CN121038642A

CN121038642A - Aerosol generation apparatus and related systems and methods

Info

Publication number: CN121038642A
Application number: CN202480029423.8A
Authority: CN
Inventors: O·米洛诺夫; J·P·M·皮嫩伯格; A·M·罗索尔; J·维达尔
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2023-05-02
Filing date: 2024-04-29
Publication date: 2025-11-28
Also published as: WO2024227745A1; KR20260003140A; IL324267A

Abstract

An aerosol-generating device (10, 210) is provided comprising a chamber (16) for receiving at least a portion of an aerosol-generating article (102, 172) comprising an aerosol-forming substrate (104), a heater (50, 52) at least partially surrounding or defining the chamber (16) and configured to provide a heating zone in the chamber (16), and an inductor coil (24) configured to generate an alternating magnetic field in the chamber (16) when the inductor coil (24) is supplied with an alternating current. An associated system (100, 200) and method are also provided.

Description

Aerosol generating device and associated systems and methods

The present disclosure relates to an aerosol-generating device. The present disclosure also relates to an aerosol-generating system comprising the aerosol-generating device and to a method of controlling the aerosol-generating device.

Some known aerosol-generating systems comprise an aerosol-generating device and an aerosol-generating article comprising an aerosol-forming substrate. In use, the aerosol-generating device heats an aerosol-forming substrate of an aerosol-generating article to form an aerosol.

Some known aerosol-generating devices comprise an internal heater for heating the aerosol-forming substrate from within, such as a heating blade which in use penetrates the aerosol-forming substrate and heats the aerosol-forming substrate from within. However, using an internal heater to sufficiently heat an outer portion of the aerosol-forming substrate to form an aerosol may require the internal heater to be heated to a sufficiently high temperature that there is a risk of the internal heater overheating or burning an inner portion of the aerosol-forming substrate in proximity to the internal heater. Thus, the use of an internal heater generally results in the outer portion of the aerosol-forming substrate furthest from the internal heater during use not being heated to a sufficiently high temperature to form an aerosol. This means that the outer part of the aerosol-forming substrate is generally wasted.

Some known aerosol-generating devices comprise an external heater for heating the aerosol-forming substrate from outside the aerosol-forming substrate, such as a tubular heating element which in use receives a portion of the aerosol-generating article and heats the aerosol-forming substrate from outside. However, using an external heater to sufficiently heat an inner portion of the aerosol-forming substrate to form an aerosol may require the heater to be heated to a sufficiently high temperature that there is a risk that the external heater will overheat or burn an outer portion of the aerosol-forming substrate in close proximity to the heater. Thus, the use of an external heater typically results in the interior portion of the aerosol-forming substrate furthest from the heater during use not being heated to a sufficiently high temperature to form an aerosol. This means that the inner part of the aerosol-forming substrate is generally wasted.

It is an object of the present invention to provide an improved aerosol-generating device, system and method of controlling or heating.

According to the present disclosure, an aerosol-generating device is provided. The aerosol-generating device may comprise a chamber or cavity for receiving at least a portion of the aerosol-generating article. The aerosol-generating article may comprise an aerosol-forming substrate. The aerosol-generating device may comprise a heater. The heater may at least partially surround or define a chamber or cavity. The heater may be configured to provide a heating zone in the chamber. The aerosol-generating device may comprise an inductor coil configured to generate an alternating magnetic field in the chamber when the inductor coil is supplied with an alternating current.

Thus, according to a first aspect of the present disclosure there is provided an aerosol-generating device comprising a chamber for receiving at least a portion of an aerosol-generating article comprising an aerosol-forming substrate, a heater at least partially surrounding or defining the chamber and configured to provide a heating zone in the chamber, and an inductor coil configured to generate an alternating magnetic field in the chamber when the inductor coil is supplied with an alternating current. The chamber may be a cavity or may be referred to as a cavity.

Advantageously, the aerosol-generating device comprises a heater at least partially surrounding or defining the chamber, and an inductor coil configured to generate an alternating magnetic field in the chamber. The aerosol-generating article may be removably received in the chamber. In use, the heater may heat the aerosol-forming substrate of the received aerosol-generating article from the outside and the inductor coil may inductively heat a susceptor located inside the aerosol-forming substrate. Thus, advantageously, the aerosol-generating device may allow for simultaneous, partially simultaneous or sequential heating of the aerosol-forming substrate from the outside and from the inside. This may advantageously enable both the inner and outer portions of the aerosol-forming substrate to be heated sufficiently to form an aerosol, while reducing the risk of overheating the heater or burning a portion of the aerosol-forming substrate.

For the avoidance of doubt, reference herein to a heater configured to provide a heating zone should not be interpreted to mean that the heating zone is heated by the heater alone in use. Other components such as susceptors discussed later may provide heat to the heating zone in use.

References herein to systems, devices, articles and substrates may refer to aerosol-generating systems, aerosol-generating devices, aerosol-generating articles and aerosol-forming substrates, respectively.

The aerosol-generating system may comprise a susceptor. Optionally, the article comprises a susceptor. In this case, the susceptor may be in the aerosol-forming substrate of the article. Optionally, the susceptor is separate from the device and the article. In this case, the susceptor may be insertable into the aerosol-forming substrate prior to use, or may be attachable to the device prior to use. Optionally, the device comprises a susceptor. In this case, the susceptor may be configured to penetrate the article received in the chamber.

The susceptor may be shaped as a pin, vane or bar. The chamber may comprise an open first end through which at least a portion of the aerosol-generating article may optionally be inserted into the chamber. Optionally, the chamber comprises an at least partially closed second end or an at least partially closed base, optionally opposite the open first end. The susceptor may for example protrude into the chamber from the base towards the open end.

The susceptor may be attachable to and detachable from the aerosol-generating device, for example using clips, threads, snap-fits, or any other suitable attachment means. The susceptor may be attachable to and detachable from the chamber (e.g., the base of the chamber), e.g., to protrude into the chamber, optionally from the base toward the open end. Advantageously, this may allow the susceptor to be removed for cleaning or disposal.

The aerosol-generating system may comprise a plurality of susceptors. The aerosol-generating article may comprise a plurality of susceptors. The aerosol-generating device may comprise a plurality of susceptors. As will be appreciated by the skilled person after reading this disclosure, features described in relation to the susceptor or the susceptor may be applicable to one or more or each of a plurality of susceptors. Thus, references herein to a susceptor or to the susceptor may be considered to be references to one or more susceptors.

In use, when supplied with an alternating current, the inductor coil may generate an alternating magnetic field in the chamber. The alternating current supplied to the inductor coil may be a high frequency alternating current. For the purposes of this disclosure, the term "high frequency" may refer to frequencies ranging from 1 megahertz to 30 megahertz, preferably 1 megahertz to 10 megahertz, more preferably 5 megahertz to 7 megahertz. In use, the alternating magnetic field may cause eddy currents and hysteresis losses in the susceptor located in the chamber and thus cause heating of the susceptor. Thus, in use, the inductor coil may inductively heat the susceptor. In use, the susceptor may then heat the aerosol-forming substrate, for example from inside the aerosol-forming substrate. This may be the case whether the susceptor is part of the article and is located within the aerosol-forming substrate, or the susceptor is part of the device and penetrates the aerosol-forming substrate when the article is received in the chamber.

The susceptor, which may also be referred to as susceptor element, may comprise or consist of one or more susceptor materials.

Suitable susceptor materials may include, but are not limited to, carbon-based materials, graphene, graphite, expanded graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel-containing compounds, composites of titanium and metallic materials. Suitable susceptor materials may include ferromagnetic materials, such as ferritic iron, ferromagnetic alloys (such as ferromagnetic steel or stainless steel), ferromagnetic particles, and ferrites. The susceptor material may comprise more than 5%, preferably more than 20%, more preferably more than 50% or more than 90% of ferromagnetic or paramagnetic material. Preferred susceptor materials may comprise metals, metal alloys or carbon.

Optionally, the device comprises at least one power source. Any reference herein to a power source should be construed as a reference to at least one power source. Optionally, the apparatus comprises a controller. Optionally, the controller is configured to independently control the supply of power from the at least one power source to the heater and the supply of power from the at least one power source to the inductor coil. Advantageously, independently controlling the supply of power to the heater and the supply of power to the inductor coil may allow for independently controlling the temperature of the heater and the temperature of the susceptor in the chamber inductively heated by the alternating magnetic field generated by the inductor coil.

Optionally, the apparatus comprises a first power source and a second power source different from the first power source. Optionally, the controller is configured to independently control the supply of power from the first power source to the heater and the supply of power from the second power source to the inductor coil. Advantageously, the use of the first and second power sources may simplify independent control of the power supply to the heater and inductor coils.

Optionally, the controller is configured to identify at least one maintenance phase during use of the device. The or each maintenance phase may correspond to or include a phase during which the user does not draw on the device or the article received in the chamber. Optionally, the controller is configured to identify at least one suction phase during use of the device. The or each suction phase may correspond to or include a phase during which a user is sucking on the device or article received in the chamber. Advantageously, as will be discussed in more detail later, the identification maintenance phase and the suction phase may allow optimizing the control of the power supply to the heater and the inductor coil during these phases. The suction phase may be referred to as a suction phase.

The use of the device may include multiple maintenance phases and multiple aspiration phases. Optional features described herein for the sustain phases may be applied to each sustain phase of the plurality of sustain phases. Optional features described herein for the aspiration phase may be applied to each of the plurality of aspiration phases.

Optionally, the controller is configured to control the supply of power from the at least one power source to one or both of the heater and the inductor coil during the maintenance phase.

During the maintenance phase, the controller may be configured to control the supply of power from the at least one power source to one or both of the inductor coil and the heater to maintain the temperature of the heating zone below the aerosolization temperature of the aerosol-forming substrate. Advantageously, this may preserve the aerosol-forming substrate for other phases of aerosol formation desired.

Reference herein to the temperature of the heating zone may refer to the temperature at any point in the heating zone, or to the temperature at a substantially central point in the heating zone, or to the average temperature in the heating zone, or to the maximum temperature at any point in the heating zone.

Optionally, during the maintenance phase, the controller is configured to control the supply of electrical power from the at least one power source to one or both of the inductor coil and the heater to maintain the temperature of the heating zone within a heating zone maintenance temperature range. Optionally, the heating zone maintains a temperature range having an upper limit that is less than the temperature required for the aerosol-forming substrate to form an aerosol. Optionally, the heating zone maintenance temperature range has an upper limit of no more than 250, 200, or 170 degrees celsius. Optionally, the heating zone maintenance temperature range has a lower limit of at least 50, 100, or 140 degrees celsius. Optionally, the heating zone maintains a temperature range between 50 to 250, 50 to 200, 50 to 170, 100 to 250, 100 to 200, 100 to 170, 140 to 250, 140 to 200, or 140 to 170 degrees celsius. Advantageously, such temperatures may be low enough to avoid the formation of large amounts or any aerosols from the aerosol-forming material of the aerosol-forming substrate, but high enough to allow further heating of the aerosol-forming substrate, for example to rapidly or instantaneously exceed the aerosol-forming temperature of the aerosol-forming material, to rapidly generate an aerosol when desired. As will be appreciated by the skilled person after reading this disclosure, references herein to heating an aerosol-forming substrate to form an aerosol may be regarded as references to heating an aerosol-forming material of the aerosol-forming substrate to form an aerosol. Not all components or materials of the aerosol-forming substrate need be heatable to form an aerosol. Indeed, in use, some components or materials of the aerosol-forming substrate may be heated to form an aerosol, and other components or materials may not be heated to form an aerosol.

Optionally, during the maintenance phase, the controller is configured to control the supply of electrical power from the at least one power source to the heater to maintain the temperature of the heater within a heater maintenance temperature range. The optional features discussed above with respect to the heating zone maintenance temperature range apply equally to the heater maintenance temperature range. Thus, the heater maintenance temperature range may have one or more of an upper limit less than the temperature required by the heater to sufficiently heat the aerosol-forming material of the aerosol-forming substrate to form an aerosol, an upper limit of no more than 250, 200 or 170 degrees celsius, and a lower limit of at least 50, 100 or 140 degrees celsius. The heater maintenance temperature range may be between 50 to 250, 50 to 200, 50 to 170, 100 to 250, 100 to 200, 100 to 170, 140 to 250, 140 to 200, or 140 to 170 degrees celsius. Advantageously, such temperatures may be low enough to avoid forming large amounts or any aerosols formed from the aerosol-forming material of the aerosol-forming substrate, but high enough to allow further heating of the aerosol-forming substrate to rapidly generate aerosols when desired.

Optionally, during the maintenance phase, the controller is configured not to supply power from the at least one power source to the inductor coil. Advantageously, this may save power during the maintenance phase when heating the susceptor is not required to heat the aerosol-forming substrate to form an aerosol. For the avoidance of doubt, reference to controlling the supply of power to the inductor coil may include not supplying power to the inductor coil.

Alternatively, during the maintenance phase, the controller may be configured to control the supply of electrical power from the at least one power source to the inductor coil to maintain the temperature of the susceptor in the chamber within a susceptor maintenance temperature range. The optional features discussed above with respect to the heating zone maintenance temperature range apply equally to the susceptor maintenance temperature range. Thus, the susceptor maintenance temperature range may have one or more of an upper limit less than the temperature required by the susceptor to sufficiently heat the aerosol-forming substrate to form an aerosol, an upper limit of no more than 250, 200 or 170 degrees celsius, and a lower limit of at least 50, 100 or 140 degrees celsius. The susceptor maintenance temperature range may be between 50 to 250, 50 to 200, 50 to 170, 100 to 250, 100 to 200, 100 to 170, 140 to 250, 140 to 200, or 140 to 170 degrees celsius. Advantageously, such temperatures may be low enough to avoid the formation of large amounts or any aerosols from the aerosol-forming material of the aerosol-forming substrate, but high enough to allow further heating of the aerosol-forming substrate to rapidly generate aerosols when desired.

Optionally, the device is configured to detect one or more user puffs, for example during a use procedure. Such suction may be suction performed on the device or on the article received in the chamber. The device may include a suction detection mechanism for detecting one or more user suction. The suction detection mechanism may include at least a portion of the controller, or the controller may be utilized. Advantageously, this may allow for control of heating based on when the user is sucking.

The terms "aspirate," "user aspirate," "aspirate conducted," and the like may all be used synonymously herein. These terms may all be used to refer to a user inhaling on a device or article. Each reference to suction may be considered as a reference to suction during the course of use.

The maintenance phase may be a period during which the user is not sucking on the device or article. The maintenance phase may be a period of time during which the device or system is in an idle state, optionally ready for aspiration or inhalation. The suction phase may be a period during which a user is sucking on a system (e.g., a device or article).

Optionally, the device (e.g., a suction detection mechanism of the device) includes a pressure sensor. Optionally, the device (e.g., a suction detection mechanism of the device) includes a flow restrictor, such as a venturi. Optionally, the pressure sensor is configured to sense a pressure of the airflow through the flow restrictor. The device may include a device air inlet. The device may include a device air outlet. The device may include a device airflow path. The device air flow path may connect the device air inlet to the device air outlet. In use, in response to a user drawing on the device or an article received in a chamber of the device, air may flow through the device air inlet, through the device air flow path, and then through the device air outlet. The flow restrictor may be positioned in the device airflow path. The flow restrictor may comprise a restriction in the cross-sectional area of the device airflow path, for example compared to the cross-sectional area of the air inlet. Advantageously, the flow restrictor may cause an increase in the airflow velocity through the airflow path of the device as the airflow travels through the flow restrictor. Thus, advantageously, for a given suction, a greater pressure drop can be observed within the flow restrictor. This may advantageously allow a pressure sensor configured to detect pressure in the flow restrictor to detect weaker suction, and may allow the pressure sensor to more accurately determine the airflow rate through the device.

Optionally, the pump detection mechanism is configured to detect pump by monitoring a change in one or both of power supplied to the at least one pump detection heater and temperature of the at least one pump detection heater. The at least one suction detection heater may be or include one or both of an internal heater and an external heater. At least one suction detection heater may be in the airflow path. In use, during pumping, air may flow past the at least one suction detection heater. This may be used to cool at least one suction detection heater. This may mean that the temperature of the at least one suction detection heater decreases, or that an increase in power supplied to the at least one suction detection heater is required to maintain its temperature. Such a decrease in temperature or an increase in supplied power may indicate that the user is drawing on the system and may thus allow the draw detection mechanism to detect a draw. This way of detecting suction is explained in more detail in for example WO2013098397, the content of which is incorporated herein.

Optionally, the device (e.g. a suction detection mechanism of the device) is configured to detect the onset of one or each user suction made during the course of use. Optionally, the device (e.g. a suction detection mechanism of the device) is configured to detect the end of one or each user suction made during the course of use. Advantageously, being able to detect the start and end of a user's draw may allow the device to switch accurately between the maintenance phase and the draw phase depending on when the user is drawing.

Optionally, the device (e.g., a suction detection mechanism of the device) is configured to determine or estimate the duration of one or each suction made during the course of use. Optionally, the device (e.g., a suction detection mechanism of the device) is configured to determine or estimate the duration of suction so far. This may be accomplished by determining or estimating the duration of the suction so far, either continuously or at one or more points in time (e.g. at a point in time of a period of time after the start of the suction).

Optionally, the device (e.g. a suction detection mechanism of the device) is configured to determine or estimate the volume of at least a portion of one or each suction made during the course of use, e.g. the total volume from start to end. For example, for one or each aspiration, the device (e.g., the aspiration detection mechanism of the device) may be configured to determine the volume of the aspiration so far, either continuously or at one or more points in time (e.g., a point in time of a period of time after the onset of aspiration). As will be appreciated by the skilled artisan upon reading this disclosure, the volume of draw may refer to the volume of airflow through the device as a result of a user drawing on the device or article.

Optionally, the device (e.g., a suction detection mechanism of the device) is configured to measure, determine or estimate one or more instantaneous flow rates of the air flow resulting from one or each suction made during the course of use. For example, for one or each aspiration, the device (e.g., an aspiration detection mechanism of the device) may be configured to determine the flow rate of the airflow generated by the aspiration continuously or at one or more points in time (e.g., a point in time of a period of time after the onset of aspiration). In this context, unless otherwise indicated, the term "flow rate" may refer to a flow rate that is measurable in meters per second or a volumetric flow rate that is measurable in cubic meters per second. Features described with respect to flow rates may be applied to one or both of a flow rate measurable in meters per second and a volumetric flow rate measurable in cubic meters per second.

The device or suction detection mechanism may comprise a flow meter. The flow meter may be configured to measure, determine or estimate one or more instantaneous flow rates of the airflow resulting from one or each suction made during the use process. As described above, the flow rate may refer to one or both of a flow rate measurable in meters per second and a volumetric flow rate measurable in cubic meters per second.

The flow meter may be or include any suitable type of flow meter, such as a turbine flow meter. An example of a turbine flow meter is shown in WO 2022184510. Such a turbine flow meter or any other suitable flow meter may be used in the present apparatus and coupled to the controller to provide the controller with an estimate of one or both of a flow rate measurable in meters per second and a volumetric flow rate measurable in cubic meters per second. For turbine flowmeters, this may be based on the angular velocity or rotational speed of the turbine. As another example, the flow meter may include a pressure sensor or the pressure sensor. The pressure sensor may be coupled to the controller and configured to provide an estimate of one or both of a flow rate measurable in meters per second and a volumetric flow rate measurable in cubic meters per second to the controller based on the sensed pressure. Air flowmeters are commercially available and after reading this disclosure, the skilled person will be able to implement a suitable flowmeter into the device.

Optionally, the device (e.g. a suction detection mechanism of the device) is configured to determine or estimate the instantaneous rate of change of the flow rate of the airflow caused by one or each suction made during the course of use. For example, for one or each aspiration, the device (e.g., an aspiration detection mechanism of the device) may be configured to determine the rate of change of the flow rate of the airflow generated by the aspiration continuously or at one or more points in time (e.g., a point in time of a period of time after the onset of aspiration).

Optionally, the controller is configured to perform one or both of ending the maintenance phase and starting the aspiration phase upon detecting the aspiration or the start of aspiration. Optionally, the controller is configured to adjust (e.g. increase) one or both of the power supply to the heater and the power supply to the inductor coil upon detection of the suction or the start of suction. Advantageously, this may allow the device to respond quickly to user suction and generate an aerosol accordingly.

Optionally, the controller is configured to perform one or both of an end suction phase and a start maintenance phase upon detecting the end of suction. Optionally, the controller is configured to adjust (e.g. reduce) one or both of the supply of power to the heater and the supply of power to the inductor coil upon detection of the end of the draw. Advantageously, this may allow the device to quickly respond to the end of a user's inhalation and accordingly cease generating aerosols. Reverting to the maintenance phase may advantageously allow the device to keep the aerosol-forming substrate warm so as to reduce the time required to generate aerosol in response to detecting the start of the next inhalation.

Optionally, in response to detecting the draw, the controller is configured to adjust (e.g., increase) the supply of power from the at least one power source to one or both of the inductor coil and the heater to adjust (e.g., increase) the temperature of the heating zone, e.g., to above the aerosolization temperature of the aerosol-forming material of the aerosol-forming substrate or to within a heating zone draw temperature range. Optionally, the heating zone extraction temperature range has a lower limit of at least 200, 250, or 300 degrees celsius. Optionally, the heating zone extraction temperature range has an upper limit of no more than 800, 650, or 500 degrees celsius. Optionally, the heating zone extraction temperature ranges between 200 to 800, or 200 to 650, or 200 to 500, or 250 to 800, or 250 to 650, or 250 to 500, or 300 to 800, or 300 to 650, or 300 to 500 degrees celsius. Advantageously, such an increase in the temperature of the heating zone, which may occur during the extraction phase, may result in the aerosol-forming material of the aerosol-forming substrate in the heating zone being heated to form a desired amount of aerosol of a desired composition.

Optionally, in response to detecting the draw, the controller is configured to adjust (e.g., increase) the supply of power from the at least one power source to the inductor coil. Optionally, in response to the device (e.g., a suction detection mechanism of the device) detecting suction, the controller is configured to adjust (e.g., increase) the supply of power from the at least one power source to the inductor coil to increase the temperature of the susceptor, e.g., to increase the susceptor suction temperature range. The susceptor suction temperature range may have a lower limit above the aerosolization temperature of the aerosol-forming material of the aerosol-forming substrate. The susceptor pull temperature range may have a lower limit of at least 200, 250, or 300 degrees celsius. The susceptor pull temperature range may have an upper limit of no more than 800, 650, or 500 degrees celsius. The susceptor pull temperature may range between 200 to 800, or 200 to 650, or 200 to 500, or 250 to 800, or 250 to 650, or 250 to 500, or 300 to 800, or 300 to 650, or 300 to 500 degrees celsius. The temperature of the susceptor may be increased to a sufficiently high temperature so that the susceptor heats the aerosol-forming substrate to form an aerosol.

Optionally, the controller is configured not to adjust the supply of power from the at least one power source to the heater in response to detecting the draw. Optionally, in response to detecting the draw, the controller is configured to control the supply of power from the at least one power source to the heater in the same manner as during the maintenance phase. Optionally, in response to detecting the draw, the controller is configured to control the supply of power from the at least one power source to the heater to maintain the temperature of the heater within a heater draw temperature range. Optionally, the heater suction temperature range is the same as the heater maintenance temperature range. Optionally, the heater extraction temperature range has an upper limit of no more than the aerosolization temperature of the aerosol-forming material of the aerosol-forming substrate, or no more than 250, 200, or 170 degrees celsius. Optionally, the heater soak temperature range has a lower limit of at least 50, 100, or 140 degrees celsius. Optionally, the heater soak temperature ranges between 50 to 250, 50 to 200, 50 to 170, 100 to 250, 100 to 200, 100 to 170, 140 to 250, 140 to 200, 140 to 170 degrees celsius. Advantageously, this may save power, as the susceptor, rather than the heater, may be primarily responsible for aerosol generation during the extraction phase. Susceptors rather than heaters may be preferred to take this responsibility, as susceptors may be more likely to be in closer thermal contact with the aerosol-forming substrate and thus be able to generate an aerosol quickly and efficiently. When rapid heating of the aerosol-forming substrate or heating zone is required, it may be preferable to heat the susceptor rather than the heater, as the susceptor may be able to heat the aerosol-forming substrate or heating zone faster than the heater.

Alternatively, the controller may be configured to adjust (e.g. increase) the supply of power from the at least one power source to the heater in response to detecting the draw. In this case, the heater suction temperature range may have one or more of a lower limit above the aerosolization temperature of the aerosol-forming substrate, a lower limit of at least 200, 250 or 300 degrees celsius, and an upper limit of no more than 800, 650 or 500 degrees celsius. The heater soak temperature may range between 200 to 800, or 200 to 650, or 200 to 500, or 250 to 800, or 250 to 650, or 250 to 500, or 300 to 800, or 300 to 650, or 300 to 500 degrees celsius. Advantageously, in this case, more aerosol can be generated more quickly during the suction phase than if the heater is not heated to a great extent during the suction phase.

The controller may be configured to adjust (e.g., increase) one or both of the supply of power to the heater and the supply of power to the inductor coil based on the device detecting, determining, or estimating any one or more of:

suction or start of suction;

The duration of the suction so far reached (e.g. increased above) the first threshold (e.g. to ensure that the detected airflow is suction, rather than a brief non-suction related airflow, such as an airflow caused by a brief movement of the device or wind);

Reaching (e.g., increasing above) the first threshold volume of suction so far (e.g., to ensure that the detected airflow is suction, not a small volume of non-suction related airflow);

The instantaneous flow rate of the air flow resulting from the suction (e.g., to ensure that the detected air flow is suction, not a small non-suction related air flow) reaches (e.g., increases above) a first threshold;

maintaining the instantaneous flow rate of the air flow resulting from the suction above the first threshold for at least a first period of time (e.g., to ensure that the detected air flow is suction, rather than a small and brief non-suction related air flow);

The instantaneous rate of change of the flow rate of the air flow resulting from the suction (e.g., indicating that the detected air flow increases at a sufficient rate to indicate that it is suction and not a small non-suction related air flow) reaches (e.g., increases above) a first threshold;

Maintaining a transient rate of change of the flow rate of the airflow resulting from the suction above a first threshold for at least a first period of time (e.g., indicating that the detected airflow has increased at a sufficient rate for a sufficient duration to indicate that it is suction, not a small non-suction related airflow);

a temperature of the heating zone or heater that decreases below the lower threshold (e.g., indicating that the flow rate has increased and thus the cooling effect of the air stream has increased such that the temperature of the heating zone or heater decreases and thus indicates that suction is being performed, e.g., as explained in WO2013098397, the contents of which are incorporated herein), and

Maintaining the temperature of the heating zone or heater below the lower threshold for at least a first period of time (e.g., indicating that the flow rate has increased and thus the cooling effect of the airflow has increased, resulting in a decrease in the temperature of the heating zone or heater and thus an indication that suction is being performed).

One or both of the end of the maintenance phase and the start of the pull phase may occur in response to or an amount of time after the device detects, determines or estimates any one or more of the bullets in the previous paragraph.

The controller may be configured to adjust (e.g., reduce) one or both of the supply of power to the heater and the supply of power to the inductor coil based on the device detecting, determining, or estimating any one or more of:

ending suction;

The duration of the suction up to date reaching (e.g., increasing above) the second threshold (e.g., indicating that suction may end soon);

The volume of the suction up to date reaching (e.g., increasing above) the second threshold (e.g., indicating that suction may end soon);

The instantaneous flow rate of the air flow resulting from the suction reaching (e.g., decreasing below) the second threshold (e.g., decreasing from above the second threshold to below the second threshold, indicating that suction may end soon);

Maintaining the instantaneous flow rate of the air flow resulting from the suction below a second threshold for at least a second period of time (e.g., indicating that suction may end soon);

The instantaneous rate of change of the flow rate of the airflow resulting from the suction reaching (e.g., decreasing below) a second (optionally negative) threshold (e.g., indicating that the flow rate decreases fast enough to indicate that suction may end soon);

maintaining an instantaneous rate of change of the flow rate of the airflow resulting from the suction below a second (optionally negative) threshold for at least a second period of time (e.g., indicating that the flow rate has decreased fast enough for a sufficient duration to indicate that suction may end soon);

Increasing the temperature of the heating zone or heater above the upper threshold (e.g., indicating that the flow rate has decreased, and thus the cooling effect of the air flow has decreased to allow the temperature of the heating zone or heater to increase, and thus indicating that suction may end soon), and

Maintaining the temperature of the heating zone or heater above the upper threshold for a period of time (e.g., indicating that the flow rate has been reduced and thus the cooling effect of the airflow has been reduced to allow the temperature of the heating zone or heater to increase and thus indicate that the draw may end soon).

One or both of the end sucking phase and the start maintaining phase may occur in response to or a predetermined amount of time after the device detects, determines or estimates any one or more of the bullets in the previous paragraph.

Optionally, the heater is configured to heat one or both of the heating zone and the article received in the chamber. Optionally, the heater (e.g., an inner surface of the heater) is configured to contact the article when the article is at least partially received in the chamber. Advantageously, this may improve heat transfer from the heater to the article.

The heater may include a coating. The coating may be a protective coating. The coating may be a thermally conductive coating. The coating may be present on the inner surface of the heater. When the article is at least partially received in the chamber, it contacts a coating of the article, which may be a heater. Advantageously, the coating may protect the heater and may improve heat transfer from the heater to the article.

Optionally, the heater is substantially tubular. The chamber may be right cylindrical. Optionally, the heater defines or at least partially surrounds the chamber. Optionally, the heater surrounds the chamber. Advantageously, this may allow heat from the heater to be transferred from the entire circumference of the article to the article.

Optionally, the heater is or comprises an infrared radiation based heating element, a photon source or a resistive heating element. Preferably, the heater is or comprises a resistive heater. The heater may include an electrically insulating substrate (e.g., a substantially tubular electrically insulating substrate), and resistive tracks on the electrically insulating substrate. The device may be configured such that in use current is passed through the resistive track. This may be resistive heating or joule heating the resistive track.

Suitable electrically insulating materials for electrically insulating substrates for resistive heaters, for example, may include one or more of glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may comprise mica, alumina or zirconia.

Suitable resistive materials for resistive tracks of resistive heaters may include, for example, one or more of semiconductors such as doped ceramics, resistive ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys, and composites made of ceramic materials and metal materials. Such composite materials may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing alloys, cobalt-containing alloys, chromium-containing alloys, aluminum-containing alloys, titanium-containing alloys, zirconium-containing alloys, hafnium-containing alloys, niobium-containing alloys, molybdenum-containing alloys, tantalum-containing alloys, tungsten-containing alloys, tin-containing alloys, gallium-containing alloys, manganese-containing alloys, and iron-containing alloys, and superalloys based on nickel, iron, cobalt, stainless steel, timetal, and iron-manganese-aluminum-based alloys. The resistive track may comprise a heating wire or filament, such as a Ni-Cr (nickel-chromium), platinum, tungsten or alloy wire or filament.

Optionally, the heater (e.g., an electrically insulating substrate of the heater) comprises or consists of a thermally conductive material. Advantageously, this may make the temperature of the heater more uniform.

Optionally, the heater is substantially transparent to an alternating magnetic field generated by the inductor coil when the inductor coil is supplied with alternating current. This property may be referred to as the heater being "substantially magnetically transparent". This may be particularly advantageous in case at least a portion of the heater is between the inductor coil and the chamber, for example in case the inductor coil surrounds the heater and the heater defines or surrounds the chamber.

The heater being substantially transparent to the alternating magnetic field generated by the inductor coil when the inductor coil is supplied with an alternating current may mean that the presence of the heater does not reduce the heating of the susceptor measured in joules by more than 10% or 5% (compared to the same device except for omitting the heater) during use of the aerosol-generating device to generate an aerosol from the aerosol-forming substrate. More specifically, the heater being substantially transparent to the alternating magnetic field generated by the inductor coil when the inductor coil is supplied with alternating current may mean that during use of the aerosol-generating device to generate an aerosol from an aerosol-forming substrate, for example under standard operating conditions, with alternating current supplied to the inductor coil at a resonant (maximum susceptor heating) frequency, the presence of the heater does not reduce the heating of the susceptor measured in joules by more than 10% or 5% (compared to otherwise identical devices except for omitting the heater). Thus, advantageously, the transparency of the heater may correspond to a minimum absorption of power supplied to the inductor coil by the heater.

During one or both of the sustain phase and the pump phase, the controller may be configured to supply an alternating current to the inductor coil. The frequency or frequencies of the alternating current supplied to the inductor coil may be selected such that the heater has no or little effect on the alternating magnetic field generated by the inductor coil when the inductor coil is supplied with alternating current.

Optionally, the heater comprises, or consists of, for example, at least 90% by weight of a substantially non-ferromagnetic material. Optionally, the heater comprises, or consists of, for example, at least 90% by weight of the substantially paramagnetic material. Optionally, the heater comprises or consists of, for example, at least 90% by weight of a substantially diamagnetic material. Optionally, the heater comprises or consists of, for example, at least 90% by weight of a substantially paramagnetic and diamagnetic material. Optionally, the heater comprises, for example, at least 90 wt% austenitic steel, such as austenitic stainless steel.

For the avoidance of doubt, the term "ferromagnetic" may refer to materials that are generally considered to exhibit strong attraction to magnets, the term "paramagnetic" may refer to materials that are generally considered to exhibit weak attraction to magnets, and the term "diamagnetic" may refer to materials that are generally considered to exhibit weak or strong repulsion to magnets. The terms paramagnetic and diamagnetic herein are intended to include materials that exhibit extremely weak, negligible, or even no observable interactions with magnetic fields, and thus include materials that are generally considered non-magnetic.

The heater may comprise or consist of, for example, at least 90% by weight of a material having a relative magnetic permeability close to 1, for example, a maximum relative magnetic permeability of no more than 2, 1.5 or 1.1. The heater may comprise or consist of, for example, at least 90 wt% of a material having a maximum relative permeability of at least 0.99, 0.999 or 1. The relative permeability compares the permeability of the material with the permeability of free space. Since magnetic permeability varies with magnetic field strength, the "maximum relative magnetic permeability" is used. Any reference herein to permeability refers to permeability at 20 degrees celsius and 50% relative humidity. Advantageously, a material having a relative permeability close to 1 may minimize the amount of power supplied to the inductor coil that is dissipated in the heater.

The heater may comprise or consist of, for example, at least 90 wt% of a material having a conductivity of less than 0.8 x 10 ⁴ or 0.8 x 10 ³ or 0.8 x 10 ² siemens/meter in at least one direction (e.g., in all directions) at 20 degrees celsius and 50% relative humidity. Advantageously, a material with high resistivity may minimize eddy currents induced by the presence of an alternating magnetic field and thus minimize the amount of power supplied to the inductor coil that is dissipated in the heater.

Thus, a relative permeability close to 1 and a low electrical conductivity can work cooperatively to minimize the amount of power supplied to the inductor coil that is dissipated in the heater. Thus, it may be particularly advantageous for the heater to comprise, or consist of, for example at least 90% by weight of a material having one or more or all of the following at 20 degrees celsius and 50% relative humidity:

A maximum relative permeability of no more than 2, 1.5 or 1.1;

a maximum relative permeability of at least 0.99, 0.999 or 1, and

A conductivity of less than 0.8 x 10 ⁴ or 0.8 x 10 ³ or 0.8 x 10 ² siemens/meter in at least one direction (e.g., in all directions). It may be particularly preferred that the heater comprises or consists of, for example, at least 90 wt% of a material having a maximum relative permeability between 0.99 and 2, preferably between 0.99 and 1.5, at 20 degrees celsius and 50% relative humidity, and optionally an electrical conductivity of less than 0.8 x 10 ⁴, preferably less than 0.8 x 10 ³ siemens/meter in at least one direction (e.g. in all directions). As set forth above, advantageously, a relative permeability of approximately 1 and a low electrical conductivity may work cooperatively to minimize the amount of power supplied to the inductor coil that is dissipated in the heater.

Optionally, the heater comprises a ceramic material. Where the heater comprises a ceramic material, the ceramic material may act as an electrically insulating substrate for the resistive track (as discussed previously).

Optionally, the heater comprises a polymer composite. Optionally, the polymer composite is substantially magnetically transparent, for example, to provide a substantially magnetically transparent heater as discussed above. Optionally, the polymer composite comprises a polymeric material, such as at least one polymeric material selected from the list consisting of Polyetheretherketone (PEEK) and Liquid Crystal Polymer (LCP). Optionally, the polymer composite comprises at least one of graphite, graphite-derived materials (such as expanded graphite or graphite nanoplates), graphite-based materials, and hexagonal boron nitride. Optionally, the polymer composite comprises a polymer material and at least one of graphite, graphite-derived material (such as expanded graphite or graphite nanoplates) and hexagonal boron nitride dispersed within the polymer material. The polymeric material may be a polymeric matrix. At least one of graphite, graphite derived materials (such as expanded graphite or graphite nanoplates) and hexagonal boron nitride may be present in the form of particles, and may be referred to as filler particles. Optionally, the heater comprises the polymeric material in an amount between 22% and 33% by weight of the heater. Optionally, the heater comprises at least one of graphite, graphite-derived material, and hexagonal boron nitride in an amount between 62% and 69% by weight of the heater. Optionally, the heater comprises at least one additive dispersed within the polymeric material. Optionally, the at least one additive comprises carbon black. Optionally, the heater comprises at least one additive in an amount between 5% and 9% by weight of the heater. Thus, the heater may comprise between 22 and 33 wt% of a polymeric material such as PEEK or LCP, between 62 and 69 wt% of one or a combination of graphite, graphite-derived materials, graphite-based materials, and hexagonal boron nitride, and between 5 and 9 wt% of one or a combination of additives such as carbon black. At least one power source may be configured to provide current to such a heater during use to resistively heat the heater. Advantageously, such a heater may be easier to manufacture than similar heaters configured for resistive heating typically used in existing heaters for aerosol-generating devices. Advantageously, the thermoplastic nature of the polymeric material may allow the composite polymeric material to be suitably malleable for precise and controlled shaping. At the same time, by controlling and adjusting the concentration and distribution of filler particles dispersed within the polymer matrix, it may be advantageously possible to control the conductivity, and thus the amount of heat generated by the heater resistance when a voltage is applied to the heater. Other parameters, such as the length and cross-sectional surface area of the heater, may also be adjusted to fine tune the resistive behavior of the heater. Advantageously, such a heater may be magnetically transparent and highly resistive enough to minimize eddy currents induced in the heater due to the alternating magnetic field generated by the inductor coil in use.

Optionally, the inductor coil is a helical inductor coil. Optionally, an inductor is wrapped around one or both of the chamber and the heater. Optionally, the inductor coil at least partially surrounds one or both of the chamber and the heater. This may advantageously allow a concentrated magnetic field in the chamber.

Optionally, the inductor coil is wound at least partially around the heater, for example around the heater. The inductor coil may or may not be in direct contact with the heater. A spacer member may be present between the inductor coil and the heater. The spacing member may at least partially surround the heater. The inductor coil may be wound at least partially around the spacer member, for example around the spacer member. The spacer member may be electrically insulating. The spacer member may be substantially magnetically transparent. Thus, the characteristics described with respect to the optional magnetic transparency of the heater may also apply to the spacer member.

As an alternative to a spiral inductor coil, the inductor coil may be a flat spiral inductor coil, which may also be referred to as a pancake inductor coil. The flat spiral inductor coil may spiral in a single plane, for example around a central point. Similar to the spiral inductor coil, the flat spiral inductor coil may be configured to generate an alternating magnetic field in the chamber when supplied with an alternating current. The flat spiral inductor coil may form or be positioned adjacent to and optionally in contact with a side wall or base of the chamber. The flat spiral inductor coil may spiral in a plane parallel to the base of the chamber, particularly if the flat spiral inductor coil is positioned adjacent to and optionally in contact with the base of the chamber.

The heater may be substantially flat or substantially planar. In this case, the heater may at least partially define the chamber in the sense that the heater defines at least one side wall or base or at least one side wall and base of the chamber. It may be particularly advantageous for the heater to be flat in the case that the inductor coil is a flat spiral inductor coil, and vice versa. In this case, the flat heater and flat spiral inductor coils may lie in substantially parallel planes.

The device may include a housing. The housing may define at least a portion of a chamber. The housing of the device may be elongate. The housing may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics or composites containing one or more of these materials, or thermoplastic materials suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK) and polyethylene. The device may be configured to be held in a single hand during use.

The at least one power source may be or include at least one battery. The or each battery may be rechargeable. The or each battery may be removable from the battery compartment. The or each cell may be a lithium-based cell, for example a lithium cobalt cell, a lithium iron phosphate cell, a lithium titanate cell or a lithium polymer cell, or a nickel metal hydride cell or a nickel cadmium cell. The at least one power source may be or include another form of charge storage device, such as a capacitor. The at least one power source may have sufficient capacity to allow continuous aerosol generation for a period of at least six minutes, which corresponds to the typical time taken to draw a conventional cigarette.

According to the present disclosure, an aerosol-generating system is provided. The aerosol-generating system may comprise an aerosol-generating device as described above, for example an aerosol-generating device according to the first aspect. The aerosol-generating system may comprise an aerosol-generating article, such as the aerosol-generating article mentioned above with reference to the first aspect.

Thus, according to a second aspect of the present disclosure there is provided an aerosol-generating system comprising an aerosol-generating device according to the first aspect and an aerosol-generating article as mentioned in the first aspect.

The system (e.g., device) may include an air inlet. The system (e.g., the article or mouthpiece of the device) may include an air outlet. The system (e.g., article) may include an airflow path. The air flow path may connect the air inlet and the air outlet. In use, the airflow through the airflow path may directly contact the aerosol-forming substrate. In use, an air flow through the air flow path may flow through or past the aerosol-forming substrate. In use, air may flow through the air inlet, and then through the article, and then through the air outlet, for example in response to suction on any mouthpiece of the article or system. After flowing through the air outlet, the air may flow into the user's mouth.

As discussed above, the device may include a device air inlet, a device airflow path, and a device air outlet. Similarly, the article may include an article air inlet, an article airflow path, and an article air outlet. The article airflow path may flow through or past the aerosol-forming substrate. In use, air may flow through the device air inlet, then through the device air flow path, then through the device air outlet, then through the product air inlet, then through the product air flow path, then through the product air outlet, and then into the user's mouth, for example in response to suction on any mouthpiece of the product or system.

The device air inlet may be located at an end of the chamber, for example at an end of the chamber opposite the base. The device airflow path may be at least partially defined between an outer surface of the article and an inner surface of the chamber. The device airflow path may extend from or to the base of the chamber toward the base of the chamber. The device air outlet may be located at or adjacent to the base of the chamber. The article air inlet may be located at an upstream end of the article. In use, the upstream end of the article may be positioned at or adjacent to the base of the chamber. The article airflow path may flow through the article from the upstream end to the downstream end. The article air outlet may be located at the downstream end of the article.

The article may comprise or may be a cartridge. The cartridge may hold an aerosol-forming substrate. The cartridge may hold the susceptor. The cartridge may include a cartridge housing. One or both of the aerosol-forming substrate and the susceptor may be located within the cartridge housing.

The cartridge may have a length, a width, and a thickness. The thickness may be less than 0.5 times or 0.2 times the length, width, or both. In this case, the cartridge may be referred to as a flat or planar cartridge. The cartridge may be of any suitable shape and size, such as substantially right cylindrical or rectangular parallelepiped. The cartridge may be any of the cartridges described in WO2015177043, the contents of which are incorporated herein.

The susceptor may have a susceptor length, a susceptor width, and a susceptor thickness. The susceptor thickness may be less than 0.5 times or 0.2 times the susceptor length, susceptor width, or both. In this case, the susceptor may be referred to as a flat or planar susceptor. The aerosol-forming substrate may have a substrate length, a substrate width, and a substrate thickness. The substrate thickness may be less than 0.5 times or 0.2 times the substrate length, the substrate width, or both. In this case, the aerosol-forming substrate may be referred to as a flat or planar aerosol-forming substrate.

The susceptor may form, be attached to, or be positioned adjacent to the inner face of the cartridge housing. The susceptor may be in contact with the aerosol-forming substrate. The susceptor may be located between the aerosol-forming substrate and the inner face. The largest or second largest surface of the susceptor may be in contact with or positioned adjacent to the largest or second largest surface of the aerosol-forming substrate. This may be particularly advantageous when one or both of the susceptor and the aerosol-forming substrate are flat or planar. Advantageously, this may maximize the heat transfer from the susceptor to the aerosol-forming substrate in use.

The article may appear to be substantially similar to a conventional cigarette. The article may be substantially cylindrical in shape, such as a right cylinder. The article may have a length of between 30mm and 120mm, such as between 40mm and 80mm, such as about 45 mm. The article may have a diameter of between 3.5 mm and 10mm, such as between 4 mm and 8.5 mm, such as between 4.5 mm and 7.5 mm.

The shape of the substrate may be substantially cylindrical, such as a right cylinder. The inner and outer portions of the aerosol-forming substrate have been referred to herein. The inner portion may be or comprise an aerosol-forming material in an axially central portion (e.g. an axially central cylindrical portion or an axially central right cylindrical portion) of the aerosol-forming substrate. The outer portion may be or comprise an aerosol-forming material in an axially outer portion of the aerosol-forming substrate. The shape of the outer portion may be cylindrical, for example right cylindrical. The outer portion may have an annular cross-section, such as a circular annular cross-section. There may be no aerosol-forming substrate between the inner portion and the outer portion. The inner portion and the outer portion may be in contact. The entire aerosol-forming material of the aerosol-forming substrate may be found in the inner and outer portions.

Optionally, the article comprises a front rod. Optionally, the article comprises an aerosol-forming substrate. Optionally, the article comprises a first hollow tube, such as a first hollow acetate tube. Optionally, the article comprises a second hollow tube, such as a second hollow acetate tube. Optionally, the second hollow tube comprises one or more ventilation holes. Optionally, the article comprises an oral filter segment filter. Optionally, the article comprises a wrapper, such as a paper wrapper. Optionally, one or more or all of the front rod, aerosol-forming substrate, first hollow tube, second hollow tube (if present), and mouth filter segment filter are defined by a wrapper.

Optionally, the front bar is disposed at the most upstream end of the article. Optionally, an aerosol-forming substrate is disposed downstream of the front rod. Optionally, the first hollow tube is arranged downstream of the aerosol-forming substrate. Optionally, a second hollow tube is arranged downstream of the first hollow tube. Optionally, the mouth filter segment filter is disposed downstream of one or both of the first hollow tube and the second hollow tube. Optionally, the mouth filter segment filter is disposed at the most downstream end of the article. Optionally, the downstream-most end of the article (which may be referred to as the mouth end of the article) may be configured for insertion into the mouth of a user. The user may be able to inhale, for example, directly on the mouth end of the article.

One or more of the front rod, aerosol-forming substrate, first hollow tube, second hollow tube, and mouth filter segment filter may be substantially cylindrical in shape, such as right cylindrical. One or more of the front rod, aerosol-forming substrate, first hollow tube, second hollow tube, and mouth filter segment filter may have a diameter of between 3.5mm and 10 millimeters. Optionally, the front bar has a length between 2mm and 10 mm. Optionally, the aerosol-forming substrate within the article has a length of between 5 and 20 millimeters. Optionally, the first hollow tube has a length of between 2mm and 20 mm. Optionally, the second hollow tube has a length of between 2mm and 20 mm. Optionally, the mouth filter segment filter has a length of between 5mm and 20 mm.

In accordance with the present disclosure, a method of controlling an aerosol-generating device or an aerosol-generating system is provided. The aerosol-generating device may be an aerosol-generating device as described above, for example an aerosol-generating device according to the first aspect. The aerosol-generating system may be an aerosol-generating system as described above, for example an aerosol-generating system according to the second aspect.

Thus, according to a third aspect of the present disclosure, there is provided a method of controlling an aerosol-generating device according to the first aspect or an aerosol-generating system according to the second aspect.

Features described with respect to one aspect may be applicable to another aspect. For example, features described in relation to the apparatus of the first aspect may be applicable to one or both of the system of the second aspect and the method of the third aspect, features described in relation to the system of the second aspect may be applicable to one or both of the apparatus of the first aspect and the method of the third aspect, and features described in relation to the method of the third aspect may be applicable to one or both of the apparatus of the first aspect and the system of the second aspect.

In particular, as will be appreciated by the skilled person after reading the present disclosure, the features described in relation to the controller configurable to be described in relation to the first aspect are applicable to the method of the third aspect. The method may comprise any steps to be done by the controller configuration of the apparatus of the first aspect.

Optionally, the apparatus comprises at least one power source and the method comprises independently controlling the supply of power from the at least one power source to the heater and the supply of power from the at least one power source to the inductor coil. Optionally, the apparatus comprises a first power source and a second power source different from the first power source, and the method comprises independently controlling the supply of power from the first power source to the heater and the supply of power from the second power source to the inductor coil. Advantageously, independently controlling the power supply to the inductor coil and the heater may allow for independent control of their temperature.

Optionally, the method comprises controlling the supply of electrical power from the at least one power source to one or both of the inductor coil and the heater during the maintenance phase to maintain the temperature of the heating zone within a heating zone maintenance temperature range. All optional features discussed above with respect to the heating zone maintenance temperature range apply. Optionally, the method comprises not supplying power from at least one power source to the inductor coil during the maintenance phase.

Optionally, the method includes one or both of ending the maintenance phase and starting the aspiration phase when the device (e.g., an aspiration detection mechanism of the device) detects aspiration or the start of aspiration. Optionally, the method includes adjusting (e.g., increasing) one or both of the power supply to the heater and the power supply to the inductor coil when the device (e.g., a suction detection mechanism of the device) detects suction or the start of suction. Advantageously, this may allow the device to respond quickly to user suction and generate an aerosol accordingly.

Optionally, the method comprises controlling the supply of electrical power from the at least one power source to one or both of the inductor coil and the heater during the pumping phase to maintain the temperature of the heating zone within the heating zone pumping temperature range. All optional features discussed above with respect to the heating zone suction temperature range apply.

Optionally, the method includes adjusting (e.g., reducing) one or both of the power supply to the heater and the power supply to the inductor coil when the device (e.g., a suction detection mechanism of the device) detects the end of suction. Optionally, the method includes performing one or both of an end suction phase and a start maintenance phase when the device (e.g., a suction detection mechanism of the device) detects the end of suction. Advantageously, this may allow the device to quickly respond to the end of a user's inhalation and accordingly cease generating aerosols. Reverting to the maintenance phase may advantageously allow the device to keep the aerosol-forming substrate warm so as to reduce the time required to generate aerosol in response to detecting the start of the next inhalation.

Optionally, the method comprises adjusting the supply of power from the at least one power source to the inductor coil in response to the device (e.g. a suction detection mechanism of the device) detecting suction, for example to increase the temperature of the susceptor.

Optionally, the method includes adjusting the supply of power from the at least one power source to the heater in response to the device (e.g., a suction detection mechanism of the device) detecting suction. Optionally, the method includes controlling the supply of power from the at least one power source to the heater in the same manner as during the maintenance phase in response to the device (e.g., a suction detection mechanism of the device) detecting suction.

Reference herein to an electrical power supply may refer to an electrical power supply, such as a current supply at a potential difference or voltage. Reference herein to controlling the supply of electrical power may refer to controlling one or both of the current and voltage of the electrical power. For example, controlling the power supply may include controlling one or more of a current magnitude, a current frequency, and a voltage magnitude of the power.

As used herein, the term "aerosol-generating article" or simply "article" may refer to an article capable of generating or releasing an aerosol (e.g., when heated).

As used herein, the term "aerosol-forming substrate" may refer to a substrate capable of releasing an aerosol or volatile compounds that may form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may comprise one or more aerosol-forming agents or aerosol-forming materials. The aerosol-forming substrate may be adsorbed, coated, impregnated or otherwise loaded onto a carrier or support. The aerosol-forming substrate may conveniently be an aerosol-generating article or a part of a smoking article.

Optionally, the aerosol-forming substrate is a solid aerosol-forming substrate. However, the aerosol-forming substrate may comprise both a solid component and a liquid component. Alternatively, the aerosol-forming substrate may be a liquid aerosol-forming substrate.

Optionally, the aerosol-forming substrate comprises nicotine. Optionally, the aerosol-forming substrate comprises tobacco. Alternatively or additionally, the aerosol-forming substrate may comprise tobacco-free aerosol-forming material.

As used herein, the term "aerosol-former" may refer to any suitable known compound or mixture of compounds that facilitates aerosol formation when in use and that is substantially resistant to thermal degradation at the operating temperature of the aerosol-generating article. Suitable aerosol formers are known in the art and include, but are not limited to, polyols such as propylene glycol, triethylene glycol, 1, 3-butanediol, and glycerol, esters of polyols such as mono-, di-, or triacetin, and aliphatic esters of mono-, di-, or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers are polyols or mixtures thereof such as propylene glycol, triethylene glycol, 1, 3-butanediol and most preferably glycerol. The aerosol-forming substrate may comprise one or more aerosol-forming agents.

As used herein, the "aerosolization temperature" of an aerosol-forming substrate may refer to the temperature at which the aerosol-forming substrate releases an aerosol or volatile compounds that can form an aerosol or the lowest temperature at which the aerosol-forming substrate releases a substantial amount of aerosol or volatile compounds that can form an aerosol.

As used herein, the term "use process" may refer to a period of time during which a user applies a series of puffs to extract an aerosol from an aerosol-forming substrate.

As used herein, the term "aerosol-generating device" may refer to a device for use with an aerosol-generating article to enable the generation or release of an aerosol.

As used herein, the term "susceptor" may refer to an element comprising a material capable of converting magnetic field energy into heat. The susceptor may be heated when the susceptor is in an alternating magnetic field. Heating of the susceptor may be a result of at least one of hysteresis losses and eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

As used herein in reference to an aerosol-generating article, the terms "upstream" and "downstream" may be used to describe the relative position of a component or portion of a component of the aerosol-generating article with respect to the direction of air flow through the aerosol-generating article during use of the aerosol-generating article. The aerosol-generating article may comprise an upstream end through which, in use, air enters the article. The aerosol-generating article may comprise a downstream end through which, in use, air or aerosol exits the article.

Ranges, such as temperature ranges, have been mentioned herein. For the avoidance of doubt, any range mentioned herein may have only an upper limit, only a lower limit, or both an upper and lower limit unless otherwise indicated. The limits of the temperature range may be predetermined, such as any upper or lower limit of any one or more of the temperature ranges of the heating zone, heater or susceptor as discussed above. The limit value may be stored in the controller or in a memory, for example in the memory of the controller. The limit value may be stored as a temperature value or in another form indicative of a temperature value, for example as a value of the resistance of the component to which the temperature range applies. In this case, the resistance of the component may be monitored instead of the temperature of the component, and the resistance of the component may be compared to the temperature versus resistance data set to estimate the temperature of the component.

As used herein, the term "electrically insulating" may refer to a material having an electrical conductivity of less than 0.8x10 ⁴ siemens/meter in at least one direction (e.g., in all directions) at room temperature (20 degrees celsius) and 50% relative humidity.

As used herein, the term "electrical resistance" may refer to a material having an electrical conductivity of at least 0.8x10 ⁶ siemens/meter in at least one direction (e.g., in all directions) at room temperature (20 degrees celsius) and 50% relative humidity.

As used herein, the term "thermally conductive" may refer to a material having a thermal conductivity of at least 5, 10, 20, 50, or 100 watts/meter · kelvin in at least one direction (e.g., in all directions) at room temperature (20 degrees celsius) and 50% relative humidity.

The invention is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

Ex1. An aerosol-generating device, the aerosol-generating device comprising:

a chamber for receiving at least a portion of an aerosol-generating article comprising an aerosol-forming substrate;

A heater at least partially surrounding or defining the chamber and configured to provide a heating zone in the chamber, and

An inductor coil configured to generate an alternating magnetic field in the chamber when the inductor coil is supplied with an alternating current.

Ex2 the aerosol-generating device according to example Ex1, wherein the device comprises at least one power source and a controller.

Ex3 the aerosol-generating device of example Ex2, wherein the controller is configured to independently control the supply of power from the at least one power source to the heater and the supply of power from the at least one power source to the inductor coil.

Ex4 an aerosol-generating device according to any preceding example, wherein the device comprises a first power source and a second power source different from the first power source.

Ex5 the aerosol-generating device according to example Ex2 when dependent on example Ex3, wherein the controller is configured to independently control the supply of power from the first power source to the heater and the supply of power from the second power source to the inductor coil.

Ex6 the aerosol-generating device of example Ex2 or any preceding example when dependent on example Ex2, wherein during the maintenance phase the controller is configured to control the supply of power from the at least one power source to one or both of the inductor coil and the heater to maintain the temperature of the heating region within a heating region maintenance temperature range.

Ex7. An aerosol-generating device according to example Ex6, wherein the heating zone maintenance temperature range has an upper limit that is less than the aerosol-forming temperature required for the aerosol-forming substrate to form an aerosol.

Ex8 an aerosol-generating device according to example Ex6 or Ex7, wherein the heating zone maintenance temperature range has an upper limit of no more than 250, 200, or 170 degrees celsius.

Ex9 the aerosol-generating device according to any of examples Ex6 to Ex8, wherein the heating zone maintenance temperature range has a lower limit of at least 50, 100 or 140 degrees celsius.

Ex10 the aerosol-generating device according to any one of examples Ex6 to Ex9, wherein the heating zone maintains a temperature range between 50 to 250, 50 to 200, 50 to 170, 100 to 250, 100 to 200, 100 to 170, 140 to 250, 140 to 200, 140 to 170 degrees celsius.

Ex11 the aerosol-generating device according to example Ex2 or any preceding example when dependent on example Ex2, wherein during the maintenance phase the controller is configured to control the supply of electrical power from the at least one electrical power source to the heater to maintain the temperature of the heater within a heater maintenance temperature range.

Ex12. The aerosol-generating device according to example Ex11, wherein the heater maintenance temperature range has an upper limit that is less than a temperature required by the heater to sufficiently heat the aerosol-forming substrate to form an aerosol.

Ex13 an aerosol-generating device according to example Ex11 or Ex12, wherein the heater maintenance temperature range has an upper limit of no more than 250, 200, or 170 degrees celsius.

Ex14 an aerosol-generating device according to example Ex11, ex12 or Ex13, wherein the heater maintenance temperature range has a lower limit of at least 50, 100 or 140 degrees celsius.

Ex15 an aerosol-generating device according to any preceding example, wherein the aerosol-generating article comprises a susceptor.

Ex16 an aerosol-generating device according to any of examples Ex1 to Ex15, wherein the device comprises a susceptor.

Ex17 an aerosol-generating device according to example Ex15 or Ex16, wherein the susceptor is a pin, vane or strip protruding into the chamber.

Ex18. The aerosol-generating device according to example Ex15 or Ex16 or Ex17, when dependent on example Ex2, wherein during the maintenance phase the controller is configured not to supply power from the at least one power source to the inductor coil.

Ex19 the aerosol-generating device according to example Ex15 or Ex16 or Ex17, when dependent on example Ex2, wherein during a maintenance phase the controller is configured to control the supply of electrical power from the at least one electrical power source to the inductor coil to maintain the temperature of the susceptor in the chamber within a susceptor maintenance temperature range.

Ex20. An aerosol-generating device according to example Ex19, wherein the susceptor maintenance temperature range has an upper limit less than a temperature required by the susceptor to sufficiently heat the aerosol-forming substrate to form an aerosol.

Ex21 an aerosol-generating device according to example Ex19 or Ex20, wherein the susceptor maintenance temperature range has an upper limit of no more than 250, 200, or 170 degrees celsius.

Ex22 an aerosol-generating device according to example Ex19, ex20 or Ex21, wherein the susceptor maintenance temperature range has a lower limit of at least 50, 100 or 140 degrees celsius.

Ex23 an aerosol-generating device according to any preceding example, wherein the device comprises a flow restrictor, such as a venturi tube.

Ex24 an aerosol-generating device according to any preceding example, wherein the device comprises a suction detection mechanism.

Ex25 the aerosol-generating device according to example Ex24, wherein the suction detection mechanism comprises a pressure sensor.

Ex26. The aerosol-generating device of example Ex25 when dependent on example Ex23, wherein the pressure sensor is configured to sense a pressure of the airflow through the flow restrictor.

Ex27. The aerosol-generating device according to example Ex24 or Ex25 or Ex26, when dependent on example Ex2, wherein the controller is configured to perform one or both of an end maintenance phase and a start of a suction phase when the suction detection mechanism detects suction or the start of suction.

Ex28. According to the aerosol-generating device of example Ex24 or Ex25 or Ex26 or Ex27, when dependent on example Ex2, wherein the controller is configured to perform one or both of a start-up maintenance phase and an end-of-draw phase when the end of draw is detected by the draw detection mechanism.

Ex29 an aerosol-generating device according to example Ex2 or any preceding example when dependent on example Ex2, wherein the controller is configured to adjust, e.g. increase, one or both of the supply of power to the heater and the supply of power to the inductor coil based on the device detecting, determining or estimating any one or more of:

The suction is started;

the duration of the suction up to date reaching (e.g. increasing above) the first threshold;

The volume of suction up to date reaching (e.g. increasing above) the first threshold;

an instantaneous flow rate of the airflow generated by the suction that reaches (e.g., increases above) a first threshold;

Maintaining an instantaneous flow rate of the air flow generated by the suction above a first threshold for at least a first period of time;

a transient rate of change of the flow rate of the airflow generated by the suction reaching (e.g., increasing above) a first threshold;

maintaining a transient rate of change of the flow rate of the airflow generated by the suction above a first threshold for at least a first period of time;

Lowering the temperature of the heating zone or the heater below a lower threshold, and

The temperature of the heating zone or the heater is maintained below a lower threshold for at least a first period of time.

Ex30 an aerosol-generating device according to example Ex2 or any preceding example when dependent on example Ex2, wherein the controller may be configured to adjust (e.g. reduce) one or both of the supply of power to the heater and the supply of power to the inductor coil based on the device detecting, determining or estimating any one or more of:

Ending suction;

The duration of the suction up to date reaching (e.g. increasing above) the second threshold;

the volume of suction up to date reaching (e.g. increasing above) the second threshold;

an instantaneous flow rate of the air flow generated by the suction reaching (e.g., decreasing below) a second threshold;

maintaining an instantaneous flow rate of the air stream resulting from the suction below a second threshold for at least a second period of time;

a transient rate of change of the flow rate of the airflow generated by the suction reaching (e.g., decreasing below) a second (optionally negative) threshold;

Maintaining a transient rate of change of the flow rate of the air stream resulting from the suction below a second (optionally negative) threshold for at least a second period of time;

increasing the temperature of the heating zone or the heater above an upper threshold, and

Maintaining the temperature of the heating zone or the heater above an upper threshold for a period of time.

Ex31 the aerosol-generating device according to example Ex2 or any preceding example when dependent on example Ex2, wherein in response to the device detecting draw, the controller is configured to increase the supply of power from the at least one power source to one or both of the inductor coil and the heater.

Ex32 an aerosol-generating device according to example Ex2 or any preceding example when dependent on example Ex2, wherein in response to the device detecting draw, the controller is configured to adjust, e.g. increase, the supply of power from the at least one power source to one or both of the inductor coil and the heater to increase the temperature of the heating zone, e.g. to increase to within a heating zone draw temperature range.

Ex33. An aerosol-generating device according to example Ex32, wherein the lower limit of the heating zone extraction temperature range is a sufficiently high temperature for the aerosol-forming substrate to form an aerosol.

Ex34 an aerosol-generating device according to example Ex32 or Ex33, wherein the heating zone extraction temperature range has a lower limit of at least 200, 250 or 300 degrees celsius.

Ex35 an aerosol-generating device according to example Ex32 or Ex33 or Ex34, wherein the heating zone suction temperature range has a lower limit of no more than 800, 650 or 500 degrees celsius.

An aerosol-generating device according to any preceding example, wherein the heater is configured to contact the aerosol-generating article when the aerosol-generating article is at least partially received in the chamber.

Ex37 an aerosol-generating device according to any preceding example, wherein the heater is substantially tubular.

Ex38 an aerosol-generating device according to any preceding example, wherein the heater is a resistive heater.

Ex39 an aerosol-generating device according to any preceding example, wherein the heater is substantially transparent to an alternating magnetic field generated by the inductor coil when the inductor coil is supplied with an alternating current.

Ex40 an aerosol-generating device according to any preceding example, wherein the heater comprises or consists of, for example, at least 90% by weight of a material that is one or more of substantially non-ferromagnetic, substantially paramagnetic, and substantially diamagnetic.

Ex41 an aerosol-generating device according to any preceding example, wherein the heater comprises or consists of, for example, at least 90 wt% of a material having one or more of a maximum relative magnetic permeability of no more than 2, 1.5 or 1.1, and a maximum relative magnetic permeability of at least 0.99, 0.999 or 1.

Ex42. An aerosol-generating device according to any preceding example, such as example Ex40 or Ex41, wherein the heater comprises or consists of, for example, at least 90 wt% of a material having a conductivity of less than 0.8 x 10 ⁴ or 0.8 x 10 ³ or 0.8 x 10 ² siemens/meter in at least one direction, for example in all directions, at 20 degrees celsius and 50% relative humidity.

Ex43 an aerosol-generating device according to any preceding example, wherein the heater comprises a ceramic material.

Ex44 an aerosol-generating device according to any preceding example, wherein the heater comprises a polymer composite.

Ex45 an aerosol-generating device according to example Ex44, wherein the polymer composite comprises a polymeric material, such as at least one polymeric material selected from the list consisting of Polyetheretherketone (PEEK) and Liquid Crystal Polymer (LCP).

Ex46 the aerosol-generating device according to any of examples Ex44 to Ex45, wherein the polymer composite comprises at least one of graphite, a graphite-derived material, a graphite-based material, and hexagonal boron nitride.

Ex47. An aerosol-generating device according to example Ex44, wherein the polymer composite comprises a polymer material, such as at least one polymer material selected from the list consisting of Polyetheretherketone (PEEK) and Liquid Crystal Polymer (LCP), and at least one of graphite, graphite-derived materials (such as expanded graphite or graphite nano-platelets), and hexagonal boron nitride dispersed within the polymer material.

Ex48 the aerosol-generating device according to example Ex45 or Ex47, wherein the heater comprises the polymeric material in an amount between 22% and 33% by weight of the heater.

Ex49 the aerosol-generating device according to example Ex46 or Ex47, wherein the heater comprises at least one of graphite, graphite-derived material, and hexagonal boron nitride in an amount between 62% and 69% by weight of the heater.

An aerosol-generating device according to any of examples Ex45 or Ex47 or Ex48 or example Ex49 when dependent on example Ex47, wherein the heater comprises at least one additive dispersed within the polymeric material.

Ex51. The aerosol-generating device according to example Ex50, wherein the at least one additive comprises carbon black.

Ex52. The aerosol-generating device according to example Ex50 or Ex51, wherein the heater comprises the at least one additive in an amount between 5% and 9% by weight of the heater.

Ex53 an aerosol-generating device according to any preceding example, wherein the inductor coil at least partially surrounds the chamber.

Ex54 an aerosol-generating device according to any preceding example, wherein the inductor coil at least partially surrounds the heater.

Ex55 an aerosol-generating device according to any preceding example, wherein the inductor coil is a helical inductor coil.

Ex56 an aerosol-generating device according to any preceding example, wherein the chamber comprises an open first end through which at least a portion of the aerosol-generating article may optionally be inserted into the chamber.

Ex57 an aerosol-generating device according to any preceding example, wherein the chamber comprises an at least partially closed second end.

Ex58 the aerosol-generating device according to example Ex56, wherein the chamber comprises an at least partially closed second end opposite the open first end.

Ex59 an aerosol-generating system comprising an aerosol-generating device according to any preceding example, and an aerosol-generating article.

Ex60. A method of controlling an aerosol-generating device according to any preceding device example, wherein the device comprises at least one power source, and the method comprises independently controlling the supply of power from the at least one power source to the heater and the supply of power from the at least one power source to the inductor coil.

An Ex61. A method according to any preceding method example, wherein the apparatus comprises a first power source and a second power source different from the first power source, and the method comprises independently controlling the supply of power from the first power source to the heater and the supply of power from the second power source to the inductor coil.

An Ex62. A method according to any preceding method example, wherein the method comprises controlling the supply of power from the at least one power source to one or both of the inductor coil and the heater during a maintenance phase to maintain the temperature of the heating zone within a heating zone maintenance temperature range.

Ex63. A method according to any preceding method example, wherein the method comprises controlling the supply of power from the at least one power source to one or both of the inductor coil and the heater to increase the temperature of the heating zone, optionally to within a heating zone pumping temperature range, in response to detecting pumping.

Ex64. A method according to any preceding method example, wherein the method comprises adjusting the supply of power from the at least one power source to the inductor coil in response to detecting suction, for example to increase the temperature of the susceptor.

An Ex65. A method according to any preceding method example, wherein the method comprises not adjusting the supply of power from the at least one power source to the heater in response to detecting suction.

An Ex66. A method according to any preceding method example, wherein the method comprises controlling the supply of power from the at least one power source to the heater in the same manner as during a maintenance phase in response to detecting suction.

Examples will now be further described with reference to the accompanying drawings, in which:

figure 1 shows a first aerosol-generating system, and

Fig. 2 shows a second aerosol-generating system.

Fig. 1 shows a first aerosol-generating system 100. The system 100 comprises a first aerosol-generating device 10 and a first aerosol-generating article 172.

The apparatus 10 includes a housing 12 and a right cylindrical chamber 16 for receiving a portion of a right cylindrical article 172. The chamber 16 includes an open end 18 through which the article 172 may be inserted into the chamber 16, and a largely closed end 20, also referred to as a base 20, opposite the open end 18. The diameter of the chamber 16 is slightly larger than the diameter of the article 172 to allow the article 172 to be inserted into the chamber 16.

The apparatus 10 includes a heater 50. The heater 50 is substantially tubular in shape and extends from the base 20 of the chamber 16 to the open end 18 of the chamber 16 to define the chamber 16. The heater 50 is a resistive heater formed from a polymer composite. Specifically, the heater 50 comprises a polymeric material and at least one of graphite, graphite-derived material, and hexagonal boron nitride dispersed within the polymeric material. The polymeric material is Polyetheretherketone (PEEK) but may alternatively be a Liquid Crystal Polymer (LCP). The heater 50 comprises a polymeric material in an amount of 27% by weight of the heater 50, although the number of such amounts may be between 22% and 33%. The graphite derived material comprises at least one of expanded graphite and graphite nanoplates. The heater 50 comprises at least one of graphite, graphite-derived material, and hexagonal boron nitride in an amount of 65% by weight of the heater 50, although the number of such amounts may be between 62% and 69%. The heater 50 also includes an additive (carbon black) dispersed within the polymeric material. The heater 50 contains the additive in an amount of 7% by weight of the heater 50, but the number of such amounts may be between 5% and 9%. The heater 50 is not inductively heatable. The heater 50 is substantially transparent to the alternating magnetic field generated by the inductor coil 24 in use. Thus, the heater 50 has no interaction or negligible interaction in use with the alternating magnetic field generated by the inductor coil 24 and thus with the heating of the susceptor element 164 described later.

The apparatus 10 includes a helical inductor coil 24 that includes a plurality of windings 26 that surround a heater 50.

The device 10 comprises a susceptor element 164 in a radially central position in the chamber 16, said susceptor element protruding from the base 20 of the chamber 16 towards the open end 18 of the chamber 16. As shown in fig. 1, the susceptor element 164 is shaped like a vane so as to penetrate the article 172 when the article 172 is received in the chamber 16. The susceptor element 164 is configured to be inductively heated by the inductor coil 24.

The device 10 includes a device air inlet 60 in one side of the housing 12, a device air outlet 62 in the base 20 of the chamber 16, and a device airflow path connecting the device air inlet 60 and the device air outlet 62. A flow restrictor 64 in the form of a venturi is located in the device airflow path. The device 10 includes a suction detection mechanism that includes a pressure sensor 66. The pressure sensor 66 is arranged to sense the pressure of the air flow in the flow restrictor 64.

The apparatus 10 includes a controller 40 and a power source 42 connected to the controller 40. The controller 40 is connected to the suction detection mechanism. Both the controller 40 and the power source 42 are connected to the inductor coil 24 and the heater 50. The controller 40 is configured to control the supply of electrical power from the power source 42 to the inductor coil 24. Specifically, the controller 40 is configured to provide high frequency alternating current from the power source 42 to the inductor coil 24 to generate an alternating magnetic field within the chamber 16. The controller 40 is also configured to control the supply of electrical power from the power source 42 to the heater 50. Specifically, the controller 40 is configured to provide a direct current from the power source 42 to the heater 50 to resistively heat the heater 50.

The article 172 includes the aerosol-forming substrate 104 in the form of a tobacco rod, the first hollow acetate tube 106, the second hollow acetate tube 108, the mouthpiece 110, and the outer wrapper 112. The article 172 is substantially right cylindrical in shape and has a length and diameter similar to a conventional cigarette.

The use of the system 100 will now be described. During use, a portion of the article 172 is inserted into the chamber 16 such that the susceptor element 164 penetrates the aerosol-forming substrate 104. This position is shown in fig. 1. The user then presses a button (not shown) to activate the device 10. In response, the controller 40 supplies power from the power source 42 to the heater 50 in the form of direct current until the heater 50 reaches a temperature of about 150 degrees celsius. In this embodiment, the temperature of the heater 50 is determined by the controller 40 by using the current and voltage supplied to the heater 50 to determine the resistance of the heater 50 and then comparing the resistance to a look-up table stored in the memory of the device 100 showing how the resistance of the heater 50 varies with its temperature. However, in other embodiments, a temperature sensor for sensing the temperature of the heater 50 may be used. As explained later, once the temperature of the heater 50 reaches about 150 degrees celsius, the power supplied to the heater 50 is continuously adjusted to maintain the temperature of the heater 50 at about 150 degrees celsius until suction is detected.

The phase during which the heater 50 is maintained at about 150 degrees celsius (which is slightly below the aerosolization temperature required for the aerosol-forming substrate 104 to form an aerosol, which in this embodiment is about 170 degrees celsius), is referred to as the maintenance phase. During the maintenance phase, no power is supplied to the inductor coil 24. Once the heater 50 reaches 150 degrees celsius, an indicator (not shown), such as a light, speaker, or tactile feedback device, indicates to the user that the device 10 is ready for aspiration.

The user then draws or inhales on the mouthpiece 110 of the article 172. This causes the airflow to be drawn through the device air inlet 60, through the flow restrictor 64, through the device air outlet 66, then through the article 172, and then into the user's mouth. This airflow path is shown by the dashed line in fig. 1.

The flow restrictor 64 reduces the cross-sectional area of the device airflow path. Thus, as the air flows through the flow restrictor 64, the air flow accelerates and the pressure decreases. The pressure in the flow restrictor 64 is sensed by a suction detection mechanism pressure sensor 66 and relayed to the controller 40 continuously or at frequent intervals such as every 50 milliseconds. When the pressure in the flow restrictor decreases by a significant amount, thus indicating to the user that a puff is being drawn on the mouthpiece 110, the maintenance phase ends and the puff phase begins.

In response to detecting the pump, at the beginning of the pump phase, the controller 40 does not change the power supplied to the heater 50, but rather begins to provide alternating current from the power supply 42 to the inductor coil 24. This results in the generation of an alternating magnetic field in the chamber 16 which inductively heats the susceptor element 164 by inducing eddy currents and hysteresis losses in the susceptor element 164. The susceptor element 164 then heats the aerosol-forming substrate 104 to above the aerosolization temperature at which the aerosol-forming substrate 104 forms an aerosol.

In this embodiment, during the pumping phase, the controller 40 maintains the temperature of the heater 50 at approximately 150 degrees celsius in the same manner as explained with reference to the maintenance phase. During the pumping phase, the controller 40 controls the supply of power from the power source 42 to the inductor coil 24 to heat the susceptor element 164 such that the susceptor reaches approximately 400 degrees celsius and the average temperature in the heating zone reaches approximately 300 degrees celsius. One or more temperature sensors supply feedback to the controller 40 regarding the temperature of one or both of the heating zone and susceptor element 164 to allow the controller 40 to control the supply of power to the susceptor element 164 to one or both of maintain the temperature of the susceptor at about 400 degrees celsius and the average temperature in the heating zone at about 300 degrees celsius.

As the airflow passes through the aerosol-forming substrate 104 during the drawing phase, as shown by the dashed lines in fig. 1, aerosol generated by the heating of the aerosol-forming substrate 104 is entrained in the airflow. The aerosol then flows along the length of the article 172 and through the mouthpiece 110 to the user.

When the pressure sensor 66 senses that the pressure in the flow restrictor 64 has returned to atmospheric or near atmospheric, this may indicate that suction has ended. When the controller 40 determines that the suction has ended, the controller 40 ends the suction phase and returns to the maintenance phase. Accordingly, the controller 40 stops supplying power to the inductor coil 24 and maintains the power supply to the heater 50 to maintain the temperature of the heater at about 150 degrees celsius.

During the course of use, a similar suction phase is repeated for each of the multiple suction. After each suction phase, a maintenance phase exists. The indicator indicates to the user that the use process is over after several aspiration phases during the use process or after a period of time has elapsed after the first aspiration phase of the use process. This may coincide with the time that it is expected that most of the aerosol-forming substrate 104 has been heated sufficiently to form an aerosol, so the aerosol-forming substrate 104 is substantially depleted. Then, the controller 40 stops supplying power to the heater 50 and the inductor coil 24. The device 10 may then be turned off and await re-activation by the button for another use procedure.

Fig. 2 shows a second aerosol-generating system 200. The system 200 comprises a second aerosol-generating device 210 and a second aerosol-generating article 102. The second aerosol-generating system 200 is similar to the first aerosol-generating system 100 and so only differences are described herein. The same reference numerals are used to denote the same features.

The device 210 of fig. 2 does not comprise susceptor elements. In the system 200 of fig. 2, the article 102 includes the susceptor element 114. The susceptor element 114 is located at a radial central position in the aerosol-forming substrate 104 and extends along the entire length of the aerosol-forming substrate 104.

The device 210 of fig. 2 does not include a heater 50, but instead includes a different heater 52. The heater 52 is substantially tubular in shape and extends from the base 20 of the chamber 16 to the open end 18 of the chamber 16 to define the chamber 16. The heater 52 includes a substantially tubular electrically insulating substrate made of ceramic. The heater 52 includes resistive tracks on the inner surface of the electrically insulating substrate. The heater 52 includes a thin protective coating, such as a glass or ceramic coating, over the resistive track and optionally also over the inner surface of the electrically insulating substrate. The protective coating prevents direct contact between the article inserted into the chamber 16 and the resistive track. The heater 52 is not inductively heatable. The heater 52 is substantially transparent to the alternating magnetic field generated by the inductor coil 24 in use. The heater 52 is comprised of a substantially non-ferromagnetic material. The heater 52 has no interaction or negligible interaction in use with the alternating magnetic field generated by the inductor coil 24 and thus with the heating of the susceptor element 114 described later.

The device 210 of fig. 2 includes a first power source 44 and a second power source 46 instead of the single power source 42 of the device 100 of fig. 1. The first power supply 44 is connected to the controller 40 and the heater 52. A second power supply 46 is connected to the controller 40 and the inductor coil 24. Similar to the device 10 of fig. 1, in the device 210 of fig. 2, the controller 40 is connected to a suction detection mechanism. The controller 40 is configured to control the supply of power from the first power source 44 to the heater 52. Specifically, the controller 40 is configured to provide a direct current from the first power source 44 to the resistive track of the heater 52 to resistively heat the track. The controller 40 is configured to control the supply of electrical power from the second power source 46 to the inductor coil 24. Specifically, the controller 40 is configured to provide high frequency alternating current from the second power source 46 to the inductor coil 24 to generate an alternating magnetic field within the chamber 16.

The use of the system 200 will now be described. During use, a portion of the article 102 is inserted into the chamber 16. This position is shown in fig. 2. The user then presses a button (not shown) to activate the device 210. In response, the controller 40 supplies power in the form of direct current from the first power source 44 to the heater 52, specifically the resistive track, until the heater 52 reaches a temperature of about 100 degrees celsius. In this embodiment, the temperature of the heater 52 is determined by the controller 40 by using a temperature sensor for sensing the temperature of the inner surface of the heater 52. As explained later, once the temperature of the heater 52 reaches 100 degrees celsius, the power supplied to the heater 50 is continuously adjusted to maintain the temperature of the heater 52 at about 100 degrees celsius until suction is detected.

In addition, the controller 40 supplies power from the second power source 46 to the inductor coil 24 to generate an alternating magnetic field in the chamber and inductively heat the susceptor element 114 to a temperature of about 100 degrees celsius, also in response to the user pressing a button. As will be explained later, once the temperature of the susceptor element 114 reaches about 100 degrees celsius, the power supplied to the inductor coil 24 is continuously adjusted to maintain the temperature of the susceptor element 114 at about 100 degrees celsius until aspiration is detected.

The phase during which the heater 52 and susceptor element 114 are maintained at about 100 degrees celsius, which is below the aerosolization temperature required for the aerosol-forming substrate 104 to form an aerosol, is referred to as a maintenance phase. In this embodiment, the aerosol-forming substrate 104 has an aerosolization temperature of about 170 degrees celsius. Once both the heater 52 and the susceptor element 114 have reached 100 degrees celsius, an indicator (not shown), such as a light, speaker, or tactile feedback device, indicates to the user that the device 10 is ready for aspiration.

The user then draws or inhales on the mouthpiece 110 of the article 102. This causes the airflow to be drawn through the device air inlet 60, through the flow restrictor 64, through the device air outlet 66, then through the article 102, and then into the user's mouth. This airflow path is shown by the dashed line in fig. 2.

In response to detecting the draw, the controller 40 increases the power supplied to the heater 52 and the inductor coil 24. Specifically, the controller 40 increases the magnitude of the direct current supplied to the heater 52 and the magnitude of the alternating current supplied to the inductor coil 24. This results in heating the heater 52 to a temperature of about 250 degrees celsius and heating the susceptor 114 to a temperature of about 250 degrees celsius. This heats the entire heating zone in the chamber 16 to about 250 degrees celsius and heats the aerosol-forming substrate 104 above the aerosol-forming substrate 104 aerosol-forming temperature.

In this embodiment, the controller 40 maintains the temperature of the heater 52 at about 250 degrees celsius during the pumping phase. However, during the pumping phase, the controller 40 may adjust the power supplied to the inductor coil 24 based on one or more inputs. For example, input from a suction detection mechanism including pressure sensor 66 may be used to continuously estimate the flow rate or rate of change of flow of the airflow through device 210 resulting from suction. In this embodiment, in response to an input from the suction detection mechanism (i.e., the flow rate of the air flow through the device 210 has increased above a threshold), the controller 40 increases the supply of power from the second power source 46 to the inductor coil 24 to heat the susceptor 114 to approximately 300 degrees celsius. As will be appreciated by the skilled artisan upon reading this disclosure, this is but one of many ways in which the power to the heater or inductor coil may be adjusted in this manner during the pumping phase of either of the systems 100, 200 of fig. 1 and 2.

As the airflow passes through the aerosol-forming substrate 104 during the drawing phase, as shown by the dashed lines in fig. 2, the aerosol generated by the heating of the aerosol-forming substrate 104 is entrained in the airflow. The aerosol then flows along the length of the article 102 and through the mouthpiece 110 to the user.

When the pressure sensor 66 senses that the pressure in the flow restrictor has returned to or near atmospheric pressure, this may indicate that suction has ended. When the controller 40 determines that the suction has ended, the controller 40 ends the suction phase and returns to the maintenance phase. Accordingly, the controller 40 adjusts the power supplied to the inductor coil 24 and the heater 52 so that the temperature of the susceptor 114 and the heater 52 reaches and is then maintained at approximately 100 degrees celsius.

During the course of use, a similar suction phase is repeated for each of the multiple suction. After each suction phase, a maintenance phase exists. The indicator indicates to the user that the use process is over after several aspiration phases during the use process or after a period of time has elapsed after the first aspiration phase of the use process. This may coincide with the time that it is expected that most of the aerosol-forming substrate 104 has been heated sufficiently to form an aerosol, so the aerosol-forming substrate 104 is substantially depleted. Then, the controller 40 stops supplying power to the heater 52 and the inductor coil 24. The device 210 may then shut down and wait to be restarted for another use process.

For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing quantities, amounts, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Moreover, all ranges include the disclosed maximum and minimum points, and include any intervening ranges therein that may or may not be specifically enumerated herein. Thus, in this context, the number a is understood to be 10% of a±a. In this context, the number a may be considered to include values within the general standard error of measurement of the property modified by the number a. In some cases, as used in the appended claims, the number a may deviate from the percentages recited above, provided that the amount of deviation a does not materially affect the basic and novel characteristics of the claimed invention. Moreover, all ranges include the disclosed maximum and minimum points, and include any intervening ranges therein that may or may not be specifically enumerated herein.

Claims

1. An aerosol generating apparatus, the aerosol generating apparatus comprising:

A chamber for receiving at least a portion of an aerosol-generated article comprising an aerosol-forming matrix;

A resistance heater that at least partially surrounds or defines the chamber and is configured to provide a heating zone within the chamber; and

An inductor coil, which at least partially surrounds the heater and is configured to generate an alternating magnetic field in the chamber when the inductor coil is supplied with an alternating current.

2. The aerosol generating apparatus according to claim 1, wherein the heater comprises a tubular electrically insulating substrate and a resistance track on the electrically insulating substrate.

3. The aerosol generating apparatus according to any of the preceding claims, wherein the heater comprises or is composed of a substantially non-ferromagnetic material.

4. The aerosol generating apparatus according to any of the preceding claims, wherein the heater comprises, or is composed of, a material having a maximum relative permeability of not more than 2 and an electrical conductivity of less than 0.8 × ^10⁴ Siemens/m in at least one direction at 20 degrees Celsius and 50% relative humidity.

5. The aerosol generating apparatus according to any of the preceding claims, wherein the heater is configured to contact the aerosol generating article when the aerosol generating article is at least partially received in the chamber.

6. The aerosol generating apparatus according to any of the preceding claims, wherein the heater comprises one or both of a ceramic material and a polymer composite material.

7. The aerosol generating apparatus according to any of the preceding claims, wherein the sensor coil is wound around the heater.

8. The aerosol generating apparatus according to any of the preceding claims, wherein the apparatus includes at least one power source and a controller, and wherein the controller is configured to independently control the power supply from the at least one power source to the heater and the power supply from the at least one power source to the inductor coil.

9. The aerosol generating apparatus of claim 8, wherein during the sustaining phase, the controller is configured to control the power supply from the at least one power source to one or both of the inductor coil and the heater to maintain the temperature of the heating zone within a sustaining temperature range for the heating zone.

10. The aerosol generating apparatus according to claim 9, wherein the heating zone maintains a temperature range with an upper limit of no more than 250 degrees Celsius.

11. The aerosol generating apparatus according to claim 9 or 10, wherein the heating zone maintains a temperature range with a lower limit of at least 50 degrees Celsius.

12. The aerosol generating apparatus according to any one of claims 9 to 11, wherein during the sustaining phase, the controller is configured to control the power supply from the at least one power source to the inductor coil, so as to:

Power is not supplied from the at least one power source to the inductor coil; or

The temperature of the receptors in the chamber is maintained within the receptor maintenance temperature range.

13. The aerosol generating apparatus according to any preceding claim, wherein the apparatus includes a suction detection mechanism configured to detect suction on the apparatus or on an article in the chamber, and in response to the suction detection mechanism detecting suction, the controller is configured to increase the power supply from the at least one power source to the sensor coil.

14. An aerosol generation system comprising an aerosol generation apparatus according to any of the preceding claims, and an aerosol generation article for receiving at least partially in a chamber of the apparatus.

15. A method for controlling an aerosol generating apparatus according to any of the preceding claims, the method comprising independently controlling the power supply from the at least one power source to an external heater and the power supply from the at least one power source to the inductor coil.