Aerosol generating device and aerosol generating system

Abstract

The aerosol generating device (10) comprises a heating chamber (18) for receiving at least a portion of an aerosol-generating substrate (102) and an induction heating arrangement (46) configured to heat the aerosol-generating substrate (102) to generate an inhaled aerosol, the induction heating arrangement (46) comprising a single induction coil (48) disposed around or adjacent the heating chamber (18). The aerosol generating device (10) comprises a controller (24) configured to control the induction heating arrangement (46) to supply an alternating current to the single induction coil (48). The induction heating arrangement (46) comprises a plurality of connectors (C1-C5) associated with the single induction coil (48), the plurality of connectors (C1-C5) being arranged and configured to supply an alternating current to one or more coil sections (L1-L4) to enable selective energization of one or more coil sections (L1-L4). The aerosol generation device (10) also includes a plurality of inductively heatable susceptors (40, 41, 42, 43) positioned within the heating chamber (18) adjacent each coil section (L1-L4) so ​​as to define corresponding heating regions (40a, 41a, 42a, 43a) within the heating chamber (18).

Description

[Technical field]

[0001] The present disclosure generally relates to an aerosol generating device, and more specifically to an aerosol generating device for heating an aerosol-generating substrate to generate an aerosol for inhalation by a user. Also, embodiments of the present disclosure relate to an aerosol generating system comprising an aerosol generating device and an aerosol-generating substrate, and a method of generating an aerosol to be inhaled using an aerosol generating system. The present disclosure is particularly applicable to portable (handheld) aerosol generating devices. Such devices heat an aerosol-generating substrate, e.g., tobacco or other suitable material, by conduction, convection, and / or radiation, rather than combustion, to generate an aerosol for inhalation by a user. The present disclosure particularly relates to an inductively heated aerosol generating device and / or system. [Background technology]

[0002] In recent years, the popularity and use of risk-reducing or risk-modifying devices (also known as aerosol-generating devices or vapour-generating devices or personal vaporisers) has grown rapidly as an alternative to the use of traditional tobacco products. A variety of devices and systems are available that heat or warm an aerosol-generating substrate to generate an aerosol that is inhaled by the user.

[0003] Commonly available risk reduction or risk modification devices are substrate heated aerosol generating devices or so-called heated non-combustion devices. This type of device generates an aerosol or vapour by heating an aerosol-generating substrate to a temperature typically in the range of 150°C to 300°C. Heating the aerosol-generating substrate to a temperature within this range, without burning or combusting the aerosol-generating substrate, generates a vapour which typically cools and condenses to form an aerosol for inhalation by a user of the device.

[0004] Currently available aerosol-generating devices can heat the aerosol-generating substrate using one of several different approaches. One such approach is to provide an aerosol-generating device that employs an induction heating system. In such devices, an induction coil is provided in the device and an inductively heatable susceptor is provided to heat the aerosol-generating substrate. When a user activates the device, electrical energy is supplied to the induction coil, which in turn generates an alternating electromagnetic field. The susceptor couples with the electromagnetic field to generate heat, which is transferred to the aerosol-generating substrate, for example, by one or more of conduction, radiation, and convection, and as the aerosol-generating substrate is heated, an aerosol is generated.

[0005] Generally, it is desirable to control the heat distribution within the aerosol-generating substrate to ensure that an aerosol is generated having acceptable characteristics for inhalation by a user throughout the period of use (also known as a smoking session). Embodiments of the present disclosure seek to provide an improved user experience, in which the characteristics of the aerosol generated are optimized through more precise control of the heat distribution within the aerosol-generating substrate. Summary of the Invention

[0006] According to a first aspect of the present disclosure, a heating chamber for receiving at least a portion of the aerosol-generating substrate; an induction heating arrangement configured to heat the aerosol-generating substrate to generate an inhaled aerosol, the induction heating arrangement comprising a single induction coil disposed around or adjacent the heating chamber; a controller configured to control the induction heating arrangement to supply an alternating current to the single induction coil; An aerosol generating device is provided, comprising: the induction heating arrangement includes a plurality of connectors associated with the single induction coil, the plurality of connectors positioned and configured to provide alternating current to one or more coil sections of the single induction coil to enable selective energization of the one or more coil sections; the aerosol generating device comprising a plurality of inductively heatable susceptors positioned within the heating chamber proximate each coil section to define corresponding heating regions within the heating chamber; The aerosol generating device has at least two heating modes, each heating mode having an associated section activation pattern, and the controller is configured to control the induction heating arrangement to supply alternating current to the one or more coil sections of the single induction coil according to a first section activation pattern when a first heating mode is selected, and to supply alternating current to the one or more coil sections of the single induction coil according to a second section activation pattern that is different from the first section activation pattern when a second heating mode is selected.

[0007] The aerosol generating device is configured to heat, without burning, the aerosol-generating substrate to evaporate at least one component of the aerosol-generating substrate, thereby generating a vapour which cools and condenses to form an aerosol for inhalation by a user of the aerosol generating device. The aerosol generating device is typically a handheld, portable device.

[0008] Generally speaking, a vapor is a substance that is in the gas phase below its critical temperature, meaning that it can be condensed into a liquid by increasing the pressure without decreasing the temperature, whereas an aerosol is fine solid particles or liquid droplets suspended in air or another gas. However, it should be noted that the terms "aerosol" and "vapor" may be used interchangeably herein, particularly with respect to the form of inhalable medium that is produced for inhalation by a user.

[0009] By selectively energizing one or more of the coil sections, the present disclosure allows for careful control of the heat distribution within the aerosol-generating substrate, for example, since each coil section (when energized) may result in preferential heating of an inductively heatable susceptor located in the vicinity of that particular coil section. Thus, selective (or "zonal") heating of the aerosol-generating substrate may be achieved. The use of a single induction coil with coil sections that can be selectively energized (sequentially or simultaneously) via connectors provides an effective solution for selectively heating the inductively heatable susceptor, ensuring that the aerosol-generating device has a compact design. Providing the inductively heatable susceptor as part of the aerosol-generating device, rather than together with the aerosol-generating substrate as part of the aerosol-generating article, may also simplify the construction and manufacture of the aerosol-generating article. By providing two or more heating modes, each with an associated section activation pattern (i.e., a predetermined order in which the coil sections activate), the aerosol-generating device may be switchable between multiple heating modes that coordinate the operation of the device, thus providing the user with greater flexibility regarding the operation of the device. Additionally, multiple heating modes may provide more consistent heating during a usage session.

[0010] Optional features will now be described, which may be applied alone or in any combination with any aspect of the present disclosure.

[0011] The connectors may be arranged in pairs to allow for the supply of alternating current to each coil section via a corresponding pair of the connectors, and the controller may be configured to supply alternating current to each coil section via a corresponding pair of the connectors, such that each coil section is defined by, and may be conveniently energized via, a selected pair of the connectors.

[0012] The multiple connectors may be arranged and configured such that, in use, each coil section generates an electromagnetic field that is concentrated in a different region of the heating chamber corresponding to the location of an inductively heatable susceptor positioned nearby, ensuring that an inductively heatable susceptor positioned nearby a coil section is preferentially heated by the electromagnetic field generated by that coil section.

[0013] The single induction coil may be a helical coil extending around the heating chamber about a longitudinal axis. Providing an induction coil that extends helically around the heating chamber may ensure reliable heating of the inductively heatable susceptor. The connectors may be spaced along the longitudinal axis to define longitudinally disposed coil sections, whereby each coil section may include a subset of the total number of turns of a helical coil. The inductively heatable susceptors may be correspondingly spaced along the longitudinal axis to provide selective (or "zonal") heating of longitudinally disposed portions of the aerosol-generating substrate.

[0014] In the first section activation pattern, the controller may be configured to supply alternating current to each coil section sequentially. In the second section activation pattern, the controller may be configured to supply alternating current to a plurality of subsets of coil sections sequentially. This may result in each coil section, or subsets of coil sections, generating an electromagnetic field at a different time (i.e. not all of the coil sections generate an electromagnetic field at the same time). This advantageously allows different regions or parts of the aerosol-generating substrate to be heated sequentially, thus providing a controlled heat distribution within the aerosol-generating substrate, in particular selective (or "zone-by-zone") heating. In a third section activation pattern, the controller may be configured to supply alternating current to all of the coil sections simultaneously. In that way, rapid heating of the aerosol-generating substrate may be achieved.

[0015] The controller may be configured to control the electromagnetic induction heating arrangement to supply an alternating current to a first coil section to generate a first electromagnetic field, and the controller may be configured to control the electromagnetic induction heating arrangement to supply an alternating current to a second coil section to generate a second electromagnetic field.

[0016] The first and second electromagnetic fields do not have to occur simultaneously, but instead may occur at different times. This advantageously allows different regions or parts of the aerosol-generating substrate to be heated sequentially, thereby providing a controlled heat distribution within the aerosol-generating substrate, in particular selective (or "zonal") heating.

[0017] The first electromagnetic field may have a first frequency and the second electromagnetic field may have a second frequency different from the first frequency. By generating first and second electromagnetic fields with different first and second frequencies, it is possible to carefully control the heat distribution inside the aerosol-generating substrate, since for example the first electromagnetic field may produce preferential heating of a first inductively heatable susceptor and the second electromagnetic field may produce preferential heating of a second inductively heatable susceptor. In that way, selective (or "zonal") heating of the aerosol-generating substrate can be achieved. The use of a single electromagnetic induction coil to generate the first electromagnetic field (e.g. via a first coil section) and the second electromagnetic field (e.g. via a second coil section) provides an effective solution for generating the first and second electromagnetic fields and ensures that the aerosol-generating device has a compact design.

[0018] Each of the inductively heatable susceptors may have a resonant frequency that is different from the resonant frequencies of the other inductively heatable susceptors. For example, the aerosol generating device may include a first inductively heatable susceptor having a first resonant frequency and a second inductively heatable susceptor having a second resonant frequency that is different from the first resonant frequency.

[0019] Using inductively heatable susceptors having different resonant frequencies allows selective (or "zonal") heating of the aerosol-generating substrate to be performed by controlling the inductive heating arrangement such that a first coil section generates a first electromagnetic field having a first frequency that is approximately equal to a first resonant frequency of the first inductively heatable susceptor, and a second coil section generates a second electromagnetic field having a second frequency that is approximately equal to a second resonant frequency of the second inductively heatable susceptor. Generating an electromagnetic field (e.g., a first or second electromagnetic field) having a frequency (e.g., a first or second frequency) that is approximately equal to the resonant frequency (e.g., a first or second resonant frequency) of a particular susceptor (e.g., a first or second susceptor) generates a quantity of heat in that susceptor. This may also result in the amount of heat generated in one or more of the other susceptors (i.e., in any susceptors having a resonant frequency that is not substantially equal to the frequency of the generated electromagnetic field) being typically less than the amount of heat generated by the particular susceptor, and may be zero or nearly zero. Any selective heating of a particular susceptor should therefore not be construed to mean that other susceptors are not heated at all, but only that the selective heating of a particular susceptor is typically primarily responsible for the emission of aerosol from the aerosol-generating substrate in the vicinity of the particular susceptor. Throughout this specification, the term "preferential heating" is used to define this type of heating. This preferential heating may advantageously allow one or more portions of the aerosol-generating substrate to be heated to a higher temperature than one or more other portions of the aerosol-generating substrate. Heating one or more portions to a higher temperature may provide rapid aerosol generation initially when the aerosol generating device is activated, while heating one or more portions to a lower temperature may provide sustained aerosol generation throughout a period of use (e.g., a smoking session).

[0020] The controller may be configured to control the electromagnetic induction heating arrangement to supply an alternating current to a third coil section to generate a third electromagnetic field. The controller may be configured to control the electromagnetic induction heating arrangement to supply an alternating current to a fourth coil section to generate a fourth electromagnetic field. The third electromagnetic field may have a third frequency. The fourth electromagnetic field may have a fourth frequency. The third frequency may be different from the first and second frequencies and may be different from the fourth frequency. The fourth frequency may be different from the first and second frequencies and may be different from the third frequency. The third electromagnetic field may be adapted to heat a third inductively heatable susceptor at its third frequency, which may have a third resonant frequency, which may be different from the first and second resonant frequencies and may be different from the fourth resonant frequency. The fourth electromagnetic field may be adapted to heat a fourth inductively heatable susceptor, which may have a fourth resonant frequency at its fourth frequency, which may be different from the first and second resonant frequencies and may be different from the third resonant frequency.

[0021] The use of additional coil sections, such as a third coil section and optionally a fourth coil section, along with an inductively heatable susceptor having corresponding third and fourth resonant frequencies, may allow greater control over the heating of the aerosol-generating substrate, thereby enhancing selective (or "zone-by-zone") heating of the aerosol-generating substrate.

[0022] In a first heating mode, the controller may be configured to control the induction heating arrangement to sequentially supply alternating current to each of the first, second, third and fourth coil sections in a first section activation pattern. In an exemplary first section activation pattern, each of the first, second, third and fourth inductively heatable susceptors is sequentially heated such that the first, second, third and fourth portions of the aerosol-generating substrate are sequentially heated. Heating may commence with any one of the first, second, third and fourth sections. The order may be reversed if required. The coil may comprise more or less than four sections.

[0023] In a second heating mode, the controller may be configured to control the induction heating arrangement to simultaneously supply alternating current to a first subset of coil sections and then simultaneously supply alternating current to a second subset of coil sections in a second section activation pattern. In an exemplary second section activation pattern, the controller may be configured to simultaneously supply alternating current to the first and second coil sections and then simultaneously supply alternating current to the third and fourth coil sections. In this example, the first and second inductively heatable susceptors are heated simultaneously, thereby also simultaneously heating the first and second portions of the aerosol-generating substrate. Then, the third and fourth inductively heatable susceptors are heated simultaneously, thereby also simultaneously heating the third and fourth portions of the aerosol-generating substrate. In another example, the first and third inductively heatable susceptors are heated simultaneously, thereby also simultaneously heating the first and third portions of the aerosol-generating substrate. Then, the second and fourth inductively heatable susceptors are heated simultaneously, thereby also simultaneously heating the second and fourth portions of the aerosol-generating substrate. In a further embodiment, the first and fourth inductively heatable susceptors are heated simultaneously, thereby heating the first and fourth portions of the aerosol-generating substrate simultaneously. Then, the second and third inductively heatable susceptors are heated simultaneously, thereby heating the second and third portions of the aerosol-generating substrate simultaneously. It will be appreciated that the subsets may be activated in different orders and other subsets may be selected as desired.

[0024] In a third heating mode, the controller may be configured to control the induction heating arrangement to simultaneously supply alternating current to the first, second, third and fourth coil sections in a third section activation pattern, in this embodiment, the first, second, third and fourth inductively heatable susceptors are heated simultaneously, thereby simultaneously heating the first, second, third and fourth portions of the aerosol-generating substrate.

[0025] It will be appreciated that other combinations of coil sections and subsets of coil sections may be selected to define further example section activation patterns, for example, in a further sequential section activation pattern, a first coil section is activated, followed by a first subset of coil sections including a second coil section and a third coil section, followed by a fourth coil section.

[0026] The controller may be configured to control the induction heating arrangement to heat a first coil section in a subset of the coil sections (e.g., a first subset) to a first temperature and simultaneously heat a second coil section in the same subset to a second temperature.

[0027] The controller may be user adjustable or user configurable to allow a user to control the supply of alternating current to the coil sections via the induction heating arrangement. In other words, a user may select how the coil sections are energized, for example according to the first, second, or third non-limiting examples described above. These first, second, and third non-limiting examples may represent "heating modes" of the aerosol generating device that a user may select.

[0028] The induction coil may comprise Litz wire or Litz cable, however, it will be appreciated that other materials may be used.

[0029] The induction coil may be arranged, in use, to operate with a varying electromagnetic field having a magnetic flux density of about 20 mT to about 2.0 T (at its highest density point).

[0030] The heating chamber may have a longitudinal axis defining a longitudinal direction. The heating chamber may be generally tubular. A plurality of inductively heatable susceptors may extend circumferentially around the generally tubular heating chamber, e.g., may comprise a susceptor ring. As mentioned above, the plurality of inductively heatable susceptors may be spaced apart longitudinally, i.e., along the longitudinal axis, along the heating chamber. The heating chamber may be generally cylindrical. The heating chamber may thus be configured to receive a generally cylindrical aerosol-generating substrate, which may be advantageous since aerosol-generating substrates in the form of aerosol-generating articles are often packaged and sold in a cylindrical shape. The inductively heatable susceptors are efficiently heated in the presence of electromagnetic fields generated by adjacent coil sections, thereby ensuring rapid and uniform heating of the aerosol-generating substrate. This maximizes the energy efficiency of the aerosol-generating device.

[0031] The heating chamber may comprise a substantially electrically non-conductive and non-magnetically permeable 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 arrangement, ensuring that the energy input to the inductively heatable susceptor is maximized. This in turn ensures that the energy efficiency of the device is maximized. The device also remains cool to the touch, ensuring that user comfort is maximized.

[0032] The inductively heatable susceptor may comprise a metal. The metal is typically selected from the group consisting of stainless steel and carbon steel. The inductively heatable susceptor may comprise any suitable material, including, but not limited to, one or more of aluminum, iron, nickel, stainless steel, carbon steel, and alloys thereof, such as nickel-chromium or nickel-copper. Each inductively heatable susceptor produces heat upon application of an electromagnetic field in the vicinity of the susceptor due to eddy currents and magnetic hysteresis losses resulting in electromagnetic-to-thermal energy conversion.

[0033] The aerosol generating device may include a power source and the controller may include a control circuit. The power source and the control circuit may be configured to operate at high frequencies. The power source and the control circuit may be configured to operate at frequencies of about 80 kHz to 1 MHz, optionally about 150 kHz to 250 kHz, optionally about 200 kHz. The power source and the control circuit may be configured to operate at higher frequencies, for example in the MHz range, depending on the type of inductively heatable susceptor used.

[0034] According to a second aspect of the present disclosure, an aerosol-generating substrate; an aerosol-generating device as defined above for heating said aerosol-generating substrate to generate an aerosol that may be inhaled; An aerosol generating system is provided comprising:

[0035] The aerosol-generating substrate may comprise any type of solid or semi-solid material. Exemplary types of aerosol-generating solids include powders, granules, pellets, pieces, strands, particles, gels, strips, loose-leaf, cut filler, porous materials, foamed materials, or sheets. The aerosol-generating substrate may comprise a plant-derived material, in particular tobacco. It may, for example, comprise reconstituted tobacco, which comprises tobacco and any one or more of cellulose fibers, tobacco stem fibers, and inorganic fillers such as CaCO3.

[0036] Thus, the aerosol-generating device may be referred to as a "heated tobacco device," "heated non-combustion tobacco device," "device for vaporizing tobacco products," etc., and is to be construed as a device suitable for achieving these effects. The features disclosed herein are equally applicable to devices designed to vaporize any aerosol-generating substrate.

[0037] The aerosol-generating substrate may form part of the aerosol-generating article and may be surrounded by a paper wrapper.

[0038] The aerosol-generating article may be substantially formed in the shape of a stick, or may generally resemble a cigarette with a tubular region having an aerosol-generating substrate arranged in a suitable configuration. The aerosol-generating article may include a filter segment, for example comprising cellulose acetate fibers, at the proximal end of the aerosol-generating article. The filter segment may constitute a mouthpiece filter and may be coaxially aligned with the aerosol-generating substrate. One or more vapor collection regions, cooling regions, and other structures may also be included in some designs. 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 be cooled and condensed to form an aerosol having suitable properties for inhalation by a user, for example through a filter segment.

[0039] The aerosol-generating substrate may comprise an aerosol former. Examples of aerosol formers include polyhydric alcohols such as glycerin or propylene glycol and mixtures thereof. Typically, the aerosol-generating substrate may comprise an aerosol former content of about 5% to about 50% on a dry weight basis. In some embodiments, the aerosol-generating substrate may comprise an aerosol former content of about 10% to about 20% on a dry weight basis, and optionally about 15% on a dry weight basis.

[0040] When heated by one or more of the inductively heatable susceptors, the aerosol-generating substrate may emit volatile compounds, which may include nicotine, or flavor compounds, such as tobacco flavorings.

[0041] According to a third aspect of the present disclosure, there is provided a method of using an aerosol generating system as defined above, comprising the steps of: Positioning at least a portion of an aerosol-generating substrate within a heating chamber; controlling, by the controller, the induction heating arrangement to supply alternating current to one or more coil sections of the single induction coil according to a first section activation pattern when a first heating mode is selected; controlling, by the controller, the induction heating arrangement to supply alternating current to one or more coil sections of the single induction coil according to a second section activation pattern that is different from the first section activation pattern when a second heating mode is selected; A method is provided that includes:

[0042] Supplying an alternating current in accordance with the first section activation pattern may include activating, by the controller, the induction heating arrangement to supply an alternating current to a first coil section for a first time period to generate a first electromagnetic field for the first time period to heat a first portion of the aerosol-generating substrate, and thereafter activating, by the controller, the induction heating arrangement to supply an alternating current to a second coil section for a second time period following the first time period to generate a second electromagnetic field for the second time period to heat a second portion of the aerosol-generating substrate.

[0043] Supplying an alternating current in accordance with the second section activation pattern may include activating, by the controller, the induction heating arrangement to supply an alternating current to a first subset of coil sections for a first time period to generate a first set of electromagnetic fields during the first time period to heat the first group of portions of the aerosol-generating substrate, and thereafter activating, by the controller, the induction heating arrangement to supply an alternating current to a second subset of coil sections (different from the first subset) for a second time period following the first time period to generate a second set of electromagnetic fields during the second time period to heat the second group of portions of the aerosol-generating substrate.

[0044] The first electromagnetic field may cause preferential heating of the first inductively heatable susceptor during a first time period, and the second electromagnetic field may cause preferential heating of the second inductively heatable susceptor during a second time period. Thus, the first inductively heatable susceptor may be heated to a higher temperature than the second inductively heatable susceptor during a first time period, while the second inductively heatable susceptor may be heated to a higher temperature than the first inductively heatable susceptor during a second time period. As discussed above, this provides a controlled heat distribution within the aerosol-generating substrate, and in particular provides selective (or "zonal") heating.

[0045] Activating the induction heating arrangement to supply alternating current to a first coil section by the controller may cause the generated first electromagnetic field to heat a first inductively heatable susceptor that may define a first heating region of a heating chamber in which a first portion of an aerosol-generating substrate may be positioned, and activating the induction heating arrangement to supply alternating current to a second coil section by the controller may cause the generated second electromagnetic field to heat a second inductively heatable susceptor that may define a second heating region of a heating chamber in which a second portion of an aerosol-generating substrate may be positioned.

[0046] The method thus provides for selective (or "zonal") heating of the aerosol-generating substrate in the first and second heated zones. For example, a first portion of the aerosol-generating substrate positioned in the first heated zone is heated by a first inductively heatable susceptor and a second portion of the aerosol-generating substrate positioned in the second heated zone is heated by a second inductively heatable susceptor. As noted above, the heating of the first and second portions of the aerosol-generating substrate can be sequential or simultaneous depending on the user's preference and may be controlled by the user. [Brief description of the drawings]

[0047] [Figure 1] 1 is a schematic cross-sectional view of an aerosol generation system comprising an aerosol generating device and an aerosol-generating article ready to be positioned within a heating chamber of the aerosol generating device. [Diagram 2] 2 is a schematic cross-sectional view of the aerosol generating system of FIG. 1 showing an aerosol-generating article positioned within a heating chamber of the aerosol generating device. [Diagram 3] FIG. 3 is a detailed perspective view of the heating chamber of the aerosol generating device of FIGS. 1 and 2, showing first, second, third, and fourth inductively heatable susceptors attached to the inner surface of the heating chamber, and a coil support structure. [Figure 4]4 is a schematic cross-sectional view from an end of the heating chamber shown in FIG. 3 showing a fourth inductively heatable susceptor extending around the heating chamber. [Diagram 5] FIG. 5 is a schematic perspective view of a portion of the aerosol generating device of FIGS. 1-4, showing the induction coil and inductively heatable susceptor of the aerosol generating device, and also showing an aerosol-generating article positioned relative to the inductively heatable susceptor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0049] 1 and 2, there is shown a schematic diagram of one embodiment of an aerosol generating system 1. The aerosol generating system 1 comprises an aerosol generating device 10 and an aerosol generating article 100 for use with the device 10. The aerosol generating device 10 comprises a body 12, which houses the various components of the aerosol generating device 10. The body 12 can have any shape that is sized to fit the components described in the various embodiments herein and to be comfortably held by a user in one hand without assistance.

[0050] A first end 14 of the aerosol generating device 10, shown on the bottom side of Figures 1 and 2, is for convenience described as the distal, bottom, base or lower end of the aerosol generating device 10. A second end 16 of the aerosol generating device 10, shown on the top side of Figures 1 and 2, is described as the proximal, top or upper end of the aerosol generating device 10. During use, a user will typically orient the aerosol generating device 10 with the first end 14 facing downward and / or in a position distal to the user's mouth and the second end 16 facing upward and / or in a position proximal to the user's mouth.

[0051] The aerosol generating device 10 comprises a heating chamber 18 located within the body 12. The heating chamber 18 defines an interior volume in the form of a cavity 20 having a generally cylindrical cross-section for accommodating the aerosol generating article 100. The heating chamber 18 has a longitudinal axis defining a lengthwise direction and is formed from a heat resistant plastic material such as polyetheretherketone (PEEK). The aerosol generating device 10 further comprises a power source 22, e.g., one or more batteries, which may be rechargeable, and a controller 24.

[0052] The heating chamber 18 is open towards the second end 16 of the aerosol generating device 10. In other words, the heating chamber 18 has a first open end 26 towards the second end 16 of the aerosol generating device 10. The heating chamber 18 is typically maintained spaced apart from an interior surface of the body 12 so as to minimize heat transfer to the body 12.

[0053] The aerosol generating device 10 may optionally include a slide cover 28 that is laterally movable between a closed position (see FIG. 1 ) and an open position (see FIG. 2 ), where in the closed position the slide cover 28 covers the first open end 26 of the heating chamber 18 to prevent access to the heating chamber 18, and where in the open position the slide cover 28 exposes the first open end 26 of the heating chamber 18 to provide access to the heating chamber 18. In some embodiments, the slide cover 28 may be biased to the closed position.

[0054] The heating chamber 18, and more particularly the cavity 20, is arranged to receive a correspondingly shaped, generally cylindrical or rod-shaped aerosol-generating article 100. Typically, the aerosol-generating article 100 comprises a pre-packaged aerosol-generating substrate 102. The aerosol-generating article 100 is a disposable and replaceable article (also known as a "consumable") that may, for example, comprise tobacco 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 comprises a mouthpiece segment 108 positioned downstream of the aerosol-generating substrate 102. The aerosol-generating substrate 102 and the mouthpiece segment 108 are coaxially aligned within a wrapper 110 (e.g., a paper wrapper) to hold the components in place to form the rod-shaped aerosol-generating article 100.

[0055] The mouthpiece segment 108 may include one or more of the following components (not shown in detail) arranged in sequence and in coaxial alignment in a downstream direction, i.e., from the distal end 106 towards the proximal (mouth) end 104 of the aerosol-generating article 100: a cooling segment, a central hole segment, and a filter segment. The cooling segment typically includes a hollow paper tube having a thickness greater than that of the wrapper 110. The central hole segment may include a hardening mixture containing cellulose acetate fibers and a plasticizer and serves to increase the strength of the mouthpiece segment 108. The filter segment typically includes cellulose acetate fibers and serves as a mouthpiece filter. As heated steam flows from the aerosol-generating substrate 102 towards the proximal (mouth) end 104 of the aerosol-generating article 100, the steam cools and condenses as it passes through the cooling segment and the central hole segment to form an aerosol having suitable properties for a user to inhale through the filter segment.

[0056] 3 and 4, the heating chamber 18 has a sidewall (or chamber wall) 30 extending between a base 32 located at a second end 34 of the heating chamber 18 and the first open end 26. The sidewall 30 and the base 32 may be connected to one another and integrally formed as a single piece. In the illustrated embodiment, the sidewall 30 is tubular, and more specifically, cylindrical. In other embodiments, the sidewall 30 may have other suitable shapes, such as a tube having an elliptical or polygonal cross section. In yet another embodiment, the sidewall 30 may be tapered.

[0057] In the illustrated embodiment, the base 32 of the heating chamber 18 is closed, e.g., sealed or airtight; i.e., the heating chamber 18 is cup-shaped. This ensures that air drawn in through the first open end 26 is prevented by the base 32 from exiting the second end 34, but is instead guided through the aerosol-generating substrate 102. This also ensures that a user inserts the aerosol-generating article 100 into the heating chamber 18 the intended distance and no further.

[0058] The sidewall 30 of the heating chamber 18 has an inner surface 36 and an outer surface 38. The aerosol generating device 10 comprises first, second, third and fourth inductively heatable susceptors 40, 41, 42, 43 mounted on the inner surface 36 of the sidewall 30 within the cavity 20. In the illustrated embodiment, each of the inductively heatable susceptors 40, 41, 42, 43 is ring-shaped and encloses an angle of 360°. That is, the inductively heatable susceptors 40, 41, 42, 43 comprise a susceptor ring that extends circumferentially around the entire inner surface 36 of the sidewall 30. The inductively heatable susceptors 40, 41, 42, 43 are longitudinally spaced apart within the heating chamber 18 (i.e., they are spaced apart along the longitudinal axis of the heating chamber 18) between the first open end 26 and the second closed end 34. The first, second, third and fourth inductively heatable susceptors 40, 41, 42, 43 define corresponding first, second, third and fourth heating zones 40a, 41a, 42a, 43a within the heating chamber 18, respectively.

[0059] Each of the inductively heatable susceptors 40, 41, 42, 43 has an inner surface, at least a portion of which may be in contact with the aerosol-generating substrate 102. The inductively heatable susceptors 40, 41, 42, 43 may form a friction fit with the aerosol-generating substrate 102, and in particular with the wrapper 110 of the aerosol-generating article 100, and may cause compression of the aerosol-generating substrate 102, as best seen in Figure 2. Compression of the aerosol-generating substrate 102 improves heat transfer through the aerosol-generating substrate 102, for example, by eliminating voids within the aerosol-generating substrate 102.

[0060] The aerosol generating device 10 comprises an induction heating arrangement 46 for heating the aerosol-generating substrate 102. The induction heating arrangement 46 comprises a single generally helical induction coil 48. The induction coil 48 extends helically about the generally cylindrical heating chamber 18. As will be discussed in more detail below, the induction coil 48 can be energized by a power source 22 and a controller 24. The controller 24 includes, among other electronic components, an inverter arranged to convert direct current from the power source 22 to alternating high frequency current for the induction coil 48.

[0061] The sidewall 30 of the heating chamber 18 includes a coil support structure 50 formed on the outer surface 38. In the illustrated embodiment, the coil support structure 50 comprises a coil support groove 52 that extends helically 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 inductively heatable susceptors 40, 41, 42, 43.

[0062] 5, the induction heating arrangement 46 further comprises a plurality of connectors C1, C2, C3, C4, C5 spaced along the longitudinal axis of the heating chamber 18 to define a plurality of longitudinally disposed coil sections L1, L2, L3, L4 of the induction coil 48. Each coil section L1-L4 includes a subset of the total number of turns of the induction coil 48. By way of example only, in the illustrated embodiment, each coil section L1-L4 includes approximately three turns of the induction coil 48. Each coil section L1-L4 is defined by a pair of connectors C1-C5. More specifically, the first coil section L1 is defined by connector pair C1 and C2, the second coil section L2 is defined by connector pair C2 and C3, the third coil section L3 is defined by connector pair C3 and C4, and the fourth coil section L4 is defined by connector pair C4 and C5. It should be noted that providing four coil sections L1-L4 is not essential and more or less than four coil sections L1-L4 can be provided by using an appropriate number of connectors.

[0063] As can be seen from FIG. 5, the first inductively heatable susceptor 40 is positioned adjacent the first coil section L1, the second inductively heatable susceptor 41 is positioned adjacent the second coil section L2, the third inductively heatable susceptor 42 is positioned adjacent the third coil section L3, and the fourth inductively heatable susceptor 43 is positioned adjacent the fourth coil section L4. The controller 24 is configured to selectively energize one or more of the coil sections L1-L4 by providing alternating current to one or more of the coil sections L1-L4 via one or more of the corresponding pairs of electrical connectors C1-C5. This results in preferential heating of the inductively heatable susceptors 40, 41, 42, 43 positioned adjacent each coil section L1-L4, as described in more detail below. The controller has a number of heating modes, each heating mode having an associated section activation pattern (i.e., the sequence or order in which each segment or group of segments is activated). Thus, for operation, the aerosol generating device may selectively activate a selected one of a number of heating modes (which may be preprogrammed or otherwise stored in the memory of the aerosol generating device), and may switch between two or more of these heating modes (e.g., in accordance with user input or depending on the type of aerosol-generating substrate being heated).

[0064] To use the aerosol generating device 10, the user moves the sliding 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 first open end 26 such that the proximal end 104 of the aerosol-generating article 100 is positioned at the first open end 26 of the heating chamber 18 with the aerosol-generating substrate 102 received within the cavity 20 and at least a portion of the mouthpiece segment 108 protruding from the first open end 26 to allow engagement by the user's lips.

[0065] Upon activation of the aerosol generating device 10 by a user, the inductive heating arrangement 46 is energized by the power source 22 and the controller 24. More specifically, according to the present disclosure, the controller 24 is configured to control the inductive heating arrangement 46, in particular the power source 22 and the control circuitry, to supply an alternating current to one or more of the coil sections L1-L4 to selectively energize one or more of the coil sections L1-L4. In some embodiments, when one of the first, second, third, and fourth coil sections L1-L4 is energized, a corresponding first electromagnetic field, a second electromagnetic field, a third electromagnetic field, and a fourth electromagnetic field may be generated. These first, second, third, and fourth electromagnetic fields generated by the corresponding first, second, third, and fourth coil sections L1, L2, L3, L4 may have a corresponding first frequency, a second frequency, a third frequency, and a fourth frequency, respectively. These first, second, third, and fourth frequencies are all different from each other.

[0066] The first, second, third and fourth inductively heatable susceptors 40, 41, 42, 43 have different resonant frequencies. A first electromagnetic field having a first frequency produces preferential heating of the first inductively heatable susceptor 40 (by eddy currents and / or magnetic hysteresis losses generated in the first inductively heatable susceptor 40), thereby causing heat transferred from the first inductively heatable susceptor 40 to produce preferential heating of a first portion of the aerosol-generating substrate 102 positioned in the first heating zone 40a. A second electromagnetic field having a second frequency produces preferential heating of the second inductively heatable susceptor 41 (by eddy currents and / or magnetic hysteresis losses generated in the second inductively heatable susceptor 41), thereby causing heat transferred from the second inductively heatable susceptor 41 to produce preferential heating of a second portion of the aerosol-generating substrate 102 positioned in the second heating zone 41a. The third electromagnetic field having a third frequency produces preferential heating of the third inductively heatable susceptor 42 (by eddy currents and / or magnetic hysteresis losses generated in the third inductively heatable susceptor 42), thereby causing preferential heating of a third portion of the aerosol-generating substrate 102 positioned in the third heating zone 42a with heat transferred from the third inductively heatable susceptor 42. The fourth electromagnetic field having a fourth frequency produces preferential heating of the fourth inductively heatable susceptor 43 (by eddy currents and / or magnetic hysteresis losses generated in the fourth inductively heatable susceptor 43), thereby causing preferential heating of a fourth portion of the aerosol-generating substrate 102 positioned in the fourth heating zone 43a with heat transferred from the fourth inductively heatable susceptor 43. In this manner, selective (or "zonal") heating of first, second, third and fourth portions of the aerosol-generating substrate 102 is achieved in first, second, third and fourth heating zones 40a, 41a, 42a, 43a within the heating chamber 18. Heating of the aerosol-generating substrate 102 by one or more of the first, second, third and fourth inductively heatable susceptors 40, 41, 42, 43 results in heating of the aerosol-generating substrate 102 (or at least a portion thereof) without combustion or burning, and steam is thereby generated.The generated vapor cools and condenses to form an aerosol that can be inhaled by a user of the aerosol generating device 10 through the mouthpiece segment 108, and more particularly through the filter segment.

[0067] In an exemplary first heating mode, the controller 24 can be operable according to a first section activation pattern, where the controller provides alternating current to the first coil section L1 (via connector pair C1 and C2) for a first time period to energize the first coil section L1 and generate a first electromagnetic field (having its first frequency) for the first time period, and thereafter provides alternating current to the second coil section L2 (via connector pair C2 and C3) for a second time period to energize the second coil section L2 and generate a first electromagnetic field (having its first frequency) for the second time period. the third coil section L3 to generate a third electromagnetic field (having the third frequency) during a third time period, thereafter supplying an alternating current to the third coil section L3 (via connector pair C3 and C4) to energize the third coil section L3 and generate a third electromagnetic field (having the third frequency) during a third time period, and thereafter supplying an alternating current to the fourth coil section L4 (via connector pair C4 and C5) to energize the fourth coil section L4 during a fourth time period, thereby generating a fourth electromagnetic field (having the fourth frequency) during a fourth time period. This results in sequential preferential heating of the first, second, third and fourth inductively heatable susceptors 40, 41, 42, 43, and thereby sequential (or "zone-wise" or "partial") heating of the first, second, third and fourth portions of the aerosol-generating substrate 102 positioned in the first, second, third and fourth heating zones 40a, 41a, 42a, 43a, respectively. This heating mode provides progressive heating of the aerosol-generating substrate 102 in a direction from the distal end 106 towards the proximal end 104 of the aerosol-generating article 100, and may provide for a uniform amount of aerosol generation throughout a period of use (e.g., a smoking session).

[0068] In an exemplary second heating mode, the controller 24 can be operable according to a second section activation pattern, where the controller can be configured to simultaneously supply alternating current to the first and second coil sections L1, L2 (via connector pairs C1 and C2 and via connector pairs C2 and C3) during a first time period to energize the first and second coil sections L1, L2 and generate first and second electromagnetic fields (having their first and second frequencies) during the first time period. The controller 24 can then be configured to simultaneously supply alternating current to the third and fourth coil sections L3, L4 (via connector pairs C3 and C4 and via connector pairs C4 and C5) during a second time period to energize the third and fourth coil sections L3, L4 and generate third and fourth electromagnetic fields (having their third and fourth frequencies) during the second time period. This results in simultaneous preferential heating, first, of the first and second inductively heatable susceptors 40, 41 during a first time period, and then in simultaneous preferential heating of the third and fourth inductively heatable susceptors 42, 43 during a second time period, thereby resulting in sequential (or "zone-by-zone" or "partial") heating, first, of the first and second portions of the aerosol-generating substrate 102 positioned in the first and second heating zones 40a, 41a, respectively, of the heating chamber 18, and then of the third and fourth portions of the aerosol-generating substrate 102 positioned in the third and fourth heating zones 42a, 43a, respectively, of the heating chamber 18. This heating mode may provide greater aerosol generation during the first and second time periods, since the two portions of the aerosol-generating substrate 102 are preferentially heated during each of these time periods.

[0069] Vaporization of the aerosol-generating substrate 102 is facilitated by adding air from the surrounding environment, for example, through the first open end 26 of the heating chamber 18, which is heated as it flows between the wrapper 110 and the inner surface 36 of the sidewall 30 of the aerosol-generating article 100, where there may be a space or gap (not shown) between at least a portion of the inner surface of each of the inductively heatable susceptors 40, 41, 42, 43 and the outer surface of the wrapper 110, which defines one or more flow paths from the first open end 26 to the second closed end 34 of the heating chamber 18. More specifically, when a user draws on the filter segment, air is drawn into the heating chamber 18 through the first open end 26, as shown by arrow A in FIG. 2. Air entering the heating chamber 18 flows between the wrapper 110 and the inner surfaces of the inductively heatable susceptors 40, 41, 42, 43 from the first open end 26 to the second closed end 34. When the air reaches the second closed end 34 of the heating chamber 18, it turns 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 towards the proximal (mouth) end 104, as shown by arrow B in FIG.

[0070] Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications can be made to these embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments.

[0071] Any combination of the above-described features in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or clearly contradicted by context.

[0072] Unless the context clearly dictates otherwise, throughout this description and the claims, words like "comprise", "comprising" and the like are to be construed in their inclusive, i.e., "including, but not limited to," sense, as opposed to their exclusive or exhaustive sense.

Claims

1. An aerosol generating device (10), comprising: a heating chamber (18) for receiving at least a portion of the aerosol-generating substrate (102); an induction heating arrangement (46) configured to heat the aerosol-generating substrate (102) to generate an inhalable aerosol, the induction heating arrangement (46) comprising a single induction coil (48) disposed around or near the heating chamber (18); a controller (24) configured to control the induction heating arrangement (46) to supply alternating current to the single induction coil (48); the induction heating arrangement (46) includes a plurality of connectors (C1-C5) associated with the single induction coil (48), the plurality of connectors (C1-C5) being arranged and configured to supply the alternating current to one or more coil sections (L1-L4) of the single induction coil (48) to enable selective energization of the one or more coil sections (L1-L4); the aerosol generating device (10) comprises a plurality of inductively heatable susceptors (40, 41, 42, 43) positioned within the heating chamber (18) adjacent each coil section (L1-L4) so as to define corresponding heating zones (40a, 41a, 42a, 43a) within the heating chamber (18); the aerosol generating device has at least two heating modes, each heating mode having an associated section activation pattern, and the controller is configured to control the induction heating arrangement to supply the alternating current to the one or more coil sections of the single induction coil according to a first section activation pattern when a first heating mode is selected, and to supply the alternating current to the one or more coil sections of the single induction coil according to a second section activation pattern different from the first section activation pattern when a second heating mode is selected. Aerosol generating devices.

2. The aerosol generating device of claim 1, wherein the connectors (C1 to C5) are arranged in pairs so that the alternating current can be supplied to each coil section (L1 to L4) through a corresponding pair of the connectors (C1 to C5).

3. 2. The aerosol generating device of claim 1, wherein the controller (24) is configured to supply the alternating current to each coil section (L1-L4) via a corresponding pair of the connectors (C1-C5).

4. 2. The aerosol generating device of claim 1, wherein the multiple connectors (C1 to C5) are arranged and configured so that, in use, each coil section (L1 to L4) generates an electromagnetic field that is concentrated in a different region of the heating chamber (18) corresponding to the position of an inductively heatable susceptor (40, 41, 42, 43) positioned nearby.

5. 2. The aerosol generating device of claim 1, wherein the single induction coil (48) is a helical coil extending around the heating chamber (18) about a longitudinal axis, and the plurality of connectors (C1-C5) are spaced apart along the longitudinal axis to define longitudinally arranged coil sections (L1-L4).

6. 2. The aerosol generating device of claim 1, wherein in the first section activation pattern, the controller (24) is configured to supply the alternating current to each coil section (L1 to L4) sequentially.

7. 2. The aerosol generating device of claim 1, wherein in the second section activation pattern, the controller (24) is configured to sequentially supply the alternating current to a first subset of coil sections (L1, L2) and then to a second subset of coil sections (L3, L4).

8. 2. The aerosol generating device of claim 1, wherein the controller (24) is configured to control the induction heating arrangement (46) to supply an alternating current to a first coil section (L1) to generate a first electromagnetic field and to supply an alternating current to a second coil section (L2) to generate a second electromagnetic field, the first electromagnetic field having a first frequency and the second electromagnetic field having a second frequency different from the first frequency.

9. 9. The aerosol generating device of claim 8, 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 (41) having a second resonant frequency different from the first resonant frequency.

10. 10. The aerosol generating device of claim 9, wherein the controller (24) is configured to control the induction heating arrangement (46) to supply an alternating current to a third coil section (L3) to generate a third electromagnetic field, the third electromagnetic field having a third frequency different from the first frequency and the second frequency.

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

12. An aerosol generating device as described in any one of claims 1 to 11, wherein the controller (24) is configured to control the induction heating arrangement (46) to heat one or more of the coil sections (L1 to L4) to a first temperature and to heat one or more other of the coil sections (L1 to L4) to a second temperature different from the first temperature.

13. An aerosol generating device as described in claim 12 when dependent on claim 7, wherein the controller is configured to control the induction heating arrangement to heat a first coil section (L1) in the first subset of coil sections (L1, L2) to the first temperature and simultaneously heat a second coil section (L2) in the first subset of coil sections (L1, L2) to the second temperature.

14. An aerosol generation system (1), comprising: an aerosol-generating substrate (102); an aerosol-generating device (10) according to claim 1 for heating the aerosol-generating substrate (102) to generate an aerosol to be inhaled; An aerosol generating system (1) comprising:

15. 15. A method of using an aerosol generating system (1) according to claim 14, comprising the steps of: positioning at least a portion of the aerosol-generating substrate (102) within the heating chamber (18); controlling, by the controller, the induction heating arrangement to supply alternating current to the one or more coil sections of the single induction coil according to a first section activation pattern when a first heating mode is selected; controlling, by the controller, the induction heating arrangement to supply the alternating current to the one or more coil sections of the single induction coil according to a second section activation pattern that is different from the first section activation pattern when a second heating mode is selected; A method comprising:

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