Aerosol generating system with a venturi element

Abstract

To provide an aerosol-generating system comprising an aerosol-forming substrate and a venturi element.SOLUTION: An aerosol-generating system includes an aerosol forming substrate and a venturi element. The venturi element includes an airflow channel. The airflow channel includes an inlet portion, a central portion, and an outlet portion. The inlet portion is configured to converge toward the central portion, the outlet portion is configured to diverge from the central portion, and the inlet portion is configured to converge, at an inlet angle of 1 to 20 degrees, toward the central portion, and the outlet portion diverges from the central portion at an exit angle of 2 to 10 degrees.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an aerosol generating system and a kit of venturi elements. [Background technology]

[0002] It is known to provide an aerosol-generating device for generating an inhalable vapour. Such a device is capable of heating an aerosol-forming substrate to a temperature at which one or more components of the aerosol-forming substrate volatilise without combusting the aerosol-forming substrate. Such an aerosol-forming substrate may be provided as part of an aerosol-generating article.

[0003] Such an aerosol-generating article may comprise many components. For example, it is known to provide an aerosol-generating article comprising a substrate portion, a filter portion, a cooling portion, and a spacer portion. The cooling portion may comprise a crimped sheet of material such as polylactic acid (PLA). The spacer portion may comprise a hollow tube such as a hollow acetate tube. The spacer portion may provide the aerosol-generating article with improved structural stability, which may contribute to improved aerosol generation. The cooling portion may contribute to improved aerosol generation.

[0004] Such an aerosol-generating device may be arranged to receive an aerosol-generating article comprising an aerosol-forming substrate. The aerosol-generating article may have a rod shape for inserting 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 when the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device. Typically, one or more components of the aerosol-forming substrate are vaporized by the heating element and entrained in air to form an aerosol. The formation of the aerosol, particularly the size of the droplets, depends on several factors, such as temperature, air pressure, etc.

[0005] It is desirable to provide an aerosol generating system with improved aerosol generation. It is desirable to provide an aerosol generating system that facilitates customization of the aerosol that can be generated. It is desirable to provide an aerosol generating system with improved aerosol generation for different aerosol-forming substrates. It is desirable to provide an aerosol generating system with improved RTD. It is desirable to provide an aerosol generating system with improved mouthfeel. It is desirable to provide an aerosol generating system with improved flavor delivery. It is desirable to provide an aerosol generating article with fewer components. Summary of the Invention

[0006] According to a first aspect of the present invention, there is provided an aerosol generating system comprising an aerosol-forming substrate and a venturi element.

[0007] Cost-effective manufacturing is one advantage of providing a Venturi element in an aerosol generation system. By providing a Venturi element in an aerosol generation system, a separate cooling section such as crimped PLA or hollow acetate tubing (HAT) may not be required for aerosol generation.

[0008] The aerosol-generating system may comprise an aerosol-generating article. The aerosol-generating article may comprise an aerosol-forming substrate. The aerosol-generating article may comprise a Venturi element. The Venturi element may be part of the aerosol-generating article, preferably an integral part of the aerosol-generating article, more preferably integrally formed therewith. The Venturi element may be permanently attachable to the aerosol-generating article.

[0009] It may be unnecessary for the user to assemble the system, in particular to attach the Venturi element to the aerosol-generating article. Simplicity or ease of use may be an advantage of an aerosol-generating article including a Venturi element. Another advantage may be the simplification of manufacture of a Venturi element that is an integral part of the aerosol-generating article, due to the fact that the Venturi element may be formed together with the aerosol-forming substrate during manufacture of the aerosol-generating article. A consistent smoking experience may be a further advantage of this embodiment, as correct alignment of the Venturi element during manufacture with the aerosol-forming substrate included within the aerosol-generating article is ensured.

[0010] The term "part of", preferably "an integral part of", and more preferably "integrally formed with", may refer to a configuration in which the aerosol-generating article and the Venturi element are configured as a single piece. In other words, the Venturi element and the aerosol-generating article are not separable.

[0011] In some embodiments, the Venturi element may be configured to be attachable to the aerosol-generating article. Preferably, the Venturi element may be configured to be removably attachable to the aerosol-generating article.

[0012] Interchangeability is an advantage of the removably attachable configuration of the Venturi element. The Venturi element may be compatible for different delivery profiles, different smoking experiences, and different aerosol vaporization. The different delivery profiles, different smoking experiences, and different aerosol vaporization may be referred to as usage experiences below. Customization may be preferred by users, as they may be able to adapt the usage experience to their own personal preferences. Users may change the Venturi element to be attached depending on the desired usage experience. According to this aspect, the Venturi element may be reusable, which may reduce waste.

[0013] The attachment between the Venturi element and the aerosol-generating article is described in more detail below. The attachment described below is preferably facilitated in an embodiment in which the Venturi element is removably attachable to the aerosol-generating article. However, the attachment described below may also be utilized in an embodiment in which the attachment is permanent, such that the Venturi element is an integral part of the aerosol-generating article.

[0014] The aerosol-generating article may include a connecting portion. The Venturi element may include an airflow channel including an inlet portion. The Venturi element may include a connecting element. The inlet portion may include a connecting element. Alternatively, the connecting element may be disposed adjacent to the inlet portion. The connecting portion of the aerosol-generating article may be configured to removably receive the connecting element of the Venturi element.

[0015] In some embodiments, the connecting portion of the aerosol-generating article may be configured as a filter portion, in particular a hollow acetate tube.

[0016] Alternatively, the connecting portion may be made of any desired material that allows the connecting element of the Venturi element to be removably received within the connecting portion. The connecting element of the Venturi element may be an integral part of the Venturi element. The connecting element is preferably disposed at the upstream end of the Venturi element. The connecting element may be an integral part of the inlet portion or disposed immediately adjacent to the inlet portion. The connecting element may be made of a solid material that allows the penetration of the connecting portion of the aerosol-generating article. The connecting element may be configured to penetrate the connecting portion of the aerosol-generating article. The connecting element of the Venturi element may include an airflow channel, preferably a hollow central airflow channel. The connecting element of the Venturi element may have a tapered configuration towards the upstream end of the connecting element to simplify the insertion of the connecting element into the connecting portion of the aerosol-generating article. The Venturi element may then be disposed directly against the aerosol-generating article, more specifically the connecting portion of the aerosol-generating article. The connecting portion of the aerosol-generating article may have a substantially tubular shape. The connecting part of the aerosol-generating article may have a hollow tubular shape such that the connecting element of the Venturi element can be inserted into the hollow tubular connecting part. The inner wall of the hollow tubular connecting part of the aerosol-generating article may include a mechanical retaining means configured to retain the connecting element of the Venturi element inside the connecting part of the aerosol-generating article. The Venturi element may be provided as a reusable element for use with multiple aerosol-generating articles. After the aerosol-generating article is consumed, the Venturi element can be removed from the article and connected to a new article. For example, the Venturi element may be provided with a pack of aerosol-generating articles such that the Venturi element can be used for all aerosol-generating articles contained in the pack. Thus, costs may be saved by providing a single Venturi element for multiple aerosol-generating articles.

[0017] The connecting element of the Venturi element may include a mechanical retention means configured to hold the connecting element of the Venturi element within the connecting portion of the aerosol-generating article. The mechanical retention means may be configured to permanently attach the Venturi element to the aerosol-generating article. The mechanical retention means may also be configured to allow the Venturi element to be separated from the aerosol-generating article.

[0018] The connecting element of the Venturi element may include mechanical retention means in the form of steps arranged on the periphery of the connecting element. Advantageously, this helps to hold the connecting element securely inside the connecting part of the aerosol-generating article after the connecting element is inserted into the connecting part. Alternatively, or additionally, the mechanical retention means may be configured as ribs, protrusions, hooks, or similar elements. Advantageously, this helps to hold the connecting element of the Venturi element securely inside the connecting part of the aerosol-generating article. The connecting element of the Venturi element may have a circular cross section. Alternatively, the connecting element of the Venturi element may have an oval, rectangular, or differently shaped cross section. Advantageously, this allows for a keyed configuration. A keyed configuration may mean that the connecting element of the Venturi element can only be inserted into the connecting part of the aerosol-generating article in a specific orientation. If the connecting part of the aerosol-generating article includes mechanical retention means, these mechanical retention means may be configured to engage or interlock with the mechanical retention means of the connecting element of the Venturi element.

[0019] The aerosol-generating article may be configured in a rod shape. The aerosol-generating article may be configured as a rod. The aerosol-generating article and the Venturi element may be configured in a rod shape. The aerosol-generating article and the Venturi element may be configured as a rod. A wrapping material, preferably wrapping paper, may be arranged to wrap the aerosol-generating article. The wrapping material may be arranged to wrap the aerosol-generating article and the Venturi element. Also, the individual components may be hidden by the wrapping paper. Advantageously, this means that a uniform appearance may be achieved.

[0020] As used herein, the term "rod" may be used to mean a generally cylindrical element of substantially circular, oval, or elliptical cross-section.

[0021] The removably attachable Venturi element may be provided with a marker disposed on the exterior of the Venturi element. The marker may be an optical marker or a tactile marker. The marker preferably comprises a color. Alternatively, or additionally, the marker may comprise a surface structure that identifies the marker. The marker may assist a user in attaching the Venturi element to the aerosol-generating article in the correct orientation. The marker may identify the correct attachment of the Venturi element to the aerosol-generating article. For example, the removably attachable Venturi element may be provided with a marker, preferably disposed on the exterior of the Venturi element, more preferably on the exterior of the connecting portion of the Venturi element, and most preferably on the wrapping material of the Venturi element.

[0022] The Venturi element may be configured to have two connection portions at opposite ends. The Venturi element may be attachable to the aerosol-generating article in one or more different orientations, preferably opposite orientations. The different connection portions may enable different aerosol generation experiences for a user. The first connection portion may correspond to a first attachment orientation of the Venturi element and the aerosol-generating article. The first attachment orientation may correspond to a first use experience. The second connection portion may correspond to a second attachment orientation of the Venturi element and the aerosol-generating article. The second attachment orientation may correspond to a second use experience.

[0023] The Venturi element may be provided with two or more markers, preferably disposed on the exterior of the Venturi element, more preferably disposed on the exterior of the connecting portion of the Venturi element, and most preferably disposed on the wrapping material of the Venturi element. For example, a Venturi element provided with two connecting portions may be configured to have one marker disposed on a first connecting portion of the Venturi element and a different marker on the exterior of a second connecting portion of the Venturi element. The markers may include information about the user. For example, the markers may indicate different usage experiences. Different orientations of attachment of the Venturi element to the aerosol-generating article may be indicated by different markers. For example, the markers may be colored markers. A first attachment orientation of the Venturi element may correspond to a smooth usage experience. The Venturi element may be configured to generate a smooth usage experience when attached to the aerosol-generating article in a first orientation. A second attachment orientation of the Venturi element may correspond to a strong usage experience. The Venturi element may be configured to generate a strong usage experience when attached to the aerosol-generating article in a second orientation.

[0024] Providing a Venturi element can enhance aerosol generation. Optimized aerosol droplets can be generated within the Venturi element. Conventionally, aerosol-generating articles have been provided containing elements such as a cooling section for cooling the airflow through the article and for generating inhalable aerosol within the article itself. By providing a Venturi element as in the present invention, the aerosol-generating article can be constructed in a simpler manner. For example, the cooling section can be omitted. The Venturi element can be configured to reduce the temperature of the air containing the vaporized aerosol-forming substrate flowing through the Venturi element. The Venturi element, in particular the dimensions of the Venturi element, are configured to generate an aerosol having an advantageous droplet size or an advantageous range of preferred droplet sizes or an advantageous droplet size distribution.

[0025] The venturi element is configured to utilize the Venturi effect. In other words, the Venturi element has a shape such that when a fluid flows through the Venturi element, a Venturi effect occurs. The Venturi element may be configured to utilize or provide the Venturi effect, as described below. The Venturi element may include an airflow channel disposed along a longitudinal axis of the Venturi element. The airflow channel may be a central airflow channel.

[0026] The airflow channel may be disposed along the longitudinal axis of the Venturi element such that the longitudinal axis of the aerosol-generating article may be aligned with the longitudinal axis of the Venturi element. In other words, the airflow channel of the Venturi element may be aligned with the aerosol-generating article such that air may be drawn through the aerosol-generating article and into the central channel of the Venturi element for subsequent inhalation by the user.

[0027] The Venturi effect is the reduction in pressure of a fluid during its flow through a constricted airflow passage. The structural elements of the Venturi element of the present invention are described in more detail below. The Venturi element includes a constricted airflow passage, also referred to as the central section. The fluid flowing through the Venturi element can be one of air, air with or entrained with a vaporized aerosol-forming substrate, and an aerosol. In the following, for simplicity, when the term "air" is used, this term can encompass air, air with or entrained with a vaporized aerosol-forming substrate, an aerosol, or any combination thereof. The air with the vaporized aerosol-forming substrate preferably flows through the central section of the Venturi element. After leaving the central section of the Venturi element, the air expands and accelerates, and as a result can cool. The cooling of the air can result in the formation of droplets and thus the generation of aerosols.

[0028] The venturi element may be located immediately downstream of the aerosol-generating article or may abut the aerosol-generating article.

[0029] As used herein, the terms "upstream" and "downstream" are used to describe the relative location of components, or portions of components, of the Venturi element and aerosol-generating article according to the invention with respect to the direction of air drawn through the Venturi element and aerosol-generating article during use. The term "downstream" may be understood to be closer to the mouth end than the distal end. The term "upstream" may be understood to be closer to the distal end than the mouth end.

[0030] The term "aerosol-generating article" as used herein refers to an article that includes an aerosol-forming substrate. The term "aerosol-generating substrate" as used herein refers to a material that has the ability to emit a volatile compound that can form an aerosol. For example, the aerosol-forming substrate may be arranged to generate an aerosol that can be inhaled directly through the user's mouth into the user's lungs. The aerosol-generating article may be disposable.

[0031] The aerosol-generating article may comprise a base portion including an aerosol-forming substrate, and a filter portion. The filter portion is preferably disposed downstream of the base portion. The Venturi element is preferably disposed downstream of the filter portion. The base portion may be disposed directly adjacent to the filter portion. The filter portion may be disposed directly adjacent to the Venturi element.

[0032] The filter portion may, for example, comprise a hollow tubular filter portion, preferably a hollow acetate tube (HAT), a fine hollow acetate tube (FHAT), or a plug of tow wound around a central corrugated tube, all of whose constructions are known from the manufacture of filter elements used in aerosol-generating articles. The filter portion preferably comprises a hollow central bore.

[0033] The filter portion may be made of any suitable material or combination of materials. For example, the filter portion may be made of one or more materials selected from the group consisting of cellulose acetate, cardboard, crimped paper (such as crimped heat-resistant paper or crimped parchment paper), and polymeric materials (such as low-density polyethylene (LDPE)). In a preferred embodiment, the filter portion is made of cellulose acetate.

[0034] The filter portion may comprise a hollow tubular element, hi a preferred embodiment, the filter portion comprises a hollow cellulose acetate tube.

[0035] The filter portion preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0036] The filter portion may have an outer diameter of about 4 mm to about 8 mm. For example, the filter portion may have an outer diameter of about 5 mm to about 6 mm. In some embodiments, the filter portion may have an outer diameter of about 5.3 mm. The filter portion may have a length of about 10 mm to about 25 mm. In some embodiments, the filter portion may have a length of about 13 mm.

[0037] The aerosol product article may be substantially cylindrical. However, alternatively, other cross-sections may be used. Indeed, the cross-section of the aerosol-generating article may vary along its length, for example by varying the cross-sectional shape or cross-sectional dimensions. The aerosol-generating article may be substantially elongated. The aerosol-generating article may have a length and a circumference substantially perpendicular to the length. The aerosol-forming substrate may be substantially cylindrical. The aerosol-forming substrate may be substantially elongated. The aerosol-forming substrate may also have a length and a circumference substantially perpendicular to the length.

[0038] The aerosol-generating article may have an overall length of 30mm to 60mm, preferably 40mm to 50mm, more preferably 45mm. The aerosol-generating article may have an outer diameter of approximately 4mm to 8mm, preferably 5mm to 6mm, more preferably about 5.3mm. In one embodiment, the aerosol-generating article has an overall length of approximately 45mm. Further, the aerosol-forming substrate may have a length of 10mm to 55mm, preferably 20mm to 55mm. The aerosol-generating article may comprise an outer paper wrapper.

[0039] As used herein, "aerosol-generating device" refers 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. The aerosol-generating device may be a device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol. The aerosol-generating device may include a housing, an electrical circuit, a power source, a cavity that is preferably configured as a heating chamber, and a heating element.

[0040] The electrical circuit may comprise a microprocessor, which may be a programmable microprocessor. The microprocessor may be part of the controller. The electrical circuit may comprise further electronic components. The electrical circuit may be configured to regulate the power supply to the heating element. Power may be supplied to the heating element continuously after activation of the system, or may be supplied intermittently, such as after every puff. Power may be supplied to the heating element in the form of current pulses. The electrical circuit is preferably configured to monitor the electrical resistance of the heating element and to control the power supply to the heating element depending on the electrical resistance of the heating element.

[0041] The device may include a power source (typically a battery) within the main body. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging and may have a capacity that allows for the storage of sufficient energy for one or more use experiences. For example, the power source may have a capacity sufficient to continuously generate aerosol for about six minutes, or a multiple of six minutes. In another embodiment, the power source may have a capacity sufficient to generate aerosol for multiple puffs.

[0042] The power source may be any suitable power source, for example a direct current voltage source such as a battery. In one embodiment, the power source is a lithium ion battery. Alternatively, the power source may be a nickel metal hydride battery, a nickel cadmium battery, or a lithium-based battery (e.g., a lithium cobalt battery, a lithium iron phosphate battery, a lithium titanate battery, or a lithium polymer battery).

[0043] The cavity may be configured to receive one or more aerosol-generating articles. The cavity may receive an aerosol-forming substrate. The cavity may enclose a heating element. The cavity may be a heating chamber. The received aerosol-forming substrate may be heated. The received aerosol-forming substrate may be heated to a temperature higher than ambient temperature. The temperature may be a temperature at which one or more volatile compounds are released from the aerosol-forming substrate and the aerosol-forming substrate does not burn.

[0044] The heating element may be an internal heating element, where "internal" refers to the aerosol-forming substrate. The internal heating element may take any suitable form.

[0045] The internal heating element may be one or more heated needles or rods extending through the centre of the aerosol-forming substrate, preferably arranged to at least partially penetrate an inner portion of the aerosol-forming substrate.

[0046] Alternatively, the internal heating element may take the form of a heating blade. Alternatively, the internal heater may take the form of a casing or substrate with different conductive portions or an electrically resistive metal tube. Other alternatives include heating wires or filaments, such as Ni-Cr (nickel chromium), platinum, tungsten, or alloy wires, or a heating plate. Optionally, the internal heating element may be disposed in or on a rigid carrier material. In one such embodiment, the electrically resistive heating element may be formed using a metal that has a well-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 a ceramic material, and then sandwiched in another insulating material, such as glass. A heater formed in this manner may be used to both heat the heating element and monitor its temperature during operation.

[0047] The heating element may be an external heating element, where "external" refers to the aerosol-forming substrate. The external heating element may take any suitable form. The heating element may be configured, and preferably arranged, to heat at least the outer surface of the aerosol-forming substrate or an aerosol-generating article comprising the aerosol-forming substrate.

[0048] Alternatively, the 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 may be shaped to fit around the cavity. Alternatively, the external heating element may take the form of a metal grid(s), flexible printed circuit board, molded circuit components (MIDs), ceramic heaters, flexible carbon fiber heaters, or may be formed using coating techniques such as plasma deposition on a substrate of suitable shape. The external heating element may also be formed using a metal that has a well-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 material. An external heating element formed in this manner may be used to both heat the external heating element and monitor its temperature during operation. The external heating element may be disposed around the perimeter of the cavity.

[0049] The internal or external heating element may comprise a heat sink or heat store, which comprises a material capable of absorbing and storing heat and then releasing the heat to the aerosol-forming substrate over a period of time. The heat sink may be formed of any suitable material, such as a suitable metal or ceramic material. In one embodiment, the material is one that has a high heat capacity (a suitable heat store material) or is capable of absorbing heat and then releasing it via a reversible process (such as a high temperature phase change). Suitable suitable heat store materials include silica gel, alumina, carbon, glass mat, glass fiber, minerals, metals or alloys (aluminum, silver or lead), and cellulosic materials (such as paper). Other suitable materials that release heat via a reversible phase change include paraffin, sodium acetate, naphthalene, wax, polyethylene oxide, mixtures or alloys of metals, metal salts, and eutectic salts. The heat sink or heat store may be disposed in direct contact with the aerosol-forming substrate and capable of transferring the stored heat directly to the substrate. Alternatively, heat stored in a heat sink or heat mass may be transferred to the aerosol-forming substrate by means of a thermal conductor such as a metal tube.

[0050] The heating element may heat the aerosol-forming substrate by conduction. The heating element may be in at least partial contact with the substrate or the carrier on which the substrate is disposed. Alternatively, heat from either an external or internal heating element may be conducted to the substrate by a thermally conductive element.

[0051] The aerosol generating device may include an external heating element, an internal heating element, or both an external and an internal heating element.

[0052] The Venturi element may be disposed so as to be connectable downstream of a heating chamber of the aerosol-generating device. The heating chamber may be configured for insertion of an aerosol-generating article into the heating chamber. When inserted into the heating chamber, the aerosol-generating article may be disposed upstream of the Venturi element.

[0053] The present invention may also relate to a system comprising an aerosol-generating article as described herein and a Venturi element as described herein, either separately from or as part of an aerosol-generating device as described herein. In some embodiments, the aerosol-generating article is separate from the Venturi element. In some embodiments, the aerosol-generating article is separate from the aerosol-generating device. In some embodiments, the Venturi element is separate from the aerosol-generating device. In some embodiments, both the aerosol-generating article and the Venturi element are separate from the aerosol-generating device, but not from each other. In some embodiments, both the aerosol-generating article and the Venturi element are separate from the device and separate from each other. In some embodiments, the aerosol-generating article is engageable with the Venturi element. In some embodiments, the aerosol-generating article is engageable with the aerosol-generating device. In some embodiments, the Venturi element is engageable with the aerosol-generating device. In some embodiments, the aerosol-generating article is reversibly engageable with the Venturi element. In some embodiments, the aerosol-generating article is reversibly engageable with the aerosol-generating device. In some embodiments, the venturi element is reversibly engagable with the aerosol generating device.

[0054] The Venturi element may include an airflow channel, which may include an inlet portion, a central portion, and an outlet portion, where the inlet portion may be configured to converge towards the central portion and the outlet portion may be configured to diverge from the central portion.

[0055] The inlet portion may be disposed adjacent an upstream end of the Venturi element. The outlet portion may be disposed adjacent a downstream end of the Venturi element. The inlet portion may be disposed opposite the outlet portion. The center portion may be disposed between the inlet portion and the outlet portion. The inlet portion may be disposed in direct abutment with the center portion. The center portion may be disposed in direct abutment with the outlet portion. The inlet portion may be configured to allow air to enter the Venturi element. The outlet portion may be configured to allow air to be drawn from the Venturi element. The inlet portion, center portion, and outlet portion may be fluidly connected to one another. The inlet portion, center portion, and outlet portion together may form an airflow channel of the Venturi element. The inlet portion, center portion, and outlet portion together may enable airflow through the Venturi element.

[0056] The term "converging" may mean that the inner diameter of the inlet section may decrease towards the central section. In other words, the inner diameter of the inlet section may decrease from the upstream direction to the downstream direction. The inlet section may have a hollow cone shape. The inlet section may taper towards the central section.

[0057] The term "diverging" may mean that the inner diameter of the outlet section may increase towards the downstream end of the Venturi element. In other words, the inner diameter of the outlet section may increase from the upstream direction to the downstream direction. The outlet section may have a hollow cone shape. The outlet section may taper towards a central section. The central section may have a constant diameter.

[0058] The inlet, middle, and outlet sections may have a circular cross section. The inlet, middle, and outlet sections may have different cross sections. One or more of the inlet, middle, and outlet sections may have a circular, oval, rectangular, or differently shaped cross section. The only requirement of the Venturi element is that the cross section of the middle section is smaller than the cross section of the outlet section, so that the middle section constitutes a constricted air flow path. The middle section is optional. The middle section is the section with the smallest diameter between the inlet and outlet sections. The middle section may have any suitable length, preferably the middle section has a length of less than 4 mm, more preferably the middle section has a length of less than 2 mm, and most preferably the middle section has a length of less than 1 mm. In a particularly preferred embodiment, there is no middle section, and the inlet and outlet sections directly abut each other. In this case, the term "middle section" may be used to refer to the cross section of the Venturi section with the smallest constriction, even if the inlet and outlet sections physically contact at that cross section. In this embodiment, the length of the middle section may in principle be zero.

[0059] The Venturi element may be configured as a mouthpiece of the aerosol generating device. The Venturi element may be configured as a mouthpiece or as a part of the mouthpiece. The mouthpiece is preferably configured as a reusable mouthpiece for use with multiple aerosol generating articles. Conventionally, a cooling section has been provided in an aerosol generating article for the purpose of cooling the airflow and enabling aerosol generation. Such a cooling section may be omitted by using a Venturi element configured as a mouthpiece according to the present invention.

[0060] The Venturi element may be part of the aerosol generation device. The Venturi element may be provided separately from the aerosol generation device but connectable to the aerosol generation device, such as by a hinge. The Venturi element may be an integral part of the aerosol generation device. The Venturi element may be configured as a mouthpiece of the aerosol generation device. The Venturi element may be configured as a separate mouthpiece connectable to the aerosol generation device.

[0061] The aerosol-forming article may comprise a portion of an aerosol-forming substrate. The aerosol-forming substrate is a substrate capable of releasing a volatile compound capable of forming an aerosol. The aerosol-forming substrate may conveniently be a portion of the aerosol-forming article or the aerosol-generating article. The volatile compound may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may comprise nicotine. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds that are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco-containing material. The aerosol-forming substrate may be a non-liquid aerosol-forming substrate. Alternatively, the aerosol-forming substrate may comprise both non-liquid and liquid components. As a further alternative, the aerosol-forming substrate may be provided in liquid form.

[0062] In some embodiments of the present invention, the aerosol-generating system may comprise an aerosol-generating article containing a non-liquid aerosol-forming substrate and a Venturi element. The Venturi element may be configured to be attachable to the aerosol-generating article.

[0063] The aerosol-forming substrate may include at least one aerosol former. The aerosol former is any suitable known compound or mixture of compounds that facilitates the formation of a dense, stable aerosol during use and is substantially resistant to thermal decomposition at the operating temperature of the system. Suitable aerosol formers are, for example, polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.). The aerosol former may be a polyhydric alcohol or a mixture thereof (such as triethylene glycol, 1,3-butanediol, and glycerin). The aerosol former may be propylene glycol. The aerosol former may include both glycerin and propylene glycol.

[0064] Preferably, the amount of aerosol former is between 6 and 20 percent by weight based on the dry weight of the aerosol-forming substrate, more preferably, the amount of aerosol former is between 8 and 18 percent by weight based on the dry weight of the aerosol-forming substrate, and most preferably, the amount of aerosol former is between 10 and 15 percent by weight based on the dry weight of the aerosol-forming substrate. In some embodiments, the amount of aerosol former has a target value of about 13 percent by weight based on the dry weight of the aerosol-forming substrate. The most efficient amount of aerosol former also depends on whether the aerosol-forming substrate comprises a plant lamina or homogenized plant material. For example, the type of substrate, among other factors, determines the extent to which the aerosol former can facilitate the release of a substance from the aerosol-forming substrate.

[0065] The aerosol-forming substrate may comprise a non-liquid aerosol-forming substrate. The aerosol-forming substrate may be a non-liquid aerosol-forming substrate. The aerosol-forming substrate may comprise a non-liquid aerosol-forming substrate. The non-liquid aerosol-forming substrate may comprise a plant-derived material. The non-liquid aerosol-forming substrate may comprise tobacco. The non-liquid aerosol-forming substrate may comprise homogenized plant-derived material, including homogenized tobacco made by a papermaking process or a casting process. An aerosol-generating article comprising a non-liquid aerosol-forming substrate comprising tobacco may be referred to as a tobacco stick. The aerosol-forming substrate is preferably non-liquid. The aerosol-forming substrate preferably comprises a non-liquid. The non-liquid aerosol-forming substrate may comprise at least one aerosol former. In some embodiments, the at least one aerosol former may be at least one of the compounds listed above. For example, the aerosol-forming substrate may comprise an aerosol former, such as a polyhydric alcohol. For example, during the manufacture of the aerosol-generating article, the at least one aerosol former may be absorbed by the non-liquid aerosol-forming substrate. For example, during the manufacture of the aerosol-generating article, at least one aerosol former may be absorbed by a plant-derived material, such as homogenized tobacco. Upon heating of the non-liquid aerosol-forming substrate, the aerosol former may evaporate. The aerosol former may form volatile compounds with the non-liquid aerosol-forming substrate, such as nicotine, or a nicotine salt, to form an aerosol.

[0066] Advantageously, by using natural plant material lamina, a more natural taste and appearance of the aerosol-generating article can be achieved. The term "lamina" refers to the leaf blade portion of a plant without a stem.

[0067] Where the aerosol-forming substrate comprises a non-liquid aerosol-forming substrate, it is preferably a solid aerosol-forming substrate, which may for example comprise one or more of powders, granules, pellets, pieces, spaghetti, strips or sheets including one or more of herb leaves, tobacco leaves, tobacco stem fragments, homogenized sheet tobacco, preferably reconstituted tobacco, more preferably cast leaf tobacco, extruded tobacco and expanded tobacco.

[0068] The non-liquid aerosol-forming substrate may be an electrically heated tobacco product (EHTP). In some embodiments, all of the tobacco in the EHTP may be homogenized sheet tobacco, preferably reconstituted tobacco, preferably cast leaf tobacco made from tobacco powder, water, glycerin, guar gum and cellulose fibers. The non-liquid aerosol-forming substrate may be made from cast leaf tobacco. The cast leaf tobacco may be gathered and crimped. The cast leaf tobacco may be produced in a sheet of homogenized tobacco material by a reconstitution process. The reconstitution process may be a "cast leaf" process or casting. The homogenized tobacco material sheet may be gathered. The homogenized tobacco material sheet may be formed by a casting process of the type that generally involves casting a slurry including particulate tobacco and one or more binders onto a conveyor belt or other support surface, drying the cast slurry to form a homogenized tobacco material sheet, and removing the homogenized tobacco material sheet from the support surface. For example, in certain embodiments, sheets of homogenized tobacco material for use in the present invention may be formed from a slurry including particulate tobacco, guar gum, cellulose fibers, and glycerin by a casting process.

[0069] As used herein, the term "gathered" means that the homogenized tobacco material has been rolled, folded, or otherwise compressed or contracted substantially transverse to the cylindrical axial direction of the rod.

[0070] The term "sheet" may refer to a laminar element having a width and length that is substantially greater than its thickness.

[0071] The term "length" may refer to the dimension of the rod along its cylindrical axis.

[0072] The term "width" may refer to the dimension substantially perpendicular to the cylindrical axis of the rod.

[0073] The rod may be an integral part of the filter portion of the aerosol-generating article. The rod may be an integral part of the aerosol-generating substrate. The rod may comprise a sheet of homogenized tobacco material surrounded by wrapping material. The rod may advantageously comprise a sheet of homogenized tobacco material exhibiting a significantly lower weight standard deviation than rods comprising shredded tobacco material. The weight of a rod of a particular length may be determined by the density, width and thickness of the homogenized tobacco material sheet assembled to form the rod. The weight of a rod of a particular length may be adjusted by controlling the density and dimensions of the homogenized tobacco material sheet. This reduces the weight discrepancy between rods of the same dimensions of the present invention, thereby resulting in a lower rejection rate of rods with weights outside a selected acceptance range. Rods comprising a sheet of homogenized tobacco material advantageously exhibit a more uniform density than rods comprising shredded tobacco material.

[0074] Including an aggregate of homogenized sheets of tobacco material in a rod advantageously significantly reduces the risk of loose ends compared to rods containing pieces of tobacco material.

[0075] The term "homogenized tobacco" as used herein refers to a material formed by agglomerating particulate tobacco. The homogenized tobacco may be in the form of a sheet. The homogenized tobacco material may have an aerosol former content of greater than 5% on a dry weight basis. Alternatively, the homogenized tobacco material may have an aerosol former content of 5-30% by weight on a dry weight basis. The homogenized tobacco material sheet may be formed by agglomerating particulate tobacco obtained by grinding or otherwise combining one or both of tobacco lamina and tobacco stems. Alternatively, or additionally, the homogenized tobacco material sheet may include one or more of tobacco dust, tobacco fines, and other particulate tobacco by-products formed, for example, during tobacco processing, handling, and shipping. The homogenized tobacco material sheet may include one or more inherent binders (i.e., tobacco intrinsic binders), one or more extrinsic binders (i.e., tobacco extrinsic binders), or combinations thereof to aid in the cohesion of the particulate tobacco, although alternatively or additionally, the homogenized tobacco material sheet may include other additives including, but not limited to, tobacco and non-tobacco fibers, aerosol formers, humectants, plasticizers, flavorants, fillers, aqueous and non-aqueous solvents, and combinations thereof.

[0076] The solid aerosol-forming substrate may be in loose form or may be provided in a suitable container or cartridge. Optionally, the solid aerosol-forming substrate may contain additional tobacco or non-tobacco volatile flavor compounds that are released upon heating of the substrate. The solid aerosol-forming substrate may also contain capsules, for example, containing additional tobacco or non-tobacco volatile flavor compounds, which may melt during heating of the solid aerosol-forming substrate.

[0077] The non-liquid aerosol-forming substrate may be deposited on the surface of the carrier, for example in the form of a sheet, foam, gel, or slurry. The non-liquid aerosol-forming substrate may be deposited on the entire surface of the carrier or, alternatively, may be deposited in a pattern to provide a non-uniform flavor delivery during use.

[0078] The non-liquid aerosol-forming substrate preferably comprises cut filler. In this document, "cut filler" is used to refer to blends of finely cut plant material, particularly leaf lamina, processed stems and ribs, homogenized plant material, such as those made into sheet form using a casting or papermaking process. The cut filler may also comprise other post-cut filler tobacco or casings. According to a preferred embodiment of the present invention, the cut filler comprises at least 25 percent of plant leaf lamina, more preferably at least 50 percent of plant leaf lamina, even more preferably at least 75 percent of plant leaf lamina, and most preferably at least 90 percent of plant leaf lamina. The plant material is preferably one of tobacco, mint, tea, and clove, although the present invention is equally applicable to other plant materials having the ability to release a substance upon application of heat that can then form an aerosol.

[0079] The tobacco plant material preferably includes one or more lamina of bright tobacco, dark tobacco, aromatic tobacco, and filler tobacco. Bright tobacco is a tobacco that generally has large, light-colored leaves. Throughout this specification, the term "bright tobacco" is used for flue-cured tobacco. Examples of bright tobacco include Chinese flue-cured tobacco, Brazilian flue-cured tobacco, American flue-cured tobacco (such as Virginia tobacco), Indian flue-cured tobacco, Tanzanian flue-cured tobacco, or other African flue-cured tobacco. Bright tobacco is characterized by a high sugar-to-nitrogen ratio. From a sensory perspective, bright tobacco is a tobacco type with a spicy and lively sensation after curing. According to the present invention, bright tobacco is tobacco having a reducing sugar content of about 2.5 percent to about 20 percent based on dry weight of the leaf and a total ammonia content of less than about 0.12 percent based on dry weight of the leaf. Reducing sugars include, for example, glucose or fructose. Total ammonia includes, for example, ammonia and ammonia salts. Dark tobacco is tobacco that generally has large, dark leaves. Throughout this specification, the term "dark tobacco" is used for air-cured tobacco. In addition, dark tobacco may be fermented. Tobacco that is primarily used for chewing tobacco, snuff, cigar tobacco, and pipe blends are also included in this category. Typically, these dark tobaccos are air-cured and sometimes fermented. From a sensory perspective, dark tobacco is a tobacco type with a smoky, dark cigar-type sensation after curing. Dark tobacco is characterized by a low sugar-to-nitrogen ratio. Examples for dark tobacco are Burley Malawi or other African Burley, dry cured dark Brazilian Galpao, sun cured or air cured Indonesian Kasturi.According to the present invention, dark tobacco is tobacco with a reducing sugar content of less than about 5 percent based on dry weight of the leaf and a total ammonia content of up to about 0.5 percent based on dry weight of the leaf. Aromatic tobacco is tobacco with small, often light-colored leaves. Throughout this specification, the term "aromatic tobacco" is used in contrast to other tobaccos with high aromatic content, such as essential oils. From a sensory perspective, aromatic tobacco is a tobacco type with a spicy and aromatic sensation after curing. Examples of aromatic tobacco are Greek Orient, Orient Turkey, semi-orient tobacco but flame-cured, US Burley such as Perique, Rustica, US Burley or Maryland. Filler tobacco is not a specific tobacco type, but includes tobacco types that are used in blends and are primarily used to complement other tobacco types that do not bring a specific characteristic aroma direction to the final product. Examples of filler tobacco are the stem, midrib, or petiole of other tobacco types. A specific example may be flue-dried lower petiole flue-dried stems from Brazil.

[0080] The cut filler suitable for use in the present invention may generally resemble the cut filler used in conventional smoking articles. The cut width of the cut filler is preferably 0.3 mm to 2.0 mm, more preferably 0.5 mm to 1.2 mm, and most preferably 0.6 mm to 0.9 mm. The cut width may play a role in the distribution of heat inside the base portion of the article. The cut width may also play a role in the draw resistance of the article. Additionally, the cut width may affect the overall density of the base portion.

[0081] The strand length of the cut filler is somewhat of a random value, since the length of the strand depends on the overall size of the object from which the strand is cut. Nevertheless, longer strands can be cut by conditioning the material prior to cutting, for example by controlling the moisture content and overall fineness of the material. The strands preferably have a length of about 10 millimeters to about 40 millimeters before the strands are formed into the substrate section. Obviously, if the strands are disposed in a longitudinal substrate section in which the longitudinal extension of the section is less than 40 millimeters, the final substrate section may contain strands that are on average shorter than the initial strand length. The strand length of the cut filler is preferably such that about 20 percent to 60 percent of the strands extend along the entire length of the substrate section. This prevents the strands from easily detaching from the substrate section.

[0082] The weight of the non-liquid aerosol-forming substrate is between 80 milligrams and 400 milligrams, preferably between 150 milligrams and 250 milligrams, more preferably between 170 milligrams and 220 milligrams. Usually, this amount of aerosol-forming substrate allows sufficient material for the formation of an aerosol. In addition, in light of the aforementioned constraints on diameter and size, this allows a balanced density of the aerosol-forming substrate between energy uptake, withdrawal resistance and fluid passage within the substrate section in which the substrate contains the plant material.

[0083] The non-liquid aerosol-forming substrate portion of the aerosol-generating article may have a length of from 20 mm to 40 mm, preferably from about 25 mm to 35 mm. In some embodiments, the aerosol-forming substrate portion of the aerosol-generating article may have a length of approximately 32 mm. The aerosol-forming substrate portion of the aerosol-generating article may have an outer diameter of from approximately 4 mm to approximately 8 mm. For example, the aerosol-forming substrate portion of the aerosol-generating article may have an outer diameter of from approximately 5 mm to approximately 6 mm. In some embodiments, the aerosol-forming substrate portion may have an outer diameter of approximately 5.3 mm.

[0084] The term "non-liquid aerosol-forming substrate" as used herein relates to a substrate capable of releasing a volatile compound capable of forming an aerosol. The substrate may be non-liquid. The substrate may be provided as a gel. The substrate may be viscous. The substrate may be provided as a viscous gel. The volatile compound may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may conveniently be part of an aerosol-generating article. The aerosol-forming substrate may be a liquid aerosol-forming substrate. The liquid aerosol-forming substrate may include other additives and ingredients, such as flavorants. When the aerosol-forming substrate is provided in liquid form, in liquid aerosol-forming substrates, certain physical properties of the substrate, such as vapor pressure or viscosity, are chosen to be suitable for use in an aerosol generating system. The liquid preferably comprises a tobacco-containing material, including volatile tobacco flavor compounds that are released from the liquid when heated. The liquid may include water, ethanol, or other solvents, plant extracts, nicotine solutions, and natural or artificial flavors. The liquid preferably further comprises an aerosol former. Examples of suitable aerosol formers are glycerin and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of about 0.5% to about 10% (e.g., about 2%).

[0085] When the aerosol-forming substrate is provided in liquid form, the liquid aerosol-forming substrate may be accommodated in a liquid storage portion of the aerosol-generating article. The aerosol-generating article may be configured as a cartridge. The liquid storage portion is adapted to store the liquid aerosol-forming substrate to be supplied to a heating element of the aerosol-generating device. Alternatively, the cartridge itself may include a heating element for vaporizing the liquid aerosol-forming substrate. In this case, the aerosol-generating device may not include a heating element and may only supply electrical energy towards the heating element of the cartridge when the cartridge is received in the aerosol-generating device. The liquid storage portion may include a coupling such as a self-healing pierceable membrane to facilitate the supply of the liquid aerosol-forming substrate towards the heating element. The membrane prevents undesired leakage of the liquid aerosol-forming substrate stored in the liquid storage portion. A needle-like hollow tube may be provided for piercing the membrane. The liquid storage portion may be configured as a replaceable tank or container.

[0086] The cartridge may have any suitable shape and size. For example, the cartridge may be substantially cylindrical. The cross-section of the cartridge may be, for example, substantially circular, oval, square, or rectangular.

[0087] The cartridge may comprise a housing. The housing may comprise a base and one or more side walls extending from the base. The base and the one or more side walls may be integrally formed. The base and the one or more side walls may be distinct elements attached or fixed to each other. The housing may be a rigid housing. As used herein, the term "rigid housing" is used to mean a free-standing housing. The rigid housing of the cartridge may provide mechanical support to the heating element. The cartridge may comprise one or more flexible walls. The flexible walls may be configured to fit the volume of the liquid aerosol-forming substrate stored in the cartridge. The cartridge preferably includes a liquid storage portion that may comprise a flexible wall, as described above. The cartridge may comprise a rigid housing, and the liquid storage portion that comprises the flexible wall may be contained within the rigid housing. The housing of the cartridge may comprise any suitable material. The cartridge may comprise a substantially fluid-impermeable material. The housing of the cartridge may comprise a transparent or translucent portion such that the liquid aerosol-forming substrate stored in the cartridge may be visible to the user through the housing. The cartridge may be configured such that the aerosol-forming substrate stored within the cartridge is protected from ambient air. The cartridge may be configured such that the aerosol-forming substrate stored within the cartridge is protected from light. This may reduce the risk of degradation of the substrate and may maintain a high level of hygiene.

[0088] The cartridge may be substantially sealed. The cartridge may comprise one or more outlets for the liquid aerosol-forming substrate stored in the cartridge to flow from the cartridge to the aerosol generating device. The cartridge may comprise one or more semi-open inlets. This may allow ambient air to enter the cartridge. The one or more semi-open inlets may be semi-permeable membranes or one-way valves that are permeable to allow ambient air to enter the cartridge and impermeable to substantially prevent air and liquid inside the cartridge from exiting the cartridge. The one or more semi-open inlets may allow air to pass into the cartridge under certain conditions. The cartridge may be refillable. Alternatively, the cartridge may be configured as a replaceable cartridge. The aerosol generating device may be configured to receive the cartridge. Once the initial cartridge is consumed, a new cartridge may be installed in the aerosol generating device.

[0089] The liquid aerosol-forming substrate may be held in a container. Alternatively or additionally, the liquid aerosol-forming substrate may be absorbed into a porous carrier material. The porous carrier material may be made of any suitable absorbent plug or body, such as foamed metal or plastic material, polypropylene, terylene, nylon fiber, or ceramic. The liquid aerosol-forming substrate may be held in the porous carrier material before using the aerosol generating device, or alternatively, the liquid aerosol-forming substrate material may be released into the porous carrier material during or immediately before use. For example, the liquid aerosol-forming substrate may be provided in a capsule. The shell of the capsule preferably melts upon heating and releases the liquid aerosol-forming substrate into the porous carrier material. The capsule may optionally contain a non-liquid in combination with the liquid.

[0090] Alternatively, the carrier may be a nonwoven fabric or bundle of fabrics into which the tobacco components have been incorporated. The nonwoven fabric or bundle of fabrics may comprise, for example, carbon fabric, natural cellulose fabric, or cellulose derivative fabrics. The aerosol generating device preferably includes a means for retaining a liquid.

[0091] The Venturi element may include an airflow channel, which may include an inlet portion, a central portion, and an outlet portion, where the inlet portion may be configured to converge towards the central portion and the outlet portion may be configured to diverge from the central portion.

[0092] In the central portion, the pressure of the air or aerosol flowing through the central portion decreases and the flow velocity increases. The central portion is particularly relevant for defining the flow resistance during use, more preferably the withdrawal resistance. For example, if the diameter of the central portion decreases, the withdrawal resistance increases. Generally, the withdrawal resistance may depend on the cross-sectional area of ​​the central portion. The cross-sectional area of ​​the central portion may be configured to optimize the withdrawal resistance to a desired value. A comfortable smoking experience may be influenced in a desired manner by selecting a particular diameter or cross-sectional area of ​​the central portion. In some embodiments, the length of the central portion may have some effect on the withdrawal resistance. For example, if the length of the central portion increases. In some embodiments, the preferred optimized withdrawal resistance of the Venturi element only may be 5 mmWG to 60 mmWG, preferably 5 mmWG to 30 mmWG, more preferably 10 mmWG to 15 mmWG. In some embodiments, the preferred optimized withdrawal resistance of the Venturi element only may be approximately 12 mmWG. In some embodiments, the optimized withdrawal resistance of both the device and the consumable may be between 50mmWG and 60mmWG, preferably between 52mmWG and 56mmWG.

[0093] The angle between the longitudinal axis of the inlet section and the inner wall of the inlet section may be referred to as the inlet angle. The longitudinal axis of the inlet section may be the same as the longitudinal axis of the Venturi element. The inlet angle may affect the conversion of the vaporized aerosol-forming substrate to an aerosol. The inlet angle may contribute to pressure changes that affect the conversion of the vaporized aerosol-forming substrate to an aerosol. In some embodiments, a small inlet angle may be associated with a relatively long inlet length of the inlet section. The appropriate inlet angle and inlet length may be selected depending on the type of aerosol-forming substrate. For example, in some embodiments, a liquid aerosol-forming substrate, such as e-liquid, may require a relatively small inlet angle, and a non-liquid aerosol-forming substrate, such as tobacco, may require a relatively large inlet angle.

[0094] The angle between the longitudinal axis of the outlet section and the inner wall of the outlet section may be referred to as the outlet angle. The longitudinal axis of the outlet section may be the same as the longitudinal axis of the Venturi element.

[0095] The exit angle can affect the delivery zone of the aerosol. The delivery zone can be a region along the oral cavity of the user. The delivery zone can be a region generally located along the longitudinal axis along the oral cavity of the user. For example, the delivery zone can be the tip of the tongue of the user, the middle of the tongue of the user, the back of the tongue of the user or the back of the throat of the user, or any other perceptible region along the oral cavity of the user.

[0096] The vaporized aerosol-forming substrate may be converted into an aerosol. The spatial distance that the vaporized aerosol-forming substrate covers before being converted into an aerosol may be called the vapor path. This conversion may occur within the airflow channel of the Venturi element. The vapor path may be influenced by pressure changes. Pressure changes may have an effect on the vapor path. Pressure changes may initiate the conversion of the vaporized aerosol-forming substrate into an aerosol. The pressure changes may be controlled by the inlet angle. The vapor path may not be too long or too short. If the vapor path is too long, the vaporized aerosol-forming substrate may accumulate inside the Venturi element and condense there. The condensed aerosol-forming substrate may leak out of the system. Leaking from the system may be uncomfortable for the user. On the other hand, if the vapor path is too short, there may not be enough vaporized aerosol-forming substrate to convert into an aerosol. The desired vapor path may depend on the type of substrate, in particular whether a liquid or non-liquid substrate is used as described below.

[0097] The type of vaporized aerosol-forming substrate may affect the vapor path. For example, liquid aerosol-forming substrates, such as e-liquids, have a relatively short vapor path. For example, an e-liquid aerosol-forming substrate may have a typical vapor path of approximately 2 mm to 5 mm, such as 3 mm. In comparison, non-liquid aerosol-forming substrates, such as tobacco, have a relatively long vapor path. For example, an aerosol-forming substrate comprising tobacco cast leaf may have a vapor path of approximately 10 mm to 15 mm, such as 12 mm.

[0098] Exit angle can affect vapor path The vapor path of the aerosol exiting the Venturi element can be influenced in a desired manner by selecting a particular exit angle.

[0099] The aerosol flow trajectory, or at least the delivery zone within the user's oral cavity, can be influenced by the exit angle. The aerosol trajectory or delivery zone exiting the Venturi element can be influenced in a desired manner by selecting a particular exit angle. Additionally, the exit velocity of the aerosol can be influenced by the exit angle. Exit velocity can refer to the velocity of the aerosol flow as it exits the Venturi element. The zone of aerosol delivery in the user's mouth can be influenced in a desired manner by one or more of the aerosol trajectory and the aerosol velocity exiting the Venturi element. Thus, the zone of aerosol delivery can be optimized by selecting a particular exit angle. The zone of aerosol delivery can be within the user's oral cavity. The delivery zone can be a region generally located along a longitudinal axis along the oral cavity of the user. The delivery zone can be the tip of the user's tongue. The delivery zone can be the center of the user's tongue. The delivery zone can be the back of the user's tongue. The delivery zone can be the back of the user's throat. The delivery zone can be any other perceptible region along the oral cavity of the user. Delivery zones described as "towards the front," "forward," "at the front of the mouth," "further forward," etc., refer to delivery zones that are relatively closer to the user's lips or front teeth, such as incisors, in the oral cavity, than to the user's lips or front teeth, such as incisors, in the oral cavity. Delivery zones described as "towards the rear," "rear," "at the rear of the mouth," "further rearward," etc., refer to delivery zones that are relatively closer to the user's lips or front teeth, such as incisors, in the oral cavity, than to the user's lips or front teeth, such as incisors, in the oral cavity.

[0100] Some users may desire a delivery experience near the front of the mouth. Some users may desire a delivery experience near the back of the mouth. This delivery experience may be affected by the exit angle. For example, if the exit angle is large, the aerosol flavors may be delivered near the back of the user's mouth. If the exit angle is large, the aerosol delivery may provide a fuller mouthfeel. If the exit angle is small, the aerosol flavors may be delivered near the front of the user's mouth.

[0101] In some embodiments, when the exit angle is large, the length of the exit section is short. The exit velocity of the aerosol may be high. Thus, the delivery experience may be closer to the back of the user's throat. In some embodiments, when the exit angle is small, the length of the exit section is large. The exit velocity of the aerosol may be low.

[0102] The inlet portion may be configured to converge towards the central portion at an inlet angle of 1 degree to 20 degrees, preferably 16 degrees to 20 degrees, more preferably 17 degrees to 19 degrees, and most preferably 18 degrees. This inlet angle is particularly preferred when a non-liquid aerosol-forming substrate is used. In an alternative embodiment of the invention, the inlet portion may be configured to converge towards the central portion at an inlet angle of 1 degree to 20 degrees, preferably 5 degrees to 15 degrees, more preferably 8 degrees to 11 degrees, and most preferably 9.5 degrees.

[0103] The outlet portion may be configured to diverge from the central portion at an outlet angle of 2 degrees to 10 degrees, preferably 4 degrees to 8 degrees, more preferably 6 degrees. This outlet angle is particularly preferred when a non-liquid aerosol-forming substrate is used. In an alternative embodiment of the invention, the outlet portion may diverge from the central portion at an outlet angle of 2 degrees to 10 degrees, preferably 3 degrees to 6 degrees, more preferably 4.4 degrees.

[0104] These particular inlet and outlet angles have proven advantageous when the aerosol-generating article comprises a non-liquid aerosol-forming substrate: after evaporation of the non-liquid aerosol-forming substrate, the droplet size or droplet size distribution of the generated aerosol can be optimized by selecting the inlet angles specified above.

[0105] In some embodiments, the vapor path using the non-liquid aerosol-forming substrate may be 10 mm to 14 mm, preferably 11 mm to 13 mm, more preferably 12 mm. The transformation of the vaporized non-liquid aerosol-forming substrate may occur in the cooling portion of the aerosol-generating article and in the Venturi element, preferably in the airflow channel of the Venturi element, more preferably at the inlet portion of the Venturi element. The transformation preferably occurs partly in the cooling portion and partly in the Venturi element. Thus, the vapor path may be partly in the aerosol-generating article and partly in the Venturi element. After vaporization of the non-liquid aerosol-forming substrate, the vapor path may be optimized by selecting the inlet angle specified above. In this aspect, a high pressure change may be utilized at the inlet portion of the Venturi element. This particular pressure change may be provided by using an inlet angle such as 18 degrees.

[0106] In addition to optimizing droplet size with the inlet angle, the above specified exit angles may optimize the desired delivery experience. The inlet section may be configured to converge toward a central section at an inlet angle of 2 degrees to 10 degrees, preferably 4 degrees to 8 degrees, more preferably 6 degrees. This inlet angle is particularly preferred when a liquid aerosol-forming substrate is used.

[0107] The exit portion may be configured to diverge from the central portion at an exit angle of between 16 degrees and 20 degrees, preferably between 17 degrees and 19 degrees, more preferably 18 degrees. This exit angle is particularly preferred when a liquid aerosol-forming substrate is used.

[0108] These particular angles have proven advantageous when the aerosol-generating article is an aerosol-generating article that includes a liquid aerosol-forming substrate. The vapor path of the vaporized liquid aerosol-forming substrate may be shorter than the vapor path of the vaporized non-liquid aerosol-forming substrate. The vapor path using the liquid aerosol-forming substrate may be 1 mm to 4 mm, preferably 2 mm to 3 mm. The conversion of the vaporized liquid aerosol-forming substrate may occur within the Venturi element, preferably within the airflow channel of the Venturi element, more preferably within the inlet portion of the Venturi element. In aspects using a liquid aerosol-forming substrate, the vapor path may be shorter compared to when a non-liquid aerosol substrate is used. For example, a vapor path of 2 mm to 3 mm may be provided by a particular pressure change. In some embodiments, the particular pressure change may be a relatively low pressure change. This particular pressure change may be provided by using a particular inlet angle described herein, such as 6 degrees. Such an inlet angle may be sufficient to optimize the vapor path of the vaporized liquid aerosol-forming substrate.

[0109] In addition to optimizing droplet size with the entrance angle, the exit angle specified above can optimize the desired delivery experience.

[0110] When using an aerosol-generating article having a non-liquid aerosol-forming substrate, the axial length of the inlet portion may be from 3mm to 10mm, preferably from 5mm to 9mm, more preferably from 7.7mm.In an alternative embodiment of the invention, the axial length of the inlet portion may be from 1mm to 10mm, preferably from 2mm to 7mm, more preferably from 2.5mm to 4mm, most preferably 3mm.

[0111] The axial length of the outlet portion may be between 14mm and 35mm, preferably between 19mm and 28mm, more preferably between 23mm. In alternative embodiments of the invention, the axial length of the outlet portion may be between 10mm and 50mm, preferably between 14mm and 35mm, more preferably between 20mm and 30mm, most preferably 26mm.

[0112] When using an aerosol-generating article having a liquid aerosol-forming substrate, the axial length of the inlet portion may be from 14mm to 35mm, preferably from 19mm to 28mm, more preferably 23mm.

[0113] When using an aerosol-generating article having a liquid aerosol-forming substrate, the axial length of the outlet portion may be from 3mm to 10mm, preferably from 5mm to 9mm, more preferably 7.7mm.

[0114] When using an aerosol-generating article having a non-liquid aerosol-forming substrate or having a liquid aerosol-forming substrate, the axial length of the central portion may be from 2 mm to 5 mm, preferably from 3 mm to 4 mm, more preferably 3.2 mm. It is particularly preferred that the central portion is constituted by a transition between the inlet portion and the outlet portion. In some embodiments, the central portion may not have a substantial length or may be, for example, less than 1 mm. In alternative embodiments of the invention, the axial length of the central portion may be from 0 mm to 8 mm, preferably less than 6 mm, more preferably less than 2 mm, most preferably less than 1 mm.

[0115] When using an aerosol-generating article having a non-liquid aerosol-forming substrate or having a liquid aerosol-forming substrate, the inner diameter of the central portion may be from 0.5mm to 1.5mm, preferably from 0.8mm to 1.2mm, more preferably from 1mm. In an alternative embodiment of the invention, the inner diameter of the central portion is from 0.5mm to 5mm, preferably from 1mm to 4mm, more preferably from 1.5mm to 3mm, most preferably 2mm.

[0116] The maximum inner diameter of the inlet portion may be from 1 mm to 10 mm, preferably from 2 mm to 5 mm, more preferably from 2.5 mm to 4 mm, and most preferably 3 mm.

[0117] The maximum inner diameter of the outlet portion is 3 mm to 15 mm, preferably 4 mm to 10 mm, more preferably 5 mm to 7 mm, and most preferably 6 mm.

[0118] The outlet section may include a screw thread. Preferably, the screw may include a helical screw thread. The screw thread may be configured to generate a swirling airflow. The screw thread may generate a vortex. The screw thread may be disposed on an inner wall of the outlet section. The screw thread may be disposed along an entire length of the outlet section. The screw thread may be disposed along a portion of the outlet section, preferably adjacent a downstream end of the outlet section. The pitch of the screw thread may be between 1 mm and 7 mm, preferably about 5 mm.

[0119] The Venturi element may include a central axial tube having an outer diameter relatively smaller than the diameter of the central portion. The central axial tube may begin at a beginning of the inlet portion, looking from an upstream end of the Venturi element toward a downstream end of the Venturi element. The central axial tube may extend through the entire length of the Venturi element. The central axial tube may extend through the inlet portion, the central portion, and the outlet portion. The central axial tube may end at an end of the central portion, looking from the upstream end toward the downstream end. The central axial tube may begin at the central portion and end at an end of the outlet portion. The central axial tube may be elongated. The central axial tube may have a cylindrical shape. The central axial tube is preferably hollow. The central axial tube is preferably disposed along a longitudinal axis of the Venturi element. The central axial tube is preferably disposed such that air can flow through the central axial tube toward the downstream end of the Venturi element. The central axial tube is preferably arranged such that air flows around the central axial tube through the central portion, enters the outlet portion and then exits the venturi element. The central axial tube is preferably arranged such that two flow paths are created, one through the central axial tube and one around the central axial tube. If the central axial tube extends throughout the inlet portion, the central portion and the outlet portion, the air flowing through the central axial tube may be delivered directly to the user's mouth independent of the air flowing around the central axial tube. Alternatively, if the central axial tube terminates at the end of the central portion, the air exiting the central axial tube may merge with the air flowing around the central axial tube at the outlet portion. The central axial tube preferably has a constant diameter. The central axial tube is preferably configured such that the air flowing through the central axial tube flows in a laminar flow.

[0120] The Venturi element may comprise a propeller at or downstream of the outlet portion. The propeller may create a pleasant mouth fullness in the user's mouth. The propeller may have 2 to 6 blades, preferably 3 blades. The propeller pitch may be 1 mm to 10 mm, preferably about 6 mm. The propeller pitch may be defined as the displacement that the propeller creates in a complete 360 ​​degree spin in a virtual solid material. The propeller may be integrally formed with the Venturi element. The propeller may be provided as a separate element connectable with the Venturi element. The outlet portion may include attachment means for attaching the propeller to the outlet portion. The attachment means may be provided by a groove for a nut. The propeller may be attached to the outlet portion by a snap-fit ​​connection. The propeller may be made from the same material as the Venturi element. The central axis of the propeller may be aligned along the longitudinal axis of the Venturi element.

[0121] A propeller may be combined with the central axial tube described above. In this embodiment, the central axial tube preferably starts at the central portion when viewed from the upstream direction toward the downstream direction. The central axial tube preferably extends all the way to the end of the outlet portion so that air flowing through the central axial tube can exit the central axial tube and flow directly into the user's mouth. In this embodiment, the propeller may be disposed around the central axial tube, preferably adjacent the downstream end of the outlet portion. The propeller may optimize the airflow of the air flowing around the central axial tube. The propeller may be disposed fixed or freely rotatable.

[0122] The Venturi element may comprise a vent. The vent may be disposed in one or more of the inlet portion, the central portion and the outlet portion. A plurality of vents may be provided. The vent may create a fluid connection between the outside of the Venturi element and the respective portion of the Venturi element in which the vent is disposed. The vent is preferably disposed in the central portion. This arrangement may have the advantage that air may be drawn from the outside of the Venturi element into the central portion, where it may mix with the airflow through the Venturi element. Air may be drawn from the outside of the Venturi element into the central portion, since the air pressure in the central portion may be lower than the air pressure outside the Venturi element due to the Venturi effect. The mixture of outside air and the airflow from the substrate portion of the aerosol-generating article may generate an optimized aerosol.

[0123] The Venturi element may include a second airflow channel parallel to the first airflow channel. The Venturi element may include a second inlet portion, a second central portion, and a second outlet portion. The second inlet portion may be configured to converge toward the second central portion, and the second outlet portion may be configured to diverge from the second central portion.

[0124] The second inlet portion, the second central portion, and the second outlet portion may form a second airflow channel. The second airflow channel may be arranged parallel to the first airflow channel. The first and second airflow channels may be arranged parallel to the longitudinal axis of the Venturi element. The air flowing through the first airflow channel may merge with the air flowing through the second airflow channel at or behind the downstream end of the Venturi element. The air drawn from the base portion or the filter portion of the aerosol-generating article and entering the Venturi element may be divided between the first airflow channel and the second airflow channel. With respect to the dimensions of the second airflow channel, the second airflow channel may be configured in a similar but inverted configuration as described above to the first airflow channel. In other words, the second airflow channel may have a shape that is inverse to the first airflow channel.

[0125] When two airflow channels are provided, a common upstream portion may be provided for splitting the airflow between the inlet portion of the first airflow channel and the inlet portion of the second airflow channel. The common upstream portion may be disposed between the base portion or filter portion of the aerosol-generating article and the airflow channel. The common upstream portion may be disposed within the Venturi element. By providing two airflow channels, an optimized resistance to withdrawal (RTD) may be achieved. In some embodiments, the preferred optimized resistance to withdrawal of the Venturi element alone may be between 5 mmWG and 60 mmWG, preferably between 5 mmWG and 30 mmWG, more preferably between 10 mmWG and 15 mmWG. In some embodiments, the preferred optimized resistance to withdrawal of the Venturi element alone may be approximately 12 mmWG. In some embodiments, the optimized resistance to withdrawal of both the device and the consumable may be between 50 mmWG and 60 mmWG, preferably between 52 mmWG and 56 mmWG. By providing two airflow channels, a greater sense of mouth fullness may be achieved. The delivery profile of the sensory experience and the usage experience may be adjusted by adjustment of the structure of the two airflow channels.

[0126] When the aerosol-generating article comprises a non-liquid aerosol-forming substrate, the inlet portion of the second airflow channel may converge towards a central portion of the second airflow channel at an inlet angle of 2 degrees to 10 degrees, preferably 4 degrees to 8 degrees, more preferably 6 degrees. The axial length of the inlet portion may be 14 mm to 35 mm, preferably 19 mm to 28 mm, more preferably 23 mm. The axial length of the central portion may be 2 mm to 5 mm, preferably 3 mm to 4 mm, more preferably 3.2 mm. The central portion of the second airflow channel may have an axial length of about 1.6 mm. The outlet portion of the second airflow channel may be configured to diverge from the central portion of the Venturi element at an outlet angle of 16 degrees to 20 degrees, preferably 17 degrees to 19 degrees, more preferably 18 degrees. The axial length of the outlet portion may be 3 mm to 10 mm, preferably 5 mm to 9 mm, more preferably 7.7 mm.

[0127] When the aerosol-generating article comprises a liquid aerosol-forming substrate, the inlet portion of the second airflow channel may converge towards a central portion of the second airflow channel at an inlet angle of 16° to 20°, preferably 17° to 19°, more preferably 18°. The axial length of the inlet portion may be 3mm to 10mm, preferably 5mm to 9mm, more preferably 7mm. The axial length of the central portion may be 2mm to 5mm, preferably 3mm to 4mm, more preferably 3.2mm. The central portion of the second airflow channel may have an axial length of about 1.6mm. The outlet portion of the second airflow channel may be configured to diverge from the central portion of the Venturi element at an outlet angle of 2° to 10°, preferably 4° to 8°, more preferably 6°. The axial length of the outlet portion may be 14mm to 35mm, preferably 19mm to 28mm, more preferably 23mm.

[0128] A venturi element including two airflow channels having the above-described configuration may be used as a universal venturi element. The universal venturi element may be used in aerosol-generating articles including non-liquid aerosol-forming substrates. The universal venturi element may be used in aerosol-generating articles including liquid aerosol-forming substrates.

[0129] In a Venturi element comprising two airflow channels having the above-mentioned configuration, each of the airflow channels may be configured to be closable. The airflow channels may be configured to be independently closable. Closure of an airflow channel may prevent airflow through the channel. Closure of one of the airflow channels may be facilitated manually. Closure of one of the airflow channels may be facilitated automatically. A detector may be provided to detect the type of aerosol-forming substrate. When using an aerosol-generating article comprising a non-liquid aerosol-forming substrate, an airflow channel having an inlet angle smaller than the above-mentioned outlet angle may be used and the other airflow channel may be closed, or vice versa.

[0130] A universal Venturi element may be used in an aerosol-generating article that includes a liquid aerosol-forming substrate and a non-liquid aerosol-forming substrate, where each airflow channel is open, in which case the liquid and non-liquid aerosol-forming substrates can be heated in parallel.

[0131] The present invention may further relate to a Venturi element for use in an aerosol-generating article comprising an aerosol-forming substrate. The Venturi element may comprise an airflow channel. The airflow channel may comprise an inlet portion, a central portion, and an outlet portion. The inlet portion is configured to converge towards the central portion and the outlet portion is configured to diverge from the central portion.

[0132] The axial length of the central portion may be between 2 mm and 5 mm, preferably between 3 mm and 4 mm, more preferably 3.2 mm. It is particularly preferred that the central portion is constituted by a transition between the inlet portion and the outlet portion. The central portion may not have a substantial length.

[0133] The inner diameter of the central portion may be from 0.5 mm to 1.5 mm, preferably from 0.8 mm to 1.2 mm, and more preferably 1 mm.

[0134] The inlet portion may be configured to converge towards the central portion at an inlet angle of 16 degrees to 20 degrees, preferably 17 degrees to 19 degrees, more preferably 18 degrees. This inlet angle is particularly preferred when a non-liquid aerosol-forming substrate is used.

[0135] The exit portion may be configured to diverge from the central portion at an exit angle of between 2 degrees and 10 degrees, preferably between 4 degrees and 8 degrees, more preferably 6 degrees. This exit angle is particularly preferred when a non-liquid aerosol-forming substrate is used.

[0136] When using an aerosol-generating article having a non-liquid aerosol-forming substrate, the axial length of the inlet portion may be from 3mm to 10mm, preferably from 5mm to 9mm, more preferably 7.7mm.

[0137] When using an aerosol-generating article having a non-liquid aerosol-forming substrate, the axial length of the outlet portion may be from 14mm to 35mm, preferably from 19mm to 28mm, more preferably 23mm.

[0138] In the case of an aerosol-generating article comprising a liquid aerosol-forming substrate, the inlet portion may be configured to converge towards the central portion at an inlet angle of between 2 degrees and 10 degrees, preferably between 4 degrees and 8 degrees, more preferably 6 degrees.

[0139] When using an aerosol-generating article having a liquid aerosol-forming substrate, the outlet portion may be configured to diverge from the central portion at an outlet angle of 16 degrees to 20 degrees, preferably 17 degrees to 19 degrees, more preferably 18 degrees.

[0140] When using an aerosol-generating article having a liquid aerosol-forming substrate, the axial length of the inlet portion may be from 14mm to 35mm, preferably from 19mm to 28mm, more preferably 23mm.

[0141] When using an aerosol-generating article having a liquid aerosol-forming substrate, the axial length of the outlet portion may be from 3mm to 10mm, preferably from 5mm to 9mm, more preferably 7.7mm.

[0142] The outlet section may include a screw thread. Preferably, the screw may include a helical screw thread. The screw thread may be configured to generate a swirling airflow. The screw thread may generate a vortex. The screw thread may be disposed on an inner wall of the outlet section. The screw thread may be disposed along an entire length of the outlet section. The screw thread may be disposed along a portion of the outlet section, preferably adjacent a downstream end of the outlet section. The pitch of the screw thread may be between 1 mm and 7 mm, preferably about 5 mm.

[0143] The Venturi element may include a central axial tube having an outer diameter relatively smaller than the diameter of the central portion. The central axial tube may begin at a beginning of the inlet portion, looking from an upstream end of the Venturi element toward a downstream end of the Venturi element. The central axial tube may extend through the entire length of the Venturi element. The central axial tube may extend through the inlet portion, the central portion, and the outlet portion. The central axial tube may end at an end of the central portion, looking from the upstream end toward the downstream end. The central axial tube may begin at the central portion and end at an end of the outlet portion. The central axial tube may be elongated. The central axial tube may have a cylindrical shape. The central axial tube is preferably hollow. The central axial tube is preferably disposed along a longitudinal axis of the Venturi element. The central axial tube is preferably disposed such that air can flow through the central axial tube toward the downstream end of the Venturi element. The central axial tube is preferably arranged such that air flows around the central axial tube through the central portion, enters the outlet portion and then exits the venturi element. The central axial tube is preferably arranged such that two flow paths are created, one through the central axial tube and one around the central axial tube. If the central axial tube extends throughout the inlet portion, the central portion and the outlet portion, the air flowing through the central axial tube may be delivered directly to the user's mouth independent of the air flowing around the central axial tube. Alternatively, if the central axial tube terminates at the end of the central portion, the air exiting the central axial tube may merge with the air flowing around the central axial tube at the outlet portion. The central axial tube preferably has a constant diameter. The central axial tube is preferably configured such that the air flowing through the central axial tube flows in a laminar flow.

[0144] The Venturi element may comprise a propeller at or downstream of the outlet portion. The propeller may generate a pleasant fullness in the user's mouth. The propeller may have 2 to 6 blades, preferably 3 blades. The propeller pitch may be 1 mm to 10 mm, preferably about 6 mm. The propeller pitch may be defined as the displacement that the propeller produces in a complete 360 ​​degree spin in a virtual solid material. The propeller may be integrally formed with the Venturi element. The propeller may be provided as a separate element connectable with the Venturi element. The outlet portion may include attachment means for attaching the propeller to the outlet portion. The attachment means may be provided by a groove for a nut. The propeller may be attached to the outlet portion by a snap-fit ​​connection. The propeller may be made from the same material as the Venturi element. The central axis of the propeller may be aligned along the longitudinal axis of the Venturi element.

[0145] A propeller may be combined with the central axial tube described above. In this embodiment, the central axial tube preferably starts at the central portion when viewed from the upstream direction toward the downstream direction. The central axial tube preferably extends all the way to the end of the outlet portion so that air flowing through the central axial tube can exit the central axial tube and flow directly into the user's mouth. In this embodiment, the propeller may be disposed around the central axial tube, preferably adjacent the downstream end of the outlet portion. The propeller may optimize the airflow of the air flowing around the central axial tube. The propeller may be disposed fixed or freely rotatable.

[0146] The Venturi element may comprise a vent. The vent may be arranged in one or more of the inlet portion, the central portion and the outlet portion. A plurality of vents may be provided. The vent may create a fluid connection between the outside of the Venturi element and the respective portion of the Venturi element in which the vent is arranged. The vent is preferably arranged in the central portion. This arrangement may have the advantage that air may be drawn from the outside of the Venturi element into the central portion, where it may mix with the airflow through the Venturi element. Air may be drawn from the outside of the Venturi element into the central portion, since the air pressure in the central portion may be lower than the air pressure outside the Venturi element due to the Venturi effect. The mixture of outside air and the airflow along the longitudinal axis of the Venturi element may create an optimized aerosol.

[0147] The Venturi element may include a second airflow channel parallel to the first airflow channel. The Venturi element may include a second inlet portion, a second central portion, and a second outlet portion. The second inlet portion may be configured to converge toward the second central portion, and the second outlet portion may be configured to diverge from the second central portion.

[0148] The second inlet portion, the second central portion, and the second outlet portion may form a second airflow channel. The second airflow channel may be disposed parallel to the first airflow channel. The first and second airflow channels may be disposed parallel to the longitudinal axis of the Venturi element. The air flowing through the first airflow channel may merge with the air flowing through the second airflow channel at or behind the downstream end of the Venturi element. The air entering the Venturi element may be split between the first airflow channel and the second airflow channel. With respect to the dimensions of the second airflow channel, the second airflow channel may be configured similar to the first airflow channel as described above, but in an inverted configuration. In other words, the second airflow channel may have an inverted shape to the first airflow channel. When the aerosol-generating article includes a non-liquid aerosol-forming substrate, the inlet portion of the second airflow channel may converge toward the central portion of the second airflow channel at an inlet angle of 2 degrees to 10 degrees, preferably 4 degrees to 8 degrees, more preferably 6 degrees. The axial length of the inlet portion may be between 14mm and 35mm, preferably between 19mm and 28mm, more preferably between 23mm. The axial length of the central portion may be between 2mm and 5mm, preferably between 3mm and 4mm, more preferably between 3.2mm. The central portion of the second airflow channel may have an axial length of about 1.6mm. The outlet portion of the second airflow channel may be configured to diverge from the central portion of the Venturi element at an outlet angle of between 16° and 20°, preferably between 17° and 19°, more preferably between 18°. The axial length of the outlet portion may be between 3mm and 10mm, preferably between 5mm and 9mm, more preferably between 7.7mm.

[0149] Where the aerosol-generating article comprises a liquid aerosol-forming substrate, the inlet portion of the second airflow channel may converge towards a central portion of the second airflow channel at an inlet angle of 16 degrees to 20 degrees, preferably an inlet angle of 17 degrees to 19 degrees, more preferably an inlet angle of 18 degrees. The outlet portion of the second airflow channel may be configured to diverge from the central portion of the Venturi element at an outlet angle of 2 degrees to 10 degrees, preferably 4 degrees to 8 degrees, more preferably 6 degrees.

[0150] The axial length of the inlet portion may be 3mm to 10mm, preferably 5mm to 9mm, more preferably 7.7mm. The axial length of the central portion may be 2mm to 5mm, preferably 3mm to 4mm, more preferably 3.2mm. The central portion of the second airflow channel may have an axial length of about 1.6mm. The axial length of the outlet portion may be 14mm to 35mm, preferably 19mm to 28mm, more preferably 23mm.

[0151] When two airflow channels are provided, a common upstream portion may be provided for splitting the airflow between the inlet portion of the first airflow channel and the inlet portion of the second airflow channel. The common upstream portion may be disposed within a Venturi element. By providing two airflow channels, an optimized resistance to withdrawal (RTD) may be achieved. In some embodiments, the preferred optimized resistance to withdrawal of the Venturi element alone may be between 5mmWG and 60mmWG, preferably between 5mmWG and 30mmWG, more preferably between 10mmWG and 15mmWG. In some embodiments, the preferred optimized resistance to withdrawal of the Venturi element alone may be approximately 12mmWG. In some embodiments, the optimized resistance to withdrawal of both the device and the consumable may be between 50mmWG and 60mmWG, preferably between 52mmWG and 56mmWG. By providing two airflow channels, a greater sense of mouth fullness may be achieved. The delivery profile of the sensory experience and the usage experience may be adjusted by adjustment of the structure of the two airflow channels.

[0152] The present invention further relates to a kit of Venturi elements for use in the aerosol generating systems described herein, each Venturi element configured for removably attachment to one or both of the aerosol generating articles described herein and the aerosol generating devices described herein, each Venturi element configured with different properties.

[0153] The different properties may be achieved by the structural configuration of the Venturi elements. Each of the Venturi elements of the kit of Venturi elements may be configured as described herein, and in particular includes an inlet portion, a central portion, and an outlet portion as described herein.

[0154] The term "characteristics" may refer to one or more of the physical characteristics of the Venturi element and the mechanical characteristics of the Venturi element. The physical characteristics may be velocity or pressure. Different velocities or pressures, preferably pressure changes, may promote different aerosol flows and different spatial distances of vapor paths. The mechanical characteristics may be the dimensions, materials, and / or designs of the Venturi element. The different dimensions of the Venturi element may be configured by different lengths of one or more of the inlet, middle, and outlet sections. The different dimensions of the Venturi element may be configured by different angles of one or more of the inlet and outlet sections. The different characteristics may result from different configurations of the airflow channels of the individual Venturi elements, preferably of the inlet and outlet sections, more preferably of the inlet and outlet angles. The different materials of the Venturi element may have different friction coefficients. The different friction coefficients may promote different aerosol flow rates. The different designs of the Venturi element may be a dual Venturi element, or a propeller within the Venturi element, or one or more of the designs described herein.

[0155] Different characteristics of the Venturi elements may promote different aerosol generation. The characteristics may define the usage experience. The exit angle of each of the Venturi elements may differ by at least 0.5 degrees, preferably at least 1 degree, more preferably at least 2 degrees, and most preferably 2 degrees. In this case, the kit of Venturi elements may be configured for use with one or more aerosol-generating articles including an aerosol-forming substrate, preferably a non-liquid aerosol-forming substrate.

[0156] The inlet angles of each of the Venturi elements may differ by at least 0.5 degrees, preferably at least 1 degree, more preferably at least 2 degrees, and most preferably 2 degrees. In this case, the kit of Venturi elements may be configured for use with one or more aerosol-generating articles including an aerosol-forming substrate, preferably a liquid aerosol-forming substrate.

[0157] In some embodiments, a kit of Venturi elements may be configured for use with a variety of aerosol-forming substrates, for example, one or more Venturi elements in the kit may be configured for use with a liquid aerosol-forming substrate and another one or more Venturi elements in the kit may be configured for use with a non-liquid aerosol-forming substrate.

[0158] One or more of the venturi elements in the kit may include one or more different options. One option is that the venturi element may include a thread at the outlet portion. A further option is that the venturi element includes a central axial tube having an outer diameter relatively smaller than the diameter of the central portion. Another option is that the venturi element includes a propeller at or downstream of the outlet portion, or a vent in the venturi element. The venturi element may further optionally include a second airflow channel parallel to the first airflow channel. Thus, the venturi element may include a second inlet portion, a second central portion, and a second outlet portion, where the second inlet portion may be configured to converge toward the second central portion, and the second outlet portion may be configured to diverge from the second central portion.

[0159] In the kit of Venturi elements, at least one Venturi element includes at least one of the above options and at least one different Venturi element includes a different at least one of the above options.

[0160] For example, one venturi element of the kit of venturi elements may include a thread at the outlet portion and another venturi element of the kit of venturi elements may include a propeller at or downstream of the outlet portion.

[0161] Different options and different configurations of the Venturi elements of the kit of Venturi elements, especially different inlet and outlet angles, may result in different usage experiences. A user may select his / her desired usage experience by selecting a corresponding Venturi element from the kit of Venturi elements. The selected Venturi element may then be attached by the user to the aerosol-generating article. The Venturi elements of the kit of Venturi elements may be provided with different markers corresponding to different usage experiences. The markers may be tactile or optical markers. The tactile markers may be markers with a specific surface structure. The optical markers may be colored markers. Individual markets may correspond to specific usage experiences, such as a light usage experience or a strong usage experience. The markers may be provided with different colors or different surface structures, or a combination thereof, to allow identification of the markers.

[0162] The kit of Venturi elements may be contained in a package containing different Venturi elements. The package of Venturi elements may include a marker as described above, e.g., a tactile marker or an optical marker, to allow identification of the enclosed Venturi element.

[0163] A kit of Venturi elements for an aerosol-generating article comprising a non-liquid aerosol-forming substrate may differ from a kit of Venturi elements for an aerosol-generating article comprising a liquid aerosol-forming substrate, for example the Venturi elements of an aerosol-generating article comprising a non-liquid aerosol-forming substrate may differ from the Venturi elements of an aerosol-generating article comprising a liquid aerosol-forming substrate by a different marker.

[0164] The invention may further relate to a method of manufacturing a Venturi element for use in an aerosol-generating article comprising an aerosol-forming substrate, the method comprising: i. providing a venturi element comprising an airflow channel, the airflow channel may comprise an inlet portion, a central portion, and an outlet portion, the inlet portion configured to converge towards the central portion and the outlet portion configured to diverge from the central portion. If the aerosol-generating article comprises a non-liquid aerosol-forming substrate, the inlet portion may be configured to converge towards the central portion at an inlet angle of 16 degrees to 20 degrees, preferably 17 degrees to 19 degrees, more preferably 18 degrees. If the aerosol-generating article comprises a liquid aerosol-forming substrate, the inlet portion may be configured to converge towards the central portion at an inlet angle of 2 degrees to 10 degrees, preferably 4 degrees to 8 degrees, more preferably 6 degrees.

[0165] The method may include attaching a Venturi element to the aerosol-generating article. If the aerosol-generating article includes a hollow filter portion, the method may include inserting the Venturi element into the hollow filter portion of the aerosol-generating article. The Venturi element may include a connecting element. The method may include inserting the Venturi element into the hollow filter portion of the aerosol-generating article. The method may include providing any of the elements and Venturi element configurations described above.

[0166] Features described with respect to one aspect may be equally applied to other aspects of the invention.

[0167] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0168] [Figure 1] FIG. 1 shows a system comprising an aerosol-generating article and a venturi element, where the aerosol-generating article and the venturi element are permanently fixed to each other. [Diagram 2]FIG. 2 illustrates an embodiment in which the aerosol-generating article and the venturi element are configured to be detachable by a connecting portion of the aerosol-generating article and a connecting element of the venturi element. [Diagram 3] FIG. 3 shows a cross-sectional view of a Venturi element. [Figure 4] FIG. 4 shows an aerosol generating device with a mouthpiece having a Venturi element. [Diagram 5] FIG. 5 shows an exploded view of the aerosol generating device of FIG. [Figure 6] FIG. 6 shows an embodiment of a Venturi element having a thread at the outlet portion. [Figure 7] FIG. 7 shows two embodiments of a Venturi element having a central axial tube. [Figure 8] FIG. 8 shows various views of an embodiment of a venturi element having a propeller. [Figure 9] FIG. 9 shows an embodiment of a Venturi element having a central axial tube and propeller combination. [Figure 10] FIG. 10 illustrates various embodiments of a venturi element having vent holes at various different locations along the venturi element. [Figure 11] FIG. 11 shows an embodiment of a Venturi element having two airflow channels. [Figure 12] FIG. 12 shows an embodiment of a Venturi element having a central section of negligible length. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0169] Figure 1 shows an aerosol-generating article 10 as well as a venturi element 12. The aerosol-generating article 10 comprises a base portion 14 and a filter portion 16. The filter portion 16 is preferably configured as a hollow acetate tube. Figure 1 shows the venturi element 12 attached to the aerosol-generating article 10. The venturi element 12 is preferably permanently attached to the aerosol-generating article 10, more precisely to the filter portion 16 of the aerosol-generating article 10, in the embodiment shown in Figure 1. An outer wrapper may be provided surrounding the aerosol-generating article 10 and the venturi element 12.

[0170] 2 shows an embodiment in which the Venturi element 12 is configured to be removably attachable to the aerosol-generating article 10. The filter portion 16 of the aerosol-generating article 10 includes a connecting portion 18 for connecting the Venturi element 12 to the aerosol-generating article 10. The connecting portion 18 of the aerosol-generating article 10 may also be a filter, preferably a hollow acetate tube. Alternatively, the connecting portion 18 of the aerosol-generating article 10 may be provided in addition to the filter portion 16. The filter portion 16 may be disposed between the base portion 14 and the connecting portion 18.

[0171] The Venturi element 12 shown in FIG. 2 includes a connecting element 20 for insertion into the connecting portion 18 of the aerosol-generating article 10. The connecting element 20 of the Venturi element 12 preferably has a tapered shape. A step 22 surrounds the outer periphery of the connecting element 20. The tapered configuration of the connecting element 20 allows for easy insertion of the connecting element 20 of the Venturi element 12 into the connecting portion 18 of the aerosol-generating article 10. The step 22 surrounding the outer periphery of the connecting element 20 of the Venturi element 12 is configured to hold the connecting element 20 securely inside the connecting portion 18 of the aerosol-generating article 10. The connecting portion 18 of the aerosol-generating article 10 is preferably configured to be hollow so that the connecting element 20 of the Venturi element 12 can be easily inserted into the hollow connecting portion 18. The upstream end 24 of the connecting element 20 of the Venturi element 12 preferably has an outer diameter smaller than the inner diameter of the hollow connecting portion 18 of the aerosol-generating article 10. The upstream end 24 of the connecting element 20 may be the upstream end 24 of the Venturi element 12. As seen in FIG. 2, the connecting element 20 of the Venturi element 12 is tapered such that the outer diameter of the connecting element 20 of the Venturi element 12 increases toward the downstream end. The maximum outer diameter of the connecting element 20 of the Venturi element 12 is preferably greater than the inner diameter of the hollow connecting portion 18 of the aerosol-generating article 10. Thus, the connecting element 20 of the Venturi element 12 is securely held within the hollow connecting portion 18 of the aerosol-generating article 10 after the connecting element 20 is inserted into the connecting portion 18. The holding of the connecting element 20 of the Venturi element 12 may be further assisted by step 22. The inner wall of the hollow connecting portion 18 of the aerosol-generating article 10 may include an element not shown in FIG. 2 that may interface with the step 22 of the connecting element 20 of the Venturi element 12.

[0172] FIG. 3 shows a cross-sectional view of the Venturi element 12. The Venturi element 12 includes an inlet portion 26, a central portion 28, and an outlet portion 30. The inlet portion 26 tapers toward the central portion 28. In FIG. 3, the inlet portion 26 has a conical shape. The inner diameter of the inlet portion 26 decreases from the upstream end of the Venturi element toward the downstream end of the Venturi element. The central portion 28 forms a narrowed airflow passage for air flowing through the Venturi element 12. The axial length L of the central portion 28 is central The diameter of the inlet portion 26 may be between 2 mm and 5 mm, preferably 3.2 mm. The central portion 28 has a constant inner diameter, preferably 2 mm. Disposed downstream of the central portion 28 is an outlet portion 30. The outlet portion 30 diverges from the central portion 28 towards a downstream end 32 of the venturi element 12. The outlet portion 30 also has a conical shape, but is oriented in the opposite direction compared to the inlet portion 26.

[0173] When the aerosol-generating article comprises an aerosol-forming substrate, preferably a non-liquid aerosol-forming substrate, the inlet angle α of the inlet section 26 may be between 16 degrees and 20 degrees, preferably between 17 degrees and 19 degrees, more preferably 18 degrees. The inlet angle is the angle between the longitudinal axis of the inlet section and the inner wall of the inlet section. The axial length L of the inlet section 26 is inlet The thickness may be 3 mm to 10 mm, preferably 7.7 mm.

[0174] The outlet section 30 may have an outlet angle θ between 2 degrees and 10 degrees, preferably between 4 degrees and 8 degrees, and more preferably 6 degrees. The outlet angle is the angle between the longitudinal axis of the outlet section and the inner wall of the outlet section. The axial length L of the outlet section 30 outlet The maximum inner diameter of the outlet portion 30 at the downstream end 32 may be, for example, 6 mm.

[0175] When the aerosol-generating article comprises a liquid aerosol-forming substrate, the dimensions and angle of the Venturi element are different from when the aerosol-generating article comprises a non-liquid aerosol-forming substrate. In this case, the inlet angle α of the inlet section 26 may preferably be between 2 degrees and 10 degrees, preferably between 4 degrees and 8 degrees, more preferably 6 degrees. The axial length L of the inlet section 26 may be inlet The maximum inner diameter of the inlet portion 26 may be, for example, 3 mm. The maximum inner diameter of the outlet portion 30 at the downstream 32 may be, for example, 3 mm. The outlet angle θ is, for example, 16 degrees to 20 degrees, preferably 18 degrees. The axial length L of the outlet portion 30 outlet The thickness may be 3 mm to 10 mm, preferably 7.7 mm.

[0176] The inlet portion 26, the central portion 28, and the outlet portion 30 together form an airflow channel in the Venturi element 12 from the upstream end 24 of the Venturi element 12 to the downstream end 32 of the Venturi element 12. The downstream end 32 of the Venturi element 12 is configured for a user to capture the downstream end 32 of the Venturi element 12 between the lips of the user for inhalation of the aerosol formed at the outlet portion 30 of the Venturi element 12. The Venturi element may have a shape adapted to hold the downstream end 32 of the Venturi element 12 between the lips of the user, e.g., a comfortable ergonomic shape. Air containing vaporized aerosol-forming substrate from the aerosol-generating article 10 may flow into the inlet portion 26 of the Venturi element 12. The air is then compressed in the central portion 28, thereby reducing the pressure and increasing the velocity of the air. As the air is drawn from the central portion 28 into the outlet portion 30, the air expands and cools, such that optimized droplets may be formed in the aerosol. The aerosol can then be inhaled by the user.

[0177] 4 shows an aerosol generating device in which the Venturi element 12 may be incorporated. The Venturi element 12 may preferably be part of the mouthpiece 34 of the aerosol generating device. The aerosol generating device comprises further elements such as a heating chamber 36 in or around which a heating element may be provided. The heating element may be powered by a power source 38. The supply of electrical energy from the power source 38 to the heater element may be controlled by an electrical circuit 40.

[0178] FIG. 5 shows the aerosol generating device of FIG. 4 in an exploded view. The Venturi element 12 is shown disposed along the longitudinal axis of the aerosol generating device. The aerosol generating device may comprise two major components of the aerosol generating device: a mouthpiece 34 and a body 42. The mouthpiece 34 may include the Venturi element 12, and the body 42 may include further components such as a power source 38 and an electrical circuit 40. The heating chamber 36 may be formed partially in the mouthpiece 34 and the body 42, or in each of these major components. The mouthpiece 34 and the body 42 may be configured to be detachable from each other. In the detached state, the aerosol generating article 10 may be inserted into the heating chamber 36. The mouthpiece 34 may be attached to the body 42 such that the aerosol generating article 10 is surrounded or at least partially surrounded or enclosed within the heating chamber 36 by the mouthpiece 34 and the body 42. The Venturi element 12 may then be disposed downstream of the aerosol generating article 10. The body 42 of the aerosol generating device may include one or more air inlets 44 that allow ambient air to enter the aerosol generating device. The air inlets 44 are best seen in FIG. 4. Air may flow through the one or more air inlets 44 into the heating chamber 36 where heating of the air and of the aerosol-forming substrate contained in the aerosol-generating article 10 takes place. The vaporized aerosol-forming substrate may be entrained in the air flowing through the heating chamber 36. The air containing the vaporized aerosol-forming substrate then flows through the Venturi element 12. The aerosol may then be inhaled by a user downstream of the Venturi element 12.

[0179] 6 illustrates an embodiment of the Venturi element 12 in which the outlet portion 30 of the Venturi element 12 has threads 46. The threads 46 are preferably configured as helical threads 46. The pitch 48 of the threads 46 is shown in FIG. 6 and is preferably about 5 mm. The threads 46 create a swirling airflow at the outlet portion 30, as shown in the lower portion of FIG. 6. This may create a comfortable usage experience for a user inhaling the swirling aerosol at the downstream end 32 of the Venturi element 12.

[0180] FIG. 7 shows an embodiment in which a central axial tube 50 is provided along the longitudinal axis of the Venturi element 12. The central axial tube 50 provides a second airflow path. Air flows in a laminar flow through the central axial tube 50 toward the user's mouth. In addition to this central airflow through the central axial tube 50, air can flow around the central axial tube 50 for aerosol generation. The air flowing around the central axial tube 50 can flow turbulently. The air flowing around the central axial tube 50 passes through the constricted portion of the central portion 28 into the outlet portion 30, where the air can expand. Thus, optimized droplets can be generated in the outlet portion 30 around the central axial tube 50 and merge with the aerosol flowing downstream of the Venturi element 12 through the central axial tube 50 into the user's mouth. This arrangement can provide a comfortable sensory experience for the user. The top of FIG. 7 shows an embodiment in which the central axial tube 50 extends the entire length of the Venturi element 12. 7 shows an embodiment in which the central axial tube 50 extends through the inlet portion 26 and the central portion 28 of the Venturi element 12, but does not extend through the outlet portion 30. In another embodiment, not shown, the central axial tube 50 may extend only through the outlet portion 30. In another embodiment, the central axial tube 50 may extend only through the central portion 28 and the outlet portion 30, but not through the inlet portion 26.

[0181] Figure 8 shows a configuration in which a propeller 52 is provided at the outlet portion 30 of the Venturi element 12. The propeller 52 generates a swirling aerosol airflow downstream of the Venturi element 12 and into the user's mouth. The propeller 52 is therefore disposed adjacent the downstream end 32 of the Venturi element 12. The propeller 52 may include multiple blades. An embodiment having three or four blades is shown at the bottom of Figure 8. Although a configuration having three blades is particularly preferred, it will be understood that three or even more than four blades may be used within the scope of the present invention.

[0182] Figure 9 shows an embodiment in which the embodiments of Figures 7 and 8 are combined. More specifically, a central axial tube 50 is provided with a propeller 52 surrounding the central axial tube 50. The propeller 52 is disposed adjacent to the downstream end 32 of the venturi element 12. Optimized droplets are generated around the central axial tube 50 and the outlet portion 30 of the venturi element 12, and the aerosol airflow is further optimized by the propeller 52. This airflow merges with the air entering the user's mouth from the central axial tube 50 for a comfortable use experience.

[0183] FIG. 10 illustrates an embodiment in which a vent hole 54 is provided. The top of FIG. 10 illustrates an embodiment in which the vent hole 54 is provided in the inlet portion 26 of the Venturi element 12. In all of the embodiments illustrated in FIG. 10, the vent hole 54 allows air to flow from outside the Venturi element 12 through the Venturi element 12 into the airflow channel. The center of FIG. 10 illustrates an embodiment in which the vent hole 54 is disposed in the center portion 28, and the bottom of FIG. 10 illustrates an embodiment in which the vent hole 54 is disposed in the outlet portion 30 of the Venturi element 12. The center of FIG. 10 illustrates a preferred embodiment because the air pressure in the center portion 28 of the Venturi element 12 is reduced as air flows through the Venturi element 12. In this regard, the Venturi effect results in a reduction in pressure and an increase in velocity in the center portion 28 of the Venturi element 12 because this center portion 28 is a constricted airflow passage compared to the inlet portion 26 and the outlet portion 30 of the Venturi element 12. Thus, air may be drawn from outside the Venturi element 12 into the central portion 28 through the vents 54. This outside air may then merge with air flowing through the Venturi element 12 from the upstream end 24 of the Venturi element 12 toward the downstream end 32 of the Venturi element 12. This may result in a comfortable usage experience.

[0184] FIG. 11 shows an embodiment of a Venturi element 12 having two airflow channels. The airflow channel shown in the right part of the embodiment shown in FIG. 11 essentially corresponds to the airflow channel described above with respect to the Venturi element 12 used in conjunction with an aerosol-generating article comprising an aerosol-forming substrate, preferably a non-liquid aerosol-forming substrate. In this airflow channel, the inlet portion 26 is relatively short compared to the outlet portion 30. In this airflow channel, the inlet angle α is relatively larger than the outlet angle θ. In addition to this airflow channel, the second airflow channel provided to the left of the first airflow channel in the embodiment shown in FIG. 11 has an inverted configuration. This means that the second airflow channel essentially corresponds to the first airflow channel when the first airflow channel is arranged in an inverted manner. In this inverted airflow channel, the outlet portion 30 is relatively short compared to the inlet portion 36. In this inverted airflow channel, the inlet angle α is relatively smaller than the outlet angle θ. The airflow channel shown in the left part of the embodiment shown in FIG. 11 essentially corresponds to the airflow channel described above with respect to the Venturi element 12 used in conjunction with an aerosol-generating article comprising a liquid aerosol-forming substrate. In this airflow channel, the inlet portion 26 is relatively large compared to the outlet portion 30. In this airflow channel, the inlet angle α is relatively smaller than the outlet angle θ. In addition to this airflow channel, the second airflow channel provided to the right of the first airflow channel in the embodiment shown in FIG. 11 has an inverted configuration. This means that the second airflow channel essentially corresponds to the first airflow channel when the first airflow channel is arranged in an inverted manner. In this inverted airflow channel, the outlet portion 30 is relatively large compared to the inlet portion 36. In this inverted airflow channel, the inlet angle α is relatively larger than the outlet angle θ. This arrangement of the airflow channels may generate an optimized usage experience, since the two airflow channels may generate slightly different experiences. One of the airflow channels may generate a smooth usage experience and the other airflow channel may generate a pungent or strong delivery profile. In combination, a desired delivery profile may be combined with a smooth usage experience. A common upstream portion 56 may be provided within the Venturi element 12 to distribute air between the first and second airflow channels.

[0185] Figure 12 illustrates a preferred embodiment in which a central portion 28 is configured as a transition between the inlet portion 26 and the outlet portion 30. The central portion 28 of the embodiment illustrated in Figure 12 defines a constricted airflow passage, thus creating a Venturi effect as air flows from the inlet portion 26 to the outlet portion 28.

Claims

1. 1. An aerosol generation system comprising: an aerosol-forming substrate comprising a non-liquid aerosol-forming substrate; a Venturi element; the venturi element includes an airflow channel, the airflow channel including an inlet portion, a central portion, and an outlet portion, the inlet portion configured to converge toward the central portion, the outlet portion configured to diverge from the central portion, the central portion including a narrowed airflow passage; 1. An aerosol generation system, comprising: an inlet portion configured to converge toward the central portion at an inlet angle of 1 degree to 19 degrees; an outlet portion diverging from the central portion at an outlet angle of 2 degrees to 10 degrees; and the outlet portion comprising a screw thread configured to generate a swirling airflow.

2. 2. The aerosol generating system of claim 1, comprising an aerosol-generating article comprising the aerosol-forming substrate.

3. The aerosol generating system of claim 2 , wherein the aerosol generating article comprises the Venturi element.

4. The aerosol generating system of claim 2 , wherein the Venturi element is configured to be removably attachable to the aerosol generating article.

5. 5. The aerosol generating system of claim 4, wherein the aerosol generating article includes a connecting portion, the Venturi element includes an airflow channel including an inlet portion, the inlet portion of the Venturi element includes a connecting element, and the connecting portion of the aerosol generating article is configured to removably receive the connecting element of the Venturi element.

6. 6. The aerosol generating system of claim 5, wherein the connecting portion of the aerosol generating article has a substantially tubular shape configured for insertion of the connecting element of the Venturi element therein.

7. 7. The aerosol generating system of claim 5 or claim 6, wherein the connecting element of the Venturi element comprises a mechanical retention means configured to retain the connecting element of the Venturi element within the connecting portion of the aerosol generating article.

8. 8. The aerosol generating system of claim 1, wherein the Venturi element is configured as a mouthpiece.

9. 8. The aerosol generating system according to claim 2, wherein the aerosol generating article is configured in a rod shape, and a wrapping material is arranged to wrap the aerosol generating article.

10. 10. The aerosol generating system of claim 9, wherein the wrapping material is wrapping paper.

11. 11. The aerosol generation system of claim 1, wherein the inlet portion is configured to converge towards the central portion at an inlet angle of between 16 degrees and 19 degrees.

12. 12. The aerosol generation system of claim 11, wherein the inlet portion is configured to converge towards the central portion at an inlet angle of 17 to 19 degrees.

13. 13. The aerosol generating system of claim 12, wherein the outlet portion diverges from the central portion at an outlet angle of between 4 degrees and 8 degrees.

14. The axial length of the inlet portion is 3 mm to 10 mm. The axial length of the outlet portion is 14 mm to 35 mm. The axial length of the central portion is 2 mm to 5 mm.

14. The aerosol generating system of claim 1, wherein the inner diameter of the central portion is one or more of: 0.5 mm to 1.5 mm.

15. The axial length of the inlet portion is 5 mm to 9 mm. The axial length of the outlet portion is 19 mm to 28 mm. The axial length of the central portion is 3 mm to 4 mm.

15. The aerosol generating system of claim 14, wherein the inner diameter of the central portion is one or more of: 0.8 mm to 1.2 mm.

16. 16. An aerosol generating system according to any preceding claim, wherein the non-liquid aerosol-forming substrate is an electrically heated tobacco product (EHTP).

17. 17. The aerosol generating system of claim 16, wherein the electrically heated tobacco product (EHTP) comprises reconstituted tobacco.

18. 1. An aerosol generation system comprising: an aerosol-forming substrate; a Venturi element; the venturi element includes an airflow channel, the airflow channel including an inlet portion, a central portion, and an outlet portion, the inlet portion configured to converge toward the central portion, and the outlet portion configured to diverge from the central portion; 11. The aerosol generation system of claim 1, wherein the inlet portion is configured to converge towards the central portion at an inlet angle of between 2 degrees and 10 degrees.

19. 20. The aerosol generation system of claim 18, wherein the inlet portion is configured to converge towards the central portion at an inlet angle of between 4 degrees and 8 degrees.

20. 20. The aerosol generation system of claim 19, wherein the inlet portion is configured to converge towards the central portion at an inlet angle of 6 degrees.

21. The axial length of the inlet portion is 14 mm to 35 mm. The axial length of the outlet portion is 3 mm to 10 mm. The axial length of the central portion is 2 mm to 5 mm.

21. The aerosol generating system of any one of claims 18 to 20, wherein the inner diameter of the central portion is one or more of: 0.5 mm to 5 mm.

22. The axial length of the inlet portion is 19 mm to 28 mm. The axial length of the outlet portion is 5 mm to 9 mm. The axial length of the central portion is 3 mm to 4 mm.

22. The aerosol generating system of claim 21, wherein the inner diameter of the central portion is one or more of: 0.8 mm to 1.2 mm.

23. the venturi element further includes a central axial tube having an outer diameter relatively smaller than a diameter of the central portion. the venturi element includes a propeller at or downstream of the outlet portion; the venturi element includes a vent hole; and 23. The aerosol generation system of any one of claims 1 to 22, wherein the Venturi element comprises a second airflow channel parallel to the airflow channel, the second airflow channel comprising a second inlet portion, a second central portion, and a second outlet portion, the second inlet portion configured to converge towards the second central portion, and the second outlet portion configured to diverge from the second central portion.

24. 24. The aerosol generation system of claim 23, wherein the central portion and the second central portion of the airflow channel have axial lengths of 2 mm to 5 mm and 1.6 mm, respectively.

25. 8. An aerosol generating system according to any one of claims 1, 2 and 4 to 7, comprising an aerosol generating device including a recess for receiving the aerosol-forming substrate therein, the aerosol generating device being arranged to heat the received aerosol-forming substrate to a temperature at which one or more volatile compounds are released from the aerosol-forming substrate without substantially combusting the aerosol-forming substrate.

26. 26. The aerosol generating system of claim 25, wherein the device includes a heating element, the heating element being disposed so as to at least partially penetrate an inner portion of the aerosol-forming substrate.

27. 27. An aerosol generating system according to claim 25 or claim 26, comprising a heating element, the heating element being arranged to heat at least an outer surface of the aerosol-forming substrate or of an article comprising the aerosol-forming substrate.

28. 28. An aerosol generation system according to any one of claims 25 to 27, wherein the Venturi element is part of the aerosol generation device.

29. 29. An aerosol generating system according to any one of claims 1 to 28 and a kit of venturi elements for use in said aerosol generating system, comprising: The kit includes at least one venturi element and at least one different venturi element, each venturi element having: an aerosol-generating article comprising an aerosol-forming substrate; and configured to be removably attachable to one or both of the aerosol generating devices; each of the venturi elements being configured with different properties in one or both of the physical and mechanical properties of the venturi elements; Each Venturi element is configured with different characteristics with different exit angles, the exit angles of each of the Venturi elements differing by at least 0.5 degrees; and / or each venturi element is configured with different characteristics with a different inlet angle, the inlet angles of each of the venturi elements differing by at least 0.5 degrees; Furthermore, the aerosol-generating article comprising the aerosol-forming substrate; and an aerosol-generating device including a cavity for receiving the aerosol-forming substrate therein, the aerosol-generating device being arranged to heat the received aerosol-forming substrate to a temperature at which one or more volatile compounds are released from the aerosol-forming substrate without substantially combusting the aerosol-forming substrate. The aerosol generation system and a kit of venturi elements for use in the aerosol generation system.

30. the exit angles of each of the Venturi elements differ by at least 1 degree; and / or 30. The aerosol generation system and venturi element kit of claim 29, wherein the inlet angles of each of the venturi elements differ by at least 1 degree.

31. One or more Venturi elements can have the following options: a thread at the outlet portion; a central axial tube having an outer diameter relatively smaller than the diameter of said central portion; a propeller at or downstream of said outlet section; Vents, and 31. The aerosol generation system and venturi element kit of claim 29 or 30, comprising at least one of: a second airflow channel parallel to the airflow channel, the venturi element including a second inlet portion, a second central portion, and a second outlet portion, the second inlet portion configured to converge towards the second central portion, and the second outlet portion configured to diverge from the second central portion.

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