Aerosol-generating system with laminar air flow

Abstract

The invention relates to a device portion for an aerosol-generating system. The device portion (10) comprises an aerosol outlet channel (12) comprising an internal wall (14). The aerosol outlet channel extends between an aerosol inlet (16) and an aerosol outlet (18). The device portion (10) further comprises a side stream air inlet (20) and an air inlet channel (22) extending between the side stream air inlet (20) and an air outlet (24). The air outlet (24) is arranged in the aerosol outlet channel (12). The air outlet (18) is arranged to direct an at least partly laminar stream (26) of ambient air adjacent to the internal wall (14) of the aerosol outlet channel (12) such that the stream of ambient air (26) at least partly encloses an aerosol stream (28) flowing through the aerosol outlet channel (12). The invention further relates to an aerosol-generating system comprising the device portion and a mouthpiece for an aerosol-generating system comprising the device portion.

Description

[0001] AEROSOL-GENERATING SYSTEM WITH LAMINAR AIR FLOW

[0002] The present invention relates to a device portion for an aerosol-generating system. The present invention relates to an aerosol-generating system. The present invention relates to a mouthpiece for an aerosol-generating system.

[0003] It is known to provide an aerosol-generating system for generating an inhalable vapor. Such systems may heat aerosol-forming substrate to a temperature at which one or more components of the aerosol-forming substrate are volatilised without burning the aerosolforming substrate. An aerosol-forming substrate may be a liquid substrate contained in a reservoir. An aerosol-forming substrate may be a solid substrate 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 aerosolgenerating system. Such a chamber may be an aerosol generation chamber. A heater 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 system. The heating element may be part of the aerosol-generating system or may be part of the aerosol-generating article. In addition or alternatively, a cartridge comprising a liquid aerosol-forming substrate may be attached to or inserted into the aerosol-generating system for supplying the liquid aerosol-forming substrate to the device for aerosol generation in an aerosol generation chamber.

[0004] An airflow channel may run through the aerosol generation chamber. Ambient air may be drawn into the aerosol-generating system, into the aerosol generation chamber and towards the user through the airflow channel. Downstream of the aerosol generation chamber, a mouthpiece may be arranged. The airflow channel may extend through the mouthpiece. A portion of the airflow channel downstream to the aerosol generation chamber may be an aerosol outlet channel. The aerosol outlet channel may be upstream to the mouthpiece or run through the mouthpiece. The mouthpiece may be a permanent part of the aerosol-generating system or a reusable mouthpiece being separable from the aerosol-generating system. During usage of the aerosol-generating system aerosol may come in contact with internal walls of the aerosol-generation system, such as walls of the mouthpiece and / or aerosol outlet channel. After several usages of the aerosol-generating system, these internal walls may be contaminated with residuals from the aerosol. Internal walls of the mouthpiece and / or aerosol outlet channel may be stained. Cleaning may be required to remove such contaminations or stains. In addition, contact of the aerosol with the internal walls of the aerosol-generating system may result in the deposition of particles, particularly aerosol droplets, on the internal walls. Thereby aerosol may be lost or aerosol droplets may leak out of the aerosol-generating system which may negatively impair the user experience. It would be desirable to have an aerosol-generating system that reduces, preferably prevents, staining and / or droplet deposition of a mouthpiece of the aerosol-generating system. It would be desirable to have an aerosol-generating system that reduces, preferably minimizes, staining and / or droplet deposition of an airflow channel of the aerosol-generating system. It would be desirable to have an aerosol-generating system that reduces, preferably minimizes, staining and / or droplet deposition of an aerosol outlet channel of the aerosol-generating system. It would be desirable to have an aerosol-generating system that does not require cleaning of the mouthpiece. It would be desirable to protect an internal wall of a mouthpiece of an aerosol-generating system from aerosol. It would be desirable to protect an internal wall of an aerosol outlet channel of an aerosol-generating system from aerosol. It would be desirable to have an aerosol-generating system that reduces, preferably minimizes, condensation on internal walls of the aerosol-generating system. It would be desirable to have an aerosolgenerating system that reduces, preferably minimizes, loss of aerosol. It would be desirable to provide an aerosol-generating system that reduces, preferably minimizes, deposition of particles, in particular droplets, on internal walls of the aerosol-generating system.

[0005] According to an embodiment of the invention there is provided a mouthpiece for an aerosol-generating system. The mouthpiece may comprise one or more of a mouth-end portion comprising an aerosol outlet, an aerosol inlet, an aerosol channel extending between the aerosol inlet and the aerosol outlet, an air inlet, an air inlet channel extending between the air inlet and the aerosol channel. A downstream portion of the air inlet channel may be inclined with respect to the aerosol channel.

[0006] According to an embodiment of the invention there is provided a mouthpiece for an aerosol-generating system. The mouthpiece comprises a mouth-end portion comprising an aerosol outlet, an aerosol inlet, an aerosol channel extending between the aerosol inlet and the aerosol outlet, an air inlet, an air inlet channel extending between the air inlet and the aerosol channel. A downstream portion of the air inlet channel is inclined with respect to the aerosol channel. This may result in a laminar air flow.

[0007] By providing a mouthpiece comprising a downstream portion of an air inlet channel that is inclined with respect to an aerosol channel, an aerosol-generating system may be provided that reduces, preferably minimizes, the deposition of particles, in particular droplets, on internal walls during usage. By providing a mouthpiece comprising a downstream portion of an air inlet channel that is inclined with respect to an aerosol channel, an aerosol-generating system may be provided which reduces, preferably minimizes, the deposition of particles, in particular droplets, on internal walls during usage. By providing a mouthpiece comprising a downstream portion of an air inlet channel that is inclined with respect to an aerosol channel, a mouthpiece with an improved airflow design may be provided. The mouthpiece may comprise a longitudinal axis. The longitudinal axis of the mouthpiece may be parallel to a longitudinal axis of the aerosol-generating system. The longitudinal axis of the mouthpiece may extend between a proximal end of the mouthpiece and a distal end of the mouthpiece.

[0008] The aerosol channel may comprise a downstream portion and an upstream portion, and one turn between the upstream portion and the downstream portion. The aerosol channel may comprise only one turn. The downstream portion and the upstream portion may extend in different directions. The air inlet channel may join the aerosol channel in an area of the turn of the aerosol channel. The turn may be at least 45 degrees, preferably about 90 degrees. The upstream portion of the aerosol channel may be perpendicular to a longitudinal axis of the mouthpiece. The downstream portion of the aerosol channel may not be perpendicular to the longitudinal axis of the mouthpiece. The downstream portion of the aerosol channel may be parallel to the longitudinal axis of the mouthpiece. The aerosol-outlet may be arranged in an aerosol outlet plane. The aerosol outlet plane may be perpendicular to the longitudinal axis of the mouthpiece. The aerosol inlet may be arranged in an aerosol inlet plane. The aerosol inlet plane may be parallel to the longitudinal axis of the mouthpiece.

[0009] Alternatively, the aerosol channel may be straight and perpendicular to a longitudinal axis of the mouthpiece. In this embodiment the mouth-end portion may be arranged on a lateral side of the aerosol-generating device and the aerosol-generating system may be held vertically.

[0010] During usage of the aerosol-generating system, the air inlet channel may be configured to direct a wall of ambient air against the aerosol flow in the aerosol channel. The wall of ambient air may be configured to reduce, preferably prevent, a direct contact of the aerosol flow with the turn between the upstream portion and the downstream portion. During usage of the aerosol-generating system, the air inlet channel may be configured to direct a wall of ambient air against a wall of the aerosol channel. The wall of ambient air may reduce or prevent droplet deposition of the aerosol on internal walls of the aerosol-channel. The wall of ambient air may minimize collision and coalescence of the aerosol particles on internal walls of the aerosol-channel.

[0011] The downstream portion of the air inlet channel may comprise a longitudinal axis. The longitudinal axis of the downstream portion of the air inlet channel may not be parallel to the longitudinal axis of the mouthpiece. The longitudinal axis of the downstream portion of the air inlet channel may not be perpendicular to the longitudinal axis of the mouthpiece. The longitudinal axis of the downstream portion of the air inlet channel may enclose an angle of between 0 to 90 degrees with the longitudinal axis of the mouthpiece, preferably an angle of between 40 to 80 degrees. According to an embodiment of the invention there is provided a device portion for an aerosol-generating system. The device portion comprises an aerosol outlet channel comprising an internal wall. The aerosol outlet channel extends between an aerosol inlet and an aerosol outlet. The device portion further comprises a side stream air inlet and an air inlet channel extending between the side stream air inlet and an air outlet. The air outlet is arranged merging into the aerosol outlet channel. The air outlet is arranged to direct an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel such that the stream of ambient air at least partly encloses an aerosol stream flowing through the aerosol outlet channel.

[0012] According to an embodiment of the invention there is provided a device portion for an aerosol-generating system. The device portion may comprise an aerosol outlet channel comprising an internal wall. The aerosol outlet channel may extend between an aerosol inlet and an aerosol outlet. The device portion may comprise a side stream air inlet and an air inlet channel extending between the side stream air inlet and an air outlet. The air outlet may be arranged in the aerosol outlet channel. The air outlet may be arranged to direct an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel such that the stream of ambient air at least partly encloses an aerosol stream flowing through the aerosol outlet channel.

[0013] By directing an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel an aerosol-generating system may be provided that prevents or reduces staining of a mouthpiece of the aerosol-generating system. By directing an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel an aerosol-generating system may be provided that prevents or reduces staining of an airflow channel of the aerosol-generating system. By directing an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel an aerosol-generating system may be provided that prevents or reduces staining of the aerosol outlet channel of the aerosol-generating system. By directing an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel an aerosol outlet channel of an aerosol-generating system may be provided that does not require cleaning of a mouthpiece. By directing an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel an internal wall of a mouthpiece of an aerosol-generating system may be protected from aerosol. By directing an at least partly laminar stream of ambient air into an aerosol outlet channel an internal wall of the aerosol outlet channel of an aerosol-generating system may be protected from aerosol. By directing an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel an aerosol-generating system may be provided that prevents or reduces condensation on internal walls of the aerosol-generating system.

[0014] By directing an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel such that the stream of ambient air at least partly encloses an aerosol stream flowing through the aerosol outlet channel, contact of the aerosol stream with internal walls of the aerosol-generating system may be prevented. By directing an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel such that the stream of ambient air at least partly encloses an aerosol stream flowing through the aerosol outlet channel, mixing of the aerosol stream flowing through the aerosol outlet channel and the stream of ambient air may be prevented.

[0015] When referring to the ‘stream of ambient air’ the at least partly laminar stream of ambient air is referred to. When referring to the ‘stream of ambient air’ and the ‘aerosol stream flowing through the air outlet channel’, it is referred to streams being present during usage of the aerosol-generating system when a user draws on a mouthpiece of the aerosol-generating system.

[0016] The term ‘laminar’ refers to a stream that flows smooth with minimum to no turbulences.

[0017] As used herein, the term ‘aerosol-generating system’ is used to describe a system that interacts with an aerosol-forming substrate to generate an aerosol. Preferably, the aerosolgenerating system is a smoking system that interacts with an aerosol-forming substrate to generate an aerosol that is directly inhalable into a user’s lungs thorough the user's mouth.

[0018] The aerosol-generating system may comprise a longitudinal axis. The longitudinal axis may extend along the longitudinal extension of the aerosol-generating system. The longitudinal axis of the aerosol-generating system may extend between a proximal end of the aerosolgenerating system and a distal end of the aerosol-generating system.

[0019] As used herein, the term ‘proximal’ refers to a user-end, or mouth-end of the aerosolgenerating system or a part or portion thereof, and the term ‘distal’ refers to the end opposite to the proximal end. As used herein the term ‘lateral’ refers to a direction orthogonal to the longitudinal axis of the aerosol-generating system. A lateral cross section is a cross section in the lateral direction of the aerosol-generating system. A longitudinal cross section is a cross section along the longitudinal axis of the aerosol-generating system.

[0020] As used herein, the terms ‘upstream’, ‘downstream’, ‘proximal’ and ‘distal’ are used to describe the relative positions of components, or portions of components, of the aerosolgenerating system in relation to the direction in which a user draws on the aerosol-generating system during use thereof.

[0021] The aerosol-generating system may comprise a mouth-end through which in use an aerosol exits the aerosol-generating system 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 system in order to inhale an aerosol generated by the aerosolgenerating system. The aerosol-generating system comprises a distal end opposed to the proximal or mouth end. The proximal or mouth end of the aerosol-generating system may also be referred to as the downstream end and the distal end of the aerosol-generating system may also be referred to as the upstream end. Components, or portions of components, of the aerosol-generating system 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 system.

[0022] The aerosol inlet may be upstream of the aerosol outlet. The aerosol inlet may be arranged on a distal end of the aerosol outlet channel and the aerosol inlet may be arranged on a proximal end of the aerosol outlet channel. The air outlet may be arranged between the aerosol inlet and the aerosol outlet. The air outlet may be arranged to direct the stream of ambient air into the aerosol outlet channel. The air outlet may be arranged to direct the stream of ambient air along the internal wall of the aerosol outlet channel. The air outlet may be arranged to direct an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel such that a contact of the stream of ambient air with the internal wall of the aerosol outlet channel is reduced, preferably minimized, more preferably prevented.

[0023] The stream of ambient air may be partially laminar. The stream of ambient air adjacent the internal wall of the aerosol outlet channel may be laminar. The stream of ambient air may be fully laminar. The air outlet may be arranged to direct the stream of ambient air, and the aerosol inlet may be arranged to direct the aerosol stream flowing through the aerosol outlet channel, such that the stream of ambient air and the aerosol stream are in a laminar regime. The laminar regime may have a shear stress at an interface of the stream of ambient air and the aerosol stream flowing through the aerosol outlet channel that is minimized. The air outlet may be arranged to direct the stream of ambient air, and the aerosol inlet may be arranged to direct the aerosol stream flowing through the aerosol outlet channel, such that the streams do not mix.

[0024] A downstream portion of the air inlet channel may be inclined with respect to the aerosol outlet channel. The aerosol channel may comprise a downstream portion and an upstream portion, and one turn between the upstream portion and the downstream portion, preferably the aerosol outlet channel comprises only one turn. The air inlet channel may merge into the aerosol outlet channel in an aera of the turn of the aerosol channel. The turn may be at least 45 degrees, preferably about 90 degrees.

[0025] The stream of ambient air may partly enclose the aerosol stream flowing through the aerosol outlet channel. The stream of ambient air may fully enclose the aerosol stream flowing through the aerosol outlet channel. The air outlet may be arranged to direct the stream of ambient air such that the stream of ambient air partly or fully circumscribes the aerosol stream flowing through the aerosol outlet channel.

[0026] The air outlet may be arranged to direct the stream of ambient air parallel to the internal wall. The air outlet may be arranged to direct the stream of ambient air such that the stream of ambient air is parallel to the longitudinal axis of the aerosol-generating system. The aerosol outlet channel may be parallel to the longitudinal axis of the aerosol-generating system.

[0027] The air outlet may be arranged to direct the stream of ambient air such that the stream of ambient air flows in a lateral direction of the aerosol outlet channel between the internal wall and the aerosol stream flowing through the aerosol outlet channel.

[0028] The aerosol outlet channel may be configured to be arranged in an aerosol-generating system downstream of an aerosol generation chamber of the aerosol-generating system. The aerosol generation chamber may be a heating chamber configured for heating aerosol-forming substrate. The aerosol outlet channel may be configured to be arranged in an aerosolgenerating system downstream of a heating element in the aerosol-generating system.

[0029] Alternatively, the aerosol generation may be performed at ambient temperatures in the aerosol generation chamber. The aerosol may be generated in the aerosol generation chamber by mechanical action such as by a vibrating element such as a mesh or a membrane having a distribution of holes. Vibrating nebulizers use deformation or vibration of such a vibrating element to push a liquid therethrough.

[0030] The aerosol outlet may be a mouth-end though which in use an aerosol exits the aerosol-generating system and is delivered to a user. Alternatively, the aerosol outlet may be connected to an integral mouthpiece of the aerosol-generating system. The aerosol outlet reversibly connectable to a replaceable mouthpiece of the aerosol-generating system.

[0031] The aerosol stream flowing through the aerosol outlet channel may comprise at least two separate aerosol streams. The lateral cross sections of the at least two separate aerosol streams may be the same. The lateral cross sections of the at least two separate aerosol streams may be different.

[0032] The stream of ambient air may coaxially enclose the aerosol stream flowing through the aerosol outlet channel. A longitudinal central axis of the stream of ambient air and a longitudinal central axis of the aerosol stream flowing through the aerosol outlet channel may be the same.

[0033] The air outlet may be annular. The air outlet may have a tubular shape. The air outlet may be c-shaped. By providing a c-shaped air outlet the stream of ambient air may only partially enclose the aerosol stream flowing through the aerosol outlet channel. The stream of ambient air may be tubular. The tubular shape of the stream of ambient air may be provided by an annular or tubular air outlet.

[0034] A lateral cross section of the air outlet may be complementary to a lateral cross section of the aerosol inlet. An outer diameter of the lateral cross section of the aerosol inlet may be larger than an outer diameter of the cross section of the air outlet. An inner diameter of the lateral cross section of the aerosol inlet may be larger than the outer diameter of the cross section of the air outlet. Providing complementary lateral cross sections of the air outlet and the aerosol inlet may prevent mixing of the streams with each other.

[0035] The stream of ambient air may be convergent. The air outlet may be configured to direct a stream of ambient air that is converging towards to longitudinal axis of the aerosol outlet channel. A longitudinal axis of an end portion of the air inlet channel may be not parallel to the longitudinal axis of the aerosol outlet channel.

[0036] The aerosol stream flowing through the aerosol outlet channel may be cylindrical. The air outlet may be arranged to direct the stream of ambient air such that the stream of ambient air is tubular, and the aerosol inlet may be arranged to direct the aerosol stream flowing through the aerosol outlet channel such that the aerosol stream is cylindrical, preferably both may direct the streams such that the streams have matching shapes. Thereby mixing between the stream of ambient air and aerosol stream may be reduced, preferably minimized.

[0037] A longitudinal central axis of the stream of ambient air and a longitudinal central axis of the aerosol stream flowing through the aerosol outlet channel are parallel. Thereby the stream of ambient air and the aerosol stream flowing through the aerosol outlet channel may not be coaxially.

[0038] The aerosol outlet channel may comprise at least one ventilation air inlet configured to mix ambient air with vaporized aerosol-forming substrate. The at least one ventilation air inlet may either be arranged upstream of the air outlet, or downstream of the air outlet. Thereby the stream of aerosol entering the aerosol outlet channel may be cooled. Cooling the stream of aerosol may further enhance the aerosol generation. By arranging the at least one ventilation air inlet upstream of the air outlet channel turbulences of the aerosol stream enclosed by the stream of ambient air may be prevented. Thereby a laminar regime of the stream of ambient air and aerosol stream may be maintained.

[0039] The air inlet channel may comprise a turn. The turn may be a U-turn. Ambient air may enter the air inlet in a direction from the proximal end to the distal end of the aerosol-generating system. The ambient air may enter the aerosol outlet channel in a direction from the distal end to the proximal end of the aerosol-generating system.

[0040] A lateral cross section of the aerosol outlet channel may be circular or elliptical. The aerosol outlet channel may be convergent. The device portion may comprise a proximal portion and a distal portion. The air inlet channel may be confined between the proximal portion and the distal portion. The device portion may consist of the proximal portion and the distal portion. The distal portion may be arranged inserted into the proximal portion, or vice versa. A proximal end portion of the distal portion may have a smaller outer diameter than an inner diameter of a distal end of the proximal portion. The diameters of both the proximal end of the distal portion and the distal end of the proximal portion may be measured in a direction orthogonal to the longitudinal axis of the aerosol-generating system. The proximal end of the device portion may be a separable replaceable mouthpiece configured to be attached to the distal portion being part of a main body of an aerosol-generating system.

[0041] A ratio of a velocity of the ambient air flow to a velocity of the aerosol stream flowing through the aerosol outlet channel may be from 0.3 to 3, preferably from 0.5 to 2, more preferably about 1. Thereby mixing of the ambient air flow and the aerosol stream flowing through the aerosol outlet channel may be prevented or reduced. The ratio of the velocity of the ambient air flow to the velocity of the aerosol may be the ratio between the average velocity of the ambient air flow to the average velocity of the aerosol stream. Alternatively, the ratio of the velocity of the ambient air flow to the velocity of the aerosol stream may be the ratio between velocities of the ambient air flow and the aerosol stream at a boundary point between the ambient air flow and aerosol stream. The boundary point may be the first contact point between the ambient air flow and the aerosol stream.

[0042] According to an embodiment of the invention there is provided an aerosol-generating system comprising the device portion described herein. The aerosol-generating system may comprise a heating chamber for heating aerosol-forming substrate, a mouthpiece. The device portion may be arranged downstream of the heating chamber. The device portion may be arranged upstream of the mouthpiece, or integrated in the mouthpiece.

[0043] According to an embodiment of the invention there is provided a replaceable mouthpiece for an aerosol-generating system comprising the device portion described herein. The mouthpiece may be configured to be connected to a main body of an aerosol-generating system.

[0044] The aerosol-generating system may comprise a heating element. The heating element may be an inductive heating element. The heating element may comprise at least one inductor coil and the aerosol-generating article may comprise susceptor material. Alternatively, the susceptor material may be part of a susceptor element of the aerosol-generating system, preferably in or around a heating chamber. The inductor coil may be at least partly arranged around the heating chamber. Alternatively, the heating element may comprise an electrically resistive heating element. The heating element may comprise a heating blade. The heating blade may comprise one or more of a plurality of resistive tracks on an electrically insulating substrate. The heating blade may be mounted to the bottom wall of the heating chamber. The heating blade may be configured to be inserted into an aerosol-generating article. The main body of the aerosol-generating system may comprise the heating element.

[0045] As used herein, a ‘susceptor’ or ‘susceptor element’ means an element that heats up when subjected to an alternating magnetic field. This may be the result of eddy currents induced in the susceptor element, hysteresis losses, or both eddy currents and hysteresis losses. During use, the susceptor element is located in thermal contact or close thermal proximity with an aerosol-forming substrate received in the aerosol-generating article or cartridge. In this manner, the aerosol-forming substrate is heated by the susceptor such that an aerosol is formed.

[0046] The aerosol-forming substrate may comprise one or both of a solid aerosol-forming substrate and a liquid aerosol-forming substrate. The aerosol-forming substrate may comprise nicotine. The nicotine-containing aerosol-forming substrate may be a nicotine salt matrix.

[0047] The aerosol-forming substrate may comprise plant-based material. The aerosolforming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material including volatile tobacco flavour compounds which are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may comprise homogenised plant-based material. The aerosol-forming substrate may comprise homogenised tobacco material. Homogenised tobacco material may be formed by agglomerating particulate tobacco.

[0048] The aerosol-forming substrate may comprise at least one aerosol-former. An aerosolformer is any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol and that is substantially resistant to thermal degradation at the temperature of operation of the aerosol-generating system. Suitable aerosol-formers are well known in the art and include, but are not limited to: polyhydric alcohols, such as triethylene glycol, 1 ,3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1 ,3-butanediol. Preferably, the aerosol former is glycerine. Where present, the homogenised tobacco material may have an aerosol-former content of equal to or greater than 5 percent by weight on a dry weight basis, and preferably from 5 percent to 30 percent by weight on a dry weight basis. The aerosol-forming substrate may comprise other additives and ingredients, such as flavourants. The aerosol-generating system may comprise a housing. The housing may be formed from materials such as rigid plastic material (such as but not limited to polypropylene, high- density polyethylene (HDPE), polyethylene terephthalate (PET), polyetheretherketone (PEEK), or polysulfone (PSU)) or a metallic material (such as but not limited to aluminium). The main body of the aerosol-generating system may comprise the housing.

[0049] The housing may be elongate. The housing may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics or composite materials containing one or more of those materials, or thermoplastics that are suitable for food or pharmaceutical applications, for example polypropylene, polyetheretherketone (PEEK) and polyethylene. Preferably, the material is light and non-brittle. The housing may include a user interface to activate the aerosol-generating system, for example a button to initiate heating of the aerosol-generating system or a display to indicate a state of the aerosol-generating system or of the aerosol-forming substrate.

[0050] A wall of the housing of the aerosol-generating system may be provided with at least one main air inlet. The at least one main air inlet may be a semi-open inlet. The semi-open inlet may be an inlet which permits air or fluid flow in one direction, such as into the system, but at least restricts, preferably prohibits, air or fluid flow in the opposite direction. The semiopen inlet preferably allows air to enter the aerosol-generating system. Air or liquid may be prevented from leaving the aerosol-generating system through the semi-open inlet.

[0051] The aerosol-generating system may comprise electric circuitry. The main body of the aerosol-generating system may comprise the 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.

[0052] The aerosol-generating system may comprise a power supply, typically a battery, within a main body of the aerosol-generating system. The main body of the aerosol-generating system may comprise the power supply. 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-lron- 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.

[0053] Below, there is provided a non-exhaustive list of non-limiting examples.

[0054] Example Ex1. A device portion for an aerosol-generating system, comprising: an aerosol outlet channel comprising an internal wall, wherein the aerosol outlet channel extends between an aerosol inlet and an aerosol outlet; a side stream air inlet; and an air inlet channel extending between the side stream air inlet and an air outlet, wherein the air outlet is arranged merging into the aerosol outlet channel, wherein the air outlet is arranged to direct an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel such that the stream of ambient air at least partly encloses an aerosol stream flowing through the aerosol outlet channel.

[0055] Example Ex2. The device portion according to Ex1 , wherein the stream of ambient air adjacent the internal wall of the aerosol outlet channel is laminar.

[0056] Example Ex3. The device portion according to any of the preceding examples, wherein a downstream portion of the air inlet channel is inclined with respect to the aerosol channel.

[0057] Example Ex4. The device portion according to Ex3, wherein the aerosol channel comprises a downstream portion and an upstream portion, and one turn between the upstream portion and the downstream portion, preferably wherein the aerosol channel comprises only one turn.

[0058] Example Ex5. The device portion according to any of the preceding examples, wherein the air outlet is arranged to direct the stream of ambient air, and the aerosol inlet is arranged to direct the aerosol stream flowing through the aerosol outlet channel, such that the stream of ambient air and the aerosol stream are in a laminar regime.

[0059] Example Ex6. The device portion according to Ex5, wherein the laminar regime has a shear stress at an interface of the stream of ambient air and the aerosol stream flowing through the aerosol outlet channel that is minimized.

[0060] Example Ex7. The device portion according to any of the preceding examples, wherein the stream of ambient air fully encloses the aerosol stream flowing through the aerosol outlet channel. Example Ex8. The device portion according to any of the preceding examples, wherein the air outlet is arranged to direct the stream of ambient air parallel to the internal wall.

[0061] Example Ex9. The device portion according to any of the preceding examples, wherein the air outlet is arranged to direct the stream of ambient air such that the stream of ambient air flows in a lateral direction of the aerosol outlet channel between the internal wall and the aerosol stream flowing through the aerosol outlet channel.

[0062] Example Ex10. The device portion according to any of the preceding examples, wherein the aerosol outlet channel is configured to be arranged in an aerosol-generating system downstream of an aerosol generation chamber of the aerosol-generating system.

[0063] Example Ex11. The device portion according to example Ex. 10, wherein the aerosol generation chamber is a heating chamber configured for heating aerosol-forming substrate.

[0064] Example Ex12. The device portion according to any of the preceding examples, wherein the aerosol outlet channel is configured to be arranged in an aerosol-generating system downstream of a heating element in the aerosol-generating system.

[0065] Example Ex13. The device portion according to any of the preceding examples, wherein the aerosol outlet is a mouth-end through which in use an aerosol exits the aerosolgenerating system and is delivered to a user.

[0066] Example Ex14. The device portion according to any of the preceding examples, wherein the aerosol stream flowing through the aerosol outlet channel comprises at least two separate aerosol streams.

[0067] Example Ex15. The device portion according to any of the preceding examples, wherein the stream of ambient air coaxially encloses the aerosol stream flowing through the aerosol outlet channel.

[0068] Example Ex16. The device portion according to any of the preceding examples, wherein the air outlet is annular.

[0069] Example Ex17. The device portion according to any of the preceding examples, wherein the air outlet is c-shaped.

[0070] Example Ex18. The device portion according to any of the preceding examples, wherein the stream of ambient air is tubular.

[0071] Example Ex19. The device portion according to any of the preceding examples, wherein a lateral cross section of the air outlet is complementary to a lateral cross section of the aerosol inlet.

[0072] Example Ex20. The device portion according to any of the preceding examples, wherein the stream of ambient air is convergent. Example Ex21 . The device portion according to any of the preceding examples, wherein the aerosol stream flowing through the aerosol outlet channel is cylindrical.

[0073] Example Ex22. The device portion according to any of the preceding examples, wherein a longitudinal central axis of the stream of ambient air and a longitudinal central axis of the aerosol stream flowing through the aerosol outlet channel are parallel.

[0074] Example Ex23. The device portion according to any of the preceding examples, wherein the aerosol outlet channel comprises at least one ventilation air inlet configured to mix ambient air with vaporized aerosol-forming substrate, wherein the at least one ventilation air inlet is either arranged upstream of the air outlet, or downstream of the air outlet.

[0075] Example Ex24. The device portion according to any of the preceding examples, wherein the air inlet channel comprises a turn, preferably wherein the turn is a U-turn.

[0076] Example Ex25. The device portion according to any of the preceding examples, wherein the aerosol outlet channel has a lateral cross section that is circular or elliptical.

[0077] Example Ex26. The device portion according to any of the preceding examples, wherein the aerosol outlet channel is convergent.

[0078] Example Ex27. The device portion according to any of the preceding examples, comprising a proximal portion and a distal portion, wherein the air inlet channel is confined between the proximal portion and the distal portion.

[0079] Example Ex28. The device portion according to example Ex27, wherein the distal portion is arranged inserted into the proximal portion, or vice versa.

[0080] Example Ex29. The device portion according to any of the preceding examples, wherein a ratio of a velocity of the ambient air flow to a velocity of the aerosol stream flowing through the aerosol outlet channel is from 0.3 to 3, preferably from 0.5 to 2, more preferably about 1.

[0081] Example Ex30. An aerosol-generating system comprising the device portion according to any of the preceding examples, wherein the aerosol-generating system comprises a heating chamber for heating aerosol-forming substrate; a mouthpiece, wherein the device portion is arranged downstream of the heating chamber.

[0082] Example Ex31. The aerosol-generating system according to example Ex30, wherein the device portion is arranged upstream of the mouthpiece, or integrated in the mouthpiece.

[0083] Example Ex32. A replaceable mouthpiece for an aerosol-generating system comprising the device portion according to any of examples 1 to Ex 29, wherein the mouthpiece is a replaceable mouthpiece for an aerosol-generating system configured to be connected to a main body of an aerosol-generating system. Example Ex33. A mouthpiece for an aerosol-generating system, comprising: a mouth-end portion comprising an aerosol outlet; an aerosol inlet; an aerosol channel extending between the aerosol inlet and the aerosol outlet; an air inlet, an air inlet channel extending between the air inlet and the aerosol channel; wherein a downstream portion of the air inlet channel is inclined with respect to the aerosol channel.

[0084] Example Ex34. The mouthpiece according to example Ex33, wherein the aerosol channel comprises a downstream portion and an upstream portion, and one turn between the upstream portion and the downstream portion, preferably wherein the aerosol channel comprises only one turn.

[0085] Example Ex35. The mouthpiece according to example Ex34, wherein the air inlet channel joins the aerosol channel in an area of the turn of the aerosol channel.

[0086] Example Ex36. The mouthpiece according to any of examples Ex34 or Ex35, wherein the turn is at least 45 degrees, preferably about 90 degrees.

[0087] Example Ex37. The mouthpiece according to any of examples Ex34 to Ex36, wherein the upstream portion of the aerosol channel is perpendicular to a longitudinal axis of the mouthpiece.

[0088] Example Ex38. The mouthpiece according to example Ex37, wherein the downstream portion of the aerosol channel is not perpendicular to the longitudinal axis of the mouthpiece, preferably wherein the downstream portion of the aerosol channel is parallel to the longitudinal axis of the mouthpiece.

[0089] Example Ex39. The mouthpiece according to example Ex33, wherein the aerosol channel is straight and is perpendicular to a longitudinal axis of the mouthpiece.

[0090] Example Ex40. The mouthpiece according to any of examples Ex33 to Ex39, wherein during usage of the aerosol-generating system, the air inlet channel is configured to direct a wall of ambient air against an aerosol flow in aerosol channel.

[0091] Example Ex41 . The mouthpiece according to example Ex40, wherein the wall of ambient air is configured to reduce, preferably prevent, a direct contact of the aerosol flow with the turn of example Ex32.

[0092] Example Ex42. The mouthpiece according to any of examples Ex 33 to 41 , wherein during usage of the aerosol-generating system, the air inlet channel is configured to direct a wall of ambient air against a wall of the aerosol channel.

[0093] Example Ex43. The mouthpiece according to any of examples Ex 33 to 42, wherein the downstream portion of the air inlet channel comprises a longitudinal axis which encloses an angle of between 0 to 90 degrees with the longitudinal axis of the mouthpiece, preferably an angle of between 40 to 80 degrees.

[0094] Example Ex44. The mouthpiece according to any of examples Ex 33 to 43, wherein the aerosol inlet is configured connectable to an atomizer module of the aerosolgenerating system.

[0095] Example Ex45. The mouthpiece according to any of examples Ex 33 to 44, wherein an upstream portion of the air inlet channel is connected to a pressure sensor channel, wherein the pressure sensor channel is configured connectable to a main body of the aerosolgenerating system comprising a pressure sensor.

[0096] Example Ex46. The mouthpiece according to any of examples Ex 33 to 45, wherein the air inlet comprises a flow restriction.

[0097] Example Ex47. The mouthpiece according to any of examples Ex 33 to 46, wherein the aerosol channel has a cross-section having a circular or oval shape, or a shape of a rectangle with rounded corners.

[0098] Example Ex48. The mouthpiece according to any of examples Ex 33 to 47, comprising a proximal portion and a distal portion, wherein the proximal portion comprises the aerosol channel, and the distal portion comprises the air inlet channel.

[0099] Example Ex49. The mouthpiece according to any of examples Ex 33 to 48, wherein the air inlet is arranged at a distal end of the mouthpiece, preferably at a lateral side of the distal end.

[0100] Example Ex50. The mouthpiece according to any of examples Ex 33 to 49, wherein the air inlet channel has a cross-section having a non-circular shape.

[0101] Example Ex51 . The mouthpiece according to any of examples Ex 33 to 50, wherein the air inlet channel has a cross-section having an oval shape or a shape of a rectangle with rounded corners.

[0102] Example Ex52. An aerosol-generating system comprising: a main body; the replaceable mouthpiece according to example Ex32, or the mouthpiece according to any of examples Ex 33 to 51 , wherein the mouthpiece is a replaceable mouthpiece; an atomizer module; and a replaceable cartridge.

[0103] Example Ex53. The aerosol-generating system according to example Ex52, wherein, when the aerosol-generating system is assembled, the atomizer module is located in a lateral direction of the aerosol-generating system between the replaceable mouthpiece and the replaceable cartridge. Example Ex54. The aerosol-generating system according to any of examples Ex52 or Ex53, wherein the replaceable cartridge is reversibly insertable from a lateral side of the aerosol-generating system.

[0104] Example Ex55. The aerosol-generating system according to any of examples Ex52 to Ex54, wherein the atomizer module comprises a piezo-electric actuator.

[0105] Example Ex56. The aerosol-generating system according to any of examples Ex52 to Ex55, wherein the atomizer module comprises a vibrating element.

[0106] Example Ex57. The aerosol-generating system according to example Ex56, wherein the vibrating element is one of a vibrating mesh, a vibrating membrane, or a vibrating plate.

[0107] Example Ex58. The aerosol-generating system according to any of examples Ex56 or Ex57, wherein the vibrating element is disposed on a vibrating plane, wherein, when the aerosol-generating system is assembled, the vibrating plane is not perpendicular to a longitudinal axis of the aerosol-generating system, preferably wherein the vibrating plane is parallel to or includes the longitudinal axis of the aerosol-generating system.

[0108] Example Ex59. The aerosol-generating system according to any of examples Ex56 to Ex58, wherein the vibrating element is flat shaped, preferably disc shaped.

[0109] Example Ex60. The aerosol-generating system according to any of examples Ex52 to Ex59, wherein the aerosol-generating system does not comprise a heating element.

[0110] Example Ex61 . The aerosol-generating system according to any of examples Ex52 to Ex60, wherein, when the aerosol-generating system is assembled, the aerosolgenerating system provides a liquid flow from the replaceable cartridge to the atomizer module in a direction perpendicular to the longitudinal axis of the aerosol-generating system.

[0111] Example Ex62. The aerosol-generating system according to any of examples Ex52 to Ex61 , wherein, when the aerosol-generating system is assembled, the main body is in direct contact with the atomizer module and with the replaceable mouthpiece.

[0112] Example Ex63. The aerosol-generating system according to any of examples Ex52 to Ex62, wherein, when the aerosol-generating system is assembled, the replaceable cartridge is not in direct contact with the main body.

[0113] Example Ex64. The aerosol-generating system according to any of examples Ex52 to Ex63, wherein the atomizer module is L-shaped.

[0114] Example Ex65. The aerosol-generating system according to any of examples Ex52 to Ex64, wherein the atomizer module comprises at a distal end a laterally protruding portion comprising a locking system configured lockingly connectable to the replaceable cartridge. Example Ex66. The aerosol-generating system according to any of examples Ex52 to Ex65, wherein the replaceable cartridge is configured reversibly connectable to the atomizer module.

[0115] Example Ex67. The aerosol-generating system according to example Ex66, wherein the replaceable cartridge is reversibly connectable to the atomizer module via at least one of a hinge mechanism, a sliders mechanism, a snap-fit mechanism, a bayonet mechanism, a magnetic mechanism, a spring actuated mechanism, or a push-push mechanism.

[0116] Example Ex68. The aerosol-generating system according to example Ex67, wherein the replaceable cartridge is reversible connectable to the atomizer module via a hinge mechanism, and the replaceable cartridge comprises a hinge protrusion and the atomizer module comprises a receiving part configured for receiving the hinge protrusion of the replaceable cartridge.

[0117] Example Ex69. The aerosol-generating system according to example Ex69, wherein the replaceable cartridge comprises the hinge protrusion at a proximal end, and the atomizer module comprises the receiving part at a proximal end.

[0118] Example Ex70. The aerosol-generating system according to any of examples Ex52 to Ex69, wherein the atomizer module is configured connectable to the main body, preferably wherein the atomizer module is replaceable and configured reversibly connectable to the main body.

[0119] Example Ex71. The aerosol-generating system according to any of examples Ex52 to Ex 70, wherein the replaceable mouthpiece is configured reversibly connectable to the atomizer module.

[0120] Example Ex72. The aerosol-generating system according to example Ex71 , wherein the replaceable mouthpiece is reversibly connectable to the atomizer module via at least one of a hinge mechanism, a sliders mechanism, a snap-fit mechanism, a bayonet mechanism, a magnetic mechanism, a spring actuated mechanism, or a push-push mechanism.

[0121] Example Ex73. The aerosol-generating system according to any of examples Ex52 to Ex72, wherein the replaceable cartridge comprises a liquid storage portion configured for storing liquid aerosol-forming substrate.

[0122] Example Ex74. The aerosol-generating system according to example Ex73, wherein the replaceable cartridge comprises a fluid permeable element being in fluid communication with the liquid storage portion.

[0123] Example Ex75. The aerosol-generating system according to example Ex74, wherein the fluid permeable element has a cylindrical shape, preferably wherein the fluid permeable element is cylindrical. Example Ex76. The aerosol-generating system according to any of example Ex74 or Ex75, wherein the fluid permeable element comprises or consists of a porous material, preferably wherein the fluid permeable element comprises or consists of a porous wicking material.

[0124] Example Ex77. The aerosol-generating system according to any of examples Ex74 to Ex76, wherein the fluid permeable element is arranged on a lateral side of the replaceable cartridge, preferably wherein a portion of the fluid permeable element is protruding from an outer surface of the replaceable cartridge.

[0125] Example Ex78. The aerosol-generating system according to example Ex77, wherein the protruding portion comprises an end surface, wherein, when the aerosolgenerating system is assembled, the end surface is located parallel to the vibrating element of example Ex56.

[0126] Example Ex79. The aerosol-generating system according to any of examples Ex74 to Ex78, wherein, when the aerosol-generating system is assembled, the fluid permeable element faces the vibrating element of example Ex56, preferably wherein the fluid permeable element is in fluid communication with the vibrating element of example Ex56.

[0127] Example Ex80. The aerosol-generating system according to any of examples Ex74 to Ex79, wherein when the aerosol-generating system is assembled, there is a gap between the fluid permeable element and the vibrating element, preferably wherein the gap is of between 0.01 millimeter to 0.5 millimeter, more preferably between 0.02 millimeter to 0.2millimeter.

[0128] Example Ex81 . The aerosol-generating system according to any of examples Ex52 to Ex80, wherein the atomizer module comprises electrical connection means configured to be electrically connected to the main body.

[0129] Example Ex82. The aerosol-generating system according to any of examples Ex52 to Ex781 , wherein the main body comprises at least one of a power supply, control electronics and a pressure sensor.

[0130] Example Ex83. A method for assembling the aerosol-generating system according to any of examples Ex 52 to Ex82, comprising reversibly connecting the atomizer module to the main body, reversibly connecting the replaceable mouthpiece to the atomizer module, reversibly connecting the replaceable cartridge to the atomizer module from a lateral side of the aerosol-generating system.

[0131] Example Ex84. The method according to example Ex83, wherein the replaceable mouthpiece is connected to the atomizer module by an insertion from a lateral side of the aerosol-generating system, followed by a sliding movement in a longitudinal direction towards the main body.

[0132] Example Ex85. The method according to any of examples Ex83 or Ex84, wherein the replaceable cartridge is connected to the atomizer module via a hinge mechanism.

[0133] Features described in relation to one embodiment may equally be applied to other embodiments of the invention.

[0134] 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.

[0135] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0136] Figs. 1A and 1 B show longitudinal cross sections of device portions for aerosolgenerating systems;

[0137] Figs. 2A, 2B and 2C show streams of ambient air and aerosol streams for an aerosolgenerating system;

[0138] Figs. 3A, 3B and 3C show lateral cross sections of streams of ambient air and aerosol streams;

[0139] Figs. 4A, 4B and 4C show further embodiments of device portions for an aerosolgenerating system;

[0140] Fig. 5A shows the aerosol-generation and airflow of the aerosol-generating system; Figs 5B and 5C show the design of the mouthpiece;

[0141] Fig. 6 shows an aerosol-generating system.

[0142] Fig. 1A shows a device portion 10 for an aerosol-generating system (not completely shown). The aerosol-generating system comprises additional components like a power supply and a controller (not shown). The device portion 10 comprises an aerosol outlet channel 12 comprising an internal wall 14. The aerosol outlet channel extends between an aerosol inlet 16 and an aerosol outlet 18. The aerosol outlet 18 is at a proximal end of the aerosol outlet channel and the aerosol inlet 16 is at a distal end of the aerosol outlet channel 12. The device portion 10 further comprises a side stream air inlet 20, and an air inlet channel 22 extending between the side stream air inlet 20 and an air outlet 24. The air inlet channel has a U-turn. The air outlet 24 22 is arranged merging into the aerosol outlet channel 12. The air outlet 24 22 is arranged to direct an at least partly laminar stream 26 of ambient air adjacent to the internal wall 14 such that the stream of ambient air 26 at least partly encloses an aerosol stream 28 flowing through the aerosol outlet channel 12.

[0143] The aerosol stream 24 is generated by heating an aerosol-forming substrate 30 received in a cavity 34 of the aerosol-generating system. The cavity may also be referred to as aerosol generation chamber or heating chamber. In the embodiment shown in Figs. 1 A and 1 B the aerosol-forming substrate is heated by an internal heating element 32. The heating element can be a susceptor portion contained in the aerosol-forming substrate 30 and heated by an induction coil of the aerosol-generating system (not shown). Alternatively, the heating element can be a permanent part of the aerosol-generating system. For example, the heating element can be comprised in the cavity of the aerosol-generating system as a heating blade being part of the aerosol-generating system. The heating element can then either be a susceptor heating element or a resistive heating element.

[0144] The device portion 26 can be a permanent part of an aerosol-generating system. The aerosol outlet 18 can be a mouth-end whereby the device portion 26 is a mouthpiece of an aerosol-generating system. Such a device portion 26 being a mouthpiece can either be a separable replaceable mouthpiece or a permanent part of an aerosol-generating system. A replaceable mouthpiece may be reusable. Alternatively or additionally, an additional permanent or separable replaceable mouthpiece (not shown) may be added to the proximal end of the device portion 26.

[0145] Fig. 1 B shows a device portion 10’ comprising the same components as the device portion 10 and having the same configurations except that an air outlet 24’ 22 is arranged to direct an at least partly laminar stream of ambient air 26’ adjacent to the internal wall 14 such that the stream of ambient air 26’ at least partly encloses an aerosol stream (not shown) flowing through the aerosol outlet channel 12 and such that the stream of ambient air 26’ is convergent.

[0146] Figs. 2A and 2B show schematically the flow of the stream of ambient air 26 and the aerosol stream in an aerosol outlet 12 channel of the device portion 10. Fig. 2A shows a 3D view and a longitudinal cross section of the stream of ambient air 26 fully enclosing the aerosol stream 28. Thereby a direct contact of the aerosol stream 28 with the internal wall 14 (not shown) of the aerosol outlet channel 12 is prevented. Fig. 2B shows a schematically flow of the stream of ambient air 26 and the aerosol stream 28. The stream of ambient air 26 and the aerosol stream 28 do not mix with each other. The stream of ambient air 26 and the aerosol stream 28 are in a laminar regime. The stream of ambient air 26 and the aerosol stream 28 have minimum shear stress at the interface 36 of the two streams. Thereby turbulences are prevented.

[0147] Fig 2C shows a stream of ambient air 26 and an aerosol stream 26. The differences between a), b) and c) is that the streams flow with different velocities. In Fig. 2C a) a velocity of the flow of ambient air 28 and a velocity of the aerosol flow 26 are the same whereby a ratio between the velocity of the flow of ambient air 28 and the velocity of the aerosol flow 26 is 1. In Fig. 2C b) the flow of ambient air 26 has a higher velocity than the velocity of the aerosol flow 28 and a ratio between the velocity of the flow of ambient air 28 and the velocity of the aerosol flow 26 is 2. It can be seen that there is no sharp boarder between the two streams and the two streams to some extend mix which each other. In Fig. 2C c) the flow of ambient air 26 has an even higher velocity than in Fig. 2C b) and a ratio between the velocity of the flow of ambient air 28 and the velocity of the aerosol flow 26 is 2.8. It can be seen that the boarded between the two streams blurs even further than in Fig. 2C b) and the two streams to some extend mix which each other.

[0148] Figs. 3A, 3B and 3C show lateral cross sections of streams of ambient air and aerosol. Contrary to the streams as shown in the previous figures, Fig. 3A shows a stream of ambient air 38 not coaxially enclosing an aerosol stream 40. The longitudinal axes of the streams extending orthogonal to the cross section are parallel but not identical. Fig 3B shows a stream of ambient air 42 enclosing an aerosol stream comprising two separate aerosol streams 44 and 46. Fig. 3C shows a stream of ambient air 48 partially enclosing a stream of aerosol 50. The specific lateral cross sections of the streams of ambient air 38, 42 and 48 are provided by corresponding shapes of aerosol outlets of the aerosol inlet channel (not shown). The specific lateral cross sections of the streams of aerosol 40, 44, 46, and 50 are provided by corresponding shapes of aerosol inlets of the aerosol outlet channel. The shapes of the lateral cross sections of the aerosol outlets of the aerosol inlet channel and the aerosol inlets of the aerosol outlet channel can have complementary shapes.

[0149] Figs. 4A, 4B and 4C show longitudinal cross sections of further embodiments of a device portion 10” for an aerosol-generating system. The device portion 10” comprises the same components as discussed in context of the device portion 10. The device portion 10” can also comprise the same alternative components of the device portion 10’. The difference from the device portion 10” to the device portions 10 and 10’ is that the device portion 10” comprises at least one additional ventilation air inlet 52. Thereby a cooling of the aerosol generated in the upstream aerosol generation chamber is provided.

[0150] In addition, it can also be seen in Fig. 4A that the device portion 10” comprises a proximal portion 54 and a distal portion 56. The air inlet channel 22 is confined between the proximal portion 54 and the distal portion 56. The distal portion 56 is arranged inserted into the proximal portion 54. The proximal portion 54 can be a separable mouthpiece which is configured reversable connectable to the distal portion 56 which is part of a main body of an aerosol-generating system. The device portions 10 and 10’ can comprise the proximal portion 54 and the distal portion 56 as described for the device portion 10” as well.

[0151] Figs. 4B and 4C show different locations of the at least one ventilation air inlets 52’ and 52”. Figs. 4B and 4C only schematically show the air inlet channel 22 directing a stream of ambient air 28 into an aerosol outlet channel 12. In Fig. 4B the at least one ventilation air inlets 52’ are arranged upstream of the air outlet 22. In Fig. 4C the at least one ventilation air inlets 52” are arranged downstream of the air outlet 22. Fig. 5A shows the aerosol generation during usage of an aerosol-generating system 100, schematically shown in Figure 5A. The aerosol-generating system 100 comprises a main body 120 a replaceable mouthpiece 140, an atomizer module 160, a cartridge 180. Liquid aerosol forming substrate flows from a liquid storage portion 500 of the cartridge 180 through the openings of a retainer 480 towards and through a fluid permeable element 460 illustrated by arrows 620. The liquid aerosol-forming substrate then flows from an end surface 640 of the fluid permeable element 460 towards a vibrating membrane 600 where an aerosol is generated in an aerosol-generation zone, the aerosol flow is illustrated by arrows 660. As can be seen in Fig. 5A, in an assembled state of the aerosol-generating system 100, the vibrating membrane 600 of the atomizer module 160 is arranged parallel to a longitudinal axis 200 of the aerosolgenerating system 100. Preferably a small gap is provided between the vibrating membrane 600 and the end surface 640 of the fluid permeable element of the cartridge 180. The gap may be of between 0.01 millimeter to 0.5 millimeter, preferably between 0.02 millimeter to 0.2 millimeter.

[0152] The replaceable mouthpiece 140 comprise a mouth-end portion comprising an aerosol outlet 680, an aerosol inlet 700 (see Fig 5B), an aerosol channel 720 (see Fig. 5C) extending between the aerosol inlet 700 and the aerosol outlet 680, an air inlet 740 (see Fig 5C), an air inlet channel 760 extending between the air inlet 740 and the aerosol channel 720. A downstream portion 780 of the air inlet channel 760 is inclined with respect to the aerosol channel 720. A laminar airflow may thereby be provided.

[0153] The downstream portion 780 of the air inlet channel 760 comprises a longitudinal axis 800. The longitudinal axis 800 of the downstream portion 780 of the air inlet channel 760 encloses an angle 820 with the longitudinal axis of the aerosol-generating system 220 which is parallel to the longitudinal axis of the replaceable mouthpiece (not shown). The angle 820 is between 0 to 90 degrees, preferably between 40 to 80 degrees.

[0154] During usage of the aerosol-generating system 100, the air inlet channel 760 directs a wall 840 of ambient air, shown by the arrows 86, against the aerosol flow 660 in the aerosol channel 720.

[0155] The aerosol inlet 700 is axially circumscribed by a replaceable mouthpiece sealing member 900 provide an air- and / or liquid-tight sealing with the atomizer module 160.

[0156] The air inlet channel 760 may be connected to a pressure sensor channel 920. The pressure sensor channel 920 is configured connectable to the main body 120 comprising a pressure sensor 940.

[0157] Fig. 6 shows an outer view of the aerosol-generating system 100. It will be appreciated that in an embodiment the aerosol-generating system comprises the main body 120, the replaceable mouthpiece 140, the atomizer module 160 and the replaceable cartridge 180. The atomizer module 160 may be located in a lateral direction 200 of the aerosol-generating system 100 between the replaceable mouthpiece 140 and the replaceable cartridge 180. The lateral direction or axis 200 may be perpendicular to the longitudinal axis 220 of the aerosolgenerating system 100. The atomizer module 160 is sandwiched between the replaceable mouthpiece 140 and the replaceable cartridge 180. The replaceable cartridge 180 is directly connected to the atomizer module 160, but not to the main body 120, due to the L-shape of the atomizer module 160.

[0158] A connection mechanism may be provided for the replaceable cartridge 180 to the atomizer module 160. The replaceable cartridge 180 may comprise a hinge protrusion on a proximal end of the replaceable cartridge. The hinge protrusion may be configured to be hooked onto to a rod of the atomizer module 160. The distal end of the atomizer module 160 may comprise at a laterally protruding portion a locking system comprising a sliding portion. The sliding portion may be configured lockingly connectable to the hinge protrusion. The replaceable cartridge 180 may comprise a receiving portion for receiving the sliding portion of the atomizer module 160.

[0159] After hooking the hinge protrusion onto the rod the replaceable cartridge 180 can be rotated downward towards the distal end of the atomizer module 160. Afterwards the replaceable cartridge 180 can be lockingly engaged to the atomizer 160 module via the sliding portion being received within the receiving portion of the replaceable cartridge 180 resulting in the assembled state of the aerosol-generating system. To remove the replaceable cartridge 180 from the atomizer module 160, the sliding portion needs to be pushed down along the longitudinal axis 220 of the aerosol-generating system 100.

[0160] The replaceable mouthpiece 140 may be connected to the atomizer module 160 by an insertion from a lateral side of the aerosol-generating system 100, followed by a sliding movement in a longitudinal direction towards the main body 120.

[0161] The replaceable mouthpiece 140 may comprises a proximal recess at a proximal end of the replaceable mouthpiece and two distal recesses and at a distal end of the replaceable mouthpiece 140. The atomizer module 160 may comprise a proximal protruding connection portion and two distal protruding connection portions. The proximal recess of the replaceable mouthpiece 140 is configured to receive the proximal protruding connection portion of the atomizer module 180 and the distal recesses are configured to receive the distal protrusions of the atomizer module 160, respectively. The recesses of the replaceable mouthpiece 140 are shaped to provide a slidable insertion with the protruding connection portion of the atomizer module 160.

[0162] The fluid permeable element 460 may be a cylindrical porous wick. A protruding portion protrudes from a lateral outer surface of the replaceable cartridge 180. The protruding portion may protrude from the lateral outer surface of between 0.05 millimeters to 5 millimeters, preferably between 0.3 millimeters to 2 millimeters.

[0163] A vibratable transducer holder may be provided comprising a washer shaped vibratable transducer which holds a vibrating membrane 600. The vibratable transducer holder may be overmoulded around the vibratable transducer. The vibratable transducer is preferably a piezoelectric actuator. The vibratable transducer holder comprises electrical connections configured connectable to the power supply of the main body (not shown).

[0164] When the aerosol-generating system 100 is assembled, an end surface 640 of the fluid permeable element 460 is located parallel to the vibrating element 600. When the aerosol- generating system 100 is assembled, and the fluid permeable element 460 faces the vibrating element 600 of the atomizer module 16. In an assembled state, the fluid permeable element 460 and the vibrating element 600 are in fluid communication to each other.

Claims

CLAIMS1 . A device portion for an aerosol-generating system, comprising: an aerosol outlet channel comprising an internal wall, wherein the aerosol outlet channel extends between an aerosol inlet and an aerosol outlet; a side stream air inlet; and an air inlet channel extending between the side stream air inlet and an air outlet, wherein the air outlet is arranged merging into the aerosol outlet channel, wherein the air outlet is arranged to direct an at least partly laminar stream of ambient air adjacent to the internal wall of the aerosol outlet channel such that the stream of ambient air at least partly encloses an aerosol stream flowing through the aerosol outlet channel.

2. The device portion according to claim 1 , wherein the stream of ambient air adjacent the internal wall of the aerosol outlet channel is laminar.

3. The device portion according to claim 1 or 2, wherein a downstream portion of the air inlet channel is inclined with respect to the aerosol outlet channel.

4. The device portion according to claim 3, wherein the aerosol outlet channel comprises a downstream portion and an upstream portion, and one turn between the upstream portion and the downstream portion, preferably wherein the aerosol outlet channel comprises only one turn.

5. The device portion according to any of the preceding claims, wherein the air outlet is arranged to direct the stream of ambient air, and the aerosol inlet is arranged to direct the aerosol stream flowing through the aerosol outlet channel, such that the stream of ambient air and the aerosol stream are in a laminar regime.

6. The device portion according to any of the preceding claims, wherein the air outlet is arranged to direct the stream of ambient air parallel to the internal wall.

7. The device portion according to any of the preceding claims, wherein the aerosol outlet channel is configured to be arranged in an aerosol-generating system downstream of an aerosol generation chamber of the aerosol-generating system.

8. The device portion according to claim 7, wherein the aerosol generation chamber is a heating chamber configured for heating aerosol-forming substrate.

9. The device portion according to any of the preceding claims, wherein the aerosol outlet channel is configured to be arranged in an aerosol-generating system downstream of a heating element in the aerosol-generating system.

10. The device portion according to any of the preceding claims, wherein the aerosol stream flowing through the aerosol outlet channel comprises at least two separate aerosol streams.11 . The device portion according to any of the preceding claims, wherein the stream of ambient air coaxially encloses the aerosol stream flowing through the aerosol outlet channel.

12. The device portion according to any of the preceding claims, wherein a ratio of a velocity of the ambient air flow to a velocity of the aerosol stream flowing through the aerosol outlet channel is from 0.3 to 3, preferably from 0.5 to 2, more preferably about 1.

13. An aerosol-generating system comprising the device portion according to any of the preceding claims, wherein the aerosol-generating system comprises a heating chamber for heating aerosol-forming substrate; a mouthpiece, wherein the device portion is arranged downstream of the heating chamber.

14. The aerosol-generating system according to claim 13, wherein the device portion is arranged upstream of the mouthpiece, or integrated in the mouthpiece.

15. A replaceable mouthpiece for an aerosol-generating system comprising the device portion according to any of claims 1 to 12, wherein the mouthpiece is a replaceable mouthpiece for an aerosol-generating system configured to be connected to a main body of an aerosol-generating system.

Images