Aerosol-generating device with multiple secondary airflow channels in mouthpiece

Abstract

The invention relates to an aerosol-generating device (10) comprising a heating chamber (14) for receiving a substrate portion containing aerosol-forming substrate. The aerosol-generating device further comprises a mouthpiece (12). A main airflow channel (18) is provided for drawing ambient air through the heating chamber (14) and into the mouthpiece (12). A secondary airflow channel (32) is provided in the mouthpiece (12) for drawing ambient air into the main airflow channel (18) downstream of the heating chamber (14) and in the mouthpiece (12). The secondary airflow channel (32) comprises multiple air outlets (46) for fluidly connecting the secondary airflow channel (32) with the main airflow channel (18). The invention further relates to an aerosol-generating system comprising the aerosol-generating device (10) and an aerosol-generating article (16) comprising aerosol-forming substrate.

Description

[0001] AEROSOL-GENERATING DEVICE WITH MULTIPLE SECONDARY AIRFLOW CHANNELS IN MOUTHPIECE

[0002] The present invention relates to an aerosol-generating device. The invention further relates to an aerosol-generating system comprising the aerosol-generating device and an aerosol-generating article comprising aerosol-forming substrate.

[0003] It is known to provide an aerosol-generating device for generating an inhalable vapor. Such devices may heat aerosol-forming substrate to a temperature at which one or more components of the aerosol-forming substrate are volatilised without burning the aerosol-forming substrate. Aerosol-forming substrate may be provided as part of an aerosol-generating article. The aerosol-generating article may have a rod shape for insertion of the aerosol-generating article into a cavity, such as a heating chamber, of the aerosol-generating device. A heating element may be arranged in or around the heating chamber for heating the aerosol-forming substrate once the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device. The aerosol-generating article may be inserted into the cavity. Subsequently, a mouthpiece may be attached to the cavity so that the aerosol-generating article is enclosed by the cavity and the mouthpiece. A user may subsequently draw upon the mouthpiece.

[0004] It would be desirable to have an aerosol-generating device with improved aerosol generation.

[0005] According to an embodiment of the invention there may be provided an aerosolgenerating device comprising a heating chamber for receiving a substrate portion containing aerosol-forming substrate. The aerosol-generating device may further comprise a mouthpiece. A main airflow channel may be provided for drawing ambient air through the heating chamber and into the mouthpiece. A secondary airflow channel may be provided in the mouthpiece for drawing ambient air into the main airflow channel downstream of the heating chamber and in the mouthpiece. The secondary airflow channel may comprise multiple air outlets for fluidly connecting the secondary airflow channel with the main airflow channel.

[0006] According to an embodiment of the invention there is provided an aerosol-generating device comprising a heating chamber for receiving a substrate portion containing aerosolforming substrate. The aerosol-generating device further comprises a mouthpiece. A main airflow channel is provided for drawing ambient air through the heating chamber and into the mouthpiece. A secondary airflow channel is provided in the mouthpiece for drawing ambient air into the main airflow channel downstream of the heating chamber and in the mouthpiece. The secondary airflow channel comprises multiple air outlets for fluidly connecting the secondary airflow channel with the main airflow channel. The secondary airflow channel may allow mixing of ambient air with air drawn through the main airflow channel of the aerosol-generating device. The dilution of the air being drawn through the main airflow channel of the aerosol-generating device with ambient air may allow cooling of the air and thereby allowing or improving aerosol formation. A similar effect may be achieved by the construction of aerosol-generating articles comprising aerosol-forming substrate. An aerosol-generating article may comprise a cooling section with perforations leading into a hollow tubular section for allowing the mixing of ambient air with air being drawn through the aerosol-generating article. However, this section is discarded with each aerosolgenerating article. It may thus be beneficial to move the cooling section where ambient air is drawn into the air stream into the aerosol-generating device. In this case, no discarding of such section is necessary so that the aerosol-generating article can essentially consist of the aerosol-forming substrate. The present invention allows this as the mouthpiece fulfills the role of dilution of the airflow by mixing with ambient air due to the provisioning of the secondary airflow channel in the mouthpiece. Further, moving the cooling portion into the mouthpiece from the aerosol-generating articles improves sustainability as the mouthpiece is a permanent part while aerosol-generating articles are discarded after being depleted.

[0007] Providing the secondary airflow channel with multiple air outlets may have additional benefits. The multiple air outlets may enable a more homogeneous mixing of ambient air with the air drawn through the main airflow channel.

[0008] The multiple air outlets may be arranged circumferentially surrounding the main airflow channel. The multiple air outlets may enter the main airflow channel at evenly spaced intervals.

[0009] Upstream of the multiple air outlets, the secondary airflow channel may split into corresponding multiple airflow channels. Each air outlet may be arranged at a transition portion between the secondary airflow channel and the main airflow channel. In other words, the air outlets may form the transition portion of the secondary airflow channel towards the main airflow channel.

[0010] The secondary airflow channel may extend at least partly laterally through the mouthpiece.

[0011] Arranging the secondary airflow channel at least partly or fully laterally through the mouthpiece may lead to the ambient air being drawn through the secondary airflow channel and into the main airflow channel to form a boundary airflow layer adjacent a sidewall of the main airflow channel. In other words, the ambient air being drawn through the secondary airflow channel and into the main airflow channel may lead to a sheath airflow of this ambient air from the secondary airflow channel around the central airflow through the main airflow channel. This may reduce potential aerosol deposition or condensation at the sidewall of the main airflow channel in the mouthpiece. The secondary airflow channel may extend at least partly or fully perpendicular to the main airflow channel. The secondary airflow channel may enter the mouthpiece from a sidewall of the mouthpiece. The secondary air inlet may be arranged in the sidewall of the mouthpiece.

[0012] The secondary airflow channel may be fluidly connected with the main airflow channel adjacent an upstream end of the mouthpiece. In other words, the secondary airflow channel may be fluidly connected with the main airflow channel adjacent a distal end of the mouthpiece. This may facilitate that the mixing of the ambient air from the secondary airflow channel with the air drawn through the main airflow channel happens at an upstream portion of the mouthpiece. This may enable aerosol formation and cooling of the airflow further downstream such that the generated aerosol exits the mouthpiece at the mouthpiece outlet with the appropriate droplet size of the aerosol and with the appropriate temperature for subsequent aerosol inhalation.

[0013] The aerosol-generating device may further comprise an inflow adjustment tool which may be configured to adjust the cross-sectional diameter of the secondary airflow channel thereby controlling the ratio of air being drawn through the secondary airflow channel and air being drawn through the main airflow channel. The inflow adjustment tool may adjust the resistance to draw (RTD) of the secondary airflow channel. The RTD of the secondary airflow channel in comparison with the RTD of the main airflow channel may lead to a different amount of the ratio of ambient air being drawn through the secondary airflow channel to air being drawn through the main airflow channel. Increasing the RTD of the secondary airflow channel will lower the amount of ambient air being drawn into the mouthpiece through the secondary airflow channel and decreasing the RTD of the secondary airflow channel will increase the amount of ambient air being drawn into the mouthpiece from the secondary airflow channel.

[0014] The inflow adjustment tool may enable customization of the user experience due to enabling the user to adjust the ratio of air being drawn through the secondary airflow channel and the main airflow channel. The introduction of more ambient air through the secondary airflow channel may dilute the generated aerosol and therefore lead to a smoother user experience. The introduction of less air through the secondary airflow channel may lead to less dilution of the generated aerosol and therefore to a stronger user experience.

[0015] The inflow adjustment tool may be mounted externally to the mouthpiece. The inflow adjustment tool may be mounted at the secondary air inlet. The inflow adjustment tool may comprise a rotating portion. The rotating portion of the inflow adjustment tool may decrease / increase the cross-sectional area of the secondary airflow channel when being rotated depending upon rotation direction.

[0016] The inflow adjustment tool may be configured rotatable around an axis perpendicular to a longitudinal axis of the aerosol-generating device. Rotation of the inflow adjustment tool may adjust the cross-sectional diameter of the secondary airflow channel.

[0017] The aerosol-generating device may further comprise a flavour portion fluidly connected with the main airflow channel of the mouthpiece.

[0018] The flavour portion may be arranged downstream of the aerosol forming chamber. The flavour portion may be arranged in the mouthpiece. The flavour portion may be fluidly connected with the main airflow channel such that aromatics from the flavour portion can be entrained in the airflow flowing through the airflow channel.

[0019] The flavour portion may be arranged in a tertiary airflow channel. The tertiary airflow channel may be fluidly connected with the secondary airflow channel.

[0020] The flavour portion may be configured as a replaceable flavour portion. Hence, after depletion of the flavour portion or if a different flavour is desired, the flavour portion can be replaced.

[0021] The flavour portion may be configured refillable. The flavour portion may have a flavour inlet. The flavour inlet may be arranged in a sidewall of the mouthpiece. The flavour inlet may allow refilling of the flavour portion.

[0022] The flavour portion may comprise an adsorbent material impregnated with flavour.

[0023] The aerosol-generating device may further comprise a flavour adjustment means. The flavour adjustment means may be configured to adjust the amount of airflow through the tertiary airflow channel by adjusting a minimum cross-sectional area of the tertiary airflow channel.

[0024] The flavour adjustment means may be configured to adjust the cross-sectional area of the tertiary airflow channel independent from the cross-sectional area of the main airflow channel and independent from the cross-sectional area of the secondary airflow channel. In other words, the flavour adjustment means may be configured to adjust the cross-sectional area of the tertiary airflow channel in isolation.

[0025] The flavour adjustment means may be configured user adjustable. Hence, the user can choose the amount of flavour added to the airstream.

[0026] The flavour adjustment means may comprise a flavour plug. The flavour plug may be removably insertable into the flavour adjustment means. The flavour plug may be removably insertable into a flavour recess of the flavour adjustment means. The flavour recess of the flavour adjustment means may be accessible from the outside of the mouthpiece for replacement of the flavour plug. Alternatively, the flavour adjustment means may consist of a flavour plug.

[0027] The flavour adjustment means may be arranged downstream of the merging portion between the secondary airflow channel and the main airflow channel. Alternatively, the flavour adjustment means may be arranged upstream of the merging portion between the secondary airflow channel and the main airflow channel. The later arrangement may improve the mixing of flavour with the airflow through the main airflow channel due to the downstream turbulent airflow by mixing the ambient air with the airflow of the main airflow channel.

[0028] The secondary airflow channel may be split into multiple airflow channels, preferably into 4 airflow channels.

[0029] Each airflow channel may terminate into an air outlet for fluidly connecting the respective airflow channel with the main airflow channel.

[0030] The multiple air outlets may be uniformly distributed around the main airflow channel.

[0031] The multiple air outlets may be fluidly connected with a ring-shaped portion of the secondary airflow channel surrounding the main airflow channel.

[0032] The ring-shaped portion of the secondary airflow channel may be coaxially arranged with the main airflow channel.

[0033] The aerosol-generating device may comprise a main body. The heating chamber may be arranged in the main body.

[0034] The main body may comprise further elements of the aerosol-generating device. Exemplarily, the main body may comprise a power supply, preferably a battery. The main body may comprise a controller. The main body may comprise a heating element. The controller may be configured to control supply of electrical power from the power supply to the heating element.

[0035] The heating element may be arranged at least partly or fully surrounding the heating chamber. The heating element may be an induction heating element. The heating element may comprise an induction coil. The heating element may further comprise a susceptor arranged within the induction coil. Alternatively, the susceptor may be part of the aerosolgenerating article. Alternatively, the heating element may be configured as a resistive heating element.

[0036] The aerosol-generating article may be sandwiched between a main body of the aerosol-generating device and the mouthpiece when the mouthpiece is closed.

[0037] The mouthpiece may be hingedly attached to the main body of the aerosol-generating device. The hinge between the mouthpiece and the main body may be arranged at a proximal end of the main body.

[0038] The heating chamber may be arranged upstream of the mouthpiece. The mouthpiece may be opened such that an aerosol-generating article comprising aerosol-forming substrate can be inserted into the heating chamber. Subsequently, the mouthpiece may be closed. The mouthpiece may close the heating chamber. The aerosol-generating article may be sandwiched between a main body of the aerosol-generating device and the mouthpiece when the mouthpiece is closed. The mouthpiece may hermetically close a proximal part of the heating chamber apart from an air outlet through which air can flow from the heating chamber into the mouthpiece.

[0039] The mouthpiece may be moved between an open position and a closed position. In the open position of the mouthpiece, a proximal opening of the heating chamber may be accessible for insertion and removal of aerosol-generating articles. In the closed position of the mouthpiece, the proximal opening of the heating chamber may be closed.

[0040] The mouthpiece may be arranged at a proximal end of the main body. The mouthpiece may be attached to the proximal end of the main body. The mouthpiece may be hingedly attached to the proximal end of the main body.

[0041] The mouthpiece may be configured replaceably attachable to the main body.

[0042] The mouthpiece may be replaceably attached to the main body by corresponding attachment means. For example, the mouthpiece may be replaceably attached to the main body by snap fit attachment means or bayonet attachment means. Generally, the mouthpiece may be replaceably attachable to the main body by form fit attachment means of friction fit attachment means or a combination of both.

[0043] A first airflow portion of the main airflow channel may be arranged in the main body. In other words, the main airflow channel may first run through the main body and into the heating chamber and subsequently into the mouthpiece. Finally, the air may be drawn through a mouthpiece outlet towards a mouth of a user for inhalation.

[0044] The main body may comprise a main air inlet for drawing ambient air into the first airflow portion of the main airflow channel. The main air inlet may be arranged at a sidewall of the main body. Alternatively, the main air inlet may be arranged at a distal end of the main body. The distal end of the main body may be the distal end of the aerosol-generating device.

[0045] The mouthpiece may comprise a secondary air inlet fluidly connected with the secondary airflow channel. The secondary air inlet may be provided in addition to the main air inlet. While the main air inlet is preferably arranged at the main body, the secondary air inlet may be arranged at the mouthpiece. Hence, the airflow through the main airflow channel may start at the main body by ambient air being drawn through the main air inlet and into the heating chamber, while the mouthpiece’s secondary airflow channel may supply ambient air to the main airflow channel downstream of the heating chamber within the mouthpiece.

[0046] The mouthpiece may comprise a second airflow portion of the main airflow channel. The secondary airflow channel may be fluidly connected with the second airflow portion of the main airflow channel. The secondary airflow channel may be fluidly connected with the second airflow portion of the main airflow channel. The second airflow portion may be downstream of the heating chamber. The second airflow portion may fluidly connect the heating chamber with the mouthpiece outlet. The second airflow portion of the main airflow channel may comprise an aerosol forming chamber. The aerosol forming chamber may be where the ambient air from the secondary airflow channel merges with the main airflow channel, more particularly with the second airflow portion of the main airflow channel. In this section, the ambient air may mix with the air from the heating chamber such that the air cools down and aerosol droplets form by condensation.

[0047] The aerosol forming chamber may have an inner diameter of between 7 mm and 20 mm, more preferably between 9 mm and 14 mm.

[0048] The aerosol forming chamber may have a larger diameter than the secondary airflow channel. The aerosol forming chamber may have a larger diameter than the first airflow portion of the main airflow channel. The aerosol forming chamber may be part of the second airflow portion of the main airflow channel.

[0049] The aerosol forming chamber may directly abut the heating chamber. In other words, when the mouthpiece is moved over the inserted aerosol-generating article received in the heating chamber, the aerosol forming chamber of the mouthpiece may directly abut the heating chamber. This arrangement may lead to the air being drawn through the heating chamber immediately being drawn into the aerosol forming chamber downstream of the heating chamber.

[0050] The second airflow portion of the main airflow channel may extend at least partly along or parallel to a longitudinal central axis of the mouthpiece.

[0051] The secondary airflow channel may be fluidly connected with the second airflow portion of the main airflow channel such as to create a turbulent mixing of air being drawn through the secondary airflow channel with the air being drawn through the second airflow portion of the main airflow channel.

[0052] Of the combined volume of air being drawn through the secondary airflow channel and the second airflow portion of the main airflow channel, between 40% and 80%, more preferably between 45% and 75%, more preferably between 50% and 70%, more preferably between 55% and 65%, most preferably 60%, of the air may be drawn through the second airflow portion of the main airflow channel.

[0053] Of the combined volume of air being drawn through the secondary airflow channel and the second airflow portion of the main airflow channel, between 20% and 60%, more preferably between 25% and 55%, more preferably between 30% and 50%, more preferably between 35% and 45%, most preferably 40%, of the air may be drawn through the secondary airflow channel.

[0054] This mixing ratio of ambient air from the secondary airflow channel with the air being drawn through the main airflow channel from the heating chamber may lead to an optimal cooling of the airflow and thus aerosol formation. The aerosol-forming substrate of the aerosol-generating article may be heated by the heat of the heating element within the heating chamber. Desirable components of the aerosolforming substrate may be liberated by the heat of the heating element. These volatilized components of the aerosol-forming substrate may be entrained in the airflow through the heating chamber. In the aerosol-forming chamber, this volatilized aerosol-forming substrate may condense due to the mixing of this airflow with the ambient air being drawn through the secondary airflow channel. As a consequence, aerosol droplets may form which may subsequently be drawn through the mouthpiece and out the mouthpiece through the mouthpiece outlet.

[0055] The second airflow portion of the main airflow channel may comprise an upstream constricted portion and a downstream expanded portion. An inner diameter of the upstream constricted portion may be smaller than an inner diameter of the downstream expanded portion. This may create a Venturi effect. The Venturi effect may increase airflow in the upstream constricted portion. The Venturi effect may further improve a turbulent mixing of the air in the downstream expanded portion. The secondary airflow channel may merge with the main airflow channel at or near the upstream constricted portion. This arrangement may thus improve the mixing of ambient air with the air being drawn through the main airflow channel from the heating chamber. The improved mixing of ambient air with the air being drawn through the main airflow channel from the heating chamber may lead to a more rapid cooling of the airflow through the main airflow channel and thus to an improved nucleation of aerosol (i.e. an improved aerosol formation).

[0056] In addition or alternatively to providing the main airflow channel with the upstream constricted portion and the downstream expanded portion in order to enhance nucleation of the aerosol, the mouthpiece material itself may be chosen with high thermal conductivity in order to facilitate more rapid cooling of the air being drawn through the mouthpiece. Hence, the mouthpiece may comprise or may preferably be made of one or more of: Peek, metal, glass, PTFE and PEI.

[0057] Between the upstream constricted portion and the downstream expanded portion, the sidewall of the main airflow channel may be inclined. This may improve the creation of a more turbulent airflow.

[0058] The secondary airflow channel may be fluidly connected with the main airflow channel adjacent an upstream end of the mouthpiece. In other words, the secondary airflow channel may be fluidly connected with the main airflow channel adjacent a distal end of the mouthpiece. This may facilitate that the mixing of the ambient air from the secondary airflow channel with the air drawn through the main airflow channel happens at an upstream portion of the mouthpiece. This may enable aerosol formation and cooling of the airflow further downstream such that the generated aerosol exits the mouthpiece at the mouthpiece outlet with the appropriate droplet size of the aerosol and with the appropriate temperature for subsequent aerosol inhalation.

[0059] A minimum inner diameter of the secondary airflow channel may be between 0.1 mm and 5 mm, preferably between 0.5 mm and 4 mm, preferably between 1 mm and 3 mm.

[0060] A minimum inner diameter of the main airflow channel may be between 5 mm and 15 mm, preferably between 7 mm and 12 mm.

[0061] The secondary airflow channel may comprise an outlet at the transition from the secondary airflow channel to the main airflow channel. The outlet may be arranged having an inclined outlet angle such that air exiting the secondary airflow channel through the outlet travels into the main airflow channel along an inclined direction. The inclined arrangement of the outlet may lead to a more turbulent mixing of ambient air being drawn through the secondary airflow channel with the air being drawn through the main airflow channel from the heating chamber.

[0062] A sidewall surrounding the main airflow channel of the mouthpiece may have a varying wall thickness. This may enable introduction of a Venturi effect portion. The Venturi effect portion may lead to an acceleration of airflow thereby improving mixing of the airflow, i.e. by this improved generation of vortices / turbulences in the airflow. A narrow portion of the main airflow channel may be arranged upstream of a wider portion of the main airflow channel. Independent of the provisioning of a Venturi effect portion, having a varying wall thickness may enable a more rapid cooling in a portion of the main airflow channel with a thinner wall thickness. In such a portion, the main airflow channel may have less insulation enabling a more rapid cooling of the air being drawn through this portion of the main airflow channel. For this reason, the sidewall of the main airflow channel may be made from a thermally conductive material.

[0063] The invention further relates to an aerosol-generating system comprising the aerosolgenerating device as described herein and an aerosol-generating article comprising aerosolforming substrate.

[0064] The aerosol-generating article may be configured as a planar aerosol-generating article.

[0065] The aerosol-generating article may have a rectangular cross-section.

[0066] As used herein, the terms ‘proximal’, ‘distal’, ‘downstream’ and ‘upstream’ are used to describe the relative positions of components, or portions of components, of the aerosolgenerating device in relation to the direction in which a user draws on the aerosol-generating device during use thereof.

[0067] The aerosol-generating device may comprise a mouth end through which in use an aerosol exits the aerosol-generating device and is delivered to a user. The mouth end may also be referred to as the proximal end. In use, a user draws on the proximal or mouth end of the aerosol-generating device in order to inhale an aerosol generated by the aerosolgenerating device. The mouth end may be configured as the mouthpiece as described herein. The aerosol-generating device comprises a distal end opposed to the proximal or mouth end. The proximal or mouth end of the aerosol-generating device may also be referred to as the downstream end and the distal end of the aerosol-generating device may also be referred to as the upstream end. Components, or portions of components, of the aerosol-generating device may be described as being upstream or downstream of one another based on their relative positions between the proximal, downstream or mouth end and the distal or upstream end of the aerosol-generating device.

[0068] As used herein, an ‘aerosol-generating device’ relates to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-forming substrate may be part of an aerosol-generating article, for example part of a smoking article. An aerosol-generating device may be a smoking device that interacts with an aerosol-forming substrate of an aerosolgenerating article to generate an aerosol that is directly inhalable into a user’s lungs thorough the user's mouth. An aerosol-generating device may be a holder. The device may be an electrically heated smoking device. The aerosol-generating device may comprise a housing, electric circuitry, a power supply, a heating chamber and a heating element.

[0069] As used herein with reference to the present invention, the term ‘smoking’ with reference to a device, article, system, substrate, or otherwise does not refer to conventional smoking in which an aerosol-forming substrate is fully or at least partially combusted. The aerosol-generating device of the present invention is arranged to heat the aerosol-forming substrate to a temperature below a combustion temperature of the aerosol-forming substrate, but at or above a temperature at which one or more volatile compounds of the aerosol-forming substrate are released to form an inhalable aerosol.

[0070] The aerosol-generating device may comprise electric circuitry. The electric circuitry may comprise a microprocessor, which may be a programmable microprocessor. The microprocessor may be part of a controller. The electric circuitry may comprise further electronic components. The electric circuitry may be configured to regulate a supply of power to the heating element. Power may be supplied to the heating element continuously following activation of the aerosol-generating device or may be supplied intermittently, such as on a puff- by-puff basis. The power may be supplied to the heating element in the form of pulses of electrical current. The electric circuitry may be configured to monitor the electrical resistance of the heating element, and preferably to control the supply of power to the heating element dependent on the electrical resistance of the heating element.

[0071] The aerosol-generating device may comprise a power supply, typically a battery, within a main body of the aerosol-generating device. In one embodiment, the power supply is a Lithium-ion battery. Alternatively, the power supply may be a Nickel-metal hydride battery, a Nickel cadmium battery, or a Lithium based battery, for example a Lithium-Cobalt, a Lithium- Iron-Phosphate, Lithium Titanate or a Lithium-Polymer battery. As an alternative, the power supply may be another form of charge storage device such as a capacitor. The power supply may require recharging and may have a capacity that enables to store enough energy for one or more usage experiences; for example, the power supply may have sufficient capacity to continuously generate aerosol for a period of around six minutes or for a period of a multiple of six minutes. In another example, the power supply may have sufficient capacity to provide a predetermined number of puffs or discrete activations of the heating element.

[0072] The heating chamber, also denoted as cavity, of the aerosol-generating device may have an open end into which the aerosol-generating article is inserted. The open end may be a proximal end. The heating chamber may have a closed end opposite the open end. The closed end may be the base of the heating chamber. The closed end may be closed except for the provision of air apertures arranged in the base. The base of the heating chamber may be flat. The base of the heating chamber may be circular. The base of the heating chamber may be arranged upstream of the heating chamber. The open end may be arranged downstream of the heating chamber. The heating chamber may have an elongate extension. The heating chamber may have a longitudinal central axis. A longitudinal direction may be the direction extending between the open and closed ends along the longitudinal central axis. The longitudinal central axis of the heating chamber may be parallel to the longitudinal axis of the aerosol-generating device.

[0073] The heating chamber may have a cylindrical shape. The heating chamber may have a hollow cylindrical shape. The heating chamber may have a shape corresponding to the shape of the aerosol-generating article to be received in the heating chamber. The heating chamber may have a circular cross-section. The heating chamber may have an elliptical or rectangular cross-section. The heating chamber may have an inner diameter corresponding to the outer diameter of the aerosol-generating article.

[0074] An airflow channel may run through the heating chamber. Ambient air may be drawn into the aerosol-generating device, into the heating chamber and towards the user through the airflow channel. Downstream of the heating chamber, the mouthpiece may be arranged. The airflow channel may extend through the mouthpiece.

[0075] In any of the aspects of the disclosure, the heating element may comprise an electrically resistive material. Suitable electrically resistive materials include but are not limited to: semiconductors such as doped ceramics, electrically "conductive" ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys and composite materials made of a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum platinum, gold and silver. Examples of suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminium- titanium- zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese-, gold- and iron-containing alloys, and super-alloys based on nickel, iron, cobalt, stainless steel, Timetai® and iron-manganese-aluminium based alloys. In composite materials, the electrically resistive material may optionally be embedded in, encapsulated or coated with an insulating material or vice-versa, depending on the kinetics of energy transfer and the external physicochemical properties required.

[0076] As described, in any of the aspects of the disclosure, the heating element may be part of an aerosol-generating device. The aerosol-generating device may comprise an internal heating element or an external heating element, or both internal and external heating elements, where "internal" and "external" refer to the aerosol-forming substrate. An internal heating element may take any suitable form. For example, an internal heating element may take the form of a heating blade. Alternatively, the internal heater may take the form of a casing or substrate having different electro-conductive portions, or an electrically resistive metallic tube. Alternatively, the internal heating element may be one or more heating needles or rods that run through the center of the aerosol-forming substrate. Other alternatives include a heating wire or filament, for example a Ni-Cr (Nickel-Chromium), platinum, tungsten or alloy wire or a heating plate. Optionally, the internal heating element may be deposited in or on a rigid carrier material. In one such embodiment, the electrically resistive heating element may be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track on a suitable insulating material, such as ceramic material, and then sandwiched in another insulating material, such as a glass. Heaters formed in this manner may be used to both heat and monitor the temperature of the heating elements during operation.

[0077] An external heating element may take any suitable form. For example, an external heating element may take the form of one or more flexible heating foils on a dielectric substrate, such as polyimide. The flexible heating foils can be shaped to conform to the perimeter of the substrate receiving heating chamber. Alternatively, an external heating element may take the form of a metallic grid or grids, a flexible printed circuit board, a molded interconnect device (MID), ceramic heater, flexible carbon fibre heater or may be formed using a coating technique, such as plasma vapour deposition, on a suitable shaped substrate. An external heating element may also be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track between two layers of suitable insulating materials. An external heating element formed in this manner may be used to both heat and monitor the temperature of the external heating element during operation. As an alternative to an electrically resistive heating element, the heating element may be configured as an induction heating element. The induction heating element may comprise an induction coil and a susceptor. In general, a susceptor is a material that is capable of generating heat, when penetrated by an alternating magnetic field. When located in an alternating magnetic field. If the susceptor is conductive, then typically eddy currents are induced by the alternating magnetic field. If the susceptor is magnetic, then typically another effect that contributes to the heating is commonly referred to hysteresis losses. Hysteresis losses occur mainly due to the movement of the magnetic domain blocks within the susceptor, because the magnetic orientation of these will align with the magnetic induction field, which alternates. Another effect contributing to the hysteresis loss is when the magnetic domains will grow or shrink within the susceptor. Commonly all these changes in the susceptor that happen on a nano-scale or below are referred to as “hysteresis losses”, because they produce heat in the susceptor. Hence, if the susceptor is both magnetic and electrically conductive, both hysteresis losses and the generation of eddy currents will contribute to the heating of the susceptor. If the susceptor is magnetic, but not conductive, then hysteresis losses will be the only means by which the susceptor will heat, when penetrated by an alternating magnetic field. According to the invention, the susceptor may be electrically conductive or magnetic or both electrically conductive and magnetic. An alternating magnetic field generated by one or several induction coils heat the susceptor, which then transfers the heat to the aerosol-forming substrate, such that an aerosol is formed. The heat transfer may be mainly by conduction of heat. Such a transfer of heat is best, if the susceptor is in close thermal contact with the aerosol-forming substrate.

[0078] As used herein, the term ‘aerosol-generating article’ refers to an article comprising an aerosol-forming substrate that is capable of releasing volatile compounds that can form an aerosol. For example, an aerosol-generating article may be a smoking article that generates an aerosol that is directly inhalable into a user’s lungs through the user's mouth. An aerosolgenerating article may be disposable.

[0079] As used herein, the term ‘aerosol-forming substrate’ relates to a substrate capable of releasing one or more volatile compounds that can form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. An aerosol-forming substrate may conveniently be part of an aerosol-generating article or smoking article.

[0080] The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosolforming substrate may comprise both solid and liquid components. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds which are released from the substrate upon heating. The aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may comprise an aerosol former that facilitates the formation of a dense and stable aerosol. Examples of suitable aerosol formers are glycerine and propylene glycol.

[0081] The aerosol-generating substrate preferably comprises homogenised tobacco material, an aerosol-former and water. Providing homogenised tobacco material may improve aerosol generation, the nicotine content and the flavour profile of the aerosol generated during heating of the aerosol-generating article. Specifically, the process of making homogenised tobacco involves grinding tobacco leaf, which more effectively enables the release of nicotine and flavours upon heating.

[0082] Below, there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0083] Example 1. An aerosol-generating device comprising: a heating chamber for receiving a substrate portion containing aerosol-forming substrate, and a mouthpiece, wherein a main airflow channel is provided for drawing ambient air through the heating chamber and into the mouthpiece, wherein a secondary airflow channel is provided in the mouthpiece for drawing ambient air into the main airflow channel downstream of the heating chamber and in the mouthpiece, and wherein the secondary airflow channel comprises multiple air outlets for fluidly connecting the secondary airflow channel with the main airflow channel.

[0084] Example 2. The aerosol-generating device according to example 1 , wherein the secondary airflow channel extends at least partly laterally through the mouthpiece.

[0085] Example 3. The aerosol-generating device according to any of the preceding examples, wherein the aerosol-generating device further comprises an inflow adjustment tool which is configured to adjust the cross-sectional diameter of the secondary airflow channel thereby controlling the ratio of air being drawn through the secondary airflow channel and air being drawn through the main airflow channel.

[0086] Example 4. The aerosol-generating device according to example 3, wherein the inflow adjustment tool is configured rotatable around an axis perpendicular to a longitudinal axis of the aerosol-generating device.

[0087] Example 5. The aerosol-generating device according to example 4, wherein rotation of the inflow adjustment tool adjusts the cross-sectional diameter of the secondary airflow channel. Example 6. The aerosol-generating device according to any of the preceding examples, wherein the aerosol-generating device further comprises a flavour portion fluidly connected with the main airflow channel of the mouthpiece.

[0088] Example 7. The aerosol-generating device according to example 6, wherein the flavour portion is arranged in a tertiary airflow channel, wherein the tertiary airflow channel is fluidly connected with the secondary airflow channel.

[0089] Example 8. The aerosol-generating device according to example 7, wherein the aerosol-generating device further comprises a flavour adjustment means, wherein the flavour adjustment means is configured to adjust the amount of airflow through the tertiary airflow channel by adjusting a minimum cross-sectional area of the tertiary airflow channel.

[0090] Example 9. The aerosol-generating device according to any of examples 6 to 8, wherein the flavour portion comprises an adsorbent material impregnated with flavour

[0091] Example 10. The aerosol-generating device according to any of the preceding examples, wherein the secondary airflow channel is split into multiple airflow channels, preferably into 4 airflow channels.

[0092] Example 11. The aerosol-generating device according to 10, wherein each airflow channel terminates into an air outlet for fluidly connecting the respective airflow channel with the main airflow channel.

[0093] Example 12. The aerosol-generating device according to any of the preceding examples, wherein the multiple air outlets are uniformly distributed around the main airflow channel.

[0094] Example 13. The aerosol-generating device according to any of the preceding examples, wherein the multiple air outlets are fluidly connected with a ring-shaped portion of the secondary airflow channel surrounding the main airflow channel.

[0095] Example 14. The aerosol-generating device according to any of the preceding examples, wherein the aerosol-generating device comprises a main body, and wherein the heating chamber is arranged in the main body.

[0096] Example 15. The aerosol-generating device according to example 14, wherein the mouthpiece is hingedly attached to the main body of the aerosol-generating device.

[0097] Example 16. The aerosol-generating device according to example 14, wherein the mouthpiece is configured replaceably attachable to the main body.

[0098] Example 17. The aerosol-generating device according to any of examples 14 to 16, wherein a first airflow portion of the main airflow channel is arranged in the main body.

[0099] Example 18. The aerosol-generating device according to example 17, wherein the main body comprises a main air inlet for drawing ambient air into the first airflow portion of the main airflow channel. Example 19. The aerosol-generating device according to any of the preceding examples, wherein the mouthpiece comprises a secondary air inlet fluidly connected with the secondary airflow channel.

[0100] Example 20. The aerosol-generating device according to any of the preceding examples, wherein the mouthpiece comprises a second airflow portion of the main airflow channel, wherein the secondary airflow channel is fluidly connected with the second airflow portion of the main airflow channel.

[0101] Example 21. The aerosol-generating device according to example 20, wherein the second airflow portion of the main airflow channel comprises an aerosol forming chamber, preferably wherein the aerosol forming chamber has an inner diameter of between 7 mm and 20 mm, more preferably between 9 mm and 14 mm.

[0102] Example 22. The aerosol-generating device according to example 21 , wherein the aerosol forming chamber directly abuts the heating chamber.

[0103] Example 23. The aerosol-generating device according to any of examples 20 to 22, wherein the second airflow portion of the main airflow channel extends at least partly along or parallel to a longitudinal central axis of the mouthpiece.

[0104] Example 24. The aerosol-generating device according to any of examples 20 to 23, wherein the secondary airflow channel is fluidly connected with the second airflow portion of the main airflow channel such as to create a turbulent mixing of air being drawn through the secondary airflow channel with the air being drawn through the second airflow portion of the main airflow channel.

[0105] Example 25. The aerosol-generating device according to any of examples 20 to 24, wherein, of the combined volume of air being drawn through the secondary airflow channel and the second airflow portion of the main airflow channel, between 40% and 80%, more preferably between 45% and 75%, more preferably between 50% and 70%, more preferably between 55% and 65%, most preferably 60%, of the air is drawn through the second airflow portion of the main airflow channel.

[0106] Example 26. The aerosol-generating device according to any of examples 20 to 25, wherein, of the combined volume of air being drawn through the secondary airflow channel and the second airflow portion of the main airflow channel, between 20% and 60%, more preferably between 25% and 55%, more preferably between 30% and 50%, more preferably between 35% and 45%, most preferably 40%, of the air is drawn through the secondary airflow channel.

[0107] Example 27. The aerosol-generating device according to any of examples 20 to 26, wherein the second airflow portion of the main airflow channel comprises an upstream constricted portion and a downstream expanded portion, wherein an inner diameter of the upstream constricted portion is smaller than an inner diameter of the downstream expanded portion.

[0108] Example 28. The aerosol-generating device according to any of the preceding examples, wherein the secondary airflow channel is fluidly connected with the main airflow channel adjacent an upstream end of the mouthpiece.

[0109] Example 29. The aerosol-generating device according to any of the preceding examples, wherein a minimum inner diameter of the secondary airflow channel is between 0.1 mm and 5 mm, preferably between 0.5 mm and 4 mm, preferably between 1 mm and 3 mm.

[0110] Example 30. The aerosol-generating device according to any of the preceding examples, wherein a minimum inner diameter of the main airflow channel is between 5 mm and 15 mm, preferably between 7 mm and 12 mm.

[0111] Example 31. The aerosol-generating device according to any of the preceding examples, wherein the secondary airflow channel comprises an outlet at the transition from the secondary airflow channel to the main airflow channel, wherein the outlet is arranged having an inclined outlet angle such that air exiting the secondary airflow channel through the outlet travels into the main airflow channel along an inclined direction.

[0112] Example 32. The aerosol-generating device according to any of the preceding examples, wherein a sidewall surrounding the main airflow channel of the mouthpiece has a varying wall thickness.

[0113] Example 33. An aerosol-generating system comprising the aerosol-generating device according to any of the preceding examples and an aerosol-generating article comprising aerosol-forming substrate.

[0114] Example 34. The aerosol-generating system according to example 33, wherein the aerosol-generating article is configured as a planar aerosol-generating article.

[0115] Example 35. The aerosol-generating system according to example 33 or 34, wherein the aerosol-generating article has a rectangular cross-section.

[0116] Features described in relation to one embodiment may equally be applied to other embodiments of the invention.

[0117] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0118] Fig. 1 shows a sectional side view of a proximal portion of an aerosol-generating device comprising a mouthpiece;

[0119] Fig. 2 shows the mouthpiece having an aerosol forming chamber having an increased inner diameter; Fig. 3 shows a hingedly attachment of the mouthpiece to a main body of the aerosolgenerating device;

[0120] Fig. 4 shows the aerosol forming chamber comprising a Venturi portion;

[0121] Fig. 5 shows the mouthpiece with angled secondary airflow channels;

[0122] Fig. 6 shows a different view of a second portion of the main airflow channel and of the secondary airflow channel;

[0123] Fig. 7 shows an inflow adjustment tool;

[0124] Figs. 8A to 8C show embodiments including a flavour portion;

[0125] Fig. 9 shows an inflow adjustment tool and the secondary airflow channel split into multiple airflow channels fluidly connected with multiple air outlets; and

[0126] Fig. 10 shows a different view of the inflow adjustment tool.

[0127] Figure 1 shows a proximal portion of an aerosol-generating device 10 comprising a mouthpiece 12. The aerosol-generating device 10 comprises a heating chamber 14. An aerosol-generating article 16 comprising aerosol-forming substrate is received in the heating chamber 14. The heating chamber 14 is arranged in the main body 22 of the aerosolgenerating device 10. The mouthpiece 12 is configured removably attachable or hingedly attached to the main body 22. Between the main body 22 of the aerosol-generating device 10 at the mouthpiece 12, a connection section 24 may be arranged.

[0128] A heating element (not shown) of the aerosol-generating device 10 is configured for heating the aerosol-forming substrate of the aerosol-generating article 16. The heating element is arranged in the main body 22. Exemplarily, the heating element may comprise an induction coil (not shown) at least partly surrounding the heating chamber 14 while the aerosolgenerating article 16 comprises a susceptor (not shown) embedded within the aerosol-forming substrate.

[0129] The mouthpiece 12 comprises a main airflow channel 18. The main airflow channel 18 runs along a longitudinal central axis 20 of the mouthpiece 12. Ambient air is drawn into the main airflow channel 18 through a main air inlet (not shown) of the aerosol-generating device 10. The main airflow channel 18 arranged in the main body 22 of the aerosol-generating device 10 may be referred to as first portion 26 of the main airflow channel 18. The main airflow channel 18 arranged in the mouthpiece 12 of the aerosol-generating device 10 may be referred to as second portion 28 of the main airflow channel 18. In other words, ambient air is drawn into the first portion 26 of the main airflow channel 18 through the main air inlet in the main body 22 of the aerosol-generating device 10. The first portion 26 of the main airflow channel 18 fluidly connects the main air inlet with the heating chamber 14. Hence, the air is drawn through the main air inlet, through the first portion 26 of the main airflow channel 18 and into the heating chamber 14. Downstream of the heating chamber 14, the air enters the mouthpiece 12. Particularly, the air enters the second portion 28 of the main airflow channel 18 downstream of the heating chamber 14.

[0130] The second portion 28 of the main airflow channel 18 arranged in the mouthpiece 12 is arranged directly abutting the heating chamber 14 of the main body 22 of the aerosolgenerating device 10. In other words, the heating chamber 14 is arranged at a proximal end of the main body 22 of the aerosol-generating device 10 so that the air enters the mouthpiece 12 after exiting the heating chamber 14.

[0131] This section of the second portion 28 of the main airflow channel 18 adjacent the heating chamber 14, i.e. the upstream portion of the second portion 28 of the main airflow channel 18, may be referred to as aerosol forming chamber 34. The reason for this is that ambient air is drawn into this portion of the second portion 28 of the main airflow channel 18 through a secondary air inlet 30. The secondary air inlet 30 is arranged in a sidewall of the mouthpiece 12. The secondary air inlet 30 is fluidly connected with a secondary airflow channel 32. The secondary airflow channel 32 fluidly connects the secondary air inlet 30 with the second portion 28 of the main airflow channel 18. The secondary airflow channel 32 is arranged in the mouthpiece 12. The secondary airflow channel 32 is arranged perpendicular to the second portion 28 of the main airflow channel 18. The secondary airflow channel 32 has a lateral extension.

[0132] The ambient air drawn into the second portion 28 of the main airflow channel 18 through the secondary airflow channel 32 leads to a turbulent mixing of ambient air with the air coming from the heating chamber 14. This leads to a cooling of the airflow which in turn leads to aerosol formation due to condensation of vaporized aerosol-forming substrate entrained in the airflow coming from the heating chamber 14. This construction foregoes the need of a separate cooling section in the aerosol-generating article 16 which can therefore essentially consist of a substrate portion containing the aerosol-forming substrate.

[0133] Figure 2 shows an embodiment in which the aerosol forming chamber 34 has a larger diameter in comparison to the rest of the second portion 28 of the main airflow channel 18. Particularly, the second portion 28 of the main airflow channel 18 downstream of the aerosol forming chamber 34 has a reduced inner diameter comparison with the inner diameter of the aerosol forming chamber 34.

[0134] Figure 3 shows the hingedly attachment of the mouthpiece 12 to the main body 22 of the aerosol-generating device 10. In more detail, Figure 3 shows an open position of the mouthpiece 12 in which the heating chamber 14 of the main body 22 of the aerosol-generating device 10 is exposed for receiving the aerosol-generating article 16 comprising the aerosolforming substrate. After insertion of the aerosol-generating article 16 into the heating chamber 14 of the main body 22 of the aerosol-generating device 10, the mouthpiece 12 can be closed. After closing of the mouthpiece 12, the aerosol-generating article 16 is sandwiched between the main body 22 and the mouthpiece 12. After closing of the mouthpiece 12, the user experience can start by activation of the heating element of the aerosol-generating device 10.

[0135] Figure 4 shows a further embodiment in which the aerosol forming chamber 34 is configured as a Venturi portion. In more detail, the inner diameter of the aerosol forming chamber 34 is reduced in comparison to the downstream portion of the second portion 28 of the main airflow channel 18. More specifically, the portion of the aerosol forming chamber 34 in which the ambient air is drawn into through the secondary airflow channel 32 is constricted in comparison to the rest of the second portion 28 of the main airflow channel 18. This leads to an acceleration of the airflow towards the second portion 28 of the main airflow channel 18. The acceleration of the airflow leads to a more turbulent mixing of the ambient air with the air drawn from the heating chamber 14 and carrying this volatilized aerosol-forming substrate. The more turbulent mixing leads to an improved aerosol generation.

[0136] Figure 5 shows a configuration which the secondary airflow channel 32 is inclined with respect to a lateral direction. In other words, the secondary airflow channel 32 has an angle configuration and directs the ambient air into the aerosol forming chamber 34 at an angle. This leads to a better mixing of the ambient air from the secondary airflow channel 32 with the air being drawn from the heating chamber 14 in the aerosol forming chamber 34.

[0137] Figure 6 shows a different view of the aerosol-generating article 16 and the downstream second portion 28 of the main airflow channel 18. In this embodiment, the part of the second portion 28 of the main airflow channel 18 abutting the heating chamber 14 in which the aerosolgenerating article 16 is arranged is constricted with respect to the downstream part of the second portion 28 of the main airflow channel 18. This leads to a Venturi effect in the second portion 28 of the main airflow channel 18 and an acceleration of the airflow in the aerosol forming chamber 34. Further, a radial thickness of a mouthpiece wall of the mouthpiece 12 at the second portion 28 of the main airflow channel 18 has been chosen such to ensure a fast heat loss through the mouthpiece wall (faster cooling effect to create aerosol). The length of the second portion 28 of the main airflow channel 18 has been designed to minimize the deposition of unwanted compounds on the mouthpiece wall.

[0138] Figure 7 shows an inflow adjustment tool 36. The inflow adjustment tool 36 is configured to adjust the cross-sectional diameter of the secondary airflow channel 32. The adjustment of the cross-sectional diameter of the secondary airflow channel 32 is controlling the ratio of air being drawn through the secondary airflow channel 32 and air being drawn through the main airflow channel 18 from the heating chamber 14. For facilitating the adjustment of the cross-sectional diameter of the secondary airflow channel 32, the inflow adjustment tool 36 may comprise a rotatable component 38. The rotatable component 38 is arranged such that rotation of the rotatable component 38 modifies the cross-sectional diameter of the secondary airflow channel 32. The inflow adjustment tool 36 may be mounted on the mouthpiece 12 at the secondary air inlet 30.

[0139] Figures 8A to 8C show an embodiment of the aerosol-generating device 10 in which the inflow adjustment tool 36 is illustratively attached to the secondary air inlet 30. Additionally, Figures 8A to 8C show a flavour portion 40. The flavour portion 40 can be incorporated into the inflow adjustment tool 36 as shown in Figure 8A. In this way, the user may adjust the inflow of ambient air into the secondary airflow channel 32 by adjusting the inflow adjustment tool 36. At the same time, a user can adjust the amount of flavour being introduced into the air stream. Alternatively, as shown in Figure 8B, the flavour portion 40 can be arranged downstream of the inflow adjustment tool 36 and downstream of the aerosol forming chamber 34. As a further alternative, as shown in Figure 8C, the flavour portion 40 can be arranged upstream of the aerosol forming chamber 34. The later arrangement has the advantage of improved flavour mixing with the aerosol due to the turbulent airflow in the aerosol forming chamber 34 due to the introduction of ambient air through the secondary airflow channel 32. It should be noted that the provisioning of the flavour portion 40 is independent of the provisioning of the inflow adjustment tool 36. In other words, the flavour portion 40 can be provided as shown in any of Figures 8A to 8C without the need of the presence of an inflow adjustment tool 36.

[0140] Generally, for all embodiments, a single secondary air inlet 30 may be provided. The single secondary air inlet 30 may be fluidly connected with a single secondary airflow channel 32 for allowing inflow of ambient air into the aerosol forming chamber 34. Alternatively, more than one secondary air inlet 30 may be provided. For each individual secondary air inlet 30, separate secondary airflow channel 32s may be provided fluidly connecting the connecting the individual secondary air inlet 30 with the aerosol forming chamber 34. As a further alternative, a single secondary air inlet 30 is provided. However, downstream of the single secondary air inlet 30, the secondary airflow channel 32 may split into multiple secondary airflow channel 32s which ultimately terminate into the aerosol forming chamber 34.

[0141] Figure 9 shows a cross-sectional view of the inflow adjustment tool 36. The inflow adjustment tool 36 is arranged comprising the secondary air inlet 30. Further, the flavor portion 40 is incorporated into the inflow adjustment tool 36. In the embodiment shown in figure 9, the flavor portion 40 is split into two flavor portions 40. However, the flavor portion 40 could be configured as a single portion or more than two flavor portions.

[0142] The secondary air inlet 30 is fluidly connected with the secondary airflow channel 32. The secondary airflow channel 32 extends from the secondary air inlet 30 towards the main airflow channel 18. The secondary airflow channel 32 partly extends through the inflow adjustment tool 36. The flavor portion 40 is fluidly connected with the secondary airflow channel 32 by means of tertiary airflow channels 42. The tertiary airflow channels 42 are fluidly connected with tertiary air inlets 54 shown in below described Figure 10. When the tertiary air inlets 54 are opened by appropriate rotation of the inflow adjustment tool 36, ambient air flows from the tertiary air inlets 54 into the tertiary airflow channels 42, over the flavor portions 40 and into the secondary airflow channel 32. Due to the secondary air inlet 30 being also open at this rotation of the inflow adjustment tool 36, ambient air from the secondary air inlet 30 is also drawn into the secondary airflow channel 32. The mix of ambient air being drawn through the secondary airflow inlet 30 and ambient air carrying flavor from the flavor portions 40 and drawn through the tertiary airflow inlets 54 mix in the secondary airflow channel 32.

[0143] Figure 9 further shows the downstream configuration of the secondary airflow channel 32 after the inflow adjustment tool 36 and within the mouthpiece. The secondary airflow channel 32 in this portion of the secondary airflow channel 32 is split into multiple (in this example two) airflow channels 44 that are configured ring-shaped. The ring-shaped configuration of the secondary airflow channel 32 facilitates that the air is distributed uniformly around the main airflow channel 18. The fluid connection between the multiple airflow channels 44 and the main airflow channel is facilitated by multiple air outlets 46. The multiple air outlets 46 are part of the secondary airflow channel 32 fluidly connecting the secondary airflow channel 32 with the main airflow channel 18. The multiple air outlets 46 have a lateral extension. The multiple air outlets 46 are uniformly arranged around the main airflow channel 18. Preferably, four multiple air outlets 46 are provided. However, more than four air outlets 46 or less than four air outlets 46 can be provided. For example, three air outlets 46 could be provided of five air outlets 46 could be provided.

[0144] Figure 10 shows the inflow adjustment tool 36 seen from the outside of the mouthpiece 12. Particularly, figure 10 shows the secondary air inlet 30. Figure 10 also shows a user actuatable knob 48 utilized for rotating the inflow adjustment tool 36, more precisely an internal cylinder 50 of the inflow adjustment tool 36 such as to rotate the entrance to the secondary air inlet 30 relative to an outside housing 52 of the inflow adjustment tool 36 in order to open / close the secondary air inlet 30. Figure 10 further shows the tertiary air inlets 54 enabling airflow into the tertiary airflow channels 42. The inflow adjustment tool 36 preferably comprises a first (rotation) position in which the secondary air inlet 30 is open and in which the tertiary air inlets 54 are closed. In this position, ambient air is drawn through the secondary air inlet 30 into the secondary airflow channel 32 without additional flavor. The inflow adjustment tool 36 further comprises a second (rotation) position in which the secondary air inlet 30 is open and in which the tertiary air inlets 54 are open. In this position, ambient air is drawn both through the secondary air inlet 30 as well as through the tertiary air inlets 54 into the secondary airflow channel 32 with the addition of flavor. The inflow adjustment tool 36 further comprises a third (rotation) position in which both the secondary air inlet 30 is closed and in which the tertiary air inlets 54 are closed. Preferably, this is a position in which the aerosol-generating device 10 is not in use as ambient air cannot be drawn into the secondary airflow channel 32.

Claims

CLAIMS1. An aerosol-generating device comprising: a heating chamber for receiving a substrate portion containing aerosol-forming substrate, and a mouthpiece, wherein a main airflow channel is provided for drawing ambient air through the heating chamber and into the mouthpiece, wherein a secondary airflow channel is provided in the mouthpiece for drawing ambient air into the main airflow channel downstream of the heating chamber and in the mouthpiece, and wherein the secondary airflow channel comprises multiple air outlets for fluidly connecting the secondary airflow channel with the main airflow channel.

2. The aerosol-generating device according to claim 1, wherein the secondary airflow channel extends at least partly laterally through the mouthpiece.

3. The aerosol-generating device according to any of the preceding claims, wherein the aerosol-generating device further comprises an inflow adjustment tool which is configured to adjust the cross-sectional diameter of the secondary airflow channel thereby controlling the ratio of air being drawn through the secondary airflow channel and air being drawn through the main airflow channel.

4. The aerosol-generating device according to claim 3, wherein the inflow adjustment tool is configured rotatable around an axis perpendicular to a longitudinal axis of the aerosol-generating device.

5. The aerosol-generating device according to claim 4, wherein rotation of the inflow adjustment tool adjusts the cross-sectional diameter of the secondary airflow channel.

6. The aerosol-generating device according to any of the preceding claims, wherein the aerosol-generating device further comprises a flavour portion fluidly connected with the main airflow channel of the mouthpiece.

7. The aerosol-generating device according to claim 6, wherein the flavour portion is arranged in a tertiary airflow channel, wherein the tertiary airflow channel is fluidly connected with the secondary airflow channel.

8. The aerosol-generating device according to claim 7, wherein the aerosolgenerating device further comprises a flavour adjustment means, wherein the flavour adjustment means is configured to adjust the amount of airflow through the tertiary airflow channel by adjusting a minimum cross-sectional area of the tertiary airflow channel.

9. The aerosol-generating device according to any of claims 6 to 8, wherein the flavour portion comprises an adsorbent material impregnated with flavour.

10. The aerosol-generating device according to any of the preceding claims, wherein the secondary airflow channel is split into multiple airflow channels, preferably into 4 airflow channels.

11. The aerosol-generating device according to 10, wherein each airflow channel terminates into an air outlet for fluidly connecting the respective airflow channel with the main airflow channel.

12. The aerosol-generating device according to any of the preceding claims, wherein the multiple air outlets are uniformly distributed around the main airflow channel.

13. The aerosol-generating device according to any of the preceding claims, wherein the multiple air outlets are fluidly connected with a ring-shaped portion of the secondary airflow channel surrounding the main airflow channel.

14. An aerosol-generating system comprising the aerosol-generating device according to any of the preceding claims and an aerosol-generating article comprising aerosolforming substrate.

15. The aerosol-generating system according to claim 14, wherein the aerosolgenerating article is configured as a planar aerosol-generating article.

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