such as a substantially tubular electrical insulating substrate, and an electrical resistance track formed on the electrical insulating substrate. The control circuit may be configured to provide current from a power supply to the electrical resistance track during use.

[0068] Suitable electrical insulating materials may include one or more of glass, ceramics, anodized metals, coated metals, and polyimides. Ceramics may include mica, alumina, or zirconia.

[0069] Suitable electrical resistance materials may include one or more of semiconductors such as doped ceramics, electrically "conductive" ceramics (e.g., molybdenum disilide), carbon, graphite, metals, metal alloys, and composite materials composed of ceramic materials and metal materials. Such composite materials may include doped ceramics or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminum-, titanium-, zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese-, and iron-containing alloys, and superalloys based on nickel, iron, cobalt, stainless steel, Timetal®, and iron-manganese-aluminum alloys. The electric resistance track may include a heating wire or filament, such as Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire or filament.

[0070] The thermal conductive element may comprise a polymer material and at least one of graphite, a graphite-derived material, and hexagonal boron nitride dispersed within the polymer material. The polymer material may be referred to as a polymer matrix. At least one of carbon fibers, carbon nanofibers, graphite, a graphite-derived material, and hexagonal boron nitride may be present as filler particles within the polymer matrix.

[0071] The polymer material may be at least one of polyether ether ketone (PEEK) and liquid crystal polymer (LCP) or may include the same. The thermal conductive element may include the polymer material in an amount of 22 percent to 33 percent based on the weight of the thermal conductive element.

[0072] The graphite-derived material may include at least one of expanded graphite and graphite nanoplates. The thermal conductive element may include at least one of carbon fiber, carbon nanofiber, graphite, graphite-derived material, and hexagonal boron nitride in an amount of 62 percent to 69 percent based on the weight of the thermal conductive element.

[0073] The thermal conductive element may further comprise at least one additive dispersed within the polymer material. The at least one additive may comprise carbon black. The thermal conductive element may comprise at least one additive in an amount of 5 percent to 9 percent based on the weight of the thermal conductive element. Advantageously, such an active heating thermal conductive element may be easier to manufacture compared to other external heaters. More specifically, the inventors have observed that due to the thermoplastic properties of the polymer matrix, the composite polymer can be conveniently pliable, allowing for precise and controlled molding. At the same time, by controlling and adjusting the concentration and distribution of conductive filler particles dispersed within the polymer matrix, it is advantageously possible to provide an active thermal conductive element capable of generating sufficient heat by the Joule effect to efficiently heat an aerosol-forming substrate of an aerosol-generating article thermally coupled with the thermal conductive element.

[0074] Without being bound by theory, the inventors have discovered that conductivity can be controlled by adjusting the formulation of the polymer matrix and the degree of dispersion of conductive filler particles within the polymer matrix, and consequently, the amount of heat resisted by the thermal conductive element can be controlled when a voltage is applied to the thermal conductive element. In particular, by adjusting the relative ratio of conductive filler to polymer within the polymer composite, it may be advantageously possible to make the thermal conductive element made of the polymer composite exhibit 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 overall resistance behavior of the thermal conductive element.

[0075] Preferably, the chamber comprises an open first end into which at least a portion of the aerosol generating article can be inserted into the chamber and a closed second end opposite the open first end.

[0076] The aerosol generating device may include at least one projection extending into the chamber from a closed second end of the chamber. Advantageously, the at least one projection may be in contact with an upstream end of an aerosol generating article housed within the chamber, so that the upstream end of the aerosol generating article may be separated 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.

[0077] The aerosol generator may include a housing, and an inductor coil, a resistance heating element, a heat conducting element, a power supply, and a control circuit are disposed within the housing. Preferably, the housing includes an end wall defining a closed second end of a chamber, and at least one protrusion extends from the end wall into the chamber. Preferably, at least one protrusion is formed integrally with the end wall.

[0078] Preferably, at least one protrusion comprises at least three protrusions. Advantageously, providing at least three protrusions can facilitate safe and accurate positioning of an aerosol-generating article within the chamber. Preferably, the chamber has a longitudinal axis defining a first direction in which at least a portion of the aerosol-generating article can be inserted into the chamber, and at least three protrusions are arranged at equal intervals in a circumferential direction centered on the longitudinal axis.

[0079] The aerosol generating device may include a susceptor element. Advantageously, by providing the susceptor element as part of the aerosol generating device, the need to provide the susceptor element in each aerosol generating article can be eliminated. Advantageously, this can reduce the cost of each aerosol generating article.

[0080] As used herein, the term “susceptor element” refers to an element comprising a material capable of converting magnetic field energy into heat. When a susceptor element is placed in an alternating magnetic field, the susceptor is inductively heated. The heating of the susceptor may be due to at least one of hysteresis loss and eddy current induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0081] Preferably, the susceptor element is an elongated susceptor element. Preferably, the elongated susceptor element extends into the chamber from a closed second end of the chamber. Preferably, at least a portion of the elongated susceptor element is disposed inside the inductor coil.

[0082] The susceptor element may be formed of any material capable of being 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 include metal or carbon. Preferably, the susceptor element includes or is composed of a ferromagnetic material, e.g., ferrite iron, a ferromagnetic alloy, e.g., ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrite. Suitable susceptor elements may be or may include aluminum. The susceptor element preferably includes 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 exceeding about 250 degrees Celsius.

[0083] The susceptor element may include a non-metal core in which a metal layer is disposed on a non-metal core. For example, the susceptor element may include one or more metal tracks formed on the outer surface of a ceramic core or a substrate.

[0084] 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 encapsulate the susceptor element. The susceptor element may include a protective coating formed by glass, ceramic, or an inert metal formed on the core of the susceptor material.

[0085] The susceptor element may have any suitable cross-section. For example, the susceptor element may have a square, elliptical, rectangular, triangular, pentagonal, hexagonal, or similar cross-sectional shape. The susceptor element may have a planar or flat cross-sectional shape.

[0086] The susceptor element may be solid, hollow, or porous. Preferably, the susceptor element is solid.

[0087] In an embodiment in which the susceptor element has a planar or flat cross-sectional shape, the susceptor element preferably has a thickness of about 1 millimeter to about 8 millimeters, more preferably about 3 millimeters to about 5 millimeters. The thickness of the susceptor element is measured along the longitudinal direction of the aerosol generator. Preferably, the susceptor element has a width or diameter of about 3 millimeters to about 12 millimeters, more preferably about 4 millimeters to about 10 millimeters, and more preferably about 5 millimeters to about 8 millimeters. The width or diameter of the susceptor element is orthogonal to its thickness.

[0088] In an embodiment 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 millimeters to about 15 millimeters, e.g., about 6 millimeters to about 12 millimeters, or about 8 millimeters to about 10 millimeters. The elongated susceptor element preferably has a width of about 1 millimeter to about 8 millimeters, more preferably about 3 millimeters to about 5 millimeters. The elongated susceptor element may have a thickness of about 0.01 millimeters to about 2 millimeters. If the elongated susceptor element has a constant cross-section, e.g., a circular cross-section, it has a preferred width or diameter of about 1 millimeter to about 5 millimeters.

[0089] Preferably, the thermal conductive element is formed of a first material and the susceptor element is formed of a second material, and the first material is different from the second material. Advantageously, by forming the thermal conductive element and the susceptor element from different materials, 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 can be facilitated.

[0090] Preferably, the inductor coil is positioned so that at least a portion of the aerosol generating article is received within the inductor coil when the aerosol generating article is received within the chamber.

[0091] The inductor coil may be formed from a coiled wire. The wire may comprise an electrically conductive core and a coating of the electrically conductive core. Preferably, the coating is electrically insulating. Advantageously, the electrically insulating coating may prevent an electrical short circuit between adjacent windings of the inductor coil. Advantageously, the electrically insulating coating may electrically isolate the inductor coil from a thermally conductive element. The coating may comprise at least one of a polymer, a ceramic, and a glass. The coating may comprise parylene.

[0092] The inductor coil may be formed from any suitable electrically conductive material. Preferably, the inductor coil is formed from a metal or a metal alloy. The inductor coil may be formed from at least one of copper, a copper alloy, a copper-nickel alloy, tungsten, aluminum, an aluminum alloy, and steel. Suitable steel includes stainless steel, such as 316 stainless steel. In an embodiment in which the inductor coil comprises an electrically conductive core, the metal or a metal alloy may form the electrically conductive core.

[0093] In an embodiment in which the aerosol generating device includes a resistance heating coil, the resistance heating coil may include a metal. The resistance heating coil may include stainless steel. The resistance heating coil may be composed of stainless steel. Advantageously, stainless steel has been found to be a durable material having a resistivity suitable for maximizing the heating of the resistance heating coil through resistance heating. This improves the heating efficiency of the area surrounding the aerosol-forming substrate by the resistance heating coil.

[0094] A resistance heating coil may be formed from a coiled wire. The wire may comprise an electrically conductive core and a coating of the electrically conductive core. Preferably, the coating is electrically insulating. Advantageously, the electrically insulating coating may prevent an electrical short circuit between adjacent windings of the resistance heating coil. Advantageously, the electrically insulating coating may electrically isolate the resistance heating coil from a heat-conducting element. The coating may comprise at least one of a polymer, a ceramic, and a glass. The coating may comprise parylene.

[0095] An inductor coil may contain a material different from a resistance heating coil. An inductor coil may be composed of a material different from a resistance heating coil.

[0096] The power supply unit may be a DC power supply unit. In one embodiment, the power supply unit is a DC power supply unit having a DC supply voltage of about 2.5 volts to about 4.5 volts and a DC supply current of about 1 ampere to about 10 amperes (corresponding to a DC power supply unit of about 2.5 watts to about 45 watts).

[0097] The power supply may be configured to operate at a high frequency. As used herein, the term “high frequency oscillation current” means an oscillation current having a frequency of about 500 kilohertz to about 30 megahertz. The high frequency oscillation 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.

[0098] The aerosol generator includes an inductor coil and a control circuit connected to 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 programmable microprocessor, a microcontroller, an application-specific integrated circuit (ASIC), or other electrical circuit capable of providing control. The control circuit may include additional electronic components. The control circuit may be configured to regulate the current supply to the inductor coil. Current may be supplied to the inductor coil continuously after activation of the aerosol generator, or intermittently, for example, at each puff. The control circuit may advantageously include a DC / AC inverter that may include a Class D or Class E power amplifier.

[0099] Preferably, the aerosol generator is portable. The aerosol generator may have a size similar to a conventional cigar or cigarette. The total length of the aerosol generator may be approximately 30 millimeters to approximately 150 millimeters. The outer diameter of the aerosol generator may be approximately 5 millimeters to approximately 30 millimeters.

[0100] The housing of the aerosol generator may be elongated. The housing may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics, or composite materials containing one or more of these materials, or thermoplastic resins suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK), and polyethylene. Preferably, the material is lightweight and non-brittle.

[0101] The housing may include a mouthpiece. The mouthpiece may include at least one air inlet and at least one air outlet. The mouthpiece may include two or more air inlets. One or more of the air inlets may reduce the temperature of the aerosol before it is delivered to the user and may reduce the concentration of the aerosol before it is delivered to the user.

[0102] Alternatively, a mouthpiece may be provided as part of an aerosol-generating article.

[0103] As used herein, the term "mouthpiece" refers to a part of an aerosol generating device that is placed in the user's mouth so that aerosol generated by the aerosol generating device from an aerosol generating article housed in a chamber of the housing is directly inhaled.

[0104] The aerosol generating device may include a user interface for operating the device, such as a button to initiate heating of the device or a display to indicate the status of the device or an aerosol-forming substrate.

[0105] According to the present disclosure, an aerosol generating system is also provided. The aerosol generating system includes an aerosol generating device of the present disclosure according to any one of the embodiments described herein. The aerosol generating system also includes an aerosol generating article comprising an aerosol forming substrate.

[0106] As used herein, the term "aerosol generating article" refers to an article comprising an aerosol-forming substrate capable of releasing a volatile compound capable of forming an aerosol. The aerosol generating article may be single-use.

[0107] As used herein, the term "aerosol-forming substrate" refers to a substrate composed of or containing an aerosol-forming material capable of releasing a volatile compound upon heating to generate an aerosol.

[0108] The aerosol-generating article may include an article susceptor element. Preferably, the article susceptor element is disposed in direct contact with the aerosol-forming substrate. Preferably, the article susceptor element is an internal susceptor element disposed within the aerosol-forming substrate.

[0109] Preferably, the aerosol generating article is configured such that when the aerosol generating article is inserted into the chamber of the aerosol generating device, at least a portion of the article susceptor element is positioned within the inductor coil.

[0110] The article susceptor element may include any of the aforementioned optional or desirable features for the susceptor element forming part of the aerosol generating device.

[0111] Preferably, the thermal conductive element is formed of a first material and the article susceptor element is formed of a second material, and the first material is different from the second material. Advantageously, by forming the thermal conductive element and the article susceptor element from different materials, 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 can be facilitated.

[0112] Preferably, the aerosol-forming substrate is a solid aerosol-forming substrate. However, the aerosol-forming substrate may include both solid and liquid components. Alternatively, the aerosol-forming substrate may be a liquid aerosol-forming substrate.

[0113] Preferably, the aerosol-forming substrate comprises nicotine. More preferably, the aerosol-forming substrate comprises tobacco. Alternatively or additionally, the aerosol-forming substrate may comprise a non-tobacco-containing aerosol-forming material.

[0114] When the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may include one or more of powders, granules, pellets, shreds, strands, strips, or sheets, for example, including one or more of herb leaves, tobacco leaves, tobacco ribs, puffed tobacco, and homogenized tobacco.

[0115] Optionally, the solid aerosol forming substrate may contain a tobacco or non-tobacco volatile flavor compound that is released upon heating of the solid aerosol forming substrate. The solid aerosol forming substrate may also include one or more capsules containing, for example, additional tobacco volatile flavor compounds or non-tobacco volatile flavor compounds, and such capsules may melt during heating of the solid aerosol forming substrate.

[0116] Optionally, the solid aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The carrier may take the form of powder, granules, pellets, shreds, strands, strips, or sheets. The solid aerosol-forming substrate may be deposited on the surface of the carrier, for example, in the form of sheets, foams, gels, or slurries. The solid aerosol-forming substrate may be deposited on the entire surface of the carrier, or alternatively, may be deposited in a pattern to provide non-uniform flavor delivery during use.

[0117] In a preferred embodiment, the aerosol-forming substrate comprises a homogenized tobacco material. As used herein, the term “homogenized tobacco material” refers to a material formed by aggregating fine tobacco particles.

[0118] Preferably, the aerosol-forming substrate comprises a corrugated sheet of homogenized tobacco material. As used herein, the term “sheet” refers to a laminated element whose width and length are significantly greater than its thickness. As used herein, the term “corrugated” is used to describe a sheet that is flexed, folded, or otherwise compressed or shrunk substantially transversely to the longitudinal axis of the aerosol-generating article. Preferably, the aerosol-forming substrate comprises an aerosol-forming agent. As used herein, the term “aerosol-forming agent” is used to describe any suitable known compound or mixture of compounds that facilitates the formation of an aerosol upon use and substantially withstands thermal degradation at the operating temperature of the aerosol-generating article.

[0119] Suitable aerosol-forming agents 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 mono, di, or triacetate; and aliphatic esters of mono, di, or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol-forming agents are polyhydric alcohols or mixtures thereof, such as propylene glycol, triethylene glycol, and 1,3-butanediol, and most preferably glycerin.

[0120] The aerosol-forming substrate may include a single aerosol-forming agent. Alternatively, the aerosol-forming substrate may include a combination of two or more types of aerosol-forming agents.

[0121] The present invention is defined in the claims. However, a non-limiting, non-comprehensive list of embodiments is provided below. Any one or more of the features of these embodiments may be combined with any one or more features of other embodiments, embodiments, or aspects described herein.

[0122] Example 1: As an aerosol generating device,

[0123] A tubular heat-conducting element comprising a cylindrical inner surface forming a curved surface, wherein the cylindrical inner surface at least partially defines a chamber for accommodating at least a portion of an aerosol-generating article, so that the aerosol-generating article accommodated in the chamber comes into direct contact with the cylindrical inner surface;

[0124] Resistance heating element;

[0125] An inductor coil extending around at least a portion of a thermal conductive element; and

[0126] Includes a power supply unit and a control circuit,

[0127] The power supply unit and control circuit are connected to the resistance heating element and configured to provide current to the resistance heating element so that, when in use, the resistance heating element heats the tubular heat conduction element, and,

[0128] An aerosol generating device in which a power supply unit and a control circuit are connected to an inductor coil and configured to provide alternating current to the inductor coil, so that the inductor coil generates an alternating magnetic field when in use.

[0129] Example 2: An aerosol generating device in which, in Example 1, the tubular heat-conducting element is a resistance heating element, and the power supply unit and control circuit are configured to provide current to the tubular heat-conducting element so that the tubular heat-conducting element is resistance-heated when in use.

[0130] Example 3: An aerosol generating device in Example 1, wherein the resistance heating element is disposed in direct contact with a tubular heat-conducting element, optionally the resistance heating element is in direct contact with the outer surface of the tubular heat-conducting element, and optionally the resistance heating element is at least partially embedded within the tubular heat-conducting element.

[0131] Example 4: The aerosol generating device in Example 1 or Example 3, wherein the resistance heating element is a resistance heating coil, and the resistance heating coil extends around at least a portion of a tubular heat-conducting element.

[0132] Example 5: In any one of the previous examples, the chamber comprises a first end defining an opening for receiving an aerosol generating article and a second end opposite the first end, and the aerosol generating device further comprises a housing defining at least one air inlet and at least one airflow passage extending between the at least one air inlet and the second end of the chamber, wherein the at least one airflow passage is disposed outside the chamber.

[0133] Example 6: The aerosol generating device of Example 5, wherein at least one air inlet is disposed adjacent to an opening, and at least one airflow passage extends between the outer surface of a tubular heat-conducting element and the inner surface of a housing.

[0134] Example 7: The aerosol generating device of Example 5, wherein the chamber defines a longitudinal direction extending between a first end and a second end, at least one air inlet extends through the side wall of the housing, and at least a portion of at least one airflow passage extends perpendicular to the longitudinal direction.

[0135] Example 8: An aerosol generating device in any one of the previous examples, wherein the curved surface defines the circular cross-sectional shape of the chamber.

[0136] Example 9: An aerosol generating device in any one of the previous examples, wherein the tubular heat-conducting element extends in the longitudinal direction and the curved surface extends circumferentially with respect to the longitudinal direction.

[0137] Example 10: An aerosol generating device in which, in Examples 8 and 9, the circular cross-sectional shape of the chamber has a constant diameter in all directions perpendicular to the longitudinal direction.

[0138] Example 11: An aerosol generating device in which, in Example 8, Example 9 or Example 10, the circular cross-sectional shape of the chamber has a roundness of at least 0.999.

[0139] Example 12: An aerosol generating device in which, in any one of the previous examples, the heat-conducting element is formed from at least one of an electrically non-conductive material and a non-conductive heating material.

[0140] Example 13: An aerosol generating device, wherein in any one of the previous examples, the thermal conductive element comprises at least one of a polymer material, a ceramic, and a metal, and optionally the thermal conductive element comprises at least one of an alumina ceramic and a zirconia ceramic.

[0141] Example 14: An aerosol generating device, wherein, in any one of the previous examples, the thermal conductive element comprises at least one of aluminum and paramagnetic steel, and optionally the paramagnetic steel comprises austenitic steel.

[0142] Example 15: An aerosol generating device, wherein, in any one of the previous examples, it further comprises a susceptor element, optionally the thermal conductive element is formed of a first material and the susceptor element is formed of a second material, and the first material is different from the second material.

[0143] Example 16: An aerosol generating device, wherein, in any one of the previous examples, 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 heat-conducting element and an inductor coil during use.

[0144] Example 17: An aerosol generating device, wherein, in any one of the previous examples, the thermal conductive element comprises a polymer material and at least one of carbon fibers, carbon nanofibers, graphite, a graphite-derived material, and hexagonal boron nitride dispersed within the polymer material.

[0145] Example 18: An aerosol generating device according to Example 17, wherein the polymer material comprises at least one of polyether ether ketone (PEEK) and liquid crystal polymer (LCP).

[0146] Example 19: An aerosol generating device in which, in Example 17 or Example 18, the thermal conductive element comprises a polymer material in an amount of 22 percent to 33 percent based on the weight of the thermal conductive element.

[0147] Example 20: An aerosol generating device in Example 17, Example 18 or Example 19, wherein the graphite-derived material comprises at least one of expanded graphite and graphite nanoplates.

[0148] Example 21: An aerosol generating device in any one of Examples 17 to 20, wherein the thermal conductive element comprises at least one of carbon fiber, carbon nanofiber, graphite, graphite-derived material, and hexagonal boron nitride in an amount of 62 percent to 69 percent based on the weight of the thermal conductive element.

[0149] Example 22: An aerosol generating device in any one of Examples 17 to 21, wherein the thermal conductive element further comprises at least one additive dispersed within a polymer material.

[0150] Example 23: An aerosol generating device according to Example 22, wherein at least one additive comprises carbon black.

[0151] Example 24: An aerosol generating device in which, in Example 22 or Example 23, the thermal conductive element comprises at least one additive in an amount of 5 percent to 9 percent based on the weight of the thermal conductive element.

[0152] Example 25: An aerosol generating device, wherein, in any one of the previous examples, the power supply unit and the control circuit are connected to a heat-conducting element and configured to provide current to the heat-conducting element during use to resistively heat the heat-conducting element.

[0153] Example 26: An aerosol generating device, wherein, in any one of the previous examples, the chamber comprises an open first end into which at least a portion of an aerosol generating article can be inserted into the chamber and a closed second end opposite the open first end.

[0154] Example 27: The aerosol generating device of Example 26, further comprising at least one protrusion extending into the chamber from a closed second end of the chamber.

[0155] Example 28: An aerosol generating device according to Example 27, wherein at least one protrusion comprises at least three protrusions.

[0156] Example 29: The aerosol generating device of Example 28, wherein the chamber has a longitudinal axis defining a first direction into which at least a portion of an aerosol generating article can be inserted into the chamber, and at least three protrusions are arranged at equal intervals in a circumferential direction centered on the longitudinal axis.

[0157] Example 30: An aerosol generating device, wherein, in any one of the previous examples, it further comprises a housing, and the inductor coil, the thermal conductive element, the power supply, and the control circuit are disposed within the housing.

[0158] Example 31: An aerosol generating device in any combination of Example 30 and Examples 26 to 29, wherein the housing comprises a terminal wall defining a closed second end of the chamber, and at least one protrusion extending from the terminal wall into the chamber.

[0159] Example 32: An aerosol generating device according to Example 31, wherein at least one protrusion is formed integrally with the end wall.

[0160] Example 33: An aerosol generating device comprising, in any one of Examples 26 to 32, a slender susceptor element extending into the chamber from a closed second end of the chamber.

[0161] Example 34: An aerosol generating device according to Example 33, wherein at least a portion of the slender susceptor element is disposed inside an inductor coil.

[0162] Example 35: As an aerosol generating system,

[0163] Aerosol generating device according to any one of the prior embodiments; and

[0164] An aerosol generating system comprising an aerosol generating article comprising an aerosol forming substrate.

[0165] Example 36: The aerosol generating system of Example 35, wherein the aerosol generating article is configured such that when the aerosol generating article is inserted into a chamber, at least a portion of the aerosol forming substrate is disposed within a heat-conducting element.

[0166] Example 37: The aerosol generating system of Example 35 or Example 36, wherein the aerosol generating article further comprises an article susceptor element.

[0167] Example 38: The aerosol generating system of Example 37, wherein the aerosol generating article is configured such that when the aerosol generating article is inserted into a chamber, at least a portion of the article susceptor element is disposed within an inductor coil.

[0168] Example 39: In Example 37 or Example 38, the thermal conductive element is formed of a first material, and the article susceptor element is formed of a second material, wherein the first material is different from the second material, an aerosol generating system. Brief explanation of the drawing

[0169] The present invention will be described in more detail merely by way of example with reference to the attached drawings: FIG. 1 illustrates a side cross-sectional view of an aerosol generating device according to a first embodiment of the present invention; FIG. 2 shows an axial cross-sectional view taken along line 1-1 of the aerosol generator of FIG. 1; FIG. 3 shows a side cross-sectional view of an aerosol generating system including the aerosol generating device of FIG. 1; FIG. 4 illustrates a perspective view of a heat-conducting element and coil arrangement of an aerosol generating device according to a second embodiment of the present invention; FIG. 5 shows a side cross-sectional view of an aerosol generator including the heat conduction element and coil arrangement of FIG. 4; FIG. 6 illustrates a partial side cross-sectional view of an aerosol generating device according to a third embodiment of the present invention; FIG. 7 illustrates a side cross-sectional view of an aerosol generating system including the aerosol generating device of FIG. 6; FIG. 8 illustrates a partial side cross-sectional view of an aerosol generating device according to a fourth embodiment of the present invention; and FIG. 9 shows a side cross-sectional view of an aerosol generating system including the aerosol generating device of FIG. 8. Specific details for implementing the invention

[0170] FIGS. 1 and 2 illustrate an aerosol generating device (10) according to a first embodiment of the present invention. The aerosol generating device (10) includes a housing (12) that partially defines a chamber (16) for receiving a portion of an aerosol generating article. The chamber (16) includes a first end (18) through which an aerosol generating article can be inserted into the chamber (16), and a second end (20) located opposite the first end (18).

[0171] The aerosol generating device (10) also includes a heat-conducting element (28) comprising an outer surface (21) and an inner surface (23). The inner surface (23) is cylindrical in shape and has no grooves, channels, or other discontinuities. Thus, the inner surface (23) is smooth and forms a curved surface that at least partially defines the cylindrical wall (22) of the chamber (16) extending between the first end (18) and the second end (20). The heat-conducting element (28) is positioned so that when an aerosol generating article is inserted into the chamber (16), the aerosol generating article is received within the heat-conducting element (28) and comes into direct contact with the cylindrical inner surface (23) of the heat-conducting element (28).

[0172] An inductor coil (24) comprising a plurality of windings (26) extends around the outer surface of a heat-conducting element (28). The inductor coil (24) and the heat-conducting element (28) are arranged concentrically around the central axis (36) of the aerosol generator (10).

[0173] As illustrated in FIG. 1, the housing (12) defines a plurality of air inlets (25) extending through the outer surface of the housing (12) and airflow passages (27) extending from each air inlet (25). The plurality of airflow passages (27) are combined into a single common airflow passage (30) that is fluidly connected to the second end (20) of the chamber (16). In the embodiment illustrated in FIG. 1, the housing (12) defines two air inlets (25) and two airflow passages (27) positioned on opposite sides of the housing (12). Those skilled in the art will understand that the housing (12) may define more or fewer air inlets (25) and airflow passages (27), and that the arrangement of the air inlets (25) and airflow passages (27) around the housing (12) may be changed.

[0174] The housing (12) also defines a plurality of protrusions (38) extending into the chamber (16) from the second end (20) of the chamber (16). As described below, the plurality of protrusions (38) function to maintain a gap between the end of the aerosol generating article and the second end (20) of the chamber (16) when the aerosol generating article is fully inserted into the chamber (16). In the embodiment illustrated in FIGS. 1 and 2, the housing (12) defines three protrusions (38) spaced equidistantly around the central axis (36) of the aerosol generating device (10). Those skilled in the art will understand that the housing (12) may define more or fewer protrusions (38) and that the arrangement of the protrusions (38) at the closed end (20) of the chamber (16) may be changed.

[0175] The aerosol generator (10) also includes a control circuit (40) and a power supply unit (42) connected to an inductor coil (24). The control circuit (40) is configured to generate an alternating magnetic field by supplying alternating current from the power supply unit (42) to the inductor coil (24). The control circuit (40) is also configured to provide direct current from the power supply unit (42) to a heat-conducting element (28). In this way, the heat-conducting element (28) functions as a resistance heating element.

[0176] FIG. 3 shows a cross-sectional view of an aerosol generating system (100) including the aerosol generating device (10) of FIG. 1 and an aerosol generating article (102).

[0177] The aerosol generating article (102) comprises an aerosol forming substrate (104) in the shape 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 a chamber (16) such that the aerosol forming substrate (104) and the susceptor element (114) are disposed within a heat conduction element (28) and an inductor coil (24). A control circuit (40) supplies an alternating current from a power supply (42) to the inductor coil (24) to generate an alternating magnetic field that inductively heats the susceptor element (114) which generates the aerosol by heating the aerosol forming substrate (104). Additionally, heat generated in the inductor coil (24) itself by resistance loss in the inductor coil (24) can be conducted from the inductor coil (24) to the aerosol-forming substrate (104) by the heat-conducting element (28). The control circuit (40) also provides direct current from the power supply (42) to the heat-conducting element (28) to resistance-heat the heat-conducting element (28). Advantageously, direct contact between the cylindrical inner surface (23) of the heat-conducting element (28) and the aerosol-generating article (102) facilitates the transfer of heat generated by resistance heating from the heat-conducting element (28) to the aerosol-generating article (102). Advantageously, the smooth curved surface formed by the cylindrical inner surface (23) of the heat-conducting element (28) maximizes the contact area between the heat-conducting element (23) and the aerosol generating article (102), which increases or maximizes heat transfer from the heat-conducting element (23) to the aerosol generating article (102). Advantageously, external heating provided by the resistance-heating heat-conducting element (23) and internal heating provided by the induction-heating susceptor element (114) can provide uniform heating of the aerosol generating substrate (104).

[0178] The airflow passing through the aerosol generating system (100) during use is illustrated by the dashed line (116) in FIG. 3. When a user inhales the mouthpiece (110) of the aerosol generating item (102), negative pressure is generated in the chamber (16). The negative pressure draws air into the aerosol generating device (10) through the air inlet (25). The air entering through the air inlet (25) flows along the airflow passage (27), enters the common airflow passage (30), and reaches the second end (20) of the chamber (16). The air entering through the second end (20) of the chamber (16) enters the aerosol generating item (102) through the aerosol forming material (104). Airflow to the aerosol generating article (102) is facilitated by a gap maintained between the upstream end of the aerosol generating article (102) and the second 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 along with the airflow. Then, the aerosol flows along the length of the aerosol generating article (102) and reaches the user through the mouthpiece (110).

[0179] FIG. 4 illustrates a perspective view of a heat-conducting element and coil arrangement of an aerosol generating device according to a second embodiment of the present invention. FIG. 5 illustrates a cross-sectional view of an aerosol generating device (110) including the heat-conducting element and coil arrangement of FIG. 4. The embodiments of FIG. 4 and FIG. 5 share features with the embodiments of FIG. 1 to FIG. 3, and similar reference numerals are used to indicate similar parts.

[0180] The embodiment of FIG. 4 includes an inductor coil (124) comprising a tubular heat-conducting element (28) identical to the embodiment of FIG. 1 and a plurality of windings (126) extending around the outer surface (21) of the heat-conducting element (28), so that the plurality of windings (126) are in direct contact with the outer surface (21) of the heat-conducting element (28). The configuration of FIG. 4 also includes a resistance heating coil (133) having a plurality of windings (135) extending around the outer surface (21) of the heat-conducting element (28), so that the plurality of windings (135) are in direct contact with the outer surface (21) of the heat-conducting element (28). The resistance heating coil (133) is wound together with the inductor coil (124) around the outer surface (12) of the heat-conducting element (28). During use, the control circuit (40) supplies alternating current from the power supply unit (42) to the inductor coil (124) to generate an alternating magnetic field that inductively heats the susceptor element of the aerosol generating article, which can provide internal heating of the aerosol forming substrate. For example, the aerosol generating device (100) of FIG. 5 can be used with the aerosol generating article (102) of FIG. 3. During use, the control circuit (40) also supplies direct current from the power supply unit (42) to the resistance heating coil (133) to resistance heat the resistance heating coil (133). The heat generated by the resistance heating coil (133) is conducted to the aerosol generating article through the tubular heat conduction element (28) to provide external heating of the aerosol forming substrate.

[0181] FIG. 6 illustrates a partial cross-sectional view of a modified example of the aerosol generating device (110) of FIG. 5. The embodiment of FIG. 6 shares features with the embodiments of FIG. 1 and FIG. 5, and the same reference numerals are used to refer to the same parts.

[0182] The embodiment of FIG. 6 includes the same tubular heat conduction element (28) and inductor coil (24) as the embodiment of FIG. 1, and the same resistance heating coil (133) as the embodiment of FIG. 5. The embodiment of FIG. 6 has an alternative airflow configuration defined by a housing (212). Specifically, the housing (212) defines a plurality of air inlets (225) extending through the inner surface of the chamber (16) and airflow passages (227) extending from each air inlet (225). The airflow passages (227) extend to the outside of the chamber (16) so that airflow through the airflow passages (227) flows between the inductor coil (24) and the resistance heating coil (133). Advantageously, heat generated by resistance heating of the inductor coil (24) and the resistance heating coil (133) during use can provide preheating of the airflow passing through the airflow passages (227). Multiple airflow passages (227) are combined into a single common airflow passage (30) that is fluidly connected to the second end (20) of the chamber (16). In the embodiment illustrated in FIG. 6, the housing (212) defines two air inlets (225) and two airflow passages (227) positioned opposite the chamber (16). Those skilled in the art will understand that the housing (212) may define more or fewer air inlets (225) and airflow passages (227), and that the arrangement of the air inlets (225) and airflow passages (227) around the chamber (16) may be changed.

[0183] FIG. 7 illustrates a cross-sectional view of an aerosol generating system (300) comprising the aerosol generating device (210) of FIG. 6 and an aerosol generating article (302). The aerosol generating article (302) is similar to the aerosol generating article (102) described with reference to FIG. 3, and similar reference numbers are used to indicate similar parts. The aerosol generating article (302) differs in that a forward plug (315) of cellulose acetate is added and placed upstream of the aerosol forming substrate (104).

[0184] The airflow passing through the aerosol generating system (300) during use is illustrated by the dashed line (316) in FIG. 7. When a user inhales the mouthpiece (110) of the aerosol generating item (302), negative pressure is generated in the chamber (16). The negative pressure draws air into the aerosol generating device (210) through the air inlet (225). In this regard, the housing (212) is spaced apart from the aerosol generating item (302) at the first end (18) of the chamber (16) so that air can flow into the air inlet (225). The air flowing into the air inlet (225) flows along the airflow passage (227) outside the chamber (16), enters the common airflow passage (30), and reaches the second end (20) of the chamber (16). Air introduced into the second end (20) of the chamber (16) enters the aerosol generating article (302) through the front plug (315). The airflow into the aerosol generating article (302) is facilitated by a gap maintained between the upstream end of the aerosol generating article (302) and the second 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 along with the airflow. Then, the aerosol flows along the length of the aerosol generating article (302) and reaches the user through the mouthpiece (110).

[0185] FIG. 8 illustrates a partial cross-sectional view of an alternative configuration for the aerosol generator of FIG. 6. In this regard, the aerosol generator (410) of FIG. 8 is similar to the aerosol generator (210) of FIG. 6, and the similar parts are indicated by similar reference numbers.

[0186] The aerosol generating device (410) of FIG. 8 differs in that it has an additional elongated susceptor element (411) extending from the second end (20) of the chamber (16) into the chamber (16). When the aerosol generating article is inserted into the chamber (16), the elongated susceptor element (411) is received inside the aerosol forming substrate of the aerosol generating article. During use, the control circuit (40) supplies an alternating current from the power supply unit (42) to the inductor coil (24) to generate an alternating magnetic field that inductively heats the elongated susceptor element (411) in order to heat the aerosol forming substrate.

[0187] To accommodate the susceptor element (411), the aerosol generator (410) does not include a common airflow passage at the second end (20) of the chamber (16). Instead, each airflow passage (427) flows through the side wall (429) of the chamber (16) and delivers airflow into the chamber (16) upstream of the second end (20).

[0188] FIG. 9 illustrates a cross-sectional view of an aerosol generating system (500) comprising the aerosol generating device (410) of FIG. 8 and an aerosol generating article (502). The aerosol generating article (502) is similar to the aerosol generating article (302) described with reference to FIG. 7, and similar reference numbers are used to indicate similar parts. The aerosol generating article (502) differs in that it does not have a susceptor element within the aerosol forming substrate (104).

[0189] The airflow passing through the aerosol generating system (500) during use is illustrated by the dashed line (516) in FIG. 9. When a user inhales the mouthpiece (110) of the aerosol generating item (502), negative pressure is generated in the chamber (16). The negative pressure draws air into the aerosol generating device (410) through the air inlet (225). In this regard, the housing (212) is spaced apart from the aerosol generating item (502) at the first end (18) of the chamber (16) so that air can enter the air inlet (225). The air entering the air inlet (225) flows along the airflow passage (227) outside the chamber (16) and enters the chamber (16) upstream of the tubular heat conduction element (28) and downstream of the second end (20) of the chamber (16). Then, air flowing into the chamber (16) from the airflow passage (227) flows into the front plug (315) through the outer wrapper (112) and enters the aerosol generating article (502). The airflow passing through the outer wrapper (112) can be facilitated by providing the outer wrapper (112) with an increased porosity area extending around at least one of the front plug (315) and the aerosol forming substrate (104). As the airflow passes through the aerosol forming substrate (104), the aerosol generated by the heating of the aerosol forming substrate (104) is carried along with the airflow. Then, the aerosol flows along the length of the aerosol generating article (502) and reaches the user through the mouthpiece (110).

[0190] Those skilled in the art will understand that the slender susceptor element (411) may be combined with other embodiments of FIGS. 1 through 7. For example, the aerosol generator (210) of FIG. 6 may be modified to include a plurality of slender susceptor elements arranged around a common airflow passage (30). Alternatively, the aerosol generator (210) of FIG. 6 may be modified to include a single slender susceptor element and to replace the common airflow passage (30) with a plurality of openings at a second end (20) of the chamber (16), wherein the plurality of openings are arranged around the single slender susceptor element and each airflow passage (27) transmits airflow to the second end (20) of the chamber (16) through one of the openings. A similar modification may be made to the aerosol generator (10) of FIG. 1 to accommodate a single slender susceptor element or a plurality of slender susceptor elements. Additionally, an aerosol generating device including one or more elongated susceptor elements extending into the chamber (16) may also include the coil arrangement of FIG. 4.

Claims

Claim 1 An aerosol generating device comprising: a tubular heat-conducting element including a cylindrical inner surface forming a curved surface, wherein the cylindrical inner surface partially defines a chamber for accommodating at least a portion of an aerosol generating article, so that the aerosol generating article accommodated in the chamber comes into direct contact with the cylindrical inner surface; a resistance heating element formed separately from the heat-conducting element; an inductor coil extending around at least a portion of the heat-conducting element; and a power supply unit and a control circuit, wherein the power supply unit and the control circuit are connected to the resistance heating element and configured to provide current to the resistance heating element so that when in use, the resistance heating element heats the tubular heat-conducting element, and the power supply unit and the control circuit are connected to the inductor coil and configured to provide alternating current to the inductor coil so that when in use, the inductor coil generates an alternating magnetic field. Claim 2 An aerosol generating device according to claim 1, wherein the resistance heating element extends around at least a portion of the tubular heat conducting element. Claim 3 An aerosol generating device according to claim 1, wherein the resistance heating element is disposed in direct contact with the tubular heat conducting element, optionally the resistance heating element is in direct contact with the outer surface of the tubular heat conducting element, and optionally the resistance heating element is at least partially embedded within the tubular heat conducting element. Claim 4 An aerosol generating device according to claim 1, 2, or 3, wherein the resistance heating element is a resistance heating coil, and the resistance heating coil extends around at least a portion of the tubular heat conducting element. Claim 5 An aerosol generating device according to any one of claims 1 to 4, wherein the chamber comprises a first end defining an opening for receiving an aerosol generating article and a second end opposite the first end, and the aerosol generating device further comprises a housing defining at least one air inlet and at least one airflow passage extending between the at least one air inlet and the second end of the chamber, wherein the at least one airflow passage is disposed outside the chamber. Claim 6 An aerosol generating device according to claim 5, wherein the at least one air inlet is disposed adjacent to the opening, and the at least one airflow passage extends between the outer surface of the tubular heat-conducting element and the inner surface of the housing. Claim 7 An aerosol generating device according to claim 5, wherein the chamber defines a longitudinal direction extending between the first end and the second end, the at least one air inlet extends through the side wall of the housing, and at least a portion of the at least one airflow passage extends perpendicular to the longitudinal direction. Claim 8 An aerosol generating device according to any one of claims 1 to 7, wherein the curved surface defines the circular cross-sectional shape of the chamber. Claim 9 An aerosol generating device according to any one of claims 1 to 8, wherein the tubular heat-conducting element extends in the longitudinal direction and the curved surface extends in the circumferential direction centered on the longitudinal direction. Claim 10 An aerosol generating device according to claims 8 and 9, wherein the circular cross-sectional shape of the chamber has a constant diameter in all directions perpendicular to the longitudinal direction. Claim 11 An aerosol generating device according to any one of claims 1 to 10, wherein the heat-conducting element is formed from at least one of an electrically non-conductive material and a non-conductive heating material. Claim 12 An aerosol generating device according to any one of claims 1 to 11, wherein the heat-conducting element comprises at least one of a polymer material, a ceramic, and a metal, and optionally the heat-conducting element comprises at least one of an alumina ceramic and a zirconia ceramic. Claim 13 An aerosol generating device according to any one of claims 1 to 12, wherein the heat-conducting element comprises at least one of aluminum and paramagnetic steel, and optionally the paramagnetic steel comprises austenitic steel. Claim 14 An aerosol generating device according to any one of claims 1 to 13, further comprising a susceptor element, wherein optionally the heat-conducting element is formed of a first material and the susceptor element is formed of a second material, and the first material is different from the second material. Claim 15 An aerosol generating system comprising: an aerosol generating device according to any one of claims 1 to 14; and an aerosol generating article comprising an aerosol forming substrate.

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