FIELD
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The present disclosure relates to an aerosol generating apparatus and a method of controlling an aerosol generating apparatus.
BACKGROUND
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A typical aerosol generating apparatus may comprise a power supply, an aerosol generating unit that is driven by the power supply, an aerosol precursor, which in use is aerosolised by the aerosol generating unit to generate an aerosol, and a delivery system for delivery of the aerosol to a user.
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Different aerosol generating technologies are utilised in aerosol generating apparatuses. Infrared heaters have been proposed but to date have not seen widespread use in aerosol generating apparatuses when compared to, say, induction heaters.
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Despite the effort already invested in the development of aerosol generating apparatuses/systems further improvements are desirable.
SUMMARY
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In a first aspect the present disclosure provides an aerosol generating apparatus that comprises a precursor chamber for receiving an aerosol precursor; an IR heating system configured to emit IR radiation. The IR heating system may be configured to emit IR radiation across a total range of wavenumbers.
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The aerosol generating apparatus may be operable by a user to initiate an aerosol session over which to generate aerosol from the aerosol precursor using the IR heating system.
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During the aerosol session, the IR heating system may be configured to increase, relative to the total radiant power output by the IR heating system, radiant power of IR radiation emitted across a target range of wavenumbers contained in the total range of wavenumbers.
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By increasing radiant power of IR radiation emitted across the target range relative to the total radiant power output by the IR heating system, the IR radiation emitted by the IR heating system may be adjusted over the aerosol session. The inventors observed that IR heating may result in an inconsistent aerosol session in which aerosol generated towards the beginning may significantly differ from aerosol generated towards the end of the aerosol session. By suitably adjusting the IR heating system over the aerosol session, i.e. "targeting" wavenumbers of the target range, consistency of the aerosol generated over the aerosol session may be improved.
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The target range may include 3600 to 2900 inverse-centimetres. By increasing over the aerosol session radiant power of IR radiation emitted across 3600 to 2900 inverse-centimetres, release of water vapour from the aerosol precursor may be increased. The inventors observed that, when using IR heating, the concentration of water vapour in the aerosol may decrease over the course of the aerosol session, such that a user of the aerosol generating apparatus may be left with a dry sensation. The inventors further observed that consistency of the concentration of water vapour may be improved by increasing radiant power in the specified target range of 3600 to 2900 inverse-centimetres over the aerosol session. Without wishing to be bound by theory, it is believed that absorption of IR radiation by water may be particularly high in the specified target range so that increasingly targeting this range of wavenumbers over the aerosol session may improve consistency of concentration of water vapour.
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It is known that the IR absorption spectrum of water involves many absorption peaks and, moreover, may depend on the substances included in the aerosol precursor. In light of the present disclosure, the skilled person will be able to identify ranges of wavenumbers for targeting release of water vapour from the aerosol precursor.
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In some examples, the IR heating system may be configured to increase, relative to the total radiant power output by the IR heating system, radiant power of IR radiation emitted across the target range of wavenumbers contained in the total range of wavenumbers to increase consistency of water vapour concentration in the aerosol generated by the IR heating system.
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The target range may include 1500 to 800 inverse-centimetres, optionally 1500 to 1050 inverse-centimetres. By increasing over the aerosol session radiant power of IR radiation emitted across the specified target range of wavenumbers, release of nicotine from the aerosol precursor may be increased. The inventors observed that, when using IR heating, the concentration of nicotine in the aerosol may decrease over the course of the aerosol session, such that a user of the aerosol generating apparatus may experience unexpectedly low amounts of nicotine towards the end of the aerosol session (and may experience unexpectedly high amounts of nicotine towards the beginning of the aerosol session). The inventors further observed that consistency of the concentration of nicotine may be improved by increasing radiant power in the specified target range of 1500 to 800 inverse-centimetres, and particularly 1500 to 1050 inverse-centimetres, over the aerosol session. Without wishing to be bound by theory, it is believed that absorption of IR radiation by vegetable glycerine in the aerosol precursor may be particularly high in the specified target range, and that targeting the vegetable glycerine may increase release of nicotine.
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It is known that the release of nicotine from the aerosol precursor may depend on the substances included in the aerosol precursor, such as vegetable glycerine. In light of the present disclosure, the skilled person will be able to identify ranges of wavenumbers for targeting release of nicotine from the aerosol precursor.
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In some examples, the IR heating system may be configured to increase, relative to the total radiant power output by the IR heating system, radiant power of IR radiation emitted across the target range of wavenumbers contained in the total range of wavenumbers to increase consistency of nicotine concentration in the aerosol generated by the IR heating system.
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The IR heating system may be configured to adjust total radiant power being output during the aerosol session. Total radiant power is understood to describe the total amount of radiative power that is being emitted by the IR heating system. As such, the radiant power of the IR radiation emitted across the target range is a portion of the total radiant power. In general, the IR heating system may increase, decrease or maintain the total radiant power over the aerosol sessions. Thus, total radiant power towards the beginning of the aerosol session may be lower, higher or about equal to total radiant power towards the end of the aerosol session.
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The IR heating system may be configured to decrease the total radiant power during the aerosol session. The inventors observed that decreasing the total radiant power during the aerosol session may improve the consistency of the aerosol being generated where wavenumbers are targeted for increasing water vapour; e.g. in the range of 3600 to 2900 inverse-centimetres. More particularly, by targeting release of water vapour, the sensory experience may be affected in that higher concentration of water vapour may be perceived as comparatively hotter. By reducing the total radiant power, for example simultaneously as increasing the radiant power across the target range, the perceived temperature increase may be reduced or entirely alleviated. This may further contribute to improving consistency of the aerosol generated over the aerosol session.
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In some examples, the IR heating system is configured to decrease the total radiant power at the same time as increasing the radiant power of IR radiation emitted across the target range.
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The IR heating system may be configured to maintain or increase the total radiant power during the aerosol session. The inventors observed that maintaining or increasing the total radiant power during the aerosol session may improve consistency of the aerosol being generated where wavenumbers are targeted for increasing release of nicotine; e.g. in the range of 1500 to 800 inverse-centimetres, optionally 1500 to 1050 inverse-centimetres. For example, following expiry of at least part of the aerosol session, an additional heating element may be powered to target the release of nicotine. Where this additional heating element is being powered without decreasing power to any other heating element(s), the total radiant power being output by the IR heating system increases upon powering the additional heating element.
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The IR heating system may be configured to emit IR radiation across the target range at a low radiant power towards the beginning of the aerosol session. For example, the IR heating system may be configured to emit the IR radiation across the target range at the low radiant power until expiry of at least 30% of the aerosol session; optionally until expiry of at least 40% the aerosol session.
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The low radiant power may be zero, or may be a low non-zero value such as a minimum which is the minimum of radiant power emitted over the course of the aerosol session.
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The IR heating system may be configured to emit IR radiation across the target range at a high radiant power towards the end of the aerosol session. For example, the IR heating system may be configured to emit the IR radiation across the target range at the high radiant power from expiry of at least 90% of the aerosol session; optionally from expiry of at least 70% of the aerosol session.
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The high radiant power may be a maximum of radiant power emitted over the course of the aerosol session. In some examples, high radiant power may correspond to the maximum rated radiant power deliverable by the corresponding heating element.
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The IR heating system may be configured to increase the IR radiation emitted across the target range from the low radiant power to the high radiant power during the aerosol session.
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The IR heating system may be configured to gradually increase the radiant power of the IR radiation across the range of wavenumbers during the aerosol session. Gradually increasing the radiant power may, in some examples, correspond to discretely increasing the radiant power a plurality of times.
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In some examples, the IR heating system may be configured to increase the radiant power of the target range over a period of at least 20 seconds, or at least 30 seconds.
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The IR heating system may be configured to initiate a preheat phase for preheating, e.g. with the aerosol precursor exposed to the IR heating system. Preheating is known in the art and may typically involve heating the heating system and/or aerosol precursor towards a desired temperature, prior to commencing of the aerosol session throughout which a user is intended to use the aerosol generating apparatus.
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The preheat phase may have a predetermined duration of at least 15 seconds, or of at least 20 seconds. The duration of the preheat phase may be no more than 40 seconds, or no more than 30 seconds. In some examples, the aerosol generating device is configured to initiate the aerosol session following expiry of the predetermined duration of the preheat phase.
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The IR heating system may be configured to, during the preheat phase, increase and subsequently decrease the radiant power of IR radiation emitted across the target range as compared to the total radiant power output by the IR heating system. For example, the IR heating system may be configured to decrease radiant power of IR radiation emitted across the target range upon expiry of 60% or less of the preheat phase.
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The inventors observed that preheating with IR heater technology may result in comparatively hot aerosol being stored inside the aerosol precursor. The stored aerosol temporarily remains at the comparatively high temperature and, if the user puffs during this time, may be released. This may result in a non-optimal experience for the user, for example with unexpectedly high temperature. By decreasing the radiant power emitted across the target range during the preheat phase, the aerosol may settle within the aerosol precursor, for example by heating the aerosol precursor, and provide for an improved sensory experience.
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The IR heating system may include a plurality of IR emitters configured to emit IR radiation. In some examples, the IR emitters may be provided as electrothermal elements.
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The plurality of IR emitters may include at least one first IR emitter configured to emit IR radiation having a first spectrum, or a first spectral power distribution, and a second IR emitter configured to emit IR radiation having a second spectrum, or a second spectral power distribution, different from the first spectrum.
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The first spectrum may peak in the target range, or the first spectral power distribution may peak in the target range, or the majority of the radiant power output by the at least one first IR emitter may be within the target range (e.g. more than 50%, or more than 75%). The IR heating system may be configured to increase radiant power emitted by the at least one first IR emitter to increase radiant power of IR radiation emitted across the target range.
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The at least one second IR emitter may be configured to emit IR radiation with comparatively little IR radiation across the target range; for example less than 50%, or less than 40%, of the IR radiation emitted by the second IR emitter have wavenumbers within the target range. For example, the second spectrum may be predominantly outside the target range (e.g. more than 50%, or more than 75%); for example the majority of the radiant power output by the second IR emitter may be outside the target range (e.g. more than 50%, or more than 75%).
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According to a second aspect, there is provided a method of controlling an aerosol generating apparatus, which may implement any one or more features disclosed herein.
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The method may comprise providing the aerosol generating apparatus, wherein the aerosol generating apparatus includes a precursor chamber for receiving an aerosol precursor and an IR heating system configured to emit IR radiation across a total range of wavenumbers; initiating an aerosol session to cause generating of aerosol from an aerosol precursor using the IR heating system; during the aerosol session increasing, relative to the total radiant power output by the IR heating system, radiant power of IR radiation emitted across a target range of wavenumbers contained in the total range of wavenumbers to increase consistency of the aerosol generated over the aerosol session.
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The present disclosure may provide electrical circuitry and/or a computer program configured to cause an aerosol generating apparatus to perform any method or method step disclosed herein. A computer readable medium comprising the computer program is also disclosed.
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The preceding summary is provided for purposes of summarizing some examples to provide a basic understanding of aspects of the subject matter described herein. Accordingly, the above-described features should not be construed to narrow the scope or spirit of the subject matter described herein in any way. Moreover, the above and/or proceeding examples may be combined in any suitable combination to provide further examples, except where such a combination is clearly impermissible or expressly avoided. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following text and the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
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Aspects, features and advantages of the present disclosure will become apparent from the following description of examples in reference to the appended drawings in which like numerals denote like elements.
- Fig. 1 is a block system diagram showing an example aerosol generating apparatus.
- Fig. 2 is a block system diagram showing an example implementation of the apparatus of Fig. 1, where the aerosol generating apparatus is configured to generate aerosol from a solid precursor.
- Fig. 3 is a schematic diagram showing an example implementation of the apparatus of Fig. 2.
- Fig. 4 is a schematic side view of a heating system of the apparatus of Fig. 3, engaged with a consumable.
- Fig. 5 is another schematic side view of the heating system of Fig. 3, without the consumable.
- Fig. 6 is a graph illustrating a first example of radiant power output by the heating system.
- Fig. 7 is a graph illustrating a second example of radiant power output by the heating system.
- Fig. 8 is a graph illustrating a third example of radiant power output by the heating system.
- Fig. 9 is a plot of experimental data showing the absorbance of the consumable for a range of IR wavenumbers.
- Fig. 10 illustrates a method of controlling the apparatus.
DETAILED DESCRIPTION OF EMBODIMENTS
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Before describing several examples implementing the present disclosure, it is to be understood that the present disclosure is not limited by specific construction details or process steps set forth in the following description and accompanying drawings. Rather, it will be apparent to those skilled in the art having the benefit of the present disclosure that the systems, apparatuses and/or methods described herein could be embodied differently and/or be practiced or carried out in various alternative ways.
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Unless otherwise defined herein, scientific and technical terms used in connection with the presently disclosed inventive concept(s) shall have the meanings that are commonly understood by those of ordinary skill in the art, and known techniques and procedures may be performed according to conventional methods well known in the art and as described in various general and more specific references that may be cited and discussed in the present specification.
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Any patents, published patent applications, and non-patent publications mentioned in the specification are hereby incorporated by reference in their entirety.
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All examples implementing the present disclosure can be made and executed without undue experimentation in light of the present disclosure. While particular examples have been described, it will be apparent to those of skill in the art that variations may be applied to the systems, apparatus, and/or methods and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit, and scope of the inventive concept(s). All such similar substitutions and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the inventive concept(s) as defined by the appended claims.
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The use of the term "a" or "an" in the claims and/or the specification may mean "one," as well as "one or more," "at least one," and "one or more than one." As such, the terms "a," "an," and "the," as well as all singular terms, include plural referents unless the context clearly indicates otherwise. Likewise, plural terms shall include the singular unless otherwise required by context.
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The use of the term "or" in the present disclosure (including the claims) is used to mean an inclusive "and/or" unless explicitly indicated to refer to alternatives only or unless the alternatives are mutually exclusive. For example, a condition "A or B" is satisfied by any of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
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As used in this specification and claim(s), the words "comprising, "having," "including," or "containing" (and any forms thereof, such as "comprise" and "comprises," "have" and "has," "includes" and "include," or "contains" and "contain," respectively) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.
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Unless otherwise explicitly stated as incompatible, or the physics or otherwise of the embodiments, examples, or claims prevent such a combination, the features of examples disclosed herein, and of the claims, may be integrated together in any suitable arrangement, especially ones where there is a beneficial effect in doing so. This is not limited to only any specified benefit, and instead may arise from an "ex post facto" benefit. This is to say that the combination of features is not limited by the described forms, particularly the form (e.g. numbering) of example(s), embodiment(s), or dependency of claim(s). Moreover, this also applies to the phrase "in one embodiment," "according to an embodiment," and the like, which are merely a stylistic form of wording and are not to be construed as limiting the following features to a separate embodiment to all other instances of the same or similar wording. This is to say, a reference to 'an,' 'one,' or 'some' embodiment(s) may be a reference to any one or more, and/or all embodiments, or combination(s) thereof, disclosed. Also, similarly, the reference to "the" embodiment may not be limited to the immediately preceding embodiment. Further, all references to one or more embodiments or examples are to be construed as non-limiting to the claims.
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The present disclosure may be better understood in view of the following explanations, wherein the terms used that are separated by "or" may be used interchangeably:
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As used herein, an "aerosol generating apparatus" (or "electronic(e)-cigarette") may be an apparatus configured to deliver an aerosol to a user for inhalation by the user. The apparatus may additionally/alternatively be referred to as a "smoking substitute apparatus", if it is intended to be used instead of a conventional combustible smoking article. As used herein a combustible "smoking article" may refer to a cigarette, cigar, pipe or other article, that produces smoke (an aerosol comprising solid particulates and gas) via heating above the thermal decomposition temperature (typically by combustion and/or pyrolysis).
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As used herein, an "aerosol generating component" may refer to a component that includes an aerosol precursor. The component may include an aerosol generating unit e.g. it may be arranged as a cartomizer. The component may include a mouthpiece. The component may include an information carrying medium.
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With solid material implementations of the precursor, e.g. tobacco or reconstituted tobacco formulation, the component may be referred to as a "stick" or "package" or "heat-not-burn consumable". In a heat-not-burn consumable, the mouthpiece may be implemented as a filter and the consumable may be arranged to carry the precursor. The consumable may be implemented as a dosage or pre-portioned amount of material, including a loose-leaf product.
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The aerosol generating component, e.g. stick, package or consumable, may be for releasable coupling to a device body to form the aerosol generating apparatus.
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The device body may comprise a power supply for powering the aerosol generating unit.
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An aerosol generated by the apparatus may comprise an aerosol with particle sizes of 0.2 - 7 microns, or less than 10 microns, or less than 7 microns. This particle size may be achieved by control of one or more of: heater temperature; cooling rate as the vapour condenses to an aerosol; flow properties including turbulence and velocity. The generation of aerosol by the aerosol generating apparatus may be controlled by an input device. The input device may be configured to be user-activated, and may for example include or take the form of an actuator (e.g. actuation button) and/or an airflow sensor.
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Each occurrence of the aerosol generating apparatus being caused to generate aerosol for a period of time (which may be variable) may be referred to as an "activation" of the aerosol generating apparatus. The aerosol generating apparatus may be arranged to allow an amount of aerosol delivered to a user to be varied per activation (as opposed to delivering a fixed dose of aerosol), e.g. by activating an aerosol generating unit of the apparatus for a variable amount of time, e.g. based on the strength/duration of a draw of a user through a flow path of the apparatus (to replicate an effect of smoking a conventional combustible smoking article).
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The aerosol generating apparatus may be portable. As used herein, the term "portable" may refer to the apparatus being for use when held by a user.
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An example aerosol generating system may be a system for managing an aerosol generating apparatus. Such a system may include, for example, a mobile device, a network server, as well as the aerosol generating apparatus.
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As used herein, an "aerosol" may include a suspension of precursor, including as one or more of: solid particles; liquid droplets; gas. Said suspension may be in a gas including air. An aerosol herein may generally refer to/include a vapour. An aerosol may include one or more components of the precursor.
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As used herein, a "precursor" may include one or more of a: liquid; solid; gel; loose leaf material; other substance. The precursor may be processed by an aerosol generating unit of an aerosol generating apparatus to generate an aerosol. The precursor may include one or more of: an active component; a carrier; a flavouring. The active component may include one or more of nicotine; caffeine; a cannabidiol oil; a non-pharmaceutical formulation, e.g. a formulation which is not for treatment of a disease or physiological malfunction of the human body. The active component may be carried by the carrier, which may be a liquid, including propylene glycol and/or glycerine. The term "flavouring" may refer to a component that provides a taste and/or a smell to the user. The flavouring may include one or more of: Ethylvanillin (vanilla); menthol, Isoamyl acetate (banana oil); or other. The precursor may include a substrate, e.g. reconstituted tobacco to carry one or more of the active component; a carrier; a flavouring.
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As used herein, a "flow path" may refer to a path or enclosed passageway through an aerosol generating apparatus, e.g. for delivery of an aerosol to a user. The flow path may be arranged to receive aerosol from an aerosol generating unit. When referring to the flow path, upstream and downstream may be defined in respect of a direction of flow in the flow path, e.g. with an outlet being downstream of an inlet.
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As used herein, a "delivery system" may be a system operative to deliver an aerosol to a user. The delivery system may include a mouthpiece and a flow path. The delivery system may be at least partly within the aerosol generating component.
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As used herein, a "flow" may refer to a flow in a flow path. A flow may include aerosol generated from the precursor. The flow may include air, which may be induced into the flow path via a puff by a user.
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As used herein, a "puff" (or "inhale" or "draw") by a user may refer to expansion of lungs and/or oral cavity of a user to create a pressure reduction that induces flow through the flow path.
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As used herein, an "aerosol generating unit" may refer to a device configured to generate an aerosol from a precursor. The aerosol generating unit may include a unit to generate a vapour directly from the precursor (e.g. a heating system or other system) or an aerosol directly from the precursor (e.g. an atomiser including an ultrasonic system, a flow expansion system operative to carry droplets of the precursor in the flow without using electrical energy or other system). A plurality of aerosol generating units to generate a plurality of aerosols (for example, from a plurality of different aerosol precursors) may be present in an aerosol generating apparatus.
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As used herein, a "heating system" may refer to an arrangement of at least one heating element, which is operable to aerosolise a precursor once heated. The at least one heating element may be electrically resistive to produce heat from the flow of electrical current therethrough. The at least one heating element may be arranged as a susceptor to produce heat when penetrated by an alternating magnetic field. The heating system may be configured to heat a precursor to below 300 or 350 degrees C, including without combustion. The heating system may be provided within the aerosol generating component or within the device body.
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As used herein, an "information carrying medium" may include one or more arrangements for storage of information on any suitable medium. Examples include: a computer readable medium; a Radio Frequency Identification (RFID) transponder; codes encoding information, such as optical (e.g. a bar code or QR code) or mechanically read codes (e.g. a configuration of the absence or presents of cutouts to encode a bit, through which pins or a reader may be inserted).
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As used herein "heat-not-burn" (or "HNB" or "heated precursor") may refer to the heating of a precursor, typically tobacco, without combustion, or without substantial combustion (i.e. localised combustion may be experienced of limited portions of the precursor, including of less than 5% of the total volume).
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As used herein, "electrical circuitry" may refer to one or more electrical components, examples of which may include: an Application Specific Integrated Circuit (ASIC); electronic/electrical componentry (which may include combinations of transistors, resistors, capacitors, inductors etc); one or more processors; a non-transitory memory (e.g. implemented by one or more memory devices), that may store one or more software or firmware programs; a combinational logic circuit; interconnection of the aforesaid. The electrical circuitry may be located entirely at the device, or distributed between the device and/or on one or more external devices in communication with the device, e.g. as part of the system.
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As used herein, a "processing resource" (or "processor" or "controller") may refer to one or more units for processing data, examples of which may include an ASIC, microcontroller, FPGA, microprocessor, digital signal processor (DSP) capability, state machine or other suitable component. A processing resource may be configured to execute a computer program, e.g. which may take the form of machine readable instructions, which may be stored on a non-transitory memory and/or programmable logic. The processing resource may have various arrangements corresponding to those discussed for the circuitry, e.g. on-board and/or off board the apparatus as part of the system. As used herein, any machine executable instructions, or computer readable media, may be configured to cause a disclosed method to be carried out, e.g. by an aerosol generating apparatus or system as disclosed herein, and may therefore be used synonymously with the term method.
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As used herein, a "computer readable medium/media" (or "memory" or "data storage") may include any medium capable of storing a computer program, and may take the form of any conventional non-transitory memory, for example one or more of: random access memory (RAM); a CD; a hard drive; a solid state drive; a memory card; a DVD. The memory may have various arrangements corresponding to those discussed for the circuitry /processor. The present disclosure includes a computer readable medium configured to cause an apparatus or system disclosed herein to perform a method as disclosed herein.
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Referring to Fig. 1, an example aerosol generating apparatus 1 includes a power supply 2, for supply of electrical energy. The apparatus 1 includes an aerosol generating unit 4 that is driven by the power supply 2. The power supply 2 may include an electric power supply in the form of a battery and/or an electrical connection to an external power source. The apparatus 1 includes a precursor 6, which in use is aerosolised by the aerosol generating unit 4 to generate an aerosol. The apparatus 1 includes a delivery system 8 for delivery of the aerosol to a user.
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Electrical circuitry (not shown in figure 1) may be implemented to control the interoperability of the power supply 2 and aerosol generating unit 4.
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In variant examples, which are not illustrated, the power supply 2 may be omitted since, e.g. an aerosol generating unit implemented as an atomiser with flow expansion may not require a power supply.
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Fig. 2 shows an implementation of the apparatus 1 of Fig. 1, where the aerosol generating apparatus 1 is configured to generate aerosol by a heat-not-burn process.
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In this example, the apparatus 1 includes a device body 50 and a consumable 70.
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In this example, the body 50 includes the power supply 2 and a heating system 52. The heating system 52 includes at least one heating element 54. The body may additionally include any one or more of electrical circuitry 56, a memory 58, a wireless interface 60, one or more other components 62.
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The electrical circuitry 56 may include a processing resource 57 (or `controller') for controlling one or more operations of the body 50, e.g. based on instructions stored in the memory 58.
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The wireless interface 60 may be configured to communicate wirelessly with an external (e.g. mobile) device, e.g. via Bluetooth.
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The other component(s) 62 may include an actuator, one or more user interface devices configured to convey information to a user and/or a charging port, for example (see e.g. Fig. 5).
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The body 50 is configured to engage with the consumable 70 such that the at least one heating element 54 of the heating system 52 penetrates into the solid precursor 6 of the consumable. In use, a user may activate the aerosol generating apparatus 1 to cause the heating system 52 of the body 50 to cause the at least one heating element 54 to heat the solid precursor 6 of the consumable (without combusting it) by conductive heat transfer, to generate an aerosol which is inhaled by the user.
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Fig. 3 shows an example implementation of the aerosol generating device 1 of Fig. 2.
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As depicted in Fig. 3, the consumable 70 is implemented as a stick, which is engaged with the body 50 by inserting the stick into an aperture at a top end 53 of the body 50, which causes the at least one heating element 54 of the heating system 52 to penetrate into the solid precursor 6.
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The consumable 70 includes the solid precursor 6 proximal to the body 50, and a filter distal to the body 50. The filter serves as the mouthpiece of the consumable 70 and thus the apparatus 1 as a whole. The solid precursor 6 may be a reconstituted tobacco formulation.
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In this example, the body 50 includes a cap 51. In use the cap 51 is engaged at a top end 53 of the body 50. Although not apparent from Fig. 3, the cap 51 is moveable relative to the body 50. In particular, the cap 51 is slidable and can slide along a longitudinal axis of the body 50.
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The body 50 also includes an actuator 55 on an outer surface of the body 50. In this example, the actuator 55 has the form of a button.
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The body 50 also includes a user interface device configured to convey information to a user. Here, the user interface device is implemented as a plurality of lights 57, which may e.g. be configured to illuminate when the apparatus 1 is activated and/or to indicate a charging state of the power supply 2. Other user interface devices are possible, e.g. to convey information haptically or audibly to a user.
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The body may also include an airflow sensor which detects airflow in the aerosol generating apparatus 1 (e.g. caused by a user inhaling through the consumable 70). This may be used to count puffs, for example.
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In this example, the consumable 70 includes a flow path which transmits aerosol generated by the at least one heating element 54 to the mouthpiece of the consumable.
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In this example, the aerosol generating unit 4 is provided by the heating system 52 and the delivery system 8 is provided by the above-described flow path and mouthpiece of the consumable 70.
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Figs. 4 and 5 are side views of the heating system 52 included in the body 50. Figure 4 shows the heating system 52 with the consumable 70 received, while Figure 5 shows the heating system 52 without the consumable 70.
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Fig. 4 shows the consumable 70 is received into a precursor chamber 120 for heating by the heating system 52. Here, the heating system 52 is provided as an IR heating system 130 configured to heat the consumable 70 by emitting IR radiation, i.e. infrared radiation. The IR radiation which can be emitted by the IR heating system 130, and which is referred to as the total range of wavenumbers, may include radiation having wavenumbers in a range including at least 3600 to 800 inverse-centimetres, where the wavenumber corresponds to the inverse of wavelength. In the present disclosure wavenumbers are specified in units of "inverse-centimetres", which may also be denoted as cm-1 ("cm" with superscript "-1") or cm-1 (without superscript) or 1/cm. Ranges of wavenumbers are ordered in accordance with customary practice in infrared spectroscopy, according to which higher energies (corresponding to larger wavenumbers) are recorded towards the left on graphs and lower energies (corresponding to smaller wavenumbers) are recorded towards the right, such as the above range of "3600 to 800 inverse-centimetres".
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The aerosol generating apparatus 1 is operable by a user to initiate an aerosol session over which to generate aerosol from the consumable 70 using the IR heating system 130. The aerosol session may have a duration of, for example, at least three minutes and/or up to five minutes. A preheat phase may precede the aerosol session, wherein during the preheat phase the IR heating system 130 and/or the consumable 70 are brought to a desired operating temperature.
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The IR heating system 130 is configured to emit IR radiation having a total radiant power. The total radiant power corresponds to the power being emitted in the form of IR radiation across all wavenumbers being emitted by the IR heating system 130. During the aerosol session, the IR heating system 130 is configured to increase, relative to the total radiant power output by the IR heating system, radiant power of IR radiation emitted across a target range of wavenumbers. The target range of wavenumbers is contained in the total range of wavenumbers, i.e. corresponds to a subset of all wavenumbers which can be emitted by the IR heating system 130. Thus, the spectral power distribution of IR radiation emitted over the course of the aerosol session can be adjusted.
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The IR heating system 130 includes a plurality of heating elements 54 which are provided as IR emitters 132, 133 including a first IR emitter 132 and a second IR emitter 133. The IR emitters 132, 133 are arranged about the precursor chamber 120 to in use emit IR radiation into the precursor chamber 120 and so heat the consumable 70 located therein. The IR emitters 132, 133 are configured to emit different IR spectra and are independently controllable. Thus, in use the overall spectrum of IR radiation emitted by the IR heating system 130 can be controlled by controlling the IR emitters 132, 133. In particular, the radiant power of IR radiation emitted across the target range can be increased relative to the total radiant power by suitably supplying power to the IR emitters 132, 133.
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The first IR emitter 132 is configured to emit IR radiation predominantly in the target range of wavenumbers, such that increasing radiant power being output by the first IR emitter 132 results in increasing of radiant power predominantly within the target range. To a lesser extent also IR radiation outside of the target range may increase. Suitably, 50% or more of all radiant power being output by the first IR emitter 132 may be within the target range. In some examples, 60% or 70% of all radiant power output by the first IR emitter 132 may be within the target range.
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In some examples, the controller 57 is configured to control the IR heating system 130 to suitably increase radiant power across the target range, for example by controlling electrical power supplied to the plurality of IR emitters 132, 133.
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Figs. 6, 7 and 8 are graphs illustrating radiant power being output by the IR heating system 130. Fig. 6 shows an example wherein the total radiant power increases over the aerosol session, as may be used particularly where release of nicotine is targeted. Fig. 7 shows an example wherein the total radiant power is maintained over the aerosol session, which may also be particularly useful where release of nicotine is targeted. Fig. 8 shows an example wherein the total radiant power decreases over the aerosol session, as may be used particularly where release of water is targeted.
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In each of Figs. 6, 7 and 8, radiant power that is output by the first IR emitter 132 is represented by a solid line, radiant power that is output by the second IR emitter 133 is represented by a dotted line, and total radiant power that is output by the IR heating system 130 is represented by a dashed line.
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In Fig. 6, the second IR emitter 133 outputs a constant amount of radiant power over the entire aerosol session. By contrast, the first IR emitter 132 does not output power until 40% of the aerosol session has elapsed, at which point the first IR emitter 132 gradually increase output of radiant power. Radiant power of the first IR emitter 132 increases until radiant power plateaus upon elapsing of 70% of the aerosol session.
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In Fig. 7, the second IR emitter 133 outputs constant radiant power until 30% of the aerosol session has elapsed, at which point the radiant power output by the second IR emitter 133 gradually decreases for the remainder of the aerosol session and ultimately reaches zero. The first IR emitter 132 outputs zero radiant power at the beginning of the aerosol session until elapsing of 30% of the aerosol session, at which point the radiant power output of the first IR emitter 132 gradually increases until the end of the aerosol session.
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According to Fig. 7, the gradual decrease of radiant power by the second IR emitter 133 and the gradual increase of radiant power by the first IR emitter 132 are such that the total radiant power being output by the IR heating system 130 is constant throughout the aerosol session.
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In Fig. 8, a graph similar to that of Fig. 7, in that radiant power from the second IR emitter 133 gradually decreases and radiant power from the first IR emitter 132 gradually increases. However, according to Fig. 8 the total radiant power decreases during the aerosol session. Also, at the end of the aerosol session both IR emitters 132, 133 output non-zero radiant power.
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In some examples, the IR heating system 130 may be configured to target the release of nicotine and water vapour, for example by increasing radiant power across the range of wavenumbers from 3600 to 800 inverse-centimetres. In such examples, the IR heating system 130 may be configured to decrease total radiant power during the aerosol session to reduce an increase in perceived temperature as may be caused by increased release of water vapour.
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Fig. 9 is a graph of experimental data showing an absorbance spectrum of the consumable 70. The data has been obtained using Fourier-transform infrared spectroscopy ("FTIR" spectroscopy). The absorbance spectrum is recorded for IR radiation with wavenumbers in a range of approximately 4000 to 700.
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A first region of comparatively high absorbance is shown in Fig. 9 at wavenumbers around 3600 to 2600 inverse-centimetres. The first region has a first local maximum at around 3300 inverse-centimetres. The first region has a second local maximum at around 2900 inverse-centimetres.
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A second region of comparatively high absorbance is shown in Fig. 9 at wavenumbers around 1700 to 700 inverse-centimetres. The second region has a first local maximum at around 1400 inverse-centimetres; a second local maximum at around 1300 inverse-centimetres, a third local maximum at around 1150 inverse-centimetres, a fourth local maximum at around 1100 inverse-centimetres, a fifth local maximum at around 1150 inverse-centimetres, a sixth local maximum at round 1000 inverse-centimetres, and a seventh local maximum at around 900 inverse-centimetres.
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Fig. 9 illustrates that particular IR radiation of certain wavenumbers is preferentially absorbed by the consumable 70. Utilising the wavenumbers associated with greatest absorbency may improve heating of the consumable 70.
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The inventors observed that emitting IR radiation with wavenumbers in the first region (and particularly 3600 to 2900 inverse-centimetres) may increase the concentration of water vapour in the aerosol generated over the aerosol session. The inventors also observed that emitting IR radiation with wavenumbers in the second region (and particularly 1500 to 800 inverse-centimetres) may increase the concentration of nicotine in the aerosol generated over the aerosol session. As such, the concentration of water vapour and/or nicotine in the aerosol may be increased by targeting the first region and/or the second region.
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In some examples, the first IR emitter 132 is configured to emit IR radiation predominantly (e.g. at least 50%, or at least 60%, or at least 70%) in the first region or in the second region. In some examples, the first IR emitter 132 is configured to emit IR radiation predominantly in one of the first region or the second region, and the second IR emitter 133 is configured to emit IR radiation predominantly in the other of the first region or the second region, and a third IR emitter (not shown) is configured to emit IR radiation not predominantly in either of the first region and the second region.
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Fig. 10 illustrates a method of controlling the aerosol generating apparatus.
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The method includes a step S110 of providing the aerosol generating apparatus 1, wherein the aerosol generating apparatus 1 includes the precursor chamber 120 for receiving the aerosol precursor 70 and the IR heating system 130 to emit IR radiation across the total range of wavenumbers.
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The method includes a step S120 of initiating the aerosol session to cause generating of aerosol from the aerosol precursor 70 using the IR heating system 130.
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The method includes a step S130 of increasing, relative to the total radiant power output by the IR heating system, radiant power of IR radiation emitted across the target range of wavenumbers contained in the total range of wavenumbers to increase consistency of the aerosol generated over the aerosol session.
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The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
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While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.
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For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.
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Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.
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Throughout this specification, including the claims which follow, unless the context requires otherwise, the word "comprise" and "include", and variations such as "comprises", "comprising", and "including" will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.
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It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" in relation to a numerical value is optional and means for example +/- 10%.