Aerosol generating device and aerosol generating system

Abstract

The aerosol generating device (10) includes a controller (24) and an induction heating device (46) configured to heat an aerosol-generating substrate (102) to generate an aerosol to be inhaled. The induction heating device (46) includes an induction coil (48) including at least a plurality of first coil strands (62) and a plurality of second coil strands (64), and the controller (24) is configured to control the induction heating device (46) to supply alternating current to the plurality of first coil strands (62) to generate a first electromagnetic field having a first frequency, and to supply alternating current to the plurality of second coil strands (64) to generate a second electromagnetic field having a second frequency different from the first frequency. An aerosol generating system 1 including the aerosol generating device (10) and the aerosol-generating substrate (102) is also described.

Description

Technical Field

[0001] The present disclosure generally relates to aerosol generating devices, and more particularly to aerosol generating devices for heating an aerosol generating substrate to generate an aerosol for inhalation by a user. Embodiments of the present disclosure also relate to an aerosol generating system including an aerosol generating device and an aerosol generating substrate, and a method of using the aerosol generating system to generate an inhaled aerosol. The present disclosure is particularly applicable to portable (handheld) aerosol generating devices. Such devices heat an aerosol generating substrate, such as tobacco or other suitable material, not by combustion but by conduction, convection and / or radiation to generate an aerosol for inhalation by the user. The present disclosure particularly relates to inductively heated aerosol generating devices and / or systems.

Background Art

[0002] In recent years, the popularity and use of risk reduction devices or risk modification devices (also known as aerosol generating devices, or vapor generating devices, or personal vaporizers) has grown rapidly as an alternative to the use of conventional tobacco products. A variety of devices and systems are available for heating or warming an aerosol generating substance to generate an aerosol for inhalation by a user.

[0003] Generally available risk reduction devices or risk modification devices are substrate heated aerosol generating devices, i.e., so-called non-combustion heated devices. This type of device generates an aerosol or vapor by heating an aerosol generating substrate typically to a temperature in the range of 150°C to 300°C. By heating the aerosol generating substrate to a temperature within this range without burning or combusting the aerosol generating substrate, vapor is generated, which typically cools and condenses to form an aerosol inhaled by the user of the device.

[0004] Currently available aerosol generating devices can heat an aerosol generating substrate using one of several different methods. One such method involves providing an aerosol generating device that employs an induction heating system. In such a device, an induction coil and an induction-heatable susceptor are provided within the device to heat the aerosol generating substrate. When the user operates the device, electrical energy is supplied to the induction coil, which then generates an alternating current electromagnetic field. The susceptor couples with this electromagnetic field to generate heat, which is transferred to the aerosol generating substrate by one or more means, such as conduction, radiation, and convection, and as the aerosol generating substrate heats up, an aerosol is generated. [Overview of the project] [Problems that the invention aims to solve]

[0005] Generally, it is desirable to control the heat distribution within the aerosol generating substrate to ensure that an aerosol with acceptable properties for user inhalation is generated throughout the usage period (also known as a smoking session). An object of the embodiments of this disclosure is to provide an improved user experience in which the properties of the generated aerosol are optimized by more precise control of the heat distribution within the aerosol generating substrate. [Means for solving the problem]

[0006] According to a first aspect of this disclosure, an aerosol generating device, Controller and An induction heating device configured to generate an inhaled aerosol by heating an aerosol generating substrate, comprising an induction coil including at least a plurality of first coil strands and a plurality of second coil strands, An aerosol generating device is provided, in which the controller is configured to control an induction heating device to supply alternating current to a plurality of first coil strands to generate a first electromagnetic field having a first frequency, and to supply alternating current to a plurality of second coil strands to generate a second electromagnetic field having a second frequency different from the first frequency.

[0007] An aerosol generating device is configured to generate heated vapor by heating an aerosol generating substrate without burning it, thereby volatilizing at least one component of the aerosol generating substrate. This vapor is then cooled and condensed to form an aerosol for the user of the aerosol generating device to inhale. Aerosol generating devices are typically handheld, portable devices.

[0008] Generally speaking, vapor is a substance that is in the gaseous phase at temperatures below its critical temperature, meaning that vapor can be condensed into a liquid by increasing the pressure without lowering the temperature, while aerosol is fine solid particles or droplets suspended in air or another gas. However, it should be noted that in this specification, the terms “aerosol” and “vapor” may be used synonymously, particularly in reference to the form of an inhalable medium generated for inhalation by the user.

[0009] By generating first and second electromagnetic fields having different first and second frequencies, the disclosure enables careful control of the heat distribution within the aerosol generating substrate, for example, by allowing the first electromagnetic field to cause preferential heating of a first inductively heatable susceptor and the second electromagnetic field to cause preferential heating of a second inductively heatable susceptor. Thus, selective (or "zone-divided") heating of the aerosol generating substrate can be achieved. The use of a single induction coil including a plurality of first coil strands for generating the first electromagnetic field and a plurality of second coil strands for generating the second electromagnetic field provides an effective solution for generating the first and second electromagnetic fields and ensures that the aerosol generating device has a compact design.

[0010] The optional features are described below. These can be applied individually or in any combination with any aspect of this disclosure.

[0011] The induction coil may include a first coil portion on which a plurality of first coil strands may be arranged, and a second coil portion on which a plurality of second coil strands may be arranged. The induction coil may include a peripheral portion defining the cross-sectional coil sheath, and the first and second coil portions may be arranged within the cross-sectional coil sheath. By providing the first and second coil portions, the plurality of first coil strands and the plurality of second coil strands are reliably separated from each other within the cross-sectional coil sheath.

[0012] The induction coil may include an outer insulator that surrounds both the first and second coil portions and can define the coil periphery.

[0013] The induction coil has a first end and a second end, and both the first coil strand and the second coil strand can extend from the first end to the second end.

[0014] The first and second coil portions can be electrically insulated from each other. This ensures that there is no electrical contact between the multiple first coil strands of the first coil portion and the multiple second coil strands of the second coil portion.

[0015] A plurality of first coil strands may have a first cross-section, and a plurality of second coil strands may have a second cross-section that may differ from the first cross-section. The different first and second cross-sections facilitate the generation of first and second electromagnetic fields having different first and second frequencies. For example, a plurality of first coil strands and a plurality of second coil strands may differ from each other in one or more of their cross-sectional shapes and cross-sectional areas.

[0016] The alternating current supplied to the first coil strand includes the first alternating current, and the alternating current supplied to the second coil strand may include the second alternating current. The first alternating current may be different from the second alternating current. The first coil strand may be the same as the second coil strand (e.g., in cross-section, diameter and material). Alternatively, the first coil strand may be different from the second coil strand (e.g., in cross-section, diameter and / or material as discussed above).

[0017] The controller may be configured to sequentially supply alternating current to a plurality of first coil strands and a plurality of second coil strands to sequentially generate a first electromagnetic field and a second electromagnetic field. Therefore, the first and second electromagnetic fields are not generated simultaneously but at different times. This allows for continuous heating of different regions or parts of the aerosol generating substrate, and convenient control of the heat distribution within the aerosol generating substrate, particularly selective (or "zone-divided") heating.

[0018] The controller may be configured to generate a first electromagnetic field over a first period by supplying a (first) alternating current to a plurality of first coil strands, and then to generate a second electromagnetic field over a second period following the first period by supplying a (second) alternating current to a plurality of second coil strands. The first electromagnetic field may cause preferential heating of a first inductively heated susceptor during the first period, and the second electromagnetic field may cause preferential heating of a second inductively heated susceptor during the second period. Thus, the first inductively heated susceptor may be heated to a higher temperature than the second inductively heated susceptor during the first period, while the second inductively heated susceptor may be heated to a higher temperature than the first inductively heated susceptor during the second period. Furthermore, this provides a controlled heat distribution within the aerosol-generating substrate, and in particular, offers selective (or "zone-divided") heating.

[0019] The aerosol generating device may include a heating chamber capable of defining a heating zone for receiving at least a portion of the aerosol generating substrate. An induction coil may be positioned adjacent to the heating chamber to generate first and second electromagnetic fields within the heating zone. Thus, the aerosol generating substrate can be efficiently heated when placed in the heating zone defined by the heating chamber.

[0020] A first electromagnetic field may be adapted to heat a first inductively heatable susceptor having a first resonant frequency, and a second electromagnetic field may be adapted to heat a second inductively heatable susceptor having a second resonant frequency different from that of the first. Thus, the first electromagnetic field causes preferential heating of the first inductively heatable susceptor, and the second electromagnetic field causes preferential heating of the second inductively heatable susceptor. By using different resonant frequencies, selective (or "zone-divided") heating of the aerosol-generating substrate can be achieved.

[0021] By using different resonant frequencies, selective (or "zone-divided") heating of an aerosol-generating substrate becomes possible by controlling the induction heating device so that multiple first coil strands generate a first electromagnetic field having a first frequency substantially equal to the first resonant frequency of a first induction-heatable susceptor, and multiple second coil strands generate a second electromagnetic field having a second frequency substantially equal to the second resonant frequency of a second induction-heatable susceptor. Heat is generated in a particular susceptor (first or second susceptor) by generating an electromagnetic field (first or second electromagnetic field) having a frequency (first or second frequency) substantially equal to the resonant frequency (first or second resonant frequency) of that susceptor. This may also generate an amount of heat in one or more other susceptors (i.e., susceptors with resonant frequencies not substantially equal to the frequency of the generated electromagnetic field) that is typically less than, and may be zero or substantially zero, the amount of heat generated by the particular susceptor. Therefore, any selective heating of a particular susceptor should not be interpreted as meaning that other susceptors are not heated at all, and selective heating of a particular susceptor usually means only that it is primarily involved in the release of aerosols from aerosol-generating substrates adjacent to that particular susceptor. The term “preferential heating” is used throughout this specification to define this type of heating.

[0022] The aerosol generating device includes a first induction-heatable susceptor and a second induction-heatable susceptor. The first and second induction-heatable susceptors provide rapid and controlled heating of the aerosol generating substrate while simultaneously maximizing energy efficiency. By providing the first and second induction-heatable susceptors as part of the aerosol generating device, rather than providing the aerosol generating substrate as part of the aerosol generating article, the structure and manufacturing of the aerosol generating article can be simplified.

[0023] The first and second inductively heatable susceptors are arranged around the heating chamber within the heating zone and can respectively define a first region and a second region within the heating zone. The induction coil can extend spirally around the heating chamber. Thus, selective (or "zone-divided") heating of the aerosol-generating substrate can be achieved in the first and second regions. For example, a first portion of the aerosol-generating substrate can be disposed in the first region and heated within the first region by the first inductively heatable susceptor, and a second portion of the aerosol-generating substrate can be disposed in the second region and heated within the second region by the second inductively heatable susceptor. By providing an induction coil that extends spirally around the heating chamber, reliable heating of the first and second inductively heatable susceptors by the corresponding first and second electromagnetic fields can be ensured.

[0024] The induction coil can include a litz wire or a litz cable. However, it should be understood that other materials can also be used.

[0025] The induction coil can be arranged to operate with a varying electromagnetic field having a magnetic flux density of from about 20 mT to about 2.0 T (highest density point) during use.

[0026] The heating chamber can be substantially tubular, and the first and second inductively heatable susceptors can be spaced apart around the periphery of the substantially tubular heating chamber. The heating chamber can be substantially cylindrical, and the first and second inductively heatable susceptors can be circumferentially spaced apart around the substantially cylindrical heating chamber. Thus, the heating chamber can be configured to receive a substantially cylindrical aerosol-generating substrate, and in many cases, the aerosol-generating substrate in the form of an aerosol-generating article is packaged and sold in a cylindrical shape, so this cylindrical aerosol-generating substrate can be advantageous.

[0027] The heating chamber may have a longitudinal axis defining a longitudinal direction. Each of the first and second inductively heatable susceptors may be elongated in the longitudinal direction of the heating chamber. Each of the first and second inductively heatable susceptors may have a length and a width, and in one embodiment, the length may be at least five times the width. The elongated first and second inductively heatable susceptors are efficiently heated in the presence of the first and second electromagnetic fields, and due to their elongated shape, it is ensured that the aerosol generating substrate is heated rapidly and uniformly along the length direction. Thereby, the energy efficiency of the aerosol generating device is maximized.

[0028] The heating chamber may comprise a substantially non-conductive and non-magnetic material. For example, the heating chamber may comprise a heat-resistant plastic material such as polyetheretherketone (PEEK). During operation of the aerosol generating device, the heating chamber itself is not heated by the inductive heating device, so as to maximize the energy input to the first and second inductively heatable susceptors. This thus ensures the maximization of the energy efficiency of the device. Since the device remains cold to the touch, the maximization of user comfort is ensured.

[0029] The first and second inductively heatable susceptors may comprise a metal. The metal is typically selected from the group consisting of stainless steel and carbon steel. However, the first and second inductively heatable susceptors may comprise any suitable material including, but not limited to, one or more of aluminum, iron, nickel, stainless steel, carbon steel and their alloys, such as nickel-chrome or nickel-copper. When a first or second electromagnetic field is applied in the vicinity of the susceptor, the corresponding first or second inductively heatable susceptor generates heat due to the energy conversion from electromagnetic to thermal caused by eddy currents and magnetic hysteresis losses.

[0030] The aerosol generating device may include a power supply, and the controller may include a control circuit. The power supply and control circuit may be configured to operate at high frequencies. The power supply and control circuit may be configured to operate at frequencies of approximately 80 kHz to 1 MHz, optionally approximately 150 kHz to 250 kHz, and optionally approximately 200 kHz. Depending on the type of inductively heated susceptor used, the power supply and control circuit may be configured to operate at even higher frequencies, such as in the MHz range. The power supply and control circuit may be configured to operate at multiple frequencies (e.g., at least two frequencies).

[0031] According to a second aspect of this disclosure, an aerosol generating system, Aerosol generating substrate and An aerosol generating device as defined above for generating an inhaled aerosol by heating an aerosol generating substrate, An aerosol generation system including the above is provided.

[0032] The aerosol-generating substrate may include any type of solid or semi-solid material. Examples of aerosol-generating solids include, for example, powders, granules, pellets, shredded, stranded, particles, gels, strips, loose leaves, cut fillers, porous materials, foamed materials, or sheets. The aerosol-generating substrate may include plant-derived materials, particularly tobacco. Advantageously, the aerosol-generating substrate may include reconstituted tobacco, for example, reconstituted tobacco comprising tobacco and any one or more of cellulose fibers, tobacco stem fibers, and inorganic fillers (such as CaCO3).

[0033] Therefore, aerosol generating devices may be referred to as "heated tobacco devices," "heated non-combustion tobacco devices," or "tobacco product vaporization devices," and are interpreted as devices suitable for achieving these effects. The features disclosed herein are equally applicable to devices designed to vaporize any aerosol generating substrate.

[0034] The aerosol-generating substrate may form part of the aerosol-generating article and may be surrounded by a paper wrapper.

[0035] The aerosol generating article may be formed substantially in the shape of a stick and may be roughly similar to a cigarette having a tubular region with an aerosol generating substrate arranged in a preferred form. The aerosol generating article may include a filter segment at its proximal end, for example, containing cellulose acetate fibers. The filter segment may constitute a mouthpiece filter and may be coaxially aligned with the aerosol generating substrate. Some designs may also include one or more vapor collection regions, cooling regions, and other structures. For example, the aerosol generating article may include at least one tubular segment upstream of the filter segment. The tubular segment may function as a vapor cooling region. The vapor cooling region may advantageously allow heated vapor generated by heating the aerosol generating substrate to cool and condense to form an aerosol with properties suitable for user inhalation, for example, through the filter segment.

[0036] The aerosol generating substrate may contain an aerosol-forming agent. Examples of aerosol-forming agents include polyhydric alcohols such as glycerin or propylene glycol, and mixtures thereof. Typically, the aerosol generating substrate may contain an aerosol-forming agent content of about 5% to about 50% on a dry weight basis. In some embodiments, the aerosol generating substrate may contain an aerosol-forming agent content of about 10% to about 20%, and optionally about 15%, on a dry weight basis.

[0037] When heated by a first or second induction-heatable susceptor, the aerosol-generating substrate may release volatile compounds. These volatile compounds may include nicotine or flavoring compounds such as tobacco flavorings.

[0038] According to a third aspect of this disclosure, a method using the aerosol generating system defined above, At least a portion of the aerosol generating substrate is placed inside the heating chamber of the aerosol generating device, The controller operates the induction heating device to supply alternating current to a plurality of first coil strands for a first period of time, thereby generating a first electromagnetic field for a first period of time, and heating a first portion of the aerosol generating substrate. The controller operates the induction heating device to supply alternating current to a plurality of second coil strands over a second period following a first period, thereby generating a second electromagnetic field over the second period and heating the second portion of the aerosol generating substrate. A method including this is provided.

[0039] A first electromagnetic field can cause preferential heating of a first inductively heatable susceptor during a first period, and a second electromagnetic field can cause preferential heating of a second inductively heatable susceptor during a second period. Thus, the first inductively heatable susceptor can be heated to a higher temperature than the second inductively heatable susceptor during the first period, while the second inductively heatable susceptor can be heated to a higher temperature than the first inductively heatable susceptor during the second period. As described above, this provides a controlled heat distribution within the aerosol generating substrate, and in particular provides selective (or "zone-divided") heating.

[0040] In one embodiment of this method, the heating chamber can define a heating zone.

[0041] The step of operating the induction heating device with a controller to supply alternating current to a plurality of first coil strands allows the generated first electromagnetic field to heat a first induction-heatable susceptor that defines a first region of the heating zone where a first portion of the aerosol-generating substrate is located. The step of operating the induction heating device with a controller to supply alternating current to a plurality of second coil strands allows the generated second electromagnetic field to heat a second induction-heatable susceptor that defines a second region of the heating zone where a second portion of the aerosol-generating substrate is located.

[0042] Therefore, this method provides selective (or "zone-divided") heating of an aerosol-generating substrate in first and second regions. In particular, a first portion of the aerosol-generating substrate located in the first region is heated by a first inductively heatable susceptor, and a second portion of the aerosol-generating substrate located in the second region is heated by a second inductively heatable susceptor. As described above, the heating of the first and second portions of the aerosol-generating substrate is typically continuous. [Brief explanation of the drawing]

[0043] [Figure 1] This is a schematic cross-sectional view of an aerosol generation system, including an aerosol generation device and an aerosol generation article to be placed inside the heating chamber of the aerosol generation device. [Figure 2] Figure 1 is a schematic cross-sectional view of the aerosol generation system, showing the aerosol-generating article placed inside the heating chamber of the aerosol generation device. [Figure 3] Figures 1 and 2 show a detailed schematic perspective view of the heating chamber of the aerosol generating device, illustrating the first and second inductively heatable susceptors mounted on the inner surface of the heating chamber. [Figure 4] Figure 3 is a schematic cross-sectional view from the end of the heating chamber, showing first and second induction-heatable susceptors spaced apart around the periphery of the heating chamber. [Figure 5]This is a schematic perspective view of the induction coil of an aerosol generating device, showing the first and second coil portions within the coil casing in cross-section. [Modes for carrying out the invention]

[0044] Herein, embodiments of the present disclosure will be described with reference to the attached drawings, merely as examples.

[0045] First, referring to Figures 1 and 2, an example of an aerosol generating system 1 is schematically shown. The aerosol generating system 1 includes an aerosol generating device 10 and an aerosol generating article 100 used with the device 10. The aerosol generating device 10 includes a body 12 that houses various components of the aerosol generating device 10. The body 12 may have any shape that is compatible with the components described in the various embodiments presented herein and is sized to be comfortably held by a user with one hand without assistance.

[0046] The first end 14 of the aerosol generating device 10, shown on the bottom side in Figures 1 and 2, will be described for convenience as the distal side, bottom, base, or lower end of the aerosol generating device 10. The second end 16 of the aerosol generating device 10, shown on the top side in Figures 1 and 2, will be described as the proximal side, top, or upper end of the aerosol generating device 10. During use, the user typically directs the aerosol generating device 10 with the first end 14 facing downward and / or distal to the user's mouth, and the second end 16 facing upward and / or close to the user's mouth.

[0047] The aerosol generating device 10 includes a heating chamber 18 located within a main body 12. The heating chamber 18 defines a heating zone 19 within an internal volume in the form of a cavity 20 having a substantially cylindrical cross-section for receiving an aerosol generating article 100. The heating chamber 18 has a longitudinal axis defining its longitudinal direction and is formed from a heat-resistant plastic material such as polyetheretherketone (PEEK). The aerosol generating device 10 further includes a power supply 22 (e.g., one or more batteries, which may be rechargeable) and a controller 24.

[0048] The heating chamber 18 is open toward the second end 16 of the aerosol generating device 10. In other words, the heating chamber 18 has a first end 26 that is open toward the second end 16 of the aerosol generating device 10. The heating chamber 18 is typically held at a distance from the inner surface of the body 12, which is to minimize heat transfer to the body 12.

[0049] The aerosol generating device 10 may optionally include a laterally movable slide cover 28 that covers the open first end 26 of the heating chamber 18 to prevent access to the heating chamber 18 (see Figure 1) and an open position that exposes the open first end 26 of the heating chamber 18 to provide access to the heating chamber 18 (see Figure 2). In some embodiments, the slide cover 28 can be biased to the closed position.

[0050] The heating chamber 18, specifically the cavity 20, is configured to receive a substantially cylindrical or rod-shaped aerosol generating article 100 of a corresponding shape. Typically, the aerosol generating article 100 includes a pre-packaged aerosol generating substrate 102. The aerosol generating article 100 is a disposable and replaceable article (also known as a “consumable”) which may include, for example, a cigarette as the aerosol generating substrate 102. The aerosol generating article 100 has a proximal end 104 (or mouth end) and a distal end 106. The aerosol generating article 100 further includes a mouthpiece segment 108 positioned downstream of the aerosol generating substrate 102. The aerosol generating substrate 102 and the mouthpiece segment 108 are arranged coaxially within a wrapper 110 (e.g., a paper wrapper) to hold the components in place and form a rod-shaped aerosol generating article 100.

[0051] The mouthpiece segment 108 may include one or more of the following components (not shown in detail), namely a cooling segment, a central hole segment, and a filter segment, arranged sequentially and coaxially in the downstream direction, in other words, from the distal end 106 to the proximal (mouth) end 104 of the aerosol generating article 100. The cooling segment typically includes a hollow paper tube having a thickness greater than the thickness of the wrapper 110. The central hole segment may include a cured mixture containing cellulose acetate fibers and a plasticizer, which functions to increase the strength of the mouthpiece segment 108. The filter segment typically includes cellulose acetate fibers and functions as a mouthpiece filter. As heated vapor flows from the aerosol generating substrate 102 toward the proximal (mouth) end 104 of the aerosol generating article 100, the vapor is cooled and condensed as it passes through the cooling segment and the central hole segment, forming an aerosol with properties suitable for user inhalation through the filter segment.

[0052] Referring further to Figures 3 and 4, the heating chamber 18 has a side wall (or chamber wall) 30 extending between a base 32 located at the second end 34 of the heating chamber 18 and the open first end 26. The side wall 30 and the base 32 can be connected to each other and formed as a single unit. In the illustrated embodiment, the side wall 30 is tubular, more specifically cylindrical. In another embodiment, the side wall 30 may be of any other suitable shape, for example, tubular with an elliptical or polygonal cross-section. In yet another embodiment, the side wall 30 may be tapered.

[0053] In the illustrated embodiment, the base 32 of the heating chamber 18 is closed, for example, sealed or airtight. That is, the heating chamber 18 is cup-shaped. This ensures that the base 32 prevents air drawn in from the open first end 26 from flowing out from the second end 34, and instead guides it through the aerosol generating substrate 102. This also ensures that the user inserts the aerosol generating article 100 into the heating chamber 18 to the intended distance and not beyond.

[0054] The side wall 30 of the heating chamber 18 has an inner surface 36 and an outer surface 38. The aerosol generating device 10 includes first and second inductively heated susceptors 40, 42 mounted on the inner surface 36 of the side wall 30 within the heating zone 19. In the illustrated example, each of the first and second inductively heated susceptors 40, 42 is tangent to the side wall at an angle of less than 180°, and therefore, together the first and second inductively heated susceptors 40, 42 extend circumferentially around substantially the entire circumference of the inner surface 36 of the side wall 30. The first inductively heated susceptor 40 defines a first region 41 for heating within the heating zone 19, and the second inductively heated susceptor 42 defines a second region 43 for heating within the heating zone 19.

[0055] The first and second induction-heatable susceptors 40, 42 extend along the longitudinal direction of the heating chamber 18. Each of the first and second induction-heatable susceptors 40, 42 has a length and a width, typically the length being at least five times the width. Those skilled in the art will understand that the first and second induction-heatable susceptors 40, 42 are not limited to the dimensional shapes shown in Figures 3 and 4, and that other dimensional shapes are also fully within the scope of this disclosure.

[0056] The first and second induction-heatable susceptors 40 and 42 each have inner surfaces 40a and 42a that contact the aerosol-generating substrate 102. The first and second induction-heatable susceptors 40 and 42 can form frictional engagement with the aerosol-generating substrate 102, more specifically with the wrapper 110 of the aerosol-generating article 100, and can cause compression of the aerosol-generating substrate 102, as best shown in Figure 2. Compression of the aerosol-generating substrate 102 improves heat conduction through the aerosol-generating substrate 102, for example, by eliminating voids within the aerosol-generating substrate 102.

[0057] The aerosol generating device 10 includes an induction heating device 46 for heating the aerosol generating substrate 102. The induction heating device 46 includes a substantially helical induction coil 48. The induction coil 48 extends helically around a substantially cylindrical heating chamber 18. The induction coil 48 can be energized by a power supply 22 and a controller 24. The controller 24 includes, among other electronic components, an inverter arranged to convert a DC current from the power supply 22 into an AC high-frequency current for the induction coil 48.

[0058] The side wall 30 of the heating chamber 18 includes a coil support structure 50 formed on its outer surface 38. In the illustrated example, the coil support structure 50 includes a coil support groove 52 that extends spirally around the outer surface 38. The induction coil 48 is positioned within the coil support groove 52 and is therefore securely and optimally positioned relative to the first and second induction-heatable susceptors 40, 42.

[0059] Referring to Figure 5, the induction coil 48 includes a coil periphery 54 in cross-section, and the coil periphery 54 defines the cross-sectional coil sheath 56. An outer insulator (not shown) may surround the coil periphery 54. Within the cross-sectional coil sheath 56 are a first coil portion 58 and a second coil portion 60 electrically insulated from the first coil portion 58. The first coil portion 58 includes a plurality of first coil strands 62, and the second coil portion 60 includes a plurality of second coil strands 64. In the illustrated example, the first coil strands 62 have a first cross-sectional area, and the second coil strands 64 have a second cross-sectional area that is larger than the first cross-sectional area. However, this configuration is not essential, and it may suffice if the first coil strands 62 have a first cross-section and the second coil strands 64 have a second cross-section that is different from the first cross-section. Here, the term "cross section" may include one or more of the cross-sectional area and / or cross-sectional shape. It should also be noted that the first and second coil sections 58 and 60 do not necessarily have to be semicircular as shown in Figure 5, and other configurations such as a concentric configuration of the first and second coil sections 58 and 60 are also possible.

[0060] To use the aerosol generating device 10, the user moves the slide cover 28 (if present) from the closed position shown in Figure 1 to the open position shown in Figure 2. The user then inserts the aerosol generating article 100 into the heating chamber 18 through the open first end 26, so that the aerosol generating substrate 102 is received within the heating zone 19 defined by the cavity 20, and the proximal end 104 of the aerosol generating article 100 is positioned at the open first end 26 of the heating chamber 18, with at least a portion of the mouthpiece segment 108 protruding from the open first end 26 to allow engagement by the user's lips.

[0061] When the user activates the aerosol generating device 10, the induction heating device 46 is energized by the power supply 22 and the controller 24. More specifically, according to this disclosure, the controller 24 is configured to control the induction heating device 46, more specifically the power supply 22 and the control circuit, to supply alternating current to a plurality of first coil strands 62 of the first coil portion 58 to generate a first electromagnetic field having a first frequency, and to supply alternating current to a plurality of second coil strands 64 of the second coil portion 60 to generate a second electromagnetic field having a second frequency.

[0062] The first and second inductively heated susceptors 40 and 42 have different resonant frequencies. A first electromagnetic field having a first frequency causes preferential heating of the first inductively heated susceptor 40 (by eddy currents and / or magnetic hysteresis losses generated within the first inductively heated susceptor 40), and therefore, the heat transmitted from the first inductively heated susceptor 40 causes preferential heating of the first portion of the aerosol generating substrate 102 located in the first region 41 of the heating zone 19. A second electromagnetic field having a second frequency causes preferential heating of the second inductively heated susceptor 42 (by eddy currents and / or magnetic hysteresis losses generated within the second inductively heated susceptor 42), and therefore, the heat transmitted from the second inductively heated susceptor 42 causes preferential heating of the second portion of the aerosol generating substrate 102 located in the second region 43 of the heating zone 19. Therefore, selective (or "zone-divided") heating of the first and second portions of the aerosol generating substrate 102 is achieved in the first and second regions 41, 43 within the heating zone 19. When the aerosol generating substrate 102 is heated by the first or second inductively heatable susceptors 40, 42, the aerosol generating substrate 102 is heated without burning or combustion, thereby generating vapor. The generated vapor cools and condenses to become an aerosol that can be inhaled by the user of the aerosol generating device 10 through the mouthpiece segment 108 (more specifically, the filter segment).

[0063] The controller 24 is typically configured to supply alternating current to a plurality of first coil strands 62 in the first coil section 58 over a first period to generate a first electromagnetic field (having a first frequency) over the first period. Subsequently, the controller 24 is typically configured to supply alternating current to a plurality of second coil strands 64 in the second coil section 60 over a second period to generate a second electromagnetic field (having a second frequency) over the second period. Therefore, since the supply of alternating current to the plurality of first coil strands 62 and the plurality of second coil strands 64 occurs sequentially rather than simultaneously, the generation of the first and second electromagnetic fields (having their corresponding first and second frequencies) is also continuous. Thus, during the first period, the first inductively heatable susceptor 40 is preferentially heated by the first electromagnetic field, and during the second period, the second inductively heatable susceptor 42 is preferentially heated by the second electromagnetic field. This provides continuous, and therefore selective (or "zone-divided") heating of the first and second portions of the aerosol generating substrate 102 located in the first and second regions 41 and 43, respectively, within the heating zone 19.

[0064] The vaporization of the aerosol generating substrate 102 is facilitated by air from the surrounding environment being added, for example, through the open first end 26 of the heating chamber 18, which is heated as it flows between the wrapper 110 and the inner surface 36 of the side wall 30 of the aerosol generating article 100, which has a circumferential gap between the longitudinal edges of the first and second inductively heatable susceptors 40, 42. More specifically, when a user inhales the filter segment, air is drawn into the heating chamber 18 through the open first end 26, as shown by arrow A in Figure 2. The air that enters the heating chamber 18 flows between the wrapper 110 and the inner surface 36 of the side wall 30 from the open first end 26 towards the closed second end 34. As described above, the inner surfaces 40a, 42a of the first and second inductively heated susceptors 40, 42 can come into contact with the outer surface of the aerosol generating article 100, which can typically cause at least some degree of compression of the aerosol generating substrate 102. As a result, there is no circumferential gap around the heating chamber 18. Instead, there is an air passage 66 in a circumferential region (two gap regions) between the longitudinal edges of the first and second inductively heated susceptors 40, 42, along which air flows from the open first end 26 to the closed second end 34 of the heating chamber 18. In some examples, three or more inductively heated susceptors 40, 42 can be used, and thus a corresponding number of air passages 66 can be formed by the gap regions between the longitudinal edges of circumferentially adjacent inductively heated susceptors. As this air reaches the closed second end 34 of the heating chamber 18, it bends approximately 180° and enters the distal end 106 of the aerosol generating article 100. The air, along with the generated vapor, is then drawn through the aerosol generating article 100 from the distal end 106 to the proximal (mouth) end 104, as indicated by arrow B in Figure 2.

[0065] While exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications to these embodiments can be made without departing from the scope of the attached claims. Therefore, the breadth and scope of the claims should not be limited to the exemplary embodiments described above.

[0066] Unless otherwise stated herein or unless clearly inconsistent with the context, any combination of any possible variations thereof of the features described above is encompassed by this disclosure.

[0067] The present invention has been described with reference to an example in which the cross-sectional area of ​​the first coil strand differs from that of the second coil strand. However, it will be understood that, if necessary, the first coil strand may differ from the second coil strand in other respects. For example, in order to generate different first and second electromagnetic fields, the first coil strand may have a different cross-sectional shape (as well as a different cross-sectional area, or instead) and / or may be formed from a different material than the second coil strand. It will also be understood that the first coil strand may be the same as the second coil strand (i.e., having the same cross-section and material), or instead, the first coil strand may be energized by a controller with a different alternating current than the second coil strand to generate different first and second electromagnetic fields. In any of these cases, in order to ensure that the coil portion is energized substantially independently, the first coil strand is electrically insulated from the second coil strand (e.g., separated by an insulator) as described above.

[0068] Unless the context clearly indicates otherwise, throughout this specification and the claims, words such as “includes” and “contains” should be interpreted in an inclusive sense, i.e., “includes, but not limited to,” rather than in an exclusive or exhaustive sense.

Claims

1. Aerosol generating device (10), Controller (24) and An induction heating device (46) configured to heat an aerosol generating substrate (102) to generate an inhaled aerosol, comprising an induction coil (48) including at least a plurality of first coil strands (62) and a plurality of second coil strands (64), The controller (24) is configured to control the induction heating device (46) to supply alternating current to the plurality of first coil strands (62) to generate a first electromagnetic field having a first frequency, and to supply alternating current to the plurality of second coil strands (64) to generate a second electromagnetic field having a second frequency different from the first frequency, in the aerosol generating device (10).

2. The aerosol generating device according to claim 1, wherein the induction coil (48) includes a first coil portion (58) on which the plurality of first coil strands (62) are arranged, and a second coil portion (60) on which the plurality of second coil strands (64) are arranged.

3. The aerosol generating device according to claim 2, wherein the induction coil (48) includes a peripheral portion (54) that defines the cross-sectional coil sheath (56), and the first coil portion (58) and the second coil portion (60) are arranged within the cross-sectional coil sheath (56).

4. The aerosol generating device according to claim 2, wherein the first coil portion (58) and the second coil portion (60) are electrically insulated from each other.

5. The aerosol generating device according to claim 1, wherein the plurality of first coil strands (62) have a first cross-section, and the plurality of second coil strands (64) have a second cross-section different from the first cross-section.

6. The aerosol generating device according to claim 5, wherein the plurality of first coil strands (62) and the plurality of second coil strands (64) differ from each other in one or more of their cross-sectional shapes and cross-sectional areas.

7. The aerosol generating device according to claim 1, wherein the controller (24) is configured to sequentially supply the alternating current to the plurality of first coil strands (62) and the plurality of second coil strands (64) to sequentially generate the first electromagnetic field and the second electromagnetic field.

8. The aerosol generating device according to claim 1, wherein the controller (24) is configured to supply the alternating current to the plurality of first coil strands (62) for a first period to generate the first electromagnetic field for the first period, and thereafter to supply the alternating current to the plurality of second coil strands (64) for a second period following the first period to generate the second electromagnetic field for the second period.

9. The aerosol generating device according to claim 1, comprising a heating chamber (18) defining a heating zone (19) for receiving at least a portion of an aerosol generating substrate (102), and the induction coil (48) being positioned adjacent to the heating chamber (18) to generate the first and second electromagnetic fields within the heating zone (19).

10. The aerosol generating device according to claim 9, wherein the first electromagnetic field is adapted to heat a first inductively heatable susceptor (40) having a first resonant frequency, and the second electromagnetic field is adapted to heat a second inductively heatable susceptor (42) having a second resonant frequency different from the first resonant frequency.

11. The aerosol generating device according to claim 10, comprising the first induction-heatable susceptor (40) and the second induction-heatable susceptor (42).

12. The aerosol generating device according to claim 11, wherein the first induction-heatable susceptor (40) and the second induction-heatable susceptor (42) are arranged around the heating chamber (18) within the heating zone (19) to define a first region (41) and a second region (43) within the heating zone (19), respectively, and the induction coil (48) extends spirally around the heating chamber (18).

13. Aerosol generation system (1), Aerosol generating substrate (102) and An aerosol generating device (10) according to any one of claims 1 to 12 for heating the aerosol generating substrate (102) to generate an inhaled aerosol, an aerosol generation system (1) including the above.

14. A method using the aerosol generating system (1) described in claim 13, At least a portion of the aerosol generating substrate (102) is placed inside the heating chamber (18) of the aerosol generating device (10), The controller (24) operates the induction heating device (46) to supply alternating current to the plurality of first coil strands (62) for a first period of time to generate the first electromagnetic field for the first period of time to heat the first portion of the aerosol generating substrate (102), The controller (24) operates the induction heating device (46) to supply alternating current to the plurality of second coil strands (64) over a second period following the first period, thereby generating the second electromagnetic field over the second period and heating the second portion of the aerosol generating substrate (102). A method that includes this.

15. The heating chamber (18) defines a heating zone (19), The controller (24) operates the induction heating device (46) to supply the alternating current to the plurality of first coil strands (62), thereby heating the first induction-heatable susceptor (40) that defines the first region (41) of the heating zone (19) where the first portion of the aerosol generating substrate (102) is located, and The method according to claim 14, wherein the controller (24) operates the induction heating device (46) to supply the alternating current to the plurality of second coil strands (64), thereby heating a second induction-heatable susceptor (42) that defines a second region (43) of the heating zone (19) where the second portion of the aerosol generating substrate (102) is located, with the generated second electromagnetic field.

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